Plasma cleaning device

Abstract

The present invention is a plasma cleaning device, which includes a cavity, a radio frequency electrode, a stage, an electrode, a gas dispersion ring and a partition ring. The gas dispersion ring is connected to the cavity through a fastening member, and the partition ring is lower than the gas dispersion ring. A partition space is defined between the partition ring and the cavity, and the fastening member is located in the partition space. The partition ring also defines a reaction space with the stage, and the fastening member is restricted outside the reaction space. During the cleaning process of the plasma cleaning device, argon ions impact the aluminum substrate on the stage, and the partition ring can shield the fastening member to prevent some of the sputtered aluminum from adsorbing on the fastening member.

Description

Technical Field

[0001] The present invention relates to a plasma cleaning device, and more particularly to a plasma cleaning device that shields fasteners through a separation ring to reduce dirt adsorption on the fasteners. Background Art

[0002] In the plasma cleaning process of semiconductors, a plasma cleaning device generates plasma, and a gas dispersion ring provides argon gas, which is dissociated and then impacts the wafer to knock out dirt on the wafer surface, achieving the effect of wafer cleaning. However, some dirt is suspended in the cavity and may fall back onto the wafer surface and follow the wafer through subsequent processes, such as a metal coating process. If the dirt falls on the future wiring area of the wafer, the wires cannot conduct, thereby reducing the product yield.

[0003] One method to improve the above problem is to replace the wafer with an aluminum substrate to be impacted by argon ions at fixed intervals. The sputtered aluminum can react with the dirt remaining in the cavity and adhere to the baffle of the cavity, reducing the probability of dirt falling back onto the wafer surface.

[0004] However, the gas dispersion ring is usually fixed to the cavity using fasteners (e.g., screws). The screws grounded through the cavity are prone to adsorb metal ions (aluminum ions), causing dirt to adhere to the screw surface, and the dirt may peel off and fall onto the wafer. Since the screws are usually made of stainless steel and effective surface treatment cannot be performed on them, it is difficult to solve the problem of dirt generation. Summary of the Invention

[0005] Therefore, in order to overcome the deficiencies of the prior art, embodiments of the present invention provide a plasma cleaning device that can reduce the probability of dirt adhering to fasteners (e.g., screws) and prevent the dirt from peeling off and falling onto the wafer surface. Thus, the cleanliness of the wafer can be increased.

[0006] Based on at least one of the foregoing purposes, the plasma cleaning device provided by embodiments of the present invention includes a cavity, a radio frequency electrode, a stage, an electrode, a gas dispersion ring, and a separation ring. The cavity has an accommodation space and a cavity top, and the radio frequency electrode is connected to the cavity top. The stage is located in the accommodation space and is used to carry at least one substrate, and the electrode is connected to the stage. The gas dispersion ring is connected to the cavity through at least one fastener, and the gas dispersion ring has a plurality of pores for process gas to enter the accommodation space. The separation ring is connected to the gas dispersion ring, and the separation ring and the stage define a reaction space, and the separation ring is located between the fastener and the reaction space to limit the fastener outside the reaction space, where the pores of the gas dispersion ring are located in the reaction space.

[0007] Based on at least one of the foregoing purposes, the plasma cleaning device provided by an embodiment of the present invention includes a cavity, a radio frequency electrode, a stage, an electrode, a gas dispersion ring, and a separation ring. The cavity has an accommodation space and a cavity top, and the radio frequency electrode is connected to the cavity top. The gas dispersion ring is connected to the cavity through at least one locking member, and the gas dispersion ring has a plurality of air holes for introducing a process gas into the accommodation space. The separation ring is lower than the gas dispersion ring, and a separation space is defined between the separation ring and the cavity. The locking member is located in the separation space, and the air holes of the gas dispersion ring are restricted outside the separation space.

[0008] Optionally, the separation ring further includes a connecting portion, a side surface, and a bottom surface. The connecting portion is connected to the gas dispersion ring, the side surface is connected to the connecting portion, and the bottom surface is connected to the side surface. The connecting portion and the bottom surface are opposite to each other. The side surface of the separation ring is used to block the dirt falling from the locking member from falling onto the surface of the substrate, and the bottom surface is used to catch the dirt.

[0009] Optionally, a first distance is provided between one end of the bottom surface of the separation ring and the side wall of the cavity, and a second distance is provided between the locking member and the side wall of the cavity, where the first distance is less than the second distance.

[0010] Optionally, the surface of the gas dispersion ring further includes a plurality of convex portions adjacent to the reaction space for attaching dirt on the cavity.

[0011] Optionally, the surface of the gas dispersion ring is subjected to roughening treatment and non-conductive treatment to form an uneven surface for attaching dirt on the cavity.

[0012] Optionally, the roughening treatment is chemical roughening treatment, mechanical roughening treatment, or organic solvent roughening treatment. The non-conductive treatment is anodic treatment.

[0013] Optionally, the surface roughness (Ra) of the surface of the gas dispersion ring is 8 to 12 micrometers (μm).

[0014] Optionally, the plasma cleaning device further includes a vacuum pumping system connected to the accommodation space of the cavity for pumping out the fluid in the accommodation space.

[0015] Optionally, the plasma cleaning device further includes a first shield plate located in the accommodation space and adjacent to the cavity top, and the first shield plate has a plurality of first openings to form an uneven bottom surface.

[0016] In short, the plasma cleaning device provided by an embodiment of the present invention uses a separation ring to shield the locking member between the gas dispersion ring and the cavity, so as to reduce the probability of dirt attaching to the locking member. Furthermore, the separation ring can also catch the dirt falling from the locking member. In this way, the cleanliness of the wafer can be increased, so it has an advantage in the market (such as semiconductor) that has a demand for plasma cleaning devices and processes. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the plasma cleaning device according to an embodiment of the present invention.

[0018] Figure 2 It is a partial schematic diagram of the plasma cleaning device according to an embodiment of the present invention.

[0019] Figure 3 It is a partial schematic diagram of the plasma cleaning device according to another embodiment of the present invention.

[0020] Figure 4 It is a partial schematic diagram of the plasma cleaning device according to still another embodiment of the present invention.

[0021] Figure 5 It is a partial schematic diagram of the plasma cleaning device according to yet another embodiment of the present invention.

[0022] Figure 6 It is a partial schematic diagram of the plasma cleaning device according to yet another embodiment of the present invention.

[0023] Figure 7 It is a partial bottom view schematic diagram of the gas dispersion ring according to yet another embodiment of the present invention.

[0024] Explanation of reference numerals: 1 - plasma cleaning device; 11 - cavity; 111 - top of the cavity; 113 - vacuum pumping system; 13 - stage; 131 - cooling pipeline; 15 - gas dispersion ring; 151 - locking member; 153 - convex portion; 155 - air hole; 17, 27, 37 - partition ring; 171, 271, 371 - connecting portion; 173, 273, 373 - side surface; 175, 275, 375 - bottom; 177 - partition ring locking member; 19 - first shield; 191 - first opening; 193 - first closed portion; 195 - groove; d1 - first distance; d2 - second distance; E1 - radio frequency electrode; E2 - electrode; L1 - vertically extending line; L2, L3 - horizontally extending lines; S - accommodation space; S1 - reaction space; S2 - partition space; W - substrate. Detailed Description of the Embodiment

[0025] To fully understand the purpose, features and effects of the present invention, the following specific embodiments are hereby provided in conjunction with the accompanying drawings to make a detailed description of the present invention, as follows.

[0026] First, please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic diagram of the plasma cleaning device according to an embodiment of the present invention, Figure 2It is a partial schematic diagram of the plasma cleaning device according to an embodiment of the present invention. The plasma cleaning device 1 provided by the present invention includes a cavity 11, a radio frequency electrode E1, a stage 13, an electrode E2, a gas dispersion ring 15, a partition ring 17, and a first shutter 19. The cavity 11 has a cavity top 111 and an accommodation space S, and the material of the cavity top 111 is, for example but not limited to, ceramic.

[0027] An accommodation space S of the cavity 11 is provided with a stage 13, and the stage 13 is used to carry at least one substrate W. The plasma cleaning device 1 may further be provided with a cooling pipeline 131, and the cooling pipeline 131 is connected to the stage 13 (for example, arranged inside the stage 13) to adjust the temperature of the substrate W.

[0028] In the pre-clean process of semiconductors, the substrate W is a wafer. The dirt on the wafer can be bombarded by plasma in the pre-clean process, and the dirt and by-products (such as aluminum oxide, silicon dioxide, silicon nitride, carbon, organic compounds, polluting gases, etc.) adhere to or suspend in the cavity 11. When cleaning the plasma cleaning device 1, a metal substrate (such as an aluminum substrate) is used as the substrate W, and aluminum can be sputtered out by the plasma, and react with the dirt and by-products or make the dirt and by-products adhere to the sputtered aluminum.

[0029] Specifically, the stage 13 is connected to the electrode E2, and the electrode E2 is located above the stage 13, so that the stage 13 carries the substrate W through the electrode E2. The cavity top 111 is connected to the radio frequency electrode E1, and the radio frequency electrode E1 and the electrode E2 can generate a potential difference in the accommodation space S of the cavity 11.

[0030] The gas dispersion ring 15 is connected to the cavity 11, so that a process gas (such as argon) enters the accommodation space S of the cavity 11 through a plurality of air holes 155 of the gas dispersion ring 15.

[0031] When cleaning the plasma cleaning device 1, the radio frequency electrode E1 and the electrode E2 generate a potential difference in the cavity 11 and make the electrons have energy. When the electrons strike the argon introduced into the cavity 11, the argon can be dissociated into argon ions, and a high-density plasma is generated in the cavity 11. After the plasma in the cavity 11 is accelerated, the argon ions strike the aluminum substrate and the aluminum is sputtered out, so as to react with the dirt and by-products or make the dirt and by-products adhere to the sputtered aluminum, and can be captured by the first shutter 19.

[0032] The first shutter 19 is located within the accommodation space S and adjacent to the top 111 of the cavity. The first shutter 19 has a plurality of first openings 191 to form an uneven bottom surface, and the dirt adhering to the aluminum can be captured by the uneven bottom surface of the first shutter 19, so as to reduce the probability of suspension within the accommodation space S of the cavity 11. Specifically, the first shutter 19 has a plurality of first openings 191 and a plurality of first closed portions 193, and the first closed portions 193 are adjacent to the top 111 of the cavity and opposite to the first openings 191, so as to form a plurality of grooves 195 in the first shutter 19. The first openings 151 of the grooves 195 face the direction of the substrate W to accommodate the aluminum sputtered out and carrying dirt.

[0033] Since the first shutter 19 has an uneven bottom surface, its surface area is larger than that of a flat bottom surface, that is, the surface area for adsorbing dirt is larger. Therefore, the frequency of replacing the first shutter 19 can be reduced. Thus, the cleaning cycle of the plasma cleaning device 1 can be extended. The material of the first shutter 19 can be quartz, ceramic, silicon carbide or alumina, but the present invention is not limited thereto.

[0034] The uneven bottom surface or the grooves 195 of the first shutter 19 can be coated with a chemical material, and the chemical material can be yttrium oxide, alumina or ceramic. The purpose of coating the chemical material on the uneven bottom surface or the grooves 195 is to create an uneven surface (for example, a concave-convex surface) to increase the surface area of the uneven bottom surface or the grooves 195. Thus, it is easier to capture or hold the aluminum carrying dirt.

[0035] The gas dispersion ring 15 is connected to the cavity 11 through at least one locking member 151, and the locking member 151 is, for example but not limited to, a screw. In one embodiment, the gas dispersion ring 15 is locked to the top 111 of the cavity through the locking member 151. In other embodiments, the gas dispersion ring 15 is locked to the side wall of the cavity 11 through the locking member 151.

[0036] The partition ring 17 is connected to the gas dispersion ring 15 and the partition ring 17 is locked to the cavity 11 through the partition ring locking member 177. Specifically, the partition ring 17 is an annular body and is lower than the gas dispersion ring 15. Taking the vertical extension line L1 of the minimum diameter of the partition ring 17 as the boundary and the horizontal extension line L2 of the top of the stage 13 as the boundary, the partition ring 17 and the stage 13 define a reaction space S1. Furthermore, taking the horizontal extension line L3 of the bottom 175 of the partition ring 17 as the boundary and the side wall of the cavity 11 as the boundary, the partition ring 17 and the cavity 11 surround a partition space S2.

[0037] The top surfaces of the partition ring 17 and the locking member 151 are on the same side of the gas dispersion ring 15 (for example, Figure 1In [description], the separation ring 17 and the top surface of the locking member 151 are located on the lower side of the gas dispersion ring 15), so as to shield the locking member 151 through the separation ring 17 and reduce the probability of dirt in the reaction space S1 adhering to the locking member 151.

[0038] Specifically, the separation ring 17 is located between the locking member 151 and the reaction space S1 to limit the locking member 151 outside the reaction space S1, and the air holes 155 of the gas dispersion ring 15 are also located in the reaction space S1 to supply process gas to the reaction space S1. That is, the locking member 151 is located in the separation space S2, and the air holes of the gas dispersion ring 15 are restricted outside the separation space S2.

[0039] In one embodiment, the separation ring 17 further includes a connecting portion 171, a side surface 173, and a bottom portion 175. The connecting portion 171 connects to the gas dispersion ring 15, the side surface 173 connects to the connecting portion 171, the bottom portion 175 connects to the side surface 173, and the connecting portion 171 and the bottom portion 175 are opposite to each other. The side surface 173 is perpendicular to the side wall of the cavity 11 and can be used to prevent dirt in the reaction space S1 from adhering to the locking member 151. Furthermore, when a small amount of dirt adheres to the locking member 151, the side surface 173 of the separation ring 17 can also be used to prevent the dirt falling off the locking member 151 from falling onto the surface of the substrate W, and the bottom portion 175 of the separation ring 17 can be used to catch the dirt.

[0040] Please refer to Figure 3 , Figure 3 is a partial schematic view of a plasma cleaning device according to another embodiment of the present invention. As Figure 3 shown, there is a first distance d1 between one end of the bottom portion 175 of the separation ring 17 and the side wall of the cavity 11, and there is a second distance d2 between the locking member 151 and the side wall. The first distance d1 is less than the second distance d2, so that the separation effect of the separation ring 17 on the locking member 151 is better, and it is easier for the separation ring 17 to catch the dirt peeled off from the locking member 151. In other embodiments, the first distance d1 may also be equal to the second distance d2. In other embodiments, the first distance d1 may also be 0, so that the separation space S2 almost forms a closed space.

[0041] In other embodiments, the side surface 173 of the separation ring 17 may not be perpendicular to the side wall of the cavity 11. Please refer to Figure 4 , Figure 4 is a partial schematic view of a plasma cleaning device according to yet another embodiment of the present invention. As Figure 4As shown, the side surface 273 of the separation ring 27 is arc-shaped. Specifically, the separation ring 27 has a connecting portion 271, a side surface 273, and a bottom portion 275, where the connecting portion 271 is connected to the gas dispersion ring 15, the side surface 273 is connected to the connecting portion 271, the bottom portion 275 is connected to the side surface 273, and the connecting portion 271 and the bottom portion 275 are opposite to each other. Similarly, the side surface 273 of the separation ring 27 can be used to prevent dirt in the reaction space S1 from adhering to the locking member 151. When a small amount of dirt adheres to the locking member 151, the side surface 273 of the separation ring 27 can also be used to prevent the dirt falling off the locking member 151 from falling onto the surface of the substrate W, and the bottom portion 275 of the separation ring 27 can be used to hold the dirt.

[0042] In other embodiments, the separation ring 17 may not be connected to the gas dispersion ring 15. Please refer to Figure 5 , Figure 5 which is a partial schematic view of a plasma cleaning device according to another embodiment of the present invention. As Figure 5 shown, the separation ring 37 is connected to the side wall of the cavity 11 through the separation ring locking member 177, and the gas dispersion ring 15 is connected to the top of the cavity 11 of the cavity 11 through the locking member 151. Specifically, the separation ring 37 has a connecting portion 371, a side surface 373, and a bottom portion 375, where the connecting portion 371 is connected to the side wall of the cavity 11, the side surface 373 and the connecting portion 371 are opposite to each other, and the bottom portion 375 is connected to the side surface 373 and the connecting portion 371. Similarly, the side surface 373 of the separation ring 37 can be used to prevent dirt in the reaction space S1 from adhering to the locking member 151. When a small amount of dirt adheres to the locking member 151, the side surface 373 of the separation ring 37 can also be used to prevent the dirt falling off the locking member 151 from falling onto the surface of the substrate W, and the bottom portion 375 of the separation ring 37 can be used to hold the dirt.

[0043] Different from the foregoing embodiments, the separation ring 37 is bounded by the vertical extension line L1 of the side surface 373 and the bottom portion 375, and is bounded by the side wall of the cavity 11, so that the separation ring 37 and the cavity 11 enclose a separation space S2.

[0044] In one embodiment, the gas dispersion ring 15 is directly or indirectly connected to the top of the cavity 11 of the cavity 11 through the locking member 151. In other embodiments, the gas dispersion ring 15 may not be connected to the top of the cavity 11 of the cavity 11. Please refer to Figure 6 , Figure 6 which is a partial schematic view of a plasma cleaning device according to another embodiment of the present invention. As Figure 6 shown, the gas dispersion ring 15 is connected to the side wall of the cavity 11 through the locking member 151.

[0045] Next, please refer to Figure 1 , Figure 2 and Figure 7 , Figure 7It is a partial bottom view schematic diagram of the gas dispersion ring according to another embodiment of the present invention. As Figure 1 、 Figure 2 and Figure 7 shown, the gas dispersion ring 15 is an annular ring body, and the surface of the gas dispersion ring 15 further includes a plurality of convex portions 153, adjacent to the reaction space S1. The plurality of convex portions 153 make the surface of the adjacent reaction space S1 of the gas dispersion ring 15 uneven, so as to enhance the ability to adhere to the dirt in the cavity 11.

[0046] The surface of the gas dispersion ring 15 can also be subjected to roughening treatment and non-conductive treatment to form an uneven surface, so as to further enhance the ability to adhere to the dirt in the cavity 11. Among them, the roughening treatment can be chemical roughening treatment, mechanical roughening treatment or organic solvent roughening treatment, and the non-conductive treatment can be anodic treatment, so that the surface roughness (Ra) of the surface of the gas dispersion ring 15 is 8 to 12 micrometers (μm).

[0047] The plasma cleaning device 1 may further include a vacuum pumping system 113, which is connected to the accommodation space S of the cavity 11 and is used to pump out the fluid in the accommodation space S, where the fluid is, for example but not limited to, the air contained in the cavity 11 before the cleaning process.

[0048] In summary, compared with the prior art, the technical effects of the plasma cleaning device according to the embodiments of the present invention are described as follows.

[0049] In the prior art, in the pre-cleaning process of the wafer, some dirt will adhere to the fasteners between the gas dispersion ring and the cavity, and may fall back onto the wafer surface, or even fall onto the future wiring area of the wafer, which will cause the wires to fail to conduct, thereby reducing the yield of the product. However, since the fasteners are usually stainless steel screws and it is difficult to perform effective surface treatment on them, it is difficult to solve the problem of dirt generation. On the contrary, the plasma cleaning device described in the present invention can shield the fasteners through the partition ring and can further catch the dirt falling from the fasteners to reduce the probability of wafer contamination.

[0050] The above is only a preferred embodiment of the present invention, and is not used to limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made according to the shape, structure, features and spirit described in the scope of the patent application of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A plasma cleaning device, characterized in that, The plasma cleaning device includes: a cavity having an accommodation space and a cavity top; a radio frequency electrode connected to the cavity top; a stage located in the accommodation space and configured to carry at least one substrate; an electrode connected to the stage; a gas dispersion ring connected to the cavity through at least one fastening member, the gas dispersion ring having a plurality of pores for introducing a process gas into the accommodation space, wherein the surface of the gas dispersion ring is subjected to roughening treatment and non-conductive treatment to form an uneven surface for attaching dirt of the cavity; and a partition ring connected to the gas dispersion ring, wherein the partition ring and the stage define a reaction space, and the partition ring is located between the fastening member and the reaction space to confine the fastening member outside the reaction space, wherein the pores of the gas dispersion ring are located in the reaction space; wherein the partition ring further includes a connecting portion, a side surface and a bottom surface, the connecting portion is connected to the gas dispersion ring, the side surface is connected to the connecting portion, the bottom surface is connected to the side surface, and the connecting portion and the bottom surface are opposite to each other, wherein the side surface is configured to block dirt falling from the fastening member from falling onto the surface of the substrate, and the bottom surface is configured to receive the dirt, wherein a first distance is provided between one end of the bottom surface and the side wall of the cavity, and a second distance is provided between the fastening member and the side wall, wherein the first distance is less than the second distance.

2. A plasma cleaning device, characterized in that, The plasma cleaning device includes: a cavity having an accommodation space and a cavity top; a radio frequency electrode connected to the cavity top; a stage located in the accommodation space and configured to carry at least one substrate; an electrode connected to the stage; a gas dispersion ring connected to the cavity through at least one fastening member, the gas dispersion ring having a plurality of pores for introducing a process gas into the accommodation space, wherein the surface of the gas dispersion ring is subjected to roughening treatment and non-conductive treatment to form an uneven surface for attaching dirt of the cavity; and a partition ring below the gas dispersion ring, wherein the partition ring and the cavity enclose a partition space, the fastening member is located in the partition space, and the pores of the gas dispersion ring are restricted outside the partition space; wherein the partition ring further includes a connecting portion, a side surface and a bottom surface, the connecting portion is connected to the gas dispersion ring, the side surface is connected to the connecting portion, the bottom surface is connected to the side surface, and the connecting portion and the bottom surface are opposite to each other, wherein the side surface is configured to block dirt falling from the fastening member from falling onto the surface of the substrate, and the bottom surface is configured to receive the dirt, wherein a first distance is provided between one end of the bottom surface and the side wall of the cavity, and a second distance is provided between the fastening member and the side wall, wherein the first distance is less than the second distance.

3. The plasma cleaning device according to claim 1, wherein, Wherein the surface of the gas dispersion ring further includes a plurality of convex portions adjacent to the reaction space for attaching dirt of the cavity.

4. The plasma cleaning device according to claim 1 or 2, characterized in that, Wherein the roughening treatment is chemical roughening treatment, mechanical roughening treatment or organic solvent roughening treatment, and the non-conductive treatment is anodizing treatment.

5. The plasma cleaning device according to claim 1 or 2, characterized in that, The surface roughness (Ra) of the surface of the gas dispersion ring is 8 to 12 micrometers (μm).

6. The plasma cleaning device according to claim 1, wherein The plasma cleaning device further includes a vacuum pumping system, which is connected to the accommodation space of the cavity to extract the fluid in the accommodation space.

7. The plasma cleaning device according to claim 1, wherein The plasma cleaning device further includes a first baffle plate, which is located in the accommodation space and adjacent to the top of the cavity, and the first baffle plate has a plurality of first openings to form an uneven bottom surface.

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