CN-120797184-B - Silicon carbide crystal growth device and growth method

CN120797184BCN 120797184 BCN120797184 BCN 120797184BCN-120797184-B

Abstract

The application provides a silicon carbide crystal growth device and a silicon carbide crystal growth method, belongs to the technical field of silicon carbide crystal growth, and solves the problem that the quantity of crystal expanding growth atmosphere is difficult to control in the prior art. The application comprises a crucible, an expanding ring, a partition component and a heating component, wherein the expanding ring is arranged at the peripheral side of a seed crystal fixing area, the expanding ring is provided with an inclined surface, the partition component comprises a separating ring and a cover body, the separating ring is arranged at the bottom of the crucible and is opposite to the seed crystal fixing area, the peripheral side of the separating ring is opposite to the inclined surface, the peripheral side of the separating ring is used for arranging a first raw material, the cover body is connected to the separating ring and is detachably connected, the cover body is made of graphite or polycrystalline silicon carbide, the thickness of the cover body is less than or equal to 0.5mm, the cover body and the separating ring are enclosed to form a containing cavity, and the containing cavity is used for arranging a second raw material. The application can stably expand the diameter and simultaneously ensure the quality of the crystal, simultaneously reduce the temperature gradient of a crystal growth interface and improve the uniformity of the resistivity of the crystal after expanding the diameter.

Inventors

HU JIANRONG
OUYANG PENGGEN
ZHANG ZHIWEI
WANG CHUANYONG
Qiao Fa
HUANG JUN

Assignees

内蒙古晶环电子材料有限公司
宁夏创盛新材料科技有限公司
浙江晶瑞电子材料有限公司

Dates

Publication Date: 20260512
Application Date: 20250912

Claims (10)

1. A silicon carbide crystal growth apparatus, comprising: The crucible (100), the top of the crucible (100) is provided with a seed crystal fixing area (Q), and the seed crystal fixing area (Q) is used for fixing seed crystals; An expanding ring (200), wherein the expanding ring (200) is arranged on the outer periphery side of the seed crystal fixing area (Q), the expanding ring (200) is provided with an inclined surface (210), and the inclined surface (210) extends towards the direction deviating from the seed crystal fixing area (Q); -a partition assembly (300), the partition assembly (300) comprising: The separation ring (310) is arranged at the bottom of the crucible (100) and is opposite to the seed crystal fixing area (Q), the outer circumferential side of the separation ring (310) is opposite to the inclined surface (210), and the outer circumferential side of the separation ring (310) is used for setting a first raw material; The cover body (320), the cover body (320) is connected to the separation ring (310) and is detachably connected, the cover body (320) is made of graphite or polycrystalline silicon carbide, the thickness of the cover body (320) is less than or equal to 0.5mm, the cover body (320) and the separation ring (310) are enclosed to form a containing cavity (330), the containing cavity (330) is internally used for setting a second raw material, and A heating assembly (400), the heating assembly (400) comprising: a first heater (410), wherein the first heater (410) is arranged below the crucible (100) and acts on the outer peripheral side of the separation ring (310); and a second heater (420), wherein the second heater (420) is arranged on the inner periphery of the first heater (410) and acts on the accommodating cavity (330).
2. The silicon carbide crystal growth apparatus of claim 1, wherein the housing (320) comprises: -a first portion (321), the first portion (321) being connected to the spacer ring (310), the first portion (321) having a thickness H 1 and an average distance D 1 from the first portion (321) to the inclined surface (210); A second portion (322), the second portion (322) being disposed on the first portion (321) and connected to the first portion (321), the second portion (322) having a thickness H 2 and a shortest distance of the second portion (322) to the inclined surface (210) being D 2 ; Wherein the H 2 ＜H 1 , and the D 2 ＜D 1 .
3. The silicon carbide crystal growth apparatus of claim 2, wherein said housing (320) further comprises a third portion (323), said third portion (323) disposed between said first portion (321) and said spacer ring (310), said third portion (323) having a thickness H 3 , said H 3 ＜H 1 ; A release structure (340) is formed between the spacer ring (310) and the third portion (323), and the release structure (340) allows the second portion (322) to have a vertical downward movement degree of freedom after the third portion (323) is decomposed.
4. A silicon carbide crystal growth apparatus according to claim 3, wherein the enclosure (320) has a first state and a second state; In the first state, the third portion (323) is solid to support the first portion (321) and the second portion (322), and a guide channel (S) is formed between the first portion (321), the second portion (322) and the inclined surface (210), and extends to the seed crystal fixing area (Q); In the second state, the third part (323) is decomposed and gasified, and the first part (321) and the second part (322) have a vertical downward movement degree of freedom so as to avoid crystals grown in the seed crystal fixing area (Q).
5. The silicon carbide crystal growth apparatus according to claim 2, wherein the first portion (321) is provided with a plurality of micropores (3211), the pore diameter of the micropores (3211) is less than or equal to 10 μm, and the porosity of the first portion (321) ranges from 5% to 10%.
6. The silicon carbide crystal growth apparatus of claim 1, wherein the cover (320) comprises a major material component that occupies greater than or equal to 99.995% of the overall material of the cover (320).
7. A silicon carbide crystal growth method applied to the silicon carbide crystal growth apparatus according to any one of claims 1 to 6, comprising the steps of: Preparing a first raw material, a second raw material and a cover body (320), connecting the cover body (320) to the separation ring (310) to form a containing cavity (330) in a surrounding manner, sealing the second raw material in the containing cavity (330), and placing the first raw material on the outer periphery side of the separation ring (310); Starting a first heater (410), controlling the temperature of the first heater (410) to be T 1 , and enabling the first raw material to sublimate and be conveyed to the surface of the seed crystal along the expanding inclined plane for deposition growth; And starting the second heater (420), and controlling the temperature of the second heater (420) to be T 2 ,T 2 -T 1 to be more than or equal to 80 ℃ so as to decompose the cover body (320) and trigger the second raw material to sublimate.
8. The method of growing a silicon carbide crystal according to claim 7, further comprising the step of controlling the first heater (410) to be started first and the second heater (420) to be started later, and controlling the ratio of the heating time of the first heater (410) to the heating time of the second heater (420) to be (3-5): 1.
9. The method of growing silicon carbide crystal according to claim 7, wherein the preparing the first raw material, the second raw material, and the cap (320) comprises: And installing the cover body (320), and controlling the minimum distance D between the installation position of the cover body (320) and the seed crystal fixing area (Q) to be more than or equal to 55mm.
10. The method of growing silicon carbide crystal according to claim 7, wherein the preparing the first raw material, the second raw material, and the cap (320) comprises: b 4 C is filled in the micropores (3211) of the cover body (320), and the filling amount of B 4 C is controlled , wherein, The porosity of the micropores, V is the volume of the cover (320), and ρ is the density of B 4 C.

Description

Silicon carbide crystal growth device and growth method Technical Field The application belongs to the technical field of silicon carbide crystal growth, and particularly relates to a silicon carbide crystal growth device and a silicon carbide crystal growth method. Background Silicon carbide (SiC) crystals are used as third-generation semiconductor materials, and have wide application prospects in high-temperature, high-frequency and high-voltage electronic devices due to high breakdown field strength, high thermal conductivity and excellent chemical stability. However, there are significant problems associated with the prior art silicon carbide crystal growth by expanding the diameter. In the prior art, a heater is additionally arranged at the top of a crucible in the diameter expansion process, and the growth atmosphere (such as Si/C gas phase) is deposited to the outer edge of the crystal to realize the diameter expansion growth through the action of a top thermal field, however, the mode is easy to cause the radial temperature gradient to be larger, so that the uniformity of the resistivity of each part of the crystal is reduced, and the included angle between the edge of the crystal and the inner wall of the diameter expansion ring is easy to accumulate the excessively saturated growth atmosphere, so that polysilicon carbide is separated out, the diameter expansion growth of the crystal single crystal is hindered, the crystal quality is reduced, and if the raw material for the crystal growth is reduced, a sufficient amount of growth atmosphere is difficult to be provided to meet the requirement of the diameter expansion growth. Based on the above, the present application has a technical problem in that the amount of the crystal expanding growth atmosphere is difficult to control. Disclosure of Invention The application aims at solving the problems in the prior art, and provides a silicon carbide crystal growth device and a silicon carbide crystal growth method, which solve the problem that the quantity of crystal expanding growth atmosphere is difficult to control in the prior art, and improve the quality of the crystal after expanding. The silicon carbide crystal growth device comprises a crucible, a diameter expanding ring, a partition component and a heating component, wherein the crucible is provided with a seed crystal fixing area at the top, the seed crystal fixing area is used for fixing seed crystals, the diameter expanding ring is arranged at the periphery side of the seed crystal fixing area and is provided with an inclined surface, the inclined surface extends towards the direction deviating from the seed crystal fixing area, the partition component comprises a partition ring, the partition ring is arranged at the bottom of the crucible and is opposite to the seed crystal fixing area, the periphery side of the partition ring is opposite to the inclined surface, the periphery side of the partition ring is used for arranging first raw materials, the cover body is connected to the partition ring and is detachably connected, the cover body is made of graphite or polycrystalline silicon carbide, the thickness of the cover body is less than or equal to 0.5mm, the cover body and the partition ring are enclosed to form a containing cavity, the containing cavity is used for arranging second raw materials, and the heating component comprises a first heater, the first heater is arranged at the periphery of the bottom of the crucible and acts on the second heater, and the first heater is arranged at the periphery of the crucible and acts on the second heater. Illustratively, a seed crystal fixing plate is generally provided at the top of the crucible, and the bottom surface of the seed crystal fixing plate serves as a seed crystal fixing area for fixing a seed crystal to the seed crystal fixing plate. The expanding ring is used for guiding the growth atmosphere to transmit and guiding the crystal expanding growth. The partition component is matched with the two heaters of the heating component, the partition ring and the cover body are utilized to seal the second raw material in the accommodating cavity, the first heater is controlled to enable the first raw material on the peripheral side of the partition ring to be heated and sublimated, the sublimated atmosphere of the first raw material is guided by the thermal field and the expanding ring to be deposited in the seed crystal fixing area, along with the crystal growth, the second heater is controlled to heat and melt through the cover body or erode by the sublimated atmosphere of the second raw material, the sublimated atmosphere of the second raw material is added into the crystal growth interface, the crystal growth atmosphere is divided into two stages to be supplied, the growth atmosphere is not excessive or insufficient, the polycrystalline silicon carbide is not precipitated while the stable expanding is ensured, the quality of the crystal