Plasma restraining device and plasma processing device thereof

Abstract

The invention discloses a plasma confinement device and a plasma processing device thereof.The plasma confinement device is arranged between the cavity side wall of a vacuum reaction cavity and a lower electrode assembly and comprises an upper confinement ring and a lower confinement ring located below the upper confinement ring; the upper restraint ring comprises a plurality of first distance pieces surrounding the lower electrode assembly, the lower restraint ring comprises a plurality of second distance pieces surrounding the lower electrode assembly, and the first distance pieces and the second distance pieces are arranged in a staggered mode. A gas channel is formed between the first spacer and the second spacer adjacent to the first spacer. The plasma confinement device has the advantages that the upper confinement rings and the lower confinement rings are combined in a staggered manner, so that enough confinement capacity on plasma is guaranteed, the blocking effect on airflow can be reduced, the conductance of a reaction cavity is improved, and collaborative optimal adjustment of various process conditions is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor equipment, and in particular to a plasma confinement device and a plasma processing device thereof. Background Art

[0002] In the manufacturing process of semiconductor devices, plasma etching, physical vapor deposition, chemical vapor deposition and other processes are often used to micro-process semiconductor process parts or wafer substrates. The micro-processing manufacturing steps may include plasma-assisted processes, which are generally carried out in a vacuum reaction chamber. Among them, the plasma etching process in the plasma-assisted process is the key process for processing the wafer into the designed pattern.

[0003] The principle of the plasma etching process in the vacuum reaction chamber is to introduce process gas into the vacuum reaction chamber, and activate the process gas above the wafer by inputting radio frequency energy to ignite and maintain plasma, thereby generating a plasma environment, and etching the wafer. Taking the CCP etching reaction chamber as an example, the excited plasma moves under the action of the electric field force on the one hand, and on the other hand, it continues to diffuse around. However, the plasma has a strong corrosive ability. If it diffuses to the non-reactive area (such as the area where some parts of the lower electrode assembly are located), it may cause corrosion or erosion of the parts in these areas, causing particle contamination or other metal contamination inside the cavity, shortening the working life of the parts, and reducing the reusability of the chamber. If the plasma is not confined to a certain working area, the charged particles will hit the unprotected area, resulting in impurities and contamination on the surface of the semiconductor wafer.

[0004] Based on the above problems, the industry usually sets a plasma confinement assembly to limit the plasma to the reaction area between the upper electrode assembly and the lower electrode assembly as much as possible to protect the components in the non-reaction area. However, with the further development of the process, higher requirements are put forward for the vacuum degree of the etching equipment, and also higher requirements are put forward for the plasma confinement capabilities of the plasma confinement assembly.

[0005] It should be understood that the above statements merely provide background technology related to the present invention and do not necessarily constitute prior art. Summary of the invention

[0006] Based on the aforementioned technical problems, the object of the present invention is to provide a plasma confinement device and a plasma processing device thereof. The plasma confinement device, through the mutual cooperation of an upper confinement ring and a lower confinement ring, can reduce the gas resistance effect on the airflow while ensuring sufficient confinement ability for the plasma, thereby improving the gas extraction efficiency, and helping to achieve the coordinated optimal adjustment of various process conditions, thereby ensuring the processing effect of the wafer.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0008] A plasma confinement device for a plasma processing device, the plasma processing device comprising a vacuum reaction chamber, wherein a lower electrode assembly is arranged in the vacuum reaction chamber,

[0009] The plasma confinement device is arranged between the chamber side wall of the vacuum reaction chamber and the lower electrode assembly, and the plasma confinement device includes an upper confinement ring and a lower confinement ring located below the upper confinement ring, the upper confinement ring includes a plurality of first spacers surrounding the lower electrode assembly, and the lower confinement ring includes a plurality of second spacers surrounding the lower electrode assembly, each of the first spacers and each of the second spacers are arranged alternately, and a gas channel is formed between the first spacers and the second spacers adjacent to them.

[0010] Optionally, the upper constraint ring and the lower constraint ring can move up and down relative to each other.

[0011] Optionally, the upper restraint ring is fixedly arranged, and the lower restraint ring is connected to a driving device so as to move up and down.

[0012] Optionally, the lower restraint ring includes a connection portion for connecting to the drive device;

[0013] The upper confinement ring is fixedly connected to the lower electrode assembly or the vacuum reaction chamber body.

[0014] Optionally, the lower restraint ring is fixedly arranged, and the upper restraint ring is connected to a driving device so as to move up and down.

[0015] Optionally, the upper restraint ring includes a connection portion for connecting to the drive device;

[0016] The lower confinement ring is fixedly connected to the lower electrode assembly or the vacuum reaction chamber body.

[0017] Optionally, there is a potential difference between the upper confinement ring and the lower confinement ring.

[0018] Optionally, the potential of the upper confinement ring is greater than the potential of the lower confinement ring;

[0019] Alternatively, the potential of the lower confinement ring is greater than the potential of the upper confinement ring.

[0020] Optionally, the upper confinement ring is connected to a bias power supply;

[0021] The lower confinement ring is connected to a bias power supply.

[0022] Optionally, an absolute value range of the potential difference between the upper confinement ring and the lower confinement ring is 0 kV to 100 kV.

[0023] Optionally, the gas channel has an aspect ratio ranging from 5 to 20.

[0024] Optionally, the height of the gas channel ranges from 40% to 100% of the height of the first spacer and / or the second spacer.

[0025] Optionally, at least some of the gas channels have equal widths;

[0026] Or, the width of at least part of the gas channel increases from the center of the lower electrode assembly toward the side wall of the cavity;

[0027] The spacings between at least some adjacent first spacers are equal;

[0028] Or, the spacing between at least some adjacent first spacers increases from the center of the lower electrode assembly toward the side wall of the cavity;

[0029] The spacings between at least some of the adjacent second spacers are equal;

[0030] Alternatively, the spacing between at least some adjacent second spacers increases from the center of the lower electrode assembly toward the side wall of the cavity.

[0031] Optionally, the width of the gas channel ranges from 0.5 mm to 5 mm.

[0032] Optionally, the plurality of first spacers are connected via a first connecting member, and the plurality of second spacers are connected via a second connecting member.

[0033] Optionally, the projection positions of the first connecting member and the second connecting member in the vertical direction correspond to each other;

[0034] The first connecting member is disposed on the top of each of the first spacers;

[0035] The second connecting member is disposed at the bottom of each of the second spacers.

[0036] Optionally, the preparation material of the first spacer includes at least one of a conductor material or a semiconductor material;

[0037] The second spacer is made of a material including at least one of a conductor material and a semiconductor material.

[0038] Optionally, a plasma corrosion resistant film layer is provided on the surface of the first spacer and / or the second spacer.

[0039] Optionally, the plasma corrosion resistant film layer includes at least one of a Teflon film layer, an yttrium oxide film layer, or an anodized layer.

[0040] Optionally, a plasma processing device comprises:

[0041] A vacuum reaction chamber, wherein a lower electrode assembly is disposed in the vacuum reaction chamber;

[0042] As mentioned above, the plasma confinement device is located in the vacuum reaction chamber.

[0043] Compared with the prior art, the technical solution of the present invention has at least the following advantages:

[0044] In a plasma confinement device and a plasma processing device thereof of the present invention, the plasma confinement device helps to alleviate / solve the obvious contradictory limitations of existing plasma confinement devices in terms of improving the flow conductance of the reaction chamber and limiting the plasma. The plasma confinement device, through the staggered arrangement of the upper confinement ring and the lower confinement ring, can reduce the obstruction to the gas flow while ensuring sufficient confinement ability for the plasma, thereby improving the flow conductance of the reaction chamber, helping to achieve the coordinated optimal adjustment of various process conditions, and thus ensuring the processing effect of the wafer.

[0045] Furthermore, the upper confinement ring and the lower confinement ring of the plasma confinement device can move up and down relative to each other. By dynamically adjusting the position of the upper confinement ring and / or the lower confinement ring, dynamic adjustment of the reaction chamber conductance and plasma confinement capability can be achieved, providing a larger adjustment window for the use of the process.

[0046] Furthermore, there is a potential difference between the upper confinement ring and the lower confinement ring of the plasma confinement device, so that an electric field is formed in the gas channel formed between the first spacer of the upper confinement ring and the second spacer of the adjacent lower confinement ring. This electric field greatly increases the confinement ability of the plasma and also helps to improve the flow conductance of the reaction chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of a plasma processing device of the present invention;

[0048] Figure 2 is a schematic diagram of a plasma confinement device of the present invention in an unassembled state;

[0049] Figure 3 A top view of a plasma confinement device of the present invention;

[0050] Figure 4 is a cross-sectional schematic diagram of a plasma confinement device of the present invention;

[0051] Figure 5 for Figure 4 The enlarged schematic diagram of point A in the middle;

[0052] Figure 6 for Figure 4 A partial schematic diagram of a plasma confinement device;

[0053] Figure 7 is a cross-sectional schematic diagram of another plasma confinement device of the present invention;

[0054] Figure 8 for Figure 7 A partial schematic diagram of the plasma confinement device. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] It should be noted that, in this article, the terms "include", "comprises", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "includes..." or "comprising..." do not exclude the existence of other elements in the process, method, article or terminal device including the elements.

[0057] It should be noted that the drawings are all in very simplified form and use inaccurate ratios, and are only used to conveniently and clearly assist in explaining the embodiments of the present invention.

[0058] like Figure 1As shown, it is a schematic diagram of a plasma processing device of the present invention, and the plasma processing device comprises: a vacuum reaction chamber 100, which is surrounded by a reaction chamber body and a chamber end cover 101, and the reaction chamber body is usually made of metal material, and comprises a chamber side wall 102 and a chamber bottom wall 103. A wafer transfer port (not shown in the figure) is provided on the chamber side wall 102, and the wafer transfer port is used to realize the transfer of wafers between the inside and outside of the vacuum reaction chamber 100. The vacuum reaction chamber 100 comprises a lower electrode assembly 110, which is arranged at the bottom of the vacuum reaction chamber 100, and the lower electrode assembly 110 is provided with a bearing surface, and the wafer to be processed introduced into the vacuum reaction chamber 100 is placed on the bearing surface. The vacuum reaction chamber 100 also comprises an upper electrode assembly 120 arranged opposite to the lower electrode assembly 110, and the space between the upper electrode assembly 120 and the lower electrode assembly 110 is a processing area for processing the wafer surface. The upper electrode assembly 120 includes a mounting substrate 121 connected to the top of the chamber and a gas shower head 122 disposed at the bottom of the mounting substrate 121. A process gas in a gas delivery device 130 is introduced into the vacuum reaction chamber 100 via the gas shower head 122 of the upper electrode assembly 120. Optionally, the upper electrode assembly 120 further includes an isolation ring 123, which surrounds the gas shower head 122 and extends downward. The isolation ring 123 is a moving ring that can move up and down, and can isolate the plasma in a specified area.

[0059] At least one RF power supply 140 applies RF energy to the lower electrode assembly 110 through a matching network, and dissociates the process gas into plasma P through capacitive coupling, so that a plasma P environment is formed between the upper electrode assembly 120 and the lower electrode assembly 110 for etching. The plasma P environment contains a large number of active particles such as electrons, ions, excited atoms, molecules and free radicals. The above-mentioned active particles can undergo various physical and / or chemical reactions with the surface of the wafer to be processed, so that the morphology of the wafer to be processed changes, thereby completing the processing of the wafer to be processed.

[0060] Furthermore, the vacuum reaction chamber 100 is provided with an exhaust port 104, specifically, the exhaust port 104 is provided on the bottom wall 103 of the chamber, and a vacuum extraction device 150 discharges the gas inside the vacuum reaction chamber 100, i.e., the reaction waste product, to the outside of the chamber through the exhaust port 104. Optionally, the vacuum extraction device 150 may be a molecular pump, a dry pump, or a vacuum pump group. Of course, the structure of the vacuum extraction device 150 is not limited thereto, and it may also be any other device that can achieve the same function.

[0061] In practical applications, the vacuum extraction device 150 is usually arranged at the bottom of the vacuum reaction chamber 100, and the plasma P is more likely to diffuse and escape in the vertical downward direction. Based on the above, the plasma processing device is also provided with a plasma confinement device 160 (Confinement Ring), which is arranged between the chamber side wall 102 and the lower electrode assembly 110 to confine the plasma P in the reaction area between the upper electrode assembly 120 and the lower electrode assembly 110. During operation, the reaction waste gas flow is drawn from the processing area through the plasma confinement device 160, the chamber space below the plasma confinement device 160, and the exhaust port 104 to be discharged outside the chamber. Some unreacted active particles contained in the reaction waste gas flow collide with each other and extinguish when passing through the plasma confinement device 160, or extinguish when contacting the plasma confinement device 160, thereby ensuring that the plasma P will not pass through the plasma confinement device 160 and leak to the non-reaction area, thereby avoiding damage to the components in the non-reaction area.

[0062] With the continuous advancement of technology nodes, the environmental pressure required for plasma P etching is getting smaller and smaller, especially in the deep hole etching process, the reaction waste gas flow needs a lower reaction chamber pressure to discharge it outside the cavity. Under the same vacuum extraction device 150, reducing the air resistance of the gas flow channel through which the gas flow passes can obtain a lower pressure environment. The plasma confinement device 160 is an important component that affects the air resistance in the gas flow channel. Changing the plasma confinement device 160 to obtain a larger area of ​​the gas flow channel size is the most effective way to improve the flow conductance. At present, it is often used to increase the width of the gas flow channel of the plasma confinement device 160 or reduce the height, that is, the length dimension of the gas flow channel to improve the flow conductance of the reaction chamber. However, when its size increases to a certain extent, the larger the size of the gas flow channel, the easier it is for the plasma P to pass through the gas flow channel and leak to the non-reactive area below the plasma confinement device 160. On the one hand, the plasma P leaking into the non-reactive area will contact the cavity side wall 102 and the parts in the area to cause corrosion of the cavity side wall 102 and the parts. On the other hand, the polymer generated by the reaction is more likely to accumulate on the cavity side wall 102 and the parts. After a period of time, the deposited polymer will peel off and cause particle pollution problems. Therefore, there is a contradiction between limiting the plasma P and increasing the gas conductance, and it is extremely important to resolve this contradiction.

[0063] Based on the above, the plasma confinement device 160 of the present invention comprises an upper confinement ring 161 and a lower confinement ring 162 located below the upper confinement ring 161 (see Figures 2 to 8), the upper confinement ring 161 includes a plurality of first spacers 163 surrounding the lower electrode assembly 110, the lower confinement ring 162 includes a plurality of second spacers 164 surrounding the lower electrode assembly 110, each of the first spacers 163 and each of the second spacers 164 are arranged alternately, and a gas channel 165 is formed between the first spacers 163 and the second spacers 164 adjacent thereto (see Figure 5 ), in actual use, the positions of the upper constraint ring 161 and the lower constraint ring 162 can be set according to actual needs.

[0064] Based on the above structure, the plasma confinement device 160 at least includes a gas channel 165 formed between the first spacer 163 and the second spacer 164 adjacent thereto. When the first spacer 163 and the second spacer 164 have a non-overlapping area in the lateral direction (see Figure 7 ), the plasma confinement device 160 further comprises a first gas flow channel 166 formed in a non-overlapping area between each adjacent first spacer 163 and a second gas flow channel 167 formed in a non-overlapping area between each adjacent second spacer 164, that is, the plasma confinement device 160 comprises a first gas flow channel 166, a second gas flow channel 167 and a gas channel 165, and the width of each channel may be different, and the flow conductance thereof to the gas flow may also be different, and the confinement ability to the plasma P may also be different. The width of the gas channel 165 is smaller than the width of the first gas flow channel 166 and the second gas flow channel 167, and generally the depth-to-width ratio of the gas channel 165 is larger than the depth-to-width ratio of the first gas flow channel 166 and the second gas flow channel 167, and the confinement ability to the plasma P is stronger. In actual use, the plasma P first enters the first airflow channel 166, part of the plasma P is annihilated in the first airflow channel 166, and the remaining plasma P enters the airflow channel 165, and then annihilates in the airflow channel 165, so as to confine the plasma P. If there is still part of the plasma P that has not been annihilated, it will collide and extinguish after entering the second airflow channel 167. In actual installation and use, the positions of the upper confinement ring 161 and the lower confinement ring 162 can be set according to actual needs, and the depth-to-width ratio and other data of each channel can be adjusted. While ensuring the confinement ability of the plasma confinement device 160 on the plasma P, the flow conduction effect on the airflow is enhanced to meet the requirements of vacuum pumping.

[0065] Furthermore, in this embodiment, the upper confinement ring 161 and the lower confinement ring 162 can move up and down relatively, that is, the relative position between the upper confinement ring 161 and the lower confinement ring 162 can be dynamically adjusted. In any state in actual application, the overlapping area range of the first spacer 163 of the upper confinement ring 161 and the second spacer 164 of the lower confinement ring 162 in the lateral direction can be adjusted, and the parameters of the first gas flow channel 166, the second gas flow channel 167 and the gas channel 165 will also change accordingly. The more the overlapping area of ​​the first spacer 163 and the second spacer 164 in the lateral direction, the higher the height L of the gas channel 165 will be, the higher the aspect ratio of the gas channel 165 will be, and the ability to restrict the plasma P will be enhanced, thereby enhancing the ability of the entire plasma confinement device 160 to restrict the plasma P, effectively preventing the plasma P from leaking to the bottom of the plasma confinement device 160, and avoiding damage and contamination of the components and the inner wall of the chamber in the non-reaction area. However, the gas channel 165 with a high aspect ratio may also increase the resistance to gas flow. The less the overlapping area between the first spacer 163 and the second spacer 164 in the lateral direction, the higher the height of the first gas flow channel 166 and the second gas flow channel 167, and the smaller the obstruction effect of the plasma confinement device 160 on the gas flow. However, the confinement ability of the first gas flow channel 166 and the second gas flow channel 167 on the plasma P is slightly weaker than that of the gas channel 165. Therefore, the range of the overlapping area between the first spacer 163 and the second spacer 164 in the lateral direction is very important. When the relative position between the upper confinement ring 161 and the lower confinement ring 162 of the plasma confinement device 160 can be dynamically adjusted, the plasma confinement device 160 can adjust the overlapping area between the first spacer 163 and the second spacer 164 in the lateral direction in real time according to actual application requirements, and change the aspect ratio of each channel, so that the plasma confinement device 160 can meet the vacuum pumping requirements while increasing its confinement ability on the plasma P. Therefore, the plasma confinement device 160 can not only confine the plasma P, but also reduce the flow resistance of the gas flow, improve the flow conductance of the reaction chamber, and achieve the coordinated optimal adjustment of various process conditions, which helps to ensure the wafer processing effect; on the other hand, the plasma confinement device 160 also helps to increase the control ability of the vacuum extraction device 150 over the vacuum degree in the vacuum reaction chamber 100.

[0066] In this embodiment, the upper restraint ring 161 is fixedly arranged, and the lower restraint ring 162 is connected to the driving device (171, 172) so that it can move up and down (see Figure 1 Specifically, the upper confinement ring 161 is fixedly connected to the components of the lower electrode assembly 110, and the lower confinement ring 162 includes a connection 1621 (see Figure 2), the driving device is connected to the connection 1621 to drive the lower confinement ring 162. In actual use, the driving device controls the lower confinement ring 162 to move up and down, so that the size parameters of the gas channel 165 formed between the first spacer 163 and the second spacer 164 adjacent thereto change, thereby adjusting the confinement ability of the plasma confinement device 160 on the plasma P and the flow guiding ability on the gas flow.

[0067] like Figure 1 As shown, in this embodiment, the driving device includes a motor 171 and a driving rod 172, and the motor 171 is connected to the connection 1621 of the lower constraint ring 162 through the driving rod 172, and the lower constraint ring 162 is driven by the motor 171 and the driving rod 172 to adjust up and down. Of course, the driving device can also be other structures that can realize corresponding driving, such as a screw drive mechanism or a cylinder, etc., and the present invention is not limited to this. It can be understood that the connection and fixing method of the upper constraint ring 161 is not limited to the above. In actual use, it can also be connected and fixed in other ways according to equipment conditions and space occupancy. For example, in another embodiment, the upper constraint ring 161 is fixedly connected to the vacuum reaction chamber 100. Further, the relative up and down movement between the upper constraint ring 161 and the lower constraint ring 162 is not limited to the above method, and it can also be realized by other methods. For example, in another embodiment, the lower constraint ring 162 is fixedly set, and the upper constraint ring 161 is connected to the driving device so as to move up and down. Further, in this embodiment, the upper confinement ring 161 includes a connection portion so as to be connected to the driving device; the lower confinement ring 162 is fixedly connected to the lower electrode assembly 110 or the body of the vacuum reaction chamber 100. For example, in another embodiment, the upper confinement ring 161 and the lower confinement ring 162 are respectively connected to the driving device, and both are movable to adjust the confinement ability and gas conductance of the plasma confinement device 160 on the plasma P. In actual applications, they can be set according to actual needs and on-site conditions.

[0068] In practical applications, the height of the gas channel 165 can be used as a reference to adjust or set the upper confinement ring 161 and the lower confinement ring 162 to meet the corresponding application requirements. Optionally, the height range of the gas channel 165 is 40% to 100% of the height of the first spacer 163 and / or the second spacer 164. Similarly, the depth-to-width ratio of the gas channel 165 can also be used as a reference to adjust or set the upper confinement ring 161 and the lower confinement ring 162. Optionally, the depth-to-width ratio of the gas channel 165 ranges from 15 to 20. Of course, the height or depth-to-width ratio of the gas channel 165 is not limited to the above range. In practical applications, it can also be other data ranges, as long as the corresponding functional effects can be achieved, and the present invention is not limited to this.

[0069] Furthermore, in order to enhance the confinement capability of the plasma confinement device 160 on the plasma P, there is a potential difference between the upper confinement ring 161 and the lower confinement ring 162, and a parallel plate capacitor structure is formed between each pair of the first spacer 163 and the second spacer 164, so that a directional electric field is generated in the gas channel 165. When the charged particles pass through the gas flow channel, they are affected by the horizontal electric field force and are accelerated to collide with the wall of the gas flow channel, accelerating their annihilation process, thereby limiting the charged particles from passing through the plasma confinement device 160. However, the electrically neutral reaction products will not be affected by the electric field force when passing through the plasma confinement device 160, and will directly pass through the gas channel 165 of the plasma confinement device 160 and be drawn out from the exhaust port 104. The electric field environment of the gas channel 165 further ensures the confinement capability of the plasma confinement device 160 on the plasma P, and at the same time, due to the existence of the electric field environment, the requirements on the depth-to-width ratio of each channel in the plasma confinement device 160 can be relaxed. For example, if conditions permit, the width of each channel can be appropriately widened to reduce the gas flow resistance and enhance the vacuum efficiency of the gas extraction device, thereby improving the gas extraction device's control accuracy of the gas pressure in the chamber. On the other hand, a first spacer 163 and a second spacer 164 with a slightly lower height can also be used to reduce the space occupied by the plasma confinement device 160, which helps to improve the space utilization rate in the chamber.

[0070] It should be noted that the present invention does not impose any restriction on the relative electric potential between the upper confinement ring 161 and the lower confinement ring 162, as long as a corresponding electric field environment can be formed at the gas channel 165. Optionally, the electric potential of the upper confinement ring 161 is greater than the electric potential of the lower confinement ring 162; or, the electric potential of the lower confinement ring 162 is greater than the electric potential of the upper confinement ring 161. In practical applications, the upper confinement ring 161 can be connected to a bias power supply, and the lower confinement ring 162 can be connected to another bias power supply, so that a potential difference is generated between the upper confinement ring 161 and the lower confinement ring 162. Of course, the upper confinement ring 161 and the lower confinement ring 162 can also be connected to the same bias power supply, and the bias power supply controls the electric potentials of the upper confinement ring 161 and the lower confinement ring 162, respectively. Figure 5 and Figure 7 As shown, in this embodiment, the upper confinement ring 161 is connected to a DC high voltage potential, and the lower confinement ring 162 is grounded.

[0071] The magnitude of the potential difference between the upper confinement ring 161 and the lower confinement ring 162 affects the magnitude of the electric field force at the gas channel 165. The magnitude of the current applied by the bias power supply to the upper confinement ring 161 and / or the lower confinement ring 162 can adjust the potential difference between the two. According to the movement principle of charged particles in an electric field, when the positions of the upper confinement ring 161 and the lower confinement ring 162 remain unchanged, the greater the potential difference between the upper confinement ring 161 and the lower confinement ring 162, the stronger the force of the electric field of the gas channel 165 on the charged particles. Optionally, the absolute value range of the potential difference between the upper confinement ring 161 and the lower confinement ring 162 is 0kV to 100kV. It can be understood that the absolute value of the potential difference between the upper confinement ring 161 and the lower confinement ring 162 is not limited to the above data range. In other embodiments, it can also be other data ranges, as long as the corresponding functional effects can be achieved, and the present invention is not limited to this. On the other hand, the force exerted by the electric field of gas channel 165 on charged particles can be adjusted by moving upper confinement ring 161 and lower confinement ring 162 up and down relative to each other, thereby changing the plate area of ​​the parallel plate capacitor structure formed in gas channel 165. In actual applications, it can be adjusted according to needs and conditions.

[0072] On the other hand, in the present invention, there is no restriction on parameters such as the spacing between adjacent first spacers 163 and the spacing between adjacent second spacers 164, and there is no restriction on the width of the gas channel 165. Optionally, the spacing between at least some adjacent first spacers 163 is equal; the spacing between at least some adjacent second spacers 164 is equal; the width of at least some of the gas channels 165 is equal. For example, in this embodiment, the distances between all adjacent first spacers 163 of the upper confinement ring 161 are equal, the distances between all adjacent second spacers 164 of the lower confinement ring 162 are equal, and the widths of the gas channels 165 are equal, that is, the upper confinement ring 161 and the lower confinement ring 162 form gas flow channels with equal spacing, which helps the gas extraction device to balance the gas pressure in the cavity, thereby improving its control accuracy. Optionally, the width of the gas channel 165 ranges from 0.5 mm to 5 mm. Of course, the width of the gas channel 165 can also be other values. The present invention does not limit this and can be set according to actual needs.

[0073] In practical applications, the spacing between adjacent first spacers 163 or second spacers 164 and the width of each gas channel 165 may also be different. In an actual process environment, most of the process gas entering the vacuum reaction chamber 100 through the gas shower head 122 is diffused and distributed in the area above the wafer. Correspondingly, after the process gas is activated into plasma P, most of the plasma P is located in the reaction area between the upper electrode assembly 120 and the lower electrode assembly 110. Part of the plasma P diffuses from the reaction area to the cavity sidewall 102. The closer to the cavity sidewall 102, the concentration of the plasma P gradually decreases, and the constraint requirement for the plasma P is smaller. Optionally, the spacing between at least some adjacent first spacers 163 increases from the center of the lower electrode assembly 110 to the cavity sidewall 102; the spacing between at least some adjacent second spacers 164 increases from the center of the lower electrode assembly 110 to the cavity sidewall 102; the width of at least some of the gas channels 165 increases from the center of the lower electrode assembly 110 to the cavity sidewall 102. That is, the width of the first gas flow channel 166, the second gas flow channel 167 and the gas channel 165 near the cavity side wall 102 is greater than the width of the first gas flow channel 166, the second gas flow channel 167 and the gas channel 165 near the lower electrode assembly 110, while achieving the confinement of the plasma P, the gas flow path is increased, and the control ability of the vacuum extraction device 150 on the vacuum degree in the cavity is guaranteed. In practical applications, a suitable solution can be selected according to actual application requirements. For example, in a certain embodiment, the width of the gas channel 165 near the cavity side wall 102 is twice the width of the gas channel 165 near the lower electrode assembly 110, and the plasma confinement device 160 can still well limit the diffusion of the plasma P and annihilate the charged particles in the plasma P. Under this condition, it also greatly enhances the control ability of the vacuum extraction device 150 on the vacuum degree in the vacuum reaction chamber 100.

[0074] like Figure 2 , Figure 5 and Figure 7 As shown ( Figure 5 and Figure 7 For along Figure 2 The upper constraint ring 161 is a cross-sectional schematic diagram cut along the middle section line B direction), the plurality of first spacers 163 of the upper constraint ring 161 are connected by a first connecting member 168, and the plurality of second spacers 164 of the lower constraint ring 162 are connected by a second connecting member 169, that is, the upper constraint ring 161 and the lower constraint ring 162 are each an integral structure, so as to facilitate the installation and use of the upper constraint ring 161 and the lower constraint ring 162. Specifically, in this embodiment, the first connecting member 168 is arranged at the top of each of the first spacers 163 ( Figure 2The second connecting member 169 is provided at the bottom of each of the second spacers 164, and the second connecting member 169 is connected to the driving rod 172 of the driving device through the connection 1621. The second connecting member 169 is driven to move up and down by the action of the motor 171 and the driving rod 172, so as to achieve the up and down adjustment of the lower confinement ring 162. Further, as shown in the figure, in this embodiment, the projection positions of the first connecting member 168 and the second connecting member 169 in the vertical direction correspond to each other, that is, the positions of the first connecting member 168 and the second connecting member 169 correspond to each other, so as to reduce the obstruction of the plasma confinement device 160 to the gas flow, thereby increasing the cross-sectional area of ​​gas flow.

[0075] Optionally, the material of the first spacer 163 includes at least one of a conductor material or a semiconductor material; the material of the second spacer 164 includes at least one of a conductor material or a semiconductor material, which can be set according to actual needs. For example, in this embodiment, a potential difference needs to be generated between the upper confinement ring 161 and the lower confinement ring 162, and the first spacer 163, the first connector 168, the second spacer 164 and the second connector 169 are all made of a conductor material (such as aluminum) to achieve current conduction, thereby generating an electric field environment at the gas channel 165 that can affect charged particles.

[0076] In order to further protect the plasma confinement device 160, in the present embodiment, the surfaces of the first spacer 163 and the second spacer 164 are both provided with a plasma P corrosion resistant film layer. Optionally, the plasma P corrosion resistant film layer includes at least one of a Teflon film layer, an yttrium oxide film layer, or an anodized layer. Of course, in practical applications, the plasma P corrosion resistant film layer may also include other materials, and the present invention does not recommend any limitation on this, as long as the first spacer 163 and the second spacer 164 can be protected from corrosion. Furthermore, the plasma P corrosion resistant film layer is not limited to being provided on the surfaces of the first spacer 163 and the second spacer 164. In other embodiments, a plasma P corrosion resistant film layer is also provided on the surfaces of the first connector 168 and / or the second connector 169, that is, the present invention does not limit the location of the plasma P corrosion resistant film layer, and it can be provided according to actual needs.

[0077] It should be noted that the plasma confinement device 160 in the present invention is not limited to the above-mentioned plasma processing device, but is also applicable to other types of plasma processing devices, such as an inductively coupled plasma processing device (ICP), etc., and the present invention is not limited to this.

[0078] In summary, in a plasma confinement device 160 and a plasma processing device thereof of the present invention, the plasma confinement device 160 comprises an upper confinement ring 161 and a lower confinement ring 162 which are staggered, each of the first spacers 163 of the upper confinement ring 161 and each of the second spacers 164 of the lower confinement ring 162 are staggered, and a gas channel 165 is formed between the first spacer 163 and the second spacer 164 adjacent thereto. The plasma confinement device 160 enables the gas flow to have a variety of walking environments when passing through the plasma confinement device 160 through the upper confinement ring 161 and the lower confinement ring 162 which cooperate with each other. In actual application, the positions of the corresponding upper confinement ring 161 and the lower confinement ring 162 can be set according to requirements. The plasma confinement device 160 can reduce the obstruction to the gas flow while ensuring sufficient confinement capacity for the plasma P, thereby improving the flow conductance of the reaction chamber, and helping to achieve the coordinated optimal adjustment of various process conditions, thereby ensuring the processing effect of the wafer.

[0079] Furthermore, the upper confinement ring 161 and the lower confinement ring 162 of the plasma confinement device 160 can move up and down relative to each other, and by dynamically adjusting the position of the upper confinement ring 161 and / or the lower confinement ring 162, dynamic adjustment of the conductance and plasma P limiting capability of the plasma confinement device 160 can be achieved, that is, the plasma confinement device 160 can both improve the conductance of the reaction chamber and limit the plasma P, providing a larger window of use for the process.

[0080] Furthermore, there is a potential difference between the upper confinement ring 161 and the lower confinement ring 162 of the plasma confinement device 160, so that an electric field is formed in the gas channel 165 formed between the first spacer 163 of the upper confinement ring 161 and the second spacer 164 of the adjacent lower confinement ring 162. This electric field greatly increases the confinement ability of the plasma P and also helps to improve the conductance of the reaction chamber.

[0081] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A plasma confinement device for a plasma processing device, the plasma processing device comprising a vacuum reaction chamber, wherein a lower electrode assembly is arranged in the vacuum reaction chamber, characterized in that: The plasma confinement device is arranged between the chamber side wall of the vacuum reaction chamber and the lower electrode assembly, and the plasma confinement device includes an upper confinement ring and a lower confinement ring located below the upper confinement ring, the upper confinement ring includes a plurality of first spacers surrounding the lower electrode assembly, and the lower confinement ring includes a plurality of second spacers surrounding the lower electrode assembly, each of the first spacers and each of the second spacers are arranged alternately, and a gas channel is formed between the first spacers and the second spacers adjacent to them.

2. The plasma confinement device according to claim 1, characterized in that The upper restraint ring and the lower restraint ring can move up and down relatively.

3. The plasma confinement device according to claim 2, characterized in that The upper restraint ring is fixedly arranged, and the lower restraint ring is connected to a driving device so as to move up and down.

4. The plasma confinement device according to claim 3, characterized in that The lower restraint ring includes a connection portion for connecting to the drive device; The upper confinement ring is fixedly connected to the lower electrode assembly or the vacuum reaction chamber body.

5. The plasma confinement device according to claim 2, characterized in that: The lower restraining ring is fixedly arranged, and the upper restraining ring is connected to a driving device so as to be able to move up and down.

6. The plasma confinement device according to claim 5, characterized in that The upper restraint ring includes a connection portion for connecting to the drive device; The lower confinement ring is fixedly connected to the lower electrode assembly or the vacuum reaction chamber body.

7. The plasma confinement device according to claim 1, characterized in that There is a potential difference between the upper confinement ring and the lower confinement ring.

8. The plasma confinement device according to claim 7, characterized in that The potential of the upper confinement ring is greater than the potential of the lower confinement ring; Alternatively, the potential of the lower confinement ring is greater than the potential of the upper confinement ring.

9. The plasma confinement device according to claim 7, characterized in that The upper confinement ring is connected to a bias power supply; The lower confinement ring is connected to a bias power supply.

10. The plasma confinement device according to claim 7, characterized in that The absolute value of the potential difference between the upper confinement ring and the lower confinement ring ranges from 0 kV to 100 kV.

11. The plasma confinement device according to claim 1, characterized in that The depth-to-width ratio of the gas channel is in the range of 5-20.

12. The plasma confinement device according to claim 1, characterized in that The height of the gas channel is in the range of 40% to 100% of the height of the first spacer and / or the second spacer.

13. The plasma confinement device according to claim 1, characterized in that At least some of the gas passages have equal widths; Or, the width of at least part of the gas channel increases from the center of the lower electrode assembly toward the side wall of the cavity; The spacings between at least some adjacent first spacers are equal; Or, the spacing between at least some adjacent first spacers increases from the center of the lower electrode assembly toward the side wall of the cavity; The spacings between at least some of the adjacent second spacers are equal; Alternatively, the spacing between at least some adjacent second spacers increases from the center of the lower electrode assembly toward the side wall of the cavity.

14. The plasma confinement device according to claim 1, characterized in that The width of the gas channel ranges from 0.5 mm to 5 mm.

15. The plasma confinement device according to claim 1, characterized in that The plurality of first spacers are connected by a first connecting member, and the plurality of second spacers are connected by a second connecting member.

16. The plasma confinement device according to claim 15, characterized in that The projection positions of the first connecting member and the second connecting member in the vertical direction correspond to each other; The first connecting member is disposed on the top of each of the first spacers; The second connecting member is disposed at the bottom of each of the second spacers.

17. The plasma confinement device according to claim 1, characterized in that The first spacer is made of a material comprising at least one of a conductor material or a semiconductor material; The second spacer is made of a material including at least one of a conductor material and a semiconductor material.

18. The plasma confinement device according to claim 1, characterized in that A plasma corrosion resistant film layer is disposed on the surface of the first spacer and / or the second spacer.

19. The plasma confinement device according to claim 18, characterized in that The plasma corrosion resistant film layer comprises at least one of a Teflon film layer, an yttrium oxide film layer or an anodized layer.

20. A plasma processing device, characterized in that: Include: A vacuum reaction chamber, wherein a lower electrode assembly is disposed in the vacuum reaction chamber; The plasma confinement device according to any one of claims 1 to 19, which is located in the vacuum reaction chamber.

Images