1. An MOCVD chamber structure, comprising:

a ceiling;

the graphite base is positioned below the ceiling, a gas flow channel is formed between the ceiling and the graphite base, a plurality of grooves are formed in the upper surface of the graphite base, and gas inlets are formed in the side walls of the grooves;

the graphite plates are respectively arranged in the corresponding grooves, and the air inlets are positioned above the graphite plates;

the cover plates are arranged above the corresponding graphite plates in an openable and closable manner respectively, and cover the corresponding graphite plates when the cover plates are closed;

the first gas path penetrates through the ceiling and is communicated with the gas flow channel;

and the second air path penetrates through the ceiling and is communicated with the air inlet on the side wall of the groove.

2. The MOCVD chamber structure of claim 1, wherein the depth of the groove is 30-60 mm.

3. The MOCVD chamber structure of claim 1, further comprising a graphite susceptor cover plate positioned above the center of the graphite susceptor, wherein the second gas passages pass through the graphite susceptor cover plate and communicate with gas inlets on the side walls of the grooves.

4. The MOCVD chamber body structure of claim 3, wherein the graphite susceptor cover plate is of quartz or graphite.

5. The MOCVD chamber body structure of claim 1, wherein a heater is arranged below the graphite susceptor.

6. The MOCVD cavity structure of claim 1, wherein the distance between the central line of the gas inlet on the side wall of the groove and the upper surface of the graphite disc is as follows: 5-10 mm.

7. The method for controlling the MOCVD cavity structure according to any one of claims 1 to 6, comprising the following steps:

starting the rotation of the graphite base and the graphite disc;

introducing a first raw material gas into the first gas path, wherein the first raw material gas enters the gas flow channel, introducing a second raw material gas into the second gas path, and the second raw material gas enters the groove through a gas inlet on the side wall of the groove;

selectively controlling the cover plate to be opened to expose the corresponding graphite disc, so that the first raw material gas enters the groove, and the first raw material in the first raw material gas and the second raw material in the second raw material gas are subjected to chemical reaction and then deposited on a substrate on the graphite disc;

the cover plate is selectively controlled to be closed, so that the cover plate covers the corresponding graphite plate.

8. The control method according to claim 7, wherein the rotation speed of the graphite susceptor is 100 to 500r/min, and the rotation speed of the graphite plate is 100 to 300 r/min.

9. An MOCVD reaction chamber, characterized by comprising the MOCVD cavity structure of any claim 1 to 6.

Background

The Metal Organic Chemical Vapor Deposition (MOCVD) equipment is the main equipment for producing semiconductor epitaxial materials at present and has wide application fields.

In a traditional planetary MOCVD reaction chamber, a graphite plate is placed in each circular concave area in a graphite base, and in one growth process, substrates on all the graphite plates can only grow the same epitaxial structure. For a complex structure containing multiple layers of different materials, in the development stage, multiple growth processes are required, and different single-layer materials or simple structures are grown to perform performance characterization. The traditional planetary MOCVD reaction chamber is used for preparing materials in the research stage, which wastes research and development expenses and lacks efficiency.

Disclosure of Invention

In order to solve the problems, the application provides an MOCVD cavity structure, a control method thereof and an MOCVD reaction chamber, so that different epitaxial structures can be grown on different graphite plates.

An embodiment of the present application provides an MOCVD cavity structure, including: a ceiling; the graphite base is positioned below the ceiling, a gas flow channel is formed between the ceiling and the graphite base, a plurality of grooves are formed in the upper surface of the graphite base, and gas inlets are formed in the side walls of the grooves; the graphite plates are respectively arranged in the corresponding grooves, and the air inlets are positioned above the graphite plates; the cover plates are arranged above the corresponding graphite discs in an openable and closable manner respectively, and cover the corresponding graphite discs when the cover plates are closed; the first gas path penetrates through the ceiling and is communicated with the gas flow channel; and the second air path penetrates through the ceiling and is communicated with the air inlet on the side wall of the groove.

According to some embodiments of the application, the depth of the groove is 30mm to 60 mm.

According to some embodiments of the present application, the MOCVD chamber structure further comprises a graphite susceptor cover plate located above the center of the graphite susceptor, and the second gas path passes through the graphite susceptor cover plate and communicates with the gas inlet on the side wall of the groove.

According to some embodiments of the present application, the graphite susceptor cover plate is of quartz or graphite.

According to some embodiments of the present application, a heater is provided below the graphite susceptor.

According to some embodiments of the application, the distance between the centre line of the air inlet on the side wall of the groove and the upper surface of the graphite disc is: 5-10 mm.

An embodiment of the present application provides a method for controlling an MOCVD cavity structure, including: starting the rotation of the graphite base and the graphite disc; introducing a first raw material gas into the first gas path, wherein the first raw material gas enters the gas flow channel, introducing a second raw material gas into the second gas path, and the second raw material gas enters the groove through a gas inlet on the side wall of the groove; selectively controlling the cover plate to be opened to expose the corresponding graphite disc, so that the first raw material gas enters the groove, and the first raw material in the first raw material gas and the second raw material in the second raw material gas are subjected to chemical reaction and then are deposited on the substrate on the exposed graphite disc; the cover plate is selectively controlled to be closed, so that the cover plate covers the corresponding graphite plate.

According to some embodiments of the present application, the rotation speed of the graphite susceptor is 100 to 500r/min, and the rotation speed of the graphite plate is 100 to 300 r/min.

One embodiment of the present application provides an MOCVD reaction chamber comprising an MOCVD cavity structure as described above.

According to the MOCVD cavity structure, the air inlet is formed in the side wall of the groove of the graphite base, so that second raw materials can enter the groove from the air inlet, the openable cover plate is arranged above the graphite plate, when the cover plate is opened, first raw materials enter the groove, the first raw materials and the second raw materials are subjected to chemical reaction and then deposited on the substrate on the graphite plate, and when the cover plate is closed, the first raw materials cannot enter the groove, so that the deposition is limited; the cover plates of the grooves are controlled respectively, so that various different epitaxial structures can grow in one growth process, the production cost is reduced, and the research and development efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for a person skilled in the art to obtain other drawings based on these drawings without exceeding the protection scope of the present application.

FIG. 1 is a schematic diagram of a MOCVD chamber structure according to an embodiment of the present disclosure;

Detailed Description

The technical solutions of the present application will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, not all, of the embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

As shown in fig. 1, the present embodiment provides an MOCVD chamber structure 100. The MOCVD cavity structure 100 includes a ceiling 1, a graphite susceptor 2, a graphite plate 3, a cover plate 4, a first gas path 5, and a second gas path 6.

The ceiling 1 is located at the uppermost part of the MOCVD chamber structure 100. The ceiling 1 can be made of quartz or graphite, and deposition of raw materials on the ceiling 1 is avoided as much as possible.

The graphite base 2 is arranged below the ceiling 1, and the distance between the ceiling 1 and the graphite base 2 can be determined according to requirements. A gas flow passage is formed between the ceiling 1 and the graphite base 2. Optionally, the ceiling 1 and the graphite base 2 of the present embodiment are both cylindrical. The graphite susceptor 2 is provided with a plurality of grooves 21 on its upper surface. In this embodiment, a plurality of grooves 21 are uniformly distributed around the circumference of the axis of the graphite susceptor 2. The number of grooves 21 is determined as required. The side wall of the groove 21 is provided with an air inlet 22.

The graphite plates 3 are arranged in the grooves 21, and the number of the graphite plates 3 is the same as that of the grooves 21. One graphite disc 3 is provided in each recess 21. Optionally, the axis of the graphite disc 3 is parallel to the axis of the graphite susceptor 2, and the graphite disc 3 is rotatably disposed in the groove 21 to facilitate more uniform vapor deposition. A substrate is arranged on the graphite plate 3, and the raw materials are subjected to vapor deposition on the substrate. The gas inlet 22 is positioned above the graphite plate 3 so that the raw material introduced through the gas inlet 22 flows across the substrate.

The number of the cover plates 4 is multiple, and the number of the cover plates 4 is the same as that of the graphite plates 3. A cover plate 4 is arranged above each graphite disc 3. Optionally, the cover plate 4 is disposed at the top end opening of the groove 21. The cover plate 4 can be opened or closed by the drive of the driver. When the cover plate 4 is opened, exposing the corresponding graphite disc, the raw material-carrying gas above the grooves 21 can enter the grooves 21. The raw material entering from above the groove 21 reacts with the raw material input from the gas inlet 22 under certain conditions and then vapor-phase deposition is performed on the substrate. When the cover plate 4 is closed, the cover plate 4 covers the corresponding graphite plate 3, and the raw material-carrying gas above the grooves 21 cannot enter the grooves 21. Optionally, the driver of the cover plate 3 is a motor, the motor is connected with a gear, the cover plate 4 is connected with a rack matched with the gear, and the cover plate 4 is driven to open and close by the motor.

In this embodiment, the respective cover plates 4 are controlled by a controller. Each cover plate 4 is individually controlled to open or close for different vapor deposition in different recesses 21 to obtain different epitaxial structures.

The first air path 5 passes through the ceiling 1 and is communicated with the air flow channel. The first gas path 5 is used for conveying a first raw material for MOCVD. Optionally, the first raw material in this embodiment is an organic compound of a group iii element. The first gas path 5 extends to the upper part of the groove 21, so that the first raw material gas carrying the first raw material can enter the groove 21 conveniently. The off-gas of the first raw material gas is discharged through the opening formed by the edge of the ceiling 1 and the edge of the graphite susceptor 2. "·" in fig. 1 denotes the first feed gas.

The second gas path 6 passes through the ceiling 1 and is communicated with the gas inlet 22 on the side wall of the groove 21, and the second gas path 6 is used for conveying the MOCVD second raw material. Alternatively, the second raw material of the present embodiment is a hydride of a group V element. A second feed gas carrying the second feed material enters the groove 21 via the gas inlet 22. "X" in FIG. 1 represents a second feed gas.

Optionally, a gap is provided between the cover plate 4 and the inner wall of the groove 21 for exhaust of the second feed gas. First gas circuit 5 and second gas circuit 6 all are located the center department of canopy 1, are convenient for the transport of first raw material gas and second raw material gas. The port of the second air path 6 communicating with the air inlet 22 is a circular opening, and when the graphite base 2 works, the second air path 6 does not rotate, and the circular opening of the second air path 6 can ensure that the second air path 6 is always communicated with the air inlet 22.

The MOCVD chamber body structure 100 of the present embodiment is different from the conventional planetary reaction chamber, wherein the gas inlets 22 are provided on the side walls of the grooves of the graphite susceptor 2, and the second raw material gas enters the grooves 21 through the gas inlets 22, so that the flow coverage of the second raw material on the surface of the substrate is not affected no matter the cover plate 3 is opened or closed. The first raw material gas is conveyed to the upper part of the groove 21 through the first gas path 5, and whether the first raw material can enter the groove 21 or not can be controlled by controlling the opening and closing of the cover plate, so that whether the vapor deposition is carried out or not can be controlled. In the primary growth process, the opening and closing of each cover plate 3 are controlled differently, so that different epitaxial materials can grow on different substrates.

According to an optional technical scheme of this application, the degree of depth of recess 21 is 30mm ~ 60mm, is convenient for the setting of air inlet 22. Alternatively, the depth of the groove 21 of the present embodiment is about 10mm greater than the conventional groove depth.

According to an alternative embodiment of the present application, the MOCVD chamber structure 100 further includes a graphite susceptor cover plate 7, wherein the graphite susceptor cover plate 7 is located above the center of the graphite susceptor 2. Optionally, a graphite base cover plate 7 is attached to the canopy 1. The edge of the graphite susceptor cover plate 7, which is close to the upper edge of the groove 21, avoids deposition of raw material on the components below the graphite susceptor cover plate 7. The second air passage 6 passes through the graphite susceptor cover plate 7 and communicates with the air inlet 22 on the side wall of the groove 21.

According to an optional technical scheme of the application, the graphite base covering plate 7 is made of quartz or graphite, so that the graphite base 2 can be well protected, and the cost is low.

According to an optional technical scheme of this application, the below of graphite base is equipped with heater 8. The heater 8 is used to heat the graphite disk 3 and the substrate is typically at 500 ℃ and 1200 ℃ for reaction and deposition. Alternatively, the heater 8 is a high frequency induction coil.

According to an alternative embodiment of the present application, the distance between the centerline of the inlet 22 on the side wall of the groove and the upper surface of the graphite plate is: 5-10 mm, so that the second raw material gas can cover the surface of the substrate conveniently.

The embodiment also provides a control method of the MOCVD cavity structure, which comprises the following steps:

and S1, starting the rotation of the graphite base and the graphite disc.

S2, starting a heater to heat, introducing a second raw material gas into the second gas path when the temperature in the groove rises to a first preset temperature, and enabling the second raw material gas to enter the groove through a gas inlet in the side wall of the groove; when the temperature in the groove rises to a second preset temperature, introducing first raw material gas into the first gas path, and enabling the first raw material gas to enter the gas flow channel; the first preset temperature and the second preset temperature are set according to requirements, and if the first preset temperature is 400 ℃ and the second preset temperature is 650 ℃.

S3, selectively controlling the cover plate to open to expose the corresponding graphite plate, so that the first raw material in the first raw material gas enters the grooves, and the first raw material in the first raw material gas and the second raw material in the second raw material gas undergo a chemical reaction and then deposit on the substrate on the exposed graphite plate; selectively controlling the cover plate to close, wherein the cover plate covers the corresponding graphite disc, so that the first raw material cannot enter the groove, and the deposition is stopped.

Through controlling different cover plates respectively, different epitaxial materials can grow on different substrates in one-time growth process, production cost is saved, and research and development efficiency is improved.

According to an optional technical scheme of the application, the rotation speed of the graphite base is 100-500 r/min, and the rotation speed of the graphite disc is 100-300 r/min.

The embodiment also provides an MOCVD reaction chamber, which comprises the MOCVD cavity structure.

The embodiments of the present application are described in detail above. The principle and the implementation of the present application are explained herein by applying specific examples, and the above description of the embodiments is only used to help understand the technical solutions and the core ideas of the present application. Therefore, the person skilled in the art should, according to the idea of the present application, change or modify the embodiments and applications of the present application based on the scope of protection of the present application. In view of the above, the description should not be taken as limiting the application.