A storage element on the spin-valve magnetoresistive effect
(57) Abstract:The invention relates to the field of computer technology, in particular to magnetic storage devices with random access. The essence: a storage element containing two discretetime conductors, such as copper, are located respectively between the three-layer strip and the first protective layer and three-layer strip and the second insulating layer and separated on the plot, free from the three-layer strip, the third insulating layer, and a thin-film magnetoresistive layers have different values of the field magnetic anisotropy and the ratio of the larger field magnetic anisotropy smaller is at least four. 3 Il. The present invention relates to the field of computer technology, in particular to a magnetic thin film storage devices with random access.Known magnetoresistive memory (see U.S. Patent N 4751677, M CL5G 11 C 11/150) using anisotropic magnetoresistive (AMR) effect, on the basis of the two-layer magnetic films FeNiCo with solid state control circuits on the same substrate. The disadvantages of memory cells is high requirements for technology to obtain acceptable signal reading.Known (see A. V. Pohm, C. S. Comstock. Memory implications of the spin-value effect in soft Board. J. Appl. Phys. 69(8), 1991, p.p. 5760-5762) a storage element on the spin-valve magnetoresistive (SVMR) effect, we adopted as the prototype of the proposed technical solutions, designed as a multi-layer strip with the main part of the two magnetoresistive films of Fe15Ni65Co20separated by a layer of copper, which is in the reading mode is included in the circuit of the bridge. When SWMR-the effect of the change in resistance depends on the angle between the vectors of magnetization of adjacent magnetic films separated by a layer of copper. Value SVMR effect on samples with films of Fe15Ni65Co20reaches (5,5-7,5)% when the thickness of the magnetic film of about 8 nm and the thickness of the copper layer of 5 nm. However, to use SWMR-effect, it is necessary to paramagnetically only one magnetic tape. To do this, increase the coercive force of one of the films due to the exchange interaction with additional magnetic film, such as FeMn film. In the above-mentioned storage element uses two film FeNiCo, and in his description not specified the way to obtain films with different values of magnetic anisotropy or coercive what about the influence of the copper film, because the current in the strip runs parallel to the two magnetoresistive or copper film, and the resistance of the copper film always small compared with the resistance of the magnetic films.The technical result is the increased functionality of the storage element and the simplification of its manufacturing technology.The technical result is achieved in that the storage element on the spin-valve magnetoresistive effect containing a silicon substrate on which are successively arranged first insulating layer, the first protective layer, three-layer strip with pointed ends, consisting of two spaced parallel to the substrate a thin-film magnetoresistive layers with the axis of easy magnetization directed along the strip and located between the thin-film layer of copper and a layer of three-layer strip is second insulating layer, which is formed conductor and the second protective layers is further provided with two discretetime conductors, such as copper, located respectively between the three-layer strip and the first protective layer and three-layer strip and the second insulating layer and divided between esistive layers sandwich the strips have different values of the field magnetic anisotropy. The ratio of the larger field magnetic anisotropy smaller is at least four.Salient features of the above together is the presence of two discrediting conductors located on both sides of the three-layer strip and separated by an additional insulating layer, and performing a thin-film magnetoresistive layers with different values of the field magnetic anisotropy.The essence of the invention lies in the fact that the proposed structure provides a current flow perpendicular to surfaces of layers of the element, and not along them, as in the known device, and thus, thin-film copper layer between the magnetoresistive layer in three-layer strip is connected in series to them, not in parallel, eliminating the shunting effect of copper layer and increases the observed Suprefact that, in turn, leads to a sharp increase in signal reading. The use of magnetoresistive layers with different values of the field magnetic anisotropy eliminates the need for additional FeMn film to increase the coercive force of one of the magnetic films due to exchange vzaimodei SVMR effect in section, in Fig. 2 storage elements included in the circuit of the bridge, top view, and Fig. 3, the circuit element in the trigger.A storage element for SVMR effect contains (Fig. 1) the silicon substrate 1, on which are positioned successively the first insulating layer 2, the first protective layer 3, the first discreditably conductor 4, the third insulating dielectric layer 5, a three-layer strip with pointed ends, consisting of two layers of magnetoresistive magnetic films 6, 7 and a copper layer 8. On top of the three-layer strip is the second discreditably Explorer 9. Above are consistently the second insulating layer 10, the conductive layer 11 and the second protective layer 12.When reading in a bridge circuit uses four magnetoresistive storage element 13-16 (Fig. 2), and the use of trigger schemes strips 17, 18 with conductors 19, 20 is connected to the trigger of the transistors 21, 22 with the keys 23-26 (Fig. 3).Working storage element is as follows. In the absence of current through the three-layer strip (touch current) and the current through the conductor 11, the magnetization in the two magnetic films is or antiparallel to each other when recorded in sapam, 9 leads to the fact that the touch current to flow perpendicularly through the three-layer strip, and not along it, as was in the previous structures, in which the pads were on the pointed ends of the strips. Thus, current passes successively through two magnetoresistive and the copper film, and not in parallel.We introduce the notion of the value of physical SVMR effect, characterized by magnitude , and the magnitude of the observed SVMR effect, characterized by the value of (/)neb. Under physical SVMR effect will be to understand the magnitude of the effect inherent in the magnetoresistive strip with resistance Rm:
where Rmthe maximum change in resistance strips.Under the observed SVMR effect will be to understand the magnitude of the measured effect in a concrete structure with a resistance R and a maximum resistance change R:
In the case of already known storage element, as mentioned above, two magnetic and copper foils (RCu) connected in parallel and the resistance of this structure is:
For (/)(1)neb= (5,5-7,5) % and p (0,2-0,25)
(/)Phys= (23-33) %
In the proposed storage element two magnetic and copper foils are connected in series and the total resistance R(2element is:
R2)(Rm)=2Rm+RCu< / BR>The resistance change is:
< / BR>Here
< / BR>Finally:
(/)(2)neb= 2(/)Phys/(2+RCu/Rm) (4)
Thus, the ratio between the observed values SVMR effect in the proposed and known storage elements taking into account expressions (2)-(4) the following:
< / BR>This leads to the fact that for the ratio Rm/RCu=4-5 observed SVMR effect increases with (5,5-7,5)% to (20-30)% However, this direction of flow of the touch current disappears its impact on the alternating magnetization of the magnetic films. Remains in effect only for the current through the conductor 11, which creates a magnetic field along the axis of easy magnetization (OLN). Therefore, in the recording mode is pulse necessary to write "0" or "1" polarity only in the conductor 11. Because of the differences before overwrite "0" to "1". With increasing drive current will occur alternating magnetization film with a large value of the field magnetic anisotropy, which would mean reverse alternating magnetization "1" to "0", and this is unacceptable. Thus, when overwriting "0" to "1" there is some range of acceptable currents account. When rewriting "1" to "0" is current of reverse polarity, which paramagnetism film with the least amount of field magnetic anisotropy, the film is more value field magnetic anisotropy field cannot paramagnetic. Restrictions on the magnitude of the currents account still.
FIELD: magnetic microelements and nanostructures, possible use in sensors of magnetic field and current, recording and logical elements, galvanic cross couplings and spin transistors based on multi-layered thin-film nanostructures with anisotropic or gigantic magneto-resistive effect.
SUBSTANCE: multi-layer thin-film magneto-resistive nanostructure contains first protective layer, upon which first magneto-soft film is positioned, separating non-magnetic layer on top of first magneto-soft film, on top of which in turn second magneto-soft film and second protective layer are positioned, between second magneto-soft film and second protective layer a layer of silicon carbide is positioned, while separating non-magnetic layer is thick enough to prevent interaction of exchange between magneto-soft films.
EFFECT: creation of multi-layer thin-film magneto-resistive nanostructure, having various reverse magnetization fields of magnetic layers included in it, having high reproducibility of magnetic parameters and expanded functional capabilities.
FIELD: magnetic micro- and nano-elements, possible use in indicators of magnetic field and current, memorizing and galvanic elements, galvanic decoupling and spin transistors based on multi-layered nanostructures with magneto-resistive effect.
SUBSTANCE: in multi-layered magneto-resistive nanostructure composed of magnetic nano-islands, consisting of N pairs of alternating layers, each pair containing layers of nano-islands with different values of magnetic reversal field of magnetic materials positioned on dielectric layer and protected by a solid dielectric layer on top. Such a multi-layered magneto-resistive nanostructure consists of nano-islands positioned separately within each layer. Nano-islands of each layer may contact nano-islands of upper and lower layers, with resulting magnetic interaction between them.
EFFECT: production of multi-layered magneto-resistive nanostructure using magnetic nano-islands, having high value of magneto-resistive effect in small magnetic fields and having high reproducibility of magnetic parameters for serial production of nano-elements based on aforementioned structure.
2 cl, 6 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention can be applied as external and internal data carrier furnished with reading device. Offered device contains cylindrical body consisting of bottom and top cover, and the platform superadjacent with the body, cylindric cartridge, contact reading unit in the form of read and record head assembly system embedded from above and from below in rectangular frames interconnected with thin pins. The device is supplied with rotary engine simultaneous rotating platform and data carrier cartridge fixed thereupon. Lower rigid segment of the engine is fixed on body bottom, while its mobile part is mounted on body axis and rigidly connected to the platform. The head assembly contains the case clamped to constant magnets with sliding enclosure, and the head case is supplied with flexible belts with their end containing pads with the heads in-between with contacts providing signal transmission from heads through the converter to mobile contacts of heads. Each head is connected with two strings supplied with reading signal transmission paths. Heads are integrated in units with magnet-insulating walls and spaced between upper and lower frames in parallel to spokes supplied with electromagnetic windings interacting with constant magnets of the heads. The cover of the device body accommodates barometric filter with the filter thereunder.
EFFECT: higher capacity and reliability of the device.
4 cl, 9 dwg
SUBSTANCE: multilayer magnetoresistive composite nanostructure has several sets of alternating layers of magnetically soft and magnetically hard nanoclusters insulated at the top and bottom by a continuous dielectric layer of antiferromagnetic material. One set has an antiferromagnetic layer, a layer of magnetically soft nanoclusters, an antiferromagnetic layer, a layer of magnetically hard nanoclusters, and a antiferromagnetic layer, where thickness of the nanocluster film is equal to 0.8-2.5 nm. The number of said sets of layers is between 2 and 5.
EFFECT: design of a magnetoresistive nanostructure whose production technology guarantees required parametres, giant magnetoresistive effect in the material with working capacity under high temperature conditions, and high reproducibility of parametres under batch production conditions.
5 cl, 2 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to computer engineering. A method of writing in a memory device comprising a plurality of magnetoresistive random access memory (MRAM), wherein each MRAM cell to be written by using a thermally-assisted switching (TAS) write operation, includes a magnetic tunnel junction (MTJ) having a resistance that can be varied during a write operation when the MTJ is heated to a high threshold temperature, and a selected transistor electrically connected to the MTJ; a plurality of word lines and bit lines connecting MRAM cells along a row and a column, respectively; the method comprising supplying a bit line voltage to one of the bit lines and a word line voltage to one of the word lines for passing a heating current through the MTJ of a selected MRAM cell; once the MTJ has reached the high threshold temperature, varying the resistance of the MTJ; and cooling the MTJ to freeze said resistance in its written value; said word line voltage is a word line overload voltage which is higher than the base operating voltage of the MRAM cells such that the heating current has a magnitude that is high enough for heating the MTJ to the predetermined high threshold temperature.
EFFECT: reduced power consumption when writing in a memory device.
8 cl, 3 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to computer engineering. A magnetic element to be written using a thermally-assisted switching write operation comprises a magnetic tunnel junction formed from a tunnel barrier being disposed between first and second magnetic layers, said second magnetic layer having a second magnetisation the direction of which can be adjusted during a write operation when the magnetic tunnel junction is heated to a high threshold temperature; an upper current line connected at the upper end of the magnetic tunnel junction; and a strap portion extending laterally and connected to the bottom end of the magnetic tunnel junction; the magnetic element further comprising a bottom thermal insulating layer extending parallel to the strap portion and arranged such that the strap portion is between the magnetic tunnel junction and the bottom thermal insulating layer.
EFFECT: reduced heat loss in the magnetic tunnel junction.
14 cl, 7 dwg
FIELD: physics, computer engineering.
SUBSTANCE: present invention provides a magnetic memory element (1) which is suitable for a writing operation with thermal switching, comprising a current line (4) in electrical communication with one end of a magnetic tunnel junction (2), where the magnetic tunnel junction (2) comprises: a first ferromagnetic layer (21), having a fixed magnetisation; a second ferromagnetic layer (23) having magnetisation which can be freely set up with a given high temperature threshold; and a tunnelling barrier (22) which is provided between the first and second ferromagnetic layers (21, 23); where the current line (4) is adapted to transmit heating current (31) through the magnetic tunnel junction (2) during a write operation; where said magnetic tunnel junction (2) further comprises at least one heating element (25, 26) adapted to generate heat when heating current (31) passes through the magnetic tunnel junction (2); and a thermal barrier (30) in series with said at least one heating element (25, 26), where said thermal barrier (30) is adapted to limit heat generated by said at least one heating element (25, 26) within the magnetic tunnel junction (2).
EFFECT: producing a magnetic memory element (1) suitable for a write operation with thermal switching.
11 cl, 2 dwg
SUBSTANCE: magnetoresistive memory cell comprises a remagnetisable layer and a non-remagnetisable layer separated by a barrier layer, and writing and reading means. The memory cell further includes a fastening layer made of p- or n-type semiconductor material, the next layer of semiconductor material with an opposite type of conductivity, forming a p-n junction, comprises an address line and a bit line, situated on both sides of the listed layers of the memory cell, means of generating write currents in the address and bit lines, reading means in the form of means of measuring electrical resistance of the memory cell, as well as means of setting polarity and the value of relative electrical bias between the address and bit lines.
EFFECT: simple technique of making a magnetoresistive memory cell.
2 cl, 1 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to electronics, particularly to a method of recording and reading more than two bits of data for a magnetic random access memory (MRAM) cell. A MRAM cell comprises a magnetic tunnel junction formed from a read magnetic layer having a read magnetisation, and a storage layer comprising a first storage ferromagnetic layer having a first storage magnetisation, a second storage ferromagnetic layer having a second storage magnetisation. The method includes heating the magnetic tunnel junction over a high temperature threshold; orienting the first storage magnetisation at an angle relative to the second storage magnetisation for the magnetic tunnel junction to reach a resistance state level determined by the orientation of the first storage magnetisation relative to the orientation of the read magnetisation; and cooling the magnetic tunnel junction.
EFFECT: enabling storage of at least four distinct state levels in a MRAM cell using only one current line to generate a writing field.
15 cl, 14 dwg
FIELD: computer engineering.
SUBSTANCE: invention relates to computer engineering. Magnetic random access memory (MRAM) cell comprises a tunnel magnetic junction having the first ferromagnetic layer, the second ferromagnetic layer with the second magnetization, which can be oriented relative to the axis of anisotropy of the second ferromagnetic layer at a predetermined high-temperature threshold, and a tunnel barrier between the first and the second ferromagnetic layers; the first current transmission line extending along the first direction and being in communication with the tunnel magnetic junction; herewith the first current transmission line is configured able to provide the magnetic field to orient the second magnetization while transferring the field current; wherein the MRAM cell is configured relative to the first current transmission line in such a way, that while providing the magnetic field at least one magnetic field component is perpendicular to the said axis of anisotropy; the second ferromagnetic layer is of asymmetric shape along at least one of its dimensions, so that the second magnetization contains the pattern of C-shape condition.
EFFECT: technical result is the reduction of power consumption and improved dispersion of the switching field.
12 cl, 6 dwg