A double-layer plasma grid and a plasma processing apparatus

Abstract

The application relates to the technical field of wafer processing equipment, in particular to a double-layer plasma grid and a plasma processing equipment, which comprises a first layer grid and a second layer grid, a plurality of first axial holes corresponding to the center area and the edge area of a wafer are arranged on the first layer grid in the axial direction; the second layer grid is rotatably arranged in the first window and is attached to the bottom of the first layer grid, a plurality of gas guide structures are arranged on the second layer grid in the circumferential direction, the gas guide structures comprise a center gas guide hole with an air outlet end facing the center area of the wafer and an edge gas guide hole with an air outlet end facing the edge area of the wafer, the diameters of the center gas guide hole, the edge gas guide hole and the first axial hole are matched; the application can flexibly switch the delivery proportion of the plasma to the center area and the edge area of the wafer by rotating the second layer grid relative to the first layer grid, the requirement under different processes can be met without replacing the grid body, and the problems of poor adaptability and high replacement cost of the existing single fixed grid are solved.

Description

Technical Field

[0001] This invention relates to the field of wafer processing equipment technology, and more particularly to a double-layer plasma grid and plasma processing equipment. Background Technology

[0002] In plasma processes such as resist stripping and etching in wafer manufacturing, the plasma grid is the core hardware for controlling the distribution of process gases and the concentration of active particles. The distribution of its uniform orifices directly determines the uniformity of the process rate on the wafer surface. Current industry standard solutions use a single grid with a fixed orifice distribution, which can only fine-tune uniformity by adjusting parameters such as process pressure and gas ratio, resulting in extremely poor adaptability. For example, for process scenarios where the resist stripping rate is relatively fast in the center, a uniform orifice layout with "dense on the outside and sparse on the inside" is required to reduce the particle concentration in the central area; if switching to a process with a faster rate at the edge, a grid with "sparse on the outside and dense on the inside" needs to be replaced. This not only results in high replacement costs and long downtime, but also fails to cover the ever-changing process requirements. Summary of the Invention

[0003] This invention relates to a double-layer plasma grid and plasma processing equipment. The purpose is to flexibly switch the plasma delivery ratio to the center and edge regions of the wafer by rotating the second grid relative to the first grid. This allows for adaptation to different process requirements without replacing the grid body, solving the problems of poor adaptability and high replacement costs of existing single fixed grids.

[0004] To achieve the above objectives, the present invention provides a double-layer plasma grid, comprising: The first layer of grid is fixed in the first window that runs through the axial direction of the fixed base. The first layer of grid has a number of first axial holes that respectively correspond to the central region and the edge region of the wafer. The second layer of grid is rotatably installed inside the first window and attached to the bottom of the first layer of grid. The second layer of grid has a plurality of gas guiding structures along its circumferential direction. The plurality of gas guiding structures can be arranged to form one or more concentric annular structures with different radii. The gas guiding structure includes a central gas guiding hole with the gas outlet facing the center region of the wafer and an edge gas guiding hole with the gas outlet facing the edge region of the wafer. The diameters of the central gas guiding hole, the edge gas guiding hole and the first axial hole are matched. When the central gas guiding hole and the edge gas guiding hole are aligned and connected with the first axial hole, a first flow channel and a second flow channel are formed. The second layer of the grid is rotated circumferentially to connect the first or second flow channel, thereby adjusting the ratio of plasma flux entering the central region to the edge region.

[0005] Optionally, the air guiding structure further includes a second axial hole that matches the diameter of the first axial hole and extends along the axial direction; the first layer of grid has a plurality of arc segments that correspond one-to-one with the air guiding structure, and a first axial hole is provided for each arc segment of the air guiding structure. When the second axial hole is aligned and connected with the first axial hole, a third flow channel is formed; the circumferential rotation of the second layer of grid makes any one of the first flow channel, the second flow channel and the third flow channel connected.

[0006] Optionally, the air guiding structure further includes a first sub-axial hole and a second sub-axial hole that match the diameter of the first axial hole and are axially connected, and the central air guiding hole, the first sub-axial hole, the edge air guiding hole and the second sub-axial hole in the same air guiding structure are arranged sequentially in the circumferential direction; the first layer of grid is provided with a number of arc-shaped segments, and each arc-shaped segment of the air guiding structure is provided with two first axial holes. When the first sub-axial hole and the second sub-axial hole are aligned and connected with the first axial hole, they form the fourth and fifth flow channels, respectively. The circumferential rotation of the second layer of the grid connects the fourth flow channel and the first flow channel, or connects the fourth flow channel and the second flow channel, or connects the second flow channel and the fifth flow channel.

[0007] Optionally, the second layer of the grid includes an inner ring region corresponding to the center region of the wafer and an outer ring region corresponding to the edge region of the wafer; Both the inner and outer ring regions are provided with the air guiding structure, and the number of the first, second, fourth, and fifth flow guiding channels in the inner and outer ring regions is the same.

[0008] Optionally, the central air guide hole includes: The first axial section is disposed along the axial direction in the second layer of the grid; The first inclined section is located at the bottom of the first axial section and communicates with the first axial section; the extension structure of the gas outlet end of the first inclined section extends toward the central region of the wafer.

[0009] Optionally, the edge air vent includes: The second axial section is disposed along the axial direction in the second layer of the grid. The second inclined section is located at the bottom of the second axial section and communicates with the second axial section; the extension structure of the gas outlet end of the second inclined section extends toward the edge region of the wafer.

[0010] Optionally, the double-layer plasma grid further includes a flow regulating element; Each of the central air guide holes and each of the edge air guide holes is provided with a flow regulating component; The flow regulating component includes a blocking part, at least a portion of which extends from the outlet end of the first inclined section or the outlet end of the second inclined section into the first inclined section or the second inclined section, so that the circumferential outer wall of the blocking part forms a flow passage with the circumferential inner wall of the first inclined section or the second inclined section, and the blocking area of ​​the blocking part decreases toward the inlet end of the central air guide hole or the inlet end of the edge air guide hole. The plasma flux ratio between the central region and the edge region can be adjusted by controlling the movement of the blocking part toward or away from the air inlet end of the central air guide or the air inlet end of the edge air guide.

[0011] Optionally, the flow regulating component further includes a driving part, which is disposed on the second layer of the grid, and its driving end extends along the axial direction of the first inclined section or the second inclined section and is connected to the blocking part, so as to adjust the amount of the blocking part extending into the first inclined section or the second inclined section by controlling the movement of the blocking part toward or away from the air inlet end of the central air guide hole or the air inlet end of the edge air guide hole.

[0012] Optionally, the opposing sidewalls of the first window and the second layer of the grid form a first mating portion and a second mating portion; The first docking portion has a support groove that extends circumferentially. A rotating component is fixed on the second docking part. The rotating component is movably disposed in the support groove, and a first driving component is provided at its end located in the support groove. Several second driving components are provided at circumferential intervals in each area of ​​the inner sidewall of the support groove. The first driving component and several second driving components are respectively connected to an independent power supply. By controlling the power on and off of each second driving component, the first driving component is attracted and driven to carry the second layer of grid mesh to make circumferential rotational movement.

[0013] Optionally, the double-layer plasma grid also includes at least one angle positioning sensor; At least one of the angle positioning sensors is disposed on the inner sidewall of the support groove. The angle positioning sensor is used to detect the real-time rotation angle of the first driving member and feed the angle signal back to the control module of the peripheral device to realize the control of the rotational motion of the second layer of grid.

[0014] Optionally, a third driving component is also included. The third driving component is disposed on the inner sidewall of the first window, and its driving end is connected to the second layer of the grid. The third driving component drives the second layer of the grid to move up and down along the axial direction to adjust the spacing between the second layer of the grid and the first layer of the grid.

[0015] Optionally, a wear-resistant bonding layer is provided on the side of the second layer grid facing the first layer grid, and the surface roughness of the wear-resistant bonding layer is less than or equal to 0.8 μm, so as to reduce the frictional loss between the second layer grid and the first layer grid during the rotation of the second layer grid.

[0016] To achieve the above objectives, the present invention also provides a plasma processing apparatus, including a processing chamber, a dielectric window, a fixed base and a stage, and the aforementioned double-layer plasma grid. The fixed base is disposed between the processing chamber and the dielectric window. The top of the processing chamber is provided with a second window adapted to and communicating with the first window in the fixed base. The stage is disposed in the processing chamber, and its top is used to support a wafer.

[0017] The beneficial effects of this invention are as follows: This invention addresses the pain points of existing plasma grids with a single fixed hole distribution, which require replacement to adapt to different process rate deviations in the central and edge regions of wafers, resulting in high replacement costs and long downtime. By fixing first axial holes corresponding to the central and edge regions of the wafer in the first layer of the grid, and cooperating with the central vent and edge vent on the circumferentially rotatable second layer of the grid, the conduction state of the first and second flow channels can be switched simply by controlling the rotation angle of the second layer of the grid. This allows for flexible adjustment of the plasma flux ratio between the central and edge regions, adapting to various process scenarios where the central region has a faster resist removal or etching rate, or the edge region has a faster rate, without downtime for replacement. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a semiconductor processing device in some embodiments of the present invention; Figure 2 for Figure 1 The diagram shows a structure with air distribution holes on the second layer of the grid. Figure 3 for Figure 2 Schematic diagrams of the three configurations of uniform air pores shown; Figure 4 for Figure 1 A magnified schematic diagram of structure A shown in the figure.

[0019] Explanation of reference numerals in the attached figures 1. Processing chamber; 2. Medium window; 3. Fixed base; 301. First window; 4. Grid body; 41. First layer of grid; 411. First axial hole; 42. Second layer of grid; 421. Central air guide hole; 422. First sub-axial hole; 423. Edge air guide hole; 424. Second sub-axial hole; 5. Support groove; 6. Rotating component; 7. First driving component; 8. Second driving component. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0021] This invention relates to a double-layer plasma grid and plasma processing equipment. The purpose is to flexibly switch the plasma delivery ratio to the center and edge regions of the wafer by rotating the second grid relative to the first grid. This allows for adaptation to different process requirements without replacing the grid body, solving the problems of poor adaptability and high replacement costs of existing single fixed grids.

[0022] To address the problems existing in the prior art, embodiments of the present invention provide a double-layer plasma grid, such as... Figure 1 As shown, the double-layer plasma grid includes a first-layer grid 41 and a second-layer grid 42.

[0023] In some embodiments, such as Figure 1 As shown, the first layer of grid 41 is fixed in the first window 301 that runs through the fixed base 3 along the axial direction. The first layer of grid 41 is provided with a plurality of first axial holes 411 that correspond to the central region and the edge region of the wafer respectively.

[0024] In some embodiments, such as Figure 1 and Figure 2As shown, the second-layer grid 42 is rotatably installed within the first window 301 and fitted to the bottom of the first-layer grid 41. The second-layer grid 42 has several gas guiding structures along its circumference. Each gas guiding structure includes a central gas guiding hole 421 with its outlet facing the center region of the wafer and an edge gas guiding hole 423 with its outlet facing the edge region of the wafer. The diameters of the central gas guiding hole 421, the edge gas guiding hole 423, and the first axial hole 411 are matched (i.e., the diameters of the central gas guiding hole 421, the edge gas guiding hole 423, and the first axial hole 411 are the same, the number of holes is the same, the spacing between adjacent holes is the same, and the opening direction is also the same). When the central gas guiding hole 421 and the edge gas guiding hole 423 are aligned and connected with the first axial hole 411, they form a first flow channel and a second flow channel. The second-layer grid 42 can be rotated circumferentially to connect either the first or second flow channel, thereby adjusting the ratio of plasma flux entering the center region to that entering the edge region.

[0025] This embodiment can quickly switch between the first and second flow channels connecting the corresponding central and edge regions by controlling the circumferential rotation of the second-layer grid 42. It can flexibly adjust the plasma flux ratio between the central and edge regions of the wafer without stopping the machine to replace the grid. It can adapt to various operating conditions where the process rate is faster in the central region or faster in the edge region, greatly reducing downtime caused by component replacement, reducing maintenance costs, and accurately controlling the plasma distribution to effectively improve the uniformity of the wafer surface process.

[0026] In some embodiments, a plurality of the air-guiding structures form a ring-shaped structure along the circumference, and one or more concentric ring-shaped structures with different radii may be formed on the second layer of the grid 42. It is worth noting that the first axial hole 411 on the first layer of the grid 41 is adapted to form one or more concentric ring-shaped structures with different radii by the air-guiding structures on the second layer of the grid 42. It can be understood that the number of ring-shaped structures formed by the first layer of the grid 41 and the second layer of the grid 42 is the same, and their positions correspond.

[0027] In some embodiments, the diameters of the central air guide hole 421, the edge air guide hole 423, and the first axial hole 411 are preferably set to be the same, and all three adopt an equal diameter design. This ensures the consistency of the flow cross section, avoids eddies caused by abrupt changes in aperture, ensures stable plasma flux transmission, and reduces particle scattering losses. On the other hand, the equal diameter matching allows the first or second flow guide channel to maximize flux and flow without obstruction in the fully open state, while simplifying the manufacturing process.

[0028] In some embodiments, the air guiding structure further includes a second axial hole that matches the diameter of the first axial hole 411 and extends through it axially; the first layer of grid 41 is provided with a plurality of arc segments that correspond one-to-one with the air guiding structure, and a first axial hole is provided for each arc segment of the air guiding structure; when the second axial hole is aligned and connected with the first axial hole 411, a third flow channel is formed, and the second layer of grid 42 is rotated circumferentially to connect the first flow channel, the second flow channel, or the third flow channel.

[0029] This embodiment adds a fully conductive third flow channel mode to the original "supply gas to the center only" and "supply gas to the edge only" modes, allowing the grid body 4 to adapt to more process scenarios. For example, when conventional processes require uniform gas supply to the entire wafer, the second-layer grid 42 is rotated to align the second axial hole with the first axial hole 411. At this time, the central gas guide hole 421 and the edge gas guide hole 423 in the gas guide structure will not form a first flow channel and a second flow channel with the first axial hole 411 in the arc segment. The gas flows through the first flow channel. The plasma paths to the central and edge regions are not connected via the second flow channel, allowing plasma to be uniformly delivered to the entire wafer without requiring additional parameter adjustments. If a special process occurs where the resist removal rate in the central region is too fast, simply rotate the second-layer gate 42 to switch to a central-region-only gas supply mode (activating the first flow channel), eliminating the need for machine downtime and component replacement. Similarly, if a special process occurs where the etching rate in the edge region is too fast, rotate the second-layer gate 42 to switch to an edge-region-only gas supply mode (activating the second flow channel), again eliminating the need for machine downtime and component replacement. These three modes can be switched as needed, expanding the equipment's process compatibility and avoiding the cumbersome process of repeatedly disassembling and reassembling the gate body 4 for different process requirements, further improving production efficiency and the flexibility of process control.

[0030] In some embodiments, such as Figure 2 and Figure 3 As shown, the air guiding structure further includes a first sub-axial hole 422 and a second sub-axial hole 424 that match the diameter of the first axial hole 411 and extend axially. The central air guiding hole 421, the first sub-axial hole 422, the edge air guiding hole 423, and the second sub-axial hole 424 in the same air guiding structure are arranged sequentially along the circumference. The first layer of the grid 41 has several arc-shaped segments corresponding one-to-one with the air guiding structure, and each arc-shaped segment of the air guiding structure has two first axial holes 411.

[0031] In some embodiments, the diameters of the first sub-axial hole 422 and the second sub-axial hole 424 are preferably the same as those of the first axial hole 411.

[0032] In some embodiments, such as Figure 3As shown, when the first sub-axial hole 422 and the second sub-axial hole 424 are aligned and connected with the first axial hole 411, they form the fourth flow channel and the fifth flow channel, respectively. The second layer of grid 42 connects the fourth flow channel and the first flow channel, or connects the fourth flow channel and the second flow channel, or connects the second flow channel and the fifth flow channel by circumferential rotation.

[0033] In this embodiment, the first flow channel is considered to be in a constantly active state. Regardless of how the second-layer grid 42 rotates, the central and edge regions always maintain a basic plasma supply, fundamentally avoiding the risk of process anomalies caused by a complete gas cut-off in a single region. Based on this, other flow channels can be flexibly superimposed according to actual process deviations: if the etching or resist removal rate in the wafer edge region is too slow, the second-layer grid 42 can be rotated to simultaneously conduct the second and fourth flow channels or the second and fifth flow channels, providing additional plasma flux to the edge region and reducing the rate difference between the central and edge regions; if the central rate is too slow, the first and fourth flow channels or the first and fifth flow channels can be switched to conduct in combination, directionally increasing the supply ratio in the central region. Under the premise of ensuring a basic flux, continuous fine-tuning of the flux ratio between the central and edge regions is achieved, which not only ensures the safety of the process, but also upgrades the control precision from "on or off switching" to "gradient increase or decrease", perfectly adapting to the fine control requirements for wafer in-plane uniformity under different process nodes.

[0034] In some embodiments, the second layer of the grid 42 includes an inner ring region corresponding to the center region of the wafer and an outer ring region corresponding to the edge region of the wafer; both the inner ring region and the outer ring region are provided with the gas guiding structure, and the number of the first flow channel, the second flow channel, the fourth flow channel and the fifth flow channel in the inner ring region and the outer ring region are the same.

[0035] The second-layer grid 42 is divided into inner and outer ring regions according to the wafer's functional areas, with independently arranged gas guiding structures. The number of various flow channels in both regions is consistent, achieving independent and symmetrical gas supply to the central and edge regions while ensuring uniformity of aperture density per unit area. The gas guiding structure in the inner ring region specifically regulates the plasma supply to the wafer's central region, while the gas guiding structure in the outer ring region precisely matches the needs of the wafer's edge regions, avoiding uneven gas supply in a single region. Simultaneously, the equal number of multi-channel designs ensures completely equal control amplitudes for the inner and outer ring regions. For example, if a 20% increase in flux in the central region is required, simply rotating the second-layer grid 42 aligns the first flow channel on the outer ring region with the central region. The same applies to the inner ring, eliminating the need for additional calibration of flow deviations between the two regions and reducing control complexity. It is important to note that the guiding plasma movement direction of the central gas guide hole 421 and the edge gas guide hole 423 in both the inner and outer ring regions is consistent.

[0036] In one embodiment, the positions of the central air guide holes 421 and the edge air guide holes 423 on different air guide structures within the same annular structure are arranged differently. For example, three air guide structures are provided in the annular structure: the first air guide structure has four central air guide holes 421, the second air guide structure has four edge air guide holes 423, and the third air guide structure has two first sub-axial holes 422 and two second sub-axial holes 424. Furthermore, these three air guide structures can be arranged in any possible manner within the annular structure, which will not be elaborated further here.

[0037] In this embodiment, the three gas-conducting structures correspond to different flux supply modes. The first gas-conducting structure concentrates the plasma supply to the central region, which is suitable for scenarios where the wafer center rate is low and efficiency needs to be improved; the second gas-conducting structure only transports plasma to the edge region, which can separately correct edge etching or deposition deviations when the center process uniformity meets the standard; the third gas-conducting structure covers the flux supply to both the center and the edge at the same time, which is used to balance the reaction rate across the entire region.

[0038] Preferably, the number of air-guiding structures provided on the inner ring region and the outer ring region is the same.

[0039] In some embodiments, such as Figure 3 As shown, the central vent 421 includes a first axial section and a first inclined section: the first axial section is disposed along the axial direction on the second layer grid 42; the first inclined section is disposed at the bottom of the first axial section and communicates with the first axial section; the extension structure of the vent end of the first inclined section extends toward the central region of the wafer.

[0040] This embodiment utilizes the guiding effect of the first inclined section to actively deflect and converge the plasma gas flow that was originally falling vertically towards the center region of the wafer, avoiding the waste of flux caused by the gas flow diverging to non-target areas. Compared with the straight hole structure, the directional guidance of the first inclined section can effectively increase the plasma volume in the center region and reduce the ineffective gas supply in the edge region. Especially in large-size wafer processes, it can significantly reduce the gas flow attenuation rate from the center region to the edge region. Combined with the rotation adjustment of the second layer of the grid 42, it can more accurately match the plasma requirements of the center region under different processes.

[0041] In some embodiments, the tilt angle of the first tilting segment can be flexibly set according to the wafer size and process requirements. For example, the angle formed by the axial extension structure of the first tilting segment intersecting one of the axes of the processing chamber 1 can be selected as 10°-45°. A small tilt angle (e.g., a tilt angle of 10°-25°) can minimize flow resistance while ensuring that the plasma is deflected towards the center, which is suitable for scenarios where the flux in the central region is finely adjusted. A large tilt angle (e.g., a tilt angle of 25°-45°) can significantly enhance the convergence effect of the airflow, which is suitable for processes where the central resist removal or etching rate is significantly slow and a significant increase in the plasma concentration in the central region is required. By matching the first tilting segment with different tilt angles, the deflection amplitude of the plasma towards the central region can be precisely controlled without changing the overall structure of the gate body 4, further optimizing the flux distribution ratio between the central and edge regions of the wafer.

[0042] In some embodiments, such as Figure 3 As shown, the edge vent 423 includes a second axial section and a second inclined section: the second axial section is disposed along the axial direction on the second layer grid 42; the second inclined section is disposed at the bottom of the second axial section and communicates with the second axial section; the extension structure of the vent end of the second inclined section extends toward the edge region of the wafer.

[0043] This embodiment utilizes the directional flow guidance effect of the second inclined section to actively deflect and converge the originally vertically falling plasma gas flow towards the wafer edge region, effectively avoiding flux loss caused by the gas flow diverging towards the non-target area in the center. Compared with the traditional straight hole structure, this design can significantly improve the plasma landing accuracy in the edge region. Especially in large-size wafer processes, it can compensate for the particle concentration attenuation problem caused by diffusion and sheath effect in the edge region. Combined with the rotation adjustment of the second layer grid 42, it can more accurately match special process requirements such as slower edge resist removal or etching rate. It complements the inclined design of the central vent 421, and together achieves bidirectional precise control of flux distribution in the wafer center and edge regions, further reducing the process rate deviation on the wafer surface and improving the processing uniformity of the entire wafer.

[0044] In some embodiments, the tilt angle of the second tilting segment can be flexibly adjusted according to the wafer size and edge process requirements. For example, the angle formed by the axial extension structure of the second tilting segment intersecting with one of the axes of the processing chamber 1 can be 10°~60°. A small tilt angle (e.g., 10°~25°) is more suitable for scenarios where the flux in the edge region is slightly and precisely reinforced, which can ensure smooth airflow while avoiding excessive outward expansion of the airflow. A large tilt angle (25°~60°) can significantly enhance the deflection and convergence effect of the airflow towards the edge, which is especially suitable for the condition of uneven edge sheath thickness and easy dissipation of particles towards the center in 12-inch and larger wafer processes, and can effectively compensate for the plasma concentration decay in the edge region. By matching the second tilt segment with different tilt angles, the proportion of plasma flowing to the edge region can be precisely controlled without changing the structure of the gate body 4. This, combined with the tilt angle of the central vent 421, forms a combined adjustment effect. This not only avoids uneven etching or resist removal rates in the edge region due to excessive airflow scouring, but also fills the gas supply blind spots in the edge region that are difficult to cover by traditional straight hole structures, further improving the control accuracy and process adaptability of flux distribution within the wafer surface.

[0045] In some embodiments, the double-layer plasma grid further includes a flow regulator; each of the central air guide holes 421 and each of the edge air guide holes 423 is provided with a corresponding flow regulator; the flow regulator includes a blocking portion, at least a portion of which extends from the outlet end of the first inclined section or the outlet end of the second inclined section into the first inclined section or the second inclined section, so that the circumferential outer wall of the blocking portion forms a flow channel with the circumferential inner wall of the first inclined section or the second inclined section, and the blocking area of ​​the blocking portion decreases toward the inlet end of the central air guide hole 421 or the inlet end of the edge air guide hole 423, so that the plasma flux ratio of the central region and the edge region can be adjusted by controlling the movement of the blocking portion toward or away from the inlet end of the central air guide hole 421 or the inlet end of the edge air guide hole 423.

[0046] By independently configuring flow regulators with tapered blocking sections in each central vent 421 and edge vent 423, the plasma flux in the central and edge regions of the wafer can be controlled without replacing the grid. The tapered blocking area design makes the depth of the blocking section into the cavity linearly correspond to the cross-sectional area of ​​the flow channel. Only a slight adjustment of the axial displacement of the blocking section along the central vent 421 or edge vent 423 is needed to precisely control the particle flux ratio in different regions.

[0047] In some embodiments, the structure of the blocking part can be a cone, a frustum, or a multi-stage stepped shaft structure. The cone or frustum structure can form a continuously and gradually changing annular flow channel with the inner walls of the first and second inclined sections. As the insertion amount increases, the flow cross section smoothly shrinks, making it less prone to sudden airflow changes. The multi-stage stepped shaft structure can achieve segmented flow regulation through stepped surfaces of different diameters, adapting to different precision control requirements.

[0048] In some embodiments, the flow regulating component further includes a driving unit disposed on the second layer of the grid 42, with its driving end extending axially along the first inclined segment or the second inclined segment and connected to the blocking part. This allows adjustment of the insertion amount of the blocking part into the first inclined segment or the second inclined segment by controlling the movement of the blocking part toward or away from the air inlet end of the central air guide or the air inlet end of the edge air guide, thereby adjusting the plasma flux ratio between the central region and the edge region. In this embodiment, the driving unit is integrated into the second layer of the grid 42, eliminating the need for an external linkage transmission structure. This avoids the risk of pipeline entanglement during operation and ensures that the driving end of each driving unit is coaxially connected to the corresponding blocking part, preventing the adjustment accuracy from being affected by the circumferential rotation of the grid body. In specific embodiments, the driving unit may be, but is not limited to, a miniature cylinder.

[0049] In some embodiments, such as Figure 4 As shown, the opposing sidewalls of the first window 301 and the second layer of the grid 42 form a first docking portion and a second docking portion; a support groove 5 extending circumferentially is recessed on the first docking portion; a rotating member 6 is fixed on the second docking portion, the rotating member 6 is movably disposed in the support groove 5, and a first driving member 7 is provided at its end located in the support groove 5; a plurality of second driving members 8 are provided circumferentially at intervals in each region of the inner sidewall of the support groove 5; the first driving member 7 and the plurality of second driving members 8 are respectively connected to an independent power supply, and the first driving member 7 is attracted and driven to rotate the second layer of the grid 42 circumferentially by controlling the power on and off of each second driving member 8 respectively.

[0050] The first docking part's support groove 5 and the second docking part's rotating component 6 form an embedded rotational engagement, providing stable circumferential support for the second-layer grid 42. Multiple second driving components 8, circumferentially spaced on the inner wall of the support groove 5, work in conjunction with the first driving component 7 at the end of the rotating component 6 to construct a "stator-moving" electromagnetic drive structure. This eliminates the need for additional gears, belts, or other mechanical transmission components, fundamentally avoiding particulate contamination caused by mechanical wear, thus meeting the ultra-cleanliness requirements of wafer processing. Simultaneously, the independent on / off control logic of each second driving component 8 enables precise step-by-step positioning of the first driving component 7, with high rotation angle resolution. The driving force acts directly on the rotating component 6, resulting in fast response and smooth start-stop, allowing stable operation even in vacuum environments. Combined with subsequent sensor feedback, it can precisely control the rotation angle of the second-layer grid 42, ensuring the alignment accuracy of the flow channel and further improving the reliability and process repeatability of plasma flux regulation.

[0051] In some specific embodiments, a support groove 5 is provided on the first window 301; a rotating component 6 is provided on the second layer of grid 42.

[0052] In some embodiments, the double-layer plasma grid further includes at least one angle positioning sensor; at least one angle positioning sensor is disposed on the inner sidewall of the support groove 5, and the angle positioning sensor is used to detect the real-time rotation angle of the first drive member 7 and feed the angle signal back to the control module of the peripheral device to realize the control of the rotational motion of the second layer grid 42.

[0053] By capturing the rotation angle of the first driving component 7 in real time using an angle positioning sensor, it is equivalent to equipping the rotation of the second layer of grid 42 with a "high-precision ruler": on the one hand, it can control the alignment accuracy of the flow channel within ±0.1°, ensuring that the central air guide hole 421, the edge air guide hole 423, the second axial hole and the first axial hole 411 are completely aligned, avoiding the reduction of the flow cross section, the deflection of airflow and even the loss of plasma scattering caused by the offset of the hole position; on the other hand, the angle positioning sensor feeds back the real-time angle to the control module of the peripheral device to form a closed-loop control, which can automatically correct the stepping error caused by the power-on and power-off of the second driving component 8.

[0054] In some embodiments, the double-layer plasma grid further includes a third driving member, which is disposed on the inner sidewall of the first window 301 and its driving end is connected to the second layer grid 42. The third driving member drives the second layer grid 42 to move up and down along the axial direction to adjust the spacing between the second layer grid 42 and the first layer grid 41.

[0055] In this embodiment, the third driving component drives the second layer of grid 42 to move up and down slightly along the axial direction, which can flexibly adjust the fitting gap between the two layers of grid: when the gap is small, the sealing of the orifice conduction is better, plasma leakage is less, and flux control is more precise, which is suitable for fine processes with high flow accuracy requirements; when the gap is large, the friction loss between the two layers of grid can be reduced, while reserving thermal expansion buffer space to avoid grid deformation and jamming under high temperature processes. More importantly, the change in axial spacing will directly affect the effective conduction length of the guide channel, thereby fine-tuning the plasma diffusion angle and landing point distribution.

[0056] In some embodiments, a wear-resistant bonding layer is provided on the side of the second layer grid 42 facing the first layer grid 41. The surface roughness Ra of the wear-resistant bonding layer is less than or equal to 0.8 μm to reduce frictional loss between the second layer grid 42 and the first layer grid 41 during the rotation of the second layer grid 42. The high-gloss wear-resistant bonding layer can significantly reduce the frictional resistance when the two layers of grids rotate relative to each other, reduce the generation of wear particles, avoid contamination of the process chamber, and maintain the sealing of the bonding surface to prevent plasma leakage from the gap and ensure the flow rate accuracy of the guide channel.

[0057] To address the problems existing in the prior art, embodiments of the present invention also provide a plasma processing device, including a processing chamber 1, a dielectric window 2, a fixed base 3, and a stage, as well as the aforementioned double-layer plasma grid. The fixed base 3 is disposed between the processing chamber 1 and the dielectric window 2. The top of the processing chamber 1 is provided with a second window adapted to and communicating with the first window 301 in the fixed base 3. The stage is disposed in the processing chamber 1, and its top is used to support a wafer.

[0058] In some embodiments, the plasma processing equipment includes an etching device, a resist stripping device, and a deposition device, all of which can be adapted to the dual-layer plasma grid described in this invention: In the etching process, the uniformity of the etching rate in the central and edge regions can be precisely controlled by adjusting the plasma flux ratio between the central and edge regions, avoiding over-etching in the central region or residue in the edge region; In the resist stripping process, the problem of slow resist stripping rate in the edge region can be specifically compensated, improving the photoresist removal efficiency of the entire wafer; In the deposition process, the plasma distribution of the reactive gas can be optimized to ensure the in-plane consistency of the film thickness.

[0059] Although embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the present invention. Furthermore, the present invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A double-layer plasma grid, characterized in that, include: The first layer of grid is fixed in the first window that runs through the axial direction of the fixed base. The first layer of grid has a number of first axial holes that respectively correspond to the central region and the edge region of the wafer. The second layer of the grid is rotatably installed inside the first window and attached to the bottom of the first layer of the grid. The second layer of the grid has a plurality of gas guiding structures along its circumferential direction. The plurality of gas guiding structures form one or more concentric annular structures with different radii. The gas guiding structure includes a central gas guiding hole with the gas outlet facing the central region of the wafer and an edge gas guiding hole with the gas outlet facing the edge region of the wafer. The diameters of the central gas guiding hole, the edge gas guiding hole and the first axial hole are matched. When the central gas guiding hole and the edge gas guiding hole are aligned and connected with the first axial hole, they form a first flow channel and a second flow channel. The second layer of the grid is rotated circumferentially to connect the first or second flow channel, thereby adjusting the ratio of plasma flux entering the central region to the edge region.

2. The double-layer plasma grid according to claim 1, characterized in that, The air guiding structure further includes a second axial hole that matches the diameter of the first axial hole and extends along the axial direction; the first layer of grid has a plurality of arc segments that correspond one-to-one with the air guiding structure, and a first axial hole is provided for each arc segment of the air guiding structure. When the second axial hole is aligned and connected with the first axial hole, a third flow channel is formed; the circumferential rotation of the second layer of grid makes any one of the first flow channel, the second flow channel and the third flow channel connected.

3. The double-layer plasma grid according to claim 1, characterized in that, The air guiding structure also includes a first sub-axial hole and a second sub-axial hole that match the diameter of the first axial hole and are axially connected. The central air guiding hole, the first sub-axial hole, the edge air guiding hole and the second sub-axial hole in the same air guiding structure are arranged sequentially in the circumferential direction. The first layer of grid is provided with a number of arc-shaped segments, and each arc-shaped segment of the air guiding structure is provided with two first axial holes. When the first sub-axial hole and the second sub-axial hole are aligned and connected with the first axial hole, they form the fourth and fifth flow channels, respectively. The circumferential rotation of the second layer of the grid connects the fourth flow channel and the first flow channel, or connects the fourth flow channel and the second flow channel, or connects the second flow channel and the fifth flow channel.

4. The double-layer plasma grid according to claim 3, characterized in that, The second layer of the grid includes an inner ring region corresponding to the center region of the wafer and an outer ring region corresponding to the edge region of the wafer; Both the inner and outer ring regions are provided with the air guiding structure, and the number of the first, second, fourth, and fifth flow guiding channels in the inner and outer ring regions is the same.

5. The double-layer plasma grid according to claim 1, characterized in that, The central air guide hole includes: The first axial section is disposed along the axial direction in the second layer of the grid; The first inclined section is located at the bottom of the first axial section and communicates with the first axial section; the extension structure of the gas outlet end of the first inclined section extends toward the central region of the wafer.

6. The double-layer plasma grid according to claim 5, characterized in that, The edge air vent includes: The second axial section is disposed along the axial direction in the second layer of the grid. The second inclined section is located at the bottom of the second axial section and communicates with the second axial section; the extension structure of the gas outlet end of the second inclined section extends toward the edge region of the wafer.

7. The double-layer plasma grid according to claim 6, characterized in that, It also includes flow regulators; Each of the central air guide holes and each of the edge air guide holes is provided with a flow regulating component; The flow regulating component includes a blocking part, at least a portion of which extends from the outlet end of the first inclined section or the outlet end of the second inclined section into the first inclined section or the second inclined section, so that the circumferential outer wall of the blocking part forms a flow passage with the circumferential inner wall of the first inclined section or the second inclined section, and the blocking area of ​​the blocking part decreases toward the inlet end of the central air guide hole or the inlet end of the edge air guide hole. The plasma flux ratio between the central region and the edge region can be adjusted by controlling the movement of the blocking part toward or away from the air inlet end of the central air guide or the air inlet end of the edge air guide.

8. The double-layer plasma grid according to claim 7, characterized in that, The flow regulating component further includes a driving part, which is disposed on the second layer of the grid, and its driving end extends along the axial direction of the first inclined section or the second inclined section and is connected to the blocking part. By controlling the movement of the blocking part toward or away from the air inlet end of the central air guide hole or the air inlet end of the edge air guide hole, the extension amount of the blocking part into the first inclined section or the second inclined section can be adjusted.

9. The double-layer plasma grid according to claim 1, characterized in that, The sidewalls opposite to the first window and the second layer of the grid form a first docking portion and a second docking portion; The first docking portion has a support groove that extends circumferentially. A rotating component is fixed on the second docking part. The rotating component is movably disposed in the support groove, and a first driving component is provided at its end located in the support groove. Several second driving components are provided at circumferential intervals in each area of ​​the inner sidewall of the support groove. The first driving component and several second driving components are respectively connected to an independent power supply. By controlling the power on and off of each second driving component, the first driving component is attracted and driven to carry the second layer of grid mesh to make circumferential rotational movement.

10. The double-layer plasma grid according to claim 9, characterized in that, It also includes at least one angle positioning sensor; At least one of the angle positioning sensors is disposed on the inner sidewall of the support groove. The angle positioning sensor is used to detect the real-time rotation angle of the first driving member and feed the angle signal back to the control module of the peripheral device to realize the control of the rotational motion of the second layer of grid.

11. The double-layer plasma grid according to claim 1, characterized in that, It also includes a third driving component, which is located on the inner sidewall of the first window and its driving end is connected to the second layer of the grid. The third driving component drives the second layer of the grid to move up and down along the axial direction to adjust the spacing between the second layer of the grid and the first layer of the grid.

12. The double-layer plasma grid according to claim 1, characterized in that, The second layer of the grid has a wear-resistant bonding layer on the side facing the first layer of the grid. The surface roughness of the wear-resistant bonding layer is less than or equal to 0.8 μm, so as to reduce the frictional loss between the second layer of the grid and the first layer of the grid during the rotation of the second layer of the grid.

13. A plasma processing device, characterized in that, The device includes a processing chamber, a dielectric window, a fixed base, and a stage, as well as a double-layer plasma grid as described in any one of claims 1 to 12. The fixed base is disposed between the processing chamber and the dielectric window, and the top of the processing chamber is provided with a second window adapted to and communicating with the first window in the fixed base. The stage is disposed in the processing chamber, and its top is used to support a wafer.

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