Plasma confinement ring, plasma processing apparatus, and method of processing semiconductor

Abstract

The application discloses a plasma confinement ring, a plasma processing device and a method for processing a semiconductor. The plasma confinement ring is arranged in a reaction cavity of the plasma processing device. The plasma confinement ring comprises a ring-shaped side wall and a gas passage wall fixedly connected with the ring-shaped side wall. The ring-shaped side wall is arranged on a supporting ring which is fixed with a side wall of the reaction cavity. A heat insulation gap is arranged in the ring-shaped side wall and used for slowing down heat transfer from the gas passage wall to the side wall of the reaction cavity. The application can make the temperature of the plasma confinement ring reach a preset temperature and be kept, thereby achieving the purpose of preventing polymer deposition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor processing equipment, in particular to a plasma confinement ring, a plasma processing equipment and a method for processing semiconductor. BACKGROUND

[0002] When etching a semiconductor substrate using a plasma processing equipment, a plasma confinement ring is needed to be set around the susceptor, i.e. the path of the pumping, so that the plasma in the reaction space reaches electrical neutrality before being pumped to the bottom of the reaction chamber.

[0003] During the process, the pumped gas in the reaction chamber will transfer heat to the sidewall of the gas passage of the plasma confinement ring, so that the plasma confinement ring maintains a certain temperature. However, the temperature on the plasma confinement ring will decrease due to heat loss, which makes the by-products generated in the reaction process easily deposit on the sidewall of the gas passage. Especially in the high aspect ratio etching process, due to the long etching time, the polymer accumulates quickly, which narrows the gas passage, affects the gas flow speed, and even blocks part of the gas passage, thereby causing uneven etching on the surface of the substrate. SUMMARY

[0004] The purpose of the present application is to provide a plasma confinement ring, a plasma processing equipment and a method for processing semiconductor, which can solve the problem that the pumping passage (gas passage or annular passage) is narrowed due to the low temperature of the plasma confinement ring, which affects the pumping speed and even blocks the pumping passage, thereby affecting the high aspect ratio etching process.

[0005] In order to solve the above problems, the present application realizes the following technical scheme:

[0006] A plasma confinement ring is arranged in a reaction chamber of a plasma processing equipment, the plasma confinement ring comprises an annular sidewall and a gas passage wall fixedly connected with the annular sidewall; the annular sidewall is placed on a support ring, the support ring is fixed with the sidewall of the reaction chamber, and further comprises: a heat insulation gap arranged in the annular sidewall, used for slowing down the heat transfer from the gas passage wall to the sidewall of the reaction chamber.

[0007] Optionally, the heat insulation gap comprises a gap A extending axially along the annular sidewall.

[0008] Optionally, the gap A is a group of at least two gaps, wherein the two gaps A have openings on the surface of the annular sidewall, and the directions of the two openings are opposite.

[0009] Optionally, the gap A is arranged close to the gas passage wall.

[0010] Optionally, the heat insulation slit comprises a slit B extending radially along the annular sidewall.

[0011] Optionally, the slit B is a slit group with at least two slits B, wherein two of the slits B have openings on the surface of the annular sidewall, and the directions of the two openings are opposite.

[0012] Optionally, the slit B is arranged close to the support ring.

[0013] Optionally, the slit width of the heat insulation slit is 0.2mm-2mm.

[0014] Optionally, the annular sidewall comprises an annular inner sidewall and an annular outer sidewall, the gas passage wall is located between the annular inner sidewall and the annular outer sidewall, and the heat insulation slit is located in the annular inner sidewall and / or the annular outer sidewall.

[0015] Optionally, the gas passage wall is composed of a plurality of concentrically arranged nested rings with different diameters, the plurality of nested rings are fixedly connected to the annular sidewall through spokes located at the lower part of the nested rings, and the spokes are provided with slits C extending axially along the annular sidewall at the connection with the annular inner sidewall and / or the annular outer sidewall.

[0016] Optionally, the slit width of the slit C is 0.5mm-1mm.

[0017] Optionally, the gas passage wall is composed of a circular ring body with a plurality of through holes.

[0018] Optionally, the heat insulation slit is in the shape of a circular ring, and the circular ring body is provided with slits C extending axially along the annular sidewall at the connection with the annular inner sidewall and / or the annular outer sidewall.

[0019] Optionally, the heat insulation slit is in the shape of a circular ring.

[0020] Optionally, the support ring is a conductor, the plasma confinement ring is grounded, and the support ring is provided with slits extending radially along the support ring.

[0021] Optionally, the heat insulation slit is filled with a heat insulation material.

[0022] Optionally, the annular inner sidewall, the annular outer sidewall and the gas passage wall are designed integrally.

[0023] Further, the application also discloses a plasma processing device, comprising: a reaction cavity, wherein a pedestal for carrying a substrate is arranged in the reaction cavity;

[0024] a gas injection device for conveying reaction gas into the reaction cavity;

[0025] The plasma confinement ring according to any one of the above is arranged around the periphery of the pedestal.

[0026] Further, a method for processing a semiconductor using the plasma processing apparatus is disclosed, comprising:

[0027] delivering a reaction gas into the reaction chamber;

[0028] ionizing the reaction gas into plasma and etching a semiconductor substrate on the susceptor in the reaction chamber;

[0029] during etching, slowing down heat transfer from the gas passage wall to the sidewall of the reaction chamber through the heat insulation gap, so that the gas passage wall is maintained at a temperature at which etching polymer does not deposit.

[0030] Compared with the prior art, the present application has at least one of the following advantages:

[0031] The plasma confinement ring provided by the present application slows down heat transfer from the gas passage to the sidewall of the reaction chamber by arranging the heat insulation gap on the annular outer sidewall and / or annular inner sidewall. That is, the arrangement of the heat insulation gap is equivalent to adding a large-area heat insulation layer on the annular outer sidewall and / or annular inner sidewall. In this way, for example, when the heat insulation gap is arranged on the annular outer sidewall, heat of the plasma confinement ring can only flow to the sidewall of the reaction chamber through the residual thin wall on the inner side of the annular outer sidewall, thereby greatly reducing heat transfer from the plasma confinement ring to the sidewall, and further enabling the gas passage to maintain a temperature to prevent polymer deposition.

[0032] The heat insulation gap is annular, that is, the first gap to the fourth gap are annular. Due to the skin effect of the radio frequency current, when the radio frequency frequency is >100 kHz, the distribution depth of the radio frequency current on the plasma confinement ring (made of aluminum or its alloy) is <0.3 mm, and the radio frequency current only flows through the inner surface and bottom surface of the sidewall of the plasma confinement ring. Therefore, the heat insulation gap provided by the present application does not affect the radio frequency current channel from the plasma confinement ring to the MGR (support ring), and thus does not affect the plasma distribution in the reaction chamber.

[0033] The third gap is closer to the inner side than the fourth gap, thereby making the heat transfer path from the gas passage of the plasma confinement ring to the sidewall of the reaction chamber longer, thereby more easily enabling the temperature of the plasma confinement ring to reach a preset temperature and be maintained, thereby achieving the purpose of preventing polymer deposition. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Partial cross-sectional structure schematic diagram of the plasma confinement ring provided by an embodiment of the present application;

[0035] Figure 2A partial cross-sectional view of a plasma confinement ring according to another embodiment of the present application is shown in FIG. 2B.

[0036] Figure 3 A partial cross-sectional view of a plasma confinement ring according to another embodiment of the present application is shown in FIG. 2B.

[0037] Figure 4 A top view of a plasma confinement ring according to another embodiment of the present application is shown in FIG. 2C.

[0038] Figure 5 A schematic view of a main structure of a plasma processing apparatus according to an embodiment of the present application is shown in FIG. 3.

[0039] Figure 6 A partial cross-sectional view of a plasma confinement ring according to another embodiment of the present application is shown in FIG. 2B. DETAILED DESCRIPTION

[0040] A plasma confinement ring, a plasma processing apparatus, and a method of processing a semiconductor according to the present application will be described in further detail below with reference to the drawings. The advantages and features of the present application will become more apparent from the following description taken in conjunction with the accompanying drawings. It is to be understood that the drawings are designed solely for purposes of illustration and are not intended to limit the scope of the present application, and that portions thereof can be exaggerated, omitted or simplified, and the numbering of the various elements in the drawings is done for the convenience of specific embodiments disclosed herein and is not intended to limit the scope of the present application. Thus, the technical spirit of the present application should not be limited to the specific embodiments disclosed herein but should be accorded the full scope that can be implied by the language disclosed herein.

[0041] Embodiment 1

[0042] As Figure 1As shown, the embodiment provides a plasma confinement ring, which is arranged in a reaction chamber 100 of a plasma processing device, the sidewall of the reaction chamber 100 is provided with an inward and radially extending extension step 101, the plasma confinement ring comprises a ring-shaped sidewall and a gas passage wall 300, the ring-shaped sidewall can be specifically divided into a ring-shaped outer sidewall 302 and a ring-shaped inner sidewall 303; the gas passage wall 300 is arranged inside between the ring-shaped outer sidewall 302 and the ring-shaped inner sidewall 303; the ring-shaped outer sidewall 302 is placed on a support ring 400, and the support ring 400 is placed above the extension step 101; in other embodiments, the support ring can also be connected with the sidewall of the reaction chamber in other ways except the extension step, for example, fixed by screws; the plasma confinement ring further comprises a heat insulation gap arranged on the ring-shaped outer sidewall 302 and / or the ring-shaped inner sidewall 303, which is used to slow down the heat transfer from the gas passage wall 300 to the sidewall of the reaction chamber 100.

[0043] Therefore, the plasma confinement ring provided by the embodiment can slow down the heat transfer from the gas passage to the sidewall of the reaction chamber by arranging the heat insulation gap on the ring-shaped outer sidewall and / or the ring-shaped inner sidewall, wherein the ring-shaped outer sidewall is located between the gas passage and the sidewall of the reaction chamber and serves as an intermediate structure for heat transfer; the arrangement of the heat insulation gap on the ring-shaped outer sidewall will not affect the exhaust path of the gas, and it is also easy to process a structure with a specific shape; and since the heat insulation gap is located in the middle of the heat transfer, the heat can be significantly controlled on the side of the gas passage. That is, the arrangement of the heat insulation gap is equivalent to adding a large-area heat insulation layer on the ring-shaped outer sidewall and / or the ring-shaped inner sidewall. In this way, for example, when the heat insulation gap is arranged on the ring-shaped outer sidewall, the heat of the plasma confinement ring can only flow to the sidewall of the reaction chamber through the residual thin wall on the inner side of the ring-shaped outer sidewall, thereby greatly reducing the heat transfer from the plasma confinement ring to the sidewall, and further enabling the gas passage to maintain a temperature and prevent polymer deposition.

[0044] Please continue to refer to Figure 1 As shown, the heat insulation gap comprises a gap B extending radially along the ring-shaped outer sidewall, and the number of the gap B can be one, for example, a first gap 3011 formed in the ring-shaped outer sidewall 302; in other embodiments, the number of the gap B can also be multiple; the first gap 3011 is arranged close to the support ring 400, and close means closer to the lower surface of the ring-shaped sidewall relative to the upper surface of the ring-shaped sidewall, so that the ring-shaped sidewall is divided into upper and lower parts, and the upper part has a larger thermal mass relative to the lower part; the first gap reduces the speed of heat loss from the upper part to the lower part of the ring-shaped sidewall, that is, reduces the temperature change of the upper part; and the first gap 3011 extends radially along the ring-shaped outer sidewall 302, and the first gap 3011 can be formed in the ring-shaped outer sidewall 302 as shown in the figure, or can be formed on the support ring 400 as shown in the figure. Figure 1The first gap 3011 can be opened towards the side wall of the reaction cavity, away from the side wall of the reaction cavity, or closed, as shown in Figure 1 The first gap 3011 is shown to connect the upper and lower parts of the annular outer side wall 302, and the contact area between the lower part and the bottom surface remains unchanged, maintaining the stability of the support. The upper part is connected to the lower part only by a small part, reducing the cross-sectional area of the channel for heat transfer from the upper part to the lower part, i.e. significantly reducing the temperature balance speed of the upper and lower parts.

[0045] Please continue to refer to Figure 1 The embodiment also includes a plurality of horizontal spokes 301 and a plurality of nested rings, a plurality of said horizontal spokes 301 are arranged between said annular outer side wall 302 and said annular inner side wall 303 in a circumferential direction, a plurality of said nested rings are located on said horizontal spokes 301 and connected to said annular outer side wall 302 and said annular inner side wall 303 through horizontal spokes 301, and the gap between two adjacent said nested rings constitutes said gas channel; a gap C3010 is provided at the connection between each said horizontal spoke 301 and said annular outer side wall 302 and / or the connection between said annular inner side wall 303, said gap C3010 is used to slow down the heat transfer from said gas channel to the side wall of the reaction cavity.

[0046] The opening direction of the gap C3010 can be downward or upward, as shown in Figure 1 The downward opening embodiment shown makes the heat of the gas channel wall 300 only pass through a small part of the horizontal spoke 301 connected to the annular outer side wall 302, reducing the cross-sectional area of heat transfer at this point, i.e. said gap C3010 slows down the flow speed of heat from said gas channel wall 300 to the annular outer side wall 302, i.e. reduces the heat transfer to the side wall of the reaction cavity 100.

[0047] In this embodiment, the first gap 3011 is annular. A plurality of nested rings are arranged at equal intervals and concentrically.

[0048] Based on this embodiment, in order to improve the heat insulation effect of the heat insulation gap and improve the mechanical properties of the horizontal spoke 301 and the annular outer side wall 302, a heat insulation material can be filled in the above-mentioned first gap 3011 and gap C3010. For example, Teflon, but not limited to this.

[0049] Please continue to refer to Figure 1As shown, the support ring 400 can be a conductor. The outer annular wall 302 and the inner annular wall 303 are located above the support ring 400 and are concentrically arranged with the outer annular wall 302 and the inner annular wall 303, and are located between the outer annular wall 302 and the extended step 101, so that the outer annular wall 302 is grounded, thereby grounding the plasma confinement ring. In this embodiment, the width of the gap C is 0.5mm to 1mm, and the width of the heat insulation gap is 0.2mm to 2mm. In order to maintain smooth radio frequency transmission and mechanical strength, if the width of the gap C and the heat insulation gap is too small, the two sides of the gap will be too close, which will weaken the heat reduction effect. If the width is too large, it will destroy the radio frequency flow field transmission.

[0050] Example 2

[0051] like Figure 2 As shown, the difference between this embodiment and Embodiment 1 is that the heat insulation gap is a gap A extending axially along the annular sidewall. There can be only one gap, and it does not have an opening structure. For example, a second gap 3012 can be opened in the annular outer sidewall 302. The second gap 3012 is located close to the inner sidewall of the annular outer sidewall 302 and extends axially along the annular outer sidewall 302. The heat of the gas channel wall 300 flows up and down along the inner side of the annular outer sidewall 302, which is divided by the second gap 3012. The annular outer sidewall is divided into an inner part and an outer part by the second gap. Because the cross-sectional area of ​​the inner part of the annular outer sidewall 302 is smaller than that of the outer part, heat propagation is slower there. Therefore, the second gap reduces the rate at which heat is lost from the inner side to the outer side of the annular outer sidewall, thus maintaining the gas channel wall 300 at a higher temperature.

[0052] Based on this embodiment, in order to improve the heat insulation effect of the heat insulation gap and improve the mechanical properties of the horizontal spokes 301 and the annular outer wall 302, heat insulation material can be filled into the second gap 3012 and gap C3010. For example, Teflon, but not limited thereto.

[0053] Therefore, cutting a narrow and high slit longitudinally along the inner side of the outer annular wall of the plasma confinement ring allows the heat flow of the plasma confinement ring to be transmitted downwards only along the narrow thin wall, which can greatly reduce the heat loss of the plasma confinement ring.

[0054] Example 3

[0055] like Figure 3As shown, the difference between this embodiment and Embodiment 1 is that the number of gaps A can be multiple, and they have an opening structure, such as a third gap 3103 and a fourth gap 3104 opened in the annular outer wall 302. The third gap 3103 and the fourth gap 3104 are concentrically arranged and are located close to the inner wall of the annular outer wall 302. The opening of the third gap 3103 is close to the support ring 400, and the opening of the fourth gap 3104 is far away from the support ring 400. The third gap 3103 extends away from the support ring 400 along the axial direction of the annular outer wall 302, and the fourth gap 3104 extends towards the support ring 400 along the axial direction of the annular outer wall 302.

[0056] Based on this embodiment, in order to improve the heat insulation effect of the heat insulation gap and the mechanical properties of the annular outer wall 302, heat insulation material can be filled into the third gap 3103 and the fourth gap 3104. For example, Teflon, but not limited thereto.

[0057] In this embodiment, the third gap 3103 is located closer to the inner wall of the annular outer wall 302 than the fourth gap 3104.

[0058] The third gap provided in this embodiment is located further inward than the fourth gap, and the opening of the third gap 3103 faces downward while the opening of the fourth gap 3104 faces upward. This makes the heat transfer path from the gas channel of the plasma confinement ring to the side wall of the reaction chamber longer, thereby making it easier to reduce the heat loss of the plasma confinement ring, achieving a better heat insulation effect, and further improving the temperature range and distribution uniformity of the plasma confinement ring so that the temperature of the plasma confinement ring reaches the preset temperature and is maintained, thereby achieving the purpose of preventing polymer deposition.

[0059] It is understood that in some other embodiments, such as when the heat insulation gap is provided in the annular inner wall 303, the specific structure is similar to the specific structure of the heat insulation gap described in Embodiments 1 to 3 above, and will not be repeated here.

[0060] In other embodiments, the plasma confinement ring is configured such that the outer annular wall is in contact with the support ring, and the heat insulation gap is set in the outer annular wall, while the inner annular wall is not in contact with the support ring. In this way, there is a gap between the inner annular wall and the support ring, which can also reduce the heat transfer cross-sectional area, thereby reducing the heat loss of the plasma confinement ring.

[0061] Alternatively, the annular inner sidewall is in contact with the support ring, and the heat insulation gap is arranged in the annular inner sidewall, and the annular outer sidewall is not in contact with the support ring; in this way, a gap is formed between the annular outer sidewall and the support ring, and the effect of reducing the heat transfer cross-sectional area is achieved, and the purpose of reducing the heat loss of the plasma confinement ring is achieved.

[0062] Alternatively, the annular outer sidewall and the annular inner sidewall are both in contact with the support ring, and the heat insulation gap is arranged in the annular outer sidewall and the annular inner sidewall, as shown in Figure 6

[0063] When the annular inner sidewall and the annular outer sidewall are both in contact with the support ring, the heat insulation gap is arranged as described in the above embodiments, so as to achieve the purpose of reducing the heat loss of the plasma confinement ring.

[0064] In some other embodiments, as shown in Figure 4 The gas passage wall 300 is a circular ring body 304 arranged between the annular outer sidewall 302 and the annular inner sidewall 303, and the three are concentrically arranged; alternatively, the circular ring body 304 is integrally arranged with the annular outer sidewall 302 and the annular inner sidewall 303; a plurality of through holes (which can be a single row distributed along the circumference of the circular ring body 304, or multiple rows distributed along the circumference of the circular ring body 304) are distributed on the circular ring body 304 in a spaced manner, and each of the through holes constitutes the gas passage wall 300.

[0065] In some embodiments, a fifth gap is further arranged inside the support ring 400.

[0066] Through the fifth gap arranged inside the support ring 400, the effect of reducing the heat transfer cross-sectional area is achieved, and the purpose of reducing the heat loss of the plasma confinement ring is achieved.

[0067] In combination with Figures 1 to 3 ​As shown, in a CCP etching apparatus, the main function of the plasma confinement ring is to confine the plasma 500 within the discharge region using multiple narrow slits (gas channel wall 300) formed by multiple concentric cylindrical rings (nested rings). The cylindrical bodies forming the concentric rings are connected by horizontal spokes 301. To prevent plasma leakage, good contact between the plasma confinement ring and the reaction chamber 100 is generally required to form a relatively large grounding capacitance, thereby reducing the radio frequency voltage of the plasma confinement ring. This requires a relatively thick sidewall (annular outer wall 302) of the plasma confinement ring (10-20 mm). The radio frequency current path from the plasma confinement ring to the grounding ring or support ring (MGR) flows from the plasma 500 along the gas channel and the inner sidewall surface of the annular outer wall 302, as well as the contact surface between the annular outer wall 302 and the support ring, towards ground. The radio frequency current is determined by the loop impedance, while the impedance from the plasma confinement ring to the MGR depends on the capacitance between them, which is determined by the contact area and slit height between the plasma confinement ring and the MGR.

[0068] Meanwhile, as plasma 500 flows through the plasma confinement ring, it transfers heat from the gas to the plasma confinement ring. The cooling (heat flow) channels of the plasma confinement ring (such as...) Figures 1 to 4 (As shown in any of the figures): The heat is mainly collected by the concentric rings of the plasma confinement ring, and conducted to the sidewalls (outer annular wall 302) of the plasma confinement ring through the horizontal spokes 301.

[0069] Then, the heat is conducted to the MGR and the sidewalls of the reaction chamber through the gap between the plasma confinement ring and the MGR. According to the principle of heat conduction, the temperature T1 of the plasma confinement ring can be expressed as:

[0070]

[0071] Where T0 is the temperature of the reaction chamber sidewall, Q is the heat deposited by the plasma gas onto the plasma confinement ring, k is the thermal conductivity (of the material or medium), d is the heat transfer distance from the plasma confinement ring to the MGR, and S is the thermally conductive area. Since the plasma confinement ring is generally made of aluminum or aluminum alloy, its sidewalls are relatively thick (10–20 mm), and its thermal conductivity is high, resulting in a very small internal temperature difference. Therefore, the thermal resistance from the plasma confinement ring to the chamber sidewall is mainly determined by the interface between the plasma confinement ring and the MGR. Because existing designs have a very small d (<0.5 mm, representing the gap between the plasma confinement ring and the MGR) and a relatively large S (bottom area of ​​the plasma confinement ring), the plasma confinement ring has a relatively good cooling effect, resulting in a low temperature (typically less than 80°C), which makes it prone to polymer buildup.

[0072] Figure 1The method for heat insulation and temperature increase of the plasma confinement ring and its temperature distribution uniformity is shown in the above embodiment 1. A deep slot (0.5-1mm wide) is cut on the horizontal spoke of the plasma confinement ring near the side wall to limit the heat conduction from the spoke to the side wall; a 0.2-2mm high transverse deep slot is cut on the lower side wall of the plasma confinement ring along the circumferential direction, leaving a wall thickness of 0.5-2mm, so that d increases and S decreases, thereby forming a thermal resistance in the body of the side wall of the plasma confinement ring and increasing a large-area thermal insulation layer. In this way, the heat of the plasma confinement ring can only flow to the side wall of the reaction chamber through the remaining thin wall on the inside, thereby greatly reducing the heat transfer from the plasma confinement ring to the side wall (indicated by the arrow direction). By optimizing the parameters of d and S, the heat transfer can be reduced by more than 90%, thereby increasing the temperature of the plasma confinement ring to above the melting point of the polymer (150-200℃), preventing the accumulation of the polymer on the plasma confinement ring. Moreover, due to the increase of the thermal resistance in the horizontal spoke, the temperature distribution uniformity of the concentric rings of the plasma confinement ring can also be improved. Figure 1

[0073] In addition, due to the skin effect of the radio frequency current, when the radio frequency frequency is >100kHz, the distribution depth of the radio frequency current on the plasma confinement ring (made of aluminum or its alloy) is <0.3mm, and the radio frequency current only flows through the inner surface and bottom surface of the side wall of the plasma confinement ring. Therefore, the heat insulation slot proposed in this embodiment does not affect the radio frequency current channel of the plasma confinement ring to the MGR, and thus does not affect the plasma distribution in the reaction chamber.

[0074] On the other hand, as Figure 5 shown, this embodiment also provides a plasma processing device, which comprises: a reaction chamber, wherein a pedestal 110 for carrying a substrate is arranged;

[0075] a gas injection device 120 for delivering a reaction gas into the reaction chamber;

[0076] a plasma confinement ring as described above, which is arranged around the periphery of the pedestal 110, and is used to discharge the reaction gas in the reaction chamber.

[0077] This embodiment solves the problem that the gas extraction channel (gas channel or annular channel) is narrowed due to the low temperature of the plasma confinement ring, which affects the gas extraction rate and even blocks the gas extraction channel, thereby affecting the high aspect ratio etching process.

[0078] It can be understood that in some other embodiments, the above-mentioned heat insulation slot or plasma confinement ring is also applicable to an ICP (inductively coupled plasma reaction device) chamber. In another aspect, this embodiment also provides a method for processing a semiconductor using the above-mentioned plasma processing device, which comprises: ​

[0079] delivering a reaction gas into the reaction chamber;

[0080] ionizing the reaction gas into a plasma and etching a semiconductor substrate located on the susceptor in the reaction chamber;

[0081] During etching, the surface of the plasma confinement ring exposed to the plasma reaches a temperature that prevents polymer deposited on the surface during etching.

[0082] The embodiment solves the problem that the temperature of the plasma confinement ring is low, the gas extraction channel (gas channel or annular channel) is narrowed, the gas extraction rate is affected, and even the gas extraction channel is blocked, thereby affecting the high aspect ratio etching process.

[0083] In summary, the plasma confinement ring provided by the embodiment slows down the heat transfer from the gas channel to the sidewall of the reaction chamber by providing a heat insulation gap on the annular sidewall. That is, the provision of the heat insulation gap is equivalent to adding a large-area heat insulation layer on the annular sidewall. In this way, the heat of the plasma confinement ring can only flow to the sidewall of the reaction chamber through the residual thin wall on the inner side of the annular sidewall, thereby greatly reducing the heat transfer from the plasma confinement ring to the sidewall, and further enabling the gas channel to maintain a temperature and improve its uniformity, thereby preventing polymer deposition.

[0084] The heat insulation gap is annular, that is, the first gap to the fourth gap are annular. Due to the skin effect of the radio frequency current, when the radio frequency frequency is >100 kHz, the distribution depth of the radio frequency current on the plasma confinement ring (material is aluminum or its alloy) is <0.3 mm, and the radio frequency current only flows through the inner surface and bottom surface of the sidewall of the plasma confinement ring. Therefore, the heat insulation gap provided by the present application will not affect the radio frequency current channel from the plasma confinement ring to the MGR (support ring), and thus will not affect the plasma distribution in the reaction chamber.

[0085] The third gap is closer to the inner side than the fourth gap, thereby making the heat transfer path from the gas channel of the plasma confinement ring to the sidewall of the reaction chamber longer, thereby more easily enabling the temperature of the plasma confinement ring to reach a preset temperature and be maintained, thereby achieving the purpose of preventing polymer deposition.

[0086] It is to be understood that the terminology used herein such as first and second, and the like, is only intended to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0087] In the description of the application, it is to be understood that the orientation or positional relationship indicated by the terms "center", "height", "thickness", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specified and limited.

[0088] In the description of the application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0089] In the present application, unless otherwise explicitly specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "above" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. "Below", "below" and "below" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0090] While the application has been described in detail and with reference to specific preferred embodiments thereof, it will be apparent to one skilled in the art that various modifications and alternatives can be employed without departing from the spirit and scope of the application. Accordingly, the scope of the application should be determined by the appended claims and their equivalents.

Claims

1. A plasma confinement ring disposed within the reaction chamber of a plasma processing device, the plasma confinement ring comprising an annular sidewall and a gas channel wall fixedly connected to the annular sidewall; the annular sidewall is placed on a support ring, the support ring being fixed to the sidewall of the reaction chamber, characterized in that, Also includes: Insulating gaps are provided in the annular sidewall to slow down the transfer of heat from the gas channel wall to the sidewall of the reaction chamber; The annular sidewall includes an inner annular sidewall and an outer annular sidewall, the gas channel wall is located between the inner annular sidewall and the outer annular sidewall, and the heat insulation gap is located in the inner annular sidewall and / or the outer annular sidewall. The gas channel wall is composed of multiple concentric nested rings of different diameters. The multiple nested rings are fixedly connected to the annular sidewall by spokes located at their lower parts. A gap C extending axially along the annular sidewall is provided at the connection between the spokes and the inner and / or outer sidewall of the annular sidewall.

2. The plasma confinement ring as described in claim 1, characterized in that, The heat insulation gap includes: a gap A extending axially along the annular sidewall.

3. The plasma confinement ring as described in claim 2, characterized in that, The number of slits A is at least two constituting a slit group, wherein two of the slits A have openings on the annular sidewall surface, and the two openings are oriented in opposite directions.

4. The plasma confinement ring as described in claim 2, characterized in that, The gap A is located close to the wall of the gas channel.

5. The plasma confinement ring as described in claim 1, characterized in that, The heat insulation gap includes a gap B extending radially along the annular sidewall.

6. The plasma confinement ring as described in claim 5, characterized in that, The number of slits B is at least two constituting a slit group, wherein two of the slits B have openings on the annular sidewall surface, and the two openings are oriented in opposite directions.

7. The plasma confinement ring as described in claim 5, characterized in that, The gap B is located near the support ring.

8. The plasma confinement ring as described in claim 1, characterized in that, The width of the insulation gap is 0.2mm to 2mm.

9. The plasma confinement ring as described in claim 1, characterized in that, The width of the gap C is 0.5mm to 1mm.

10. The plasma confinement ring as described in claim 1, characterized in that, The gas channel wall is composed of an annular structure with multiple through holes.

11. The plasma confinement ring as described in claim 10, characterized in that, The heat insulation gap is annular, and a gap C along the axial direction of the annular sidewall is provided at the connection between the annular body and the inner and / or outer sidewall of the annular body.

12. The plasma confinement ring as described in claim 1, characterized in that, The heat insulation gap is circular.

13. The plasma confinement ring as described in claim 1, characterized in that, The support ring is a conductor, which grounds the plasma confinement ring. The support ring has a slit extending radially along the support ring.

14. The plasma confinement ring as described in claim 1, characterized in that, The heat insulation gaps are filled with heat insulation material.

15. The plasma confinement ring as described in claim 1, characterized in that, The annular inner wall, annular outer wall, and gas channel wall are designed as a single unit.

16. A plasma processing device, characterized in that, include: A reaction chamber, wherein a base for supporting the substrate is disposed within the reaction chamber; A gas injection device is used to deliver reaction gas into the reaction chamber; The plasma confinement ring as described in any one of claims 1-15 is disposed around the periphery of the base.

17. A method for processing semiconductors using the plasma processing apparatus of claim 16, characterized in that, include: Delivery of reaction gas into the reaction chamber; The reactive gas is ionized into plasma and etched onto the semiconductor substrate located on the base in the reaction chamber; During etching, the heat transfer from the gas channel wall to the side wall of the reaction chamber is slowed down through the heat insulation gap, so that the gas channel wall is kept at a temperature that prevents the deposition of etched polymer.

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