CN-121992491-A - Device and method for growing nitride crystal by regulating temperature gradient

CN121992491ACN 121992491 ACN121992491 ACN 121992491ACN-121992491-A

Abstract

The invention provides a device and a method for growing nitride crystals by regulating temperature gradient, which belong to the technical field of semiconductor synthesis and comprise a low-temperature reaction zone and a high-temperature crystallization zone, wherein the outer sides of the low-temperature reaction zone and the high-temperature crystallization zone are provided with heaters, a temperature field is constructed in the high-temperature crystallization zone, the low-temperature reaction zone is provided with a first air inlet pipe, a second air inlet pipe and a reaction boat, the tail end of the first air inlet pipe is communicated with the reaction boat, the tail end of the second air inlet pipe is communicated with the high-temperature crystallization zone, the high-temperature crystallization zone is provided with a seed crystal fixing support, and the seed crystal fixing support is fixedly arranged on a seed crystal fixing rod. The temperature field with the temperature gradient is constructed by adjusting the structure of the inner cavity of the high-temperature crystallization area or adjusting the arrangement mode of the heaters at the outer side of the high-temperature crystallization area, the repeatability is good, the growth efficiency of the nitride body block crystal is improved by controlling the axial temperature gradient and the radial temperature gradient, and the growth quality is ensured.

Inventors

YU RUIXIAN
XIA WEI
ZHAO GANG
JIANG KAI
TANG WENJING
XU XIJIN

Assignees

济南大学

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (9)

1. The device for growing nitride crystals by regulating temperature gradients is characterized by comprising a cavity (1), wherein the cavity (1) comprises a low-temperature reaction zone (2) and a high-temperature crystallization zone (3) which are sequentially connected, a plurality of heaters (8) used for heating are arranged on the outer sides of the low-temperature reaction zone (2) and the high-temperature crystallization zone (3), a temperature field with an axial temperature gradient and a radial temperature gradient is constructed in the high-temperature crystallization zone (3), a first air inlet pipe (5) used for introducing hydrogen chloride gas or chlorine gas, a second air inlet pipe (7) used for introducing ammonia gas and a reaction boat (4) are arranged in the low-temperature reaction zone (2), the tail end of the first air inlet pipe (5) is communicated with the reaction boat (4), the tail end of the second air inlet pipe (7) is communicated with the high-temperature crystallization zone (3) through an air outlet (10), hydrogen chloride gas in the first air inlet pipe (5) or chlorine gas reacts with metal in the reaction boat (4) to generate intermediate products, and the intermediate products are communicated with the high-temperature crystallization zone (3) through an intermediate pipeline (6); The high-temperature crystallization area (3) is provided with a seed crystal fixing support (11), the seed crystal fixing support (11) is fixedly arranged on a seed crystal fixing rod (12), ammonia gas in the second air inlet pipe (7) and intermediate products react at the position of the seed crystal fixing support (11) to generate nitride, and a region of 0-2cm range on the left side of the seed crystal fixing support (11) is a crystal growth region.
2. The device for growing nitride crystals by regulating the temperature gradient according to claim 1, characterized in that the gas outlet (10) comprises an ammonia gas outlet (101) and an intermediate product outlet, the ammonia gas outlet (101) being not in communication with the intermediate product outlet, the ammonia gas outlet (101) being in communication with the end of the second gas inlet pipe (7), the intermediate product outlet being in communication with the end of the intermediate pipe (6).
3. The device for growing nitride crystals by regulating temperature gradient according to claim 1, wherein the cavity (1) located in the high temperature crystallization zone (3) comprises a first pipe section (13), a second pipe section (14) and a third pipe section (15) which are sequentially connected, the shaft diameter of the second pipe section (14) is smaller than that of the first pipe section (13) and that of the third pipe section (15), the shaft diameter of one end of the first pipe section (13) close to the second pipe section (14) is gradually reduced, the shaft diameters of the second pipe section (14) are the same, and the shaft diameter of one end of the third pipe section (15) close to the second pipe section (14) is gradually reduced.
4. A device for growing nitride crystals by modulating the temperature gradient according to claim 3, characterized in that the seed crystal holding tray (11) is located at the second tube section (14) of the cavity (1) of the high temperature crystallization zone (3).
5. The apparatus for growing a nitride crystal by regulating a temperature gradient according to claim 1, wherein a spacing between the heaters (8) located on the left side of the seed crystal fixing mount (11) is smaller than a spacing between the heaters (8) located on the right side of the seed crystal fixing mount (11).
6. The apparatus for growing a nitride crystal by regulating a temperature gradient according to claim 3 or 5, wherein an axial temperature gradient of the crystal growth region temperature field is 0.5 to 10 ℃ per cm, and a radial temperature gradient of the crystal growth region temperature field is 0.5 to 2 ℃ per cm.
7. Device for growing nitride crystals by regulating the temperature gradient according to claim 1, characterized in that the outside of the heater (8) is provided with a heat-insulating layer (9) for heat preservation.
8. A method for growing a nitride crystal by regulating a temperature gradient, characterized in that the method uses the apparatus for growing a nitride crystal by regulating a temperature gradient according to any one of claims 1 to 7, comprising the steps of: s1, fixing seed crystals on a seed crystal fixing support (11) and placing the seed crystals in a high-temperature crystallization area (3) so that the distance between the seed crystals and an air outlet (10) is 1-10cm; s2, heating the low-temperature reaction zone (2) and the high-temperature crystallization zone (3) to required temperature, controlling the axial temperature gradient of a temperature field of a crystal growth zone to be 0.5-10 ℃ per cm, controlling the radial temperature gradient of the temperature field of the crystal growth zone to be 0.5-2 ℃ per cm, and continuously introducing carrier gas and ammonia gas in the heating process; S3, after the temperatures of the low-temperature reaction zone (2) and the high-temperature crystallization zone (3) are stable, starting to introduce hydrogen chloride gas, wherein the hydrogen chloride gas reacts with metal in the reaction boat (4) in the low-temperature reaction zone (2) to generate an intermediate product, the intermediate product is transported to the high-temperature crystallization zone (3) through carrier gas, the intermediate product reacts with ammonia gas at a seed crystal fixing support (11) to generate nitride, and the nitride growth time is at least 50h; And S4, stopping introducing hydrogen chloride gas after the nitride grows, starting cooling the high-temperature crystallization zone (3), stopping introducing ammonia gas when the temperature is reduced to the stable temperature of the low-temperature reaction zone (2), and taking out the grown nitride after the low-temperature reaction zone (2) and the high-temperature crystallization zone (3) are cooled to room temperature.
9. The method for growing a nitride crystal by regulating a temperature gradient according to claim 8, wherein the carrier gas is at least one of N2, H2, and Ar.

Description

Device and method for growing nitride crystal by regulating temperature gradient Technical Field The invention relates to the technical field of semiconductor synthesis, in particular to a device and a method for growing nitride crystals by regulating and controlling temperature gradients. Background The nitride crystal belongs to a third-generation semiconductor material, has the characteristics of large forbidden bandwidth, large heat conductivity, high breakdown electric field, small dielectric constant, high electron saturation drift speed, better chemical stability, strong radiation resistance and the like, and has great application potential in the aspects of light emitting devices such as blue light diodes, blue light lasers, ultraviolet detectors and the like and high-temperature, high-frequency and high-power microelectronic devices. The hydride epitaxial growth method (HVPE) is the mainstream growth technology for preparing nitride crystals at present, does not need the growth conditions of ultrahigh temperature and ultrahigh pressure, has low requirements on production equipment, and has the advantages of high growth speed, easy realization of doping and the like. The basic principle of growing nitride crystal by HVPE method is that metal source reacts with hydrogen chloride gas in low temperature reaction zone to generate metal chloride, then the metal chloride is transported to high temperature crystallization zone by high purity nitrogen gas to react with ammonia gas, and the nitride crystal is deposited on seed crystal. The growth of nitride bulk crystal needs a certain temperature gradient, while the low-temperature reaction area and the high-temperature crystallization area of most of the current HVPE reactors are constant-temperature areas, and in addition, the HVPE reactors realize the temperature gradient of the high-temperature crystallization area by using induction heating, but the repeatability is poor, when the nitride bulk crystal is grown, the growth efficiency is low, and the crystal quality cannot be ensured. Therefore, we propose an apparatus and method for growing nitride crystals by modulating the temperature gradient. Disclosure of Invention The present invention is directed to an apparatus and a method for growing nitride crystal by controlling a temperature gradient, which solve the above-mentioned problems of the prior art. In order to achieve the above purpose, the present invention adopts the following technical scheme: In a first aspect, the invention provides a device for growing nitride crystals by regulating temperature gradients, which comprises a cavity, wherein the cavity comprises a low-temperature reaction zone and a high-temperature crystallization zone which are sequentially connected, a plurality of heaters used for heating are arranged on the outer sides of the low-temperature reaction zone and the high-temperature crystallization zone, a temperature field with an axial temperature gradient and a radial temperature gradient is constructed in the high-temperature crystallization zone, a first air inlet pipe used for introducing hydrogen chloride gas or chlorine gas, a second air inlet pipe used for introducing ammonia gas and a reaction boat are arranged in the low-temperature reaction zone, the tail end of the first air inlet pipe is communicated with the reaction boat, the tail end of the second air inlet pipe is communicated with the high-temperature crystallization zone through an air outlet, hydrogen chloride gas or chlorine gas in the first air inlet pipe reacts with metal in the reaction boat to generate an intermediate product, and the intermediate product is communicated with the high-temperature crystallization zone through an intermediate pipeline; The high-temperature crystallization area is provided with a seed crystal fixing support, the seed crystal fixing support is fixedly arranged on a seed crystal fixing rod, ammonia gas in the second air pipe and an intermediate product react at the position of the seed crystal fixing support to generate nitride, and the area of the left side of the seed crystal fixing support within the range of 0-2cm is a crystal growth area. Preferably, the air outlet comprises an ammonia air outlet and an intermediate product air outlet, the ammonia air outlet is not communicated with the intermediate product air outlet, the ammonia air outlet is communicated with the tail end of the second air inlet pipe, and the intermediate product air outlet is communicated with the tail end of the intermediate pipeline. Preferably, the cavity located in the high temperature crystallization area comprises a first pipe section, a second pipe section and a third pipe section which are connected in sequence, the shaft diameter of the second pipe section is smaller than that of the first pipe section and that of the third pipe section, the shaft diameter of one end of the first pipe section, which is close to the second pipe section,