Multibit magnetic random access memory cell with improved read margin

FIELD: physics, computer engineering.

SUBSTANCE: magnetic random access memory (MRAM) cell comprises a magnetic tunnel junction comprising a tunnel barrier layer between a first magnetic layer having a first magnetisation direction, and a second magnetic layer having a second magnetisation direction being adjustable from a first direction to a second direction so as to vary junction resistance of the magnetic tunnel junction from a first to a second junction resistance level. Said magnetic tunnel junction further comprises a resistive switching element electrically connected to the magnetic tunnel junction and having a switching resistance which can be switched from a first to a second switching resistance level when a switching current passes through the resistive switching element. The MRAM cell resistance can have at least four different cell resistance levels depending on the resistance level of the junction resistance and the switching resistance. The tunnel barrier layer consists of a resistive switching element.

EFFECT: improved readability for a MRAM cell.

13 cl, 6 dwg, 3 ex

 

2420-182864RU/072

MULTI-bit CELL of the MAGNETIC random access MEMORY WITH IMPROVED FIELD READABILITY

The technical field to which the invention relates

The present invention relates to a cell of a magnetic random access memory (MOSE) based on magnetic tunnel transition with improved field readability, which can be used as a multibit cell MOSE. The present invention also relates to a method of recording multiple bits of data in the cell MOSE.

Description of the prior art

Storage devices that use materials with a variable resistor includes a resistive random access memory (ROSES), random access memory based on phase transition (RAM-OP), ferroelectric random access memory (SEOSU), magnetic random access memory (MOSE), etc. the above non-volatile memory devices can retain data on the basis of changes in resistance in the case of a material with a variable resistance (ROSES), material with a phase transition, having amorphous and crystalline state (RAM-OP), a ferroelectric material having different States of polarization (SEOSU), and/or film� magnetic tunneling transition from the ferroelectric material, having different magnetized States (MOSE).

Device based on the MOSE experiencing renewed interest, since the magnetic tunneling transitions can have a high magnetic resistance at ambient temperature. MOSE provides numerous advantages, including high speed write and read (up to a few nanoseconds), the energy independence and insensitivity to ionizing radiation. Were initially offered to the MINISTRY of health, containing the so-called "magnetoresistive effect" or "giant magnetic resistance (GMR). Such MOSE made in the form of a stack of several metal sheets in which alternated magnetic and non-magnetic. The GMR element exhibits a relatively large magnetoresistive change of attitude, but, unfortunately, requires the application of strong magnetic fields, and therefore require strong currents for recording and reading information.

Development of MOSE cells with a magnetic tunneling transition has significantly improved performance and mode of operation of these MOSE. These cells MOSE described in U.S. patent No. 5,640,343. Fig. 1 represents the traditional cell 1 MOSE containing magnetic tunnel junction 2 comprising a tunnel barrier layer 22 between the first ferromagnetic layer 21 and the second ferromagnetic layer 23. Magnetic Tunne�iny transition 2 is electrically connected at one end to the first line 4 current transfer and at the other end to the mos transistor 3 choice. Cell 1 MOSE shown in Fig. 1, further comprises a second line 5 current transfer, which is at right angles to the first line 4 current transfer. This configuration includes bus 7 between the magnetic tunnel junction 2 and the transistor 3 of the selection so that the second line 5 current transfer can be arranged in the direction of the magnetic tunnel junction 2.

The first and second ferromagnetic layers 21, 23 usually have different coercivity and preferably made of 3d metals such as Fe, Co, Ni and alloys thereof, possibly containing boron to make the amorphous ferromagnetic layers and align them to the interface. The tunnel barrier layer 22 is typically a thin insulating layer of aluminum oxide (Al2O3) or MgO. Each ferromagnetic layer 21, 23 can be combined with an antiferromagnetic layer (not shown), whose task is to capture the associated ferromagnetic layer so that the magnetization of the associated ferromagnetic layers 21, 22 exchange Pogranichnaya and cannot rotate freely, but only reversible by under the influence of an external magnetic field.

During a write operation, the traditional cell 1 MOSE transistor 3 selection mode is set to locked so that no current flows through the magnetic tunnel junction 2, the first �alevai current 41 runs in the first line 4 current transfer, producing a first magnetic field 42, and a second field current 51 passes in the second line 5 current transfer, producing a second magnetic field 52. The first and second magnetic fields 42, 52 adapted to switch the magnetization direction of the second magnetic layer 23, thereby generating the entry in cell 1 MOSE. In the matrix containing a plurality of cells 1 MOSE, only cell 1, located at the intersection of the first and second lines 4, 5 current transfer, is subjected to recording or conversion under the influence of a combination of the first and second magnetic fields 42, 52. Therefore, the write operation is selective.

Fig. 2 illustrates the cell 1 MOSE in another configuration, in which the cell 1 contains the second current 5. In this configuration, the write operation may include the transmission of spin-polarized current 31 entry through the magnetic tunnel junction 2 when the transistor 3 choice is in saturation mode. Spin-polarized current 31 record has a spin polarization in order to induce a local spin torque on the second magnetic layer 23.

During read operations current 32 read selectively passes through the magnetic tunnel junction 2 of the recorded cell 1, by setting the transistor 3 select the cell 1 in the saturation mode so that to measure the resistance (RICC) magnetic transition �onlinego transition 2. The magnetic resistance of the cell 1 MOSE can be determined by comparing the measured resistance (RICC) transition with a reference resistance measured for oporno MOSE cells (not shown). Low measured resistance RICCthe transition (or state of level 0) corresponds to the direction of magnetization of the second ferromagnetic layer 23 that is oriented parallel to the direction of magnetization of the first ferromagnetic layer 21, while the highest measured resistance RICCthe transition (or state level "1") corresponds to the direction of magnetization of the second ferromagnetic layer 23 that is oriented antiparallel to the magnetization of the first ferromagnetic layer 21. The difference between the high and low values of resistance (RICCswitching or tunneling magnetic resistance depends on the material constituting the ferromagnetic layers, and possibly from carrying out heat treatment of these ferromagnetic layers. Tunneling magnetic resistance of up to 70% can be achieved by an appropriate selection of materials and/or thermal treatment.

Were also suggested MOSE cells with multilevel operation status record allows you to record more than two levels "0" and "1" as described above. Such a cell MOSE surgery m�Neva recording condition is described in U.S. patent No. 6,950,335. Here the magnetization of the second ferromagnetic layer or the storage layer can be oriented in any intermediate direction between the direction that is parallel to and a direction which is antiparallel to the magnetization of the first ferromagnetic layer or pornoho layer. The orientation of the magnetization of the storage layer in the intermediate directions can be realized by the creation of magnetic fields with the appropriate relative intensity along the perpendicular directions of the first and second lines 4, 5 current transfer or a combination of magnetic fields produced in one of the lines 4, 5, with spin-polarized current record (for example in the case of the configuration of the cell MOSE in Fig. 1).

One drawback of the previously proposed MOSE cells with the operation of the multilevel recording conditions, however, is that the resistance corresponding to each condition can be relatively low.

Recently MOSE cells with enlarged field of readability were obtained using a tunnel barrier layer made of MgO, which provides high tunnel magnetic resistance. This increase of the tunneling magnetic resistance due to the crystalline structure of the MgO barrier, which may be monocrystalline or vysokotsentralizovannym with BCC (001) op�antasia crystals. More specifically, the magnetic resistance of the gap of more than about 150% at room temperature, obtained for magnetic tunnel junctions containing epitaxial MgO tunnel barrier layers with BCC-oriented electrodes of Fe or Co or containing textured tunnel barrier layers comprising polycrystalline BCC-oriented electrodes of CoFe or Co, or a structure containing CoFeB/MgO/CoFeB amorphous CoFeB electrodes. In the latter case, the tunneling barrier layer of MgO grown with vysokoorientirovannogo BCC (001) structure at the surface amorphous layer of CoFeB. After deposition requires a thermal annealing to induce identical structure in CoFeB electrodes to achieve a high magnetic resistance.

A brief summary of the invention

In the present invention, the cell of the magnetic random access memory (MOSE) may include: a magnetic tunnel junction containing a tunnel barrier layer between the first magnetic layer having a first magnetization direction, and a second magnetic layer having a second magnetization direction that is adjustable from a first direction to the second direction relative to the first magnetization direction, thereby to change the resistance re�ode magnetic tunneling transition from the first to the second resistance level of the transition, characterized in that said magnetic tunnel junction further comprises a resistive switching element electrically connected to the magnetic tunnel junction and having a resistance switch, which can be switched from the first to the second level of resistance switching, when the switching current passes through the resistive switching element, so that the resistance of the cell MOSE may have at least four different resistance of the cell depending on the resistance of transition and resistance switching.

In a variant implementation of the MOSE cell may further comprise a first transmission line current, is electrically connected to one end of the magnetic tunnel junction, and a selection transistor electrically connected to the other end of the magnetic tunneling transition; and the selection transistor may choose to send the switching current in the transmission line current in magnetic tunnel junction and a resistive switching element.

The resistive switching element may be in contact with the first or second magnetic layer or tunnel barrier layer may consist of a resistive switching element.

In a variant implementation of the resistive switching element can be made of a material selected from A 2O3, NiO, TiO2, MgO or an oxide of the perovskite type.

The present invention also relates to a method of recording multiple bits of data in a cell MOSE containing:

heating the magnetic tunnel transition to the high temperature threshold by passing the switching current in the magnetic tunnel junction, wherein the switching current has a heating value suitable for heating the magnetic tunnel junction with a high temperature threshold;

adjustment of the second direction of magnetization of the second magnetic layer to change the resistance of the transition from the first resistance level of transition to the second resistance level of the transition; and

switch resistance switch from a first resistance switch to the second level of resistance switching transmission switching current through the resistive switching element.

Mentioned switch resistance switch may include a change in the polarity of the switching current or may include transmission of a switching current having a magnitude of the first switch, which is lower than the heating value.

In a variant implementation of the switch resistance of the switch may contain a change in the magnitude of the switching current on the magnitude of the first switched�I to the value of the second switch.

In another embodiment, the implementation of the mentioned adjustment of the second direction of magnetization of the second magnetic layer may include the application of the first magnetic field, wherein the second direction of magnetization of the second magnetic layer is adjusted according to the first magnetic field.

In the next version of the implementation of the mentioned adjustment of the second direction of magnetization of the second magnetic layer may contain the transmission of the switching current in the magnetic tunnel junction, and the switching current is spin-polarized.

Cell MOSE described herein provides an improved field of readability in comparison with traditional cell MOSE by combining the transition resistance of the magnetic tunnel junction and the resistance of the resistive switching of the switching element.

In addition, cell 1 MOSE can also be used as a multibit cell MOSE to record at least four different resistance levels of the cell. The resistance levels of the multi-bit cell to cell MOSE exceed the levels that are reached in a traditional multi-bit cells MOSE.

Brief description of the drawings

The present invention would be better understood using the description of the embodiment given as an example�a and is illustrated by drawings, among them:

Fig. 1 shows a traditional cell MOSE;

Fig. 2 illustrates a cell MOSE in Fig. 1 in another configuration;

Fig. 3 represents the cell MOSE according to the embodiment of the implementation;

Fig. 4 represents a write operation of the cell MOSE in Fig. 3 according to the embodiment of the implementation;

Fig. 5 represents a write operation of the cell MOSE in Fig. 3 according to the second variant of implementation; and

Fig. 6 illustrates a write operation of the cell MOSE in Fig. 3 according to another embodiment of the implementation.

A detailed description of possible embodiments of the invention

Cell 1 of the magnetic random access memory (MOSE), according to the embodiment of the implementation shown in Fig. 3. The MOSE cell includes a magnetic tunnel junction 2 comprising a tunnel barrier layer 22, which is located between the first magnetic layer 21 having the first direction of magnetization and the second magnetic layer 23 having the second magnetization direction. The second direction of magnetization can be adjusted from the first to the second direction relative to the first magnetization direction in such a way as to change the resistance RICCthe transition of the magnetic tunnel junction 2 from the first to the second resistance level of the transition. In the example of Fig. 4 element mass storage device�TWA further comprises a first line 4 current transfer, electrically connected to one end of the magnetic tunnel junction 2, and the transistor 3 choice, electrically connected to the other end of the magnetic tunnel junction 2.

The second ferromagnetic layer or the storage layer 23 can be made of material having a planar magnetization, typically selected from the group consisting of permalloy (Ni80Fe20), Co90Fe10or other alloys containing Fe, Co or Ni. In a preferred embodiment of the second ferromagnetic layer 23 forms a link exchange with antiferromagnetic storage layer (not shown) so that the magnetization direction of the second ferromagnetic layer 23 exchange podmineno antiferromagnetic storage layer under low temperature threshold and thus that the direction of magnetization of the second ferromagnetic layer 23 can be freely oriented at high-temperature threshold. Antiferromagnetic storage layer can be made of an alloy on the basis of manganese, such as IrMn or FeMn, or any other suitable materials. High temperature threshold, usually located at or above the temperature of about 120°C.

The first magnetic layer 21 is a ferromagnetic layer, which may be made of an alloy based on Fe, Co or Ni. Preferably the first magnetic� layer 21 comprises a synthetic antiferromagnetic exchange Pogranichny layer, containing a first ferromagnetic reference layer and a second ferromagnetic reference layer, which are both made of an alloy based on Fe, Co or Ni and antiferromagnet are connected by inserting between them a non-ferromagnetic pornoho layer made of, e.g. made of ruthenium. In a preferred embodiment of the first magnetic layer or the support layer 21 antiferromagnet linked antiferromagnetic reference layer, the exchange podmagnichivaniem its direction of magnetization at temperatures above the high temperature threshold. Preferably, the antiferromagnetic reference layer is made of an alloy on the basis of Mn, such as PtMn or NiMn. The tunnel barrier layer 22 typically is a thin insulating layer of aluminum oxide (Al2O3) or MgO.

In an embodiment of the magnetic tunnel junction 2 further comprises a resistive switching element 62. In the example of Fig. 4 resistive switching element is a resistive layer 62 of switch in contact with the first ferromagnetic layer 21 on the side opposite that which is in contact with the tunnel barrier layer 22. The resistive switching element 62 has a resistance RPswitch that can be switched reversibly from the first to the second resistance switch�Oia, when the switching current 31 passes through the resistive switching element 62 (or when the voltage applied across the resistive switching element 62). Such a resistive switching element is often used in resistive random access memory devices (ROSE), where containing transition metal oxide resistive switching element is usually contained between two metal electrodes. Resistance RIthe MOSE cell from cell 1 MOSE then corresponds to the resistance RICCtransition and resistance RPswitch in series connection.

The resistive switching element 62 may be made of oxide containing aluminum oxide (Al2O3), NiO, TiO2or MgO, preferably with non-uniform oxygen or oxide of the perovskite type, including PCMO (PrOf 0.7CaThe 0.3MnO3) or SrTiO3, or any combination of these oxides. Depending on oxide and method of manufacturing the resistive switching element 62 may exhibit the behavior of a bipolar or unipolar switching resistance switching. In the case of a resistive switching element 62 with the behavior of the bipolar resistance switching, the resistance RPtoggle switches when the polarity of the switching TOCA, flowing through the resistive switching element 62, or voltage, is applied through a resistive switching element 62, from the first to the second polarity switching. Alternatively, in the case of a resistive switching element 62 having the behavior of unipolar switching resistance, resistance RPtoggle switches, when the change in the magnitude of the switching current 31 flowing through the resistive switching element 62, or voltage, is applied through a resistive switching element 62, from the first to the second magnitude switching.

The advantage of unipolar switching resistance is that there is no need for additional power transistor designed for switching the polarity of the current/voltage, and, thus, it is possible to make the cell 1 MOSE smaller size. The behavior of unipolar switching resistance can usually be obtained when the resistive switching element 62 is made of a transition metal oxide, while the behavior of the bipolar resistance switching can be obtained when the resistive switching element 62 is made of oxide of the perovskite type oxide or with a nonuniform stoichiometry on oxygen.

There might also be other configuration resistive layer 62 of switching. Example� resistive layer switch 62 may be in contact with the first or second ferromagnetic layer 21, 23 and possibly in contact with the tunnel barrier layer 22. Alternatively, the resistive layer switch 62 may be contained in the tunnel barrier layer 22. In a preferred embodiment of the tunneling barrier layer 22 consists of a resistive switching element 62. In the last configuration of the magnetic tunnel junction 2 contains a resistive layer 62 switching between the first and second magnetic layers 21, 23, or, in other words, the tunneling barrier layer 22 is made of oxide containing aluminum oxide, NiO, TiO2or MgO, preferably with non-uniform oxygen or oxide of the perovskite type, including PCMO (PrOf 0.7CaThe 0.3MnO3) or SrTiO3, or any combination of these oxides.

In the variant of implementation during the write operation of the cell 1 MOSE's first field current 41 is passed in the first line 4 current transfer, as described above. The first field current 41 produces a first magnetic field 42, which is attached to the second magnetic layer 23 in such a way that regulates the magnetization direction relative to the first magnetization direction in accordance with the first magnetic field 42. Resistance RICCthe transition of the magnetic tunnel junction 2 can then change from the first resistance level of transition to the second level resistance� " s transition. The transistor 3 options can be set in the mode locking in such a way as not to pass any current through the magnetic tunnel junction 2.

In a preferred embodiment of the write operation performed according to thermal method. More specifically, the operation of thermal recording contains the following steps:

heating the magnetic tunnel junction 2;

at the same time (or after a short delay) when the magnetic tunnel junction 2 high temperature threshold adjustment of the direction of magnetization of the second ferromagnetic layer 23; and

cooling the magnetic tunnel junction 2 when the low-temperature threshold, where the direction of magnetization of the second ferromagnetic layer 23 are frozen in the state of the record.

The adjustment of the direction of magnetization of the second ferromagnetic layer 23 can be realized by passing the first field current 41 in the first line 4 current transfer in such a way as to produce a first magnetic field 42 that is designed to adjust the direction of magnetization of the second ferromagnetic layer 23. The first magnetic field 42 can be maintained during cooling of the magnetic tunnel junction 2 and disable, once the magnetic tunnel junction 2 reaches the low temperature threshold.

Heating magnetic tunneling� transition 2 can be effected by passing a heating current via the first transmission line current in magnetic tunnel junction 2, when the transistor 3 selection mode is set to saturation. Cooling the magnetic tunnel junction 2 then carry out a disconnection of the heating current setting transistor 3 select mode locking.

The operation of thermal recording, as a rule, carried out the cell 1 MOSE, where the magnetic tunnel junction 2 further comprises an antiferromagnetic storage layer (not shown) forming the exchange relationship with the second ferromagnetic layer 23. In this configuration, the antiferromagnetic storage layer exchange podmaniczky the magnetization of the second ferromagnetic layer 23 under low temperature threshold and releases the magnetization of the second ferromagnetic layer 23 during high-temperature threshold. Such operation of thermal recording is described in U.S. patent No. 6,950,335. Operation of thermal recording allows you to reduce the first magnetic field 42 that is used to Orient the direction of magnetization of the second ferromagnetic layer 23, and thus to reduce the power consumption of the cell MOSE.

In a preferred embodiment of the write operation further comprises the step of reversibly switch the resistance RPswitching resistive element 62, the switching from the first to the second level of resistance switching. This can be done by passing the switching current 31 che�ez magnetic tunnel junction 2 and the resistive switching element 62, when the transistor 3 choice is in saturation mode.

During read operations current 32 read selectively passed through the magnetic tunnel junction 2 of the recorded cell 1 installing the transistor 3 select a cell in the saturation mode to measure resistance RIcell to the cell MOZ 1 MOZ. Resistance RIcell MOSE corresponds to the resistance RICCthe transition defined by the direction of magnetization of the second ferromagnetic layer 23 relative to the direction of magnetization of the first ferromagnetic layer 21 in series with a resistance RPswitch.

EXAMPLE 1

The write operation of the cell the MH is represented schematically in Fig. 4 according to the embodiment of the implementation. Operation record contains thermal heating of the magnetic tunnel junction 2 and the change in resistance RICCtransition by passing the first field current 41 in the first transmission line current 4 in such a way as to produce a first magnetic field 42. Resistance RPtoggle switch according to the polarity of the switching current 31 is passed in the magnetic tunnel junction 2, for example in the case of a resistive switching element 62 with the behavior of the bipolar resistance switching. Here the switching current 31 you can also use�may provide guidance as a heating current. In the present embodiment of the supposed resistance RPswitch can be switched when the switching current 31 is passed to the magnitude of the first switch, which is lower than the heating value of the switching current 31 is required for heating the magnetic tunnel junction with a high-temperature threshold.

More specifically, Fig. 4(a) represents the first stage of a write operation, where the switching current 31 is used with a heating value suitable for heating the magnetic tunnel junction 2 at the high temperature threshold. The first field current 41 is used with the first polarity thereby to produce a first magnetic field 42 with the first direction and to change the resistance RICCthe transition from the first to the second resistance level of the transition. For example, the magnetization of the second ferromagnetic layer 23 can be adjusted in a direction parallel to the direction of magnetization of the first ferromagnetic layer 21, thus corresponding to low RICC, nresistance transfer resistance RICCtransition. Since the switching current 31 is used with the heating value, higher than the first value, the resistance RPswitch will switch to the first resistance level switch according to the polarity perekluchaus� current 31, for example the low level of RP, nresistance switching.

In the second stage, shown in Fig. 4(b), the first magnetic field 42 is not used, and the resistance RICCtransition remains at its low RICC, nthe resistance of the transition. The switching current 31 is held in the magnetic tunnel junction 2 when the polarity is changed in comparison with the polarity in step (a) thereby to switch the resistance RPswitching to a high level of RP,resistance switching. Here the switching current 31 is preferably passed with the smaller value of the first switch, as shown in step (b).

In the third stage, shown in Fig. 4(c), the first field current 41 is used with the second polarity, thereby to produce a first magnetic field 42 with a second direction opposite to the first, thus to adjust the magnetization of the second ferromagnetic layer 23 in the direction antiparallel to the magnetization of the first ferromagnetic layer 21. This leads to a high level of RThe ICC, inresistance transfer resistance RICCtransition. The switching current 31 is held magnetic tunnel junction 2 with the same polarity as in step (b), but with the first value, thereby to heat the mA�netic tunnel junction at the high temperature threshold. The polarity of the switching current 31 is the same as in step (b), the resistance RPswitching remains unchanged at its high level of RP,resistance.

In the fourth stage shown in Fig. 4(d), the first magnetic field 42 is not used, and the resistance RICCtransition remains at a high level of RThe ICC, inthe resistance of the phase transition (c). The switching current 31 is held at the value of the first switch, and its polarity is changed in comparison with the polarity in step (c), so that the resistance RPswitch is switched to the low level of RP, nresistance switching. Accordingly, four different resistance cell resistance RIcell MOSE recorded in cell 1 MOSE by combining two levels of resistance the resistance RICCtransition and resistance RPswitch.

EXAMPLE 2

Fig. 5 illustrates the operation of thermal recording MOSE cell 1 according to the second variant implementation. In this embodiment, the implementation is assumed that the resistance RPtoggle switch according to the magnitude of the switching current 31, for example in the case of a resistive switching element 62 having the behavior of unipolar switching resistance. More specifically, it is assumed that the resistance R Pswitch is switched to the low level of RP, nresistance switching, when the switching current 31 is passed to the magnitude of the first switch, and is switched to the high level of RP,resistance switching, when the switching current 31 is passed with the value of the second switch exceeds the value of the first switch. In addition, it is assumed that the values of the first and second switch is lower than the heating value.

In step (a) shown in Fig. 5, the first field current 41 runs in the first line 4 current transfer in such a way as to produce a first magnetic field 42 in the direction intended for establishing a resistance RICCthe transition to low RICC, nthe resistance of the transition (similar to the step in Fig. 4(a)). The switching current 31 is held in the magnetic tunnel junction 2 when the heating value, heating the magnetic tunnel junction 2 at the high temperature threshold and switching resistance RPswitching to its high level of RP,resistance switching (this heating value is above the value of the second switch).

Fig. 5(b) the first magnetic field 42 is not used, and the resistance RICCtransition remains low RICC, nthe resistance of the transition. The switching current 31 is passed �ri the value of the first switch, switching resistance RPswitching to its low RP, nresistance switching. Fig. 5(c) of the first field current 41 is applied with a second polarity so that the resistance RICCthe transition is changed to the high level of RThe ICC, inthe resistance of the transition. The switching current 31 is passed when the heating value, heating the magnetic tunnel junction 2 at the high temperature threshold and switching resistance RPswitching to its high level of RP,resistance switching.

EXAMPLE 3

In yet another variant implementation, shown in Fig. 6, the operation of thermal recording cells 1 MOSE contains the change in resistance RICCtransition by passing the switching current 31 in the magnetic tunnel junction 2 when the condition of the spin polarization. The spin-polarized switching current 31 induces a local spin torque on the second magnetic layer 23, which is to reduce the magnetization direction according to the polarity of the spin-polarized current. Spin-polarized current should be flowing in the heating value thus to heat the magnetic tunnel junction 2 at the high temperature threshold. In this embodiment, the implementation suggested that the resistive switching element 62 has a bipolar behavior pyo�of clucene resistance and that the heating value is lower than the magnitude of the first switch.

More specifically, at the stage shown in Fig. 6(a), the switching current 31 is passed when the value of the first switch so that switch resistance RPswitching, for example at low RP, nresistance switching, in accordance with the polarity of the switching current 31. The magnitude of the first switch is, however, too low, to adjust the direction of magnetization of the second magnetic layer 23, and thus changes the resistance RICCtransition.

Fig. 6(b) the magnitude of the spin-polarized switching current 31 to increase the heating value such that the magnetization direction of the second magnetic layer 23 can be adjusted, for example at low RICC, nthe resistance of the transition according to the polarity of the switching current 31. Since the polarity of the switching current 31 is the same as in step (a), the resistance switch resistance RPthe switch remains unchanged. In step (c) spin-polarized switching current 31 is passed with the change in polarity relative to the polarity of the phases (a) and (b) so as to switch the resistance RPswitching to a high level of RP,resistance switching. When SIZ�e of the switching current 31, which is the magnitude of the first switch, the resistance RICCtransition remains low RICC, nthe resistance of the transition. In step (d) the magnitude of the spin-polarized switching current 31 is increased to the heating value so that the resistance RICCthe transition can be adjusted with a high level of RThe ICC, inthe resistance of the transition. Resistance RPswitching remains high RP,resistance switching.

As illustrated by three of the above variants of implementation, at least four different levels of cell resistance for resistance RIcell MOSE can be recorded in cell 1 MOSE by combining two resistance levels for the resistance RICCtransition and resistance RPswitch. This is achieved by appropriate changes in the polarity of the first field current 41 and the switching current 31 and the magnitude of the switching current 31. This goal is also achievable with appropriate changes in the polarity and magnitude of the switching current when the write operation is carried out using a spin-polarized current, and a resistive switching element 62 has the behavior of the bipolar resistance switching. This goal is also achievable with appropriate change only the magnitude of the switching current�, when a write operation is carried out using a spin-polarized current, and a resistive switching element 62 has the behavior of unipolar switching resistance. There is a condition that the magnitude of the switching current 31 in which a resistance RPtoggle switches (first and possibly second value) differs from the value at which you can change the resistance RICCtransition (heating value).

The present invention can be realized in various modifications and alternative forms, and specific variations in its implementation is presented in the form of examples and the drawings and described in detail herein. It should be understood, however, that the present invention is not subject to the limitation described specific forms or methods, but, on the contrary, the present invention is considered applicable to all modifications, equivalents and alternatives.

For example cell 1 MOSE may contain a second line 5 current transfer, as shown in the example in Fig. 1. Second field current 51 can then pass on the second line 5 current transfer, producing a second magnetic field 52. The magnetization direction of the second magnetic layer 23 can then be adjusted with the joint action of the first and second magnetic fields 42, 52. In this configuration, the magnetization of the second�th ferromagnetic layer 23 can be adjusted in any intermediate directions by appropriate management of the relative intensity and, perhaps the polarity of the first and second field currents 41, 51 along the perpendicular directions of the first and second lines 4, 5 current transfer. Alternatively, regulation of the magnetization of the second ferromagnetic layer 23 in any intermediate directions can be realized by a combination of the magnetic field created in one of the lines 4, 5 spin-polarized current account 33. This can additionally be combined with one of the write operations described above that allows you to record more than four levels of resistance cells in cell 1 MOSE. Alternatively, a second line 5 current transfer can be positioned above the first line 4 current transfer, for example parallel to the latter.

Cell 1 MOSE, described herein, provides an improved field of readability in comparison with traditional MOSE cells, because the resistance RICCthe transition of the magnetic tunnel junction 2 is combined with resistance RPswitching resistive element 62, the switch 22. Resistance levels for cell resistance RIcell MOSE, thus, exceed the levels achieved in the traditional multi-bit cells MOSE.

According to a variant of implementation, which was not provided with a memory device comprises a matrix containing a plurality of cells 1 MOSE in accordance with vari�ntami implementation. Cell 1 MOSE can be connected through one or more of the first 4 lines of the current transfer. The storage device may further contain one or more numeric tire connected to the gate of the transistor 3 select each of the cells 1 MOSE, thus to control the transistor 3 of choice, providing selective reading or writing one of the MOSE cells 1.

Conditional numeric and alphabetic notation

1 - cell MOSE

2 - magnetic tunnel junction

21 - the first ferromagnetic layer, the support layer

22 - tunneling barrier layer

23 - the second ferromagnetic layer, a storage layer

3 - transistor selection

31 - spin-polarized current account switching current

32 - current reading

4 - the first transmission line current

41 is the first field current

42 - the first magnetic field

5 - second transmission line current

51 - second field current 52 - second magnetic field

62 - resistive element switching

7 - bus

RI- the resistance of the cell MOSE

RP- resistance switch

RICC- the resistance of the transition

1. The cell of the magnetic random access memory (MOSE), comprising: a magnetic tunnel junction containing a tunnel barrier layer between the first magnetic layer having a first magnetization direction, and a second magnetic �Laem, having a second magnetization direction that is adjustable from a first direction to the second direction relative to the first magnetization direction, thereby to change the resistance of the junction magnetic tunneling transition from the first to the second resistance level of the transition;
over and above the magnetic tunnel junction further comprises a resistive switching element electrically connected to the magnetic tunnel junction and having a resistance switch, which can be switched from the first to the second level of resistance switching, when the switching current passes through the resistive switching element, so that the resistance of the cell MOSE may have at least four different resistance of the cell depending on the resistance level of the transition and the resistance of the switch, wherein the tunneling barrier layer comprises a resistive switching element.

2. Cell memory device according to claim 1, further comprising a first transmission line current, is electrically connected to one end of the magnetic tunnel junction, and a selection transistor electrically connected to the other end of the magnetic tunneling transition; and the selection transistor may choose to send the switching current per transceiver�and current in magnetic tunnel junction and a resistive switching element.

3. Cell memory device according to claim 1, in which the resistive switching element is in contact with the first or second magnetic layer.

4. Cell memory device according to claim 1, in which mentioned the resistive switching element has a resistance of bipolar or unipolar switching.

5. Cell memory device according to claim 1, in which the resistive switching element made of a material selected from Al2O3, NiO, TiO2, MgO or an oxide of the perovskite type.

6. Cell memory device according to claim 5, in which the oxide perovskite is one of Pr0,7CA0,3MnO3or SrTiO3.

7. A storage device comprising a plurality of MOSE cells in which each cell MOSE includes a magnetic tunnel junction comprising a tunnel barrier layer between the first magnetic layer having a first magnetization direction, and a second magnetic layer having a second magnetization with a second magnetization is adjustable from a first direction to the second direction relative to the first magnetization direction in such a way as to change the resistance of the junction magnetic tunneling transition from the first to the second resistance level of the transition; and mentioned magnetic tunnel per�stroke further comprises a resistive switching element, electrically connected to the magnetic tunnel junction and having a resistance switch, which can be switched from the first to the second level of resistance switching, when the switching current passes through the resistive switching element, so that the resistance of the cell MOSE may have at least four different levels of resistance depending on the resistance at the transition resistance and the resistance of the switch, wherein the tunneling barrier layer comprises a resistive switching element.

8. A method of recording multiple bits of data in a cell MOSE containing magnetic tunnel junction comprising a tunnel barrier layer between the first magnetic layer having a first magnetization direction, and a second magnetic layer having a second magnetization with a second magnetization is adjustable from a first direction to the second direction relative to the first magnetization direction in such a way as to change the resistance of the junction magnetic tunneling transition from the first to the second resistance level of the transition; and mentioned magnetic tunnel junction further comprises a resistive switching element electrically connected to the magnetic tunnel junction and having abrasion resistance�tion switch, which can be switched from the first to the second level of resistance switching, when the switching current passes through the resistive switching element, wherein the tunneling barrier layer comprises a resistive switching element, wherein the method includes:
heating the magnetic tunnel transition to the high temperature threshold;
after reaching the magnetic tunnel crossing the high temperature threshold, the regulation of the second direction of magnetization of the second magnetic layer to change the resistance of the transition from the first resistance level of transition to the second resistance level of the transition; and
switch resistance switch from a first resistance switch to the second level of resistance switching transmission switching current through a resistive switching element such that the resistance of the cell MOSE may have at least four different levels of resistance depending on the resistance at the transition resistance and resistance switching.

9. A method according to claim 8, in which the said heating of the magnetic tunnel junction with a high-temperature threshold contains a deletion of the switching current with the heating value of the magnetic tunnel junction.

10. A method according to claim 8, in which the mentioned R�sistemny the switching element is a bipolar resistance switching and in which the said switch resistance switch includes a change in the polarity of the switching current.

11. A method according to claim 8, in which the mentioned resistive switching element has a resistance of unipolar switching, and in which the said switch resistance switch provides transmission of a switching current having a magnitude of the first switch, for switching the resistance of the switch to the first resistance level shifter and the transmission of the switching current value of the second switch, to switch the resistance of the switching to the second resistance switch, and the second switch is higher than the value of the first switch, and lower than the heating value.

12. A method according to claim 8, in which the mentioned regulation of the second magnetization direction includes applying a first magnetic field, wherein the second direction of magnetization of the second magnetic layer is adjusted respectively to the first magnetic field.

13. A method according to claim 8, in which the mentioned regulation of the second direction of magnetization of the second magnetic layer contains a deletion of the switching current in the magnetic tunnel junction, wherein switching current is spin-polarized.



 

Same patents:

FIELD: physics.

SUBSTANCE: invention relates to microelectronics. An element library based on complementary metal-oxide-semiconductor (MOS) transistors, comprising a p-type substrate and an n-type pocket, n- and p-type MOS transistor active regions, p+ and n+ contacts for the zero potential and supply bus, further includes an extended n+ protection located along the outer boundary of the pocket and which fills the entire free area of the pocket, as well as an annular p+ protection around each of the n-type transistor groups with drain/gate regions of transistors with different potential, which fills the entire free area of the substrate.

EFFECT: creating a radiation-resistant element library based on complementary metal-oxide-semiconductor transistors with a smaller area of elements on the chip and faster operation.

5 dwg

FIELD: information technology.

SUBSTANCE: read signal is applied to a bit line connected to a memory array including a plurality of memory cells, each of the plurality of memory cells having a magnetic tunnel junction (MTJ) device; positive voltage is applied to a selected word line connected to a selected memory cell of the memory array; negative voltage is applied to unselected word lines connected to the memory array; and the negative voltage is applied to each word line during a standby state.

EFFECT: reduced stray current in magnetic random access memory.

25 cl, 7 dwg

FIELD: information technologies.

SUBSTANCE: nonlinear memory cell represents arbitrary geometrically shaped set of arbitrary number of memory elements of arbitrary type which are connected by data bus lines in arbitrary order. The memory elements may be distributed over arbitrary surface or in arbitrary volume.

EFFECT: increase in data processing rate.

1 dwg

FIELD: information technology, physics.

SUBSTANCE: Boolean logic function is constructed when recording the memorising information in the accomplished normal disjunctive form. The argument of this form is the address of memorised information and its value is the memorised information. After that the Boolean logic function gets converted into Zhegalkin polynomial, then the number of elementary Boolean operations, being a part of Zhegalkin polynomial, gets minimised, and then the minimised Zhegalkin polynomial gets realised on the programmed integrated circuit logic.

EFFECT: decrease of general-circuit expenditures for memorising the digital information.

2 tbl

FIELD: electric engineering, possible use in new generation of computers, informational communication systems, intelligent sensors, bio-passports, control systems.

SUBSTANCE: memory element based on planar Hall effect is made on a substrate, on which positioned serially are dielectric layer, recording ferromagnetic film, consisting of first protective layer, ferromagnetic nanostructure with light magnetization axis, directed along the length of film and second protective layer, first isolating layer, record conductor, second isolating layer, and contains a reading cross-shaped magnetic structure based on planar Hall effect on dielectric layer, which structure consists of third protective layer, magnetic nanostructure and fourth protective layer, and also of third isolating layer, positioned on record conductor, fourth isolating layer, positioned above record conductor, on top of which the reading conductor is positioned, mounted above the cross-shaped reading structure based on planar Hall effect and along recording ferromagnetic film.

EFFECT: reduced error of measurements, increased trustworthiness of accumulation and processing of information.

2 dwg

FIELD: technology for recording data, linked with other data.

SUBSTANCE: data production device has module for assigning numeric value, meant for assigning from number of multiple numeric values, stored on data carrier, of numeric value, appropriate for data file, subject for extraction, while numeric value is additional basic n value, where n - integer value higher than one. Device also has module for forming path name, meant for forming name by insertion of symbol, appropriate for numeric value, into each preset position in given formed symbols string, and receiving module, meant for extraction of data file, if in data carrier additional file is present with path name, formed by path name forming module.

EFFECT: decreased data-occupied space in memory.

4 cl, 12 dwg

The memory cell // 2224356
The invention relates to the field of pulse technique and can be used in devices of computer engineering and control systems

The memory cell // 2222100
The invention relates to the field of pulse technique and can be used in devices of computer engineering and control systems

The invention relates to programmable memory elements, to a method and device for reading, writing, and programming

The memory cell // 2214037
The invention relates to the field of pulse technique and can be used in devices of computer engineering and control systems

FIELD: technology for recording data, linked with other data.

SUBSTANCE: data production device has module for assigning numeric value, meant for assigning from number of multiple numeric values, stored on data carrier, of numeric value, appropriate for data file, subject for extraction, while numeric value is additional basic n value, where n - integer value higher than one. Device also has module for forming path name, meant for forming name by insertion of symbol, appropriate for numeric value, into each preset position in given formed symbols string, and receiving module, meant for extraction of data file, if in data carrier additional file is present with path name, formed by path name forming module.

EFFECT: decreased data-occupied space in memory.

4 cl, 12 dwg

FIELD: electric engineering, possible use in new generation of computers, informational communication systems, intelligent sensors, bio-passports, control systems.

SUBSTANCE: memory element based on planar Hall effect is made on a substrate, on which positioned serially are dielectric layer, recording ferromagnetic film, consisting of first protective layer, ferromagnetic nanostructure with light magnetization axis, directed along the length of film and second protective layer, first isolating layer, record conductor, second isolating layer, and contains a reading cross-shaped magnetic structure based on planar Hall effect on dielectric layer, which structure consists of third protective layer, magnetic nanostructure and fourth protective layer, and also of third isolating layer, positioned on record conductor, fourth isolating layer, positioned above record conductor, on top of which the reading conductor is positioned, mounted above the cross-shaped reading structure based on planar Hall effect and along recording ferromagnetic film.

EFFECT: reduced error of measurements, increased trustworthiness of accumulation and processing of information.

2 dwg

FIELD: information technology, physics.

SUBSTANCE: Boolean logic function is constructed when recording the memorising information in the accomplished normal disjunctive form. The argument of this form is the address of memorised information and its value is the memorised information. After that the Boolean logic function gets converted into Zhegalkin polynomial, then the number of elementary Boolean operations, being a part of Zhegalkin polynomial, gets minimised, and then the minimised Zhegalkin polynomial gets realised on the programmed integrated circuit logic.

EFFECT: decrease of general-circuit expenditures for memorising the digital information.

2 tbl

FIELD: information technologies.

SUBSTANCE: nonlinear memory cell represents arbitrary geometrically shaped set of arbitrary number of memory elements of arbitrary type which are connected by data bus lines in arbitrary order. The memory elements may be distributed over arbitrary surface or in arbitrary volume.

EFFECT: increase in data processing rate.

1 dwg

FIELD: information technology.

SUBSTANCE: read signal is applied to a bit line connected to a memory array including a plurality of memory cells, each of the plurality of memory cells having a magnetic tunnel junction (MTJ) device; positive voltage is applied to a selected word line connected to a selected memory cell of the memory array; negative voltage is applied to unselected word lines connected to the memory array; and the negative voltage is applied to each word line during a standby state.

EFFECT: reduced stray current in magnetic random access memory.

25 cl, 7 dwg

FIELD: physics.

SUBSTANCE: invention relates to microelectronics. An element library based on complementary metal-oxide-semiconductor (MOS) transistors, comprising a p-type substrate and an n-type pocket, n- and p-type MOS transistor active regions, p+ and n+ contacts for the zero potential and supply bus, further includes an extended n+ protection located along the outer boundary of the pocket and which fills the entire free area of the pocket, as well as an annular p+ protection around each of the n-type transistor groups with drain/gate regions of transistors with different potential, which fills the entire free area of the substrate.

EFFECT: creating a radiation-resistant element library based on complementary metal-oxide-semiconductor transistors with a smaller area of elements on the chip and faster operation.

5 dwg

FIELD: physics, computer engineering.

SUBSTANCE: magnetic random access memory (MRAM) cell comprises a magnetic tunnel junction comprising a tunnel barrier layer between a first magnetic layer having a first magnetisation direction, and a second magnetic layer having a second magnetisation direction being adjustable from a first direction to a second direction so as to vary junction resistance of the magnetic tunnel junction from a first to a second junction resistance level. Said magnetic tunnel junction further comprises a resistive switching element electrically connected to the magnetic tunnel junction and having a switching resistance which can be switched from a first to a second switching resistance level when a switching current passes through the resistive switching element. The MRAM cell resistance can have at least four different cell resistance levels depending on the resistance level of the junction resistance and the switching resistance. The tunnel barrier layer consists of a resistive switching element.

EFFECT: improved readability for a MRAM cell.

13 cl, 6 dwg, 3 ex

FIELD: physics, computer engineering.

SUBSTANCE: invention relates to computer engineering. A method of making static random access memory includes arranging data bit storage units and data read buses and data write buses in space, wherein a memory cell is structurally divided into three types of modules: a data bit storage module, a write port module and a read port module, wherein the write port module is arranged separately from the storage module and connected to the input of the data bit storage module, and the read port module is arranged separately from the storage module and connected to the output of the storage module.

EFFECT: improving noise-immunity of the RAM by reducing the capacitance of parasitic capacitors between components of the device.

3 cl, 3 dwg

FIELD: physics, computer engineering.

SUBSTANCE: invention can be used as ternary content addressable memory. A magnetic random access memory (MRAM) cell includes a first tunnel barrier layer enclosed between a soft ferromagnetic layer, having free magnetisation, and a first hard ferromagnetic layer, having a first storage magnetisation; a second tunnel barrier layer enclosed between a soft ferromagnetic layer and a second hard ferromagnetic layer having a second storage magnetisation; wherein the first storage magnetisation can be freely oriented at a first high predetermined temperature threshold and the second storage magnetisation can be freely oriented at a second predetermined high temperature threshold; wherein the first high predetermined temperature threshold is higher than the second predetermined high temperature threshold.

EFFECT: enabling use of a MRAM cell as ternary content addressable memory (TCAM) with a smaller cell size.

15 cl, 2 dwg, 2 tbl

FIELD: computer engineering.

SUBSTANCE: invention relates to computer engineering and can be used in units os multi-port static CMOS RAM. Memory cell for complementary microcircuit of metal-oxide-semiconductor structure RAM includes trigger, consisting of two groups of transistors, ports data recording and reading ports arranged on-chip integrated circuit, outputs of data recording ports are connected to corresponding outputs of two groups of transistors of trigger, according to the invention cell is equipped with two inverters and two inverters to third state, first outputs of first and second groups of transistors are connected to trigger input of first inverter, second outputs of first and second groups of transistors are connected to trigger input of second inverter, third output of first group of transistors of trigger and third output of second groups of transistors of trigger are connected to first inputs of first and second inverters to third state, output of first inverter is connected to second input of first and third input of second inverters to third state, output of second inverter is connected to third input of first and second input of second inverters to third state outputs of which are connected to inputs of data read ports.

EFFECT: technical result consists in improvement of reliability of reading data from memory cell at impact of single nuclear particles in conditions when trigger memory cell based on two groups of transistors is in unbalanced state.

2 cl, 3 dwg, 3 tbl

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