KR100578089B1 - Hydride vapor phase epitaxy unit - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydride vapor deposition reactor, which aims to deposit a uniform thick film over the entire area of the substrate surface.

The hydride vapor deposition reactor according to the present invention includes a reaction chamber (10) having a head (11) and maintaining a vacuum; A susceptor 20 rotatably installed in the reaction chamber and having a plurality of substrates P mounted thereon; Gas injection means (30) for injecting gas into the susceptor to form a film on the surface of the substrate; And a heating means for heating the susceptor, wherein the gas injection means divides the inside of the reaction chamber into upper and lower spaces 13 and 14 and has a plurality of injection holes 33a, The first gas pipe 31 and the standing portion in which the injection unit communicates with the first space above the injection plate such that the first gas is injected through the injection hole of the injection plate 33 via the first space 13. A source holder 36 coupled to the inside of the rotating shaft of the acceptor and receiving a solid source 35 therein, and a lower injection part 32c is disposed inside the source holder while penetrating through the center of the injection plate so that a second gas is formed. The second gas pipe 32 is injected to the surface of the susceptor after passing through the source holder and reacts with the first gas.

Hydride Vapor Deposition Reactor, HVPE, Susceptor, Solid Source, Jet Plate

Description

Hydride Vapor Deposition Reactor {HYDRIDE VAPOR PHASE EPITAXY UNIT}

1 is a schematic diagram of a horizontal hydride vapor deposition reactor according to the prior art.

2 is a block diagram of a hydride vapor deposition reactor according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: reaction chamber, 13,14: space

20: susceptor, 30: gas injection means

31, 32: gas pipe, 33: jet plate

34: coolant flow path, 40: induction coil

The present invention relates to a hydride vapor deposition reactor, and more particularly, a hydride vapor deposition reactor which allows a high-quality thick film to be uniformly grown throughout the entire area by smoothly flowing a heterogeneous gas for depositing a thick film on a substrate. It is about.

In general, a semiconductor is manufactured through a process of constructing an electric circuit by repeatedly performing diffusion, photography, etching, and thin film processes on a raw material wafer.

Substrate, which is the most basic and important for semiconductor production, has a decisive influence on the quality of electronic devices, so the material and quality of the substrate are very important. Conventional gallium nitride (GaN) thin film growth is the absence of substrates required for homogeneous bonding in gallium nitride thin film growth. Mostly sapphire (Al2O3), gallium arsenide (GaAs), silicon carbide (SiC), gallium phosphide (GaP) And growing a substrate such as silicon (Si) were used. However, many defects are caused by the difference between the lattice constant and thermal coefficient of the substrate and the thin film to be grown, and many efforts have been made to solve this problem. In addition, the production of GaN thick film by the existing initial method requires more than a thousand times the conditions of the existing pressure and temperature, but until now have been experiencing a lot of difficulties in manufacturing.

Therefore, in order to grow a high quality thin film for semiconductor devices, a high-quality thick film is grown in a short time using a high growth rate hydride vapor phase vapor deposition (HYDRIDE VAPOR PHASE EPITAXY, HVPE) equipment to remove the initial substrate into a material such as a thick film. High quality thin films can be produced economically and efficiently.

Hydrogen vapor deposition, one of chemical vapor deposition, is a method of forming a thick film on a heated substrate by using pyrolysis and reactivity of a gas injected into a reactor. By injecting the pyrolysis and chemical reaction of the reaction gas and ammonia gas generated by the chemical reaction between the solid source (Ga, In, Al, Zn, Mg) and hydrochloric acid gas, the nitride thick film is grown on the substrate. It has a very high nitride growth efficiency, so the growth rate is very fast, maintenance costs and production costs are very low compared to other growth methods, it is easy to maintain with a relatively simple operation principle.

As shown in FIG. 1, the hydride vapor deposition reactor according to the prior art includes a reaction tube 1 isolated from the outside, and a susceptor 2 installed inside the reaction tube 1 and on which the substrate P is seated. and a gas gas pipe for injecting gas to form a thin film on the substrate P seated on the susceptor 2. The reaction tube 1 is open at both sides, and a cap 1a is coupled to each of the openings in order to vacuum seal the inside thereof.

The gas gas pipe is divided into first, second and third gas pipes 3, 4 and 5 for injecting different gases.

In particular, the overall gas flow causes nitrogen to flow through the second gas pipe 4 to produce a constant gas flow inside the reaction tube 1, and the hydrochloric acid gas and chemicals are introduced into the third gas pipe 5 within the gas flow. The solid source 6 causing the reaction is inserted, and ammonia gas flows into the first gas pipe 3 to grow. For insertion of the solid source 6, the end of the third gas pipe 5 is extended relative to the other section.

In the figure, reference numeral 7 denotes a tubular electric furnace.

According to the reactor according to the prior art there are the following problems.

Since the reaction tube 1 is in the form of a tube, it is inappropriate to mount the susceptor 5 in a rotatable manner, and in order to replace the solid source 6 inserted into the third gas tube 6, the reaction tube 1 After removing the cap (1a) of the), it is necessary to remove the solid source (6) inserted into the third gas pipe (6), in which case the incoming gas is a solid source because there is a depth to the center of the reaction tube (1) Since gas gas pipes 3, 4, and 5 must be installed long so that they can react independently with (6), accessibility is bad, and the first gas (ammonia) gas pipe 3 has to be complicated, so it is inconvenient to install.

In addition, the maintenance of a large amount of gas involves a lot of costs, and in the horizontal structure, the temperature of the gas rises in the flow direction and convection and diffusion cause the first gas pipe 3 and the third gas. The gas composition ratio of nitrogen decomposed in the ammonia is different from the solid source 6 on the substrate and the back on the substrate due to the convection and diffusion of the gases from the gas pipe 5.

That is, nonuniformity of the composition ratio of the solid source 6 and the nitrogen of the growth layer occurs, and the growth rate of the front and rear sides is changed in the gas flow direction inside the substrate P, so that all of the substrates P have uniform characteristics. Hard to get In addition, in order to grow a plurality of substrates (P) a constant temperature must be formed in a large area in the gas flow direction, which requires a very long electric furnace. As a result, it is difficult to use one or more substrates P, and a tendency inferior in terms of thickness uniformity and quality can be seen.

In addition, the efficiency of the reaction gas is lower than that of the vertical type, and the economic efficiency of the thick film is not only lowered. In addition, the process by-products ( Maintenance is difficult due to many by-products).

In addition, the reaction gas has a convection phenomenon and a diffusion phenomenon, which prevents the laminar flow, resulting in a region in which the reacted gases are not deposited on the substrate P.

Conventional horizontal hydride vapor deposition reactor has a non-uniformity of the growth layer on the substrate (P) due to the non-uniform temperature of the susceptor (2), and can not change the gas velocity on the fixed substrate (P) surface optimum growth conditions There is a constraint on obtaining.

An object of the present invention is to provide a hydride vapor deposition reactor capable of forming a uniform film by forming the same growth conditions on a plurality of substrates.

Another object of the present invention is to form a film having a uniform thickness by removing only the process by-product generated in the center of the susceptor by spraying only one gas into the center of the susceptor.

Another object of the present invention is to improve the flow of gas generated in a region unnecessary for the reaction to obtain a laminar flow of gas over the entire susceptor.

In addition, the present invention is to facilitate the replacement of the solid source that is chemically reacted with the gas.

In order to achieve the above object, the hydride vapor deposition reactor according to the present invention includes a spraying plate for partitioning a reaction chamber sealed up and down with the outside, and an injecting portion communicates with a space by the spraying plate, respectively to inject a gas. And a gas pipe, wherein a solid source for generating a reaction gas is received through a source holder in the center portion of the susceptor, and the second gas pipe is disposed inside the source holder, so that the first and second gases are injected into the injection plate. It is characterized in that it is configured to react by joining in the lower space.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It must be interpreted to mean meanings and concepts.

As shown in FIG. 2, the hydride vapor deposition reactor according to the present invention includes a head 11 and a reaction chamber 10 which is isolated from the outside and maintains a vacuum state, and rotates inside the reaction chamber 10. The first gas and the first gas are formed to form a thick film (thick growth layer) on the susceptor 20, which is mounted on the susceptor 20, and the susceptor 20, which is mounted on the susceptor 20. And gas injection means 30 for injecting ammonia and hydrochloric acid gas into two gases, respectively.

The susceptor 20 is formed of a horizontal seating portion 21 on which the substrate P is seated and a rotating shaft 22 which is integrally formed at the center lower portion of the seating portion 21 and has a hollow inside. Inside the rotating shaft 22, a solid source 35 chemically reacting with the second gas is accommodated so as to be replaceable. The source holder 36 is installed inside the rotating shaft 22 to mount the solid source 35. The source holder 36 has a tubular structure with an open upper side, and a flange 36a that is seated on the seating portion 21 of the susceptor 20 is formed at the upper periphery.

The gas injection means 30 has a first gas pipe 31 for injecting a first gas (ammonia gas), a second gas pipe 32 for injecting a second gas (hydrochloric acid gas), and a plurality of injection holes 33a. It consists of the injection plate 33 and the cooling water flow path 34 through which cooling water is circulated.

The gas injection means 30 is provided integrally with the head portion 11 to replace the solid source 35 by opening only the head portion 11 upward and opening the source holder 36 when the solid source 35 is replaced. Can be.

The second gas pipe 32 is installed through the head portion 11 so that the second gas is injected into the center portion (part corresponding to the solid source 35) of the susceptor 20, and the inflow portion 32a into which the gas flows is introduced. ), A gas induction part 32b formed at the lower end of the inlet part 32a, and an injection part 32c formed in the lower part of the gas induction part 32b. The gas induction part 32b has a diameter larger than that of the inlet part 32a and is spaced apart from the upper opening of the source holder 36 by a predetermined distance (the distance at which gas can be injected around) so that the first gas is a solid source ( It prevents the inflow to the 35) side and guides the second gas injected through the injection part 32c to flow to the circumferential side (substrate P side) of the susceptor 20. The injection part 32c has an outer diameter that is smaller than the gas induction part 32b at a lower portion of the gas induction part 32b and can be spaced apart from the inner wall of the source holder 36 by a predetermined distance. It is tapered in shape.

The injection plate 33 is disposed above the susceptor 20 to partition the reaction chamber 10 into two spaces 13 and 14.

The first gas pipe 31 is installed so that the injection part 31a communicates with the first space 13 above the injection plate 33 while passing through the head part 11, and the second gas pipe 32 has a head part ( It is provided so that the injection part 32c may be arrange | positioned in the 2nd space 14 through 11) and the injection plate 33. As shown in FIG. That is, the gas injected from the first gas pipe 31 is injected through the injection hole 33a of the injection plate 33, and the gas injected from the second gas pipe 32 is not flowed back by the injection plate 33. Reaction with the first gas forms a film on the substrate P.

The cooling water flow path 34 is for controlling the temperature of the first and second gases and is partitioned by the partition 13 on the upper portion of the reaction chamber 10, and the cooling water is circulated along the inside thereof.

Induction coil 40 is installed to heat susceptor 20. The induction coil 40 is installed on the bottom of the susceptor 20 and the periphery of the source holder 36 to induce heating of the susceptor 20 while rotating together with the susceptor 200. Inducing the susceptor 20 By heating by heating method, it is easy to maintain constant temperature because the time of temperature rise and cooling is reduced and the temperature variation is very small.

The action of the hydride vapor deposition reactor according to the present invention is as follows.

When the operation of the reactor is started, a current is applied to the induction coil 40 to heat the susceptor 20 to form reaction conditions.

The first gas is injected into the first space 13 of the reaction chamber 10 through the first gas pipe 31 and then uniformly through the injection hole 33a of the injection plate 33 to the second space 14. The second gas is injected into the second space 14 through the second gas pipe 32. In this case, the first gas injected into the second space 14 may not penetrate into the source holder 36 by the gas induction part 32b of the second gas pipe 32. The second gas injected into the source holder 36 reacts with the solid source 35 to generate a reaction gas, and the reaction gas is guided by the gas induction part 32 to the circumferential side of the susceptor 20 (substrate). (P) side). That is, the first and second gases are less likely to react with each other until they reach the second space 14 in which the susceptor 20 is disposed.

As such, the ammonia gas and the reactant gas injected through the respective gas pipes 31 and 32 join in the second space 14 and recombine with the decomposed atoms again by pyrolysis, respectively, passing over the rotating susceptor 200. While deposited on the substrate (P).

During the thin film deposition process by the first and second gases, only the second gas pipe 32 is installed at a portion corresponding to the center portion of the susceptor 20, and thus only the second gas has no reaction at the center of the susceptor 20. 20) As it exits to the outside, it fills in the position of the insufficient second gas, reacts with the first gas, and deposits it on the substrate P. As a result, the gas concentration (mixing ratio of the first and second gases) on the plurality of substrates P seated on the susceptor 20 has an even distribution on all sides without biasing to one side, and the susceptor 20 In the center, no reaction takes place.

When the head 11 is lifted up when the solid source 35 is replaced, the head 11 and the gas injection means 30 are removed together to open the source holder 36, and the source holder 36 is a susceptor ( Close to the surface of 20), the solid source 35 can be easily replaced.

 As described above, according to the hydride vapor deposition reactor according to the present invention, the reaction is suppressed at the central portion of the rotating susceptor to maintain the same growth conditions on a plurality of substrates arranged at equal intervals over the entire region of the susceptor. Therefore, the thin film can be uniformly deposited, and the substrate can be positioned in a section where the reaction gas is in contact with the optimum reaction condition, thereby reducing the quality of the by-product, thereby producing a high quality thin film. Less process by-products result in increased productivity by reducing the time required to remove by-products for the next process.

In addition, since the gas pipe is close to the substrate and does not need to be unnecessarily long, clogging due to condensation of the process by-products on the inner wall of the reactor is minimized due to the excessive reaction.

While the invention has been described and illustrated in connection with a preferred embodiment for illustrating the principles of the invention, the invention is not limited to the configuration and operation as such is shown and described. Rather, it will be apparent to those skilled in the art that many changes and modifications to the present invention are possible without departing from the spirit and scope of the appended claims. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

Claims (3)

A reaction chamber 10 provided with a head portion 11 and maintaining a vacuum; A susceptor 20 rotatably installed in the reaction chamber and having a plurality of substrates P mounted thereon; Gas injection means (30) for injecting gas into the susceptor to form a film on the surface of the substrate; In the hydride vapor deposition reactor comprising a heating means for heating the susceptor, The susceptor is formed of a horizontal seating portion 21 on which the substrate is seated and a rotating shaft 22 formed in the lower center of the seating portion and having a hollow inside thereof. The gas injection means is formed under the head, and partitions the inside of the reaction chamber into upper and lower spaces 13 and 14 and has a plurality of injection holes 33a, and penetrates the head. The first gas pipe 31, the injection unit is in communication with the first space above the injection plate so that the first gas is injected through the injection hole of the injection plate 33 via the first space 13, A source holder 36 coupled to the inside of the rotating shaft of the susceptor and receiving a solid source 35 therein, and a lower injection part 32c is disposed inside the source holder while penetrating the center of the head part and the injection plate. And a second gas pipe (32) which is injected into the surface of the susceptor after the second gas passes through the inside of the source holder and reacts with the first gas. The gas induction part 32b of claim 1, wherein the second gas pipe penetrates through the injection plate and is spaced upward from the opening of the source holder in a lower portion of the inlet. And an injection part (32c) inserted into the lower portion of the gas induction part with a gap between the inner circumferential surface of the source holder and injecting gas into the source holder. The hydride vapor deposition reactor according to claim 1 or 2, wherein the heating means is an induction coil (40) surrounding the bottom of the susceptor and the rotating shaft.

Images