TW201819696A - 4H-SiC crystal growth equipment and method thereof - Google Patents

Abstract

This invention provides a 4H-SiC crystal growth equipment and a method thereof, and the 4H-SiC crystal growth equipment comprising: a crystal growth furnace; a carbon graphite crucible, disposed in the crystal growth furnace; a carbon source and silicon source supply system, including a gas source and a gas outlet; one end of the gas outlet connected with the gas source, the other end of the gas outlet extending from the top of the crystal growth furnace to the inner of the carbon graphite crucible and being above the carbon source and the silicon source; a heater, mounted in the crystal growth furnace and being around the carbon graphite crucible. Via the carbon source and silicon source supply system, the supplements of the carbon source and the silicon source can be enough. Simultaneously, the carbon and the silicon sources don't effect a temperature of a carbon and silicon source solution adversely and 4H-SiC crystal doesn't exist defects because they are formed at the surface of the carbon and silicon source solution in the form of SiC.

Description

   Silicon carbide crystal (4H-SiC) growth equipment and method   

The invention belongs to the technical field of crystal growth, and particularly relates to a silicon carbide crystal (4H-SiC) growth device and method.

In the prior art, the growth methods of silicon carbide crystals (4H-SiC) mainly include TSM (Traveling Solvent Method), SCT (Slow Cooling Technique, slow cooling method), VLS (Vapor Liquid Solid, vapor liquid solid Growth method) and TSSG (Top Seeded Solution Growth).

The equipment for growing silicon carbide crystals (4H-SiC) by the TSSG method is shown in FIG. 1 and includes a crystal growth furnace 10; a support frame 11 is located in the crystal growth furnace 10 and is located at the bottom of the crystal growth furnace 10; A graphite crucible 12 is located in the crystal growth furnace 10 and is located on the top of the support frame 11; a base 15 is located in the crystal growth furnace 10 and is located around the graphite crucible 12; a heat insulation layer 16 Is located in the crystal growth furnace 10 and is located around the base 15; heater 17 is located in the crystal growth furnace 10 and is located around the heat insulation layer 16. When using the above equipment to grow 4H-silicon carbide using the TSSG method, the seed crystal 13 is placed on the bottom of the graphite crucible 12, and the carbon source and the silicon source 14 are placed in the graphite crucible 12, and the heater 17 is used. The heating causes the carbon source and the silicon source 14 to be melted into a liquid. When the temperature is suitable, a silicon carbide crystal (4H-SiC) is formed on the surface of the seed crystal 13. During the process of growing silicon carbide crystals (4H-SiC) using the TSSG method described above, since the carbon source and silicon source 14 are placed in the graphite crucible 12, the graphite crucible 12 can provide silicon carbide crystals (4H-SiC) ) The carbon source required for growth makes the carbon source continue to be supplied during the growth of silicon carbide crystal (4H-SiC), but the silicon source required for the growth of silicon carbide crystal (4H-SiC) is very limited. Crystal (4H-SiC) growth The lack of silicon source will affect the crystal growth.

In view of the problems existing in the above equipment, an improved device is shown in FIG. 2. The device shown in FIG. 2 adds a carbon source and a silicon source supplement container 18 on the basis of the device in FIG. 1. The carbon source A supplemental carbon source and a silicon source 19 are placed in the silicon source replenishment container 18. During the growth of silicon carbide crystal (4H-SiC), the carbon source and silicon source replenishment container 18 continues to add the carbon crucible 12 to the graphite crucible 12 The supplementary carbon source and silicon source 19 are described to ensure the carbon source and silicon source required for the growth of the silicon carbide crystal (4H-SiC). However, after the carbon source and the silicon source supplement container 18 for providing the supplemental carbon source and the silicon source 19 are added to the equipment as shown in FIG. 2, during the process of growing silicon carbide crystal (4H-SiC), the supplemental carbon The continuous addition of the source and the silicon source 19 will cause the temperature of the molten carbon source and the silicon source 14 in the graphite crucible 12 to decrease, thereby causing defects in the grown silicon carbide crystal (4H-SiC).

The purpose of the present invention is to overcome the defects in the prior art and provide a silicon carbide crystal (4H-SiC) growth equipment and method, which are used to solve the problem that the silicon carbide crystal (4H-SiC) growth equipment in the prior art cannot continuously supplement the silicon carbide crystal The problem of the silicon source required for (4H-SiC) growth and the carbon source and silicon required for crystal growth caused by the continuous addition of carbon and silicon sources to the graphite crucible during the growth of silicon carbide crystals (4H-SiC) The source solution is reduced, so that the grown silicon carbide crystal (4H-SiC) memory is defective.

In order to achieve the above object and other related objectives, the present invention provides a silicon carbide crystal (4H-SiC) growth equipment, the silicon carbide crystal (4H-SiC) growth equipment includes: a crystal growth furnace; a graphite crucible, located in the crystal growth Inside the furnace; the graphite crucible is suitable for placing carbon and silicon sources required for the growth of silicon carbide crystals (4H-SiC); the carbon and silicon source supply system includes a gas source and a gas pipe; The gas source is connected, and the other end extends from the top of the crystal growth furnace to a carbon source and a silicon source in the graphite crucible; the carbon source and the silicon source supply system are adapted to the A carbon source gas and a silicon source gas are introduced into the crystal growth furnace to form silicon carbide on the surface of the carbon source and the silicon source; a heater is located in the crystal growth furnace and is located around the graphite crucible, and is suitable for During the crystal growth process, the carbon source and the silicon source in the graphite crucible are heated to cause them to melt, and the carbon source gas and the silicon source gas are provided with a temperature required for a reaction.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth equipment of the present invention, the carbon source gas is a carbon-containing compound.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth equipment of the present invention, the carbon source gas is C _n H _{n + 2} , where n 1.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth device of the present invention, the silicon source gas includes SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , and Si ₂ Cl ₆ .

As a preferred solution of the silicon carbide crystal (4H-SiC) growth equipment of the present invention, the silicon carbide crystal (4H-SiC) growth equipment further includes a first exhaust hole, and the first exhaust hole is located in the crystal The bottom of the growing furnace.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth equipment of the present invention, the graphite crucible includes a crucible body and a cover body; the cover body is buckled on the top of the crucible body, the carbon source and the The silicon source is located in the crucible body, and the gas pipe extends through the cover body into the crucible body; the cover body is provided with a second exhaust hole penetrating vertically.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth device of the present invention, the heater includes at least one of a radio frequency heater, a resistance heater, or an infrared heater.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth equipment of the present invention, the silicon carbide crystal (4H-SiC) growth equipment further includes a cooling wall, which is located in the crystal growth furnace and is located in Between the heater and the graphite crucible.

As a preferred solution of the silicon carbide crystal (4H-SiC) growth equipment of the present invention, the silicon carbide crystal (4H-SiC) growth equipment further includes a support frame, the support frame is located in the crystal growth furnace, and the A graphite crucible is located on the top of the support frame.

The invention also provides a method for growing silicon carbide crystals (4H-SiC). When the silicon carbide crystals (4H-SiC) are grown, a carbon source gas and a silicon source gas are introduced into the crystal growth furnace for use in growing carbonization. Silicon carbide (4H-SiC) forms silicon carbide on the carbon source and the surface of the silicon source.

As a preferred solution of the method for growing silicon carbide crystals (4H-SiC) of the present invention, the silicon carbide crystals (4H-SiC) are grown by a top seed crystal pulling method.

As a preferred solution of the method for growing silicon carbide crystal (4H-SiC) according to the present invention, a temperature at which the carbon source gas reacts with the silicon source gas to form the silicon carbide is 1000 ° C. to 1800 ° C.

The silicon carbide crystal (4H-SiC) growth device and method of the present invention have the following beneficial effects: By adding a carbon source and a silicon source supply system, the silicon carbide crystal (4H-SiC) growth device of the present invention can -SiC) provides sufficient carbon and silicon source replenishment during the growth process; at the same time, because the supplemental carbon source and silicon source are formed in the form of silicon carbide on the surface of the carbon source and silicon source solution, the carbon source and silicon source solution will not be affected. The temperature of the silicon source solution adversely affects and no defects are generated in the grown silicon carbide crystal (4H-SiC).

10‧‧‧ Crystal Growth Furnace

11‧‧‧ support

12‧‧‧graphite crucible

13‧‧‧seed

14‧‧‧ Carbon source and silicon source

15‧‧‧ base

16‧‧‧ Insulation

17‧‧‧ heater

18‧‧‧ Carbon source and silicon source supplement container

19‧‧‧Supplement of carbon and silicon sources

20‧‧‧ Crystal Growth Furnace

21‧‧‧ support frame

22‧‧‧Graphite Crucible

221‧‧‧ Crucible body

222‧‧‧ Cover

2221‧‧‧Second exhaust hole

23‧‧‧gas tube

24‧‧‧ Carbon source and silicon source

25‧‧‧heater

26‧‧‧First exhaust hole

27‧‧‧ cooling wall

28‧‧‧ Seed

FIG. 1 and FIG. 2 are schematic structural diagrams of a silicon carbide crystal (4H-SiC) growth apparatus provided in the prior art.

FIG. 3 is a schematic diagram showing a structure of a silicon carbide crystal (4H-SiC) growth apparatus according to the present invention.

FIG. 4 is a schematic diagram showing a temperature distribution inside a silicon carbide crystal (4H-SiC) growth device of the present invention during a crystal growth process.

The following describes the embodiments of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific implementations, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figures 3 to 4. It should be noted that the illustrations provided in this embodiment only illustrate the basic idea of the present invention in a schematic manner, although the illustrations only show the components related to the present invention and not the number, shape and For size drawing, the type, quantity, and proportion of each component can be changed at will in actual implementation, and the layout of the components may be more complicated.

Embodiment one:

Referring to FIG. 3, the present invention provides a silicon carbide crystal (4H-SiC) growth equipment. The silicon carbide crystal (4H-SiC) growth equipment includes: a crystal growth furnace 20; a graphite crucible 22, the graphite crucible 22 is located at Inside the crystal growth furnace 20; the graphite crucible 22 is suitable for placing a carbon source and a silicon source 24 required for the growth of silicon carbide crystals (4H-SiC); a carbon source and a silicon source supply system, the carbon source and the silicon source The supply system includes a gas source (not shown) and a gas pipe 23; one end of the gas pipe 23 is connected to the gas source, and the other end extends from the top of the crystal growth furnace 20 to the inside of the crystal growth furnace 20 And extends above the carbon source and silicon source 24 in the graphite crucible 22; the carbon source and silicon source supply system is adapted to pass a carbon source gas into the crystal growth furnace 20 during the crystal growth process And a silicon source gas to form silicon carbide on the surface of the carbon source and the silicon source 24; a heater 25, which is located in the crystal growth furnace 20 and located around the graphite crucible 22, is suitable for The carbon source and the silicon source 24 in the graphite crucible 22 during the crystal growth process Heat to make it melt, and provide the temperature required for the carbon source gas and the silicon source gas to react, so as to ensure that the carbon source gas and the silicon source gas passed into the crystal growth furnace 20 can react Formation of silicon carbide. By adding the carbon source and the silicon source supply system, it is possible to provide the crystal growth furnace 20 with sufficient silicon carbide crystal (4H-SiC) growth required during the silicon carbide crystal (4H-SiC) growth process. Carbon source and silicon source replenishment; meanwhile, the form of silicon carbide is formed on the surface of the molten carbon source and silicon source 24 due to the reaction between the carbon source gas and the silicon source gas that is passed in, and the molten carbon source is not affected. And the temperature of the silicon source 24 adversely affects, and no defects are generated in the grown silicon carbide crystal (4H-SiC).

As an example, the carbon source gas may be all carbon-containing compounds. Preferably, in this embodiment, the carbon source gas is C _n H _{n + 2} , where n 1.

As an example, the silicon source gas includes SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHC ₁₃ , SiCl ₄ , Si ₂ Cl ₆ , and the silicon source gas may be SiH ₄ , Si ₂ H ₆ , SiH Any one of ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , and Si ₂ Cl ₆ , any two, or a combination of two or more.

As an example, the silicon carbide crystal (4H-SiC) growth device further includes a first exhaust hole 26 located at the bottom of the crystal growth furnace 20; the first exhaust hole 26 It is suitable for exhausting excess carbon source gas, silicon source gas, and the reaction generated gas of the two, so as to reduce the pressure in the crystal growth furnace 20, so as to reduce the impact of the carbon source gas and the silicon source gas on the The adverse effects of silicon carbide crystal (4H-SiC) growth are described.

As an example, the graphite crucible 22 includes a crucible body 221 and a cover 222; the cover 222 is buckled on the top of the crucible body 221, and the carbon source and the silicon source 24 are located in the crucible body 221 The gas delivery pipe 23 extends through the cover 222 into the crucible body 221; the cover 222 is provided with a second exhaust hole 2221 penetrating vertically; the second exhaust hole 2221 is suitable for Excess carbon source gas, silicon source gas, and the reaction generated gas of the two are discharged from the graphite crucible 22 and discharged from the crystal growth furnace 20 through the first exhaust hole 26 to reduce the crystal growth furnace. 20 to reduce the adverse effect on the growth of the silicon carbide crystal (4H-SiC) after the carbon source gas and the silicon source gas are introduced.

As an example, the heater 25 includes at least one of a radio frequency (radio frequency) heater, a resistance heater, or an infrared (infrared) heater; that is, the heater 25 may be a radio frequency heater; it may also be a resistance heater; It can also be an infrared heater; it can also be a combination of an RF heater and a resistance heater, a combination of a resistance heater and an infrared heater, a combination of an RF heater and an infrared heater, an RF heater, a resistance heater, and infrared heating Device combination.

As an example, the silicon carbide crystal (4H-SiC) growth device further includes a cooling wall 27 located in the crystal growth furnace 20 and between the heater 25 and the graphite crucible 22 .

As an example, the silicon carbide crystal (4H-SiC) growth device further includes a support frame 21 located in the crystal growth furnace 20, and the support frame 21 is used to support the graphite crucible 22, that is, The graphite crucible 22 is located on the top of the support frame 21.

The working principle of the silicon carbide crystal (4H-SiC) growth device of the present invention is: placing a seed crystal 28, the carbon source and silicon source 24 in the graphite crucible 22, and installing the seed crystal 28, The graphite crucible 22 of the carbon source and the silicon source 24 is placed in the crystal growth furnace 20, and the heater 25 is used to heat the carbon source and the silicon source 24 to melt. When the temperature is suitable, the carbonization A silicon crystal (4H-SiC) is formed on the surface of the seed crystal 28; the carbon source and the silicon source supply system can be inserted into the crystal growth furnace 20 when the silicon carbide crystal (4H-SiC) starts to grow. The carbon source gas and the silicon source gas may be introduced, or the carbon source gas and the silicon may be introduced into the crystal growth furnace 20 after the silicon carbide crystal (4H-SiC) is grown for a period of time. Source gas. During the growth of the silicon carbide crystal (4H-SiC), the temperature in the crystal growth furnace 20 is shown in FIG. 4. As can be seen from FIG. 4, the maximum temperature in the graphite crucible 20 can also reach 1800. ℃, and the temperature required for the carbon source to react with the silicon source to generate the silicon carbide is 1000 ° C to 1800 ° C. It can be seen that during the growth of the silicon carbide crystal (4H-SiC), the The heater 25 may provide a temperature required for the carbon source to react with the silicon source.

Embodiment two:

The invention also provides a method for growing silicon carbide crystals (4H-SiC). When the silicon carbide crystals (4H-SiC) are grown, a carbon source gas and a silicon source gas are introduced into the crystal growth furnace for use in growing carbonization. Silicon carbide (4H-SiC) forms silicon carbide on the carbon source and the surface of the silicon source. The method for growing silicon carbide crystals (4H-SiC) is performed in the silicon carbide crystal (4H-SiC) growth equipment described in Example 1. The specific structure of the silicon carbide crystal (4H-SiC) growth equipment and For the working principle, please refer to the first embodiment, which will not be repeated here.

As an example, the top seed crystal pulling method (TSSG) is used to grow the silicon carbide crystal (4H-SiC).

As an example, the temperature at which the carbon source gas reacts with the silicon source gas to form the silicon carbide is 1000 ° C to 1800 ° C.

In summary, the present invention provides a silicon carbide crystal (4H-SiC) growth equipment and method. The silicon carbide crystal (4H-SiC) growth equipment includes: a crystal growth furnace; a graphite crucible located in the crystal growth furnace. The graphite crucible is suitable for placing a carbon source and a silicon source required for the growth of silicon carbide crystals (4H-SiC); a carbon source and a silicon source supply system including a gas source and a gas pipe; one end of the gas pipe and the gas The source is connected, and the other end extends from the top of the crystal growth furnace to the carbon source and silicon source in the graphite crucible; the carbon source and silicon source supply system is adapted to grow to the crystal during the crystal growth process. A carbon source gas and a silicon source gas are passed into the furnace to form silicon carbide on the surface of the carbon source and the silicon source; a heater is located in the crystal growth furnace and is located around the graphite crucible, and is suitable for During the growth process, the carbon source and the silicon source in the graphite crucible are heated to melt them, and the carbon source gas and the silicon source gas are provided with a temperature required for a reaction. By adding a carbon source and a silicon source supply system, the silicon carbide crystal (4H-SiC) growth device of the present invention can provide sufficient carbon source and silicon source replenishment during the growth process of the silicon carbide crystal (4H-SiC); at the same time, Since the supplemental carbon source and silicon source are formed on the surface of the carbon source and silicon source solution in the form of silicon carbide, the temperature of the carbon source and silicon source solution will not adversely affect the growth of silicon carbide crystals (4H-SiC). No defects.

The above-mentioned embodiments merely exemplify the principle of the present invention and its effects, and are not intended to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field to which they belong without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the scope of patent application of the present invention.

Claims (12)

    A silicon carbide crystal (4H-SiC) growth device includes: a crystal growth furnace; a graphite crucible located in the crystal growth furnace; the graphite crucible is suitable for placing a carbon source required for the growth of silicon carbide crystal (4H-SiC) And a silicon source; a carbon source and a silicon source supply system including a gas source and a gas pipe; one end of the gas pipe is connected to the gas source, and the other end extends from the top of the crystal growth furnace into the graphite crucible Above the carbon source and the silicon source; the carbon source and the silicon source supply system are adapted to pass a carbon source gas and a silicon source gas into the crystal growth furnace during a crystal growth process so as to surface the carbon source and the silicon source Forming silicon carbide; a heater, located in the crystal growth furnace and at the periphery of the graphite crucible, is suitable for heating the carbon source and silicon source in the graphite crucible to cause melting during the crystal growth process And provide a temperature required for the carbon source gas and the silicon source gas to react.         The silicon carbide crystal (4H-SiC) growth apparatus according to claim 1, wherein the carbon source gas is a carbon-containing compound.     The silicon carbide crystal (4H-SiC) growth apparatus according to claim ₂ , wherein the carbon source gas is C _n H _{n + 2} , where n 1. The silicon carbide crystal (4H-SiC) growth apparatus according to claim 1, wherein the silicon source gas includes SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , Si ₂ Cl ₆ .     The silicon carbide crystal (4H-SiC) growth apparatus according to claim 1, wherein the silicon carbide crystal (4H-SiC) growth apparatus further includes a first exhaust hole, and the first exhaust hole is located in the crystal The bottom of the growing furnace.         The silicon carbide crystal (4H-SiC) growth equipment according to claim 1, wherein the graphite crucible includes a crucible body and a cover body; the cover body is buckled on the top of the crucible body, the carbon source and the The silicon source is located in the crucible body, and the gas pipe extends through the cover body into the crucible body; the cover body is provided with a second exhaust hole penetrating vertically.         The silicon carbide crystal (4H-SiC) growth apparatus according to claim 1, wherein the heater includes at least one of a radio frequency heater, a resistance heater, or an infrared heater.         The silicon carbide crystal (4H-SiC) growth equipment according to claim 1, wherein the silicon carbide crystal (4H-SiC) growth equipment further includes a cooling wall, the cooling wall is located in the crystal growth furnace, and is located in the crystal growth furnace. The heater and the graphite crucible.         The silicon carbide crystal (4H-SiC) growth equipment according to claim 1, wherein the silicon carbide crystal (4H-SiC) growth equipment further comprises a support frame, the support frame is located in the crystal growth furnace, and the graphite The crucible is located on the top of the support frame.         A method for growing silicon carbide crystals (4H-SiC) includes: introducing carbon source gas and silicon source gas into a crystal growth furnace while growing silicon carbide crystals (4H-SiC); and growing silicon carbide crystals. (4H-SiC) The surface of the carbon source and silicon source forms silicon carbide.         The method for growing a silicon carbide crystal (4H-SiC) according to claim 10, wherein the silicon carbide crystal (4H-SiC) is grown using a top seed crystal pulling method.         The method for growing silicon carbide crystal (4H-SiC) according to claim 10, wherein a temperature at which the carbon source gas reacts with the silicon source gas to form the silicon carbide is 1000 ° C to 1800 ° C.