A highly controllable edge ring assembly and processing chamber structure for wafer etching

Abstract

The present invention discloses a highly controllable edge ring assembly and processing chamber structure for wafer etching. The highly controllable edge ring assembly is disposed around an electrostatic chuck and includes a first edge ring, a second edge ring, and a third edge ring. The first edge ring has a first magnetic device and a first inwardly recessed groove and / or a first downwardly extending protrusion at its bottom. The second edge ring is disposed below the first edge ring and has a second magnetic device and an upwardly extending second protrusion and / or an inwardly recessed groove at its top. The contact surfaces of the first and second magnetic devices have the same polarity, i.e., they repel each other, and the magnetic force is adjustable to enable the first edge ring to move upward. The third edge ring is disposed inside the first and second edge rings, with the inner side of the third edge ring connected to the electrostatic chuck and the top of the third edge ring parallel to the top of the electrostatic chuck. The present invention can eliminate process variations that occur during etching and improve product qualification rates.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a highly controllable edge ring component and a processing chamber structure for wafer etching. Background Art

[0002] During the semiconductor etching process, the wafer needs to be secured to the bottom of the process chamber. Early wafers were physically secured using mechanical clamps. As the manufacturing process progressed, this was gradually replaced by an ESC (Electrostatic Chuck), which also serves as the bottom electrode. The basic principle of an electrostatic chuck is the mutual attraction between oppositely charged charges. Specifically, the Coulomb force between the wafer and electrons stabilizes the wafer on the electrode.

[0003] In semiconductor etching equipment using electrostatic chucks, an edge ring made of a material with similar properties to the wafer is used to minimize the difference in etch rate between the edge and center of the wafer. However, during the etching process, as the edge ring is etched, the etch rate becomes different, and the process difference occurs between the circular edge and the center area of ​​the wafer. In order to eliminate this difference and shorten the PM cycle (productive maintenance cycle) of the process chamber, losses can be avoided by increasing the number of PMs and replacing processing parts, but this will lead to increased labor costs and hardware costs.

[0004] like Figure 1 As shown, the etching process causes the upper surface of the edge ring 100 to be etched. As the upper surface of the edge ring 100 is etched, the etching amount at the edge and center of the wafer 300 becomes different, thereby causing process distribution differences.

[0005] like Figure 2 As shown, in order to slightly adjust the height of the etched edge ring 100, the lift pin on the cylindrical base is driven to fine-tune the edge ring 100 upward. Since the lift pin and the cylindrical base are connected to the outside, this method is likely to cause chamber leakage. Summary of the Invention

[0006] In order to solve the above problems, the present invention proposes a highly controllable edge ring assembly and processing chamber structure for wafer etching, which can eliminate process differences occurring during etching, improve product qualification rate, and avoid extending the processing cycle due to edge ring replacement.

[0007] The technical solution adopted in the present invention is as follows:

[0008] A highly controllable edge ring assembly for wafer etching is disposed around an electrostatic chuck, the highly controllable edge ring assembly comprising:

[0009] a first edge ring, the bottom of which is provided with a first magnetic device, a first inwardly recessed groove portion and / or a first downwardly extending protrusion portion;

[0010] a second edge ring disposed below the first edge ring, with a second magnetic device and a second protrusion extending upwardly and corresponding to the first groove and / or a second groove recessed inwardly and corresponding to the first protrusion disposed on a top portion of the second edge ring; the contact surfaces of the first magnetic device and the second magnetic device have the same polarity, i.e., they repel each other, and the magnetic force of the first magnetic device and / or the second magnetic device is adjustable to enable the first edge ring to move upward;

[0011] The third edge ring is disposed inside the first edge ring and the second edge ring. The inner side of the third edge ring is connected to the electrostatic chuck, and the top of the third edge ring is parallel to the top of the electrostatic chuck.

[0012] Further, the first groove portion, the first protrusion portion, the second groove portion and the second protrusion portion are provided in a circular ring shape and are concentric with the first edge ring and the second edge ring.

[0013] Furthermore, there are two first groove portions and / or two first protrusion portions, and the first magnetic device is arranged between the two; correspondingly, there are two second protrusion portions and / or two second groove portions, and the second magnetic device is arranged between the two.

[0014] Furthermore, the first magnetic device and / or the second magnetic device includes an electromagnet and a built-in power supply.

[0015] Furthermore, the built-in power supply gradually increases the voltage or current provided to the electromagnet so that the first edge ring continues to move upward.

[0016] A processing chamber structure for wafer etching, comprising

[0017] Electrostatic chuck, used to absorb and fix the wafer to be processed;

[0018] A highly controllable edge ring assembly is disposed around the electrostatic chuck, the highly controllable edge ring assembly comprising:

[0019] a first edge ring, the bottom of which is provided with a first magnetic device, a first inwardly recessed groove portion and / or a first downwardly extending protrusion portion;

[0020] a second edge ring disposed below the first edge ring, with a second magnetic device and a second protrusion extending upwardly and corresponding to the first groove and / or a second groove recessed inwardly and corresponding to the first protrusion disposed on a top portion of the second edge ring; the contact surfaces of the first magnetic device and the second magnetic device have the same polarity, i.e., they repel each other, and the magnetic force of the first magnetic device and / or the second magnetic device is adjustable to enable the first edge ring to move upward;

[0021] The third edge ring is disposed inside the first edge ring and the second edge ring. The inner side of the third edge ring is connected to the electrostatic chuck, and the top of the third edge ring is parallel to the top of the electrostatic chuck.

[0022] Further, the first groove portion, the first protrusion portion, the second groove portion and the second protrusion portion are provided in a circular ring shape and are concentric with the first edge ring and the second edge ring.

[0023] Furthermore, there are two first groove portions and / or two first protrusion portions, and the first magnetic device is arranged between the two; correspondingly, there are two second protrusion portions and / or two second groove portions, and the second magnetic device is arranged between the two.

[0024] Furthermore, the first magnetic device and / or the second magnetic device includes an electromagnet and a built-in power supply.

[0025] Furthermore, the built-in power supply gradually increases the voltage or current provided to the electromagnet so that the first edge ring continues to move upward.

[0026] The beneficial effects of the present invention are:

[0027] (1) The present invention proposes a highly controllable edge ring assembly and a processing chamber structure for wafer etching, which can eliminate process differences occurring during etching, improve product qualification rate, and avoid extending the processing cycle due to edge ring replacement. Specifically, a first magnetic device is provided at the bottom of the first edge ring of the highly controllable edge ring assembly, and a second magnetic device is provided at the top of the second edge ring. The contact surfaces of the first magnetic device and the second magnetic device have the same polarity, i.e., they repel each other, and the magnetic force of the first magnetic device and / or the second magnetic device can be adjusted to enable the first edge ring to move upward, thereby avoiding process distribution differences between the edge and center of the wafer due to the etching rate.

[0028] (2) The bottom of the first edge ring in the height-controllable edge ring assembly is provided with a first groove portion and / or a first protrusion portion, and correspondingly, the bottom of the second edge ring is provided with a second protrusion portion corresponding to the first groove portion and / or a second groove portion corresponding to the first protrusion portion. Through the longitudinal cooperation and limiting effect of the groove portion and the protrusion portion, the first edge ring can be prevented from generating lateral movement when moving upward.

[0029] (3) A third edge ring is provided inside the first edge ring and the second edge ring. The inner side of the third edge ring is connected to the electrostatic chuck, and the top of the third edge ring is parallel to the top of the electrostatic chuck. This structure prevents the plasma used in the processing from leaking out. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the existing edge ring.

[0031] Figure 2 It is a structural diagram of a wafer processing chamber.

[0032] Figure 3 It is a schematic structural diagram of the highly controllable edge ring assembly of Example 1 of the present invention.

[0033] Reference numerals: 100 - edge ring, 110 - first edge ring, 110a - first magnetic device, 120 - second edge ring, 120a - second magnetic device, 120b - protrusion, 130 - third edge ring, 200 - electrostatic chuck, 300 - wafer, 400 - ejector pin, 500 - DC voltage input / output. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] This embodiment provides a highly controllable edge ring assembly for wafer etching. The assembly is disposed around an electrostatic chuck 200 and specifically includes a first edge ring 110, a second edge ring 120, and a third edge ring 130. Second edge ring 120 is disposed below first edge ring 110, and third edge ring 130 is disposed inwardly of first and second edge rings 110 and 120. The inner side of third edge ring 130 is connected to electrostatic chuck 200, and its top is parallel to the top of electrostatic chuck 200. This structure prevents leakage of plasma used during processing.

[0037] A first magnetic device 110 a is provided at the bottom of the first edge ring 110 , and a second magnetic device 120 a is provided at the top of the second edge ring 120 . The contact surfaces of the first magnetic device 110 a and the second magnetic device 120 a have the same polarity, i.e., they repel each other. The magnetic force of the first magnetic device 110 a and / or the second magnetic device 120 a can be adjusted to enable the first edge ring 110 to move upward, thereby avoiding process distribution differences between the edge and center of the wafer 300 due to the etching rate.

[0038] Preferably, the first magnetic device 110a and / or the second magnetic device 120a include an electromagnet and a built-in power supply. The built-in power supply gradually increases the voltage or current provided to the electromagnet to cause the first edge ring 110 to continuously move upward. More preferably, the voltage or current of the built-in power supply is set to cause the first edge ring 110 to move upward by 0.1 mm to 1 mm per hour. Specifically, the voltage of the built-in power supply is set within a range of 12 to 110 V, which is related to direct current.

[0039] The bottom of the first edge ring 110 is further provided with a first groove portion recessed inwardly and / or a first protrusion 120b extending downwardly. Correspondingly, the bottom of the second edge ring 120 is further provided with a second protrusion 120b extending upwardly and corresponding to the first groove portion and / or a second groove portion recessed inwardly and corresponding to the first protrusion 120b. Through the longitudinal cooperation and limiting effect of the groove portion and the protrusion 120b, the first edge ring 110 can be prevented from generating lateral movement when moving upward.

[0040] Preferably, the first groove portion, the first protrusion portion 120b, the second groove portion, and the second protrusion portion 120b are arranged in an annular shape and are concentric with the first edge ring 110 and the second edge ring 120. Preferably, there are two first groove portions and / or two first protrusion portions 120b, and the first magnetic device 110a is arranged between the two. Correspondingly, there are two second protrusion portions 120b and / or two second groove portions, and the second magnetic device 120a is arranged between the two.

[0041] Preferably, if Figure 3As shown, two inwardly recessed first grooves are provided at the bottom of the first edge ring 110, and the first magnetic device 110a is provided between the two first grooves; two second protrusions 120b corresponding to the first grooves are provided at the bottom of the second edge ring 120. Through the longitudinal cooperation and limiting effect of the first grooves and the second protrusions 120b, the second magnetic device 120a is provided between the two second protrusions 120b, thereby preventing the first edge ring 110 from moving horizontally when moving upward, and preventing the plasma used in the processing from leaking out.

[0042] Example 2

[0043] This embodiment provides a processing chamber structure for wafer etching, including an electrostatic chuck 200 and a height-controllable edge ring assembly. The electrostatic chuck 200 is used to absorb and fix a wafer 300 to be processed, and the height-controllable edge ring assembly is disposed around the electrostatic chuck 200. Specifically, the height-controllable edge ring assembly includes a first edge ring 110, a second edge ring 120, and a third edge ring 130. The second edge ring 120 is disposed below the first edge ring 110, and the third edge ring 130 is disposed inside the first and second edge rings 110 and 120. The inner side of the third edge ring 130 is connected to the electrostatic chuck 200, and the top is parallel to the top of the electrostatic chuck 200. This structure prevents leakage of plasma used in processing.

[0044] A first magnetic device 110 a is provided at the bottom of the first edge ring 110 , and a second magnetic device 120 a is provided at the top of the second edge ring 120 . The contact surfaces of the first magnetic device 110 a and the second magnetic device 120 a have the same polarity, i.e., they repel each other. The magnetic force of the first magnetic device 110 a and / or the second magnetic device 120 a can be adjusted to enable the first edge ring 110 to move upward, thereby avoiding process distribution differences between the edge and center of the wafer 300 due to the etching rate.

[0045] Preferably, the first magnetic device 110a and / or the second magnetic device 120a include an electromagnet and a built-in power supply. The built-in power supply gradually increases the voltage or current provided to the electromagnet to cause the first edge ring 110 to continuously move upward. More preferably, the voltage or current of the built-in power supply is set to cause the first edge ring 110 to move upward by 0.1 mm to 1 mm per hour.

[0046] The bottom of the first edge ring 110 is further provided with a first groove portion recessed inwardly and / or a first protrusion 120b extending downwardly. Correspondingly, the bottom of the second edge ring 120 is further provided with a second protrusion 120b extending upwardly and corresponding to the first groove portion and / or a second groove portion recessed inwardly and corresponding to the first protrusion 120b. Through the longitudinal cooperation and limiting effect of the groove portion and the protrusion 120b, the first edge ring 110 can be prevented from generating lateral movement when moving upward.

[0047] Preferably, the first groove portion, the first protrusion portion 120b, the second groove portion, and the second protrusion portion 120b are arranged in an annular shape and are concentric with the first edge ring 110 and the second edge ring 120. Preferably, there are two first groove portions and / or two first protrusion portions 120b, and the first magnetic device 110a is arranged between the two. Correspondingly, there are two second protrusion portions 120b and / or two second groove portions, and the second magnetic device 120a is arranged between the two.

[0048] Preferably, if Figure 3 As shown, two inwardly recessed first grooves are provided at the bottom of the first edge ring 110, and the first magnetic device 110a is provided between the two first grooves; two second protrusions 120b corresponding to the first grooves are provided at the bottom of the second edge ring 120. Through the longitudinal cooperation and limiting effect of the first grooves and the second protrusions 120b, the second magnetic device 120a is provided between the two second protrusions 120b, thereby preventing the first edge ring 110 from moving horizontally when moving upward, and preventing the plasma used in the processing from leaking out.

[0049] It should be noted that the terms "center," "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are conventionally placed in the present invention when in use. They are intended solely to facilitate and simplify the description of the present invention, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely for distinction and description, and should not be construed as indicating or implying relative importance.

Claims

1. A highly controllable edge ring assembly for wafer etching, arranged around an electrostatic chuck, characterized in that: The height controllable edge ring assembly comprises: a first edge ring, the bottom of which is provided with a first magnetic device, a first inwardly recessed groove portion and / or a first downwardly extending protrusion portion; a second edge ring disposed below the first edge ring, with a second magnetic device and a second protrusion extending upwardly and corresponding to the first groove and / or a second groove recessed inwardly and corresponding to the first protrusion disposed on a top portion of the second edge ring; the contact surfaces of the first magnetic device and the second magnetic device have the same polarity, i.e., they repel each other, and the magnetic force of the first magnetic device and / or the second magnetic device is adjustable to enable the first edge ring to move upward; The third edge ring is disposed inside the first edge ring and the second edge ring. The inner side of the third edge ring is connected to the electrostatic chuck, and the top of the third edge ring is parallel to the top of the electrostatic chuck.

2. The highly controllable edge ring assembly for wafer etching according to claim 1, wherein: The first groove portion, the first protrusion portion, the second groove portion, and the second protrusion portion are provided in a circular ring shape and are concentric with the first edge ring and the second edge ring.

3. The highly controllable edge ring assembly for wafer etching according to claim 2, wherein: There are two first grooves and / or two first protrusions, and the first magnetic device is arranged between the two; correspondingly, there are two second protrusions and / or two second grooves, and the second magnetic device is arranged between the two.

4. A highly controllable edge ring assembly for wafer etching according to any one of claims 1 to 3, characterized in that: The first magnetic device and / or the second magnetic device includes an electromagnet and a built-in power supply.

5. The highly controllable edge ring assembly for wafer etching according to claim 4, wherein: The built-in power supply provides the electromagnet with a gradually increasing voltage or current so that the first edge ring continues to move upward.

6. A processing chamber structure for wafer etching, characterized in that: include Electrostatic chuck, used to absorb and fix the wafer to be processed; A highly controllable edge ring assembly is disposed around the electrostatic chuck, the highly controllable edge ring assembly comprising: a first edge ring, the bottom of which is provided with a first magnetic device, a first inwardly recessed groove portion and / or a first downwardly extending protrusion portion; a second edge ring disposed below the first edge ring, with a second magnetic device and a second protrusion extending upwardly and corresponding to the first groove and / or a second groove recessed inwardly and corresponding to the first protrusion disposed on a top portion of the second edge ring; the contact surfaces of the first magnetic device and the second magnetic device have the same polarity, i.e., they repel each other, and the magnetic force of the first magnetic device and / or the second magnetic device is adjustable to enable the first edge ring to move upward; The third edge ring is disposed inside the first edge ring and the second edge ring. The inner side of the third edge ring is connected to the electrostatic chuck, and the top of the third edge ring is parallel to the top of the electrostatic chuck.

7. A processing chamber structure for wafer etching according to claim 6, characterized in that: The first groove portion, the first protrusion portion, the second groove portion, and the second protrusion portion are provided in a circular ring shape and are concentric with the first edge ring and the second edge ring.

8. The processing chamber structure for wafer etching according to claim 7, characterized in that: There are two first grooves and / or two first protrusions, and the first magnetic device is arranged between the two; correspondingly, there are two second protrusions and / or two second grooves, and the second magnetic device is arranged between the two.

9. A processing chamber structure for wafer etching according to any one of claims 6 to 8, characterized in that: The first magnetic device and / or the second magnetic device includes an electromagnet and a built-in power supply.

10. The processing chamber structure for wafer etching according to claim 9, characterized in that: The built-in power supply provides the electromagnet with a gradually increasing voltage or current so that the first edge ring continues to move upward.

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