CN118263080A - Plasma edge etching equipment - Google Patents

Abstract

The invention discloses a plasma edge etching device, which comprises: the vacuum reaction chamber is internally provided with a movable upper electrode assembly or a movable lower electrode assembly, the movable upper electrode assembly or the movable lower electrode assembly respectively comprise an upper electrode ring and a lower electrode ring which are oppositely arranged, and the movable upper electrode assembly or the movable lower electrode assembly are used for supporting a substrate; the annular plasma confining unit is arranged at the radial periphery of the substrate and used for confining plasma formed around the substrate; and an air exhaust channel communicated with the inner side and the outer side of the plasma confinement unit. The advantages are that: the plasma restraining unit arranged in the device limits plasmas around the substrate, so that the plasmas are uniformly distributed around the substrate, and the cleaning effect is improved; in addition, the device is also provided with an air extraction channel to control air extraction, and meanwhile, the air extraction channel also increases the extinguishing probability of plasma in the air extraction channel, reduces the damage of the plasma to parts in a non-reaction area, and prolongs the service life of equipment.

Description

Plasma edge etching equipment

Technical Field

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

Background

At present, processes such as plasma etching, physical vapor deposition, chemical vapor deposition and the like are generally adopted to carry out micromachining on semiconductor process parts or substrates, such as flexible display screens, flat panel displays, light emitting diodes, solar cells and the like. The various steps of micromachining fabrication may include plasma-assisted processes, which are typically performed in vacuum reaction chambers. The plasma edge etching process in the plasma auxiliary process is used for cleaning the edge of the substrate so as to reduce pollution of byproducts accumulated on the edge of the substrate to the reaction cavity.

In the process of performing edge etching on a substrate, various process conditions affect the effect of edge etching, such as flow of process gas in a reaction chamber, distribution of plasma, temperature distribution of process gas, heating temperature field of the substrate, pressure distribution in the reaction chamber, and the like. If the process environment of the reaction area in the reaction cavity is not completely consistent, the phenomenon of uneven substrate surface treatment effect (such as uneven substrate surface treatment depth, uneven components and uneven physical characteristics) can be caused, so that the yield of substrate production is reduced. However, in practical application, the process environment in the vacuum reaction chamber is often complex, and it is difficult to realize the optimal condition coordination of various factors. Accordingly, improvements to existing plasma edge etching apparatus are needed to meet the full real process requirements.

It is to be understood that the foregoing is merely illustrative of the background art to which the present invention pertains and is not necessarily a representation of the prior art.

Disclosure of Invention

The invention aims to provide plasma edge etching equipment, wherein a plasma restraint unit arranged in the device limits plasmas around a substrate, so that the plasmas are uniformly distributed around the substrate, and the cleaning effect is improved; in addition, the device is also provided with an air extraction channel to control air extraction, and meanwhile, the air extraction channel also increases the extinguishing probability of plasma in the air extraction channel, reduces the damage of the plasma to parts in a non-reaction area, and prolongs the service life of equipment.

In order to achieve the above purpose, the present invention is realized by the following technical scheme:

a plasma edge etching apparatus comprising:

A vacuum reaction chamber, wherein a movable upper electrode assembly or a lower electrode assembly is arranged in the vacuum reaction chamber, the lower electrode assembly is used for supporting a substrate, the upper electrode assembly comprises an upper electrode ring, the lower electrode assembly comprises a lower electrode ring, and the upper electrode ring and the lower electrode ring are oppositely arranged;

the plasma restraint unit is arranged at the periphery of the substrate and used for restraining plasma formed around the substrate; and an air exhaust channel communicated with the inner side and the outer side of the plasma confinement unit.

Optionally, the pumping channel is formed at a lower surface, an 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 an exhaust port, and the pumping capacity of the pumping channel in a region close to the exhaust port is smaller than that of the pumping channel in a region far away from the exhaust port.

Optionally, the plasma confinement unit is mounted on the lower surface of the upper electrode ring or on the radial outer side of the upper electrode ring, and the air 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 air suction inlet of the air suction channel is higher than the plane of the substrate 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 air 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 spaced apart through an annular groove, an inner ring opening is formed in the inner annular wall, and an outer ring opening is formed in the outer annular wall.

Optionally, the inner ring openings and the outer ring openings are uniformly distributed in the circumferential direction.

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

Optionally, the inner ring opening and the outer ring opening are correspondingly arranged in the radial direction, 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 with the lower electrode assembly.

Optionally, the vacuum reaction chamber is unevenly provided with an exhaust port, and the resistance of the baffle structure in the area close to the exhaust port to air suction is greater than that in the area far away from the exhaust port.

Optionally, the lower electrode assembly further comprises a shielding ring for covering at least part of the surface of the lower electrode ring.

Optionally, the plasma confinement unit is integrally disposed with the shielding ring.

Optionally, a gap exists between the plasma confinement unit and the upper electrode assembly, the pumping channel is formed on the plasma confinement unit, and during the process, a pumping inlet of the pumping channel is lower than the plane of the substrate 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 air extraction channel is an air extraction through hole, a wave structure or a fold 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 a lower surface of the mounting plate.

Optionally, the preparation material of the plasma confinement unit comprises one or more of quartz, ceramic, and metal with a dielectric material attached to the surface.

Optionally, the surface of the plasma confinement unit comprises at least one of a teflon film layer, a yttria film layer, or an anodized layer.

Compared with the prior art, the invention has the following advantages:

In the plasma edge etching equipment, the plasma restraint unit and the air exhaust channel are combined, wherein the plasma restraint unit is arranged at the periphery of the substrate and is used for limiting plasma around the substrate, so that the plasma is uniformly distributed around the substrate, and the cleaning effect is improved; in addition, the device is also provided with an air extraction channel to control air extraction, and meanwhile, the air extraction channel also increases the extinguishing probability of plasma in the air extraction channel, reduces the damage of the plasma to parts in a non-reaction area, and prolongs the service life of equipment.

Further, the annular groove of the plasma confinement unit is internally provided with a baffle structure, the baffle structure changes the walking path of the gaseous substances discharged outwards from the inner side of the plasma confinement unit, and the impact times of charged particles of the plasma in the gaseous substances are increased, so that the plasma is confined in the plasma confinement unit.

Furthermore, the plasma confinement unit is connected with the upper electrode assembly or the lower electrode assembly, so that the use stability of the plasma confinement unit is improved, and the impact of gaseous substances on the plasma confinement unit is reduced.

Drawings

FIG. 1 is a schematic diagram of a plasma edge etching apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a plasma confinement unit along a pumping channel in a plasma edge etching apparatus according to the present invention;

FIG. 3 is an enlarged partial schematic view of a cross section of the plasma confinement unit of FIG. 2;

FIG. 4 is a cross-sectional view of yet another plasma confinement unit along the pumping channel in the plasma edge etching apparatus provided by the present invention;

FIG. 5 is an enlarged partial schematic view of a cross section of the plasma confinement unit of FIG. 4;

FIG. 6 is a cross-sectional view of yet another plasma confinement unit along the pumping channel in the plasma edge etching apparatus provided by the present invention;

FIG. 7 is an enlarged partial schematic view of a cross section of the plasma confinement unit of FIG. 6;

fig. 8 is a schematic structural diagram of a plasma edge etching apparatus according to another embodiment of the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that, in this document, the terms "comprises," "comprising," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal device. Without further limitation, an element defined by the statement "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal device that includes the element.

It is noted that the drawings are in a very simplified form and utilize non-precise ratios, and are intended to facilitate a convenient, clear, description of the embodiments of the invention.

As shown in fig. 1, a plasma edge etching apparatus of the present invention comprises: a vacuum reaction chamber 100 is surrounded by a reaction chamber cavity, typically made of a metallic material, comprising a chamber side wall 102 and a chamber bottom wall 103, and a chamber top cover 101. The chamber sidewall 102 is provided with a substrate transfer port (not shown) for transferring the substrate W between the inside and the outside of the vacuum reaction chamber 100. The vacuum reaction chamber 100 is internally provided with a lower electrode assembly 110, which is arranged at the bottom of the vacuum reaction chamber 100, the lower electrode assembly 110 is provided with a bearing surface, and the substrate W to be processed introduced into the vacuum reaction chamber 100 is placed on the bearing surface. The vacuum reaction chamber 100 further comprises an upper electrode assembly 120 disposed opposite to the lower electrode assembly 110, and the upper electrode assembly 120 is disposed at the top of the vacuum reaction chamber 100. Alternatively, the upper electrode assembly 120 and/or the lower electrode assembly 110 may move up and down. When the substrate W is transferred 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 interval therebetween so as to facilitate the transfer and placement of the substrate W; when the substrate W is processed after the 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 so that the edge etching process is performed.

With continued reference to fig. 1, in this embodiment, the upper electrode assembly 120 includes a mounting plate 121, an insulating spacer 122, an upper edge ring 123, and an upper electrode ring 124. The insulating isolation part 122, the upper edge ring 123 and the upper electrode ring 124 are all disposed at the bottom of the mounting plate 121, the insulating isolation part 122 is disposed opposite to the central region of the substrate W, and the insulating isolation part 122 may be a layer structure or a body structure. In this embodiment, the insulating spacer 122 is a ceramic plate. The upper edge ring 123 is disposed around the outer side of the insulating spacer 122, the upper electrode ring 124 is disposed around the outer side of the upper edge ring 123, and 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, the lower electrode ring 113 is disposed around the outer side of the lower edge ring 112, and 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, and plasma is generated at an edge region of the substrate between the upper electrode ring 124 and the lower electrode ring 113 to perform edge etching during a process.

The process gas or purge gas in the 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 upper electrode assembly 120. The gas distribution system comprises an edge gas inlet channel 125 and a central gas inlet channel 126, the edge gas inlet channel 125 comprising a plurality of edge shower ports, each edge shower port being uniformly distributed along an edge region of the substrate W for injecting a first gas over the edge region of the substrate W. The central gas inlet channel 126 contains a number of central shower ports that are positioned above the central region of the substrate W to inject the second gas above the central region of the substrate W. Typically, in the edge etching process, the first gas introduced into the edge gas inlet channel 125 includes an etching gas containing F, cl, etc. and a cleaning gas containing O ₂, etc. and other auxiliary etching gases, so as to generate plasma to remove the deposits on the edge, the back surface and the bevel of the substrate W. The second gas introduced through the central gas inlet channel 126 contains a buffer gas or a purge gas, which is used to maintain a high pressure above the substrate W during the edge processing of the substrate W, so as to prevent the etching of the central region of the substrate W from plasma.

At least one radio frequency power is applied to at least one of the lower electrode assembly 110 and the upper electrode assembly 120 through a matching network to dissociate a process gas (first gas) into a plasma, which is used to etch the edge of the substrate W, such that a plasma is generated between the upper electrode ring 124 and the lower electrode ring 113. Specifically, the plasma contains a large amount of active particles such as electrons, ions, atoms in an excited state, molecules, free radicals and the like, and the active particles can react with the surface of the substrate W to be processed in various physical and/or chemical ways, so that the appearance of the edge of the substrate W to be processed is changed, and the processing of the edge of the substrate W to be processed is completed.

Further, the vacuum reaction chamber 100 is provided with an exhaust port 104, and a vacuum extraction device exhausts the gas and the reaction byproducts inside the vacuum reaction chamber 100 to the outside of the chamber through the exhaust port 104. Alternatively, the vacuum pumping device may be a molecular pump or a dry pump or a vacuum pump group, and of course, the type of the vacuum pumping device is not limited thereto, and may be any other device capable of achieving the same function.

In practical applications, because of the reasonable arrangement of the whole structure, the exhaust port 104 is not usually located under the vacuum reaction chamber 100, but is biased to one side of the bottom of the chamber (usually disposed on the bottom wall 103 of the chamber), and the vacuum extraction device extracts byproducts generated in the process to the outside of the vacuum reaction chamber 100 through the exhaust port 104 on one side. In this process, since the exhaust port 104 is biased toward one side of the chamber, the pumping efficiency is higher near the exhaust port 104, and the residence time of the process gas and/or by-products in different orientations/positions over the substrate W is not uniform, so that the plasma concentration distribution in different orientations over the substrate W is different, resulting in a biased etching rate of the substrate W, which is prone to uneven etching of the edge of the substrate W. On the other hand, in the operating state, since the gap between the bottom surface of the upper electrode assembly 120 and the substrate W is small, the process gas supplied from the edge shower port of the edge gas inlet channel 125 to the vacuum reaction chamber 100 may be pumped away as soon as it is diffused, so that there is no gas in the local area, which results in uneven distribution, further resulting in uneven plasma distribution over the substrate W, which affects the edge etching effect of the substrate W.

Based on the above, the plasma edge etching apparatus is further provided with an annular plasma confinement unit 140, where the plasma confinement unit 140 is disposed at the radial periphery of the substrate W to confine the plasma formed around the substrate W, and by disposing the plasma confinement unit, the process gas and/or the plasma can be confined in a relatively small space, which is more beneficial to making the plasma uniformly distributed and improving the edge etching efficiency. In addition, the plasma edge etching apparatus further comprises a pumping channel communicating the inner side and the outer side of the plasma confinement unit 140, wherein the pumping channel is used for exhausting reaction byproducts, plasma and residual gas in the surrounding area of the inner side of the plasma confinement unit 140 out of the vacuum reaction chamber 100. The air suction channel is not only beneficial to controlling the air suction rate of the edge of the substrate W, but also can increase the probability of extinguishing the plasma which is sucked away, prevent the plasma from leaking to non-reaction areas such as the side wall of the chamber and the like, and avoid damage to parts of the corresponding non-reaction areas.

Optionally, the air extraction capacity of the air extraction channel near the area of the air outlet 104 is smaller than that of the air extraction channel far away from the area of the air outlet 104, so as to weaken the influence of the air outlet 104 on the gas distribution at the edge of the substrate W, and improve the uniformity of the gas distribution in different circumferential directions of the substrate W. In practical application, through different optimization designs of the plasma confining unit 140 and the air extracting channel, the air extracting capability and the plasma confining capability of the device can be balanced, and meanwhile, the circumferential environmental uniformity of the substrate W can be ensured.

Optionally, the pumping channel is formed at a lower surface, an upper surface, or a portion between the upper and lower surfaces of the plasma confinement unit 140 so as to timely discharge the reaction byproducts over the substrate W.

Further, the plasma confining unit 140 is mounted on the lower surface of the upper electrode ring 124 or on the radial outer side of the upper electrode ring 124, and the pumping channel is formed on the plasma confining unit 140, and a gap exists between the plasma confining unit 140 and the lower electrode assembly 110 during the process, and the pumping inlet of the pumping channel is vertically higher than the plane of the substrate W.

As shown in fig. 2 and 3, in the present embodiment, the plasma confining unit 140 is mounted on the lower surface of the upper electrode ring 124, at least part of the plasma confining unit 140 is composed of an inner annular wall 141 and an outer annular wall 142 surrounding the inner annular wall 141, and the pumping 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 spaced apart by an annular groove 143, an inner annular opening 144 is formed in the inner annular wall 141, an outer annular opening 145 is formed in the outer annular wall 142, and pumping inlets and pumping outlets of the pumping channel are respectively formed by the inner annular opening 144 and the outer annular opening 145. During the process, gaseous materials such as reaction byproducts, plasma, etc. enter annular groove 143 from inner ring opening 144 and are exhausted through outer ring opening 145 to an exhaust path in communication with exhaust port 104.

Alternatively, the inner annular wall 141 and the outer annular wall 142 are integrally formed, but may be formed in other structures, which is not limited thereto. Further, the inner ring openings 144 formed in the inner ring wall 141 are uniformly distributed in the circumferential direction, the outer ring openings 145 formed in the outer ring wall 142 are uniformly distributed in the circumferential direction, the gaseous substances in the edge region of the substrate W are discharged through the inner ring openings 144 distributed in the circumferential direction, and the uniformity of the distribution of the gaseous substances in the circumferential direction of the substrate W can be ensured through the air suction channels formed by the openings (144, 145) and the like, so that the uniformity of the conveying of the gaseous substances is ensured, and the effect of etching the edge of the substrate W is ensured.

As shown in fig. 3, in the present embodiment, the inner ring opening 144 and the outer ring opening 145 are disposed offset in the radial direction. After the gaseous substances inside the plasma confinement unit 140 enter the annular groove 143 through the inner ring opening 144, the gaseous substances collide with the inner surface of the outer ring wall 142 and are dispersed towards two sides due to no corresponding outer ring opening 145 in the radial direction, and then are discharged through the outer ring openings 145 on two sides, so that the travelling path of the gaseous substances and the probability of collision with the plasma confinement unit 140 are increased, charged particles in residual plasmas in the gaseous substances can be accelerated and annihilated after contacting and colliding with the inner surface of the outer ring wall 142, and in the flowing of the dispersed gaseous substances on two sides, part of the charged particles of the plasmas can collide and reflect between the outer surface of the inner ring wall 141 and the inner surface of the outer ring wall 142, and the energy of the charged particles can be reduced after each collision. It will be appreciated that in another embodiment, the inner ring opening 144 and the outer ring opening 145 are correspondingly disposed in the radial direction, which may compromise the pumping efficiency and reduce the pumping of the plasma to other locations in the reaction chamber.

Further, as shown in fig. 1, in the present embodiment, the lower electrode assembly 110 further includes a shielding ring 114, and the shielding ring 114 is configured to cover at least a portion of the surface of the lower electrode ring 113. The lower electrode ring 113 is mounted and fixed by a mechanical fixing device (such as a bolt assembly, etc.), and the shielding ring 114 is used for protecting the mechanical fixing device from plasma erosion, thereby prolonging the service life thereof. On the other hand, the pumping channel is disposed through the lower surface of the plasma confinement unit 140, that is, the pumping channel is formed by a recess of the lower surface of the plasma confinement unit 140, and the shielding ring 114 is located below the plasma confinement unit 140. In practice, some particulates and/or plasma may be present in the gaseous material exiting the interior of the plasma confinement unit 140, which may have a downward motion during the pumping from the gap, which may promote erosion of the lower electrode ring. In order to alleviate 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 that of the lower electrode ring 113, and the plasma confinement unit 140 is positioned outside the inner diameter of the shielding ring 114 in the radial direction, so that downward movement generated during the process of extracting particles and/or plasma from the gap acts on the shielding ring, reducing the influence on the lower electrode ring 113.

Optionally, the plasma confinement unit 140 is made of a material including one or more of quartz, ceramic, and metal with a dielectric material attached to the surface (e.g., aluminum). Of course, the preparation materials of the plasma confinement unit 140 are not limited to the above, but may be prepared from other materials, which is not limited thereto by the present invention. Further, in order to improve the durability of the plasma confinement unit 140 and ensure the cleanliness in the vacuum reaction chamber 100, the surface of the plasma confinement unit 140 is further provided with a plasma corrosion resistant film layer. Optionally, the plasma corrosion resistant film layer comprises at least one of a teflon film layer, a yttria film layer, or an anodized layer. It will be appreciated that the plasma etch resistant film layer may also comprise other materials, as long as the corresponding functional effect is achieved, as the invention is not limited in this regard.

It should be noted that, the structure of the air extraction channel is not limited to the above scheme, but may be other structures as long as the corresponding functional effects thereof can be achieved, which is not limited by the present invention. As shown in fig. 4 and fig. 5, in another embodiment, the pumping channel is a pumping through hole, that is, the plasma confining unit 240 includes a plurality of grooves 241, each groove 241 forms a pumping through hole, gaseous substances such as process gas, plasma or reaction byproducts pass through the pumping through hole and then are discharged out of the vacuum reaction chamber through the exhaust port, the sidewall of the pumping through hole can reflect charged particles in the plasma for multiple times, each reflection can reduce the energy of the charged particles, accelerate annihilation thereof, annihilate the charged particles in the plasma confining unit 240 as much as possible, and help to protect each component on the pumping path from plasma corrosion, improve the service life of each component, and ensure the cleanliness inside the chamber. In this embodiment, the sidewall of the pumping channel is a planar structure, and in other embodiments, the sidewall of the pumping channel may also be a non-planar structure, such as a wave structure or a zigzag structure, so as to increase the contact area between the plasma and the sidewall of the pumping channel, increase the number of reflections on the plasma, accelerate the annihilation of the plasma, and shorten the radial diffusion free path required by annihilation of the plasma.

Further, the plasma confinement unit 140 is not limited to being connected to the upper electrode ring 124 of the upper electrode assembly 120, and may be provided to be connected to other components of the upper electrode assembly 120. Illustratively, in another embodiment, the plasma confinement unit 140 is mounted on a lower surface of the mounting plate 121 connected to the upper electrode ring 124.

Preferably, as shown in fig. 6 to 8 in combination, a pumping channel is provided to the plasma confinement unit 340, the pumping channel being configured by an inner annular wall 341 provided with an inner annular opening 344 and an outer annular wall 342 provided with an outer annular opening 345, the inner annular wall 341 and the outer annular wall 342 being spaced apart by an annular groove 343. In addition, the plasma confinement unit 340 also includes a baffle structure 346. Specifically, a plurality of baffle structures 346 are disposed in the annular groove 343, the baffle structures 346 are disposed between at least one inner ring opening 344 and an outer ring opening 345, and the inner ring opening 344 and the outer ring opening 345 are disposed correspondingly in the radial direction. In the working state, the gaseous substances entering the annular groove 343 from the inner ring opening 344 collide with the baffle structure 346 first, then diffuse to two sides from the baffle structure 346, and then are discharged out of the plasma confining unit 340 from the outer ring opening 345 respectively, the baffle structure 346 changes to increase the travelling path of the gaseous substances and increase the striking times of charged particles of the plasma in the gaseous substances, so that the plasma is confined in the plasma confining unit 340.

Optionally, the baffle structure 346 is integrally formed with the inner and outer annular walls 341, 342 as at least a portion of the plasma confinement unit 340. The pumping channel formed by the baffle structure 346, the inner annular wall 341 and the outer annular wall 342 may be formed at 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 to the upper electrode assembly 320 and the pumping channel is formed at the lower surface of the plasma confinement unit 340, the baffle structure 346 and the inner and outer annular walls 341 and 342 are formed by recesses on the lower surface of the plasma confinement unit 340. It is understood that the barrier structure 346 is not limited to be formed in the plasma confinement unit 340, but may be directly connected to the lower electrode assembly 310 and interposed between the inner annular wall 341 and the outer annular wall 342. Specifically, as shown in fig. 8, the baffle structure 346 is connected to the shadow ring 314 of the lower electrode assembly 310, and the inner and outer annular walls 341 and 342 of the plasma confinement unit 340 are connected to the upper electrode assembly 320. During transfer of the substrate W, the distance between the upper electrode assembly 320 and the lower electrode assembly 310 is adjusted by moving the two such that the substrate W is placed on the susceptor 311 through between the bottoms of the inner and outer annular walls 341 and 342 and the top of the barrier structure 346. After the transfer is completed, the upper electrode assembly 320 or the lower electrode assembly 310 is adjusted to reduce the distance between the upper electrode assembly and the lower electrode assembly, and in the process, the baffle structure 346 is inserted into the annular groove 343, so that the plasma is impacted in the plasma restraint unit 340 for multiple times in the process of etching the edge of the substrate W, the energy of charged particles is reduced, and the damage of the plasma to all parts on the pumping path is avoided. The size of the openings on the inner annular wall 341 and the outer annular wall 342 of the plasma confinement unit 340 and the size of the baffle plate structure 346 can be adjusted to meet the requirement of adjusting the uniformity of vacuum pumping, and meanwhile, the limiting capacity of the baffle plate structure on the plasma can be increased, so that the cooperative optimal adjustment of all process conditions is realized, and the better wafer processing effect is ensured.

Optionally, the barrier structure 346 near the region of the exhaust port 304 has a larger barrier area than the barrier structure 346 far from the region of the exhaust port 304, i.e., the exhaust resistance of the region near the exhaust port 304 is greater than the region far from the exhaust port 304, to ensure uniformity in the circumferential direction of the edge of the substrate W while balancing vacuum exhaust and plasma confinement capabilities. Wherein the blocking area of the baffle structure 346 may be adjusted by adjusting the depth of insertion of the baffle structure 346 into the annular groove 343 or by other means, as the invention is not limited in this respect. Further alternatively, the size of the openings (344, 345) in each circumferential direction of the substrate W may be adjusted as desired to meet actual process requirements. Illustratively, the openings (344, 345) near the exhaust port 304 are smaller than the openings (344, 345) far from the exhaust port 304. In some embodiments, the magnitude of the pumping resistance can also be controlled by how many pumping channels are provided, the size of the pumping channels, or the length of the pumping channels.

In some embodiments, the plasma confinement unit may be further connected to the lower electrode assembly. The air exhaust channel is arranged on the plasma confinement unit, and a gap exists between the plasma confinement unit and the upper electrode assembly in the process, and an air exhaust inlet of the air exhaust channel is lower than the plane of the substrate in the vertical direction. The air extraction channel may be formed in the same manner as in the previous embodiments.

In summary, in the plasma edge etching apparatus of the present invention, the plasma around the substrate W is limited by the plasma confining unit 140, so that the plasma is uniformly distributed around the substrate, and the cleaning effect is improved; in addition, the device is also provided with an air extraction channel to control air extraction, meanwhile, the probability of extinguishing plasma in the air extraction channel is increased through the design of the air extraction channel, the leakage of the plasma to a non-reaction area is reduced, and the damage to parts in the non-reaction area is avoided.

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 construed as limiting the invention, and that the embodiments of the present invention and the technical features of the embodiments can be combined with each other without conflict, and the combined technical solutions should also be regarded as technical solutions described in the present invention. Many modifications and substitutions of the present invention will become apparent to those of ordinary skill in the art upon reading the foregoing. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims (18)

1. A plasma edge etching apparatus, comprising:

A vacuum reaction chamber, wherein a movable upper electrode assembly or a lower electrode assembly is arranged in the vacuum reaction chamber, the lower electrode assembly is used for supporting a substrate, the upper electrode assembly comprises an upper electrode ring, the lower electrode assembly comprises a lower electrode ring, and the upper electrode ring and the lower electrode ring are oppositely arranged;

the plasma restraint unit is arranged at the periphery of the substrate and used for restraining plasma formed around the substrate; and an air exhaust channel communicated with the inner side and the outer side of the plasma confinement unit.

2. The plasma edge etching apparatus of claim 1, wherein,

The pumping channel is formed at a lower surface, an upper surface or a portion between the upper and lower surfaces of the plasma confinement unit.

3. The plasma edge etching apparatus of claim 2, wherein,

The vacuum reaction chamber is unevenly provided with an exhaust port, and the air extraction capacity of the air extraction channel of the area close to the exhaust port is smaller than the air extraction capacity of the air extraction channel of the area far away from the exhaust port.

4. The plasma edge etching apparatus of claim 1, wherein,

The plasma confinement unit is arranged on the lower surface of the upper electrode ring or the radial outer side of the upper electrode ring, and the air suction 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 air suction inlet of the air suction channel is higher than the plane of the substrate in the vertical direction.

5. The plasma edge etching apparatus of claim 4, wherein,

At least part of the plasma restraint unit consists of an inner annular wall and an outer annular wall, and the air 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 formed in the inner annular wall, and an outer ring opening is formed in the outer annular wall.

6. The plasma edge etching apparatus of claim 5, wherein,

The inner ring openings and the outer ring openings are uniformly distributed in the circumferential direction.

7. The plasma edge etching apparatus of claim 6, wherein,

The inner ring opening and the outer ring opening are arranged in a staggered manner in the radial direction.

8. The plasma edge etching apparatus of claim 5, wherein,

The inner ring opening and the outer ring opening are correspondingly arranged in the radial direction, 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.

9. The plasma edge etching apparatus of claim 8, wherein,

The baffle structure is fixedly connected with the lower electrode assembly.

10. The plasma edge etching apparatus of claim 8, wherein,

The vacuum reaction chamber is unevenly provided with an exhaust port, and the resistance of the baffle structure in the area close to the exhaust port to air suction is greater than that in the area far away from the exhaust port.

11. The plasma edge etching apparatus of claim 1, wherein,

The lower electrode assembly further includes a shielding ring for covering at least a portion of a surface of the lower electrode ring.

12. The plasma edge etching apparatus of claim 11, wherein,

The plasma confinement unit is integrally arranged with the shielding ring.

13. The plasma edge etching apparatus of claim 11, wherein,

And a gap exists between the plasma confining unit and the upper electrode assembly, the air exhaust channel is formed on the plasma confining unit, and an air exhaust inlet of the air exhaust channel is lower than the plane of the substrate in the vertical direction during the process.

14. 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 that of the lower electrode ring, and the plasma restraining unit is located outside the inner diameter of the shielding ring in the radial direction.

15. The plasma edge etching apparatus of claim 1, wherein,

The air exhaust channel is an air exhaust through hole, a wave structure or a fold line structure.

16. The plasma edge etching apparatus of claim 1, wherein,

The upper electrode assembly comprises a mounting plate connected with the upper electrode ring, and the plasma confinement unit is mounted on the lower surface of the mounting plate.

17. The plasma edge etching apparatus of claim 1, wherein,

The preparation material of the plasma confinement unit comprises one or more of quartz, ceramic and metal with dielectric materials attached to the surface.

18. 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 oxidation layer.