The method of growing silicon single crystals
(57) Abstract:The purpose of the invention is the control of oxygen concentration (obtaining a given value of Nabout) dislocation single crystal silicon grown by the Czochralski method. This objective is achieved in that in the method of growing silicon single crystals by Choralschola using installed inside the heater quartz crucible with a diameter of 300 30 mm with respect to the surface area of contact of the melt with the crucible to the area of surface contact of the melt of 1.5 - 4.0 distance (h) from the initial level of the melt in the crucible to the top of the heater support equal to 2 to 9 cm, and the increase (decrease) in the concentration of oxygen in the upper part of growing a single crystal on each of 0.4 0,21017cm-3spend by increasing (decreasing) the level of the melt 1 cm within the interval h. The proposed solution allows to grow silicon single crystals for a broad class of semiconductor devices with different requirements to the oxygen concentration. 1 Il., table 1. The invention relates to the technology of semiconductor materials, in particular to the technology of growing silicon by the Czochralski method. Monocrystal and power semiconductor technology.Czochralski method includes the single crystal growth on a monocrystalline seed crystal from a melt of silicon, placed in a quartz crucible. As a result of the interaction of the melt with the walls of the quartz crucible of the growing crystal is enriched with oxygen. The level of oxygen concentration in the Si crystals depending on the type of semiconductor devices and specific technologies of their production should be quite different. So, in the manufacture of integrated circuits (especially VLSI) oxygen concentration (Nabout) must be high enough to effect internal gettering. In silicon, suitable for the production of powerful transistors and devices power semiconductor technology, Naboutthe contrary should be the minimum possible to ensure high thermal stability electrophysical and structural properties of silicon. In connection with the foregoing, a need arises for the development of technological methods management (obtaining a given value of) the oxygen concentration in the grown silicon single crystals.A method of obtaining single-crystal Si with low oxygen content  according to which in rspl is provided in the crystal lattice of the grown silicon oxygen with the formation of new compounds. In the example in  for example, with the addition of a Si melt Germany in the amount of 6% by weight of Noin the crystals is reduced by almost 2 times. The disadvantages proposed in  of this method include the possibility of a violation dislocation growth or occurrence of some other structural defects associated with the input impurities, especially for growing single crystals of Si large diameter and of great length.A method of obtaining single-crystal Si c increased oxygen  whereby to prevent evaporation of SiO (and therefore, increasing Noin the growing crystal) on the outside surface of the melt is rotating quartz ring with an inner diameter greater than 1.2 times the diameter of the growing crystal.The disadvantages described in  method is the difficulty of ensuring dislocation of crystal growth due to the proximity of the foreign body, as well as some of the problems associated with obtaining good shape as-grown crystals due to the complexity of automatic maintenance of the diameter.A common shortcoming described in  and  methods is the fact one-sided impact on the oxygen concentration, i.e. it ASS="ptx2">A known method of controlling the oxygen concentration in the grown by the Czochralski single crystals of Si by changing factors that affect the hydrodynamics of the flow in the melt Si frequency of rotation of the crystal (Wkr) and the crucible (Wtand Wkr/Wt Thus, in accordance with  the oxygen concentration in the upper part of the Si single crystals with a diameter of 75 to 80 mm, grown under conditions of Wkr20 rpm and Wt2 rpm, was more than 1.5 times higher than in the conditions of Wkr0,5 rpm and Wt15 rpm, however, described in  the method merely States the fact of the influence of Wt, Wkrand Wkr/Wtbut does not give the necessary guidance oxygen concentration in the desired range of values of Nabout.The closest solution adopted for the prototype, a method described in  was Proposed in  the method allows to control the oxygen concentration in the upper parts (in place out on the constant diameter) of single crystals of Si in a fairly wide range by selecting the corresponding relationship of the surface area of contact of the melt with the crucible (Sto) to the area of the open surface of the melt (Sandin the range of 1.5 to 4.0 and the subsequent formulation of owenia melt. So, to obtain the Naboutin the upper part of the Si single crystals with a diameter of 80 mm at the level of 1,21018cm-3( 9,01017cm-3when the calibration coefficient 2,451017cm-2) you must implement the relation Sto/Sand2,8 by using, for example, the crucible with a diameter of 270 mm and loaded into the crucible 16 kg (the recommended value of Wkrand Wtto ensure the specified value of Naboutin  are not given).However, in  examined the influence of factors determining the wall temperature of the quartz crucible, namely the design of the shielding thermal unit and the position of the melt within a hot zone setup cultivation. However, it is known that the temperature of the crucible wall leads to a significant change in the dissolution rate of the quartz crucible into the melt of Si, and therefore, to change the number of admissions in the melt (and crystal) oxygen, even when the equal treatment Sto/Sand.The purpose of the invention, the control of oxygen concentration (obtaining a given value of Nabout) dislocation Si single crystals grown by the Czochralski method.This objective is achieved in that in the method virusiv is Igla diameter 300 30 mm with respect to the surface area of contact of the melt with the crucible to the area of the open surface of the melt of 1.5-4.0 distance (h) from the initial level of the melt in the crucible to the top of the heater support equal to 2 9 cm, and increase (decrease) in the concentration of oxygen in the upper part of growing a single crystal on every 0,4 0,21017cm-3spend by increasing (decreasing) the level of the melt 1 cm within the specified interval h.Selects the specified interval of values of h because h is less than 2 cm and more than 9 cm is extremely difficult dislocation growth of the crystal. In addition, when h > 9 cm due to low radial temperature gradient in the melt difficulties with ensuring good shape of the growing crystal. To overcome this limitation would require the application of extremely low speeds cultivation that is not economically feasible.On the other hand, when grown under conditions of h < 2 cm increases the likelihood of spontaneous crystallization of the melt at the walls of the quartz crucible (the so-called "Pomorski").The change in oxygen concentration in the crystal when changing the initial position of the melt 1 cm is in the range (0,2-0,6)1017cm-3and is determined by the type of installation: growing by design its thermal unit), as well as the size, shape and material of the elements under the crucible and heat shielding node. Thus, in particular, the experience is) leads to an increase in No/h more than 1.5 times. In the fluctuation value of No/h 0,21017cm-3/cm also includes the error of the method of measuring the concentration of oxygen.The drawing shows the basic elements of thermal unit of the cultivation, as well as claimed in the invention the parameter h. In the drawing, the following notation: 1 graphite heater; 2 quartz crucible; 3 - Si melt; 4 cylindrical graphite element under the crucible.Example. The Si single crystals with a diameter of 80, 105 and 155 mm brand KDB 12 crystallographic orientation of <100> were grown in the "Subject-30" in the flow of argon from the crucible with a diameter of 330 mm Cylindrical element under the crucible (item 4 in the drawing) was made in the form of graphite grid. The gas flow was: when growing a single crystal with a diameter of 80 mm 800 l/h, with a diameter of 105 mm 1200 l/h and a diameter of 155 mm 1500 l/h the Rate of cultivation has changed from 1.5 to 0.5 mm/min according to the program. Rotation frequency of the crystal and the crucible was maintained constant, respectively, 20 and 3.minutesThe growing crystal was carried out at different initial position of the melt level in the crucible relative to the heater, for which the crucible was moved by the specified distance.The concentration to which the communication on the wavelength of 9.1 μm when using the calibration coefficient 2,451017cm-2.The table lists some additional data on the mode of growing single crystals: mass loading in the crucible, the ratio of Sto/Sandthe value of h, and the results of measurement of Naboutin crystals and value of No/h.
As can be seen from the presented data, in a tested embodiment, thermal design of the site and relationship Sto/Sandby changing the initial position of the melt relative to the heater, it is possible to control the oxygen concentration in the upper parts of the Si single crystals in a fairly wide range: (5-8,5)1017cm-3for crystals with a diameter of 80 mm (5,7 - 9,3)1017cm-3for crystals with a diameter of 105 mm and (7-11)1017cm-3for crystals with a diameter of 155 mmThus, the proposed solution allows to grow single crystals of Si for a broad class of semiconductor devices with different requirements for values of Nabout. Thus, the Si single crystals with a diameter of 80 mm with Nabout51017cm-3, grown in accordance with example 3 of the table can be used in the production of power transistors, where the necessary condition is extremely high thermal stability of the electrical resistivity Si.Data presented in table are also convincing demonstration of the main disadvantage of the method of growing the prototype  the crystal growing at the same value of Sto/Sandbut at different position of the melt inside the heat unit of the cultivation, leads to significantly different values of Naboutin crystals. So, for example, single crystals with a diameter of 80 mm, grown in the conditions of implementation of the same relationship Sto/Sand(1,8), but when changing h in the range of 2 to 9 cm, size of Naboutchange within (5-8,5)1017cm-3.Thus, specified in the application to growing conditions are optimal and expedient from the point of view of achieving the desired positive effect control the oxygen concentration of the dislocation single crystal Si in a wide interval of values. Such crystals can be successfully used in devices of the power semiconductor and electronic equipment. The method of growing silicon single crystals by Choralschola using fixed inside the area of the open surface of the melt 1,5 4,0, characterized in that the distance h from the initial melt level in the crucible to the top of the heater support equal to 2 to 9 cm, and the increase (decrease) in the concentration of oxygen in the upper part of a growing crystal for every (0,4 0,2) 1017cm-3spend by increasing (decreasing) the level of the melt 1 cm within the specified interval h.
FIELD: crystal growth.
SUBSTANCE: method comprises crystal growing in two stages: growing alloyed crystals used for making blanks of seeds made of a disk of a given diameter and approximately 5-6-mm thick and subsequent growing of nominally pure crystals.
EFFECT: enhanced quality of crystals.
FIELD: production of solar batteries, integrated circuits and other semiconducting devices.
SUBSTANCE: the invention presents a method of production of alloyed monocrystals or polycrystals of silicon and may be used in production of solar batteries, integrated circuits and other semiconductor devices. The substance of the invention: the method of SUBSTANCE: the invention presents a method of production of alloyed monocrystals or polycrystals of silicon includes preparation of the initial charge consisting of 50 % of silicon alloyed with phosphorus with a specific electrical resistance of 0.8-3.0 Ohm·cm or boron with specific electrical resistance of 1-7 Ohm·cm, its melting-down and consequent growing of crystals from the melt, in which additionally enter elements of IV group from the periodic table by Mendeleyev, in the capacity of which use germanium, titanium, zirconium or hafnium use in concentrations of 1017-7·1019 cm-3. The invention allows to produce chips with high values of life time of minority carrier (LTMC), high homogeneity of electric resistivity (ER) and high concentration of oxygen, with a low concentration of defects and increased thermostability and radiation resistance.
EFFECT: the invention ensures production of chips with high values of LTMC, high homogeneity of ER and high concentration of oxygen, with a low concentration of defects and increased thermostability and radiation resistance.
2 cl, 4 ex, 1 tbl
FIELD: crystal growing technologies.
SUBSTANCE: invention relates to technology of growing crystals for passive laser shutters used in modern lasers operated in IR spectrum region. Crystals are grown according to Chokhralsky method from initial stock melt containing metal oxide mixture, namely produced via solid-phase synthesis gallium-scandium-gadolinium garnet of congruently melting composition with magnesium and chromium oxide additives assuring concentration of chromium and magnesium cations in melt 2.0·1020 to 2.6·1020 at/cm3. Process is carried out at cell pressure 1.4 atm in argon and carbon dioxide medium with carbon dioxide content 14-17% by volume. Invention makes it possible to grow perfect crystals of gallium-scandium-gadolinium garnets alloyed with chromium cations, which are characterized by absorption coefficient above 5 cm-1 within wavelength 1.057-1.067 μm generation range.
EFFECT: achieved required Q-switching mode in continuous and pulsed operation conditions.
FIELD: chemistry; passive Q-switch crystal growing process.
SUBSTANCE: production process for growing crystals of galium scandium gadolinium garnets is based on Czochralski process, which implies crystal growing from initial molten batch, which is congruently melting gallium scandium gadolinium garnet produced by 3-phase synthesis, doped with magnesium oxide and chromium oxide. These oxides provide for 2.0×1020-2.6×1020 atoms/cm3 concentration of cromium and magensium cations in melt during the first crystal growing, in argon with 14-17% of carbon dioxide, pressure in chamber being 1.3-2.0 atm. For the second, third and subsequent growths, an initial batch amount equal to previous crystal weight, cromium and magnesium content in batch being determined according to formula (СCr×СMg)/1020 = 0.5÷2, where СCr is at least 5×1019 atoms/cm3, is added to the crucible.
EFFECT: provides for required Q-switched mode, continuous or pulse, within wavelength range of 1,057-1,067 mcm.
FIELD: technological process.
SUBSTANCE: invention is related to growing of garnets single crystals and may be used in laser equipment, magnet microelectronics (semi-conductors, ferroelectrics) and for jewelry purposes. Single crystals of terbium-gallium garnet are prepared by Chochralski method by means of melting primary stock, which includes clarifying calcium-containing additive, and further growing of single crystal from melt to primer. As primary stock mixture of terbium and gallium oxides is used, as calcium containing additive - calcium oxide or carbonate, and after growing crystal is annealed in atmosphere of hydrogen at temperature of 850-950°C for around 5 hours until orange paint disappears.
EFFECT: allows to prepare optically transparent homogeneous crystals.
SUBSTANCE: invention relates to the technology of growing monocrystals using Chokhralsky method. Growth of doped crystals of lithium niobate with composition close to stoichiometric is done on an inoculating crystal from molten mixture of lithium niobate of identical composition with ratio Li/Nb equal to 0.938-0.946 and containing 9-13 mol % K2O and 0.5-2.5 mol % MgO or ZnO, in conditions of applied electric field with current density of 0.2-40 A/m2. A device is provided for realising the method, comprising a housing with a growth station and a cooling chamber, crucible 1, placed in the growth station, induction heater, top metallic heating shield 4, fitted above the crucible 1, mechanism for moving the crystal with a coupling rod, a rod with a holder 3 for the inoculating crystal 2. The device is also provided with a regulated direct current source 10 with electrodes; under the inoculating crystal 2 there is an additional load from electrically conducting material, separated from the wall of the holder by electrically insulating material. One of the electrodes is connected to the crucible 1, and the second - to the load.
EFFECT: invention allows for growing large optically homogenous crystals of lithium niobate with composition close to stoichiometric Li/Nb>0,994, additionally doped with MgO or ZnO, composition of which in the top and bottom parts of the crystal is virtually the same, without destroying the inoculating crystal.
5 cl, 2 ex, 2 dwg
SUBSTANCE: invention relates to production of silicon monocrystals by Czochralski method or silicon multicrystals by method of directed crystallisation to be used in making solar cells and modules with higher operating performances. Proposed method comprises preparing initial mix alloyed with boron and its melting. Note here that aluminium is added to produced melt in amount sufficient for allow ratio between concentrations of aluminium and oxygen equal to 1-102.
EFFECT: p-type conductance silicon with low concentration of oxygen.
FIELD: physics, optics.
SUBSTANCE: invention relates to the technology of producing a terbium aluminium garnet single crystal which can be used as a polarisation rotator (Faraday rotator) in optics. The single crystal is a terbium aluminium garnet single crystal in which part of the aluminium is replaced with lutetium (Lu) and which has the following chemical formula:
EFFECT: invention increases the size of obtained crystals.
10 cl, 9 dwg, 4 ex
SUBSTANCE: invention relates to production of semiconductor materials and specifically to production of gallium antimonide monocrystals, which are used as substrate material in isoperiodic heterostructures based on ternary or quaternary solid solutions in Al-Ga-As-Sb and In-Ga-As-Sb systems, which enable to produce a wide range of optoelectronic devices (radiation sources and detectors in the 1.3-2.5 mcm spectral range). The method includes synthesis and growing a monocrystal using a Chochralski method in a hydrogen atmosphere on a seed crystal in the  crystallographic direction, wherein synthesis of the monocrystal is carried out in a single process with the flow rate of especially pure hydrogen in the range of 80-100 l/h and holding the melt at the synthesis step at 930-940°C for 35-40 minutes.
EFFECT: invention enables to obtain perfect large-size gallium antimonide monocrystals with diameter of 60-65 mm.
SUBSTANCE: invention relates to field of obtaining semi-conductor materials, which are applied as substrate material in isoperiod heterostructures based on triple and fourfold solid solutions in systems Al-Ga-As-Sb and In-Ga-As-Sb, which make it possible to create broad range of optoelectronic devices (sources and receivers of irradiation on spectral range 1.3-2.5 mcm). Method includes synthesis from initial components and growing of monocrystals by method of Czochralski in hydrogen atmosphere on seed, oriented in crystallographic direction . To initial components added is isovalent admixture of indium in form of especially pure indium antimonide (InSb) in the interval of elementary indium concentration (2-4)×1018 at/cm3, with synthesis and growing of monocrystals being realised in single technological cycle.
EFFECT: invention makes it possible to obtain big-volume low dislocation density monocrystals of gallium antimonide with reduced dislocation density.
2 cl, 1 dwg, 2 tbl, 1 ex