A plasma processing apparatus

Abstract

This invention provides a plasma processing device, comprising: a vacuum reaction chamber containing a liftable lower electrode assembly, with a radio frequency (RF) shielding substrate on the bottom wall of the vacuum reaction chamber; an RF guide rod, the top end of which is electrically connected to the lower part of the lower electrode assembly; a retractable sealing assembly that extends and retracts along the axial direction of the RF guide rod and is disposed between the liftable lower electrode assembly and the bottom wall of the vacuum reaction chamber; and a shielded transmission assembly, made of metal, for moving the liftable lower electrode assembly, comprising: a transmission rod, the top end of which is fixedly connected to the liftable lower electrode assembly; a flange seamlessly fitted onto the transmission rod; and a retractable shielding component circumferentially arranged around the transmission rod, the top end of which is electrically connected to the flange, and the bottom end of which is electrically connected to the RF shielding substrate. Its advantages are: the shielded transmission assembly possesses high tensile strength and high thread hardness, extending the service life of the transmission rod, and achieving RF shielding, effectively preventing equipment damage caused by RF leakage.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment, and more specifically to a plasma processing apparatus. Background Technology

[0002] In semiconductor chip manufacturing, numerous micro-fabrication processes are required. Commonly used microfabrication techniques include plasma etching, physical vapor deposition, and chemical vapor deposition. These processes are often accompanied by plasma-assisted processes, which are typically performed within a vacuum reaction chamber. The working principle of a vacuum reaction chamber generally involves introducing a suitable etchant or deposition source gas into the chamber, followed by the input of radio frequency energy to create plasma between the upper and lower electrodes, thus enabling the processing of the semiconductor wafer.

[0003] With advancements in manufacturing processes, variable electrode spacing designs have been applied in plasma etching equipment to dynamically adjust the edge etching rate and critical dimensions of semiconductor wafers. To achieve the adjustment of the upper and lower electrode spacing, a complete transmission device is installed in the plasma etching equipment, including a servo system, positioning mechanism, and transmission components. In existing technologies, using ordinary metal materials for the transmission rod poses a risk of radio frequency leakage; while using plastic materials cannot meet the requirements for high tensile strength and high thread hardness. Therefore, there is an urgent need for a plasma processing device that includes transmission components that conform to design principles to meet the transmission requirements of plasma etching equipment. Summary of the Invention

[0004] The purpose of this invention is to provide a plasma processing device that includes a transmission component with high tensile strength, high thread hardness, and radio frequency shielding, thereby achieving adjustment of the distance between the upper and lower electrodes while meeting the durability requirements of the transmission component and preventing radio frequency leakage.

[0005] To achieve the above objectives, the present invention provides a plasma processing apparatus comprising:

[0006] A vacuum reaction chamber is provided with a liftable lower electrode assembly inside, and a radio frequency shielding substrate is provided on the bottom wall of the vacuum reaction chamber.

[0007] The top end of the radio frequency guide rod is electrically connected to the lower part of the lower electrode assembly;

[0008] A retractable sealing assembly extends and retracts vertically along the axial direction of the radio frequency guide rod and is disposed between the liftable lower electrode assembly and the bottom wall of the vacuum reaction chamber, dividing the vacuum reaction chamber into a vacuum side and an atmospheric side;

[0009] The shielded transmission assembly, made of metal, is used to move the liftable lower electrode assembly. It includes: a transmission rod, the top end of which is fixedly connected to the liftable lower electrode assembly; a flange, which is seamlessly fitted onto the transmission rod; and a retractable shielding component, which is arranged circumferentially around the transmission rod, with its top end electrically connected to the flange and its bottom end electrically connected to the radio frequency shielding substrate.

[0010] Preferably, the shielding transmission assembly further includes a chassis, which is fixedly connected to the bottom end of the retractable shielding component, and the retractable shielding component is electrically connected to the radio frequency shielding substrate through the chassis to form a radio frequency circuit.

[0011] Preferably, a metal elastic element is provided between the chassis and the radio frequency shielding substrate to increase the electrical contact area.

[0012] Preferably, multiple shielded transmission components are provided, and each shielded transmission component is evenly arranged along the circumference of the radio frequency guide rod.

[0013] Preferably, the flange and the transmission rod are integrally formed.

[0014] Preferably, the transmission rod, flange, and retractable shield are made of one or more of stainless steel, aluminum, or copper.

[0015] Preferably, the retractable shielding component comprises a corrugated pipe.

[0016] Preferably, the metal elastic element includes a beryllium copper spring washer.

[0017] Preferably, the plasma processing apparatus further includes: an upper electrode assembly disposed opposite to the liftable lower electrode assembly; an RF matching device disposed below the RF shielding substrate, having an RF transmitting end and an RF receiving end of an RF circuit; the RF receiving end of the RF matching device being electrically connected to the RF shielding substrate; and the bottom end of the RF guide rod being electrically connected to the RF transmitting end of the RF matching device and connected to the upper surface of the RF matching device via a retractable connector.

[0018] Preferably, the liftable lower electrode assembly includes a movable grounding ring disposed at its bottom, the movable grounding ring being connected to the top end of the transmission rod, forming part of an radio frequency loop between the movable grounding ring and the radio frequency shielding substrate.

[0019] Preferably, the plasma processing device further includes: a fixed grounding ring, the upper part of which is arranged around the liftable lower electrode assembly, the lower part of which is located below the liftable lower electrode assembly, and the top end of which is electrically connected to the side wall of the vacuum reaction chamber, and the bottom end of which is electrically connected to the bottom wall of the vacuum reaction chamber.

[0020] Preferably, one end of the retractable seal is connected to the bottom of the movable grounding ring, and the other end is connected to the lower part of the fixed grounding ring.

[0021] Preferably, the radio frequency (RF) circuit of the plasma processing device is as follows: the RF current output from the RF transmitter of the RF matching device enters the liftable lower electrode assembly via the RF guide rod, enters the upper electrode assembly via the plasma between the upper electrode assembly and the liftable lower electrode assembly, and then sequentially passes through the side wall of the vacuum reaction chamber, the inner side of the fixed grounding ring, the outer side of the retractable sealing assembly, the outer side of the movable grounding ring, the inner side of the movable grounding ring, the surface of the transmission rod, the surface of the flange, the surface of the retractable shield, and the RF shielding substrate to the RF receiver of the RF matching device.

[0022] Preferably, a plasma confinement ring is provided between the fixed grounding ring and the side wall of the vacuum reaction chamber. The inner side of the bottom end of the plasma confinement ring is connected to the top end of the fixed grounding ring, and the outer side of its bottom end is connected to the side wall of the vacuum reaction chamber, forming an exhaust area below the bottom end of the plasma confinement ring.

[0023] Preferably, the radio frequency (RF) circuit of the plasma processing device is as follows: the RF current output from the RF transmitter of the RF matching device enters the liftable lower electrode assembly via the RF guide rod, enters the upper electrode assembly via the plasma between the upper electrode assembly and the liftable lower electrode assembly, and then sequentially passes through the side wall of the vacuum reaction chamber, the bottom end of the plasma confinement ring, the inner side of the fixed grounding ring, the outer side of the retractable sealing assembly, the outer side of the movable grounding ring, the inner side of the movable grounding ring, the surface of the transmission rod, the surface of the flange, the surface of the retractable shield, and the RF shielding substrate to the RF receiver of the RF matching device.

[0024] Preferably, the bottom wall of the vacuum reaction chamber is provided with a substrate mounting part, and the radio frequency shielding substrate is installed in the substrate mounting part, so that it is movably connected to the bottom wall of the vacuum reaction chamber.

[0025] Preferably, the inner wall of the substrate mounting portion extends into a protrusion, and the edge of the RF shielding substrate is fixed to the protrusion by a detachable connector.

[0026] Preferably, a first mounting through hole is provided at the center of the RF shielding substrate, and the RF guide rod passes through the first mounting through hole to electrically connect the liftable lower electrode assembly to the RF matching device.

[0027] Preferably, the radio frequency shielding substrate has a plurality of second mounting through holes, the position of each second mounting through hole corresponds to the position of each shielding transmission component, each transmission rod passes through the corresponding second mounting through hole, and its bottom end is connected to the servo system.

[0028] In summary, compared with the prior art, the plasma processing device provided by the present invention has the following beneficial effects:

[0029] By incorporating a shielded transmission assembly made of metallic materials, which possesses high tensile strength and high thread hardness, the service life of the transmission assembly is extended. This also effectively prevents the transmission of radio frequency (RF) current generated by RF conductor coupling along the transmission rod to the servo system. Specifically, the flange effectively prevents the flow of RF current coupled to the transmission rod. Simultaneously, a retractable shield is positioned circumferentially along the transmission rod, with its two ends connected to the bottom of the flange and the top of the RF shielding substrate, respectively. This allows the RF current to flow along the surface of the retractable shield to the RF shielding substrate, achieving RF shielding of the transmission rod.

[0030] Furthermore, by setting a chassis at the bottom of the retractable shield and a metal elastic element between the chassis and the RF shielding substrate, the electrical contact area and conductivity between the retractable shield and the RF shielding substrate are increased, enhancing RF shielding. Simultaneously, the integrated flange and transmission rod effectively prevent RF current leakage, ensuring that the RF current can only be transmitted to the RF shielding substrate through the flange surface and the retractable shield surface, and then flows back to the RF receiver of the RF matching unit, thus achieving RF shielding.

[0031] Furthermore, the RF shielding substrate is movably connected to the lower surface of the bottom wall of the vacuum reaction chamber, which facilitates the removal and replacement of the RF shielding substrate from the bottom of the vacuum reaction chamber. This avoids particulate contamination of the vacuum reaction chamber caused by replacing the RF shielding substrate from the inside of the vacuum reaction chamber, which not only improves the replacement efficiency but also ensures the cleanliness of the vacuum reaction chamber, thus improving the uniformity of wafer etching. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the plasma processing apparatus of the present invention;

[0033] Figure 2 This is a schematic diagram of the shielded transmission assembly in the plasma processing device of the present invention;

[0034] Figure 3 This is a side view of the connection structure between the bottom wall of a vacuum reaction chamber and a radio frequency shielding substrate in the plasma processing device of the present invention.

[0035] Figure 4This is a top view of the connection structure between the bottom wall of a vacuum reaction chamber and a radio frequency shielding substrate in the plasma processing device of the present invention. Detailed Implementation

[0036] The following will be combined with the appendix in the embodiments of the present invention. Figure 1 ~Attached Figure 4 The technical solutions, structural features, objectives and effects achieved in the embodiments of the present invention will be described in detail.

[0037] 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.

[0038] 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.

[0039] This invention provides a plasma processing apparatus, such as... Figure 1As shown, the plasma processing device includes a vacuum reaction chamber 100, which consists of a top cover at the top and a vacuum reaction chamber body located below the top cover. The vacuum reaction chamber body includes a vacuum reaction chamber sidewall 101 and a vacuum reaction chamber bottom wall 102. A wafer transfer port (not shown) is provided on the vacuum reaction chamber sidewall 101 for transferring wafers between the inside and outside of the vacuum reaction chamber 100. A liftable lower electrode assembly 110 is provided inside the vacuum reaction chamber 100, which is located at the bottom of the vacuum reaction chamber 100. The liftable lower electrode assembly 100 includes a base 111, and a support portion is provided on the upper surface of the base 111 for supporting the wafers transferred to the vacuum reaction chamber 100. The vacuum reaction chamber 100 also includes an upper electrode assembly 120 disposed opposite to the liftable lower electrode assembly 110. The upper electrode assembly 120 includes a gas spraying device connected to a gas supply device. Process gas from the gas supply device enters the vacuum reaction chamber 100 through the gas spraying device to perform the process in the reaction area formed between the liftable lower electrode assembly 110 and the upper electrode assembly 120. An RF shielding substrate 103 is disposed on the bottom wall 102 of the vacuum reaction chamber, and an RF matching unit 130 is disposed below it. The RF matching unit 130 applies RF power to the liftable lower electrode assembly 110. By grounding or applying RF power to the upper electrode assembly 120, the process gas is dissociated into plasma, which fills the reaction area between the upper and lower electrodes, thereby achieving the etching process on the wafer.

[0040] The RF matching unit 130 has an RF transmitter and an RF receiver forming an RF loop. The RF transmitter is used to transmit energy from the RF power supply into the vacuum reactor to form an RF current 200, and the RF receiver forms the other end of the path for the RF current 200. In this embodiment, as... Figure 1 As shown, the RF matching device 130 is fixed to the bottom of the RF shielding substrate 103, and its RF receiving end is electrically connected to the RF shielding substrate 103. Further, the RF matching device 130 is also provided with an RF guide rod 131. The top end of the RF guide rod 131 is electrically connected to the lower part of the liftable lower electrode assembly 110, and the bottom end is electrically connected to the RF transmitting end of the RF matching device 130. It is also connected to the upper surface of the RF matching device 130 via a retractable connector 132. Optionally, the retractable connector 132 includes a first bellows.

[0041] In this embodiment, a retractable sealing assembly 180 is provided between the liftable lower electrode assembly 110 and the bottom wall 102 of the vacuum reaction chamber. The retractable sealing assembly 180 extends and retracts along the axial direction of the radio frequency guide rod 131 and divides the vacuum reaction chamber 100 into a vacuum side and an atmospheric side.

[0042] To enable the vertical movement of the liftable lower electrode assembly 110, a transmission assembly is also provided below the liftable lower electrode assembly 110 to drive the liftable lower electrode assembly 110 to move vertically along the axial direction of the RF guide rod 131. In the prior art, plastic transmission assemblies are made of plastic material. However, due to the low tensile strength and low thread hardness of plastic material, its wear resistance is poor. After a period of use, the plastic transmission assembly wears out severely, requiring downtime for replacement, which leads to a reduction in production efficiency. Therefore, in other prior art, metal transmission assemblies are made of metal material. However, since metal transmission assemblies do not have RF shielding, the RF current transmitted by the RF guide rod will couple horizontally to the metal transmission assembly, causing abnormal impedance and affecting the etching rate. At the same time, RF current will be generated on the metal transmission assembly, which will be transmitted to the servo system along the metal transmission assembly, causing damage to the servo system.

[0043] In response to the above problems, such as Figure 1 and Figure 2 As shown, the plasma processing apparatus of the present invention further includes a shielded transmission assembly 190 made of metal, which is disposed on the atmospheric side of the vacuum reaction chamber 100 and is used to drive the movement of the liftable lower electrode assembly 110. The assembly includes: a transmission rod 191, the top end of which is fixedly connected to the liftable lower electrode assembly 110; a flange 192, which is seamlessly fitted onto the transmission rod 191, eliminating gaps at the connection between the transmission rod 191 and the flange 192; and a retractable shielding member 193, which is circumferentially arranged around the transmission rod 191, with its top end electrically connected to the flange 192 and its bottom end electrically connected to the radio frequency shielding substrate 103, forming a radio frequency loop between the liftable lower electrode assembly 110 and the radio frequency shielding substrate 103, so that when radio frequency propagates from top to bottom on the transmission rod 191, it does not pass through the surface of the transmission rod 191 below the flange 192, thereby achieving radio frequency shielding.

[0044] In this embodiment, the liftable lower electrode assembly 110 further includes an insulating ring 140 and a movable grounding ring 150. The insulating ring 140 is disposed around the base 111, and the movable grounding ring 150 is disposed at the bottom of the liftable lower electrode assembly 110. Specifically, the movable grounding ring 150 is fixedly disposed around the outside of the insulating ring 140. The insulating ring 140 is made of an insulating material, such as ceramic, to electrically isolate the base 111 and the movable grounding ring 150. The movable grounding ring 150 is made of a conductive material and serves as part of the radio frequency circuit. Furthermore, the top end of the transmission rod 191 is connected to the bottom end of the movable grounding ring 150. Since the flange 192 is seamlessly fitted onto the transmission rod 191, the transmission rod 191 electrically connects the movable grounding ring 150 and the flange 192. At the same time, the retractable shield 193 electrically connects the flange 192 and the radio frequency shielding substrate 103, thereby forming the radio frequency circuit between the movable grounding ring 150 and the radio frequency shielding substrate 103 to achieve radio frequency shielding and prevent radio frequency from leaking out of the cavity by propagating downwards through the transmission rod 191.

[0045] In this embodiment, a fixed grounding ring 160 is also provided inside the vacuum reaction chamber 100. The upper part of the fixed grounding ring 160 surrounds the liftable lower electrode assembly 110, and the lower part is located below the liftable lower electrode assembly 110. The top end is electrically connected to the side wall 101 of the vacuum reaction chamber, and the bottom end is electrically connected to the bottom wall 102 of the vacuum reaction chamber. The fixed grounding ring 160 is made of conductive material and also serves as part of the radio frequency (RF) circuit. There is a gap between the fixed grounding ring 160 and the movable grounding ring 150. The movable grounding ring 150 is used to form a stable RF circuit between the fixed grounding ring 160 and the grounding terminal, i.e., the receiving terminal of the RF matching device, reducing RF circuit fluctuations caused by the movement of the liftable lower electrode assembly 110, thereby improving etching stability. At this time, the radio frequency circuit of the plasma processing device includes: a first part consisting of a radio frequency guide rod 131 connected to the radio frequency transmitter of the radio frequency matching unit 130 and electrically connected thereto, a liftable lower electrode assembly 110 electrically connected to the radio frequency guide rod 131, an upper electrode assembly 120 electrically connected to the liftable lower electrode assembly 110 via charged plasma, and a vacuum reaction chamber sidewall 101 electrically connected to the upper electrode assembly 120; and a fixed grounding ring 160 inner side electrically connected to the vacuum reaction chamber sidewall 101, and a fixed grounding ring 160 electrically connected to the fixed grounding ring 160. The second part comprises the outer side of the retractable sealing assembly 180, the outer side and the inner side of the movable grounding ring 150 electrically connected to the retractable sealing assembly 180; and the third part comprises the surface of the transmission rod 191 electrically connected to the movable grounding ring 150, the surface of the flange 192 electrically connected to the transmission rod 191, the surface of the retractable shield 193 electrically connected to the flange 192, the RF shielding substrate 103 electrically connected to the retractable shield 193, and the RF receiving end of the RF matching device 130 electrically connected to the RF shielding substrate 103.

[0046] Since the direction of the radio frequency current in the radio frequency circuit is determined by the potential difference between the two ends of the radio frequency circuit, the radio frequency current flows from the end with high potential to the end with low potential. Therefore, when the potential of the output end of the radio frequency matching device 130 is greater than 0 and its receiving end is grounded (i.e., the receiving end is at 0 potential), the radio frequency transmitting end of the radio frequency matching device 130 transmits the energy of the radio frequency power supply into the vacuum reaction chamber to form a radio frequency current 200. This current enters the liftable lower electrode assembly 110 through the radio frequency guide rod 131, enters the upper electrode assembly 120 through the plasma between the upper electrode assembly 120 and the liftable lower electrode assembly 110, and then flows sequentially through the side wall 101 of the vacuum reaction chamber, the inner side of the fixed grounding ring 160, the outer side of the retractable sealing assembly 180, the outer side of the movable grounding ring 150, the inner side of the movable grounding ring 150, the surface of the transmission rod 191, the surface of the flange 192, the surface of the retractable shield 193, and the radio frequency shielding substrate 103 to the radio frequency receiving end of the radio frequency matching device 130. Conversely, when the potential at the output of the RF matching unit 130 is less than 0 and its receiving end is grounded (i.e., the receiving end 0 is at potential), the potential at the receiving end of the RF matching unit 130 is greater than the potential at its output end (i.e., the receiving end is at a high potential). Therefore, the flow direction of the RF current 200 in the RF circuit is opposite to the flow direction of the RF current 200 mentioned above.

[0047] The retractable seal 180 includes a second bellows, both ends of which are fixed by flange assemblies. One end is connected to the bottom end of the movable grounding ring 150, and the other end is connected to the bottom end of the fixed grounding ring 160. Figure 1 As shown, the vacuum side separated by the retractable sealing member 180 is formed by the side wall of the fixed grounding ring 160, the inner wall of the retractable sealing member 180, the side wall of the movable grounding ring 150, the side wall 101 of the vacuum reaction chamber, and the top cover. The upper surface of the liftable lower electrode assembly 110 is sealed on the vacuum side of the vacuum reaction chamber 100 for etching processes. The lower surface of the liftable lower electrode assembly 110 and the radio frequency guide rod 131 are located on the atmospheric side of the vacuum reaction chamber 100.

[0048] Furthermore, a plasma confinement ring 170 is provided between the fixed grounding ring 160 and the sidewall 101 of the vacuum reaction chamber. The inner side of the bottom end of the plasma confinement ring 170 is connected to the top end of the fixed grounding ring 160, and the outer side of the bottom end is connected to the sidewall 101 of the vacuum reaction chamber, forming an exhaust area below the bottom end of the plasma confinement ring 170. The plasma confinement ring 170 confines the plasma within the reaction area between the upper electrode assembly 120 and the liftable lower electrode assembly 110 to prevent plasma leakage into the non-reaction area and damage to the components in the non-reaction area. The exhaust area is connected to an external vacuum pump to filter the process waste gas generated after the etching reaction during the process and extract it from the reaction chamber.

[0049] At this time, the radio frequency circuit of the plasma processing device includes: a first part consisting of a radio frequency conductor 131 connected to the radio frequency transmitter of the radio frequency matching unit 130 and electrically connected thereto, a liftable lower electrode assembly 110 electrically connected to the radio frequency conductor 131, an upper electrode assembly 120 electrically connected to the liftable lower electrode assembly 110 via charged plasma, and a vacuum reaction chamber sidewall 101 electrically connected to the upper electrode assembly 120; and a fixed grounding ring 160 consisting of the bottom end of the plasma confinement ring 170 electrically connected to the vacuum reaction chamber sidewall 101 and the inner end of the plasma confinement ring 170 electrically connected to the plasma confinement ring 170. The second part comprises the outer side of the retractable sealing assembly 180 electrically connected to the fixed grounding ring 160, the outer side and inner side of the movable grounding ring 150 electrically connected to the retractable sealing assembly 180; and the third part comprises the surface of the transmission rod 191 electrically connected to the movable grounding ring 150, the surface of the flange 192 electrically connected to the transmission rod 191, the surface of the retractable shield 193 electrically connected to the flange 192, the RF shielding substrate 103 electrically connected to the retractable shield 193, and the RF receiving end of the RF matching device 130 electrically connected to the RF shielding substrate 103.

[0050] Similarly, when the output potential of the RF matching unit 130 is greater than 0 and its receiving end is grounded (i.e., the receiving end is at 0 potential), the RF transmitting end of the RF matching unit 130 transmits the energy of the RF power supply into the RF current 200 formed inside the vacuum reaction chamber. This current enters the liftable lower electrode assembly 110 through the RF guide rod 131, enters the upper electrode assembly 120 through the plasma between the upper electrode assembly 120 and the liftable lower electrode assembly 110, and then flows sequentially through the side wall 101 of the vacuum reaction chamber, the bottom end of the plasma confinement ring 170, the inner side of the fixed grounding ring 160, the outer side of the retractable sealing assembly 180, the outer side of the movable grounding ring 150, the inner side of the movable grounding ring 150, the surface of the transmission rod 191, the surface of the flange 192, the surface of the retractable shield 193, and the RF shielding substrate 103 to the RF receiving end of the RF matching unit 130. Conversely, when the potential at the output of the RF matching unit 130 is less than 0 and its receiving end is grounded (i.e., the receiving end 0 is at potential), the potential at the receiving end of the RF matching unit 130 is greater than the potential at its output end (i.e., the receiving end is at a high potential). Therefore, the flow direction of the RF current 200 in the RF circuit is opposite to the flow direction of the RF current 200 mentioned above.

[0051] In this embodiment, as Figure 1 As shown, the plasma processing apparatus is equipped with two shielded transmission assemblies 190, which are symmetrically arranged on both sides of the radio frequency guide rod 131. In other embodiments, the number of shielded transmission assemblies 190 is greater than two. These shielded transmission assemblies are uniformly arranged along the circumference of the radio frequency guide rod 131 to provide uniform thrust, keeping the upper surface of the liftable lower electrode assembly 110 horizontal during movement. Simultaneously, this allows for a symmetrical distribution of the radio frequency circuits in the plasma processing apparatus, helping to create a uniform radio frequency field on the vacuum side of the vacuum reaction chamber 100. This, in turn, dissociates the process gas to form a uniform plasma reaction field, resulting in more uniform wafer etching and improved wafer processing yield. Furthermore, combined with... Figure 1 , Figure 3 and Figure 4 The RF shielding substrate 103 has multiple second mounting through holes 1032, the positions of which correspond to the positions of the shielding transmission components 190. Each transmission rod 191 passes through the corresponding second mounting through hole 1032 and is connected to a servo system (not shown in the figure) at its bottom. The servo system provides driving force to each transmission rod 191, causing the transmission rod 191 to move up and down in the vertical direction, thereby driving the liftable lower electrode assembly 110 to move up and down, thus changing the spacing between the upper and lower electrodes and realizing dynamic adjustment of the etching rate at the wafer edge.

[0052] In another embodiment, the transmission rod 191 is a closed ring extending vertically around the radio frequency guide rod. The top end of the transmission rod 191 is connected to the movable grounding ring 150. Correspondingly, the radio frequency shielding substrate 103 is provided with a mounting ring hole that matches the transmission rod 191. The bottom end of the transmission rod 191 passes through the mounting ring hole and is connected to the servo system. The servo system controls the transmission rod 191 to move up and down along the axial direction of the radio frequency guide rod 131, thereby driving the liftable lower electrode 110 to move up and down. Similarly, flange rings (including an inner flange ring and an outer flange ring) are seamlessly welded to the inner and outer walls of the transmission rod 191. An inner retractable shielding component and an outer retractable shielding component are respectively arranged around the inner and outer walls of the transmission rod 191. The top and bottom ends of the inner retractable shielding component are connected to the inner flange ring and the radio frequency shielding substrate 103, respectively. The top and bottom ends of the outer retractable shielding component are connected to the outer flange ring and the radio frequency shielding substrate 103, respectively, so as to achieve radio frequency shielding of the transmission rod 191.

[0053] Optionally, the transmission rod 191, flange 192, and retractable shield 193 in the shielded transmission assembly 190 are made of stainless steel, but they can also be made of other metal materials, such as aluminum or copper. In this embodiment, the retractable shield 193 comprises a third corrugated tube made of stainless steel, which has high mechanical toughness and a large telescopic stroke. It is not easily damaged even after repeated folding and expansion, eliminating the need for frequent replacement and reducing equipment maintenance costs.

[0054] In another embodiment, such as Figure 2 As shown, the shielded transmission assembly 190 also includes a chassis 194, which is fixedly connected to the bottom end of the retractable shield 193. The retractable shield 193 is electrically connected to the RF shielding substrate 103 through the chassis 194 to form an RF circuit. Specifically, the top end of the retractable shield 193 is seamlessly welded to the flange 192, and the bottom end is seamlessly welded to the chassis 194. The chassis 194 has a third threaded hole 195 for fixing the chassis 194 to the RF shielding substrate 103 to form an electrical connection, thus forming effective RF shielding. Furthermore, a metal elastic element 196 is provided between the chassis 194 and the RF shielding substrate 103. When the chassis 194 compresses the metal elastic element 196, the metal elastic element 196 deforms, increasing the electrical contact area between the chassis 194 and the RF shielding substrate 103, enhancing RF shielding, helping to improve the service life of the transmission rod 194, and reducing the wear and tear on materials and manpower.

[0055] Optionally, the flange 192 and the transmission rod 191 are integrally formed, avoiding the defect of possible gaps between the flange 192 and the transmission rod 191. If there is a gap between the flange 192 and the transmission rod 191, the radio frequency current 200 will leak from the gap and flow along the transmission rod 191 to the servo system connected to its bottom end, causing damage to the servo system. In this embodiment, the metal elastic element 196 includes a beryllium copper spring washer, which has advantages such as strong deformation capability, good conductivity, and long service life. It not only increases the electrical contact area between the chassis 194 and the radio frequency shielding substrate 103, but also improves the conductivity between the two, resulting in a better radio frequency shielding effect.

[0056] Furthermore, in this embodiment, the radio frequency shielding substrate 103 has a first mounting through hole 1031 (e.g., ...) at its center. Figure 3 and Figure 4 As shown, the RF guide rod 131 passes through the first mounting through hole 1031 to electrically connect the liftable lower electrode assembly 110 to the RF matching device 130. The top end of the RF guide rod 131 is fixedly connected to the lower surface of the base 111 in the liftable lower electrode assembly 110. The RF matching device 130 adjusts its impedance according to different RF frequencies applied by the RF power supply, so that the RF power can be coupled to the liftable lower electrode assembly 110 to the maximum extent. Due to the presence of the retractable connector 132, the liftable lower electrode assembly 110 can move up and down with the RF guide rod 131 while maintaining the fixed connection between the RF matching device 130 and the RF shielding substrate 103, avoiding the adverse effects of unstable RF power.

[0057] Of course, the arrangement of the RF matching unit 130 is not limited to the above. The number of RF matching units 130 can be one or more, and multiple RF matching units 130 can have different RF frequencies and powers. In some embodiments, the liftable lower electrode assembly 110 can be connected to one or more RF matching units 130, for example, two RF matching units 130. In embodiments connecting multiple RF matching units 130, each RF matching unit 130 can provide a different RF frequency and power than the others to suit the needs of different processing technologies. In these embodiments, the upper electrode assembly 120 can be grounded. In other embodiments, the liftable lower electrode assembly 110 can be connected to one RF matching unit 130, and the upper electrode assembly 120 can be connected to another RF matching unit 130. These two RF matching units 130 can provide different RF frequencies and powers to meet process requirements. When multiple RF matching units 130 are provided, the RF matching units 130 are disposed below the RF shielding substrate 103, so that the RF receiving end of each RF matching unit 130 is electrically connected to the RF shielding substrate 103. Optionally, a plurality of the radio frequency matching units 130 are arranged circumferentially along the bottom of the radio frequency shielding substrate 103.

[0058] Furthermore, such as Figure 3 and Figure 4 As shown, a substrate mounting portion 121 is provided on the bottom wall 102 of the vacuum reaction chamber for mounting the radio frequency shielding substrate 103 on the substrate mounting portion 121, so that it is movably connected to the bottom wall 102 of the vacuum reaction chamber. In this embodiment, the substrate mounting portion 121 is part of the bottom wall 102 of the reaction chamber, and a protrusion extends from its inner wall. The edge of the radio frequency shielding substrate 103 is fixed to the protrusion by a detachable connector. In other embodiments, the substrate mounting portion 121 can also be an independent structure fixedly connected to the bottom wall 102 of the reaction chamber. Specifically, the lower surface of the protrusion is provided with a plurality of first threaded holes, and the edge of the radio frequency shielding substrate 103 is provided with a plurality of second threaded holes that match each of the first threaded holes. Screws are passed through each of the second threaded holes and fixed in each of the first threaded holes of the protrusion, thereby fixing the radio frequency shielding substrate 103 to the lower surface of the bottom wall 102 of the vacuum reaction chamber. When disassembling and replacing the RF shielding substrate 103, the screws are unscrewed sequentially from the first threaded hole and the second threaded hole, causing the RF shielding substrate 103 to separate from the lower surface of the bottom wall 102 of the vacuum reaction chamber. Optionally, in other embodiments, a snap-fit ​​is used as the detachable connector to movably connect the RF shielding substrate 103 to the substrate mounting portion 121.

[0059] In summary, the plasma processing apparatus of the present invention, by incorporating a shielded transmission assembly 190 made of metallic material, possesses high tensile strength and high thread hardness, which not only extends the service life of the transmission assembly but also effectively avoids the defect of radio frequency current generated by coupling on the transmission rod 191 to the servo system. Specifically, the flange 192 effectively prevents the flow of radio frequency coupled on the transmission rod 191 along the transmission rod 191, while the retractable shield 193 is arranged circumferentially along the transmission rod 191, with its two ends connected to the bottom of the flange 192 and the top of the radio frequency shielding substrate 103, respectively, so that the radio frequency current flows along the surface of the retractable shield 193 to the radio frequency shielding substrate 103, thereby achieving radio frequency shielding of the transmission rod 191.

[0060] Furthermore, by providing a base 194 at the bottom of the retractable shield 193 and a metal elastic element 196 between the base 194 and the RF shielding substrate 103, the electrical contact area and conductivity between the retractable shield 193 and the RF shielding substrate 103 are increased, enhancing RF shielding. Simultaneously, the integrated flange 192 and transmission rod 191 effectively prevent leakage of the RF current 200, ensuring that the RF current 200 can only be transmitted to the RF shielding substrate 103 through the surface of the flange 192 and the retractable shield 193, and then flow back to the RF receiver of the RF matching unit 130, thus achieving RF shielding.

[0061] Furthermore, the RF shielding substrate 103 is movably connected to the lower surface of the bottom wall 102 of the vacuum reaction chamber, which facilitates the removal and replacement of the RF shielding substrate 103 from the bottom of the vacuum reaction chamber 100. This avoids particulate contamination of the vacuum reaction chamber 100 caused by replacing the RF shielding substrate 103 from the inside of the vacuum reaction chamber 100, which not only improves the replacement efficiency but also ensures the cleanliness of the vacuum reaction chamber 100, which is beneficial to improving the uniformity of wafer etching.

[0062] It should be noted that, in the embodiments of the present invention, the terms “center,” “longitudinal,” “lateral,” “upper,” “lower,” “vertical,” “horizontal,” “top,” “bottom,” “inner side,” “outer side,” “radial,” “circumferential,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0063] 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 a liftable lower electrode assembly inside, and a radio frequency shielding substrate is provided on the bottom wall of the vacuum reaction chamber. The top end of the radio frequency guide rod is electrically connected to the lower part of the lower electrode assembly; A retractable sealing assembly extends and retracts vertically along the axial direction of the radio frequency guide rod and is disposed between the liftable lower electrode assembly and the bottom wall of the vacuum reaction chamber, dividing the vacuum reaction chamber into a vacuum side and an atmospheric side; The shielded transmission assembly, made of metal, is used to move the liftable lower electrode assembly. It includes: a transmission rod, the top end of which is fixedly and electrically connected to the liftable lower electrode assembly; a flange, which is seamlessly fitted onto the transmission rod; and a retractable shielding component, which is arranged circumferentially around the transmission rod, with its top end electrically connected to the flange and its bottom end electrically connected to the radio frequency shielding substrate.

2. The plasma processing apparatus as described in claim 1, characterized in that, The shielding transmission assembly also includes a chassis, which is fixedly connected to the bottom end of the retractable shielding component. The retractable shielding component is electrically connected to the radio frequency shielding substrate through the chassis to form a radio frequency circuit.

3. The plasma processing apparatus as described in claim 2, characterized in that, A metal elastic element is provided between the chassis and the radio frequency shielding substrate to increase the electrical contact area.

4. The plasma processing apparatus as described in claim 1, characterized in that, Multiple shielded transmission components are provided, and each shielded transmission component is evenly arranged along the circumference of the radio frequency guide rod.

5. The plasma processing apparatus as described in claim 1, characterized in that, The flange and the transmission rod are integrally formed.

6. The plasma processing apparatus as described in claim 1, characterized in that, The transmission rod, flange, and retractable shield are made of one or more materials, such as stainless steel, aluminum, or copper.

7. The plasma processing apparatus as described in claim 1, characterized in that, The retractable shielding component includes a corrugated tube.

8. The plasma processing apparatus as described in claim 3, characterized in that, The metal elastic element includes a beryllium copper spring washer.

9. The plasma processing apparatus as claimed in claim 1, characterized in that, Also includes: An upper electrode assembly is disposed opposite to the liftable lower electrode assembly; The radio frequency matching device disposed below the radio frequency shielding substrate has a radio frequency transmitting end and a radio frequency receiving end of the radio frequency circuit; the radio frequency receiving end of the radio frequency matching device is electrically connected to the radio frequency shielding substrate. The bottom end of the RF guide rod is electrically connected to the RF transmitter of the RF matching device, and is connected to the upper surface of the RF matching device through a retractable connector.

10. The plasma processing apparatus as described in claim 9, characterized in that, The liftable lower electrode assembly includes a movable grounding ring disposed at its bottom, the movable grounding ring being connected to the top end of the transmission rod, forming part of an radio frequency circuit between the movable grounding ring and the radio frequency shielding substrate.

11. The plasma processing apparatus as claimed in claim 10, characterized in that, Also includes: A fixed grounding ring is provided, with its upper part surrounding the liftable lower electrode assembly, its lower part located below the liftable lower electrode assembly, and its top end electrically connected to the side wall of the vacuum reaction chamber and its bottom end electrically connected to the bottom wall of the vacuum reaction chamber.

12. The plasma processing apparatus as claimed in claim 11, characterized in that, One end of the retractable seal is connected to the bottom of the movable grounding ring, and the other end is connected to the lower part of the fixed grounding ring.

13. The plasma processing apparatus as described in claim 12, characterized in that, The radio frequency (RF) circuit of the plasma processing device is as follows: the RF current output from the RF transmitter of the RF matching device enters the liftable lower electrode assembly through the RF guide rod, enters the upper electrode assembly through the plasma between the upper electrode assembly and the liftable lower electrode assembly, and then sequentially passes through the side wall of the vacuum reaction chamber, the inner side of the fixed grounding ring, the outer side of the retractable sealing assembly, the outer side of the movable grounding ring, the inner side of the movable grounding ring, the surface of the transmission rod, the surface of the flange, the surface of the retractable shield, and the RF shielding substrate to the RF receiver of the RF matching device.

14. The plasma processing apparatus as claimed in claim 12, characterized in that, A plasma confinement ring is provided between the fixed grounding ring and the side wall of the vacuum reaction chamber. The inner side of the bottom end of the plasma confinement ring is connected to the top end of the fixed grounding ring, and the outer side of its bottom end is connected to the side wall of the vacuum reaction chamber. An exhaust area is formed below the bottom end of the plasma confinement ring.

15. The plasma processing apparatus as described in claim 14, characterized in that, The radio frequency (RF) circuit of the plasma processing device is as follows: the RF current output from the RF transmitter of the RF matching device enters the liftable lower electrode assembly through the RF guide rod, enters the upper electrode assembly through the plasma between the upper electrode assembly and the liftable lower electrode assembly, and then sequentially passes through the side wall of the vacuum reaction chamber, the bottom end of the plasma confinement ring, the inner side of the fixed grounding ring, the outer side of the retractable sealing assembly, the outer side of the movable grounding ring, the inner side of the movable grounding ring, the surface of the transmission rod, the surface of the flange, the surface of the retractable shield, and the RF shielding substrate to the RF receiver of the RF matching device.

16. The plasma processing apparatus as claimed in claim 1, characterized in that, The bottom wall of the vacuum reaction chamber is provided with a substrate mounting part, and the radio frequency shielding substrate is installed in the substrate mounting part, so that it is movably connected to the bottom wall of the vacuum reaction chamber.

17. The plasma processing apparatus as claimed in claim 16, characterized in that, The inner wall of the substrate mounting portion has a protrusion, and the edge of the radio frequency shielding substrate is fixed to the protrusion by a detachable connector.

18. The plasma processing apparatus as described in claim 9, characterized in that, The radio frequency shielding substrate has a first mounting through hole at its center, and the radio frequency guide rod passes through the first mounting through hole to electrically connect the liftable lower electrode assembly to the radio frequency matching device.

19. The plasma processing apparatus as claimed in claim 4, characterized in that, The radio frequency shielding substrate has multiple second mounting through holes, the position of each second mounting through hole corresponds to the position of each shielding transmission component, each transmission rod passes through the corresponding second mounting through hole, and its bottom end is connected to the servo system.

Images