Constraint Ring, Plasma Processing Apparatus, and Exhaust Control Method Thereof

Abstract

A constraint ring, a plasma processing apparatus and an exhaust control method thereof. The constraint ring is disposed around the periphery of a pedestal in a reaction chamber of the plasma processing apparatus and between the side walls of the reaction chamber. The constraint ring includes at least one annular component forming an annular structure. The annular component includes a main body portion having a plurality of gas channels and a height adjustment device for adjusting the height of the gas channels. By driving the height adjustment device in the annular component to move, the height of the gas channels in the annular component is adjusted, thereby adjusting the gas flow distribution in the reaction chamber. In the present invention, the height of the gas channels in the constraint ring is uniformly or separately adjusted in multiple regions, thereby adjusting and balancing the gas flow distribution in the reaction chamber, with strong operability and high adaptability. The present invention can reduce the air pressure in the reaction chamber without changing the intake gas flow rate, which is beneficial to the gas exchange in the reaction chamber and the extraction of reaction by-products, reduces the deposition of reaction by-products on the wafer, and thus improves the etching performance.

Description

Technical Field

[0001] The present invention relates to a device in the semiconductor field, and in particular to a confinement ring, a plasma processing device and an exhaust control method thereof. Background Art

[0002] The plasma treatment process used in integrated circuit manufacturing includes a plasma deposition process and a plasma etching process. In the process of processing wafers through a plasma treatment process, the wafer is first fixed in a plasma reaction chamber, and a patterned microelectronic layer is formed on the wafer. Then, the RF power transmitter transmits RF energy into the plasma reaction chamber to form an RF electric field; then various reaction gases (etching gas or deposition gas) are injected into the plasma reaction chamber, and the injected reaction gas is excited into a plasma state above the wafer under the action of the RF electric field; finally, chemical reactions and / or physical actions (such as etching, deposition, etc.) occur between the plasma and the wafer to form various characteristic structures, and the volatile reaction products formed in the chemical reaction are separated from the surface of the etched material and are extracted out of the plasma reaction chamber by the vacuum system.

[0003] In order to prevent the reaction byproducts from carrying the plasma to areas outside the plasma processing area when they are discharged from the reaction chamber and causing damage to the area, a plasma confinement ring (FEIS Ring) is usually set between the base supporting the wafer and the side wall of the reaction chamber. The confinement ring has multiple gas channels that penetrate the upper and lower surfaces of the confinement ring. The confinement ring can ensure that when the plasma gas formed above the base flows through the confinement ring, all the charged particles in it are extinguished and become neutral gas flowing downward.

[0004] As the technology nodes of the semiconductor industry are gradually reduced, the requirements for small hole etching are getting higher and higher in plasma etching with decreasing feature size (CD critical dimension), especially when the feature size is below 3nm. For example, in the etching of small holes of BARC (Bottom Anti-Reflective Coatings), when the feature size reaches 3nm, the BARC in the small hole will easily remain at the bottom of the hole, affecting the subsequent process. The residue of BARC at the bottom of the hole is due to the very small feature size, which makes it more difficult for the etching gas to enter and the by-products to be extracted, resulting in reduced etching performance and affecting the wafer processing quality and processing rate.

[0005] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art. Summary of the invention

[0006] The object of the present invention is to provide a restraint ring, a plasma processing apparatus and an exhaust control method thereof, which have strong operability and high adaptability, are conducive to gas exchange in the reaction chamber and extraction of reaction by-products, reduce deposition of reaction by-products on the wafer, and improve etching performance.

[0007] To achieve the above object, the present invention provides a restraint ring for a plasma processing apparatus. The plasma processing apparatus includes a reaction chamber, and a susceptor for supporting a substrate is disposed in the reaction chamber. The restraint ring is disposed around the susceptor and between the side walls of the reaction chamber, and the restraint ring includes: at least one annular component, and the annular components together form an annular structure;

[0008] The annular component includes:

[0009] a main body portion having a plurality of gas channels for discharging gas to an exhaust region below the restraint ring;

[0010] a height adjustment device for adjusting the height of the gas channels.

[0011] The height adjustment device includes: an extension member movably disposed along the side wall of the gas channel, and the shape of the extension member matches the shape of the gas channel.

[0012] On the one hand, when the gas channel is an annular channel, the main body portion includes: at least two concentrically arranged arc-shaped baffles.

[0013] The lengths of the arc-shaped baffles decrease successively from the outer side wall to the inner side wall of the reaction chamber.

[0014] The main body portion includes: at least one connecting rib for connecting the arc-shaped baffles.

[0015] The height adjustment device includes: at least two concentrically arranged arc-shaped baffle extension pieces movably connected to the arc-shaped baffles.

[0016] The arc-shaped baffle extension piece has a groove for accommodating the arc-shaped baffle.

[0017] The length of the arc-shaped baffle extension piece matches the length of the arc-shaped baffle it accommodates.

[0018] On the other hand, when the gas channel is a hole-shaped channel, the main body portion includes: a plurality of through holes.

[0019] The height adjustment device includes: a plurality of extension tubes movably disposed in the through holes matching them.

[0020] The height of the gas channel is greater than or equal to twice the width of the gas channel.

[0021] The number of the annular components is at least two. The annular components are in a fan-shaped structure, and the central angles of the annular components are equal or unequal.

[0022] The annular component further includes: a connecting piece, which is used to fixedly connect the annular component to the side wall of the reaction chamber.

[0023] The height adjusting device further includes: at least one lifting rod, which is connected to the arc-shaped baffle extension piece or the extension pipe, and the lifting rod is used to drive the arc-shaped baffle extension piece or the extension pipe to move up and down.

[0024] The height adjusting device further includes: a driving device, which is used to drive the lifting rod to move.

[0025] The driving device includes one of a motor device, a hydraulic device or a pneumatic device.

[0026] It further includes a control mechanism for controlling the operation of the driving device.

[0027] The present invention further provides a plasma processing device, including:

[0028] A reaction chamber, in which a base for supporting a substrate is provided;

[0029] The constraint ring is disposed around the periphery of the base between the base and the side wall of the reaction chamber.

[0030] The present invention further provides an exhaust control method for a plasma processing device, including the following steps:

[0031] Providing the plasma processing device as described above; and

[0032] When it is necessary to adjust the reaction chamber environment in the plasma processing device, the driving device is used to drive the height adjusting device in the annular component to move, and the height of the gas channel in the annular component is adjusted;

[0033] By adjusting the height of the gas channel in the annular component, the gas flow distribution in the reaction chamber is adjusted.

[0034] The driving device drives the lifting rod to drive the arc-shaped baffle extension piece or the extension pipe to move up and down, thereby adjusting the height of the gas channel in the annular component.

[0035] On the one hand, the heights of the gas channels in different annular components are the same.

[0036] On the other hand, the heights of the gas channels in different annular components are different.

[0037] The height of the gas channel in the annular component decreases successively according to the distance of the annular component from the exhaust area from near to far.

[0038] By uniformly or separately adjusting the height of the gas channel in the restraint ring in multiple regions, the present invention adjusts and balances the gas flow distribution in the reaction chamber, with strong operability and high adaptability. Without changing the intake gas flow, the present invention can reduce the air pressure in the reaction chamber, which is beneficial to gas exchange in the reaction chamber and the extraction of reaction by-products, and reduce the deposition of reaction by-products on the wafer, thereby improving the etching performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of a plasma processing device including a restraint ring.

[0040] Figure 2 It is a schematic diagram of the thickness of the restraint ring and the width of the gas channel of the present invention.

[0041] Figure 3 It is a schematic diagram of the change of the lowest limit value of the air pressure in the reaction chamber with the opening degree of the vacuum pump valve under different heights of the restraint ring of the present invention.

[0042] Figure 4 It is a schematic diagram of the comparison of the residues at the bottom of the small holes under different heights of the restraint ring in the etching of small holes with a feature size less than 10 nm of the present invention.

[0043] Figure 5 It is a top view of the restraint ring provided in an embodiment of the present invention.

[0044] Figure 6 In an embodiment Figure 5 It is a cross-sectional view taken along line B-B.

[0045] Figure 7 In another embodiment Figure 5 It is a cross-sectional view taken along line B-B.

[0046] Figure 8 It is a top view of the restraint ring provided in the third embodiment of the present invention.

[0047] Figure 9 It is a top view of the restraint ring provided in the fourth embodiment of the present invention.

[0048] Figure 10 It is a top view of the restraint ring provided in another embodiment of the present invention.

[0049] Figure 11 It is Figure 10 It is a cross-sectional view taken along line C-C. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The following is based onFigures 1 - 11 , specifically illustrate the preferred embodiments of the present invention.

[0051] Figure 1 A plasma processing apparatus including a confinement ring is shown. The plasma processing apparatus 1 has a reaction chamber 10, the reaction chamber 10 is substantially cylindrical, and the side wall of the reaction chamber is substantially vertical. There are an upper electrode 11 and a lower electrode 13 oppositely arranged in the reaction chamber 10. Generally, the area between the upper electrode 11 and the lower electrode 13 is the processing area A, and high-frequency energy will be formed in this processing area A to ignite and maintain the plasma. The lower electrode 13 includes a base 131, and a wafer W to be processed is placed above the base 131. The reaction gas is input from the gas source 12 into the reaction chamber 10. One or more radio frequency power supplies 14 can be individually applied to the lower electrode 13 or simultaneously and separately applied to the upper electrode 11 and the lower electrode 13 to deliver radio frequency power to the lower electrode 13 or the upper electrode 11 and the lower electrode 13, so as to generate a large electric field inside the reaction chamber 10. Most of the electric field lines are contained in the processing area A between the upper electrode 11 and the lower electrode 13. This electric field accelerates a small amount of electrons existing inside the reaction chamber 11, causing them to collide with the gas molecules of the input reaction gas. These collisions lead to the ionization of the reaction gas and the excitation of the plasma, thereby generating plasma in the reaction chamber 10. The neutral gas molecules of the reaction gas lose electrons when experiencing these strong electric fields, leaving positively charged ions. The positively charged ions accelerate towards the direction of the lower electrode 13 and combine with the neutral substances in the wafer W to be processed, exciting the processing of the wafer W, namely etching, deposition, etc. An exhaust area is provided at a suitable position of the plasma processing apparatus 1. The exhaust area is connected to an external exhaust device (such as a vacuum pump 15) to extract the used reaction gas and by-product gas from the processing area A during the processing, and establish an appropriate pressure in the processing area A through gas flow. Figure 1 The plasma processing apparatus 1 in also includes a fixedly arranged confinement ring 16, and the confinement ring 16 is arranged around the periphery of the base between the side wall of the reaction chamber. The charged particles in the plasma are extinguished by the confinement ring 16 to prevent the inner wall of the reaction chamber and the exhaust pipe below the confinement ring from being contaminated.

[0052] As Figure 2 shown, the confinement ring has a plurality of gas channels 17 penetrating through the upper and lower surfaces of the confinement ring. The opening size and depth of these gas channels 17 are designed to ensure that when the plasma gas formed above the base flows through the confinement ring, all the ions in it are extinguished and become neutral gas flowing downward. The confinement ring needs to be able to well limit the plasma and meet the condition: the height S' of the gas channels 17 on the confinement ring is greater than or equal to twice the width g' of the gas channels.

[0053] In the etching of small holes in BARC (Bottom Anti-Reflective Coatings), in order to improve the entry of etching gas and the extraction of by-products, a process regime that makes the pressure in the plasma reaction chamber smaller and the gas flow rate larger is preferred, so as to obtain a faster etching rate in the small holes and reduce the residue of BARC in the holes.

[0054] When the air pressure in the reaction chamber remains unchanged, the valve opening of the vacuum pump 15 will increase with the increase in the gas flow rate input from the gas source 12; when the gas flow rate reaches a certain value, the valve opening of the vacuum pump 15 will reach the maximum limit. To ensure that the air pressure in the reaction chamber remains unchanged, the gas flow rate cannot be increased further. On the other hand, when the gas flow rate input into the reaction chamber 10 remains unchanged, there is also a minimum limit for the air pressure value in the reaction chamber 10 (at this time, the valve opening reaches the maximum limit). In some etching processes, we hope to reduce the air pressure in the reaction chamber without changing the gas flow rate, which helps to extract reaction by-products and reduce the deposition of reaction by-products on the wafer.

[0055] As Figure 3 shown, in an experiment, provided as Figure 1Two plasma processing apparatuses 1 are shown. Each of the two plasma processing apparatuses 1 is provided with a confinement ring 16. The height of the confinement ring in one plasma reaction apparatus 1 is a, and the height of the confinement ring in the other plasma reaction apparatus 1 is 1.5a. The gas flow rates of the reaction gases input into the reaction chambers 10 of the two plasma processing apparatuses 1 are the same. When the height of the confinement ring is a, the lowest limit value of the pressure in the reaction chamber 10 can reach 15 mT, and with the change of the valve opening degree of the vacuum pump 15, the adjustment range of the lowest limit value of the pressure in the reaction chamber 10 is 10 - 25 mT. When the height of the confinement ring is 1.5a, the lowest limit value of the pressure in the reaction chamber 10 can only reach 20 mT, and the adjustment range of the lowest limit value of the pressure in the reaction chamber 10 is 20 - 25 mT. This experiment proves that adjusting the height of the confinement ring 16 can broaden the pressure adjustment range in the reaction chamber 10 and increase the window of process parameters. Moreover, when the valve opening degrees are the same, the pressure with the confinement ring height of a is lower than that with the confinement ring height of 1.5a. Therefore, reducing the height of the confinement ring 16 is beneficial to increasing the conductance in the reaction chamber 10. Thus, when the same gas flow enters, a lower pressure can be achieved in the reaction chamber 10. The reduction of the pressure in the reaction chamber 10 helps the reactants to enter the small holes and the extraction of reaction by-products, and reduces the deposition of reaction by-products on the wafer W. The plasma processing apparatus that limits the pressure in the reaction chamber 10 is proven to be able to fabricate and / or form continuously shrinking features on the wafer W. In the etching process, when the gas flow rate remains unchanged, the smaller the pressure value in the reaction chamber 10, the more beneficial it is for gas exchange in the reaction chamber and the extraction of reaction by-products, thereby improving the etching performance.

[0056] Through the two plasma reaction apparatuses 1 used in the above experiment, the influence of the height of the confinement ring 16 on the wafer small hole etching process is further verified. Figure 4 It shows a comparison diagram of two TEM (Transmission Electron Microscope) results of small hole etching when the feature size is less than 10 nm. Figure 4 For the left and right figures in it, the plasma processing apparatuses 1 respectively adopt confinement rings 16 with heights of a and 1.5a. Figure 4 It shows that under the same process parameters, when the height of the confinement ring is a, there is no residue of reaction by-products at the bottom of the small hole ( Figure 4 left figure); while when the height of the confinement ring is 1.5a, there is obvious residue of reaction by-products at the bottom of the small hole ( Figure 4 right figure).

[0057] The need to reduce the height of the confinement ring to suit the BARC layer etching process was exemplarily described above. It can be seen that the height adjustment of the confinement ring 16 has a significant impact on the gas pressure inside the reaction chamber 10. Since multiple different etching processes need to be carried out in one reaction chamber, some processes require a large flow rate of process gas and a low gas pressure, while some processes are the opposite. Therefore, by changing the height of the confinement ring 16, the gas pressure inside the reaction chamber 10 can meet different process requirements.

[0058] Based on this, the present invention provides a confinement ring 16 for a plasma processing apparatus, which is disposed around the periphery of the base between the side walls of the reaction chamber, as Figure 5 shown. In this embodiment, the confinement ring 16 includes a complete circular ring-shaped component 23. The ring-shaped component 23 includes a fixed main body part and a height adjustment device that is detachably connected to and movable relative to the main body part. The main body part has a plurality of gas channels 17 for discharging gas to the exhaust area below the confinement ring. The height adjustment device is used to adjust the height of the gas channels 17. As Figure 5 and Figure 6 shown, the main body part includes a plurality of circular baffles 19. Gas channels 17 are formed between adjacent circular baffles 19. The circular baffles 19 are arranged concentrically. The diameters of the circular baffles 19 decrease sequentially from the side wall of the reaction chamber from outside to inside to ensure that gas channels 17 are formed between adjacent circular baffles 19. The widths of the gas channels 17 can be the same. In other embodiments, the widths of the gas channels 17 can also be set to be different. Exemplarily, the outermost circular baffle 19 can be fixed to the side wall of the reaction chamber to complete the fixation of the circular ring-shaped component 23, or a connecting member (not shown in the figure) can be used to fixedly connect the circular ring-shaped component 23 to the side wall of the reaction chamber. Further, connecting ribs 20 are used to connect all the circular baffles 19 to prevent the circular baffles 19 from falling off. The connecting ribs 20 can be located below all the circular baffles 19, that is, on the side away from the processing area A. In other embodiments, since the height adjustment device is generally installed below the main body part, in order to prevent the connecting ribs 20 from hindering the operation of the height adjustment device, the connecting ribs 20 can be arranged at a position relatively close to the top of the main body part. Since a complete circular ring-shaped component 23 is used in this embodiment, several connecting ribs 20 can be arranged along the radial direction of the circular ring-shaped component 23 to ensure the uniformity and stability of the connection. As Figure 5 and Figure 6As shown, the height adjustment device includes a plurality of annular baffle extension pieces 21. The material of the annular baffle extension pieces 21 is the same as that of the annular baffle 19, and both the annular baffle extension pieces 21 and the annular baffle 19 have undergone surface treatment. The number of the annular baffle extension pieces 21 is the same as that of the annular baffle 19, and the annular baffle extension pieces 21 are also arranged concentrically. The annular baffle extension pieces 21 have grooves, and the shape and size of the grooves match those of the annular baffle 19. Each annular baffle 19 is correspondingly arranged in the groove of the annular baffle extension piece 21 that matches it. The thickness of the two side walls of the groove of the annular baffle extension piece 21 should not be too thick, and it should be ensured that it does not affect the width of the gas passage 17 determined by the annular baffle 19. In order to support the annular baffle extension pieces 21 and realize the up and down movement of the annular baffle extension pieces 21, a connecting rod 22 is provided, which is fixedly connected to all the annular baffle extension pieces 21. The connecting rod 22 drives the annular baffle extension pieces 21 to move up and down under the drive of a driving device (not shown in the figure). When the annular baffle extension piece 21 moves upward, it partially overlaps with the annular baffle 19, reducing the height of the gas passage 17. When the annular baffle extension piece 21 moves downward, the annular baffle 19 at least partially protrudes from the annular baffle extension piece 21, increasing the height of the gas passage 17. Similarly, since a complete annular ring assembly 23 is adopted in this embodiment, several connecting rods 22 can be arranged along the radius direction of the annular ring assembly 23 to ensure the uniformity and stability of the connection. As Figure 6 shown, in this embodiment, the connecting rod 22 is arranged at the bottom of the annular baffle extension piece 21, which is convenient for connecting the driving device. As Figure 7 shown, in another embodiment, the connecting rod 22 can be arranged in the middle of the annular baffle extension piece 21 and connected to the side walls of the annular baffle extension piece 21 respectively, and the function of driving all the annular baffle extension pieces 21 to move up and down simultaneously can also be achieved. The driving device includes one or several of a motor device, a hydraulic device or a pneumatic device. The driving device can be automatically controlled by a computer system according to the semiconductor manufacturing process, or can be controlled manually according to the semiconductor manufacturing process. In the above embodiment, the driving device drives the connecting rod 22 to drive the annular baffle extension piece 21 to move up and down along the annular baffle 19, realizing the height adjustment of the gas passage 17. According to the needs of the manufacturing process, by reducing the height of the gas passage 17 in the restraint ring 16, the air pressure in the reaction chamber is reduced, which is beneficial to the gas exchange in the reaction chamber and the extraction of reaction by-products, reducing the deposition of reaction by-products on the wafer, and thus improving the etching performance.

[0059] In another embodiment of the present invention, asFigure 8 As shown, the restraint ring 16 can be composed of a plurality of fan-shaped components 18, and all the fan-shaped components 18 together form an annular structure. The structure of the fan-shaped component 18 is the same as that of the annular component 23 shown in Figures 5 - 7 , and it also includes a fixed main body part and a height adjustment device that is detachably connected to and movable relative to the main body part. In this embodiment, the central angle of each fan-shaped component 18 is set to be the same. For example, 6 or 8 fan-shaped components 18 can be evenly arranged. As shown in Figure 8 , the main body part includes a plurality of arc-shaped baffles 19'. Gas channels 17' are formed between adjacent arc-shaped baffles 19'. The arc-shaped baffles 19' are concentrically arranged, and the length of the arc-shaped baffles 19' decreases sequentially from the side wall of the reaction chamber from outside to inside to ensure that the width of each gas channel 17' is the same. The outermost arc-shaped baffle 19' is fixed to the side wall of the reaction chamber to complete the fixation of the fan-shaped component 18, or a connecting member (not shown in the figure) can be used to fixedly connect the fan-shaped component 18 to the side wall of the reaction chamber. Further, a connecting rib 20' is used to connect all the arc-shaped baffles 19' to prevent the arc-shaped baffles 19' from falling off. In this embodiment, if the central angle of a single fan-shaped component 18 is not large (such as less than 60°), then only a single connecting rib 20' can be used. If the central angle of a single fan-shaped component 18 is relatively large (such as more than 60°), then two or three connecting ribs 20' can be considered to ensure the uniformity and stability of the connection. As shown in Figure 8 and Figure 6As shown, the height adjustment device includes a plurality of arc-shaped baffle extension pieces 21'. The number of the arc-shaped baffle extension pieces 21' is the same as that of the arc-shaped baffles 19', and the arc-shaped baffle extension pieces 21' are also concentrically arranged. The arc-shaped baffle extension pieces 21' have grooves, and the shape and size of the grooves match those of the arc-shaped baffles 19'. Each arc-shaped baffle 19' is correspondingly arranged in the groove of the arc-shaped baffle extension piece 21' that matches it, and the length of each arc-shaped baffle extension piece 21' is equal to the length of the arc-shaped baffle 19' that matches it. The thickness of the two side walls of the groove of the arc-shaped baffle extension piece 21' should not be too thick, and it should be ensured that it does not affect the width of the gas passage 17' determined by the arc-shaped baffle 19'. In order to support the arc-shaped baffle extension pieces 21' and enable the up and down movement of the arc-shaped baffle extension pieces 21', a connecting rod 22' is provided, which is fixedly connected to all the arc-shaped baffle extension pieces 21'. The connecting rod 22' drives the arc-shaped baffle extension pieces 21' to move up and down under the drive of a driving device (not shown in the figure). When the arc-shaped baffle extension piece 21' moves upward, it partially overlaps with the arc-shaped baffle 19', reducing the height of the gas passage 17'. When the arc-shaped baffle extension piece 21' moves downward, the arc-shaped baffle 19' at least partially extends out of the arc-shaped baffle extension piece 21, increasing the height of the gas passage 17'. Similarly, if the central angle of a single fan-shaped component 18 is small (such as less than 60°), then only a single connecting rod 22' can be used. If the central angle of a single fan-shaped component 18 is relatively large (such as more than 60°), then two or three connecting rods 22' can be considered to ensure the uniformity and stability of the connection. As Figure 6 shown, in this embodiment, the connecting rod 22' is arranged at the bottom of the arc-shaped baffle extension piece 21' for facilitating its connection to the driving device. As Figure 7 shown, in another embodiment, the connecting rod 22' can be arranged in the middle of the arc-shaped baffle extension piece 21' and respectively connected to the side walls of the arc-shaped baffle extension piece 21', and the function of driving all the arc-shaped baffle extension pieces 21' to move up and down simultaneously can also be achieved. The driving device includes one or several of a motor device, a hydraulic device or a pneumatic device. The driving device can be automatically controlled by a computer system according to the semiconductor manufacturing process, or can be controlled manually according to the semiconductor manufacturing process.

[0060] In the above embodiment, the driving connecting rod 22' is driven to drive the arc baffle extension piece 21' to move up and down along the arc baffle 19', so as to realize the height adjustment of the gas channel 17'. In this embodiment, because a plurality of fan-shaped ring components 18 are provided, the height of the gas channel 17' in each fan-shaped ring component 18 can be adjusted separately. The height of the gas channels 17' in all the fan-shaped ring components 18 can be adjusted to the same height, or the height of the gas channels 17' in each fan-shaped ring component 18 can be adjusted separately according to the process requirements. Since the exhaust device in the reaction chamber is usually arranged on one side of the bottom wall of the reaction chamber, some of the fan-shaped ring components 18 in the restraint ring 16 are closer to the exhaust device, and correspondingly, the reactants are extracted faster, while some of the fan-shaped ring components 18 in the restraint ring 16 are farther from the exhaust device, and correspondingly, the reactants are extracted slower. To adapt to this situation, the height of the gas channel 17' in the fan-shaped ring component 18 closer to the exhaust device can be reduced, and the height of the gas channel 17' in the fan-shaped ring component 18 farther from the exhaust device can be adjusted lower, so that the height of the gas channel 17' in the fan-shaped ring component 18 decreases in turn according to the distance of the fan-shaped ring component 18 from the exhaust device. This can not only balance the air pressure in different regions of the reaction chamber, but also reduce the air pressure in the reaction chamber, which is beneficial to gas exchange in the reaction chamber and the extraction of reaction by-products, reduce the deposition of reaction by-products on the wafer, and thus improve the etching performance.

[0061] In another embodiment of the present invention, as Figure 9 shown, the restraint ring 16 may be composed of a plurality of fan-shaped ring components 18, and all the fan-shaped ring components 18 together form an annular structure. The structure of the fan-shaped ring component 18 is the same as that of the Figures 5 - 7 circular ring-shaped component 23 shown in, and also includes a fixed main body part and a height adjustment device that is detachably connected to and movable relative to the main body part. The difference between this embodiment and the Figure 8 embodiment shown is that the central angle of each fan-shaped ring component 18 is set to be different. For example, the central angle of the fan-shaped ring component 18 closer to the exhaust device can be set to be smaller (such as less than 60°), and the central angle of the fan-shaped ring component 18 farther from the exhaust device can be set to be larger (such as greater than 120°), or the size and length of each fan-shaped ring component 18 can be specifically set according to the process requirements. In this way, by separately adjusting the height of the gas channels 17 in different fan-shaped ring components 18, a more precise adjustment of the air pressure in the entire reaction chamber can be realized. By reducing the height of the gas channels 17 in the restraint ring 16, the air pressure in the reaction chamber can be reduced, which is beneficial to gas exchange in the reaction chamber and the extraction of reaction by-products, reduce the deposition of reaction by-products on the wafer, and thus improve the etching performance.

[0062] In another embodiment of the present invention, the present invention provides a confinement ring 16-1 for a plasma processing apparatus, which is disposed around the periphery of the base between the side walls of the reaction chamber, as Figure 10 shown. In this embodiment, the confinement ring 16-1 includes a complete circular ring-shaped component 23-1, and the ring-shaped component 23-1 includes a fixed main body portion, and a height adjustment device that is detachably connected to and movable relative to the main body portion. The main body portion has a plurality of gas channels 17-1 for discharging gas to the exhaust area below the confinement ring, and the height adjustment device is used to adjust the height of the gas channels 17-1. As Figure 10 shown, the main body portion includes a plurality of through holes 24, and each through hole 24 forms a gas channel 17-1. The through holes 24 can be arranged disorderly or in an orderly queue, for example, they can be arranged in concentric rings to form multiple concentric rings, or they can be arranged radially along the radius of the circular ring-shaped component 23-1. By setting the diameter of the through holes 24, the diameters of the gas channels 17-1 can be set to be the same or different. The circular ring-shaped component 23-1 can be directly fixed to the side wall of the reaction chamber, or a connecting member (not shown in the figure) can be used to fixedly connect the circular ring-shaped component 23-1 to the side wall of the reaction chamber. As Figure 11As shown, the height adjustment device includes a plurality of extension tubes 25. The material of the extension tubes 25 is the same as that of the circular ring-shaped component 23-1, and both the extension tubes 25 and the circular ring-shaped component 23-1 have undergone surface treatment. The number of the extension tubes 25 is the same as the number of the through holes 24. The outer diameter size of the extension tubes 25 matches the inner diameter size of the through holes 24. Each extension tube 25 is correspondingly arranged in the through hole 24 that matches it. The side wall thickness of the extension tubes 25 should not be too thick to ensure that it does not affect the diameter of the gas passage 17-1 determined by the through hole 24. To support the extension tubes 25 and enable the up and down movement of the extension tubes 25, a connecting rod 26 is provided, which is fixedly connected to all the extension tubes 25. The connecting rod 26 drives the extension tubes 25 to move up and down under the drive of a driving device (not shown in the figure). When the extension tubes 25 move upward, they partially overlap with the through holes 24, reducing the height of the gas passage 17-1. When the extension tubes 25 move downward, the extension tubes 25 at least partially extend out of the through holes 24, increasing the height of the gas passage 17-1. Similarly, since a complete circular ring-shaped component 23-1 is used in this embodiment, several connecting rods 26 can be arranged along the radial direction of the circular ring-shaped component 23-1 to ensure the uniformity and stability of the connection. In this embodiment, the connecting rod 26 is arranged at the bottom of the extension tubes 25 for facilitating its connection with the driving device. In another embodiment, the connecting rod 26 can be arranged in the middle of the extension tubes 25 and be respectively connected to the side walls of the extension tubes 25, which can also achieve the function of driving all the extension tubes 25 to move up and down simultaneously. The driving device includes one or several of a motor device, a hydraulic device or a pneumatic device. The driving device can be automatically controlled by a computer system according to the semiconductor manufacturing process, or can be controlled manually according to the semiconductor manufacturing process.

[0063] In the above embodiment, the driving device drives the connecting rod 26 to drive the extension tubes 25 to move up and down along the through holes 24, realizing the height adjustment of the gas passage 17-1. According to the needs of the manufacturing process, by reducing the height of the gas passage 17-1 in the restraint ring 16-1, the air pressure in the reaction chamber is reduced, which is beneficial to the gas exchange in the reaction chamber and the extraction of reaction by-products, reducing the deposition of reaction by-products on the wafer, thereby improving the etching performance.

[0064] Similarly, the restraint ring 16-1 can also be composed of a plurality of sector ring-shaped components (not shown in the figure). All the sector ring-shaped components together form a circular structure. The structure of the sector ring-shaped component is the same as Figures 10 - 11The structure of the circular ring-shaped component 23-1 shown is the same, which also includes a fixed main body part and a height adjustment device that is detachably connected to the main body part and is movable. In this embodiment, the central angles of each sector-shaped component are set to be the same or different. In this way, by separately adjusting the heights of the gas channels in different sector-shaped components, more precise adjustment of the air pressure in the entire reaction chamber can be achieved. By reducing the height of the gas channels in the constraint ring, the air pressure in the reaction chamber can be reduced, which is beneficial to gas exchange in the reaction chamber and the extraction of reaction by-products, reduces the deposition of reaction by-products on the wafer, and thus improves the etching performance. The height-adjustable plasma constraint ring disclosed in the present invention can be applied to various different process processes of plasma processing devices. It reduces the efficiency loss caused by opening the chamber to replace plasma constraint rings with different heights when switching between different processes. At the same time, when the plasma constraint ring is set as several sector-shaped components, the dynamic adjustment of the air pressure distribution at different positions in the reaction chamber can be achieved by adjusting the heights of the gas channels of the sector-shaped components at different positions, ensuring that the pressures in all regions of the processing area A are the same or deliberately making the pressures inconsistent to achieve compensation for other parameters. The driving device for controlling the lifting of the extension piece in the present invention can use a computer system to automatically control the driving device according to the semiconductor process, or can be manually controlled according to the semiconductor process by an operator to achieve flexible adjustment.

[0065] In the present invention, by uniformly or separately adjusting the heights of the gas channels in the constraint ring in multiple regions, the gas flow distribution in the reaction chamber is adjusted and balanced, with strong operability and high adaptability. Without changing the intake gas flow rate, the air pressure in the reaction chamber can be reduced in the present invention, which is beneficial to gas exchange in the reaction chamber and the extraction of reaction by-products, reduces the deposition of reaction by-products on the wafer, and thus improves the etching performance.

[0066] It should be noted that in the embodiments of the present invention, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0067] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and alternatives to the present invention will be obvious. Therefore, the protection scope of the present invention shall be defined by the appended claims.

Claims

1. A confinement ring for a plasma processing apparatus, the plasma processing apparatus comprising a reaction chamber in which a susceptor for supporting a substrate is disposed, characterized in that, The constraint ring is disposed around the periphery of the base and between the side walls of the reaction chamber. The constraint ring includes: at least one annular component, and the annular components together form an annular structure; The annular component includes: A main body portion, the main body portion includes: at least two concentric arc-shaped baffles. The main body portion has a plurality of gas channels, and the gas channels are annular channels for discharging gas to the exhaust area below the constraint ring; A height adjusting device detachably connected to and movable relative to the main body portion, the height adjusting device being used to adjust the height of the gas channels. The height adjusting device includes: at least two concentric arc-shaped baffle extensions movably disposed along the side walls of the annular channels. The shape of the arc-shaped baffle extensions matches the shape of the annular channels. The arc-shaped baffle extensions are movably connected to the arc-shaped baffles. The arc-shaped baffle extensions have grooves for accommodating the arc-shaped baffles.

2. The confinement ring for a plasma processing apparatus according to claim 1, wherein The lengths of the arc-shaped baffles decrease successively from the side wall of the reaction chamber from outside to inside.

3. The confinement ring for a plasma processing apparatus according to claim 2, wherein, The main body portion includes: at least one connecting rib for connecting the arc-shaped baffles.

4. The confinement ring for a plasma processing apparatus according to claim 3, characterized in that, The length of the arc-shaped baffle extension matches the length of the arc-shaped baffle it accommodates.

5. The confinement ring for a plasma processing apparatus according to claim 1, characterized in that, The height of the gas channels is greater than or equal to twice the width of the gas channels.

6. The confinement ring for a plasma processing apparatus according to claim 1, wherein The number of the annular components is at least two. The annular components are in a fan-shaped structure, and the central angles of the annular components are equal or unequal.

7. The confinement ring for a plasma processing apparatus according to claim 6, wherein The annular component further includes: a connecting member for fixedly connecting the annular component to the side wall of the reaction chamber.

8. The confinement ring for a plasma processing apparatus according to claim 1, characterized in that, The height adjusting device further includes: at least one lifting rod connecting the arc-shaped baffle extensions, and the lifting rod is used to drive the arc-shaped baffle extensions to move up and down.

9. The confinement ring for a plasma processing apparatus according to claim 8, characterized in that, The height adjusting device further includes: a driving device for driving the lifting rod to move.

10. The confinement ring for a plasma processing apparatus according to claim 9, characterized in that, The driving device includes one of a motor device, a hydraulic device or a pneumatic device.

11. The confinement ring for a plasma processing apparatus according to claim 10, characterized in that, It further includes a control mechanism for controlling the operation of the driving device.

12. A confinement ring for a plasma processing apparatus, the plasma processing apparatus comprising a reaction chamber, and a susceptor disposed in the reaction chamber for supporting a substrate, characterized in that, The constraint ring is disposed around the periphery of the base and between the side walls of the reaction chamber. The constraint ring includes: at least one annular component, and the annular components together form an annular structure; The annular component includes: A main body portion, the main body portion includes: a plurality of through holes. The main body portion has a plurality of gas channels, and the gas channels are hole-shaped channels for discharging gas to the exhaust area below the constraint ring; A height adjusting device detachably connected to and movable relative to the main body portion, the height adjusting device being used to adjust the height of the gas channels. The height adjusting device includes: a plurality of extension tubes movably disposed in the through holes matching them, and the extension tubes are movably disposed along the side walls of the hole-shaped channels. The shape of the extension tubes matches the shape of the hole-shaped channels.

13. The confinement ring for a plasma processing apparatus according to claim 12, characterized in that, The height of the gas channels is greater than or equal to twice the width of the gas channels.

14. The confinement ring for a plasma processing apparatus according to claim 12, wherein, The number of the annular components is at least two. The annular components are in a fan-shaped structure, and the central angles of the annular components are equal or unequal.

15. The confinement ring for a plasma processing apparatus according to claim 14, characterized in that, The annular component further includes: a connecting member for fixedly connecting the annular component to the side wall of the reaction chamber.

16. The confinement ring for a plasma processing apparatus according to claim 12, wherein The height adjusting device further includes: at least one lifting rod connected to the extension pipe, and the lifting rod is used to drive the extension pipe to move up and down.

17. The confinement ring for a plasma processing apparatus according to claim 16, wherein, The height adjusting device further includes: a driving device for driving the lifting rod to move.

18. The confinement ring for a plasma processing apparatus according to claim 17, wherein The driving device includes one of a motor device, a hydraulic device, or a pneumatic device.

19. The confinement ring for a plasma processing apparatus according to claim 18, wherein, It further includes a control mechanism for controlling the operation of the driving device.

20. A plasma processing apparatus, characterized in that, Includes: A reaction chamber with a pedestal for supporting a substrate disposed therein; The restraint ring according to any one of claims 1-11, the restraint ring being disposed around the periphery of the pedestal and between the side walls of the reaction chamber.

21. An exhaust gas control method for a plasma processing apparatus, characterized in that, Includes the following steps: Providing the plasma processing device according to claim 20, wherein the height adjusting device in the restraint ring of the plasma processing device includes: at least one lifting rod connected to the arc-shaped baffle extension; And When it is necessary to adjust the reaction chamber environment in the plasma processing device, the driving device is used to drive the lifting rod to drive the arc-shaped baffle extension to move up and down, thereby adjusting the height of the gas channel in the annular component; By adjusting the height of the gas channel in the annular component, the gas flow distribution in the reaction chamber is adjusted.

22. The exhaust gas control method of the plasma processing apparatus according to claim 21, characterized in that, The heights of the gas channels in different annular components are the same.

23. The exhaust control method of the plasma processing apparatus according to claim 21, characterized in that, The heights of the gas channels in different annular components are different.

24. The exhaust gas control method of the plasma processing apparatus according to claim 23, characterized in that, The height of the gas channel in the annular component decreases successively according to the distance of the annular component from the exhaust area from near to far.

25. A plasma processing apparatus, characterized in that, Includes: A reaction chamber with a pedestal for supporting a substrate disposed therein; The restraint ring according to any one of claims 12-19, the restraint ring being disposed around the periphery of the pedestal and between the side walls of the reaction chamber.

26. An exhaust gas control method for a plasma processing apparatus, characterized in that, Includes the following steps: Providing the plasma processing device according to claim 25, wherein the height adjusting device in the restraint ring of the plasma processing device includes: at least one lifting rod connected to the extension pipe; And When it is necessary to adjust the reaction chamber environment in the plasma processing device, the driving device is used to drive the lifting rod to drive the extension pipe to move up and down, thereby adjusting the height of the gas channel in the annular component; By adjusting the height of the gas channel in the annular component, the gas flow distribution in the reaction chamber is adjusted.

27. The exhaust gas control method of the plasma processing apparatus according to claim 26, wherein, The heights of the gas channels in different annular components are the same.

28. The exhaust gas control method of the plasma processing apparatus according to claim 26, wherein, The heights of the gas channels in different annular components are different.

29. The exhaust gas control method of the plasma processing apparatus according to claim 28, characterized in that, The height of the gas channel in the annular component decreases successively according to the distance of the annular component from the exhaust area from near to far.

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