Preparation method of 4-inch low-dislocation indium antimonide < 211 > direction single crystal

Abstract

The invention relates to a 4-inch low-dislocation indium antimonide lt; 211gt, 211gt; the invention discloses a preparation method of directional single crystals and belongs to the technical field of photoelectric materials. According to the method, a Czochralski method is adopted to grow the single crystal, a resistance furnace is arranged on the periphery of an induction coil of a heating device, and by accurately controlling heating conditions, designing a proper temperature field in a growth chamber and further combining growth conditions such as the state of a solid-liquid interface, the pulling speed, the rotating speed and particularly the shoulder expanding angle in the crystal growth process, the single crystal is obtained. The longitudinal temperature gradient in the crystal growth process is reduced, and the dislocation density of the large-size indium antimonide single crystal with the diameter of 4 inches can be obviously reduced, so that indium antimonide is enabled to be lt; 211gt, 211gt; the dislocation density of the directional single crystal is less than 100 / cm < 2 >.

Description

Technical Field

[0001] The invention relates to a 4-inch low dislocation indium antimonide <211> The invention discloses a method for preparing a directional single crystal, and belongs to the technical field of optoelectronic materials. Background Art

[0002] InSb is the material with the narrowest bandgap and the highest mobility among III-V compound semiconductors. It has stable physical and chemical properties and is widely used in infrared detectors and Hall devices. The quantum efficiency of infrared detectors is closely related to the selected infrared sensitive materials. InSb has a very high quantum efficiency in the 3μm to 5μm band. InSb has the advantage of low cost in the preparation of infrared detectors. Therefore, InSb has broad prospects in the application of infrared detectors and has attracted more and more attention. In addition, in order to adapt to the trend of large-scale development of InSb infrared focal plane array devices, reduce the development cost of infrared detector devices and improve production efficiency, large-size InSb single crystal growth technology has been studied and developed at home and abroad.

[0003] At present, the growth of indium antimonide single crystals mainly adopts the Czochralski method, also known as the direct-pull single crystal technology, which is an important means of preparing semiconductor bulk single crystal materials. This method can grow crystals without being constrained by the crucible, and the outer dimensions of the crystals can be selected within a certain range. At the same time, the prepared crystals have high integrity. The equipment for growing single crystals by the Czochralski method mainly includes a heater, a quartz tube, a crucible, and a lifting rod. The heater heats the quartz tube area where the crucible is placed to melt the polycrystalline material inside the crucible. The seed crystal is inserted into the melt through the lifting rod, and then the seed crystal is slowly lifted. New crystals continue to grow under the seed crystal. During the growth of the single crystal, the quartz tube is filled with protective gas.

[0004] In the prior art, the growth of InSb single crystals is mainly achieved by doping with tellurium (Te) as an impurity to adjust the conductivity type and carrier concentration of the crystal. <211> and <111> , the heating method is medium frequency induction, and the single crystal growth atmosphere is a mixture of hydrogen and nitrogen. One disadvantage of the Czochralski method for growing indium antimonide single crystals is that there is a very high longitudinal temperature gradient in the furnace. Therefore, dislocations are easily generated during the crystal growth process. Especially when pulling single crystal ingots with a diameter of more than 20 mm, how to improve the integrity of the crystal and reduce the dislocation density remains a technical problem. Although there have been relevant studies in recent years on the integrity of indium antimonide crystals, especially on dislocations, there are few existing technologies that closely link the formation of dislocations with the growth process of indium antimonide single crystals.

[0005] Dislocation density is a major indicator of the quality of large-diameter InSb crystals. The amount of dislocation density directly reflects the quality. However, due to the low thermal conductivity, small stacking fault energy, and small critical shear stress of InSb, a large number of defects are easily generated due to heat fluctuations and stress. For the growth of large-sized InSb crystals, due to the increase in size and the increase in mass of InSb, it is difficult to control heat fluctuations and stress during the growth process, which leads to the easy generation of a large amount of dislocation density. Summary of the invention

[0006] In order to overcome the defects of the prior art, the present invention aims to provide a 4-inch low dislocation indium antimonide <211> The method for preparing single crystals in the direction of the sun is mainly to prepare large-sized and low-dislocation indium antimonide by precise temperature control. <211> Direction single crystal.

[0007] To achieve the purpose of the present invention, the following technical solutions are provided.

[0008] A 4-inch low dislocation indium antimonide <211> A method for preparing a directional single crystal, the method steps are as follows:

[0009] (1) placing high-purity indium antimonide polycrystals into a clean and dry quartz crucible, transferring the quartz crucible to a hydrogen-filled and sealed quartz tube, and heating the quartz tube area where the quartz crucible is placed, so that the high-purity indium antimonide polycrystal material in the quartz crucible is completely melted into liquid;

[0010] (2) Reduce the heating power, and after the crystal nuclei are formed on the surface of the liquid, use the lifting rod to <211> The indium antimonide seed crystal in the direction is inserted 5mm below the liquid surface. When the temperature difference between the liquid surface and the air above the liquid surface is 110℃~130℃, the seed crystal is pulled up at a speed of 18r / min and an ascending speed of 55mm / h. At the same time, the quartz crucible is rotated at a speed of 12r / min to form a shoulder section with a shoulder angle of 30°~35°, and a convex growth is adopted; then the heating power is uniformly reduced to form a large-sized equal-diameter section with a diameter of 4 inches, i.e. 10.16 cm; finally, the heating power is increased to form a tapered tail section with a gradually decreasing diameter, and a 4-inch low dislocation indium antimonide is obtained. <211> Direction single crystal;

[0011] The method adopts the Czochralski method to grow single crystals. A resistance furnace is arranged outside the induction coil of the heating device. The inner and outer diameters of the resistance furnace are the same as those of the induction coil, and the length is greater than the length of the pulled crystal. The inner ring of the resistance furnace is a porcelain tube, and the inner diameter of the porcelain tube is the same as the inner diameter of the induction coil. The outside of the porcelain tube is wound with furnace wire, and the outside of the furnace wire is wrapped with insulation material. The resistance furnace can effectively reduce the longitudinal temperature gradient during the growth of indium antimonide and reduce heat fluctuations.

[0012] The internal temperature of the resistance furnace is preferably maintained at 300°C.

[0013] Beneficial Effects

[0014] (1) The present invention provides a 4-inch low dislocation indium antimonide <211> A method for preparing a single crystal in the direction of the direction, the method can significantly reduce the dislocation density of a large-size indium antimonide single crystal with a diameter of 4 inches, so that the indium antimonide <211> The dislocation density of the single crystal is less than 100 / cm 2 .

[0015] (2) The present invention provides a 4-inch low dislocation indium antimonide <211> A method for preparing a directional single crystal, wherein the method adopts the Czochralski method to grow the single crystal, a resistance furnace is arranged outside the induction coil of a heating device, the heating conditions are precisely controlled, an appropriate temperature field in the growth chamber is designed, the longitudinal temperature gradient during the crystal growth process is reduced, thereby reducing the dislocation of the crystal, and achieving the pulling out of a single crystal with a large diameter and low dislocation.

[0016] (3) The present invention provides a 4-inch low dislocation indium antimonide <211> The method for preparing a single crystal in a directional direction, based on the control of heating conditions, further combines the state of the solid-liquid interface during the crystal growth process and the pulling speed, rotation speed, especially the shoulder expansion angle and other growth conditions, to achieve the preparation of a 4-inch large-size low-dislocation indium antimonide <211> Directed single crystal, making large size InSb with a diameter of 4 inches <211> The dislocation density of the single crystal is less than 100 / cm 2 . DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with specific embodiments, but is not intended to limit the present invention.

[0018] Comparative Example 1

[0019] A 4-inch indium antimonide <211> A method for preparing a directional single crystal, the method steps are as follows:

[0020] (1) placing high-purity indium antimonide polycrystals into a clean and dry quartz crucible, transferring the quartz crucible to a hydrogen-filled and sealed quartz tube, and heating the quartz tube area where the quartz crucible is placed, so that the high-purity indium antimonide polycrystal material in the quartz crucible is completely melted into liquid;

[0021] (2) Reduce the heating power, and after the crystal nuclei are formed on the surface of the liquid, use the lifting rod to <211> The indium antimonide seed crystal in the direction is inserted 5mm below the liquid surface. When the temperature difference between the liquid surface and the air above the liquid surface is 110℃, the seed crystal is pulled up at a speed of 18r / min and a rising speed of 55mm / h. At the same time, the quartz crucible is rotated at a speed of 12r / min to form a shoulder section with a shoulder angle of 30°, adopting a convex growth; then the heating power is uniformly reduced to form an equal-diameter section with a diameter of 4 inches; finally, the heating power is increased to form a tapered ending section with a gradually decreasing diameter, thus obtaining a 4-inch indium antimonide single crystal.

[0022] The prepared 4-inch InSb single crystal was sliced ​​and the 2θ of the slice was measured to be 76°15', indicating that the prepared 4-inch InSb single crystal is <211> Directional single crystal. The prepared 4-inch indium antimonide single crystal was sliced ​​into equal diameter sections, and the equal diameter sections were etched with CP4 etchant, and then observed under an optical microscope and statistically obtained that the dislocation density was 1000 / cm 2 , the dislocation is higher.

[0023] Example 1

[0024] A 4-inch low dislocation indium antimonide <211> A method for preparing a directional single crystal, the method steps are as follows:

[0025] (1) placing high-purity indium antimonide polycrystals into a clean and dry quartz crucible, transferring the quartz crucible to a hydrogen-filled and sealed quartz tube, and heating the quartz tube area where the quartz crucible is placed, so that the high-purity indium antimonide polycrystal material in the quartz crucible is completely melted into liquid;

[0026] (2) Reduce the heating power, and after the crystal nuclei are formed on the surface of the liquid, use the lifting rod to <211> The indium antimonide seed crystal in the direction of the liquid is inserted 5mm below the liquid surface. When the temperature difference between the liquid surface and the air above the liquid surface is 110°C, the seed crystal is pulled up at a speed of 18r / min and a rising speed of 55mm / h. At the same time, the quartz crucible is rotated at a speed of 12r / min to form a shoulder section with a shoulder angle of 30°, and a convex growth is adopted; then the heating power is uniformly reduced to form an equal diameter section with a diameter of 4 inches; finally, the heating power is increased to form a tapered tail section with a gradually decreasing diameter, and a 4-inch indium antimonide single crystal is prepared;

[0027] The method adopts the Czochralski method to grow a single crystal, and a resistance furnace is arranged outside the induction coil of the heating device, and the inner and outer diameters of the resistance furnace are the same as those of the induction coil, and the length is greater than the length of the pulled crystal; the inner ring of the resistance furnace is a porcelain tube, and the inner diameter of the porcelain tube is the same as the inner diameter of the induction coil, and the outside of the porcelain tube is wound with furnace wire, and the outside of the furnace wire is wrapped with insulation material. The resistance furnace can effectively reduce the longitudinal temperature gradient during the growth of indium antimonide and reduce heat fluctuations; the internal temperature of the resistance furnace is maintained at 300°C.

[0028] A 4-inch InSb single crystal prepared was sliced ​​and the 2θ of the slice was measured to be 76°15', indicating that the prepared 4-inch InSb single crystal is <211> Directional single crystal. The prepared 4-inch indium antimonide single crystal was sliced ​​into equal diameter sections, and the equal diameter sections were etched with CP4 etchant, and then observed under an optical microscope and statistically obtained that the dislocation density was 100 / cm 2 , indicating that a 4-inch low dislocation indium antimonide was prepared <211> Direction single crystal.

[0029] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A 4-inch low dislocation indium antimonide <211> A method for preparing a directional single crystal, characterized in that: (1) placing high-purity indium antimonide polycrystals into a clean and dry quartz crucible, transferring the quartz crucible to a hydrogen-filled and sealed quartz tube, and heating the quartz tube area where the quartz crucible is placed, so that the high-purity indium antimonide polycrystal material in the quartz crucible is completely melted into liquid; (2) Reduce the heating power, and after the crystal nuclei are formed on the surface of the liquid, use the lifting rod to <211> The indium antimonide seed crystal with a direction of 10°C is inserted below the liquid surface. When the temperature difference between the liquid surface and the air above the liquid surface is 110°C to 130°C, the seed crystal is pulled up at a speed of 18r / min and a rising speed of 55mm / h. At the same time, the quartz crucible is rotated at a speed of 12r / min to form a shoulder section with a shoulder angle of 30° to 35°, and a convex growth is adopted; then the heating power is uniformly reduced to form an equal diameter section with a diameter of 4 inches; finally, the heating power is increased to form a tapered tail section with a gradually decreasing diameter, and a 4-inch low dislocation indium antimonide is obtained. <211> Direction single crystal; The method adopts the Czochralski method to grow single crystals, and a resistance furnace is arranged outside the induction coil of a heating device.

2. A 4-inch low dislocation indium antimonide according to claim 1 <211> A method for preparing a directional single crystal, characterized in that: The inner and outer diameters of the resistance furnace are the same as those of the induction coil of the heating device, and the length is greater than the length of the pulled crystal; the inner ring of the resistance furnace is a porcelain tube, the inner diameter of the porcelain tube is the same as the inner diameter of the induction coil, the outside of the porcelain tube is wound with furnace wire, and the outside of the furnace wire is wrapped with insulation material.

3. A 4-inch low dislocation indium antimonide according to claim 1 or 2 <211> A method for preparing a directional single crystal, characterized in that: The internal temperature of the resistance furnace was maintained at 300°C.

4. A 4-inch low dislocation indium antimonide according to claim 1 or 2 <211> A method for preparing a directional single crystal, characterized in that: Will <211> The indium antimonide seed crystal is inserted 5 mm below the liquid surface.

5. A 4-inch low dislocation indium antimonide according to claim 1 or 2 <211> A method for preparing a directional single crystal, characterized in that: The internal temperature of the resistance furnace is maintained at 300°C; <211> The indium antimonide seed crystal is inserted 5 mm below the liquid surface.