TWI899718B - Plasma edge etching equipment - Google Patents

Abstract

The present invention discloses a plasma edge etching apparatus comprising a vacuum reaction chamber containing a movable upper electrode assembly or lower electrode assembly, the lower electrode assembly being used to support a substrate; an annular plasma confinement unit disposed radially outward from the substrate to confine plasma formed around the substrate; and an exhaust channel connecting the inner and outer sides of the plasma confinement unit. The advantages of plasma edge etching equipment are: a plasma confinement unit is provided to limit the plasma around the substrate, distributing the plasma evenly around the substrate and improving the cleaning effect; in addition, an exhaust channel is provided to control the exhaust. At the same time, the exhaust channel also increases the probability of plasma extinguishing in the exhaust channel, reducing damage to components in non-reactive areas and increasing the service life of the equipment.

Description

Plasma edge etching equipment

The present invention relates to the field of semiconductor equipment, and in particular to a plasma edge etching device.

Currently, processes such as plasma etching, physical vapor deposition, and chemical vapor deposition are commonly used to microfabricate semiconductor components or substrates, such as in the manufacture of flexible displays, flat-panel displays, light-emitting diodes, and solar cells. Various steps in microfabrication can include plasma-assisted processes, typically performed within a vacuum chamber. Among these processes, plasma edge etching (PEE) is used to clean the edges of substrates, reducing contamination of the chamber by byproducts accumulated along the edges.

During substrate edge etching, multiple process conditions influence the edge etching results, including the process gas flow within the reaction chamber, plasma distribution, process gas temperature distribution, substrate heating temperature field, and pressure distribution within the reaction chamber. If the process environment within the reaction zone within the reaction chamber is not completely uniform, uneven substrate surface treatment (e.g., uneven treatment depth, uneven composition, and uneven physical properties) can result, reducing substrate production yield. However, in practical applications, the process environment within a vacuum reaction chamber is often complex, making it difficult to achieve optimal coordination of these factors. Therefore, it is necessary to improve the existing plasma edge etching equipment in order to meet the actual process requirements.

It will be understood that the above description only provides background technology related to the present invention and does not necessarily constitute prior art.

The present invention aims to provide a plasma edge etching apparatus. A plasma confinement unit is provided in the plasma edge etching apparatus to confine the plasma around a substrate, distributing the plasma evenly around the substrate and improving the cleaning effect. Furthermore, the plasma edge etching apparatus is provided with an exhaust channel to control the exhaust flow. This exhaust channel also increases the probability of plasma extinguishing within the exhaust channel, reducing damage to components in non-reactive areas and increasing the service life of the apparatus.

In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

A plasma edge etching apparatus comprises: A vacuum reaction chamber containing a movable upper electrode assembly or lower electrode assembly, wherein the lower electrode assembly is used to support a substrate, the upper electrode assembly including an upper electrode ring, and the lower electrode assembly including a lower electrode ring, the upper and lower electrode rings being disposed opposite each other; A plasma confinement unit disposed around the substrate to confine plasma formed around the substrate; and an exhaust channel connecting the inner and outer sides of the plasma confinement unit.

Optionally, the exhaust channel is formed on the lower surface, upper surface or a portion between the upper and lower surfaces of the plasma confinement unit.

Optionally, the vacuum reaction chamber is unevenly provided with exhaust ports, and the exhaust capacity of the exhaust channel in the area close to the exhaust port is smaller than the exhaust capacity of the exhaust channel in the area far from the exhaust port.

Optionally, the plasma confinement unit is mounted on the lower surface of the upper electrode ring or the radial outer side of the upper electrode ring, and the exhaust channel is formed on the plasma confinement unit; during the process, there is a gap between the plasma confinement unit and the lower electrode assembly, and the exhaust inlet of the exhaust channel is higher than the plane where the substrate is located in the vertical direction.

Optionally, at least part of the plasma confinement unit is composed of an inner annular wall and an outer annular wall, and the exhaust channel is configured by the inner annular wall and the outer annular wall, wherein the inner annular wall and the outer annular wall are separated by an annular groove, an inner ring opening is provided on the inner annular wall, and an outer ring opening is provided on the outer annular wall.

Optionally, the inner ring opening and the outer ring opening are evenly distributed in the circumferential direction.

Optionally, the inner ring opening and the outer ring opening are staggered in the radial direction.

Optionally, the inner ring opening and the outer ring opening are arranged correspondingly in the radial direction, and a baffle structure is arranged in the annular groove, and the baffle structure is arranged between the inner ring opening and the outer ring opening.

Optionally, the baffle structure is fixedly connected to the lower electrode assembly.

Optionally, exhaust ports are unevenly distributed on the vacuum reaction chamber, and the baffle structure in the area close to the exhaust ports has a greater resistance to exhaust than the baffle structure in the area far from the exhaust ports.

Optionally, the lower electrode assembly further includes a shielding ring, which is used to cover at least a portion of the surface of the lower electrode ring.

Optionally, the plasma confinement unit and the shielding ring are integrated.

Optionally, there is a gap between the plasma confinement unit and the upper electrode assembly, the exhaust channel is formed on the plasma confinement unit, and during the process, the exhaust inlet of the exhaust channel is lower than the plane where the substrate is located in the vertical direction.

Optionally, the shielding ring only partially shields the lower electrode ring, and the outer diameter of the shielding ring is larger than the outer diameter of the lower electrode ring, and the plasma confinement unit is located outside the inner diameter of the shielding ring in the radial direction.

Optionally, the exhaust channel is an exhaust hole, a wave structure or a broken line structure.

Optionally, the upper electrode assembly includes a mounting plate connected to the upper electrode ring, and the plasma confinement unit is mounted on the lower surface of the mounting plate.

Optionally, the plasma confinement unit is made of one or more materials selected from the group consisting of quartz, ceramics, and metals with surface-attached dielectric materials.

Optionally, the surface of the plasma confinement unit comprises at least one of a Teflon film layer, a yttrium oxide film layer or an anodic oxide layer.

Compared with existing technologies, the present invention has the following advantages: In a plasma edge etching device of the present invention, a plasma confinement unit disposed at the periphery of a substrate is combined with an exhaust channel. The plasma confinement unit restricts the plasma around the substrate, distributing the plasma evenly around the substrate and improving the cleaning effect. In addition, the plasma edge etching device is also provided with an exhaust channel to control the exhaust. At the same time, the exhaust channel increases the probability of plasma extinguishing in the exhaust channel, reducing damage to components in non-reactive areas caused by the plasma and increasing the service life of the device.

Furthermore, the annular groove of the plasma confinement unit includes a baffle structure. The change in the baffle structure increases the travel path of gaseous matter discharged from the inner side of the plasma confinement unit, increases the number of collisions between charged particles of the plasma in the gaseous matter, and thus confines the plasma within the plasma confinement unit.

Furthermore, the plasma confinement unit is connected to the upper electrode assembly or the lower electrode assembly, which improves its operational stability and reduces the impact of gaseous substances on it.

To further clarify the objectives, technical solutions, and advantages of the embodiments of the present invention, the following provides a clear and complete description of the technical solutions of the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments are only a portion of the embodiments of the present invention, but not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without further development are also within the scope of protection of the present invention.

It should be noted that, in this document, the terms "comprise," "include," "have," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, the elements defined by the phrase "comprise..." or "comprising..." do not exclude the presence of additional elements in the process, method, article, or terminal device that includes the elements.

It should be noted that the drawings are all in very simplified form and use non-precise ratios, and are only used to conveniently and clearly assist in explaining the embodiments of the present invention.

As shown in FIG1 , a plasma edge etching apparatus according to the present invention comprises a vacuum reaction chamber 100, which is formed by a reaction chamber body and a chamber top 101. The reaction chamber body is typically made of a metal material and includes chamber sidewalls 102 and a chamber bottom 103. A substrate transfer port (not shown) is provided on the chamber sidewall 102. The substrate transfer port is used to transfer substrates W between the inside and outside of the vacuum reaction chamber 100. A lower electrode assembly 110 is provided within the vacuum reaction chamber 100 and is disposed at the bottom of the vacuum reaction chamber 100. The lower electrode assembly 110 is provided with a supporting surface, on which the substrate W to be processed, which is transferred into the vacuum reaction chamber 100, is placed. The vacuum reaction chamber 100 further includes an upper electrode assembly 120 disposed opposite the lower electrode assembly 110. The upper electrode assembly 120 is located at the top of the vacuum reaction chamber 100. Optionally, the upper electrode assembly 120 and/or the lower electrode assembly 110 can move up and down. When transferring a substrate W into and out of the vacuum reaction chamber 100, the upper electrode assembly 120 or the lower electrode assembly 110 is adjusted to increase the distance between the two to facilitate the transfer and placement of the substrate W. When processing the substrate W after transfer, the upper electrode assembly 120 or the lower electrode assembly 110 is adjusted to reduce the distance between the upper surface of the substrate W and the upper electrode assembly 120 to facilitate edge etching.

Continuing with Figure 1 , in this embodiment, the upper electrode assembly 120 comprises a mounting plate 121, an insulating isolation portion 122, an upper edge ring 123, and an upper electrode ring 124. The insulating isolation portion 122, upper edge ring 123, and upper electrode ring 124 are all disposed on the bottom of the mounting plate 121. The insulating isolation portion 122 is positioned opposite the center region of the substrate W and can be either a layered structure or a bulk structure. In this embodiment, the insulating isolation portion 122 is a ceramic plate. The upper edge ring 123 is disposed around the outer side of the insulating isolation portion 122, and the upper electrode ring 124 is disposed around the outer side of the upper edge ring 123. The upper electrode ring 124 is disposed above the edge region of the substrate W. The lower electrode assembly 110 includes a base 111, a lower edge ring 112, and a lower electrode ring 113. The lower edge ring 112 is disposed around the outer side of the base 111, and the lower electrode ring 113 is disposed around the outer side of the lower edge ring 112. The lower electrode ring 113 is disposed in the edge region of the substrate W. The lower electrode ring 113 and the upper electrode ring 124 are disposed opposite to each other. During the process, plasma is generated in the substrate edge region between the upper electrode ring 124 and the lower electrode ring 113 to perform edge etching.

Process gas or purge gas from one or more gas delivery devices 130 is introduced into the interior of the vacuum reaction chamber 100 via the gas distribution system of the top electrode assembly 120. The gas distribution system includes an edge gas inlet channel 125 and a central gas inlet channel 126. The edge gas inlet channel 125 includes a plurality of edge spray ports evenly distributed along the edge region of the substrate W to inject a first gas above the edge region of the substrate W. The central gas inlet channel 126 includes a plurality of central spray ports located above the central region of the substrate W to inject a second gas above the central region of the substrate W. Typically, during an edge etching process, the first gas introduced through the edge inlet channel 125 includes an etching gas containing F (fluorine), Cl (chlorine), a cleaning gas containing _O₂ (oxygen), and other auxiliary etching gases, thereby generating plasma to remove deposits from the edge, back, and bevel surfaces of the substrate W. The second gas introduced through the central inlet channel 126 includes a buffer gas or purge gas. The buffer gas is used to maintain a high pressure above the substrate W during edge processing, thereby protecting the central region of the substrate W from plasma etching.

At least one radio frequency power source is applied to at least one of the lower electrode assembly 110 and the upper electrode assembly 120 through a matching network to dissociate the process gas (first gas) into plasma, generating plasma between the upper electrode ring 124 and the lower electrode ring 113. The plasma is used to etch the edge of the substrate W. Specifically, the plasma contains a large number of active species, such as electrons, ions, excited atoms, molecules, and free radicals. These active species can undergo various physical and/or chemical reactions with the surface of the substrate W to be processed, causing changes in the morphology of the edge of the substrate W to be processed, thereby completing the processing of the edge of the substrate W to be processed.

Furthermore, the vacuum reaction chamber 100 is provided with an exhaust port 104, through which a vacuum extraction device exhausts the gas and reaction byproducts within the vacuum reaction chamber 100 to the outside of the chamber. Optionally, the vacuum extraction device may be a molecular pump, a dry pump, or a vacuum pump assembly. Of course, the vacuum extraction device is not limited to these types and may be any other device capable of achieving the same function.

In practical applications, due to the need to consider the rationality of the overall structural layout, the exhaust port 104 is typically not located directly below the vacuum reaction chamber 100, but rather offset to one side of the chamber bottom (typically located on the chamber bottom wall 103). The vacuum extraction device exhausts byproducts generated during the process out of the vacuum reaction chamber 100 through the exhaust port 104 on one side. During this process, because the exhaust port 104 is offset to one side of the chamber, the exhaust efficiency is higher near the exhaust port 104. The residence time of process gases and/or byproducts at different locations/positions above the substrate W varies, resulting in different plasma concentration distributions at different locations above the substrate W. This leads to a biased etching rate at the substrate W, which can easily cause uneven etching at the edges of the substrate W. On the other hand, during operation, due to the relatively small gap between the bottom surface of the upper electrode assembly 120 and the substrate W, the process gas delivered to the vacuum reaction chamber 100 through the edge spray port of the edge gas inlet channel 125 may be drawn out before it has time to diffuse, resulting in a localized area devoid of gas and causing uneven distribution. This further leads to uneven plasma distribution above the substrate W, affecting the etching effect at the edge of the substrate W.

Based on the above, the plasma edge etching apparatus is further provided with an annular plasma confinement unit 140. The plasma confinement unit 140 is disposed radially outwardly of the substrate W to confine the plasma formed around the substrate W. By providing the plasma confinement unit 140, the process gas and/or plasma can be confined to a relatively small space, which is more conducive to uniform plasma distribution and improved edge etching efficiency. In addition, the plasma edge etching apparatus further includes an exhaust channel connecting the interior and exterior of the plasma confinement unit 140. This exhaust channel is used to exhaust reaction byproducts, plasma, and residual gases from the area enclosed by the plasma confinement unit 140 out of the vacuum reaction chamber 100. This exhaust channel not only facilitates controlling the exhaust rate at the edge of the substrate W but also increases the probability of quenching the extracted plasma, preventing plasma from leaking into non-reactive areas such as the chamber sidewalls and potentially damaging components in these areas.

Optionally, the exhaust channel near the exhaust port 104 has a lower exhaust capacity than the exhaust channel far from the exhaust port 104, thereby reducing the impact of the exhaust port 104 on the gas distribution at the edge of the substrate W and improving the uniformity of the gas distribution at different circumferential locations of the substrate W. In practical applications, by optimizing the plasma confinement unit 140 and the exhaust channel, it is possible to balance the device's exhaust capacity and plasma confinement capabilities while ensuring environmental uniformity around the substrate W.

Optionally, the exhaust channel is formed on the lower surface, upper surface, or a portion between the upper and lower surfaces of the plasma confinement unit 140 so as to discharge the reaction byproducts above the substrate W in a timely manner.

Furthermore, the plasma confinement unit 140 is mounted on the lower surface of the upper electrode ring 124 or the radial outer side of the upper electrode ring 124, the exhaust channel is formed on the plasma confinement unit 140, and during the process, there is a gap between the plasma confinement unit 140 and the lower electrode assembly 110, and the exhaust inlet of the exhaust channel is higher than the plane of the substrate W in the vertical direction.

As shown in Figures 2 and 3, in this embodiment, the plasma confinement unit 140 is installed on the lower surface of the upper electrode ring 124, and at least a portion of the plasma confinement unit 140 is composed of an inner annular wall 141 and an outer annular wall 142 surrounding the inner annular wall 141. The exhaust channel is configured by the inner annular wall 141 and the outer annular wall 142, wherein the inner annular wall 141 and the outer annular wall 142 are separated by an annular groove 143. An inner ring opening 144 is provided on the inner annular wall 141, and an outer ring opening 145 is provided on the outer annular wall 142. The inner ring opening 144 and the outer ring opening 145 respectively form an exhaust inlet and an exhaust outlet of the exhaust channel. During the process, gaseous substances such as reaction by-products and plasma enter the annular groove 143 through the inner ring opening 144 and are then discharged through the outer ring opening 145 to the exhaust path connected to the exhaust port 104.

Optionally, the inner annular wall 141 and the outer annular wall 142 are integrally formed, though other structures are also possible, and the present invention is not limited thereto. Furthermore, the inner annular wall 141 includes multiple inner ring openings 144 evenly distributed circumferentially, while the outer annular wall 142 includes multiple outer ring openings 145 evenly distributed circumferentially. Gaseous material from the edge of the substrate W is discharged through the circumferentially distributed inner ring openings 144. The exhaust channel formed by the openings (inner ring openings 144 and outer ring openings 145) ensures uniform circumferential distribution of gaseous material around the substrate W, facilitating uniform gaseous material transport and, consequently, ensuring effective etching of the substrate W edge.

As shown in FIG3 , in this embodiment, the inner ring opening 144 and the outer ring opening 145 are staggered in the radial direction. After the gaseous material on the inner side of the plasma confinement unit 140 enters the annular groove 143 through the inner ring opening 144, there is no corresponding outer ring opening 145 in the radial direction. The gaseous material collides with the inner surface of the outer ring wall 142 and then disperses to both sides, and then is discharged through the outer ring openings 145 on both sides. This method increases the travel path of the gaseous material and the contact with the plasma confinement unit 140. The probability of collision is increased. Such collisions will cause charged particles in the remaining plasma in the gaseous material to contact and collide with the inner surface of the outer annular wall 142, accelerating their annihilation. After the gaseous material disperses to both sides, some charged particles in the plasma will also collide and reflect between the outer surface of the inner annular wall 141 and the inner surface of the outer annular wall 142. Each collision will reduce the energy of the charged particles. It will be understood that in another embodiment, the inner ring opening 144 and the outer ring opening 145 are arranged in a radially corresponding direction. Such an arrangement can take into account both pumping efficiency and reducing the amount of plasma being pumped to other locations in the reaction chamber.

Furthermore, as shown in FIG1 , in this embodiment, the lower electrode assembly 110 further includes a shielding ring 114, which is used to cover at least a portion of the surface of the lower electrode ring 113. The lower electrode ring 113 is mounted and secured via a mechanical fastener (e.g., a bolt assembly). The shielding ring 114 protects the mechanical fastener from plasma corrosion, thereby increasing its service life. Furthermore, the exhaust channel is provided through the lower surface of the plasma confinement unit 140, i.e., the exhaust channel is formed by a recess in the lower surface of the plasma confinement unit 140, and the shielding ring 114 is located below the plasma confinement unit 140. In practical applications, the gaseous material exhausted from the inner side of the plasma confinement unit 140 may contain some particles and/or plasma, which will move downward during the process of being extracted from the aforementioned gap. Such movement will accelerate the corrosion of the lower electrode ring 113. To mitigate such corrosion, the shielding ring 114 only partially shields the lower electrode ring 113, and the outer diameter of the shielding ring 114 is larger than the outer diameter of the lower electrode ring 113. The plasma confinement unit 140 is radially located outside the inner diameter of the shielding ring 114. In this way, the downward movement of particles and/or plasma generated during the extraction of the aforementioned gap can act on the shielding ring 114, reducing the impact on the lower electrode ring 113.

Optionally, the plasma confinement unit 140 is made of one or more materials selected from quartz, ceramic, and metals with a dielectric material attached to their surfaces (e.g., aluminum). Of course, the plasma confinement unit 140 is not limited to the materials listed above; it can also be made of other materials, and this is not a limitation of the present invention. Furthermore, to enhance the durability of the plasma confinement unit 140 and ensure the cleanliness of the vacuum reaction chamber 100, a plasma-corrosion-resistant film is provided on the surface of the plasma confinement unit 140. Optionally, the plasma-corrosion-resistant film comprises at least one of a Teflon film, a yttrium oxide film, or an anodic oxide layer. It is understandable that the plasma corrosion resistant film layer may also include other materials as long as they can achieve the corresponding functions, and the present invention is not limited thereto.

It should be noted that the structure of the exhaust channel is not limited to the above-mentioned solution, and it can also be other structures as long as it can achieve its corresponding functions. The present invention does not impose any restrictions on this. For example, as shown in Figures 4 and 5, in another embodiment, the exhaust channel is an exhaust hole, that is, the plasma confinement unit 240 includes a plurality of grooves 241, and each groove 241 forms an exhaust hole. Gaseous substances such as process gas, plasma or reaction by-products pass through the exhaust hole and are discharged from the vacuum reaction chamber through the exhaust port. The side walls of the exhaust hole will reflect the charged particles in the plasma multiple times. Each reflection will reduce the energy of the charged particles and accelerate their annihilation, so as to annihilate them as much as possible in the plasma confinement unit 240, which helps to protect the components on the exhaust path from plasma corrosion, improve the service life of the components, and at the same time ensure the cleanliness of the interior of the cavity. In this embodiment, the side wall of the exhaust channel is a planar structure. In other embodiments, the side wall of the exhaust channel may also be a non-planar structure, such as a wavy structure or a broken line structure, which increases the contact area between the plasma and the side wall of the exhaust channel, while increasing the number of reflections of the plasma, accelerating plasma annihilation, and shortening the radial diffusion free path required for plasma annihilation.

Furthermore, the plasma confinement unit 240 is not limited to being connected to the upper electrode ring 124 of the upper electrode assembly 120, and can also be configured to be connected to other components of the upper electrode assembly 120. For example, in another embodiment, the plasma confinement unit 240 is mounted on the lower surface of the mounting plate 121 connected to the upper electrode ring 124.

Preferably, as shown in the combination of Figures 6 to 8 , an exhaust channel is provided in the plasma confinement unit 340. The exhaust channel is configured by an inner annular wall 341 having an inner ring opening 344 and an outer annular wall 342 having an outer ring opening 345. The inner annular wall 341 and the outer annular wall 342 are separated by an annular groove 343. Furthermore, the plasma confinement unit 340 further includes a baffle structure 346. Specifically, a plurality of baffle structures 346 are provided within the annular groove 343. The baffle structures 346 are disposed between at least one inner ring opening 344 and an outer ring opening 345. The inner ring opening 344 and the outer ring opening 345 are disposed in a radially corresponding manner. During operation, gaseous material entering the annular groove 343 from the inner ring opening 344 first collides with the baffle structure 346, then diffuses to both sides from the baffle structure 346 before being discharged from the plasma confinement unit 340 through the outer ring opening 345. The baffle structure 346 alters and increases the path of the gaseous material, increasing the number of collisions between charged plasma particles in the gaseous material and thereby confining the plasma within the plasma confinement unit 340.

Optionally, the baffle structure 346 is integrally formed with the inner annular wall 341 and the outer annular wall 342 as at least a portion of the plasma confinement unit 340. The exhaust channel formed by the baffle structure 346, the inner annular wall 341, and the outer annular wall 342 can be formed on the upper surface, the lower surface, or between the upper and lower surfaces of the plasma confinement unit 340. When the plasma confinement unit 340 is mounted on the upper electrode assembly 320 and the exhaust channel is formed on the lower surface of the plasma confinement unit 340, the baffle structure 346, the inner annular wall 341, and the outer annular wall 342 are all formed by depressions on the lower surface of the plasma confinement unit 340. It is understood that the baffle structure 346 is not limited to being formed in the plasma confinement unit 340. It can also be directly connected to the lower electrode assembly 310 and inserted between the inner annular wall 341 and the outer annular wall 342. Specifically, as shown in FIG8 , the baffle structure 346 is connected to the shielding ring 314 of the lower electrode assembly 310, and the inner annular wall 341 and the outer annular wall 342 of the plasma confinement unit 340 are connected to the upper electrode assembly 320. During the substrate W transfer process, the upper electrode assembly 320 or the lower electrode assembly 310 is moved to adjust the distance between the two, so that the substrate W passes between the bottom of the inner annular wall 341 and the outer annular wall 342 and the top of the baffle structure 346 and is placed on the base 311. After the transfer is completed, the upper electrode assembly 320 or the lower electrode assembly 310 is adjusted to reduce the distance between them. During this process, the baffle structure 346 is inserted into the annular groove 343. This allows the plasma to strike the plasma confinement unit 340 multiple times during the etching process at the edge of the substrate W, reducing the energy of the charged particles and preventing damage to the components in the pumping path. By adjusting the size of the openings on the inner annular wall 341 and outer annular wall 342 of the plasma confinement unit 340 and the baffle structure 346, the plasma confinement capability can be increased while satisfying the requirement for regulating vacuum pumping uniformity, thereby achieving coordinated optimal adjustment of various process conditions and helping to ensure better wafer processing results.

Optionally, the shielding area of the baffle structure 346 near the exhaust port 304 is larger than the shielding area of the baffle structure 346 far from the exhaust port 304. That is, the pumping resistance near the exhaust port 304 is greater than that far from the exhaust port 304. This ensures circumferential uniformity around the edge of the substrate W while balancing vacuum pumping and plasma confinement capabilities. The shielding area of the baffle structure 346 can be adjusted by adjusting the depth of the baffle structure 346 inserted into the annular groove 343, or by other means, and the present invention is not limited thereto. Furthermore, the sizes of the openings (inner ring openings 344 and outer ring openings 345) at various circumferential locations around the substrate W can be adjusted as needed to meet actual process requirements. For example, the openings near the exhaust port 304 (inner ring openings 344 and outer ring openings 345) are smaller than the openings farther from the exhaust port 304 (inner ring openings 344 and outer ring openings 345). In some embodiments, the amount of exhaust resistance can also be controlled by setting the number, size, or length of the exhaust channels.

In some embodiments, the plasma confinement unit may also be connected to the lower electrode assembly. The exhaust channel is provided on the plasma confinement unit. During the process, a gap exists between the plasma confinement unit and the upper electrode assembly, and the exhaust inlet of the exhaust channel is vertically lower than the plane of the substrate. The exhaust channel can be formed in the same manner as in the aforementioned embodiment.

In summary, in a plasma edge etching device of the present invention, a plasma confinement unit is provided to restrict the plasma around a substrate W, so that the plasma is evenly distributed around the substrate, thereby improving the cleaning effect. In addition, the device is also provided with an exhaust channel to control the exhaust. At the same time, the design of the exhaust channel increases the probability of plasma extinguishing in the exhaust channel, reduces plasma leakage into non-reactive areas, and avoids damage to components in non-reactive areas.

Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered a limitation of the present invention. Furthermore, the embodiments and the technical features therein may be combined, where there is no conflict. Such combined technical solutions should also be considered technical solutions described herein. After reading the above, various modifications and alternatives to the present invention will be readily apparent to those skilled in the art. Therefore, the scope of protection of the present invention shall be defined by the appended claims.

100: Vacuum reaction chamber 101: Chamber lid 102: Chamber sidewalls 103: Chamber bottom wall 104, 304: Exhaust port 110, 310: Lower electrode assembly 111, 311: Base 112: Lower edge ring 113: Lower electrode ring 114, 314: Shield ring 120, 320: Upper electrode assembly 121: Mounting plate 122: Insulation barrier 123: Upper edge ring 124: Upper electrode ring 125: Edge inlet channel 126: Center inlet channel 130: Gas delivery system 140, 240, 340: Plasma confinement unit 141, 341: Inner ring wall 142, 342: Outer ring wall 143, 343: Annular groove 144, 344: Inner ring opening 145, 345: Outer ring opening 241: Groove 346: Baffle structure W: Substrate

Figure 1 is a schematic diagram of the structure of a plasma edge etching apparatus provided in one embodiment of the present invention; Figure 2 is a cross-sectional view of a plasma confinement unit in the plasma edge etching apparatus provided in the present invention, taken along an exhaust channel; Figure 3 is a partially enlarged schematic diagram of the cross section of the plasma confinement unit in Figure 2; Figure 4 is a cross-sectional view of another plasma confinement unit in the plasma edge etching apparatus provided in the present invention, taken along an exhaust channel; Figure 5 is a partially enlarged schematic diagram of the cross section of the plasma confinement unit in Figure 4; Figure 6 is a cross-sectional view of another plasma confinement unit in the plasma edge etching apparatus provided in the present invention, taken along an exhaust channel; Figure 7 is a partially enlarged schematic diagram of the cross section of the plasma confinement unit in Figure 6; Figure 8 is a schematic diagram of the structure of a plasma edge etching device provided in another embodiment of the present invention.

100: Vacuum reaction chamber 101: Chamber top 102: Chamber sidewalls 103: Chamber bottom 104: Exhaust port 110: Lower electrode assembly 111: Base 112: Lower edge ring 113: Lower electrode ring 114: Shield ring 120: Upper electrode assembly 121: Mounting plate 122: Insulation barrier 123: Upper edge ring 124: Upper electrode ring 125: Edge inlet channel 126: Central inlet channel 130: Gas delivery device 140: Plasma confinement unit

Claims (18)

A plasma edge etching apparatus comprises: A vacuum reaction chamber having a movable upper electrode assembly or lower electrode assembly within the vacuum reaction chamber, the lower electrode assembly being used to support a substrate, the upper electrode assembly including an upper electrode ring, and the lower electrode assembly including a lower electrode ring, the upper and lower electrode rings being arranged opposite each other to generate plasma at the edge of the substrate between the upper and lower electrode rings; A plasma confinement unit disposed at the periphery of the substrate to confine the plasma formed around the substrate; and an exhaust channel connecting the inner and outer sides of the plasma confinement unit. The plasma edge etching apparatus of claim 1, wherein: The exhaust channel is formed on the lower surface, upper surface, or a portion between the upper and lower surfaces of the plasma confinement unit. The plasma edge etching apparatus of claim 2, wherein: The vacuum reaction chamber is provided with exhaust ports unevenly distributed, and the exhaust capacity of the exhaust channels in areas near the exhaust ports is less than the exhaust capacity of the exhaust channels in areas far from the exhaust ports. The plasma edge etching apparatus of claim 1, wherein: the plasma confinement unit is mounted on the lower surface of the upper electrode ring or radially outward of the upper electrode ring, and the exhaust channel is formed on the plasma confinement unit; during the process, a gap exists between the plasma confinement unit and the lower electrode assembly, and the exhaust inlet of the exhaust channel is vertically higher than the plane of the substrate. The plasma edge etching apparatus of claim 4, wherein: At least a portion of the plasma confinement unit is composed of an inner annular wall and an outer annular wall, and the exhaust passage is configured by the inner annular wall and the outer annular wall, wherein the inner annular wall and the outer annular wall are separated by an annular groove, the inner annular wall is provided with an inner ring opening, and the outer annular wall is provided with an outer ring opening. The plasma edge etching apparatus of claim 5, wherein: the inner ring openings and the outer ring openings are evenly distributed in the circumferential direction. The plasma edge etching apparatus of claim 6, wherein: the inner ring opening and the outer ring opening are radially offset. The plasma edge etching apparatus of claim 5, wherein: the inner ring opening and the outer ring opening are radially opposed to each other, and a baffle structure is disposed within the annular groove, the baffle structure being disposed between the inner ring opening and the outer ring opening. The plasma edge etching apparatus of claim 8, wherein: the baffle structure is fixedly connected to the lower electrode assembly. The plasma edge etching apparatus of claim 8, wherein: The vacuum reaction chamber is provided with exhaust ports unevenly distributed, and the baffle structure in areas near the exhaust ports provides greater resistance to exhaust than the baffle structure in areas farther from the exhaust ports. The plasma edge etching apparatus of claim 1, wherein: The lower electrode assembly further includes a shielding ring configured to cover at least a portion of the surface of the lower electrode ring. The plasma edge etching apparatus of claim 11, wherein: the plasma confinement unit is integrally provided with the shielding ring. The plasma edge etching apparatus of claim 11, wherein: a gap exists between the plasma confinement unit and the upper electrode assembly; the exhaust channel is formed on the plasma confinement unit; and during the process, the exhaust inlet of the exhaust channel is vertically lower than the plane of the substrate. The plasma edge etching apparatus of claim 11, wherein: the shielding ring only partially shields the lower electrode ring, the outer diameter of the shielding ring is larger than the outer diameter of the lower electrode ring, and the plasma confinement unit is radially located outside the inner diameter of the shielding ring. The plasma edge etching apparatus of claim 1, wherein: The exhaust channel is a through-hole, a wavy structure, or a broken-line structure. The plasma edge etching apparatus of claim 1, wherein: the upper electrode assembly includes a mounting plate connected to the upper electrode ring, and the plasma confinement unit is mounted on a lower surface of the mounting plate. The plasma edge etching apparatus of claim 1, wherein: The plasma confinement unit is made of one or more materials selected from the group consisting of quartz, ceramic, and metal with a dielectric material attached to the surface. The plasma edge etching apparatus of claim 1, wherein: The surface of the plasma confinement unit comprises at least one of a Teflon film layer, a yttrium oxide film layer, or an anodic oxide layer.