Plasma confinement system and method

Abstract

The application discloses a plasma confinement system, which is arranged in a confinement area of a reaction cavity of a plasma processing device, and is located between a processing area and an exhaust area of the reaction cavity and between a periphery of a pedestal for fixing a substrate and a side wall of the reaction cavity. The plasma confinement system is provided with a plurality of channels which are communicated with the processing area and the exhaust area, and each of the channels is distributed along a radial direction of the pedestal in the confinement area, so that waste gas generated in the processing area is transported to the exhaust area through each of the channels. The length of each of the channels is positively correlated with the original waste gas flow rate at the position of the channel. The application also discloses a plasma confinement method and a plasma processing device. The application can increase the gas flow conductance as much as possible without increasing the risk of plasma leakage, and further improve the vacuum degree of a plasma etching reaction cavity, so as to better meet the requirements of a process.

Description

Technical Field

[0001] This invention relates to the field of plasma processing, and more specifically to a plasma confinement system and method. Background Technology

[0002] Plasma processing is a common technique in the field of integrated circuits. This process step is carried out inside the reaction chamber of a plasma processor. During the process, a reaction gas containing a suitable etchant or deposition source gas is introduced into the reaction chamber. Then, high-power radio frequency power is applied to the process gas introduced into the reaction chamber through upper and lower electrodes to generate plasma. The semiconductor substrate is then processed by etching or depositing material layers on the substrate surface using plasma.

[0003] Plasma is diffusive. Although most of the plasma remains within the processing area between the upper and lower electrodes, some plasma may fill the entire reaction chamber, diffusing beyond the processing area and causing corrosion, deposition, or erosion in these areas. This leads to particle contamination inside the reaction chamber, reducing the reusability of the plasma processing device and potentially shortening the service life of the reaction chamber or its components. Furthermore, if the plasma is not confined within a defined working area, charged particles will collide with unprotected areas, resulting in impurities and contamination on the semiconductor substrate surface.

[0004] Currently, plasma confinement systems are commonly used to confine plasma. These systems have several channels through which the process waste gas generated after the etching reaction passes. This waste gas contains both charged and neutral particles. When charged particles in the plasma pass through these channels, they are neutralized, while neutral particles pass through, thus confining the discharge primarily within the processing area between the upper and lower electrodes, preventing potential cavity contamination. The plasma confinement system serves two functions: first, it confines the plasma within the processing area, preventing it from diffusing and contaminating the reaction chamber; second, it provides a channel for the process waste gas generated after the etching reaction to exit the reaction chamber. However, these two functions are contradictory. Increasing the pumping capacity inevitably increases the risk of plasma leakage from the reaction area; conversely, increasing the confinement performance reduces gas conductivity, preventing the gas from quickly passing through the plasma confinement system and exiting the reaction chamber. This leads to an increase in gas pressure within the reaction chamber, making some processes requiring low pressure impossible to execute, thus significantly limiting the process window.

[0005] However, with the continuous development of 3D NAND technology, from the initial 36-layer stacking technology to the current most advanced 128-layer stacking, the technical requirements for plasma etching are becoming increasingly higher, and the power requirements for radio frequency plasma sources are also gradually increasing. The maximum power of a 60M radio frequency plasma source needs to reach 3 to 10kW, which poses a great challenge to plasma confinement. As the power increases, the plasma concentration increases, and the increased concentration increases the difficulty of confinement. Therefore, the plasma confinement systems currently in use can no longer meet the requirements. Summary of the Invention

[0006] The purpose of this invention is to provide a plasma confinement system and method that selectively changes the aspect ratio of the gas channels in different regions of the plasma confinement system to maximize the gas conductance without increasing the risk of plasma leakage, thereby improving the vacuum level of the plasma etching reaction chamber and better meeting the process requirements.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] A plasma confinement system is provided in a confinement region within the reaction chamber of a plasma processing device. The confinement region is located between the processing region and the exhaust region of the reaction chamber, and is situated between the outer periphery of the base of a fixed substrate and the sidewall of the reaction chamber. The plasma confinement system is provided with multiple channels connecting the processing region and the exhaust region, and each channel is radially distributed along the base in the confinement region, so that the waste gas generated in the processing region is transported to the exhaust region through each channel.

[0009] The length of each channel is positively correlated with the original exhaust gas velocity at its location, where the original exhaust gas velocity is the velocity of the exhaust gas at each location in the confinement region when the plasma confinement system is not installed.

[0010] Preferably, the length of each channel gradually decreases from long to short along the centrifugal radial direction of the base.

[0011] Preferably, the opening width of each channel is negatively correlated with the original exhaust gas velocity at its location.

[0012] Preferably, the length of each channel gradually decreases from long to short along the centrifugal radial direction of the base, and the opening width of each channel gradually increases from narrow to wide along the centrifugal radial direction of the base.

[0013] Preferably, each of the channels is a plurality of concentric annular channels, and the plasma confinement system includes a set of concentric confinement rings distributed in the confinement region, with the annular channels formed by the gaps between adjacent confinement rings.

[0014] Preferably, the top of the base does not have a covering ring protruding from the sidewall of the base, and the constraint area includes a first constraint zone, a second constraint zone, and a third constraint zone arranged sequentially along the centrifugal radial direction of the base, and the original exhaust gas flow rate decreases from the first to the third constraint zone.

[0015] Preferably, the channel lengths of the first to third constraint partitions decrease in that order.

[0016] Preferably, the channel length within each of the constrained partitions decreases radially along the centrifugal axis of the base.

[0017] Preferably, the opening width of the channels in the first to third constraint partitions increases progressively.

[0018] Preferably, the channel length within each constraint partition decreases radially from the centrifugal direction of the base, and the channel opening width increases radially from the centrifugal direction of the base.

[0019] Preferably, the base has a covering ring protruding from the base sidewall at the top, the constraint area includes a first constraint zone, a second constraint zone and a third constraint zone, the covering ring covers the top of the first constraint zone but does not cover the top of the second constraint zone and the third constraint zone, and the original exhaust gas velocity of the second constraint zone is greater than that of the first and third constraint zones.

[0020] Preferably, the channel length of the second constraint partition is greater than that of the first and third constraint partitions.

[0021] Preferably, the channel opening width of the second constraint partition is smaller than that of the first and third constraint partitions.

[0022] A plasma processing device includes a reaction chamber with a base inside. A substrate is fixed to the top of the base by an electrostatic clamp. A spray head is positioned above the base to introduce reactive gas into the reaction chamber. A processing area is formed between the spray head and the base, and the processing area is surrounded by the chamber wall of the reaction chamber. The spray head serves as the upper electrode, and the base serves as the lower electrode, where high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area into plasma. The plasma reaching the upper surface of the substrate processes the substrate. The plasma processing device has an exhaust area at the bottom of the reaction chamber, which is connected to an external exhaust pump.

[0023] The aforementioned plasma confinement system is installed in the confinement area, and a grounding ring for support and conductive grounding is provided below the plasma confinement system.

[0024] A plasma confinement method, wherein the plasma confinement system described above is disposed in the confinement region within the reaction chamber of a plasma processing device;

[0025] During the process of sending the exhaust gas generated in the treatment area to the exhaust area through the channels, charged particles are neutralized, achieving plasma confinement.

[0026] The distribution density of the channels is related to the plasma distribution density at the location: where the plasma distribution density is high, the channel distribution density is high, which enhances the plasma confinement capability; where the plasma distribution density is low, the channel distribution density is low, which increases the gas flow rate.

[0027] A plasma confinement system is provided, comprising a confinement region disposed within the reaction chamber of a plasma processing device. The confinement region is located between the processing region and the exhaust region of the reaction chamber, and is situated between the outer periphery of the base of the fixed substrate and the sidewall of the reaction chamber.

[0028] The base is provided with a covering ring protruding from the side wall of the base. The plasma confinement system is provided with multiple channels connecting the processing area and the exhaust area. Each of the channels is radially distributed in the confinement area, so that the exhaust gas generated in the processing area is transported to the exhaust area through each of the channels.

[0029] The opening width of each channel is negatively correlated with the original exhaust gas velocity at its location, where the original exhaust gas velocity is the velocity of the exhaust gas at each location in the confinement region when the plasma confinement system is not installed.

[0030] The constraint area includes a first constraint zone, a second constraint zone, and a third constraint zone arranged sequentially along the centrifugal radial direction of the base. The covering ring covers the top of the first constraint zone but does not cover the top of the second and third constraint zones. The original exhaust gas velocity of the second constraint zone is greater than that of the first and third constraint zones.

[0031] The plasma confinement system is provided with a grounding ring for support and conductive grounding below it.

[0032] Preferably, the channel opening width of the second constraint partition is smaller than that of the first and third constraint partitions.

[0033] A plasma processing device includes a reaction chamber with a base inside. A substrate is fixed to the top of the base by an electrostatic clamp. A spray head is positioned above the base to introduce reactive gas into the reaction chamber. A processing area is formed between the spray head and the base, and the processing area is surrounded by the chamber wall of the reaction chamber. The spray head serves as the upper electrode, and the base serves as the lower electrode, where high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area into plasma. The plasma reaching the upper surface of the substrate processes the substrate. The plasma processing device has an exhaust area at the bottom of the reaction chamber, which is connected to an external exhaust pump. The aforementioned plasma confinement system is disposed in the confinement area.

[0034] A plasma confinement method, wherein the plasma confinement system described above is disposed in the confinement region within the reaction chamber of a plasma processing device;

[0035] During the process of sending the exhaust gas generated in the treatment area to the exhaust area through the channels, charged particles are neutralized, achieving plasma confinement.

[0036] The distribution density of the channels is related to the plasma distribution density at the location: where the plasma distribution density is high, the channel distribution density is high, which enhances the plasma confinement capability; where the plasma distribution density is low, the channel distribution density is low, which increases the gas flow rate.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] 1. Simple structure, easy to implement;

[0039] 2. It can effectively improve the confinement performance of plasma confinement systems;

[0040] 3. Without increasing the risk of plasma leakage, maximizing the gas conductivity can ensure that the gas conductivity is sufficient to meet a larger process window. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of a prior art capacitively coupled plasma processing device without a cover ring.

[0043] Figure 1a , 1bThis is a schematic diagram of the structure of two plasma confinement systems of an embodiment of the present invention applicable to a capacitively coupled plasma processing device without a cover ring.

[0044] Figure 2 This is a schematic diagram of a prior art capacitively coupled plasma processing device with a covered ring.

[0045] Figure 2a , 2b Figures 2 and 2c are schematic diagrams of three plasma confinement systems of the present invention applicable to a capacitively coupled plasma processing device with a covered ring. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on the invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0047] In the following description, references to "some embodiments" or "one or more embodiments" describe a subset of all possible embodiments. However, it is understood that "some embodiments" or "one or more embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0048] In the following description, the terms "first, second, third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the invention described herein can be implemented in an order other than that shown in the illustrations or description.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0050] Figure 1A capacitively coupled plasma processing device without a cover ring is shown, comprising a vacuum-ejectable reaction chamber surrounded by reaction chamber walls. The reaction chamber contains a base 3 for fixing a substrate 4 and a spray head 2 for introducing reactive gas into the reaction chamber. The processing area A between the spray head 2 and the base 3 is surrounded by the reaction chamber walls. Typically, the spray head 2 serves as the upper electrode, and the base 3 serves as the lower electrode, where high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area A into plasma. The plasma reaching the upper surface of the substrate 4 can perform etching and other processes on the substrate 4. The plasma processing device has an exhaust region B at a suitable position at the bottom of the reaction chamber 1. In some embodiments, the exhaust region B is an annular region close to the bottom of the reaction chamber 1 and surrounding the base 3. The exhaust region B is connected to an external exhaust pump 7 to extract the process waste gas generated after the etching reaction during the processing from the reaction chamber.

[0051] Furthermore, a confinement region is also included between the processing area A and the exhaust area B, and between the outer perimeter of the base 3 and the sidewall 1 of the reaction chamber. In order to confine the plasma within the processing area A and prevent it from diffusing out and corroding the unprotected equipment, a plasma confinement system 6 is provided in the confinement region. Figure 1A prior art plasma confinement system 6 is shown, comprising a set of confinement rings. Multiple concentric annular channels are formed by gaps between adjacent confinement rings. Each channel connects to the processing area A and the exhaust area B. The channels are uniformly distributed horizontally, with the same length and the same radial width (width between adjacent channels) along the base 3. Due to the elongated gaps between adjacent sidewalls of each channel, when process waste gas is discharged through these channels, charged particles in the waste gas collide with other particles and the channel sidewalls. By calculating the mean free path of the particles in the plasma, their kinetic energy is dissipated in the collisions before escaping from the channels, thus confining the charged particles within the channels while allowing neutral particles to pass through. This essentially confines the discharge to the processing area A, achieving plasma confinement. Therefore, the plasma confinement system 6 has two functions: 1. confining the plasma to the processing area A, preventing the plasma from diffusing out of the processing area A and contaminating the exhaust area B of the reaction chamber; 2. providing a channel for the process waste gas to exit the reaction chamber. However, the two functions mentioned above are contradictory. Increasing the pumping capacity will inevitably increase the risk of plasma leakage from the reaction area; while increasing the confinement performance will reduce the gas conductivity, preventing the gas from quickly passing through the plasma confinement system 6 and exiting the reaction chamber. This will cause the gas pressure inside the reaction chamber to rise, making some processes requiring low gas pressure impossible to execute, thus greatly limiting the process window. However, as the technical requirements of plasma etching become increasingly stringent, the power requirements of the radio frequency plasma source are gradually increasing. Due to the increase in power, the plasma concentration increases, and in order to prevent plasma leakage, the pumping performance must be greatly suppressed. Conversely, if the pumping capacity is reduced, it will not be suitable for the low gas pressure required for current high aspect ratio etching. Therefore, the existing plasma confinement system 6 cannot meet the higher process requirements.

[0052] The technical problem this invention aims to solve is to maximize gas conductivity without increasing the risk of plasma leakage, thereby improving the vacuum level of the plasma etching reaction chamber to better meet process requirements. The principle of this invention is that the risk of plasma leakage is positively correlated with gas flow rate; areas with higher gas flow rates have a greater risk of plasma leakage, while areas with lower gas flow rates have a lower risk. Experimental measurements show that the original gas flow rate (the original waste gas flow rate is the flow rate of waste gas passing through various locations in the confinement area without the plasma confinement system 6) varies at different locations. Therefore, by selectively adjusting the gas flow rate at different locations, relatively increasing the gas flow rate at locations with lower original gas flow rates (i.e., locations with lower plasma leakage risk) and relatively decreasing the gas flow rate in areas with higher original gas flow rates (i.e., locations with higher plasma leakage risk), the goal of maximizing gas conductivity without increasing the risk of plasma leakage can be achieved.

[0053] Furthermore, because the longer the gas flow channel, the greater the reduction in gas velocity; and the narrower the gas flow channel, the greater the reduction in gas velocity; therefore, the present invention regulates the gas velocity by setting different lengths and widths, or length and width, of the channels at different locations in the plasma confinement system 6. Specifically, the present invention achieves this regulation based on the original gas velocity at each location in the confinement region through three methods: 1. Setting the channel length at each location in the plasma confinement system 6 according to a positive correlation with the original gas velocity; 2. Setting the channel opening width at each location in the plasma confinement system 6 according to a negative correlation with the original gas velocity; 3. Setting the channel length at each location in the plasma confinement system 6 according to a positive correlation with the original gas velocity, and simultaneously setting the channel opening width at each location in the plasma confinement system 6 according to a negative correlation with the original gas velocity. Specifically:

[0054] Combination Figure 1 , Figure 1a , Figure 1b and Figure 2 , Figure 2a , Figure 2b As shown, the present invention provides a plasma confinement system, which is a confinement area disposed in the reaction chamber of a plasma processing device. The confinement area is an annular space located between the processing area A and the exhaust area B of the reaction chamber, and between the base 3 of the fixed substrate and the side wall 1 of the reaction chamber.

[0055] The plasma confinement system of the present invention is provided with multiple channels connecting the processing area A and the exhaust area B, and each channel is radially distributed in the confinement area along the base 3 (the base 3 is a column with a vertical central axis; the radial direction mentioned in the present invention is a general understanding of radial direction: that is, the direction perpendicular to the central axis of the base 3; the vertical projection of the base 3 is not limited to being circular, but in the preferred embodiment described below, the vertical projection of the base 3 will be exemplarily described as circular), so that the process waste gas generated in the processing area A can be transported to the exhaust area B through each of the channels, and when the process waste gas is discharged through these channels, the charged particles in the process waste gas are neutralized, and neutral particles can pass through, thereby achieving plasma confinement. In some embodiments, each channel is a plurality of concentric annular channels, and the plasma confinement system includes a set of concentric confinement rings distributed in the confinement area, and the annular channels are formed by the gaps between adjacent confinement rings.

[0056] In some embodiments, the channel lengths at different locations of the plasma confinement system are not uniform, and the channel lengths at each location are set according to a positive correlation with the original exhaust gas velocity at that location, wherein the original exhaust gas velocity is the velocity of the exhaust gas passing through each confinement location when the plasma confinement system is not in place. In other embodiments, the channel opening widths at different locations of the plasma confinement system are not uniform, and the channel opening widths at each location are set according to a negative correlation with the original exhaust gas velocity at that location. In still other embodiments, both the channel length and width at different locations of the plasma confinement system are not uniform, wherein the channel length at each location is set according to a positive correlation with the original exhaust gas velocity at that location, and the channel opening width at each location is set according to a negative correlation with the original exhaust gas velocity at that location.

[0057] In some embodiments, the constraint region is sequentially divided into three annular subspaces along the centrifugal radial direction of the base 3: a first constraint partition 61, a second constraint partition 62, and a third constraint partition 63, wherein the second constraint partition 62 is fitted outside the first constraint partition 61, and the third constraint partition 63 is fitted outside the second constraint partition 62. The centrifugal radial direction of the base 3 refers to the radial direction radiating outward from the outer periphery of the base 3, and conversely, the radial direction is the centripetal radial direction.

[0058] Figure 1 For a capacitively coupled plasma processing device without a cover ring, the original gas flow rate in its confined region was first determined by experimental methods, and the original gas flow rate decreased along the centrifugal radial direction of the base.

[0059] Figure 1a , 1b This invention is applicable to Figure 1Examples of two plasma confinement systems in the capacitively coupled plasma processing apparatus without a cover ring are shown.

[0060] in, Figure 1a The diagram illustrates some embodiments of adjusting gas flow rate by setting the channel length at various locations of the plasma confinement system 6. Specifically, in some embodiments, the channel lengths of the first confinement partition 61, the second confinement partition 62, and the third confinement partition 63 decrease sequentially; in some embodiments, the channel lengths of the first confinement partition 61, the second confinement partition 62, and the third confinement partition 63 decrease sequentially, and the channel length within each confinement partition decreases along the centrifugal radial direction of the base 3.

[0061] Figure 1b This diagram illustrates some embodiments of controlling gas flow rate by simultaneously setting the channel length and width at various locations of the plasma confinement system 6. Specifically, in some embodiments, the channel lengths of the first confinement partition 61, the second confinement partition 62, and the third confinement partition 63 decrease sequentially, while the channel opening widths increase sequentially. In other embodiments, the channel lengths of the first confinement partition 61, the second confinement partition 62, and the third confinement partition 63 decrease sequentially, while the channel opening widths increase sequentially. Furthermore, within each confinement partition, the channel length decreases along the centrifugal radial direction of the base 3, while the channel opening width increases along the centrifugal radial direction of the base 3. By increasing the channel length in regions with high initial gas flow rates or decreasing the channel opening width in those regions, the plasma confinement capability of those regions can be enhanced. Conversely, by decreasing the channel length in regions with low initial gas flow rates or increasing the channel opening width in those regions, the gas flow rate in those regions can be enhanced. With appropriate design based on different process requirements, such as in high aspect ratio etching, this approach can simultaneously increase the overall pumping rate of the chamber, reduce chamber pressure, and limit plasma leakage.

[0062] In addition, to improve the electric field distribution between the upper and lower electrodes of the plasma processing device and avoid tip discharge at the edge of the lower electrode, thereby achieving higher process standards, as shown in the attached... Figure 2 As shown, the prior art also includes a capacitively coupled plasma processing device with a covering ring, which is connected to... Figure 1 Compared to the capacitively coupled plasma processing device without a cover ring shown, the difference lies in that: a cover ring 5 protruding from the sidewall of the base 3 is provided on the top of the base 3. This cover ring 5 extends a certain distance into the confinement area, covering the first confinement partition 61 but not covering the second and third confinement partitions 62 and 63. This can reduce the original gas flow rate of the first confinement partition 61, thereby reducing the risk of plasma leakage in the first confinement partition 61. The relationship of the original gas flow rates of each confinement partition is as follows: the original exhaust gas flow rate of the second confinement partition 62 is greater than that of the first and third confinement partitions 61 and 63.

[0063] Figure 2a , 2b 2c illustrates the applicability of the present invention. Figure 2 The diagram shows a structural schematic of three embodiments of the plasma confinement system in a capacitively coupled plasma processing apparatus with a covered ring.

[0064] in, Figure 2a This is a schematic diagram of some embodiments of regulating gas flow rate by setting the channel length at various locations of the plasma confinement system 6, wherein the channel length of the second confinement partition 62 is greater than the channel lengths of the first confinement partition 61 and the third confinement partition 63.

[0065] Figure 2b This is a schematic diagram of some embodiments of regulating gas flow rate by setting the channel opening width at various locations of the plasma confinement system 6, wherein the channel opening width of the second confinement partition 62 is smaller than that of the first confinement partition 61 and the third confinement partition 63.

[0066] Figure 2c This is a schematic diagram of some embodiments for regulating gas flow rate by simultaneously setting the channel length and opening width at various locations of the plasma confinement system 6. The channel length of the second confinement partition 62 is greater than the channel lengths of the first confinement partition 61 and the third confinement partition 63, and the channel opening width of the second confinement partition 62 is smaller than that of the first confinement partition 61 and the third confinement partition 63.

[0067] Each of the aforementioned plasma confinement systems is equipped with a grounding ring for support and conductive grounding to prevent the accumulation of charged particles on the channel sidewalls and to allow for timely neutralization of charges through the grounding ring.

[0068] This embodiment also provides a plasma processing device, including a reaction chamber, a base disposed within the reaction chamber, and a substrate fixed to the top of the base by an electrostatic clamp; a spray head is disposed above the base to introduce reactive gas into the reaction chamber; a processing area is formed between the spray head and the base, and the processing area is surrounded by the chamber wall of the reaction chamber; the spray head serves as the upper electrode, and the base serves as the lower electrode, and high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area into plasma, which then processes the substrate by reaching the upper surface of the substrate; the plasma processing device has an exhaust area at the bottom of the reaction chamber, and the exhaust area is connected to an external exhaust pump;

[0069] Furthermore, the plasma confinement system of the present invention described above is disposed in the confinement area, and a grounding ring for support and conductive grounding is provided below the plasma confinement system.

[0070] This embodiment also provides a plasma confinement method, wherein the plasma confinement system of the present invention described above is disposed in the confinement area within the reaction chamber of a plasma processing device;

[0071] During the process of sending the exhaust gas generated in the treatment area to the exhaust area through the channels, charged particles are neutralized, achieving plasma confinement.

[0072] The distribution density of the channels is related to the plasma distribution density at the location: where the plasma distribution density is high, the channel distribution density is high, which enhances the plasma confinement capability; where the plasma distribution density is low, the channel distribution density is low, which increases the gas flow rate.

[0073] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

Claims

1. A plasma confinement system, comprising a confinement region disposed within a reaction chamber of a plasma processing device, the confinement region being located between a processing region and an exhaust region of the reaction chamber, and situated between the outer periphery of a fixed substrate and the sidewall of the reaction chamber, characterized in that, The plasma confinement system is provided with multiple channels connecting the processing area and the exhaust area, and each of the channels is radially distributed in the confinement area along the base, so that the exhaust gas generated in the processing area is transported to the exhaust area through each of the channels. The length of each channel is positively correlated with the original exhaust gas velocity at its location, where the original exhaust gas velocity is the velocity of the exhaust gas at each location in the confinement region when the plasma confinement system is not installed.

2. The plasma confinement system as described in claim 1, characterized in that, The opening width of each channel is negatively correlated with the original exhaust gas velocity at its location.

3. The plasma confinement system as described in claim 1, characterized in that, Each of the channels is a plurality of concentric annular channels. The plasma confinement system includes a set of confinement rings distributed concentrically in the confinement region, and the annular channels are formed by the gaps between adjacent confinement rings.

4. The plasma confinement system as described in claim 1 or 2, characterized in that, The constraint region includes a first constraint zone, a second constraint zone, and a third constraint zone arranged sequentially along the centrifugal radial direction of the base, and the original exhaust gas flow rate decreases from the first to the third constraint zone.

5. The plasma confinement system as described in claim 4, characterized in that, The opening width of the channels in the first to third constraint partitions increases progressively.

6. The plasma confinement system as described in claim 4, characterized in that, The channel lengths of the first to third constraint partitions decrease sequentially.

7. The plasma confinement system as described in claim 6, characterized in that, The channel length within each of the constrained partitions decreases radially along the centrifugal axis of the base.

8. The plasma confinement system as described in claim 6, characterized in that, The opening width of the channels in the first to third constraint partitions increases progressively.

9. The plasma confinement system as described in claim 1, characterized in that, The base is provided with a covering ring protruding from the side wall of the base. The constraint area includes a first constraint zone, a second constraint zone, and a third constraint zone. The covering ring covers the top of the first constraint zone but does not cover the top of the second and third constraint zones. The original exhaust gas velocity of the second constraint zone is greater than that of the first and third constraint zones.

10. The plasma confinement system as described in claim 9, characterized in that, The channel length of the second constraint partition is greater than that of the first and third constraint partitions.

11. The plasma confinement system as described in claim 9, characterized in that, The channel opening width of the second constraint partition is smaller than that of the first and third constraint partitions.

12. A plasma processing apparatus includes a reaction chamber, a base disposed within the reaction chamber, and a substrate fixed to the top of the base by an electrostatic clamp; a spray head disposed above the base to introduce reactive gas into the reaction chamber; a processing area is formed between the spray head and the base, and the processing area is surrounded by the chamber wall of the reaction chamber; the spray head serves as the upper electrode, and the base serves as the lower electrode, and high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area into plasma, which then processes the substrate by reaching the upper surface of the substrate; the plasma processing apparatus has an exhaust area at the bottom of the reaction chamber, and the exhaust area is connected to an external exhaust pump; Its features are, The plasma confinement system according to any one of claims 1-11 is disposed in the confinement area, and a grounding ring for support and conductive grounding is provided below the plasma confinement system.

13. A plasma confinement method, characterized in that, Within the reaction chamber of the plasma processing device, the plasma confinement system according to any one of claims 1-11 is disposed in the confinement region; During the process of the exhaust gas generated in the treatment area being sent to the exhaust area through the various channels, charged particles are neutralized, achieving plasma confinement. The distribution density of the channels is related to the plasma distribution density at their location: where the plasma distribution density is high, the channel distribution density is high, enhancing the plasma confinement capability; where the plasma distribution density is low, the channel distribution density is low, increasing the gas flow rate.

14. A plasma confinement system for a plasma processing apparatus, characterized in that, The plasma processing device includes a reaction chamber, a base disposed within the reaction chamber, a plasma processing area above the base, a plasma confinement system disposed around the base, and an exhaust area below the plasma confinement system. The plasma confinement system is provided with multiple channels connecting the processing area and the exhaust area, and each channel is radially distributed along the base, so that the exhaust gas generated in the processing area is transported to the exhaust area through each channel; the plasma confinement system includes a first confinement zone, a second confinement zone, and a third confinement zone arranged sequentially along the centrifugal radial direction of the base, and a covering ring is provided at the top edge of the base, which covers the top of the first confinement zone but does not cover the top of the second and third confinement zones; the channel length of the second confinement zone is greater than the channel length of the first and third confinement zones, and / or the channel opening width of the second confinement zone is smaller than that of the first and third confinement zones.

15. The plasma confinement system as described in claim 14, characterized in that, Along the centrifugal radial direction of the base, the depth of each channel in the first constraint partition gradually increases; the centrifugal radial direction of the base refers to the direction along the radius of the base and away from the center of the base.

16. The plasma confinement system as described in claim 14, characterized in that, Along the centrifugal radial direction of the base, the width of each channel in the first constraint partition gradually decreases; the centrifugal radial direction of the base refers to the direction along the radius of the base and away from the center of the base.

17. The plasma confinement system as described in claim 14, characterized in that, Along the centrifugal radial direction of the base, the depth of each channel in the third constraint partition gradually decreases; the centrifugal radial direction of the base refers to the direction along the radius of the base and away from the center of the base.

18. The plasma confinement system as described in claim 14, characterized in that, Along the centrifugal radial direction of the base, the width of each channel in the third constraint partition gradually increases; the centrifugal radial direction of the base refers to the direction along the radius of the base and away from the center of the base.

19. A plasma processing apparatus, characterized in that, include: A reaction chamber is disposed within a base, the base being used to support the substrate; The covering ring is partially located on the periphery of the base and partially protrudes from the side wall of the base; The plasma confinement system according to any one of claims 14 to 18, surrounding the periphery of the base, the plasma confinement system includes a first confinement zone, a second confinement zone, and a third confinement zone arranged sequentially along the centrifugal radial direction of the base, the second confinement zone being disposed around the first confinement zone, the covering ring covering the first confinement zone but not covering the second and third confinement zones, the channel length of the second confinement zone being greater than the channel length of the first and third confinement zones, and / or, the channel opening width of the second confinement zone being smaller than that of the first and third confinement zones.

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