Backflow prevention device and substrate processing apparatus
The backflow prevention device with a protective cover and gas exhaust unit addresses the issue of volatile gas backflow, ensuring cleaner process environments and improved substrate yield in semiconductor manufacturing.
Patent Information
- Application Number
- JP2025538421
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-30
- Filing Date
- 2023-12-13
- Publication Date
- 2026-01-08
AI Technical Summary
Volatile gases from a cup backflow into the process chamber, causing substrate surface corrosion and yield reduction during substrate cleaning processes in semiconductor manufacturing.
A backflow prevention device with a protective cover and gas exhaust unit is integrated into the substrate processing apparatus, featuring a liquid receiving port and a gas exhaust port to prevent volatile gases from entering the process chamber.
Effectively prevents volatile gases from backflowing into the process chamber, thereby reducing substrate surface corrosion and maintaining substrate quality.
Smart Images
Figure 2026500769000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to the field of semiconductor manufacturing, and more particularly to a backflow prevention device and a substrate processing apparatus. [Background technology]
[0002] During operation of the cleaning device, a nozzle in a process chamber supplies chemical liquid to the surface of a rotating substrate. The purpose of cleaning the substrate is achieved by using chemical liquids of different concentrations and amounts on the substrate to etch and clean particles adhering to the surface of the substrate and ensure the cleanliness of the substrate. Typically, the nozzle is pre-cleaned above a cup before supplying chemical liquid to the substrate. The chemical liquid at the nozzle's liquid outlet drips into the cup, keeping the chemical liquid supplied from the nozzle to the substrate fresh and clean. If the cleaning device is not in operation for a long period of time, the nozzle is automatically cleaned above the cup, and the chemical liquid at the nozzle's liquid outlet drips into the cup at regular intervals, keeping the chemical liquid in the nozzle fresh and clean.
[0003] The cup has a cup body shape with a completely open top. The chemical solution in the nozzle is, for example, a highly concentrated acid or alkaline solution. Due to the inherent volatility of highly concentrated acids and alkaline solutions, large amounts of volatile gases, such as acid mist and acid gas, from the chemical solution evaporate through the fully open opening of the cup into the process chamber of the cleaning equipment, contaminating the process environment inside the chamber. When the substrate is rotated and the chemical solution is spin-dried, the acid gas adheres to the first exposed part. To prevent toxic gases from entering the process chamber and causing harm to humans, the toxic gases are typically sucked out by the cleaning equipment's box exhaust system, creating a negative pressure atmosphere inside the process chamber. If the chemical solution needs to be recovered, the liquid discharge line of the cup is connected to a chemical distribution system (CDS), and the chemical solution in the cup, such as N-methylpyrrolidone (NMP), is collected in the CDS for recovery. As a result, volatile gases such as NMP that accumulate in the cup's chemical discharge line tend to flow back through the cup into the negative pressure process chamber, causing the NMP gas to adhere to the substrate surface, especially the center of the substrate. Because the area and degree of volatile gas that adheres to the substrate surface differ depending on the type of chemical, harmful corrosion occurs, significantly reducing the substrate yield in the actual cleaning process. Summary of the Invention
[0004] The present invention aims to solve the problem in the prior art that a large amount of volatile gas in a cup backflows into a process chamber and corrodes the surface of a substrate. Therefore, the present invention provides a backflow prevention device and a substrate processing apparatus that can exhaust gas in the backflow prevention device from a process chamber and prevent the gas from backflowing into the process chamber.
[0005] In order to solve the above problem, one embodiment of the present invention provides a backflow prevention device. The backflow prevention device of the present invention comprises: a cup having an opening at its top; a protective cover that covers the opening of the cup and has a liquid receiving port and a gas exhaust port, the liquid receiving port being used as a nozzle that drips the chemical liquid into the cup; a gas exhaust unit connected to the inside of the cup through the gas exhaust port of the protective cover and configured to suck in volatile gases within the cup.
[0006] Another embodiment of the present invention provides a substrate processing apparatus. The substrate processing apparatus according to the present invention includes a process chamber, a substrate chuck disposed within the process chamber for carrying a substrate; the nozzle for supplying a chemical solution to the substrate; and the backflow prevention device described above, wherein the backflow prevention device and the nozzle are both disposed within the process chamber.
[0007] Compared with the prior art, the present invention has the following beneficial effects:
[0008] In the backflow prevention device of the present invention, a protective cover is provided on the cup, and the protective cover is provided with a liquid receiving port and a gas exhaust port. A chemical liquid is dripped into the cup from the liquid receiving port using a nozzle, and gas in the cup is exhausted through the gas exhaust part and the gas exhaust port of the protective cover, thereby effectively preventing the gas in the cup from flowing back into the process environment around the cup.
[0009] The substrate processing apparatus of the present invention employs the backflow prevention device described above, so that the gas in the cup is exhausted from the process chamber by the gas exhaust unit through the gas exhaust port of the protective cover, preventing the volatile gas in the cup from flowing back into the process chamber and thus preventing the backflow gas from corroding the substrate surface in the process chamber.
[0010] Other features and corresponding advantages of the present invention are described in the specification below, and it will be understood that at least some of the beneficial effects will be apparent from the description of the invention. [Brief explanation of the drawings]
[0011] FIG. 1 is a schematic perspective view illustrating the operating principle of a substrate processing apparatus according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the backflow prevention device according to the first embodiment of the present invention. FIG. 3 is a perspective schematic view of the backflow prevention device according to the first embodiment of the present invention. FIG. 4 is a perspective schematic view of a backflow prevention device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0012] Hereinafter, embodiments of the present invention will be described using specific examples. Other advantages and effects of the present invention will be readily apparent to those skilled in the art from the description herein. Although the present invention will be described in conjunction with a preferred embodiment, this does not mean that the features of the present invention are limited to this embodiment. On the contrary, the purpose of the description in connection with the embodiment is to encompass other alternatives or modifications that may be expanded based on the scope of the present invention. In order to provide a thorough understanding of the present invention, the following description includes many specific details. The present invention can also be practiced without these details. Furthermore, some specific details will be omitted to avoid confusion or obscuring the focus of the present invention. It should be noted that the embodiments and features of the embodiments of the present invention can be combined with each other unless they are inconsistent.
[0013] In this specification, like reference numerals and characters refer to like elements in the following drawings. Therefore, it should be noted that once an item is defined in one drawing, it is not necessary to further define and explain that item in the following drawings.
[0014] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings, and it is clear that the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without any creative efforts fall within the protection scope of the present invention.
[0015] In describing the present invention, it should be noted that the orientations or positional relationships indicated by terms such as "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," and "outside" are based on the orientations or positional relationships shown in the accompanying drawings. This is merely for the convenience and simplification of the description of the present invention and does not indicate or suggest that the referenced devices or elements must have a particular orientation, be configured, or operate in a particular orientation. Therefore, it should not be understood as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes and should not be construed as indicating or implying relative importance.
[0016] In the description of the present invention, unless otherwise expressly specified and defined, the terms "attached," "connected," and "communicating" should be understood broadly, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, and the connection may be a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, or an internal communication between two elements. The specific meanings of the above terms in the present invention will be understood by those skilled in the art.
[0017] To clarify the objectives, technical solutions and advantages of the present invention, the following describes in more detail the embodiments of the present invention with reference to the accompanying drawings.
[0018] 1, a substrate processing apparatus 1 according to the present invention includes a process chamber 10, a substrate chuck 120, a nozzle 130, and a backflow prevention device. A reaction chamber 110 is provided inside the process chamber 10, and the reaction chamber 110 has a cup shape and an open top. A substrate chuck 120 is provided inside the reaction chamber 110 and is used to transport a substrate w. In other alternative embodiments, the reaction chamber 110 may also have a square shape or other structures, and the shape of the reaction chamber 110 is not limited in this application.
[0019] Both the nozzle 130 and the backflow prevention device are provided inside the process chamber 10 and are both located outside the reaction chamber 110. When the nozzle 130 is operating, the chemical liquid is supplied to the substrate w from the upper opening of the reaction chamber 110. When the nozzle 130 is not operating, that is, when the nozzle 130 has finished supplying the chemical liquid to the substrate w, the nozzle 130 moves to the position of the backflow prevention device and performs cleaning, such as pre-cleaning or automatic cleaning, to keep the chemical liquid inside the nozzle 130 always clean.
[0020] The chemical liquid sprayed onto the substrate w by the nozzle 130 is, for example, an acid chemical liquid, an alkaline chemical liquid, an organic chemical liquid, a rinse liquid, etc. The acid chemical liquid is, for example, DHF (dilute hydrofluoric acid), the alkaline chemical liquid is, for example, SC1 (a mixture of ammonia water, hydrogen peroxide water, and water), the organic chemical liquid is, for example, IPA (isopropanol), and the rinse liquid is, for example, DIW (deionized water).
[0021] As shown in FIGS. 1 to 3, the backflow prevention device according to the present invention comprises a cup 141, a protective cover 142, and a gas exhaust unit. The cup 141 has an opening 1411, and the protective cover 142 covers the opening 1411 of the cup 141 and is provided with a liquid receiving port 1421 and a gas exhaust port 1422. When the nozzle 130 is not operating, the chemical liquid drips from the liquid receiving port 1421 into the cup 141. The gas exhaust unit comprises a negative pressure pipe 143 and a gas exhaust device 300. A first end of the negative pressure pipe 143 communicates with the interior of the cup 141 via the gas exhaust port 1422 of the protective cover 142. A second end of the negative pressure pipe 143 is connected to the gas exhaust device 300. The gas exhaust device 300 continuously sucks in the volatile gas in the cup 141 through the negative pressure line 143 regardless of whether the nozzle 130 has been cleaned or not, and the volatile gas of the chemical liquid in the cup 141, such as acid mist or acid gas, is continuously discharged from the process chamber 10.
[0022] In this embodiment, the gas exhaust device 300 may be a collection box exhaust system that has been conventionally used in substrate processing apparatuses 1. Collection box exhaust systems are typically used to suck gases from within the process chamber 10. In this embodiment, the gas exhaust device 300 and the cup 141 are connected via a negative pressure line 143, and the cup 141 and the process chamber 10 share a single gas exhaust device 300. The gas exhaust device 300 not only sucks gases from within the process chamber 10 but also continuously sucks volatile gases from within the cup 141 via the negative pressure line 143. At the same time, it effectively prevents volatile gases from within the cup 141 from backflowing into the process chamber 10 without affecting the cleaning of the nozzle 130. This prevents backflow gases from contaminating the process environment within the process chamber 10 and causing undesirable corrosion on the surface of the substrate w. Here, the negative pressure pipe 143 may be made of a PFA (polyfluoroalkoxy) material, and may be fixed to the process chamber 10 via a fixing plate 1431. The negative pressure pipe 143 may be provided with an adjusting valve 1431 for adjusting the flow rate of gas in the negative pressure pipe 143. The adjusting valve 1431 is, for example, a needle valve (NV).
[0023] As shown in FIG. 3 , the protective cover 142 of the backflow prevention device covers the top of the cup 141, and the liquid receiving port 1421 and the gas exhaust port 1422 are both provided on the upper wall of the protective cover 142. In this embodiment, the protective cover 142 corresponds to the top lid of the cup 141 and covers half of the top of the cup 141. The protective cover 142 is temporarily aligned with the cup 141, thereby ensuring the basic positioning of the protective cover 142. The side walls of the protective cover 142 are fixed to the side walls of the cup 141 by fasteners 1423. Here, the fasteners 1423 consist of three anti-rust bolts, which are evenly spaced along the outer periphery of the protective cover 142 and secure the protective cover 142 and cup 141 at an angle of 120°.
[0024] 1 and 3, the liquid receiving port 1421 protrudes from the upper wall of the protective cover 142 and extends outward, and the upper surface of the liquid receiving port 1421 is not higher than the liquid outlet surface 1301 of the nozzle 130, which prevents the nozzle 130 from interfering with the liquid receiving port 1421 and colliding with each other when rotating between the cup 141 and the substrate w. Furthermore, if the liquid receiving port 1421 and the liquid outlet of the nozzle 130 do not interfere with each other, it is desirable to position the liquid receiving port 1421 as close as possible to the liquid outlet of the nozzle 130 so that the chemical liquid does not splash from the liquid receiving port 1421 when the nozzle 130 drips the chemical liquid into the cup 141.
[0025] 2, the area of liquid receiving port 1421 of protective cover 142 is set to be no more than one-third the area of opening 1411 of cup 141, preventing the liquid receiving port 1421 from becoming too large and causing acid mist or acid gas to overflow. Furthermore, it is preferable that the size of liquid receiving port 1421 is not too small, and that the size of liquid receiving port 1421 is at least larger than the size of the liquid outlet of nozzle 130. This allows nozzle 130 to smoothly perform cleaning of cup 141, such as preliminary cleaning or automatic cleaning.
[0026] 1 and 3, the backflow prevention device further includes a liquid discharge pipe 400, which is provided below the cup 141. Normally, when there is no need to recover the chemical liquid in the cup 141, the liquid discharge pipe 400 is connected to a manufacturing control system, and the chemical liquid in the cup 141 is directly discharged to the manufacturing control system. When there is a need to recover the chemical liquid in the cup 141, the liquid discharge pipe 400 is connected to the recovery processing device 200, and the chemical liquid in the cup 141 passes through the recovery processing device 200, which supplies the treated chemical liquid to the nozzle 130. The chemical liquid supply pipe between the nozzle 130 and the recovery processing device 200 is composed of a manual valve (MV) 510, a pressure control valve (PCV) 520, and a needle valve (NV) 530. A manual valve 510 is used to control the on / off of the chemical supply line, a pressure control valve 520 is used to control the pressure in the supply line, and a needle valve 530 is used to control the flow rate of the chemical in the supply line.
[0027] In this embodiment, the recovery processing device 200 may employ a chemical distribution system (CDS) present in the substrate processing device 1. The chemical distribution system has a gas exhaust port connected to a gas exhaust port of a factory service system to exhaust gases within the chemical distribution system. The liquid discharge line 400 is provided with a control valve 410, which may be an air pressure valve. When the nozzle 130 is being cleaned, i.e., while the nozzle 130 is dripping the chemical liquid from the liquid receiving port 1421 into the cup 141, the air valve is opened, and the chemical liquid in the cup 141 is introduced into the chemical distribution system through the liquid discharge line 400. The chemical liquid in the nozzle 130 is, for example, N-methylpyrrolidone (NMP). After the cleaning of the nozzle 130 is completed, i.e., after the nozzle 130 has finished dripping the chemical liquid into the cup 141, the nozzle 130 moves above the substrate w and supplies the chemical liquid to the substrate w. At this time, the air pressure valve is closed to prevent gas from the chemical liquid distribution system from flowing back into the process chamber 10 via the liquid discharge pipe 400 and the cup 141. Since the gas exhaust device 300 continuously suctions the inside of the cup 141 via the negative pressure pipe 143, when the air valve changes from closed to open, the volatile gas accumulated in the liquid discharge pipe 400 enters the cup 141 and is then sucked into the cup 141. This effectively prevents the volatile gas accumulated in the liquid discharge pipe 400 from flowing back into the process chamber 10 through the inside of the cup 141, and prevents the surface of the substrate w from being adhered to or corroded by the volatile gas.
[0028] Second embodiment Referring to FIG. 4, the second embodiment provides another backflow prevention device different from the first embodiment.
[0029] Furthermore, the protective cover 142A of the backflow prevention device may cover the outer periphery of the cup 141A, forming a cavity between the protective cover 142A and the outer periphery of the cup 141A. The liquid receiving port 1421A is provided on the upper wall of the protective cover 142A, and the gas exhaust port 1422A is provided on the side wall of the protective cover 142A. In this embodiment, the protective cover 142A completely covers the outer periphery of the cup 141A in correspondence with the sealing cover of the cup 141A and is fixed to the outer periphery of the cup 141A. The protective cover 142A and the cup 141A may be integrally formed by welding. In another embodiment, the protective cover 142A may be half-covered by the outer periphery of the cup 141A, i.e., it may cover the opening and part of the side wall of the cup 141A. A cavity is formed between the protective cover 142A and the opening and part of the side wall of the cup 141A. Alternatively, the protective cover 142A may be provided in the form of a sleeve on the outside of the cup 141A and fixed to the inside of the process chamber by a supporter (not shown). Note that a seal may be provided at the position where the protective cover 142A comes into contact with the outside of the cup 141A to prevent gas in the cavity between the protective cover 142A and the cup 141A from entering the inside of the process chamber.
[0030] Specifically, when a cavity is formed between the protective cover 142A and the outer peripheral surface of the cup 141A, a buffer distance is provided between the liquid receiving opening 1421A of the protective cover 142A and the upper edge 1401A of the cup 141A, which provides a buffer space for the volatile gas in the cup 141A to prevent the volatile gas in the cup 141A from directly flowing back into the process chamber through the liquid receiving opening 1421A.
[0031] Along the height direction H of the cup 141A, the position of the gas exhaust port 1422A of the protective cover 142A is not lower than the position along the upper edge 1401A of the cup 141A, and is used to timely exhaust gas in the cavity between the protective cover 142A and the cup 141A, particularly gas between the upper wall of the protective cover 142A and the upper edge 1401A of the cup 141A.
[0032] Finally, it should be noted that the above embodiments are only used to explain the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, and some or all of the technical features may be replaced with means having equivalent functions. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of each embodiment of the present invention.
Claims
1. a cup having an opening at the top; a protective cover that covers the opening of the cup and has a liquid receiving port and a gas exhaust port, the liquid receiving port being used as a nozzle that drips the chemical liquid into the cup; a gas exhaust section connected to the inside of the cup through the gas exhaust port of the protective cover, and configured to suck in volatile gases within the cup.
2. 2. The backflow prevention device according to claim 1, wherein the protective cover covers the top of the cup, and the liquid receiving port and the gas exhaust port are both located on the upper wall of the protective cover.
3. 3. The backflow prevention device according to claim 2, wherein the liquid receiving port protrudes from an upper wall of the protective cover and extends outward.
4. 3. The backflow prevention device of claim 2, wherein the sidewall of the protective cover is secured to the sidewall of the cup by fasteners.
5. 2. The backflow prevention device according to claim 1, wherein the protective cover covers the outer periphery of the cup, forming a cavity between the protective cover and the outer periphery of the cup, the liquid receiving port is provided in the upper wall of the protective cover, and the gas exhaust port is provided in the side wall of the protective cover.
6. 6. The backflow prevention device according to claim 5, wherein the protective cover is integrally formed with the cup.
7. 6. The backflow prevention device according to claim 5, wherein the gas exhaust port of the protective cover is not located below the upper edge of the cup along the height direction of the cup.
8. 8. The backflow prevention device according to claim 1, wherein the area of the liquid receiving opening does not exceed one-third of the area of the opening of the cup.
9. a liquid discharge pipe disposed under the cup and configured to discharge the medicinal liquid from the inside of the cup; a control valve disposed on the liquid discharge line for opening and closing the liquid discharge line; 2. The backflow prevention device of claim 1, wherein the control valve is open while the nozzle is dripping the chemical liquid from the liquid receiving port into the cup, and the control valve is closed when the nozzle has finished dripping the chemical liquid into the cup.
10. The backflow prevention device of claim 9, further comprising: a recovery processing unit; and the liquid discharge pipeline and the nozzle, each connected to the recovery processing unit, wherein the chemical liquid in the cup is discharged to the recovery processing unit via the liquid discharge pipeline, and the recovery processing unit supplies the treated chemical liquid to the nozzle.
11. 2. The backflow prevention device according to claim 1, wherein the gas exhaust section includes a negative pressure pipe and a gas exhaust device, and the gas exhaust device continuously sucks the volatile gas in the cup through the negative pressure pipe.
12. 12. The backflow prevention device according to claim 11, wherein the negative pressure line is provided with an adjustment valve for adjusting the flow rate of gas in the negative pressure line.
13. A substrate processing apparatus, a process chamber; a substrate chuck disposed within the process chamber for carrying a substrate; the nozzle for supplying a chemical solution to the substrate; The backflow prevention device according to any one of claims 1 to 12, The substrate processing apparatus, wherein the backflow prevention device and the nozzle are both disposed within the process chamber.