CN219286334U

CN219286334U - Movable ring and plasma processing equipment

Info

Publication number: CN219286334U
Application number: CN202223554194.9U
Authority: CN
Inventors: 徐朝阳; 刘清松; 朱永成
Original assignee: Advanced Micro Fabrication Equipment Inc Shanghai
Current assignee: Advanced Micro Fabrication Equipment Inc Shanghai
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-06-30
Anticipated expiration: 2032-12-29

Abstract

The utility model discloses a moving ring and plasma processing equipment, the moving ring comprises: a restriction portion for restricting plasma; the limiting part comprises an inner side surface and an outer side surface which are opposite, and the inner side surface of the limiting part is in contact with the plasma; the inner side surface of the first end of the limiting part is provided with a first thickness along the normal direction to the outer side surface of the first end of the limiting part, the inner side surface of the second end of the limiting part is provided with a second thickness along the normal direction to the outer side surface of the second end of the limiting part, and the first thickness is smaller than or equal to the second thickness; the plurality of protruding parts are arranged on the outer side surface of the limiting part at intervals along the circumferential direction of the limiting part; each protruding part is connected with the driving mechanism and used for driving the limiting part to move between the high position and the low position. On the premise of meeting the functions and the installation requirements of the movable ring, the utility model ensures that the whole weight of the movable ring is lighter, thereby ensuring that the temperature of the movable ring is higher under the same temperature environment or when the same heat is absorbed, and avoiding the polymer formed by the deposition of reaction byproducts on the movable ring.

Description

Movable ring and plasma processing equipment

Technical Field

The utility model relates to the technical field of semiconductors, in particular to a movable ring and plasma processing equipment.

Background

In the plasma processing equipment, the moving ring has the function of moving up and down, and when a wafer is required to be transferred into the cavity or taken out from the cavity, the moving ring can be moved up to a high position; when in the etching process, the movable ring can be moved down to a low position, thereby playing a role in confining plasma. However, at present, the movable ring is generally made of materials (such as quartz, ceramic, etc.) resistant to plasma corrosion, and the edges of the movable ring are mostly in a thick and heavy structure, so that the weight of the movable ring is large, and in the etching process, the temperature of the movable ring is relatively low relative to the rest of parts in the reaction cavity, and polymer is easily formed by reaction byproducts generated in the etching process and deposited on the surface of the movable ring. When the polymer is accumulated to a certain degree, the polymer can fall off from the surface of the movable ring and splash onto the wafer, so that the wafer is polluted, and the wafer preparation yield is reduced. Therefore, it is necessary to adjust the structure of the movable ring.

Disclosure of Invention

The utility model aims to provide a movable ring and plasma processing equipment, which can ensure that the whole weight of the movable ring is lighter on the premise of meeting the functions and the installation requirements of the movable ring, and can ensure that the temperature of the movable ring is higher under the same temperature environment or when the same heat is absorbed, so that the polymer formed by deposition of reaction byproducts on the movable ring is avoided.

In order to achieve the above purpose, the present utility model is realized by the following technical scheme:

a motion ring for a reaction chamber of a plasma processing apparatus, comprising:

a restriction portion for restricting plasma; the limiting part comprises an inner side surface and an outer side surface which are opposite, and the inner side surface of the limiting part is in contact with plasma; the limiting part further comprises a first end and a second end which are opposite, and the inner diameter of the first end of the limiting part is smaller than that of the second end of the limiting part; the inner side surface of the first end of the limiting part is provided with a first thickness along the normal direction of the inner side surface to the outer side surface of the first end of the limiting part, the inner side surface of the second end of the limiting part is provided with a second thickness along the normal direction of the inner side surface to the outer side surface of the second end of the limiting part, and the first thickness is smaller than or equal to the second thickness; and

the plurality of protruding parts are arranged on the outer side surface of the limiting part at intervals along the circumferential direction of the limiting part; and each protruding part is connected with a driving mechanism outside the reaction cavity and used for driving the limiting part to move between a high position and a low position.

Optionally, the limiting part includes: an annular member comprising opposing annular member top and annular member bottom ends; and an upper edge extending upward in an axial direction of the annular member tip.

Optionally, the inner diameter of the top end of the annular member is smaller than the inner diameter of the bottom end of the annular member.

Optionally, an included angle between the upper edge and the annular component is 120-150 degrees.

Optionally, the thickness between the inner side surface of the upper edge and the outer side surface of the upper edge along the normal direction is 3 mm-8 mm.

Optionally, the thickness between the inner side surface of the annular part along the normal direction thereof and the outer side surface of the annular part is greater than or equal to the thickness between the inner side surface of the upper edge along the normal direction thereof and the outer side surface of the upper edge.

Optionally, the limiting part further includes: a lower edge extending axially downwardly along the bottom end of the annular member.

Optionally, the inner side surface of the lower edge is parallel to the inner side surface of the upper edge.

Optionally, the thickness between the inner side surface of the lower edge along the normal direction thereof and the outer side surface of the lower edge is greater than or equal to the thickness between the inner side surface of the upper edge along the normal direction thereof and the outer side surface of the upper edge.

Optionally, the protruding portion is connected with the driving mechanism through a connecting component, and a connecting hole matched with the connecting component is formed in the protruding portion.

Optionally, a heater is further arranged on the outer side surface of the limiting part, and is used for heating the limiting part.

Optionally, a casing is further sleeved on the outer side surface of the limiting part, so as to prevent electric spark from being generated between the limiting part and the cavity wall of the reaction cavity.

Optionally, the material of the limiting part is quartz or ceramic.

In another aspect, the present utility model also provides a plasma processing apparatus, comprising: a reaction chamber; a base arranged at the bottom of the reaction chamber; the spray header is arranged at the top of the interior of the reaction cavity; and a moving ring as described above, with the moving ring disposed around a reaction region between the showerhead and the susceptor.

Compared with the prior art, the utility model has at least one of the following advantages:

the utility model provides a moving ring and plasma processing equipment, wherein the moving ring comprises a limiting part and a protruding part, the limiting part is used for limiting plasma, and the limiting part comprises an inner side surface and an outer side surface which are opposite, wherein the inner side surface of the limiting part is in contact with the plasma; the protruding parts are arranged on the outer side face of the limiting part at intervals along the circumferential direction of the limiting part, and the protruding parts are connected with a driving mechanism outside the reaction cavity so as to drive the limiting part to move between a high position and a low position, and the up-down movement function of the moving ring is realized.

According to the utility model, the inner side surface of the first end of the limiting part is provided with the first thickness along the normal direction of the inner side surface to the outer side surface of the first end of the limiting part, the inner side surface of the second end of the limiting part is provided with the second thickness along the normal direction of the inner side surface to the outer side surface of the second end of the limiting part, and the first thickness is smaller than or equal to the second thickness, so that the wall of the limiting part is thinner, the weight of the limiting part is lighter on the premise of meeting the function and installation requirements of the limiting part, and the whole weight of the moving ring is lighter, so that the temperature of the moving ring is higher and the gasification temperature of reaction byproducts is quickly reached under the same temperature environment or when the same heat is absorbed, the reaction byproducts are prevented from depositing and forming polymers on the inner side surface of the limiting part, the risk of introducing particle impurities is effectively reduced, and the preparation yield of wafers is improved.

According to the utility model, under the condition that the whole weight of the movable ring is light, the movable ring can be heated to the gasification temperature of the reaction byproducts by utilizing the heat generated in the process that the process gas is ionized into the plasma and the process that the plasma etches the wafer, so that the temperature of the movable ring can reach the use requirement without additionally arranging a complex heating device, and the reaction byproducts are prevented from depositing on the inner side surface of the limiting part to form polymers.

The utility model can also be sleeved with the shell on the outer side surface of the limiting part so as to prevent electric sparks from being generated between the limiting part and the cavity wall of the reaction cavity, thereby avoiding the interference to the radio frequency path of the process.

Drawings

Fig. 1 is a schematic view of a plasma processing apparatus according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of a moving ring according to an embodiment of the present utility model;

FIG. 3 is a schematic cross-sectional view of a moving ring along A-A according to an embodiment of the present utility model;

FIG. 4 is a schematic cross-sectional view of a moving ring along the direction B-B according to an embodiment of the present utility model.

Detailed Description

The following provides a further detailed description of a motion ring and a plasma processing apparatus according to the present utility model, with reference to the accompanying drawings and detailed description. The advantages and features of the present utility model will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for the purpose of facilitating and clearly aiding in the description of embodiments of the utility model. For a better understanding of the utility model with objects, features and advantages, refer to the drawings. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that any modifications, changes in the proportions, or adjustments of the sizes of structures, proportions, or otherwise, used in the practice of the utility model, are included in the spirit and scope of the utility model which is otherwise, without departing from the spirit or essential characteristics thereof.

It is noted that relational terms such as first and second, and the like are used solely 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 variation 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 may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Referring to fig. 1 to 4, the present embodiment provides a moving ring for a reaction chamber 110 of a plasma processing apparatus, comprising: a confinement portion 210 for confining the plasma; the limiting part 210 includes opposite inner and outer sides, and the inner side of the limiting part 210 contacts with plasma; the limiting portion 210 further includes a first end and a second end opposite to each other, and an inner diameter of the first end of the limiting portion 210 is smaller than an inner diameter of the second end of the limiting portion 210; and the inner side surface of the first end of the limiting part 210 has a first thickness along the normal direction thereof to the outer side surface of the first end of the limiting part 210, and the inner side surface of the second end of the limiting part 210 has a second thickness along the normal direction thereof to the outer side surface of the second end of the limiting part 210, wherein the first thickness is less than or equal to the second thickness; and a plurality of protruding portions 220 disposed on an outer side surface of the limiting portion 210 at intervals along a circumferential direction of the limiting portion 210; and each of the protruding portions 220 is connected to a driving mechanism outside the reaction chamber 110, for driving the limiting portion 210 to move between a high position and a low position.

Specifically, in this embodiment, a susceptor 120 for carrying the wafer 100 and a confinement ring 140 disposed around the susceptor 120 are disposed at the bottom of the reaction chamber 110, and a showerhead 130 opposite to the susceptor 120 is disposed at the top of the reaction chamber 110. More specifically, the reaction chamber 110 includes a chamber 112 and a top cover 111 disposed on top of the chamber 112; the base 120 may be disposed inside the cavity 112, the showerhead 130 may be fixed on a lower end surface of the top cover 111, that is, an end surface near the base 120, and the showerhead 130 may be connected with a gas supply device (not shown in the figure) outside the reaction chamber 110, so as to introduce a process gas into the reaction region 200 between the showerhead 130 and the base 120. Meanwhile, the showerhead 130 may also be used as an upper electrode of the reaction chamber 110, the susceptor 120 may also be used as a lower electrode of the reaction chamber 110, and at least one rf power source is applied to the lower electrode to generate an rf electric field between the upper electrode and the lower electrode, so as to ionize the process gas in the reaction region 200 into plasma and perform etching process on the wafer 100, but the utility model is not limited thereto.

Specifically, in the present embodiment, the confinement portion 210 may be disposed around the reaction region 200 to confine the plasma in the reaction region 200, and the inner side surface of the confinement portion 210 is close to the reaction region 200. The protruding portion 220 fixed on the limiting portion 210 is connected to the driving mechanism (not shown) through a connecting member 221, so that the driving mechanism can drive the protruding portion 220 to move up and down, thereby driving the limiting portion 210 to move between the high position and the low position along a direction perpendicular to the surface of the wafer 100. More specifically, the side wall of the cavity 112 is provided with a wafer transfer port 113, and the high position is located above the wafer transfer port 113, so that the wafer can be taken and placed through the wafer transfer port 113 when the limiting part 210 rises to the high position; when the limiting part 210 is lowered to the low position, a vertical interval between the limiting part 210 and the confinement ring 140 is 0.5mm to 0.8mm, preferably, a vertical interval is 0.7mm, so that the limiting part 210 and the confinement ring 140 limit the plasma in the reaction region 200 together to avoid leakage of the plasma to the non-reaction region and damage of components of the non-reaction region. Optionally, the protruding portion 220 is integrally provided with the limiting portion 210; the number of the protruding parts 220 is 3, and the protruding parts 220 are provided with connection holes 2201 matching with the connection parts 221. Preferably, the connecting member 221 is a threaded rod, and the connecting hole 2201 is a threaded hole, but the utility model is not limited thereto.

Specifically, reaction byproducts are generated during the process of ionizing the process gas into the plasma and during the etching of the wafer by the plasma, and the confinement portion 210 disposed around the reaction region 200 is directly contacted with the reaction byproducts, which results in the reaction byproducts being easily formed into polymers and continuously adhered to the inner side surface of the confinement portion 210. In this embodiment, the first end of the limiting portion 210, that is, the end near the showerhead 130 has the first thickness, the second end of the limiting portion 210, that is, the end far from the showerhead 130 has the second thickness, and the first thickness is smaller than or equal to the second thickness, so that the wall of the limiting portion 210 is thinner, and by providing a plurality of protruding portions 220 for mounting and fixing on the outer side surface of the limiting portion 210, the weight of the limiting portion 210 is lighter on the premise of meeting the function and mounting requirements of the limiting portion 210, and further the overall weight of the moving ring is lighter, so that the temperature of the moving ring is higher and reaches the gasification temperature of reaction byproducts rapidly under the same temperature environment or when the same heat is absorbed, thereby avoiding the deposition of reaction byproducts on the inner side surface of the limiting portion 210, effectively reducing the risk of introducing particle impurities and improving the wafer preparation yield, but the utility model is not limited thereto.

More specifically, heat is generated during the process of ionizing the process gas into the plasma and during the process of etching the wafer by the plasma, and under the condition that the overall weight of the movable ring is light, the heat generated during the process can heat the movable ring to the gasification temperature of the reaction byproducts, so that the temperature of the movable ring can reach the use requirement without additionally arranging a complex heating device, and further, the deposition of the reaction byproducts on the inner side surface of the limiting part 210 is avoided. In addition, in some embodiments, a heater (not shown in the drawings) is further disposed on an outer side surface of the limiting portion 210, so as to heat the limiting portion 210 to further ensure that the temperature of the moving ring reaches the operating requirement, but the utility model is not limited thereto.

Specifically, in this embodiment, a housing (not shown in the drawing) is further sleeved on the outer side surface of the limiting portion 210, so as to prevent electric spark from being generated between the limiting portion 210 and the wall of the reaction chamber 110, thereby avoiding interference to the rf path of the process. More specifically, the housing and the limiting portion 210 may be fixedly connected by a plurality of connecting rods, so that a direct contact area between the housing and the limiting portion 210 is smaller, and heat on the limiting portion 210 is prevented from being transferred to the housing as much as possible. Optionally, the boss 220 is located within or through the housing; and when the protruding portion 220 is located in the housing, the connecting member 221 penetrates through the housing and is fixedly connected with the protruding portion 220. The material of the housing is the same as that of the limiting part 210, and the material of the limiting part 210 is quartz or ceramic. Optionally, the material of the limiting portion 210 is synthetic quartz, but the utility model is not limited thereto.

Referring to fig. 1 to 4, the limiting portion 210 includes: an annular component 2101 comprising opposing annular component top and annular component bottom ends; and an upper edge 2102 extending in an axial direction of the top end of the ring-shaped member 2101 toward a direction close to the shower head 130 (i.e., upward); and the annular member 2101 is disposed around the reaction region 200, the upper edge 2102 is disposed around the showerhead 130, and in this case, the annular member 2101 and the inner side surface of the upper edge 2102 together form the inner side surface of the restriction 210, and the annular member 2101 and the outer side surface of the upper edge 2102 together form the outer side surface of the restriction 210.

Specifically, in this embodiment, the top end of the annular component 2101 is close to the showerhead 130, the bottom end of the annular component 2101 is far away from the showerhead 130, and the inner diameter of the top end of the annular component 2101 is smaller than the inner diameter of the bottom end of the annular component 2102, that is, the annular component 2101 is a cone ring. More specifically, the bottom end of the ring member 2101 is located above the confinement ring 140 and aligned with the radially outer edge of the confinement ring 140, so that the ring member 2101 and the confinement ring 140 can confine the plasma in the reaction region 200 without affecting the removal of the reaction byproducts in the reaction region 200 by the exhaust pump through the through holes in the body confinement ring 140, and thus, the exhaust is outside the reaction chamber 110, but the utility model is not limited thereto.

Specifically, in this embodiment, the top end of the annular component 2101 is located radially outside the showerhead 130, and the upper edge 2102 is fixedly connected to the top end of the annular component 2101; the upper edge 2102 is cylindrical, has an inner side surface parallel to the outer edge of the showerhead 130, and has a gap between the inner side surface of the upper edge 2102 and the outer edge of the showerhead 130 as small as possible without affecting the up-down movement of the upper edge 2102, so as to prevent a large amount of plasma and reaction byproducts in the reaction region 200 from escaping from the gap to a non-reaction region. More specifically, the connection between the inner side surface of the upper edge 2102 and the inner side surface of the annular component 2101 is provided with a first arc chamfer, so that the transition between the inner side surface of the upper edge 2102 and the inner side surface of the annular component 2101 is smooth, and therefore no interference is caused to the flow direction of the plasma. Optionally, the upper edge 2102 may be angled from 120 degrees to 150 degrees from the annular member 2101; the thickness between the inner side surface of the upper edge 2102 and the outer side surface of the upper edge 2102 in the normal direction thereof is 3mm to 8mm, and the thickness between the inner side surface of the ring-shaped member 2101 and the outer side surface of the ring-shaped member 2101 in the normal direction thereof is equal to or greater than the thickness between the inner side surface of the upper edge 2102 and the outer side surface of the upper edge 2102 in the normal direction thereof, at this time, the thickness between the inner side surface of the upper edge 2102 and the outer side surface of the upper edge 2102 in the normal direction thereof may be the first thickness, and the thickness between the inner side surface of the ring-shaped member 2101 and the outer side surface of the ring-shaped member 2101 in the normal direction thereof may be the second thickness. Preferably, the upper edge 2102 is angled at 135 degrees from the annular member 2101; the thickness between the inner side surface of the upper edge 2102 and the outer side surface of the upper edge 2102 in the normal direction thereof is 5mm, and the thickness between the inner side surface of the ring-shaped member 2101 and the outer side surface of the ring-shaped member 2101 in the normal direction thereof is also 5mm. Optionally, the boss 220 is disposed on an outer side surface of the ring-shaped member 2101 and/or the upper edge 2102, and the heater is disposed on an outer side surface of the ring-shaped member 2101, but the utility model is not limited thereto.

Referring to fig. 1 to 4, the limiting portion 210 further includes: a lower edge 2103 extending along the axial direction of the bottom end of the annular member 2101 in a direction away from the shower head 130 (i.e., downward), and the lower edge 2103 is disposed around the reaction region 200 and above the confinement rings 140, where the inner side surfaces of the annular member 2101, the upper edge 2102 and the lower edge 2103 together form the inner side surface of the confinement portion 210, and the outer side surfaces of the annular member 2101, the upper edge 2102 and the lower edge 2103 together form the outer side surface of the confinement portion 210.

Specifically, in this embodiment, the lower edge 2103 is fixedly connected to the bottom end of the annular component 2101, and the inner side surface of the lower edge 2103 is parallel to the inner side surface of the upper edge 2102, that is, the included angle between the lower edge 2103 and the annular component 2101 and the included angle between the upper edge 2102 and the annular component 2101 are the same, and optionally, the upper edge 2102 and the lower edge 2103 are cylindrical, and extend upwards and downwards for a distance along the axial direction of the annular component 2101. The provision of the lower edge 2103 may increase the internal volume of the moving ring, thereby providing the ability to contain plasma inside the moving ring. More specifically, the connection between the inner side surface of the annular component 2101 and the inner side surface of the lower edge 2103 is provided with a second arc chamfer, so that the transition between the inner side surface of the annular component 2101 and the inner side surface of the lower edge 2103 is smooth, and the flow direction of the plasma is not disturbed. Optionally, the thickness between the inner side surface of the lower edge 2103 and the outer side surface of the lower edge 2103 along the normal direction thereof is greater than or equal to the thickness between the inner side surface of the upper edge 2102 and the outer side surface of the upper edge 2102 along the normal direction thereof, at this time, the thickness between the inner side surface of the upper edge 2102 and the outer side surface of the upper edge 2102 along the normal direction thereof may be the first thickness, and the thickness between the inner side surface of the lower edge 2103 and the outer side surface of the lower edge 2103 along the normal direction thereof may be the second thickness. Preferably, the thickness between the inner side surface of the lower edge 2103 and the outer side surface of the lower edge 2103 along the normal direction thereof is 5 mm-15 mm. Optionally, the ring-shaped member 2101, the upper edge 2102 and the lower edge 2103 are integrally provided, but the utility model is not limited thereto.

On the other hand, as shown in fig. 1, the present embodiment also provides a plasma processing apparatus including: a reaction chamber 110; a susceptor 120 disposed at the inner bottom of the reaction chamber 110; a showerhead 130 disposed at an inner top of the reaction chamber 110, the showerhead 130 being disposed opposite to the susceptor 120; a confinement ring 140 disposed around the base 120; and a moving ring as described above, and disposed around the reaction region 200 between the showerhead 130 and the susceptor 120.

In summary, the present utility model provides a moving ring and a plasma processing apparatus, the moving ring includes a limiting portion and a protruding portion, the limiting portion is used for limiting plasma, and the limiting portion includes an opposite inner side surface and an opposite outer side surface, wherein the inner side surface of the limiting portion contacts with the plasma; the protruding parts are arranged on the outer side face of the limiting part at intervals along the circumferential direction of the limiting part, and the protruding parts are connected with a driving mechanism outside the reaction cavity so as to drive the limiting part to move between a high position and a low position, so that the moving ring has the function of moving up and down. In this embodiment, the inner side surface of the first end of the limiting portion has a first thickness along the normal direction thereof to the outer side surface of the first end of the limiting portion, the inner side surface of the second end of the limiting portion has a second thickness along the normal direction thereof to the outer side surface of the second end of the limiting portion, and the first thickness is smaller than or equal to the second thickness, so that the wall of the limiting portion is thinner, and the weight of the limiting portion is lighter under the premise of meeting the function and installation requirements of the limiting portion, so that the overall weight of the moving ring is lighter, and then the temperature of the moving ring is higher and the gasification temperature of reaction byproducts is quickly reached under the same temperature environment or when the same heat is absorbed, thereby avoiding the reaction byproducts from depositing and forming polymers on the inner side surface of the moving ring, effectively reducing the risk of introducing particle impurities and improving the preparation yield of wafers. In addition, under the condition that the whole weight of the movable ring is lighter, the movable ring can be heated to the gasification temperature of the reaction byproducts by utilizing heat generated in the process that the process gas is ionized into plasma and in the process that the plasma etches the wafer, so that the temperature of the movable ring can reach the use requirement on the premise of not additionally arranging a complex heating device, and further, the reaction byproducts are prevented from depositing on the inner side surface of the limiting part to form polymers.

While the present utility model has been described in detail through the foregoing description of the preferred embodiment, it should be understood that the foregoing description is not to be considered as limiting the utility model. Many modifications and substitutions of the present utility model will become apparent to those of ordinary skill in the art upon reading the foregoing. Accordingly, the scope of the utility model should be limited only by the attached claims.

Claims

1. A motion ring for a reaction chamber of a plasma processing apparatus, comprising:

2. The shift ring of claim 1, wherein the limiting portion comprises: an annular member comprising opposing annular member top and annular member bottom ends; and an upper edge extending upward in an axial direction of the annular member tip.

3. The shift ring of claim 2, wherein an inner diameter of a top end of the annular member is smaller than an inner diameter of a bottom end of the annular member.

4. The shift ring of claim 2, wherein the upper edge is angled from 120 degrees to 150 degrees from the annular member.

5. The shift ring of claim 2, wherein a thickness between an inner side surface of the upper rim and an outer side surface of the upper rim along a normal direction thereof is 3mm to 8mm.

6. The shift ring of claim 5, wherein a thickness between an inner side surface of the ring member in a normal direction thereof to an outer side surface of the ring member is equal to or greater than a thickness between an inner side surface of the upper rim in a normal direction thereof to an outer side surface of the upper rim.

7. The shift ring of claim 2, wherein the limiting portion further comprises: a lower edge extending axially downwardly along the bottom end of the annular member.

8. The shift ring of claim 7, wherein an inner side of the lower rim is parallel to an inner side of the upper rim.

9. The shift ring of claim 7, wherein a thickness between an inner side surface of the lower rim along a normal direction thereof to an outer side surface of the lower rim is equal to or greater than a thickness between an inner side surface of the upper rim along a normal direction thereof to an outer side surface of the upper rim.

10. The shift ring of claim 1, wherein the boss is connected to the driving mechanism by a connecting member, and the boss is provided with a connecting hole matching the connecting member.

11. The shift ring as claimed in claim 1, wherein a heater is further provided on an outer side surface of the restriction portion for heating the restriction portion.

12. The shift ring of claim 1, wherein an outer case is further provided on an outer side surface of the restriction portion for preventing spark from occurring between the restriction portion and a wall of the reaction chamber.

13. The shift ring of claim 1, wherein the material of the limiting portion is quartz or ceramic.

14. A plasma processing apparatus, comprising: a reaction chamber; a base arranged at the bottom of the reaction chamber; the spray header is arranged at the top of the interior of the reaction cavity; and a moving ring as claimed in any one of claims 1 to 13, wherein the moving ring is disposed around a reaction region between the showerhead and the susceptor.