Process cavity shell and cleaning method thereof

Abstract

The invention provides a process cavity shell and a cleaning method thereof. The process cavity shell comprises a shell body, an annular flow channel arranged in the wall part of the shell body and an annular seepage structure communicated with the annular flow channel. And the annular runner is connected with the solvent inlet to convey a cleaning solvent. The annular seepage structure is arranged on the upper portion of the to-be-cleaned wall face, and an outlet of the annular seepage structure is adjacent to the to-be-cleaned wall face. During working, a cleaning solvent slowly and uniformly seeps from the annular seepage structure through the annular flow channel and is tightly attached to a wall surface to be cleaned, and a layer of uniform liquid film flowing downwards is formed under the action of gravity. According to the technical scheme, the flow channel and the seepage structure are arranged on the wall of the shell, a uniform liquid film flowing on the wall is actively formed, full-coverage and dead-corner-free mild washing is conducted on the whole to-be-cleaned wall face, and therefore efficient and thorough online cleaning is achieved, the blind area and the secondary pollution risk of traditional splashing type cleaning are avoided, and the cleaning efficiency is improved. And the process cleanliness and stability of the equipment are improved.

Description

Technical Field

[0001] This application relates to the field of substrate processing equipment technology, specifically to a process cavity housing and its cleaning method. Background Technology

[0002] In semiconductor manufacturing processes, spin coating is a step in uniformly coating a substrate surface with liquid materials such as photoresist. During spin coating, the substrate rotates at high speed, and the liquid material spreads into a film under centrifugal force. To control the process environment and collect excess material, the rotating substrate is typically surrounded by a process chamber, which generally consists of shell components such as inner and outer cups. Under high-speed rotation, excess photoresist at the substrate edges is ejected and sputtered onto the walls of the process chamber.

[0003] If the photoresist sputtered onto the wall surface is not removed in time, it will gradually dry and solidify, forming residues. During subsequent production, these residues may detach and form tiny particles. Once these particles fall onto the surface of the substrate being processed, they will cause defects and affect the yield.

[0004] Currently, there are two main methods for cleaning the walls of process chambers in the industry. One is offline cleaning, which involves disassembling and cleaning components such as process cups during maintenance shutdowns. This method requires interrupting production, reducing the effective utilization rate of the equipment.

[0005] Another method is online cleaning. A common online cleaning method uses a dedicated cleaning tray. Cleaning solvent is dripped into the center of the tray via a supply arm, and then the tray rotates at high speed, using centrifugal force to splash the solvent onto the walls of the process chamber for rinsing. However, this splashing cleaning process is random, and the landing points and distribution of solvent droplets are difficult to cover evenly, often creating cleaning blind spots in some areas. Furthermore, the high-speed splashing of solvent can easily cause secondary splashing upon impact with the walls, and tiny droplets carrying contaminants can cause secondary contamination. The uniformity and thoroughness of existing online cleaning methods still need improvement. Summary of the Invention

[0006] To address the problems of uneven online cleaning, blind spots, and secondary contamination in existing semiconductor process cavities, this application provides a process cavity housing, including a housing with a wall surface to be cleaned. The housing further includes an annular flow channel and an annular exudation structure. The annular flow channel is disposed within the wall of the housing and connected to at least one solvent inlet for conveying cleaning solvent. The annular exudation structure communicates with the annular flow channel and is disposed on the upper part of the wall surface to be cleaned, with its outlet adjacent to the wall surface, for allowing the cleaning solvent to adhere to the wall surface and flow out, thereby forming a downward-flowing liquid film on the wall surface.

[0007] Preferably, an annular buffer groove is further provided between the annular flow channel and the annular exudation structure. The cross-sectional area of ​​the annular buffer groove is larger than that of the annular flow channel, and is used to equalize the pressure of the cleaning solvent before it flows out of the annular exudation structure.

[0008] Preferably, the annular seepage structure is an annular slit continuously arranged circumferentially along the wall surface to be cleaned.

[0009] Preferably, the width of the annular slit is 0.05 mm to 0.5 mm.

[0010] Preferably, the annular exudation structure includes a plurality of micropores evenly arranged circumferentially along the wall surface to be cleaned.

[0011] Preferably, the pore size of the plurality of micropores is 0.05 mm to 0.5 mm.

[0012] Preferably, the outlet of the annular exudation structure has a preset circumferential tilt angle so that the cleaning solvent forms a liquid film with a circumferential flow component on the wall surface to be cleaned.

[0013] Preferably, the outlet of the annular exudation structure has an inclined angle facing downwards towards the wall surface to be cleaned, so as to actively guide the cleaning solvent to adhere to the wall surface to be cleaned and flow.

[0014] Preferably, the outlet of the annular effluent structure is tangentially positioned along the current location of the wall surface to be cleaned.

[0015] Preferably, the housing has a double-walled structure, consisting of a housing body and a cover plate, and the annular flow channel is formed by an open groove machined on the housing body and the cover plate together forming a closed structure.

[0016] Preferably, the annular exudation structure is defined by the mating surfaces of the shell body and the cover plate.

[0017] Preferably, the annular seepage structure is an annular slit, which is defined by a step machined on the mating surface of the shell body or the cover plate and the mating surface of another component; a plurality of tiny support columns are provided at circumferential intervals at the bottom of the step to maintain the uniformity of the height of the annular slit after the cover plate and the shell body are fastened.

[0018] Preferably, the annular exudation structure is composed of a series of circumferentially arranged micro-protrusions or micro-grooves machined on the mating surface of the shell body or the cover plate. When the cover plate is pressed against the shell body, the gaps between the micro-protrusions or the micro-grooves form channels for solvent exudation.

[0019] Preferably, the housing is the outer cup of the spin coating equipment, and the wall surface to be cleaned is the inner wall surface of the outer cup.

[0020] Preferably, the housing is the inner cup of the spin coating equipment, and the wall surface to be cleaned is the outer wall surface of the inner cup.

[0021] Preferably, the annular exudation structure is positioned below the projection area of ​​the semiconductor substrate in the spin coating equipment.

[0022] The technical solution of this application provides a substrate processing apparatus, which includes the process cavity housing described in any of the foregoing technical solutions.

[0023] The technical solution of this application provides a cleaning method for the process chamber shell using any of the foregoing technical solutions, comprising the following steps: supplying cleaning solvent to the annular flow channel through the solvent inlet; allowing the cleaning solvent to slowly and uniformly seep out through the annular permeation structure and adhere tightly to the wall surface to be cleaned, forming a uniform liquid film flowing downward under the action of gravity, thereby cleaning the wall surface to be cleaned.

[0024] The technical solution of this application mainly achieves gentle yet thorough cleaning by setting an annular flow channel and an annular exudation structure inside the shell wall to form a continuous and stable flowing liquid film on the wall surface to be cleaned in an active and controlled manner. By forming an adhering liquid film, the entire wall surface to be cleaned is covered without dead angles and gently rinsed, solving the randomness and unevenness problems of traditional splash cleaning and avoiding the risk of secondary pollution. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a substrate processing device according to an embodiment of this application.

[0026] Figure 2 This is a partial cross-sectional view of the process cavity shell when it is applied to the outer cup in an embodiment of this application.

[0027] Figure 3 This is a partial top view of a microporous structure in another embodiment of this application.

[0028] Figure 4 This is a partially enlarged structural diagram of an annular slit formed by the mating surfaces of components in another embodiment of this application.

[0029] In the picture:

[0030] 10: Outer cup; 11: Wall surface to be cleaned; 20: Inner cup; 100: Shell; 101: Shell body; 102: Cover plate; 110: Annular flow channel; 111: Solvent inlet; 120: Annular buffer tank; 130: Annular exudation structure; 131: Annular slit; 132: Micropore; 200: Substrate processing equipment; 400: Solvent supply system; 1311: Support column; 1321: Micro-protrusion. Detailed Implementation

[0031] The present patent type will be described in detail below with reference to the accompanying drawings and specific embodiments. In this specification, the dimensions in the drawings do not represent actual size ratios. The drawings are only used to illustrate the relative positional and connection relationships between the components. Components with the same name or the same reference numerals represent similar or identical structures and are limited to illustrative purposes.

[0032] Figure 1 This is a schematic diagram of a substrate processing apparatus 200 according to an embodiment of this application. This apparatus can be a spin coater, used for wet processes such as photoresist coating on a substrate. In the spin coating process, the wafer rotates at high speed, and excess photoresist is splashed onto the walls of the process chamber. If not cleaned in time, the particles formed after drying will contaminate the wafer, affecting product yield. Existing online cleaning methods, such as those using dummy wafers to splash solvent, suffer from uneven cleaning and cleaning blind spots.

[0033] like Figure 2 As shown, in order to solve the above problems, this application provides a process cavity housing, including a housing 100. In this embodiment, the housing 100 is specifically the outer cup 10 of a spin coating device, which has a wall surface 11 to be cleaned, which is the inner wall surface of the outer cup 10.

[0034] To achieve online cleaning, the structure also includes an annular flow channel 110 and an annular exudation structure 130. The annular flow channel 110 is disposed within the wall of the housing 100 and is used to deliver the cleaning solvent. The annular flow channel 110 is connected to at least one solvent inlet 111, which communicates with an external solvent supply system 400 to receive the cleaning solvent. The annular exudation structure 130 communicates with the annular flow channel 110 and is disposed above the wall surface 11 to be cleaned, with its outlet adjacent to the wall surface 11. When the cleaning solvent flows out from the annular exudation structure 130, it adheres to the wall surface 11 and forms a downward-flowing liquid film due to gravity. This uniform liquid film can cover the entire circumference of the wall surface 11 to be cleaned, dissolving and carrying away any residue adhering to the wall surface.

[0035] To ensure a uniform and stable outflowing liquid film and avoid pressure unevenness caused by localized liquid supply at the solvent inlet 111, an annular buffer tank 120 is provided between the annular flow channel 110 and the annular exudation structure 130. The cross-sectional area of ​​the annular buffer tank 120 is larger than that of the annular flow channel 110. When the cleaning solvent enters the annular buffer tank 120 from the annular flow channel 110, the flow velocity decreases, and the pressure is buffered and homogenized. The annular buffer tank 120 makes the pressure in the entire circumferential direction tend to be uniform, so that the flow rate at each point can be consistent when flowing out from the annular exudation structure 130, which is a prerequisite for forming a uniform liquid film. If the annular buffer tank 120 is not present, after the cleaning solvent enters the annular flow channel 110 from a single solvent inlet 111, there will be pressure loss in the circumferential flow, resulting in high pressure and large flow rate at positions closer to the solvent inlet 111, and low pressure and small flow rate at positions farther away. The annular buffer tank 120 allows the solvent to fully collect and stabilize here, ensuring the consistency of subsequent percolation flow.

[0036] The annular exudation structure 130 can be a continuous annular slit 131 arranged circumferentially along the wall surface 11 to be cleaned. The width of this slit can be controlled between 0.05 mm and 0.5 mm. The narrower slit width design, on the one hand, throttles the fluid and helps to homogenize the flow rate; on the other hand, it allows the solvent to be slowly squeezed out under uniform pressure, and this low-speed outflow method is more conducive to the solvent adhering to the wall.

[0037] As another implementation method, such as Figure 3 As shown, the annular exudation structure 130 may also include a plurality of micropores 132 uniformly arranged circumferentially along the wall surface 11 to be cleaned. The pore diameter can be selected in the range of 0.05 mm to 0.5 mm. The spacing between adjacent micropores 132 is calculated to ensure that the liquid flow from each pore can merge due to surface tension after leaving the outlet, converging into a continuous liquid film. Compared to a continuous annular slit 131, the array of micropores 132 provides another option for structural fabrication.

[0038] To further optimize the flow characteristics of the liquid film, the outlet of the annular exudation structure 130 can have a preset circumferential tilt angle. For the multiple micropores 132, the pore axis of each micropore 132 forms an angle with the radial direction in the top view. This design allows the cleaning solvent to acquire an initial circumferential velocity component during exudation. The liquid film formed on the wall surface 11 to be cleaned no longer flows simply vertically downwards, but exhibits a spiral downward flow path. Compared to purely vertical downward flow, this increases the flow distance and residence time of the solvent on the wall surface, which helps to improve the cleaning effect.

[0039] To ensure reliable solvent adhesion and flow to the wall, the outlet of the annular exudation structure 130 can have an inclined angle pointing downwards towards the wall surface 11 to be cleaned, actively guiding the cleaning solvent to adhere to the wall surface. This design helps the solvent establish contact with the wall surface the moment it leaves the outlet, preventing the solvent from dissipating outwards. Preferably, the outlet of the annular exudation structure 130 is tangentially positioned along the current location of the wall surface to be cleaned, meaning that the initial velocity vector of the outflowing solvent is tangential to the surface of the wall surface 11 to be cleaned, ensuring effective adhesion of the outflow.

[0040] In this embodiment, the housing 100 preferably adopts a double-wall structure. Specifically, this structure is composed of a housing body 101 and a cover plate 102. Figure 2 As shown, the annular flow channel 110 is formed by an open groove machined on the housing body 101 and the cover plate 102 together. Similarly, the annular buffer groove 120 is also formed by machining an open groove with a larger cross-sectional area on the housing body 101 and then closing it with the cover plate 102. This split manufacturing method facilitates the machining and subsequent maintenance of the internal flow channels.

[0041] like Figure 4 As shown, the annular exudation structure 130 can be defined by the mating surfaces of the shell body 101 and the cover plate 102. For example, when the annular exudation structure 130 is an annular slit 131, the slit can be defined by a step machined on the mating surface of the shell body 101 or the cover plate 102 and the mating surface of another component. To ensure the uniformity of the slit height, multiple tiny support columns 1311 can be spaced circumferentially at the bottom of the step. These support columns act as limiters after the components are tightened, preventing the slit from being excessively compressed due to uneven force, thus ensuring the consistency of the entire circumferential outflow.

[0042] Alternatively, the annular exudation structure 130 can be composed of a series of circumferentially arranged micro-protrusions 1321 or micro-grooves machined on the mating surface of the housing body 101 or the cover plate 102. When the cover plate 102 is pressed against the housing body 101, the gaps between the micro-protrusions 1321 or the micro-grooves themselves constitute channels for solvent exudation.

[0043] The above structure can be applied not only to cleaning the outer cup 10 but also to the inner cup 20. In another embodiment, the housing 100 is the inner cup 20 of the spin coating device, and correspondingly, the wall surface 11 to be cleaned is the outer wall surface of the inner cup 20. Its structure is the same in principle as the aforementioned embodiment, both including an annular flow channel 110, an annular buffer groove 120, and an annular exudation structure 130 disposed within the cup wall of the inner cup 20. The difference is that these structures are integrated in the upper part of the inner cup 20, and the outlet of the annular exudation structure 130 faces the outer wall surface of the inner cup 20.

[0044] When applied to the inner cup 20, a preferred design is to position the annular exudation structure 130 below the projected area of ​​the semiconductor substrate in the spin coating equipment, i.e., at the beginning of the area where contaminants tend to accumulate. This arrangement allows the cleaning solvent to be precisely delivered to the wall surface that most needs cleaning, achieving targeted cleaning and saving solvent consumption. Simultaneously, this positioning also prevents splashed photoresist from directly contaminating or clogging the outlet of the annular exudation structure 130 during the spin coating process.

[0045] Corresponding to the aforementioned process chamber shell, its cleaning method can be described based on the aforementioned structure. That is, cleaning solvent is supplied to the annular flow channel 110 through the solvent inlet 111; after the cleaning solvent is pressure homogenized by the annular buffer tank 120, it slowly and evenly seeps out through the annular seepage structure 130 and adheres tightly to the wall surface 11 to be cleaned. Under the action of gravity, it forms a uniform liquid film flowing downward, thereby cleaning the wall surface to be cleaned.

[0046] This method transforms the cleaning process into a smooth and predictable physical process through structural design. The thickness, flow rate, and coverage of the liquid film can be controlled by adjusting the pressure and flow rate of the solvent supply system 400. The smooth flow of the liquid film avoids secondary particulate contamination that may result from high-speed droplet impacts. The combination of the annular buffer tank 120 and the precision exudation structure 130 solves the technical challenge of stably forming a uniform liquid film on vertical walls, making online cleaning of the process chamber walls efficient and reliable.

[0047] The above description is merely a preferred embodiment of this patent type and is not intended to limit the scope of this patent type. Without departing from the design spirit of this patent type, all modifications and improvements made by those skilled in the art to the technical solutions of this patent type should fall within the protection scope defined by the claims of this patent type.

Claims

1. A process chamber housing, comprising a housing having a wall surface to be cleaned, characterized in that, Also includes: An annular flow channel is disposed within the wall of the housing and is connected to at least one solvent inlet for conveying cleaning solvent; as well as An annular permeation structure is connected to the annular flow channel. The annular permeation structure is disposed on the upper part of the wall surface to be cleaned, and its outlet is adjacent to the wall surface to be cleaned. It is used to allow the cleaning solvent to adhere to the wall surface to be cleaned and flow out, so as to form a downward flowing liquid film on the wall surface to be cleaned.

2. The process cavity housing as described in claim 1, characterized in that, An annular buffer groove is also provided between the annular flow channel and the annular exudation structure. The cross-sectional area of ​​the annular buffer groove is larger than that of the annular flow channel, and it is used to equalize the pressure of the cleaning solvent before it flows out of the annular exudation structure.

3. The process cavity housing as described in claim 1 or 2, characterized in that, The annular seepage structure is an annular slit continuously arranged circumferentially along the wall surface to be cleaned.

4. The process cavity housing as described in claim 3, characterized in that, The width of the annular slit is 0.05 mm to 0.5 mm.

5. The process cavity housing as described in claim 1 or 2, characterized in that, The annular exudation structure includes multiple micropores evenly arranged circumferentially along the wall surface to be cleaned.

6. The process cavity housing as described in claim 5, characterized in that, The pore size of the plurality of micropores is from 0.05 mm to 0.5 mm.

7. The process cavity housing as described in claim 1 or 2, characterized in that, The outlet of the annular exudation structure has a preset circumferential tilt angle so that the cleaning solvent forms a liquid film with a circumferential flow component on the wall surface to be cleaned.

8. The process cavity housing as described in claim 1 or 2, characterized in that, The outlet of the annular exudation structure has an inclined angle facing downwards towards the wall surface to be cleaned, so as to actively guide the cleaning solvent to adhere to the wall surface to be cleaned and flow.

9. The process cavity housing as described in claim 8, characterized in that, The outlet of the annular seepage structure is tangentially positioned along the current location of the wall surface to be cleaned.

10. The process cavity housing as described in claim 1, characterized in that, The shell adopts a double-walled structure, consisting of a shell body and a cover plate. The annular flow channel is formed by an open groove machined on the shell body and the cover plate together forming a closed structure.

11. The process cavity housing as described in claim 10, characterized in that, The annular exudation structure is defined by the mating surfaces of the shell body and the cover plate.

12. The process cavity housing as described in claim 11, characterized in that, The annular seepage structure is an annular slit, which is defined by a step machined on the mating surface of the shell body or the cover plate and the mating surface of another component. Preferably, a plurality of tiny support columns are provided at circumferential intervals at the bottom of the step to maintain the uniformity of the height of the annular slit after the cover plate is fastened to the housing body.

13. The process cavity housing as described in claim 11, characterized in that, The annular exudation structure is composed of a series of circumferentially arranged micro-protrusions or micro-grooves machined on the mating surface of the shell body or the cover plate. When the cover plate is pressed against the shell body, the gaps between the micro-protrusions or the micro-grooves form channels for solvent exudation.

14. The process cavity housing as described in any one of claims 1-13, characterized in that, The housing is the outer cup of the spin coating equipment, and the wall surface to be cleaned is the inner wall surface of the outer cup.

15. The process cavity housing as described in any one of claims 1-13, characterized in that, The housing is the inner cup of the spin coating equipment, and the wall surface to be cleaned is the outer wall surface of the inner cup.

16. The process cavity housing as described in claim 15, characterized in that, The annular exudation structure is positioned below the projection area of ​​the semiconductor substrate in the spin coating equipment.

17. A substrate processing apparatus, characterized in that, Includes the process cavity housing as described in any one of claims 1-16.

18. A cleaning method using a process chamber housing as described in any one of claims 1-16, characterized in that, Includes the following steps: Cleaning solvent is supplied to the annular flow channel through the solvent inlet; The cleaning solvent slowly and evenly seeps out through the annular exudation structure and adheres tightly to the wall surface to be cleaned. Under the action of gravity, it forms a uniform liquid film that flows downward, thereby cleaning the wall surface.

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