KR20230131558A - Gas supply apparatus - Google Patents

Abstract

The gas supply device includes a cleaning gas supply source that supplies a cleaning gas, a process gas supply source that supplies a process gas, a first flow path through which the cleaning gas flows, and is installed within the first flow path to open and close the first flow path. A gate valve that passes or blocks the cleaning gas, a second flow path that flows the process gas and joins the first flow path downstream of the gate valve, and a cleaning gas or the process gas that has passed through the gate valve. It consists of a shower head unit that sprays into the chamber, and a purge gas injection structure that sprays purge gas adjacent to the lower surface of the gate valve to prevent deposition of the process gas on the lower surface of the gate valve.

Description

Gas supply apparatus {Gas supply apparatus}

The present invention relates to a substrate processing device for depositing, etching, or cleaning a thin film on a substrate, and particularly to a gas supply device for spraying a cleaning gas and/or a process gas on the substrate.

In general, thin film deposition methods for depositing a thin film by supplying a reaction gas to a substrate include atomic layer deposition (ALD) and chemical vapor deposition (CVD). The atomic layer thin film deposition method is a method of adsorbing and depositing on a substrate by alternately supplying and purging a reaction gas to the substrate, and the chemical vapor deposition method is a method of depositing on a substrate by simultaneously spraying reaction gases.

Semiconductor equipment that performs this thin film deposition method includes, for example, a process chamber having a heater member for mounting a semiconductor wafer (hereinafter referred to as a wafer) therein, and supplying a process gas toward the wafer surface provided opposite the heater member. It is equipped with a gas supply device that operates. In this gas supply device, a gas flow path may be formed so that multiple types of process gases do not mix with each other and are spread horizontally and uniformly supplied to the wafer surface.

Additionally, the gas supply device generally uses a remote plasma method for in-situ cleaning. The remote plasma method is a technology that cleans deposition materials inside the process chamber by supplying a cleaning gas excited by plasma into the process chamber. Specifically, during cleaning, the gate valve opens and plasma-excited cleaning gas is supplied into the chamber, and during the deposition process, the gate valve closes and process gas is supplied through the process gas flow path joining at a point downstream of the gate valve. The deposition process proceeds.

However, since the gate valve is in a closed state during the deposition process, a problem occurs in which process gas is unnecessarily deposited on the lower surface of the gate valve while depositing the wafer. In this way, if foreign substances are deposited on the bottom of the gate valve, not only may the operation of the gate valve itself be impaired, but the foreign substances may later separate and fall, blocking part of the flow path connected to the shower head unit or damaging the deposited wafer. Contamination problems may also occur.

U.S. Patent Publication No. 2011-0126764 (published on June 2, 2011)

The technical problem to be achieved by the present invention is to prevent the phenomenon of deposition of the lower surface of the gate valve during the deposition process by spraying a purge gas near the lower surface of the gate valve used in semiconductor processing equipment having a remote plasma device for on-site cleaning. will be.

Another technical problem to be achieved by the present invention is to provide a more effective injection structure and injection conditions to prevent deposition on the bottom of the gate valve.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

A gas supply device according to an embodiment of the present invention for achieving the above technical problem includes a cleaning gas source that supplies cleaning gas; a process gas source supplying process gas; a first flow path through which the cleaning gas flows; A gate valve installed in the first flow path to allow or block the cleaning gas by opening and closing the first flow path; a second flow path flowing the process gas and joining the first flow path downstream of the gate valve; and a shower head unit that sprays the cleaning gas or the process gas that has passed through the gate valve into the chamber, wherein the purge gas is sprayed adjacent to the lower surface of the gate valve, thereby removing the lower surface of the gate valve by the process gas. It further includes a purge gas injection structure to prevent deposition.

The process gas is supplied when the gate valve is closed and is injected into the chamber through the shower head unit.

The purge gas is injected to the lower surface of the gate valve when the gate valve is closed.

The gas supply device further includes a purge gas source that supplies the purge gas to the purge gas injection structure, and the purge gas injection structure is formed in a direction surrounding the first flow path near the lower surface of the gate valve. gas supply ring; a third flow path that flows the purge gas from the purge gas source to the gas supply ring; and a plurality of injection holes that communicate with the gas supply ring and spray the purge gas flowing into the gas supply ring adjacent to the lower surface of the gate valve.

The cross-sectional diameter of the gas supply ring is larger than the diameter of the third flow path.

The plurality of injection holes are evenly disposed along the circumferential direction of the gas supply ring.

The plurality of injection holes are arranged along the circumferential direction of the gas supply ring, and are arranged so that the gap between the injection holes on the side farther from the third flow path is tighter than the gap between the third flow path and the injection holes on the closer side. do.

The plurality of injection holes are arranged to be inclined upward from the gas supply ring toward the lower surface of the gate valve based on the horizontal direction.

The inclined angle satisfies the range of 30° to 45°.

Each of the plurality of injection holes includes a plurality of sub-injection holes spaced apart in the vertical direction, and the plurality of sub-injection holes extend upward from the gas supply ring toward the lower surface of the gate valve based on the horizontal direction. It is placed at an angle.

The diameter of the plurality of sub-injection holes becomes larger as the plurality of sub-injection holes are positioned lower in the vertical direction.

The angle at which the plurality of sub-injection holes are inclined upward becomes larger as the plurality of sub-injection holes are positioned lower in the vertical direction.

According to the gas supply device used in the thin film deposition process according to the present invention, various problems due to the generation of foreign substances can be prevented by preventing deposition on the lower surface of the gate valve.

In addition, according to the gas supply device used in the thin film deposition process according to the present invention, by optimizing the injection conditions of the purge gas to prevent deposition of the gate valve, it is possible to provide a sufficient deposition prevention effect while minimizing the supply flow rate of the purge gas. there is.

Figure 1 is a front view showing a gas supply device according to an embodiment of the present invention.
FIG. 2 is a longitudinal cross-sectional view of the gas supply device of FIG. 1 cut in the longitudinal direction.
FIG. 3A is a longitudinal cross-sectional view of a purge gas injection structure according to an embodiment of the present invention, shown by enlarging area A of FIG. 2.
FIG. 3B is a cross-sectional view taken along line B-B' of FIG. 3A.
FIG. 4 is a longitudinal cross-sectional view of a purge gas injection structure according to another embodiment of the present invention, shown by enlarging area A of FIG. 2.
FIG. 5 is a longitudinal cross-sectional view of a purge gas injection structure according to another embodiment of the present invention, shown by enlarging area A of FIG. 2.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other elements in addition to the mentioned elements.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a front view showing a gas supply device 100 according to an embodiment of the present invention. Referring to FIG. 1, the gas supply device 100 includes a cleaning gas source 11 that supplies a cleaning gas, a process gas source 12 that supplies a process gas, and a purge gas source 13 that supplies a purge gas. ) and a shower head unit 40.

The cleaning gas may be a gas excited by plasma according to a remote plasma method for on-site cleaning, and the process gas may include a source gas and a reactant gas. Additionally, the purge gas may be an inert gas with low reactivity that is injected to block the inflow of gas in a specific direction.

The cleaning gas, the process gas, and the purge gas may be supplied from respective supply sources 11, 12, and 13 through respective supply pipes 21, 22, and 23.

The shower head unit 40 has a function of evenly spraying cleaning gas or the process gas onto wafers (not shown) placed in a process chamber (not shown) located below. In particular, the shower head unit 40 supplies process gas to the wafer in the process mode, and supplies cleaning gas to the wafer in the cleaning mode.

FIG. 2 is a longitudinal cross-sectional view of the gas supply device 100 of FIG. 1 cut in the longitudinal direction. As shown in FIG. 2, the cleaning gas supplied from the cleaning gas source 11 may be supplied to the shower head unit 40 through the first flow path 31 in the first supply pipe 21. At this time, a gate valve 50 is installed at a point on the upstream side of the first flow path 31. The gate valve 50 has a function of allowing the cleaning gas to pass through or blocking it by opening and closing the first flow path 31.

Meanwhile, the process gas supplied from the process gas source 12 may be supplied to the first flow path 31 through the second flow path 32 in the second supply pipe 22. At this time, the second flow path 32 joins the first flow path 31 at a position downstream of the gate valve 50. The process gas may be supplied when the gate valve 50 is closed and injected into the process chamber through the shower head unit 40. On the other hand, the cleaning gas may be supplied when the gate valve 50 is open and injected into the process chamber through the shower head unit 40. Of course, when supplying such cleaning gas, the supply of process gas must be blocked through a separate valve device.

The shower head unit 40 supplies the cleaning gas or process gas supplied through the common first flow path 31 into the lower process chamber. Specifically, the shower head unit 40 may be composed of a combination of an inlet port block 41, a diffusion block 43, and a spray nozzle 45. The lower end of the first flow path 31 is coupled to the inlet port block 41, and the lower end of the first flow path 31 communicates with the diffusion area 16 of the diffusion block 43. The gas supplied through the first flow path 31 diffuses from the center outward by the diffusion region 16. The gas diffused outward in this way collects in the buffer space 17 between the diffusion block 43 and the injection nozzle 45 and is then finally sprayed downward through the plurality of nozzle holes 18 formed in the injection nozzle 45. do.

According to one embodiment of the present invention, in order to prevent deposition on the lower surface of the gate valve 50 when the process gas is supplied with the gate valve 50 closed, a purge is applied near the lower surface of the gate valve 50. Gas is sprayed. To this end, the purge gas source 13 and a point near the lower surface of the gate valve 50 are connected through a third flow path 23 formed by the supply pipe 23.

As such, the detailed configuration for supplying purge gas near the lower surface of the gate valve 50 will be described in more detail with reference to FIGS. 3A to 5 described later.

FIG. 3A is a longitudinal cross-sectional view of the purge gas injection structure 70a according to an embodiment of the present invention, shown by enlarging area A of FIG. 2, and FIG. 3B is a longitudinal cross-sectional view taken along line B-B' of FIG. 3A. This is a cross-sectional view of the purge gas injection structure 70a.

The purge gas injection structure 70a is adjacent to the lower surface 52 of the gate valve 50 when the gate valve 50 is closed and the process gas is supplied through the second flow path 32. By spraying, deposition of the process gas on the lower surface of the gate valve is prevented.

Specifically, the purge gas injection structure 70a includes a gas supply ring 75a formed in a direction surrounding the first flow path 31 near the lower surface 52 of the gate valve 50, and the purge gas injection structure 70a. A third flow path 33 that allows the purge gas from the gas source 13 to flow into the gas supply ring 75a, and a purge that communicates with the gas supply ring 75a and flows into the gas supply ring 75a. It may be composed of a plurality of injection holes 71a that inject gas adjacent to the lower surface 52 of the gate valve 50.

At this time, it is preferable that the cross-sectional diameter of the gas supply ring 75a is designed to be significantly larger than the diameter of the third flow path 33 so as to have sufficient buffering capacity.

Additionally, as shown in FIG. 3B, the plurality of injection holes 71a may be evenly disposed along the circumferential direction of the gas supply ring 75a. However, the present invention is not limited to this and a plurality of injection holes 71a may be arranged unevenly along the circumferential direction. For example, it may be arranged so that the spacing between the injection holes 71a on the far side from the third flow path 33 is tighter than the spacing between the third flow path 33 and the injection holes 71a on the closer side. possible. In the case of equal arrangement, a problem may arise where the injection pressure at the injection hole (71a) near the third flow path 33, which is the entryway of the purge gas, is higher than the injection pressure at the injection hole (71a) located on the opposite side in the circumferential direction. , this problem can be alleviated through this uneven arrangement.

However, as shown in FIG. 3A, if the diameter of the first flow path 31 is d, the radius of the injection hole 71a is r, and the number of injection holes 71a is n, the first flow path ( The flow rate (Q) of purge gas reaching the center of 31) can be calculated as follows in Equation 1.

[Equation 1]

The flow rate (Q) of the purge gas for the deposition prevention effect on the lower surface 52 of the gate valve 50, that is, the curtain effect, is ideally calculated as in Equation 1 above. However, since pumping of the process gas occurs on the downstream side of the first flow path 31, the purge gas may also be drawn downward. Accordingly, even if the purge gas is injected horizontally, the purge gas is directed somewhat downward near the center of the first flow path 31. In this case, since the purge effect is weakened in the central area of the first flow path 31, a larger flow rate of purge gas is required to compensate for this, which may have a negative impact not only on energy loss due to waste of purge gas but also on the overall process. there is.

Therefore, in order to solve the problem of the purge gas flowing downward in the central area of the first passage 31, where such a problem may occur, it is necessary to increase the direction of the injection hole 71a upward to some extent. The question is how much upward angle (θ) is appropriate, and this upward angle (θ) can be obtained through Equation 2 below.

[Equation 2]

Here, d is the diameter of the first flow path 31 as described above, and k is the distance from the injection hole 71 to the lower surface 52 of the gate valve 50. For a more detailed explanation of Equation 2, refer to Figure 4 below.

FIG. 4 is a longitudinal cross-sectional view of a purge gas injection structure 70b according to another embodiment of the present invention, shown by enlarging area A of FIG. 2. Here, the plurality of injection holes 71b are arranged to be inclined upward from the gas supply ring 75b toward the lower surface 52 of the gate valve 50 based on the horizontal direction. Specifically, the upward tilt angle, that is, the upward angle (θ), can be calculated through Equation 2 described above. Referring to FIG. 4, the upward angle θ is calculated on the assumption that the position where the purge gas is reflected and returned from the lower surface of the gate valve 50 after being injected at an angle is located in the center of the first flow path 31. It is a value. In practice, this upward angle (θ) is preferably within the range of 30° to 45°. If the upward angle θ is less than the lower limit, compensation for the central deflection of the purge gas is insufficient, and if it is greater than the upper limit, the purge gas is injected in an excessive vertical direction, thereby causing the curtain at the center of the lower surface 52 of the gate valve 50. The effect is weakened. That is, the gas supply device 100 according to the embodiment can ensure that the upward angle θ satisfies the above-mentioned range. In addition, the diameter (d) of the first flow path 31 and the position (k) of the injection hole 71 can be set through the upward angle (θ) and the above-described Equation 2, thereby achieving the above-described effect. It can be derived.

Meanwhile, FIG. 5 is a longitudinal cross-sectional view of a purge gas injection structure 70c according to another embodiment of the present invention, shown by enlarging area A of FIG. 2. Referring to FIG. 5, each of the plurality of injection holes 71c spaced apart in the circumferential direction of the gas supply ring 75c includes a plurality of sub-injection holes 71-1, 71-2, and 71 that are further divided in the vertical direction. -3) It can be composed of: In this way, when using a plurality of sub-injection holes, relatively more uniform injection of the purge gas is possible. In order to form these plurality of sub-injection holes (71-1, 71-2, 71-3) spaced apart in the vertical direction, the cross section of the gas supply ring (75c) is not circular as shown in Figure 3a or Figure 4. , It may be an oval shape that is elongated in the vertical direction.

The plurality of sub-injection holes 71-1, 71-2, and 71-3 are inclined upward toward the lower surface 52 of the gate valve 50 based on the horizontal direction from the gas supply ring 75c. It is placed so that Specifically, the upward angles θ ₁ , θ ₂ , and θ ₃ satisfy the range of 30° to 45° upward, similar to the injection hole 71b of FIG. 4 .

However, at this time, since the longitudinal positions of each sub-injection hole (71-1, 71-2, 71-3) are different from each other, the sub-injection holes (71-1, 71-2, 71-) according to these different positions 3) It is necessary to design the upward angle and diameter individually.

First, in terms of the diameters of the sub injection holes (71-1, 71-2, and 71-3), in order to equalize the flow rate in each sub injection hole, the sub injection holes are spaced further apart from the lower surface 52 of the gate valve 50. It is desirable for the injection hole to have a larger diameter.

In addition, in terms of the upward angles (θ ₁ , θ ₂ , θ ₃ ) toward which the sub-injection holes (71-1, 71-2, and 71-3) are directed, in order for each sub-injection hole to satisfy Equation 2, the gate It is preferable that the sub-injection hole spaced further away from the lower surface 52 of the valve 50 has a larger upward angle. This is because in Equation 2, “k” has a larger value the lower the injection hole is.

Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features. You will be able to understand it. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

11: Cleaning gas source
12: Process gas source
13: Purge gas source
16: Diffusion area
17: Buffer space
18: Nozzle hole
21, 22, 23: Supply pipes
31, 32, 33: Euros
40: Shower head unit
41: Inlet port block
43: Diffusion Block
45: spray nozzle
50: gate valve
70, 70a, 70b, 70c: purge gas injection structure
71, 71a, 71b, 71c: injection hole
71-1, 71-2, 71-3: Sub injection hole
75, 75a, 75b, 75c: Gas supply ring

Claims (12)

A cleaning gas source that supplies cleaning gas;
a process gas source supplying process gas;
a first flow path through which the cleaning gas flows;
A gate valve installed in the first flow path to allow or block the cleaning gas by opening and closing the first flow path;
a second flow path flowing the process gas and joining the first flow path downstream of the gate valve;
a shower head unit that sprays the cleaning gas or the process gas that has passed through the gate valve into the chamber; and
It includes a purge gas injection structure that prevents deposition of the process gas on the lower surface of the gate valve by spraying purge gas adjacent to the lower surface of the gate valve,
The purge gas injection structure is,
a gas supply ring formed near the lower surface of the gate valve in a direction surrounding the first flow path;
a third flow path that flows the purge gas into the gas supply ring; and
A gas supply device comprising a plurality of injection holes that communicate with the gas supply ring and spray the purge gas flowing into the gas supply ring adjacent to the lower surface of the gate valve. According to paragraph 1,
The process gas is supplied when the gate valve is closed and injected into the chamber through the shower head unit. According to paragraph 2,
The purge gas is injected to a lower surface of the gate valve when the gate valve is closed. According to paragraph 1,
A gas supply device further comprising a purge gas source that supplies the purge gas to the purge gas injection structure. According to paragraph 1,
A gas supply device wherein the cross-sectional diameter of the gas supply ring is larger than the diameter of the third flow path. According to clause 5,
A gas supply device, wherein the plurality of injection holes are evenly disposed along the circumferential direction of the gas supply ring. According to clause 5,
The plurality of injection holes are arranged along the circumferential direction of the gas supply ring, and are arranged so that the gap between the injection holes on the side farther from the third flow path is tighter than the gap between the third flow path and the injection holes on the closer side. A gas supply device. According to clause 5,
The plurality of injection holes are arranged to be inclined upward from the gas supply ring toward the lower surface of the gate valve based on the horizontal direction. According to clause 8,
A gas supply device wherein the inclined angle satisfies the range of 30° to 45°. According to clause 5,
Each of the plurality of injection holes includes a plurality of sub-injection holes formed to be spaced apart in the vertical direction,
The plurality of sub-injection holes are arranged to be inclined upward from the gas supply ring toward the lower surface of the gate valve based on the horizontal direction. According to clause 10,
A gas supply device in which the diameters of the plurality of sub-injection holes become larger as the plurality of sub-injection holes are positioned lower in the vertical direction. According to clause 10,
The gas supply device in which the angle at which the plurality of sub-injection holes are inclined upward becomes larger as the plurality of sub-injection holes are positioned lower in the vertical direction.