Plasma processing apparatus and control method
By adding cleaning positions and limiting pads to the plasma processing device, the problems of low cleaning efficiency and device damage caused by etching byproduct deposition are solved, achieving more efficient cleaning and a longer device lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ADVANCED MICRO FAB EQUIP INC CHINA
- Filing Date
- 2024-12-02
- Publication Date
- 2026-06-02
AI Technical Summary
As the etching depth increases, existing plasma processing devices cause etching byproducts to deposit on the inner wall of the reaction chamber, making it impossible for the cleaning plasma to effectively clean them, which affects wafer quality and shortens the device life.
A cleaning position is added between the moving ring and the lower electrode. The moving ring is raised by a limiting shim to increase the gap, improve the efficiency of cleaning plasma flow, and reduce the bombardment of the inner wall.
It effectively cleans the etching byproducts on the inner wall of the reaction chamber, extends the service life of the device, reduces maintenance costs, and improves production efficiency.
Smart Images
Figure CN122136251A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a plasma processing apparatus and control method. Background Technology
[0002] In the semiconductor manufacturing field, plasma processing equipment is used to perform processes such as etching and thin film deposition on wafers to fabricate semiconductor devices. Commonly used plasma processing equipment includes capacitively coupled plasma etching equipment, which is a device that uses a radio frequency power supply applied to electrodes to generate plasma in a reaction chamber through capacitive coupling for etching. To confine the plasma above the base, a movable ring that can be raised and lowered is set in the reaction chamber.
[0003] During the etching process, the moving ring descends above the lower electrode, effectively confining the plasma above the wafer to maximize plasma participation in the etching process. At this point, the moving ring is positioned at the process position. During wafer transfer, the moving ring moves upward, exposing the transfer port located on the sidewall of the reaction chamber, allowing the wafer to be transferred into or out of the reaction chamber. At this point, the moving ring is positioned at the transfer position. Under these requirements, the moving ring only needs to be in either the process or transfer position. However, as the etching depth increases, etching byproducts are needed to protect the sidewalls of deep holes, thus increasing the etching depth. Simultaneously, excess etching byproducts from the deep hole etching process are sputtered from the wafer surface and gradually diffuse and deposit onto the inner wall of the reaction chamber, especially on the inner wall corresponding to the gap between the moving ring and the lower electrode.
[0004] Because the self-cleaning process of the reaction chamber is performed when the moving ring is in the process position, and the gap between the moving ring and the lower electrode is narrow when the moving ring is in the process position, the cleaning plasma formed by the cleaning gas cannot pass through this gap to effectively clean the etching byproducts deposited on the inner wall of the reaction chamber. As the process hours accumulate, etching byproducts also accumulate in the reaction chamber. When the etching byproducts accumulate to a certain extent, they will peel off from the inner wall of the reaction chamber and drift above the wafer, causing arc discharge, damaging the wafer, and affecting the process. Summary of the Invention
[0005] The purpose of this invention is to provide a plasma processing device and control method, which adds a cleaning position between the process position and the wafer transfer position. In the cleaning position, the gap between the moving ring and the lower electrode is larger, which improves the efficiency of cleaning the reaction chamber, reduces the damage of plasma to the inner wall of the reaction chamber, extends the service life of the plasma processing device, improves production efficiency, and reduces maintenance costs.
[0006] To achieve the above objectives, the present invention provides a plasma processing apparatus, comprising: a vacuum reaction chamber having an upper electrode and a lower electrode therein, forming a plasma processing area between the upper and lower electrodes; a sleeve extending vertically through the top wall of the vacuum reaction chamber; a movable ring surrounding the upper electrode and movable vertically between a transfer position and a process position; a support rod at the top of the movable ring, the top of the support rod passing through the sleeve; a first driving mechanism disposed at the top of the support rod; and a limiting pad connected to the first driving mechanism, the first driving mechanism controlling the limiting pad to move in a direction perpendicular to the support rod; when the limiting pad moves to the outer circumferential direction of the support rod and is pressed against the sleeve by the top of the support rod, relative to the process position, the movable ring is raised by at least the height of the limiting pad, placing the movable ring in a cleaning position for performing a cleaning process.
[0007] Optionally, the height of the limiting pad is in the range of 1 to 30 mm.
[0008] Optionally, the limiting pad includes an opening facing the support rod, allowing the limiting pad to be engaged with the circumferentially outer side of the support rod.
[0009] Optionally, the first driving mechanism includes a first driving device, a first connecting rod, and a guide shaft; the limiting pad is sleeved on the guide shaft and can move up and down along the guide shaft; the first driving device is disposed at the top end of the support rod; the first connecting rod includes a first end and a second end opposite to each other; the first end of the first connecting rod is connected to the first driving device, and the lower surface of the second end is connected to the guide shaft, for driving the guide shaft and the limiting pad to move in a direction perpendicular to the support rod.
[0010] Optionally, the plasma processing device further includes a second driving mechanism, which includes a second driving device and a second connecting rod. The second driving device is disposed above the top wall of the vacuum reaction chamber. The second connecting rod includes a third end and a fourth end opposite to each other. The third end of the second connecting rod is connected to the second driving device, and the fourth end is connected to the top end of the support rod, for transmitting the power of the second driving device to the support rod and driving the support rod to move in the vertical direction. The first driving device is fixed to the fourth end of the second connecting rod.
[0011] Optionally, the guide shaft includes an opposite top end and a bottom end, and the bottom end of the guide shaft is provided with a base, the diameter of which is larger than the diameter of the guide shaft, for supporting the limiting pad.
[0012] Optionally, the fourth end of the second connecting rod is provided with an extension, and the extension is provided with a guide groove that runs vertically through the rod. The guide shaft is disposed in the guide groove and can move along the guide groove.
[0013] Optionally, the height of the sleeve is greater than or equal to the height of the second driving device; the sleeve is provided with a retractable seal, which is arranged around the circumference of the support rod, and the bottom end of the retractable seal is connected to the sleeve, and the top end is connected to the circumferential side wall of the support rod.
[0014] Optionally, the width of the first driving device is less than or equal to 40 mm, the height is less than or equal to 40 mm, and the length is less than or equal to 100 mm.
[0015] Optionally, the first driving device is any one of a cylinder, a hydraulic cylinder, or a motor; the second driving device is any one of a cylinder, a hydraulic cylinder, or a motor.
[0016] Optionally, the cylinder or hydraulic cylinder is a two-stage type.
[0017] Optionally, the limiting gasket is made of one or more of polyetheretherketone, polyetherimide, or polytetrafluoroethylene.
[0018] Optionally, the plasma processing device further includes an adjustment mechanism disposed outside the vacuum reaction chamber, comprising: a receiving box containing a plurality of the limiting pads; and a gripping device disposed outside the receiving box for gripping the limiting pads from the receiving box and securing the limiting pads onto a support rod or guide shaft.
[0019] The present invention also provides a control method for the plasma processing apparatus as described above, comprising:
[0020] When the plasma processing device performs the reaction process, the first drive mechanism controls the limiting pad to move to a position away from the support rod, the moving ring moves downward from the transfer position to the process position, the top of the support rod is flush with the upper surface of the sleeve, the inner wall of the moving ring surrounds the plasma processing area, and there is a first gap between the lower end of the moving ring and the lower electrode.
[0021] When the plasma treatment device performs the cleaning process, the first drive mechanism controls the limiting pad to move to the circumference of the support rod. The moving ring moves downward, driving the first drive mechanism to move downward. When the limiting pad contacts the sleeve, the sleeve provides an upward support force to the limiting pad. The limiting pad moves to the top of the support rod and is pressed onto the sleeve by the top of the support rod. The inner wall of the moving ring surrounds the plasma treatment area, and there is a second gap between the lower end of the moving ring and the lower electrode; the second gap is larger than the first gap.
[0022] Optionally, when the moving ring is in the transfer position, the inner wall of the moving ring is circumferentially opposite to the upper electrode, and there is a third gap between the lower end of the moving ring and the lower electrode; the third gap is larger than the second gap.
[0023] Optionally, if the moving ring moves from the process position to the cleaning position, the control method further includes: the moving ring moves upward a first distance to form a space for the limiting gasket to move between the upper surface of the sleeve and the top end of the support rod, wherein the first distance is greater than the thickness of the limiting gasket and less than or equal to the height of the moving ring at the transfer plate position.
[0024] Compared with the prior art, the technical solution of the present invention has at least the following advantages:
[0025] In the plasma processing apparatus provided by this invention, by setting a limiting shim that can move along a perpendicular support rod, a cleaning position is added between the process position and the wafer transfer position when the limiting shim is engaged at the top of the support rod. Compared with the process position, the moving ring in the cleaning position is raised by at least one limiting shim, increasing the gap between the lower end of the moving ring and the lower electrode, thereby improving the flow efficiency of the cleaning plasma flowing out of the gap and enhancing the reaction efficiency between the cleaning plasma and the etching byproducts. This allows the cleaning plasma to effectively clean the etching byproducts accumulated on the inner wall of the vacuum reaction chamber near the moving ring and the lower electrode. At the same time, since the moving ring is only raised by the thickness of the limiting shim, the cleaning plasma can only flow out through the gap between the moving ring and the lower electrode, reducing the area of the cleaning plasma directly contacting the inner wall of the vacuum reaction chamber. This avoids the cleaning plasma bombarding the inner wall of the vacuum reaction chamber where no etching byproducts have been deposited, extending the service life of the vacuum reaction chamber and reducing maintenance costs. Attached Figure Description
[0026] Figure 1 This is a schematic cross-sectional view of a plasma processing device;
[0027] Figure 2 This is a cross-sectional schematic diagram of a plasma processing apparatus of the present invention performing a wafer transfer process.
[0028] Figure 3 This is a cross-sectional schematic diagram of a plasma processing device according to the present invention performing a reaction process.
[0029] Figure 4 This is a cross-sectional schematic diagram of a plasma treatment apparatus of the present invention performing a cleaning process.
[0030] Figure 5 for Figure 2 An enlarged schematic diagram of the structure outlined by the dashed lines in the diagram;
[0031] Figure 6 This is an enlarged schematic diagram showing the limiting gasket located above the sleeve in a plasma processing device according to the present invention;
[0032] Figure 7 for Figure 4 An enlarged schematic diagram of the structure outlined by the dashed lines in the diagram;
[0033] Figure 8 This is a top view schematic diagram of the second connecting rod in a plasma processing device according to the present invention;
[0034] Figure 9 This is a flowchart of a control method for a plasma processing apparatus according to the present invention. Detailed Implementation
[0035] The technical solutions, structural features, achieved objectives, and effects of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention.
[0036] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.
[0037] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.
[0038] like Figure 1 The plasma processing apparatus shown includes a reaction chamber 10, within which a moving ring 11 is provided for limiting plasma distribution. The moving ring 11 can move vertically within the reaction chamber 10 to a wafer transfer position or a process position. When the moving ring 11 is in the wafer transfer position, it performs the in-cavity and out-of-cavity transfer process of the wafer W; when the moving ring 11 is in the process position (e.g., ... Figure 1 As shown, the moving ring 11 is located above the lower electrode 12, and there is a gap between the moving ring 11 and the lower electrode 12. This gap is used to perform the etching or cleaning process of the wafer W. That is, the position of the moving ring 11 is the same during the etching process and the cleaning process. However, as the etching depth increases, the etching by-products 13 generated by the etching will be concentrated and deposited on the inner wall of the reaction chamber 10 corresponding to the gap. At the same time, because the gap between the moving ring 11 and the lower electrode 12 is narrow, the cleaning plasma formed by the cleaning gas cannot effectively clean the etching by-products 13 through the gap. The accumulated excessive etching by-products 13 will drift into the plasma region 14, thereby causing arc discharge, resulting in damage to the wafer W and affecting subsequent processes.
[0039] To address the aforementioned shortcomings, this invention adds a movable limiting pad. When the limiting pad is engaged at the top of the moving ring, it restricts the descent height of the moving ring, raising it by at least the thickness of the limiting pad. In other words, a cleaning position is added between the process position and the transfer position. In the cleaning position, the gap between the moving ring and the lower electrode is larger, allowing the cleaning plasma to effectively clean the byproducts deposited on the inner wall of the reaction chamber, while preventing damage to the inner wall of the reaction chamber by the cleaning plasma.
[0040] Based on the above inventive concept, please refer to Figure 2 , Figure 2This is a cross-sectional view of a plasma processing apparatus 200 provided in an embodiment of the present invention. The plasma processing apparatus 200 includes: a vacuum reaction chamber 201, in which an upper electrode 211 and a lower electrode 212 are disposed; a wafer transfer port 213 is provided on the side wall of the vacuum reaction chamber 201 for transferring wafer W; the lower electrode 212 is disposed opposite to the upper electrode 211. In this embodiment, the plasma processing apparatus 200 is specifically a capacitively coupled plasma etching device; the upper electrode 211 is a gas spray head; the gas spray head is connected to a gas supply device 208 for supplying gas to the vacuum reaction chamber 201. The reaction gas or cleaning gas is delivered; the lower electrode 212 serves as a base for supporting the wafer W, and a plasma processing region is formed between the upper electrode 211 and the lower electrode 212; the upper electrode 211 or the lower electrode 212 is connected to at least one radio frequency power supply (not shown in the figure), generating a radio frequency electric field between the upper electrode 211 and the lower electrode 212 to dissociate the reaction gas or cleaning gas into plasma, which is used to perform an etching process on the surface of the wafer W; further specific etching principles and related components are known in the art and will not be elaborated here. The main inventive point of this application is:
[0041] Please combine Figures 2-8 As shown, the top of the vacuum reaction chamber 201 is provided with a sleeve 202 that extends vertically through its top wall; a movable ring 203 is arranged around the circumference of the upper electrode 211, and can move vertically at the plate transfer position (e.g., ...). Figure 2 (as shown) and process location (e.g.) Figure 3 The moving ring 203 moves between the sleeve 202 and the support rod 204 at its top end. The top end of the support rod 204 passes through the sleeve 202 and is used to transmit driving force to move the moving ring 203 vertically. A first driving mechanism 205 is provided at the top end of the support rod 204 and moves together with the support rod 204. A limiting pad 206 is connected to the first driving mechanism 205. The first driving mechanism 205 controls the limiting pad 206 to move in a direction perpendicular to the support rod 204, that is, the first driving mechanism 205 controls the limiting pad 206 to move in a horizontal direction. When the limiting pad 206 moves toward the support rod 204 and moves to the outer circumferential direction of the support rod 204, and is pressed onto the sleeve 202 by the top end of the support rod 204, the moving ring 203 is raised by at least the height of the limiting pad 206 relative to the process position, so that the moving ring 203 is in a cleaning position for performing a cleaning process (such as...). Figure 4 (As shown). The cleaning position is located between the process position and the wafer transfer position.
[0042] Specifically, such as Figure 3As shown, when the plasma processing device 200 performs the reaction process, the first driving mechanism 205 controls the limiting pad 206 to move away from the support rod 204, and the moving ring 203 moves downward from the transfer position to the process position. The top end of the support rod 204 is flush with the upper surface of the sleeve 202. The inner wall of the moving ring 203 surrounds the plasma processing area, and there is a first gap d1 between the lower end of the moving ring 203 and the lower electrode 212 to form a plasma flow path. However, since the first gap d1 is small, if the moving ring 203 is in this process position and a cleaning process is performed, the low flow efficiency of the cleaning plasma makes it impossible to effectively clean the etching byproducts deposited on the inner wall of the vacuum reaction chamber 201 corresponding to the first gap d1.
[0043] Therefore, as Figure 4 and Figure 7 As shown, when the plasma treatment device 200 performs the cleaning process, the first drive mechanism 205 controls the limiting pad 206 to move above the sleeve 202. The support rod 204 transmits driving force to move the moving ring 203 downward, driving the first drive mechanism 205 downward. When the limiting pad 206 contacts the sleeve 202, the sleeve 202 provides upward support force to the limiting pad 206. The limiting pad 206 moves to the top of the support rod 204 and is pressed onto the sleeve 202 by the top of the support rod 204. The inner wall of the moving ring 203 surrounds the plasma treatment area, and the moving ring 203 is raised by at least one limiting pad 206. At this time, there is a second gap d2 between the lower end of the moving ring 203 and the lower electrode 212. The second gap d2 is greater than the first gap d2. The gap d1 improves the flow efficiency of the cleaning plasma from the second gap d2, thereby enhancing the reaction efficiency between the cleaning plasma and the etching byproducts. This allows the cleaning plasma to more effectively remove the etching byproducts accumulated on the inner wall of the vacuum reaction chamber 201 near the moving ring 203 and the lower electrode 212. Simultaneously, since the moving ring 203 is only raised by the thickness of the limiting pad 206, most of the inner wall of the vacuum reaction chamber 201 is still covered and protected by the moving ring 203. In other words, the cleaning plasma is confined within the moving ring 203 and can only flow out through the second gap d2 between the moving ring 203 and the lower electrode 212. This reduces the area of direct contact between the cleaning plasma and the inner wall of the vacuum reaction chamber, thus preventing the cleaning plasma from bombarding the inner wall of the vacuum reaction chamber 201 where no etching byproducts have been deposited, and extending the service life of the vacuum reaction chamber 201.
[0044] Optionally, the height of the limiting gasket 206 ranges from 1 to 30 mm, and can be set according to the cleaning process requirements. The limiting gasket 206 is made of one or more of polyetheretherketone, polyetherimide, or polytetrafluoroethylene, and has high strength and high toughness characteristics, making it resistant to significant deformation when compressed.
[0045] Furthermore, such as Figure 5 As shown, the first driving mechanism 205 includes a first driving device 251, a first connecting rod 252, and a guide shaft 253; the limiting pad 206 is sleeved on the guide shaft 253 and can move up and down along the guide shaft 253; the first driving device 251 is disposed at the top end of the support rod 204; the first connecting rod 252 includes a first end and a second end opposite to each other; the first end of the first connecting rod 252 is connected to the first driving device 251, and the lower surface of the second end is connected to the guide shaft 253. The first connecting rod 252 is used to drive the guide shaft 253 and the limiting pad 206 to move in a direction perpendicular to the support rod 204, so that the limiting pad 206 can move to the circumferential outer side of the support rod 204.
[0046] Optionally, the width of the first driving device 251 is less than or equal to 40mm, the height is less than or equal to 40mm, and the length is less than or equal to 100mm. This is because the top space of the support rod 204 is limited. If the first driving device 251 is too large, it may bump into other components or cannot be installed on the top of the support rod 204. The first driving device 251 can be any one of a cylinder, a hydraulic cylinder, or a motor. In this embodiment, since the limiting shim 206 can be located at two positions: away from the support rod 204 and on the outer periphery of the support rod 204, a two-stage cylinder or hydraulic cylinder is sufficient to meet the displacement requirements of the limiting shim 206. In other embodiments, the type and size of the first driving device 251 can be selected according to requirements.
[0047] Furthermore, such as Figure 5 and Figure 8 As shown, the guide shaft 253 includes a top end and a bottom end. The top end of the guide shaft 253 is connected to the lower surface of the second end of the first connecting rod 252. The bottom end of the guide shaft 253 is provided with a base 2531. The diameter of the base 2531 is larger than the diameter of the guide shaft 253, which is used to support the limiting pad 206 and prevent the limiting pad 206 from falling off the bottom end of the guide shaft 253. Specifically, as shown... Figures 5-7 As shown, when the moving ring 203 is in the transfer position, the guide shaft 253 and the limiting pad 206 are in a position away from the support rod 204, and the limiting pad 206 is supported by the base 2531; when the moving ring 203 moves from the transfer position to the cleaning position, as... Figure 6As shown, firstly, the guide shaft 253 moves toward the support rod 204, causing the limiting pad 206 to move to the circumferential outer side of the support rod 204 and above the sleeve 202; then, the moving ring 203 descends, and when the limiting pad 206 contacts the upper surface of the sleeve 202, the sleeve 202 provides an upward support force, causing the limiting pad 206 to separate from the base 2531 and move upward along the guide shaft 253 until the first driving device 251 at the top of the support rod 204 presses the limiting pad 206 onto the sleeve 202 (e.g., Figure 7 As shown, the moving ring 203 is raised by the thickness of a limiting pad 206, at which point the moving ring 203 is in the clean position.
[0048] As an optional embodiment, the limiting pad 206 further includes an opening facing the support rod 204, and the diameter of the opening is greater than or equal to the diameter of the support rod 204. This allows the limiting pad 206 to be engaged with the outer circumferential side of the support rod 204, improving the connection stability of the limiting pad 206 engaged with the support rod 204. This effectively prevents the limiting pad 206 from moving between the support rod 204 and the sleeve 202, thus avoiding changes in the height of the moving ring 203 and ensuring the effectiveness of the cleaning process.
[0049] like Figures 2-7 As shown, the plasma processing device 200 further includes a second driving mechanism 207, which includes a second driving device 271 and a second connecting rod 272. The second driving device 271 is disposed above the top wall of the vacuum reaction chamber 201 and is used to drive the first driving mechanism 205 and the limiting pad 206 to move up and down. The second connecting rod 272 includes a third end and a fourth end. The third end of the second connecting rod 272 is connected to the second driving device 271, and the fourth end is connected to the top end of the support rod 204. The second connecting rod 272 is used to transmit the power of the second driving device 271 to the support rod 204, driving the support rod 204 to move in the vertical direction. The first driving device 251 is fixed on the fourth end of the second connecting rod 272 and moves simultaneously with the second connecting rod 272 and the support rod 204.
[0050] Optionally, the second driving device 271 can be any one of a cylinder, a hydraulic cylinder, or a motor. A two-stage cylinder or hydraulic cylinder is sufficient to meet the displacement requirements of the moving ring 203. By using a limiting washer 206 to hold the top of the support rod 204, the descent height of the moving ring 203 can be increased, ensuring the moving ring 203 is in a clean position. This is because the top space of the vacuum reaction chamber 201 is limited, and the volume of a two-stage driving device is highly compatible with this top space. Furthermore, most existing technologies use two-stage driving devices, eliminating the need for a second replacement of the second driving device to control the clean position of the moving ring 203, significantly reducing production costs. Further, cylinders or hydraulic cylinders with three or more stages are too large to be installed at the top of the vacuum reaction chamber; miniaturizing cylinders with three or more stages would result in a smaller cylinder or hydraulic cylinder, which would not provide sufficient pulling force.
[0051] Furthermore, such as Figure 5 and Figure 8 As shown, the fourth end of the second connecting rod 272 is provided with an extension 273. The extension 273 is provided with a guide groove 2731 that runs vertically through the rod. The guide shaft 253 is disposed in the guide groove 2731. The guide groove 2731 guides the guide shaft 253, allowing the guide shaft 253 to move along the guide groove 2731 toward or away from the first driving device 251, thus preventing the guide shaft 253 from deviating. This ensures that the limiting pad 206 can be accurately engaged on the circumferential outer side of the support rod 204, ensuring that during subsequent cleaning processes, the moving ring 203 can be raised by a certain thickness to form the second gap d2, thereby increasing the flow rate of the cleaning plasma and achieving efficient cleaning of etching byproducts. In some embodiments, the second connecting rod 272 and the extension 273 can be integrally formed.
[0052] Among them, such as Figures 2-7As shown, the height of the sleeve 202 is greater than or equal to the height of the second driving device 271, so that when the limiting gasket 206 is clamped between the second connecting rod 272 and the sleeve 202, it can elevate the moving ring 203. Furthermore, to ensure the vacuum seal within the vacuum reaction chamber 201, a retractable sealing element 221 is provided inside the sleeve 202. The retractable sealing element 221 is arranged around the support rod 204 in the circumferential direction, and the bottom end of the retractable sealing element 221 is flush with the sleeve 202. 2. The top end of the retractable seal 221 is connected to the circumferential side wall of the support rod 204, dividing the vacuum reaction chamber 201 into a vacuum side and an atmospheric side. The upper side of the retractable seal 221 is the atmospheric side (i.e., the environment where the top end of the support rod 204, the first drive mechanism 205, the second drive mechanism 207, and the limiting gasket 206 are located). When the limiting gasket 206 is squeezed, particulate pollutants may be generated. By setting the retractable seal 221, particulate pollutants generated on the atmospheric side can be effectively prevented from entering the vacuum reaction chamber 201.
[0053] Furthermore, such as Figure 2 As shown, the plasma processing device 200 further includes an adjustment mechanism 209, which is disposed outside the vacuum reaction chamber 201. This mechanism includes: a receiving box 291 containing a plurality of the limiting pads 206; and a gripping device (such as a robotic arm, not shown in the figure), disposed outside the receiving box 291, for gripping the limiting pads 206 from the receiving box 291 and securing the limiting pads 206 onto the support rod 204 or guide shaft 253. By setting the adjustment mechanism 209, the number of limiting pads 206 can be adjusted according to actual process requirements, raising the moving ring 203 to different cleaning positions to clean etching byproducts at different heights on the inner wall of the vacuum reaction chamber 201.
[0054] The present invention also provides a control method for a plasma processing device, referring to... Figures 2-7 and Figure 9 The control method includes: when the plasma processing device 200 performs a reaction process, the first driving mechanism 205 controls the limiting pad 206 to move to a position away from the support rod 204, the moving ring 203 moves downward from the transfer position to the process position, and the top end of the support rod 204 is flush with the upper surface of the sleeve 202 (e.g., Figure 3 As shown, the inner wall of the moving ring 203 surrounds the plasma processing area, and a first gap d1 exists between the lower end of the moving ring 203 and the lower electrode 212. In this embodiment, a reaction gas is input into the vacuum reaction chamber 201 through the upper electrode 211. The reaction gas is dissociated into plasma and used to etch the wafer W.
[0055] When the plasma treatment device 200 performs the cleaning process, the first drive mechanism 205 controls the limiting pad 206 to move to the circumference of the support rod 204, and the moving ring 203 moves downward, driving the first drive mechanism 205 to move downward. When the limiting pad 206 contacts the sleeve 202, the sleeve 202 provides an upward support force to the limiting pad 206. The limiting pad 206 moves to the top of the support rod 204 and is pressed onto the sleeve 202 by the first drive mechanism 205 at the top of the support rod 204. The inner wall of the moving ring 203 surrounds the plasma treatment area, and there is a second gap d2 between the lower end of the moving ring 203 and the lower electrode 212; the second gap d2 is greater than the first gap d1. In this embodiment, a cleaning gas with cleaning capabilities is input into the vacuum reaction chamber 201 through the upper electrode 211. After the cleaning gas is ionized into cleaning plasma, it reacts chemically with the etching byproducts accumulated near the moving ring 203 and the lower electrode 212 on the inner wall of the vacuum reaction chamber 201 through the second gap d2, thereby removing the deposited etching byproducts and allowing the reaction products to be discharged from the vacuum reaction chamber 201 with the gas.
[0056] When the plasma processing device 200 performs the wafer transfer process, the moving ring 203 moves upward to the wafer transfer position. The inner wall of the moving ring 203 is circumferentially opposite to the upper electrode 211, and there is a third gap d3 between the lower end of the moving ring 203 and the lower electrode 212. The third gap d3 is larger than the second gap d2. The third gap d3 is at least partially corresponding to the wafer transfer port 213, providing transfer space for the wafer W.
[0057] In another embodiment, when the plasma treatment device 200 finishes the reaction process and directly performs the cleaning process, the moving ring 203 needs to move from the process position to the cleaning position. Since when the moving ring 203 is in the process position, the top end of the support rod 204 is flush with the upper surface of the sleeve 202, that is, the top end of the support rod 204 is in close contact with the upper surface of the sleeve 202, causing the limiting pad 206 to be unable to move to the circumference of the support rod 204. Therefore, this process also includes: the moving ring 203 moving upward a first distance to form a moving space for the limiting pad 206 between the upper surface of the sleeve 202 and the top end of the support rod 204, so that the limiting pad 206 can move to the circumference of the support rod 204. Subsequently, the moving ring 203 moves downward, causing the first driving mechanism 205 to move downward. When the limiting pad 206 contacts the sleeve 202, the sleeve 202 provides an upward supporting force to the limiting pad 206. The limiting pad 206 moves to the top of the support rod 204 and is pressed onto the sleeve 202 by the first driving mechanism 205 at the top of the support rod 204, causing the moving ring 203 to move to the cleaning position. The first distance is greater than the thickness of the limiting pad 206 and less than or equal to the height of the moving ring 203 at the transfer position.
[0058] In summary, the plasma processing apparatus and control method provided by this invention, by setting a limiting pad 206 that can move perpendicular to the support rod 204, when the limiting pad 206 is engaged at the top of the support rod 204, compared to the process position, the moving ring 203 in the cleaning position is raised by at least one limiting pad 206, increasing the gap between the lower end of the moving ring 203 and the lower electrode 212, thereby improving the flow efficiency of the cleaning plasma out of the gap. This allows the cleaning plasma to more effectively clean the etching byproducts accumulated on the inner wall of the vacuum reaction chamber 201 near the moving ring 203 and the lower electrode 212, while also preventing the cleaning plasma from bombarding the inner wall of the vacuum reaction chamber 201 where no etching byproducts have been deposited, thus extending the service life of the vacuum reaction chamber 201 and reducing maintenance costs.
[0059] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.
Claims
1. A plasma processing device, characterized in that, include: A vacuum reaction chamber is provided with an upper electrode and a lower electrode, and a plasma processing area is formed between the upper electrode and the lower electrode. A sleeve is provided that extends vertically through the top wall of the vacuum reaction chamber; A movable ring, which is arranged around the circumference of the upper electrode, can move vertically between the wafer transfer position and the process position. The top end of the movable ring is provided with a support rod, and the top end of the support rod passes through the sleeve; A first drive mechanism is disposed at the top of the support rod; A limiting pad is connected to the first driving mechanism, which controls the limiting pad to move in a direction perpendicular to the support rod. When the limiting pad moves to the circumferential outer side of the support rod and is pressed onto the sleeve by the top of the support rod, the moving ring is raised by at least the height of the limiting pad relative to the process position, so that the moving ring is in the cleaning position for performing the cleaning process.
2. The plasma processing apparatus as described in claim 1, characterized in that, The height range of the limiting pad is 1 to 30 mm.
3. The plasma processing apparatus as described in claim 1, characterized in that, The limiting pad includes an opening facing the support rod, allowing the limiting pad to be engaged with the outer circumferential side of the support rod.
4. The plasma processing apparatus as described in claim 1, characterized in that, The first driving mechanism includes a first driving device, a first connecting rod, and a guide shaft; the limiting pad is sleeved on the guide shaft and can move up and down along the guide shaft; the first driving device is disposed at the top end of the support rod; the first connecting rod includes a first end and a second end opposite to each other; the first end of the first connecting rod is connected to the first driving device, and the lower surface of the second end is connected to the guide shaft, for driving the guide shaft and the limiting pad to move in a direction perpendicular to the support rod.
5. The plasma processing apparatus as described in claim 4, characterized in that, It also includes a second driving mechanism, which includes a second driving device and a second connecting rod; the second driving device is disposed above the top wall of the vacuum reaction chamber; the second connecting rod includes a third end and a fourth end opposite to each other; the third end of the second connecting rod is connected to the second driving device, and the fourth end is connected to the top end of the support rod, for transmitting the power of the second driving device to the support rod, driving the support rod to move in the vertical direction; the first driving device is fixed on the fourth end of the second connecting rod.
6. The plasma processing apparatus as described in claim 4, characterized in that, The guide shaft includes a top end and a bottom end. The top end of the guide shaft is connected to the second end of the first connecting rod. The bottom end of the guide shaft is provided with a base. The diameter of the base is larger than the diameter of the guide shaft and is used to support the limiting pad.
7. The plasma processing apparatus as described in claim 5, characterized in that, The fourth end of the second connecting rod is provided with an extension, and the extension is provided with a guide groove that runs vertically through the rod. The guide shaft is disposed in the guide groove and can move along the guide groove.
8. The plasma processing apparatus as described in claim 5, characterized in that, The height of the sleeve is greater than or equal to the height of the second driving device; the sleeve is provided with a retractable seal, which is arranged around the circumference of the support rod, and the bottom end of the retractable seal is connected to the sleeve, and the top end is connected to the circumferential side wall of the support rod.
9. The plasma processing apparatus as described in claim 4, characterized in that, The width of the first driving device is less than or equal to 40mm, the height is less than or equal to 40mm, and the length is less than or equal to 100mm.
10. The plasma processing apparatus as described in claim 5, characterized in that, The first driving device is any one of a cylinder, a hydraulic cylinder, or a motor; the second driving device is any one of a cylinder, a hydraulic cylinder, or a motor.
11. The plasma processing apparatus as claimed in claim 10, characterized in that, The cylinder or hydraulic cylinder is a two-stage type.
12. The plasma processing apparatus as claimed in claim 1, characterized in that, The limiting gasket is made of one or more of polyetheretherketone, polyetherimide, or polytetrafluoroethylene.
13. The plasma processing apparatus as described in claim 4, characterized in that, It also includes an adjustment mechanism, which is located outside the vacuum reaction chamber, comprising: a receiving box containing a plurality of the limiting pads; and a gripping device located outside the receiving box for gripping the limiting pads from the receiving box and securing the limiting pads onto a support rod or guide shaft.
14. A control method for a plasma processing apparatus as described in any one of claims 1 to 13, characterized in that, include: When the plasma processing device performs the reaction process, the first drive mechanism controls the limiting pad to move to a position away from the support rod, the moving ring moves downward from the transfer position to the process position, the top of the support rod is flush with the upper surface of the sleeve, the inner wall of the moving ring surrounds the plasma processing area, and there is a first gap between the lower end of the moving ring and the lower electrode. When the plasma treatment device performs the cleaning process, the first drive mechanism controls the limiting pad to move to the circumference of the support rod. The moving ring moves downward, driving the first drive mechanism to move downward. When the limiting pad contacts the sleeve, the sleeve provides an upward support force to the limiting pad. The limiting pad moves to the top of the support rod and is pressed onto the sleeve by the top of the support rod. The inner wall of the moving ring surrounds the plasma treatment area, and there is a second gap between the lower end of the moving ring and the lower electrode; the second gap is larger than the first gap.
15. The control method as described in claim 14, characterized in that, When the moving ring is in the transfer position, the inner wall of the moving ring is circumferentially opposite to the upper electrode, and there is a third gap between the lower end of the moving ring and the lower electrode; the third gap is larger than the second gap.
16. The control method as described in claim 14, characterized in that, If the moving ring moves from the process position to the cleaning position, the method further includes: the moving ring moves upward a first distance to form a moving space for the limiting gasket between the upper surface of the sleeve and the top end of the support rod, wherein the first distance is greater than the thickness of the limiting gasket and less than or equal to the height of the moving ring at the transfer plate position.