WO2011139039A2

WO2011139039A2 - Gas discharge unit, manufacturing method for the same, and substrate processing apparatus having the same

Info

Publication number: WO2011139039A2
Application number: PCT/KR2011/002996
Authority: WO
Inventors: Sun Hong Choi; Sung Rok Bae; Seung Ho Lee; Tae Wan Lee; Ho Chul Lee
Original assignee: Jusung Engineering Co., Ltd.
Priority date: 2010-05-06
Filing date: 2011-04-25
Publication date: 2011-11-10
Also published as: WO2011139039A3; KR20110123187A; TW201140656A

Abstract

A gas discharge unit of a substrate processing apparatus is disclosed. The gas discharge unit includes a flat plate shaped body, a plurality of gas injection holes formed in the body, and a reflection adjustor provided on a surface of the body in which the gas injection holes are formed, the reflection adjustor serving to reduce reflectivity of the surface of the body.

Description

GAS DISCHARGE UNIT, MANUFACTURING METHOD FOR THE SAME, AND SUBSTRATE PROCESSING APPARATUS HAVING THE SAME

The present invention relates to a substrate processing apparatus and more particularly, to a gas discharge unit of a substrate processing apparatus.

Conventionally, fabrication of semiconductor devices, flat panel displays, solar cells, etc. requires a series of processes including thin film deposition to deposit a particular material on a substrate, such as a wafer or glass, to form a thin film, photolithography to expose or cover a selected region of the thin film using a photoresist, and etching to remove the selected region of the thin film to obtain a desired thin film pattern.

Here, to prevent substrate contamination, most of the aforementioned processes are performed within a vacuum process chamber.

A substrate processing apparatus adopts a gas distribution device, such as, e.g., a gas discharge unit, to evenly distribute process gas within the entire process chamber, the process chamber internally providing a reaction space. In general, examples of methods for depositing a thin film on a substrate include Chemical Vapor Deposition (CVD) and Metal Organic Chemical Vapor Deposition (MOCVD).

Conventionally, the gas discharge unit to supply process gas into the process chamber has been made of stainless steel. A stainless steel product, however, exhibits high reflectivity due to a brilliant surface thereof. Thus, the stainless steel gas discharge unit may reflect heat to the surface of the substrate during a process, thereby changing a temperature of the substrate.

In addition, as the process progresses, the process gas and a target material may be deposited on the surface of the gas discharge unit, which may change the color of the surface of the gas discharge unit. When the color of the surface of the gas discharge unit is changed, thermal reflection and absorption at the surface of the gas discharge unit may also be changed. Therefore, the quantity of thermal energy transferred to the substrate may be changed and consequently, the temperature of the substrate may be changed.

Such a change in the temperature of the substrate may have a negative effect on substrate uniformity.

One object of the present invention devised to solve the problem lies in a gas discharge unit, which does not cause heat loss due to change in color thereof during a process, such as MOCVD, and a substrate processing apparatus having the same.

Another object of the present invention is to reduce time required for coating a gas discharge unit with respect to a substrate processing process, thereby reducing process time and target material consumption.

The object of the present invention can be achieved by providing a gas discharge unit of a substrate processing apparatus, including a flat plate shaped body, a plurality of gas injection holes formed in the body, and a reflection adjustor provided on a surface of the body in which the gas injection holes are formed, the reflection adjustor serving to reduce reflectivity of the surface of the body.

In accordance with another aspect of the present invention, there is provided a substrate processing apparatus including a chamber in which a substrate platform is provided, and a gas discharge unit provided at a lid of the chamber and including a body provided with a plurality of gas injection holes, a reflection adjustor being provided on a surface of the body in which the gas injection holes are formed and serving to reduce reflectivity of the surface of the body.

The substrate processing apparatus may further include a substrate entrance/exit unit provided at a lateral surface of the chamber, through which the substrates are introduced into or discharged from the chamber.

Here, the reflection adjustor may include at least one of a treated surface portion having a regular or irregular roughened surface and a reflection adjusting layer made of a reflection adjusting material to reduce the reflectivity.

The reflection adjusting material may contain at least one of Si, Zn and C.

Also, the reflection adjusting material may contain at least one of SiO₂, ZnO and SiC.

The treated surface portion may be formed by beading or sanding.

The reflection adjusting layer may have a thickness of 0.1㎛ to 1000㎛.

First process gas and second process gas are injected from the gas injection holes through different routes.

The gas injection holes may include a first nozzle and a second nozzle uniformly distributed in the body, and the first process gas may be injected through the first nozzle and the second process gas may be injected through the second nozzle.

The substrate platform may support a plurality of substrates coaxially arranged in a radial direction about the center thereof.

In accordance with a further aspect of the present invention, there is provided a method for manufacturing a gas discharge unit of a substrate processing apparatus, including forming a plurality of gas injection holes in a flat plate shaped body, and forming a reflection adjustor on a surface of the body in which the gas injection holes are formed, the reflection adjustor serving to reduce reflectivity of the surface of the body.

The formation of the reflection adjustor may include forming at least one of a treated surface portion having a regular or irregular roughened surface and a reflection adjusting layer made of a reflection adjusting material to reduce the reflectivity.

The reflection adjusting material may contain at least one of Si, Zn and C.

The reflection adjusting material may contain at least one of SiO₂, ZnO and SiC.

The formation of the reflection adjusting layer may include forming the reflection adjusting layer by at least one of chemical coating, sputtering, spraying, and arc ion plating.

Also, the formation of the reflection adjusting layer may further include baking the reflection adjusting layer formed by chemical coating.

The formation of the treated surface portion may include beading or sanding the surface of the body in which the gas injection holes are formed.

As described above, a gas discharge unit, a manufacturing method for the same, and a substrate processing apparatus having the same according to the present invention have the effects as follows.

Firstly, heat loss due to change in the color of a gas discharge unit during a process, such as, e.g., MOCVD, does not occur.

Secondly, time required for coating of the gas discharge unit during a substrate processing process is reduced, which reduces process time and target material consumption.

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.

In the drawings:

FIG. 1 illustrates a sectional view of one embodiment of a substrate processing apparatus according to the present invention.

FIG. 2 illustrates a perspective view of a gas discharge unit of FIG. 1.

FIGs. 3a to 3d illustrate sectional views of different embodiments of the gas discharge unit.

FIGs. 4a to 4d illustrate views of one embodiment of a manufacturing method of the gas discharge unit according to the present invention.

FIG. 5 illustrates a view of one embodiment of a substrate platform of FIG. 1.

FIG. 6 illustrates a view of another embodiment of the gas discharge unit of FIG. 1.

FIGs. 7 and 8 illustrate a detailed sectional view and an exploded perspective view of the gas discharge unit of FIG. 6.

FIG. 9a illustrates a graph showing the temperature of a conventional gas discharge unit during a process.

FIG. 9b illustrates a graph showing the temperature of the gas discharge unit according to the embodiment of the present invention, the gas discharge unit having a reflection adjustor provided at a stainless steel surface thereof.

FIG. 9c illustrates a graph showing the temperature tendency of a substrate platform depending on the presence/absence of the reflection adjustor of the gas discharge unit according to the embodiment of the present invention.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

In the drawings, the thicknesses or sizes of respective layers are exaggerated, omitted or schematically illustrated for clarity and convenience of description. Therefore, the sizes of respective elements do not wholly reflect actual sizes thereof.

FIG. 1 illustrates a sectional view of an embodiment of the substrate processing apparatus according to the present invention. Hereinafter, the substrate processing apparatus according to the embodiment of the present invention will be described with reference to FIG. 1.

A process chamber according to the present embodiment may be designed for use in the manufacture of semiconductor devices, flat panel displays, solar cells, etc. and may mainly be used to deposit a particular material on a substrate to form a thin film.

As illustrated, the substrate processing apparatus includes a process chamber 200 and a substrate entrance/exit unit 100, which come into surface contact with each other. The substrate entrance/exit unit 100 includes a housing 110, and a blade 130 movably placed in the housing 110 to open or close an opening perforated in the housing 110.

Here, the substrate entrance/exit unit 100 serves to selectively open or close process chamber(s), through which a substrate (wafer or glass) is introduced into or discharged from the process chamber(s). Of course, the substrate entrance/exit unit 100 may have another configuration except for the illustrated configuration.

The process chamber 200 includes a frame 210 and a chamber lid 220 to hermetically seal the top of the frame 210. Here, the frame 210 is made of aluminum, or the like. For example, the frame 210 may be formed by cutting a single aluminum block, by welding a plurality of aluminum sidewall and bottom plates to one another, or by bolting a plurality of aluminum sidewall and bottom plates to one another with O-rings interposed at boundaries thereof. In this case, of course, the O-rings or bolting serves to maintain the interior of the process chamber 200 at a vacuum pressure.

The chamber lid 220 may be made of the same material as the frame 210. As will be described hereinafter, the chamber lid 220 may also serve as a Radio Frequency (RF) electrode when a Radio Frequency (RF) power source is connected thereto.

A substrate platform 230 to support a substrate S seated thereon is provided in the frame 210. The frame 210 has a substrate entrance/exit opening perforated in a lateral surface thereof in contact with the substrate entrance/exit unit 100.

Here, a gas discharge unit 250 is connected to a lower surface of the chamber lid 220, and a gas feeding pipe 260 penetrates the center of the chamber lid 220. In addition, an RF power source 270 is connected to the center of the chamber lid 220 to apply RF power to the chamber lid 220.

After the substrate S is seated in the process chamber 200 having the above described configuration, a target material is injected via the gas discharge unit 260 and RF power is applied to the chamber lid 220, causing generation of plasma as a mixture of ions and active species. As the ions or active species are introduced into the substrate S, a certain process, such as thin film deposition or etching, is performed.

Then, the remaining target material or etching byproduct (hereinafter, referred to as a "residual substance" is moved from the periphery of the substrate S to below the substrate platform 230, thereby being discharged through an exhaust hole 280.

FIG. 2 illustrates a perspective view of the gas discharge unit of FIG. 1, and FIGs. 3a to 3d illustrate sectional views of different embodiments of the gas discharge unit. Hereinafter, the respective embodiments of the gas discharge unit according to the present invention will be described with reference to FIGs. 2 to 3d.

The gas discharge unit 250 may function to inject a target material, etc., and may be configured in such a manner that a plurality of gas injection holes 254 is perforated in a flat plate shaped body 252. Here, for convenience of illustration, FIG. 2 illustrates an inverted state of the gas discharge unit 250 within the substrate processing apparatus illustrated in FIG. 1.

A reflection adjustor 256 may be provided on a surface of the flat plate shaped body 252 and serve to reduce reflectivity of the surface of the body 252. More particularly, the reflection adjustor 256 may be formed on the surface of the body 252 exposed to the gas injected into the chamber 200.

Here, the reflection adjustor 256 may include at least one of a treated surface portion 256b and a reflection adjusting layer 256a. Here, the reflection adjusting layer 256a may be made of a reflection adjusting material which will be described hereinafter.

Specifically, the reflection adjustor 256 serves to maintain constant reflectivity and thermal absorption at the body surface of the gas discharge unit 250, a main material of which is stainless steel. The reflection adjustor 256 may be obtained by roughening the surface, or by coating the surface with the reflection adjusting material to reduce reflectivity of the surface.

In this case, the surface of the body 252, on which the reflection adjusting layer 256a is formed, may be black, and the reflection adjustor 256 may need not be provided inside the gas injection holes 254.

In the embodiment illustrated in FIG. 3a, the body 252 of the gas discharge unit 250 is provided with the plurality of gas injection holes 254, and the reflection adjusting layer 256a is formed on the surface of the body 252 where an exit through which, e.g., a target material is injected is located.

Here, the reflection adjusting material may contain at least one of Si, Zn and C and also, may contain any one of SiO₂, ZnO and SiC.

The above reflection adjusting materials are black or similar color and thus, may maintain constant reflectivity and thermal absorption at the surface of the gas discharge unit 250. Also, these reflection adjusting materials do not react with the target material within the process chamber 200.

In the embodiment of FIG. 3b, the body 252 of the gas discharge unit 250 is provided with the plurality of gas injection holes 254, and the treated surface portion 256b is formed on the surface of the body 252 where the exit through which the target material is injected is located.

As illustrated, the treated surface portion 256b may be a regular or irregular roughened portion. The treated surface portion 256b may be obtained by beading or sanding, which will be described hereinafter.

In the embodiment of FIG. 3c, the body 252 of the gas discharge unit 250 is provided with the plurality of gas injection holes 254, and the reflection adjusting layer 256a is formed on the surface of the body 252 where the exit through which the target material is injected is located. The reflection adjusting layer 256a has a roughened surface, i.e. the treated surface portion 256a.

In the embodiment of FIG. 3d, the treated surface portion 256b is formed on the body 252 of the gas discharge unit 250 provided with the plurality of gas injection holes 254, and the reflection adjusting layer 256a is formed on the treated surface portion 256b. Similar to the above description, the reflection adjusting material may contain any one of Si, SiO₂, ZnO and SiC, and the treated surface portion 256b may be obtained by beading or sanding. Also, a mass ratio of the above described materials may include Si or Zn of 33~35%, C of 11~13% and O of 43~45%.

The constituent material of the reflection adjusting layer 256a must not react with any material included in the process chamber during MOCVD, and must to withstand temperatures of 1000℃ or more. In addition, the constituent material must not remain powder having a negative effect on the process. For example, in the case of a GaN process, the reflection adjusting material must not react with H₂ and NH₃ at 1000℃ or more.

In the above described embodiments, the reflection adjusting layer 256a may have a thickness of 0.1~1000㎛. If the thickness of the reflection adjusting layer 256a is less than 0.1㎛, the reflection adjusting layer 256a substantially has no effect on thermal efficiency. On the other hand, if the thickness of the reflection adjusting layer 256a is greater than 1000㎛, the reflecting adjusting layer 256a may be easily peeled off, rather than enhancing thermal efficiency.

FIGs. 4a to 4d are views illustrating one embodiment of a manufacturing method of the gas discharge unit according to the present invention. Hereinafter, the manufacturing method of the gas discharge unit according to the embodiment of the present invention will be described with reference to FIGs. 4a to 4d.

First, as illustrated in FIG. 4a, the plurality of gas injection holes is perforated in the body 252 of the gas discharge unit. In this case, the gas injection holes may be initially formed in the stainless steel body 252.

Next, as illustrated in FIG. 4b, the surface of the body 252 provided with the gas injection holes 254 is roughened. In this case, the roughened surface may be obtained by beading or sanding. In FIG. 4b, the roughened surface is formed at a left partial region of the body 252.

Next, as illustrated in FIG. 4c, the reflection adjusting layer is formed on the surface of the body 252 provided with the gas injection holes 254 and the treated surface portion 256b, such as the roughened surface portion. In this case, the reflection adjusting material of the reflection adjusting layer may contain at least one of Si, Zn and C and also, may contain any one of SiO₂, ZnO and SiC.

Alternatively, in the reverse order of the above description of FIGs. 4b and 4c, the reflection adjusting layer may first be formed by coating and then, a surface of the reflection adjusting layer may be roughened by sanding or beading.

If it is difficult to directly coat the above described material due to a difference of thermal expansion coefficients between the stainless steel surface and the reflection adjusting layer, bond coating using Ni, Al, or the like may first be performed and thereafter, the reflection adjusting material may be coated.

The reflection adjusting layer may be formed by any one method selected from among chemical coating, sputtering, spraying, and arc ion plating.

First, chemical coating is a method of forming a chemical coating on a metal surface. Examples of chemical coating include phosphate coating, chrometry treatment, and coloring.

The chemically coated reflection adjusting material may be baked. In this case, a sufficient temperature at which to bake the reflection adjusting material may be greater than 500℃.

Sputtering is a method in which, if a voltage is applied to an inert gas, such as Ar, introduced into a vacuum chamber, sputtered atoms are ejected from a target material as a result of collision between Ar ions and the target material and are coated on an opposite surface of a substrate (shower head).

Arc ion plating is a method for coating the gas discharge unit with metal ions emitted while plasma is generated from a target material within a vacuum chamber maintaining an appropriate degree of vacuum when a voltage is applied to the target material.

As illustrated in FIG. 4d, the body 252 of the gas discharge unit 250 is provided with the gas injection holes 254 and the treated surface portion 256b and the reflection adjusting layer 256a are formed on the surface of the body 252. Alternatively, when attempting to form only one of the treated surface portion 256b and the reflection adjusting layer 256a as illustrated in FIGs. 3a and 3b, any one of the processes illustrated in FIGs. 4b and 4c may be omitted.

FIG. 5 is a view illustrating one embodiment of the substrate platform of FIG. 1.

As illustrated, the substrate platform 230 supports five susceptors 235, on each of which a single substrate S is seated, the five susceptors 235 being coaxially arranged in a radial direction. That is, a plurality of substrates S having a uniform size is seated on the substrate platform 230, and the number of the substrates S is not limited to five. In another embodiment, a single substrate may be seated on the single substrate platform 230.

FIG. 6 is a view illustrating another embodiment of the gas discharge unit of FIG. 1.

Although the same target material may be injected from the gas injection holes of the gas discharge unit, as illustrated, different target materials I, II and III may be supplied into the process chamber through different routes by the gas discharge unit 250. Specifically, at least two target materials I and II may be supplied into the process chamber through first gas injection holes, and the other target material III may be supplied into the process chamber through second gas injection holes.

FIGs. 7 and 8 are respectively a detailed sectional view and an exploded perspective view of the gas discharge unit of FIG. 6. Hereinafter, the embodiment in which target materials are supplied through different routes by the gas discharge unit will be described with reference to FIGs. 7 and 8.

In the present embodiment, the gas discharge unit is configured to supply a target material I (i.e. first process gas) and a target material II (i.e. second process gas). That is, the gas injection holes of the gas discharge unit include first gas injection holes and second gas injection holes to inject the different target materials I and II onto the substrates through different routes.

As illustrated, a first gas distributor 304 of a gas distribution device is secured to a chamber lid 300. A first space 330 is defined between the chamber lid 300 and the first gas distributor 304. The first space 330 serves to accommodate first process gas introduced through a first gas introduction pipe 304a.

The chamber lid 300 corresponding to the first gas distributor 304 is provided with an indented portion 318. A baffle 304c is installed between the indented portion 318 and the first space 330 defined by a first housing 304b. The baffle 304c includes a plate and a plurality of supply holes 320 perforated in the plate. The baffle 304c functions to uniformly supply the first process gas introduced through the first gas introduction pipe 304a and the indented portion 318 into the first space 330.

Here, to uniformly supply the first process gas into the first space 330, it is preferable that any one of the plurality of supply holes 320 do not directly communicate with the first gas introduction pipe 340a. Specifically, the baffle 304c acts to intercept the first process gas introduced through the first gas introduction pipe 304a to allow the first process gas to be accommodated in the indented portion 318 and thereafter, the first process gas is supplied into the first space 330 through the plurality of supply holes 320.

The first gas distributor 304 may be made of aluminum having high workability. In this case, an aluminum block may be used to form the first space 330 in which the first process gas is accommodated. A plurality of passage holes 304d for passage of the first process gas may be perforated in the bottom of the aluminum block.

Instead of using the aluminum block, the first gas distributor 304 may be formed by welding aluminum sidewall and bottom plates to one another and perforating holes in the aluminum bottom plate. A sidewall of the first housing 304b has at least a thickness to cover a buffer space 306c defined in a second housing 306b of a second gas distributor 306.

The sidewall of the first housing 304b with a sufficient thickness to cover the buffer space 306c is provided so that a second gas introduction pipe 306a connected to the buffer space 306c is introduced through the chamber lid 300 and the sidewall of the first housing 304b. Thus, the thickness of the sidewall of the first housing 304b is preferably equal to the sum of a thickness of a sidewall of the second housing 306b and a width of the buffer space 306c.

After aligning the plurality of first passage holes 304d of the first gas distributor 304 with a plurality of second passage holes 306d of the second gas distributor 306, the second gas distributor 306 is coupled to the first gas distributor 304.

The second gas distributor 306 is made of aluminum having high workability. The plurality of second passage holes 306d is vertically perforated in an aluminum block, and regions between opposite sides of the aluminum block and the plurality of second passage holes 306d are cut to define the buffer space 306c and a second space 332 in which a second process gas is accommodated. Then, a plurality of third passage holes 306e is perforated between the respective second passage holes 306d.

A third gas distributor 308 is made of stainless steel or aluminum having high heat resistance and wear resistance. A third housing 308a of the third gas distributor 308 defines a third space 334. The third gas distributor 308 is coupled to the second gas distributor 306 such that the plurality of second and third passage holes 306d and 306e of the second gas distributor 306 respectively communicates with a plurality of first and

second nozzles

308b and 308c of the third gas distributor 308.

The first process gas is injected through the first nozzles 308b, and the second process gas is injected through the second nozzles 308c. The first nozzles 308b and the second nozzles 308c are uniformly distributed throughout the third gas distributor 308.

Thus, the first process gas and the second process gas are injected toward the substrate platform through the plurality of second and third passage holes 306d and 306e and the plurality of first and

second nozzles

308b and 308c under a hermetically sealed state.

In the present embodiment, the first process gas is introduced into the first gas distributor 304 to pass through the first gas distributor 304, and the second process gas is introduced into the second gas distributor 306 to pass through the second gas distributor 306. The first process gas and the second process gas are injected toward the substrate platform by the third gas distributor 308. That is, the first and

second nozzles

308b and 308c of the third gas distributor 308 serve as gas injection holes.

Assuming that at least two target materials are injected through the first gas injection holes, a target material having a higher dissolution temperature than the average of dissolution temperatures of the at least two target materials, can be injected toward the substrate(s) through the second gas injection holes.

FIGs. 9a to 9c are views illustrating effects of the gas discharge unit and the substrate processing apparatus according to the present invention as compared to those of the related art. Hereinafter, the effects of the gas discharge unit and the substrate processing apparatus according to the embodiment of the present invention will be described with reference to FIGs. 9a to 9c.

FIG. 9a is a graph showing the temperature of a conventional gas discharge unit during a process. As illustrated, the conventional gas discharge unit requires time over 30 minutes to coat and stabilize the surface thereof, and a temperature difference between t2 and t1 is about 10℃, which means that the temperature of the gas discharge unit increases by about 10℃.

FIG. 9b is a graph showing the temperature of the gas discharge unit according to the embodiment of the present invention, the gas discharge unit having the reflection adjustor provided at the stainless steel surface thereof. As illustrated, the temperature of the surface of gas discharge unit is stabilized and is less affected by deposition of a target material and gas within the chamber. Also, a temperature difference between t4 and t3 is about 1℃, which means that the temperature change of the gas discharge unit is slight.

FIG. 9c is a graph showing the temperature tendency of the substrate platform depending on the presence/absence of the reflection adjustor of the gas discharge unit according to the present invention. As can be appreciated from the illustration, the process chamber using the gas discharge unit provided with the reflection adjustor provides uniform temperature distribution throughout the substrate platform, whereas the gas discharge unit having no reflection adjustor exhibits significant temperature change at the edge of the substrate platform.

Various embodiments have been described in the best mode for carrying out the invention.

The present invention provides a gas discharge unit capable of stabilizing a temperature thereof without heat loss, a manufacturing method for the same, and a substrate processing apparatus having the same, which can reduce process time and target material consumption.

The features, structures and effects illustrated in the above embodiments may be included in at least one embodiment of the present invention but are not limited to one embodiment. Further, those skilled in the art will appreciate that various combinations and modifications of the features, structures and effects illustrated in the respective embodiments are possible. Therefore, it will be understood that these combinations and modifications are covered by the scope of the invention.

Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. For example, the respective elements described in detail in the embodiments may be modified. Further, it will be understood that differences relating to these modifications, additions and substitutions are covered by the scope of the invention defined in the accompanying claims.

Claims

A gas discharge unit of a substrate processing apparatus, comprising:

a flat plate shaped body;

a plurality of gas injection holes formed in the body; and

a reflection adjustor provided on a surface of the body in which the gas injection holes are formed, the reflection adjustor serving to reduce reflectivity of the surface of the body.
The gas discharge unit according to claim 1, wherein the reflection adjustor includes at least one of a treated surface portion having a regular or irregular roughened surface and a reflection adjusting layer made of a reflection adjusting material to reduce the reflectivity.
The gas discharge unit according to claim 2, wherein the reflection adjusting material contains at least one of Si, Zn and C.
The gas discharge unit according to claim 2, wherein the reflection adjusting material contains at least one of SiO₂, ZnO and SiC.
The gas discharge unit according to claim 2, wherein the treated surface portion is formed by beading or sanding.
The gas discharge unit according to claim 2, wherein the reflection adjusting layer has a thickness of 0.1㎛ to 1000㎛.
The gas discharge unit according to claim 1, wherein first process gas and second process gas are injected from the gas injection holes through different routes.
The gas discharge unit according to claim 7,

wherein the gas injection holes include a first nozzle and a second nozzle uniformly distributed in the body, and

wherein the first process gas is injected through the first nozzle and the second process gas is injected through the second nozzle.
A method for manufacturing a gas discharge unit of a substrate processing apparatus, comprising:

forming a plurality of gas injection holes in a flat plate shaped body; and

forming a reflection adjustor on a surface of the body in which the gas injection holes are formed, the reflection adjustor serving to reduce reflectivity of the surface of the body.
The method according to claim 9, wherein the formation of the reflection adjustor includes forming at least one of a treated surface portion having a regular or irregular roughened surface and a reflection adjusting layer made of a reflection adjusting material to reduce the reflectivity.
The method according to claim 10, wherein the reflection adjusting material contains at least one of Si, Zn and C.
The method according to claim 10, wherein the reflection adjusting material contains at least one of SiO₂, ZnO and SiC.
The method according to claim 10, wherein the formation of the reflection adjusting layer includes forming the reflection adjusting layer by at least one of chemical coating, sputtering, spraying, and arc ion plating.
The method according to claim 13, wherein the formation of the reflection adjusting layer further includes baking the reflection adjusting layer formed by chemical coating.
The method according to claim 10, wherein the formation of the treated surface portion includes beading or sanding the surface of the body in which the gas injection holes are formed.
A substrate processing apparatus comprising:

a chamber in which a substrate platform is provided; and

a gas discharge unit provided at a lid of the chamber and including a body provided with a plurality of gas injection holes and a reflection adjustor being provided on a surface of the body in which the gas injection holes are formed and serving to reduce reflectivity of the surface of the body.
The substrate processing apparatus according to claim 16, wherein the reflection adjustor includes at least one of a treated surface portion having a regular or irregular roughened surface and a reflection adjusting layer made of a reflection adjusting material to reduce the reflectivity.
The substrate processing apparatus according to claim 17, wherein the reflection adjusting material contains at least one of Si, Zn and C.
The substrate processing apparatus according to claim 17, wherein the reflection adjusting material contains at least one of SiO₂, ZnO and SiC.
The substrate processing apparatus according to claim 17, wherein the treated surface portion is formed by beading or sanding.
The substrate processing apparatus according to claim 17, wherein the reflection adjusting layer has a thickness of 0.1㎛ to 1000㎛.
The substrate processing apparatus according to claim 16, wherein the substrate platform supports a plurality of substrates arranged in a radial direction about the center thereof.
The substrate processing apparatus according to claim 16, wherein first process gas and second process gas are injected from the gas injection holes through different routes.
The substrate processing apparatus according to claim 23,

wherein the gas injection holes include a first nozzle and a second nozzle uniformly distributed in the body, and

wherein the first process gas is injected through the first nozzle and the second process gas is injected through the second nozzle.
The substrate processing apparatus according to any one of claims 16 to 24, further comprising a substrate entrance/exit unit provided at a lateral surface of the chamber, through which the substrates are introduced into or discharged from the chamber.