The present application claims priority from Korean Patent Application Number 10-2012-0104309 filed on Sep. 20, 2012, the entire contents of which are incorporated herein for all purposes by this reference.
1. Field of the Invention
The present invention relates to a gas injector and an injector pipe used for the same, and more particularly, to a gas injector which injects gas to a substrate during chemical vapor deposition (CVD) and an injector pipe used for the same.
2. Description of Related Art
Chemical vapor deposition (CVD) as well as physical vapor deposition (PVD) is a typical deposition method of forming a deposited film on a substrate.
CVD forms an intended deposition film on a substrate by heating and gasifying a source material that corresponds to a raw material and then feeding the gasified source material into a deposition chamber. In this process, energy required for forming the deposited film by heating the substrate to a certain temperature is supplied.
CVD has advantages in that the distribution and concentration of impurities can be controlled, the thickness of a film can be controlled (several to tens of nanometers), a deposited film can be formed on an insulator, and a substrate can be etched in situ.
In particular, atmospheric pressure chemical vapor deposition (APCVD) can significantly reduce the fabrication cost of products in mass production by, for example, enabling a continuous deposition process and precluding the use of a vacuum pump. In addition, another advantage is that a large area can be coated by APCVD.
In APCVD, important variables that are basically considered in order to produce a uniform deposited film may include the uniformity of the temperature of the substrate, the stability of the flow of a reaction substance, and the like.
As shown in
As shown in
However, when the holes of the injector pipe 40 are formed in this fashion, the flow of the reaction gas injected from the gas injector becomes non-uniform.
As shown in
This can also be confirmed from the graph shown in
When the gas is injected at non-uniform velocity, a non-uniform film is deposited on the substrate and the quality of the film is lowered, which is problematic.
The information disclosed in the Background of the Invention section is provided only for better understanding of the background of the invention, and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.
Various aspects of the present invention provide a gas injector which can inject at a uniform velocity and an injector pipe used for the same.
In an aspect of the present invention, provided is a gas injector that includes: a body; a gas flow path formed inside the body, the gas flow path extending from one end to the other end in a lengthwise direction of the body; a blade formed inside the body and connected to the gas flow path so as to inject gas; and an injector pipe inserted into the gas flow path. The injector pipe receives the gas from the gas supply, and distributes the gas through a plurality of holes to the gas flow path. The plurality of holes of the injector pipe include a plurality of first holes and a plurality of second holes which are formed along two parallel lines extending in the lengthwise direction of the injector pipe, the first holes alternating with the second holes.
According to an exemplary embodiment of the present invention, the central angle defined by the plurality of first holes and the plurality of second holes about the center of the injector pipe may range from 0 to 120°.
The distance between the first holes and the distance between the second holes may decrease in the direction away from the gas supply. It is preferred that the distance between the first holes and the distance between the second holes decrease by a predetermined size in the direction away from the gas supply, the predetermined size ranging from 0.02 to 0.06 mm.
The injector pipe may have the plurality of first holes and the plurality of second holes in the upper side that is opposite the lower side that faces the blade. (Here, the upper side and the lower side do not indicate the absolute positional relationship but a relative positional relationship. Therefore, it is possible to name the side that faces the blade as the upper side and its opposite side as the lower side.)
The total number of the first holes and the second holes may satisfy the formula:
⅓*π*Rin2<nA<⅔*π*Rin2,
where n is the total number of the first holes and the second holes, Rin is an inner diameter of the injector pipe, and A is the cross-sectional area of the first and second holes.
The gas flow path may include a plurality of gas flow paths formed inside the body. The blade may include a plurality of blades each of which is connected to a corresponding gas flow path of the plurality of gas flow paths. The injector pipe may include a plurality of injector pipes each of which is inserted into a corresponding gas flow path of the plurality of gas flow paths.
The gas injector may further include a temperature controller which controls the temperature of the gas.
In another aspect of the present invention, provided is an injector pipe which receives gas from a gas supply and distributes the gas through a plurality of holes. The plurality of holes include a plurality of first holes and a plurality of second holes which are formed along two parallel lines extending in a longitudinal direction of the injector pipe, the first holes alternating with the second holes.
According to an exemplary embodiment of the present invention, the central angle defined by the plurality of first holes and the plurality of second holes about the center of the injector pipe may range from 0 to 120°.
The distance between the first holes and the distance between the second holes may decrease in the direction away from the gas supply.
The total number of the first holes and the second holes may satisfy the formula:
⅓*π*Rin2<nA<⅔*π*Rin2,
where n is the total number of the first holes and the second holes, Rin is an inner diameter of the injector pipe, and A is the cross-sectional area of the first and second holes.
According to embodiments of the present invention, since a plurality of first holes and a plurality of second holes are formed along two parallel lines on the injector pipe such that the first holes alternate with the second holes, it is possible to uniformize the flow rate of gas injected from the gas injector and deposit a uniform film on a substrate.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from, or are set forth in greater detail in the accompanying drawings, which are incorporated herein, and in the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
Reference will now be made in detail to a gas injector and an injector pipe used for the same according to the present invention, embodiments of which are illustrated in the accompanying drawings and described below, so that a person having ordinary skill in the art to which the present invention relates can easily put the present invention into practice.
Throughout this document, reference should be made to the drawings, in which the same reference numerals and signs are used throughout the different drawings to designate the same or similar components. In the following description of the present invention, detailed descriptions of known functions and components incorporated herein will be omitted when they may make the subject matter of the present invention unclear.
Referring to
The body 100 forms the contour of the gas injector, and can be implemented as a block having a rectangular parallelepiped shape.
The body 100 is positioned in the upper part of a chamber in which a deposition process is carried out, and a substrate on which a film is to be deposited is positioned below the body 100.
The gas flow path 200 is formed inside the body 100, and extends from one end to the other end of the body 100 in the lengthwise direction of the body 100. The injector pipe 400 is inserted into the glass flow path 200, and the gas flow path 200 allows gas distributed from the injector pipe 400 to flow toward the blade 300.
One end of the gas flow path 200 is closed. In addition, a seal is provided between the other end of the gas flow path 200 through which the injector pipe 400 is inserted and the injector pipe 400 such that the gas does not leak.
It is preferred that the gas flow path 200 be cylindrical.
The blade 300 is formed inside the body 100, and is connected to the gas flow path 200. The blade 300 is configured such that it injects the gas from the gas flow path 200 toward the substrate.
The gas that has been injected to the substrate through the blade 300 forms a deposited film on the substrate that is positioned inside the chamber.
The injector pipe 400 is inserted into the gas flow path 200, and is configured such that it distributes the gas supplied from a gas supply (not shown) to a plurality of gas flow paths 200 through a plurality of holes formed in the injector pipe 400. Here, it is possible to control the flow of the gas and the flow rate of the gas by adjusting the size, positions of the holes and the distance between the holes.
The outer circumference of the injector pipe 400 and the inner circumference of the gas flow path 200 are distanced from each other, thereby forming a space therebetween through which the gas distributed from the injector flows to the blade 300.
Referring to
As such, the plurality of first holes 401 and the plurality of second holes 402 are formed along the two parallel lines such that the first holes 401 alternate with the second holes 402. It is therefore possible to uniformize the flow rate of the gas injected through the blade 300, whereby a uniform film can be deposited on the substrate.
The central angle defined by the plurality of first holes 401 and the plurality of second holes 402 about the center of the injector pipe 400 (i.e. the angle defined by the line that connects the plurality of first holes to the center of the injector pipe and the line that connects the plurality of the second holes to the center of the injector pipe) is smaller than 180°. As shown in
In addition, it is preferred that the distance between the first holes 401 decrease in the direction away from the gas supply. More preferably, the distance between the first holes 401 decreases by a certain size in the direction away from the gas supply. Here, the certain size ranges from 0.02 to 0.06 mm. In addition, the distance between the first holes 401 and the distance between the second holes 402 can decrease in arithmetic progression or progression of differences.
In addition, it is preferred that the total number of the first holes 401 and the second holes 402 according to the present invention be set to satisfy the following formula:
⅓*π*Rin2<nA<⅔*π*Rin2,
where n is the total number of the first holes and the second holes, Rin is the inner diameter of the injector pipe, and A is a cross-sectional area of the first and second holes.
It is possible to calculate the distance between the holes using this formula.
In addition, the injector pipe can have the plurality of first holes 401 and the plurality of second holes 402 in the upper side that is opposite the lower side that faces the blade 300. Consequently, after the gas distributed from the injector pipe has flown along the inside of the gas flow path 200 for a certain time, it can be injected through the blade 300 toward the substrate, thereby reducing the flow rate of the gas more or less. It is therefore possible to improve the efficiency at which the gas is deposited on the substrate and the uniformity of the film that is deposited on the substrate. It addition, it is possible to increase the straightness of the gas injected from the blade 300.
The injector pipe 400 according to the present invention can be replaced. That is, when another injector pipe having a different hole size or different distance between the holes is required to be used or some holes of the injector pipe are closed, it is possible to separate only the injector pipe from the gas injector and put a new injector pipe in place.
In addition,
In the injector pipe 400 used in the computational fluid dynamics simulations shown in
As shown in
Table 1 presents a computational fluid dynamics simulation performed on the differences (cm/s) between the maximum flow rate and the minimum flow rate of gas injected through the blade, in which the simulation is performed using ANSYS Fluent by setting the distance d between the line of first holes 401 and the line of second holes 402 to 7 mm, varying the positions of the first holes 401 and the second holes 402, and varying the reduced size of the distance between the first holes 401 and between the second holes 402.
Referring to Table 1 and
In addition, the gas injector according to the present invention can further include a temperature controller (not shown) which improves deposition efficiency by controlling the temperature of gas that is injected.
The temperature controller (not shown) can control the temperature of gas that is injected to the substrate by circulating liquid or gas through the inside of the gas injector.
Referring to
When several kinds of gases are required to deposit a film on a substrate, individual gases can be injected to the substrate by being separated from each other through the plurality of gas flow paths 210 and 220, the blades 310 and 320 and the injector pipes 410 and 420 so that the gases neither prematurely mix nor react with each other inside the gas injector.
This can consequently help the gases injected from the gas injector react perfectly, efficiently and uniformly on the substrate, thereby improving the quality of the film deposited on the substrate.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented with respect to the drawings. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible for a person having ordinary skill in the art in light of the above teachings.
It is intended therefore that the scope of the present invention not be limited to the foregoing embodiments, but be defined by the Claims appended hereto and their equivalents.
Number | Date | Country | Kind |
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10-2012-0104309 | Sep 2012 | KR | national |