Plasma etching device
By using a suitable bevel structure in the plasma etching device to limit the movement of the focus ring, the problem of eccentricity of the focus ring installation is solved, the uniformity of the etching process and the quality of the wafer are ensured, and the service life of the focus ring is extended .
Patent Information
- Application Number
- CN202420910871.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-28
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-04-28
AI Technical Summary
During semiconductor manufacturing, the focus ring is installed and replaced after being installed and replaced, resulting in eccentricity of the focus ring, resulting in uneven wafer etching and defects.
A plasma etching device is designed to limit the horizontal movement of the focus ring by providing a first inclined surface and a second inclined surface on the contact surface of the focus ring and the support ring, ensuring that it is installed concentrically with the electrostatic suction cup, and avoiding eccentricity problems.
It effectively avoids the eccentricity of the focus ring installation, ensures the uniformity and quality of wafer etching, and extends the service life of the focus ring.
Smart Images
Figure CN222190625U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductor manufacturing, in particular to a plasma etching device. Background Art
[0002] In the manufacturing process of semiconductor devices, plasma etching is a key process for processing wafers into designed patterns. The density distribution of plasma in plasma etching is proportional to the etching rate of the wafer. The higher the density of plasma, the higher the etching rate, and the lower the density of plasma, the lower the etching rate. Due to the combined effect of plasma gas flow and the area of the upper and lower electrodes, the plasma density in the center of the wafer is high and the plasma density in the edge is low, resulting in a higher etching rate in the center of the wafer surface than in the edge, which in turn leads to uneven etching rate of the wafer.
[0003] To solve the above problems, a focusing ring is usually set on the periphery of the wafer, which is equivalent to expanding the radius of the lower electrode outward, so that the edge of the wafer produces the same concentration of plasma as the center, which is conducive to ensuring the uniformity of the etching process in the edge and center areas. The focusing ring is usually made of silicon or silicon carbide. As the etching process time increases, the surface of the focusing ring will also be consumed by plasma etching, and the height of the focusing ring surface will decrease, causing the plasma sheath above the focusing ring to move downward, and the etching collimation of the edge area of the wafer will decrease, so the focusing ring needs to be replaced.
[0004] At present, the focus ring is generally set on the electrostatic chuck through a support ring. In order to facilitate the installation of the focus ring, there is a gap between the focus ring and the electrostatic chuck. When the focus ring is replaced, it is difficult to keep the focus ring and the electrostatic chuck concentric due to the existence of the gap, and the problem of eccentric installation of the focus ring often occurs, which causes the wafer to be placed on the electrostatic chuck from top to bottom, and the inner ring surface of the focus ring is scraped, resulting in defects and scrapping. Utility Model Content
[0005] The utility model aims to provide a plasma etching device, which solves the problem that the existing focusing ring is not concentric with the electrostatic chuck after installation and replacement.
[0006] To achieve the above-mentioned purpose, the utility model provides a plasma etching device, including an electrostatic chuck, a focusing ring and a support ring, wherein the support ring is arranged on the electrostatic chuck, the focusing ring is arranged above the support ring, the lower surface of the focusing ring is provided with a first inclined surface, the upper surface of the support ring is provided with a second inclined surface adapted to the first inclined surface, the first inclined surface and the second inclined surface are fitted with each other to horizontally limit the focusing ring, and the focusing ring is concentrically arranged with the electrostatic chuck.
[0007] Optionally, the first inclined surface is disposed close to the inner ring of the focusing ring, the second inclined surface is disposed close to the inner ring of the supporting ring, and both the first inclined surface and the second inclined surface extend obliquely downward toward a direction close to the center of the electrostatic chuck.
[0008] Optionally, the first inclined surface is disposed close to an outer ring of the focusing ring, the second inclined surface is disposed close to an outer ring of the supporting ring, and both the first inclined surface and the second inclined surface extend obliquely upward in a direction close to a center of the electrostatic chuck.
[0009] Optionally, the lower surface of the focusing ring is provided with two first inclined surfaces to form a trapezoidal depression, and the upper surface of the supporting ring is provided with two second inclined surfaces to form a trapezoidal protrusion, and the trapezoidal depression is matched with the trapezoidal protrusion.
[0010] Optionally, the plasma etching device further includes a plurality of positioning structures, the positioning structures including matching positioning protrusions and positioning recesses, one of the positioning protrusions and the positioning recesses is arranged at the bottom of the focusing ring, and the other is arranged at the top of the support ring.
[0011] Optionally, the positioning protrusion and the positioning recess are in the shape of matching cones.
[0012] Optionally, the inner ring of the focusing ring is provided with a step surface for supporting a wafer.
[0013] Optionally, the support ring is made of aluminum.
[0014] Optionally, the electrostatic chuck is mounted on a base.
[0015] Optionally, an isolation ring is further arranged around the outer circumference of the focusing ring, and the isolation ring is located on the base.
[0016] In a plasma etching device provided by the utility model, by correspondingly arranging the first inclined plane and the second inclined plane that are adapted to each other at the contact surface between the focusing ring and the support ring, the movement of the focusing ring on the horizontal plane can be limited, ensuring that the focusing ring is concentrically arranged with the electrostatic suction cup after installation, thereby avoiding the occurrence of eccentric installation problems of the focusing ring. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Those skilled in the art will appreciate that the drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.
[0018] Figure 1 A schematic diagram of the structure of a plasma etching device provided in Embodiment 1 of the present utility model;
[0019] Figure 2A schematic diagram of the structure of a plasma etching device provided in Embodiment 2 of the present utility model;
[0020] Figure 3 This is a schematic structural diagram of a plasma etching device provided in Embodiment 3 of the present utility model.
[0021] In the attached figure:
[0022] 100 - electrostatic suction cup; 200 - focusing ring; 201 - first inclined surface; 202 - step surface; 300 - support ring; 301 - second inclined surface; 400 - base; 500 - isolation ring. DETAILED DESCRIPTION
[0023] In order to make the purpose, advantages and features of the present utility model clearer, the present utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the present utility model. In order to make the purpose, features and advantages of the present utility model more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Any modification of the structure, change in the proportional relationship or adjustment of the size, in the case of the same or similar effects and purposes that can be achieved by the present utility model, should still fall within the scope of the technical content disclosed by the present utility model.
[0024] As used in the present invention, the singular forms "one", "an", and "the" include plural objects, unless the content clearly indicates otherwise. As used in the present invention, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise. As used in the present invention, the term "several" is generally used in a sense that includes "at least one", unless the content clearly indicates otherwise. As used in the present invention, the term "at least two" is generally used in a sense that includes "two or more", unless the content clearly indicates otherwise. In addition, the terms "first", "second", and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features.
[0025] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0026] Embodiment 1
[0027] Please refer to Figure 1 The embodiment of the utility model provides a plasma etching device, including an electrostatic chuck 100, a focusing ring 200 and a support ring 300, wherein the support ring 300 is arranged on the electrostatic chuck 100, and the focusing ring 200 is arranged above the support ring 300, and the lower surface of the focusing ring 200 is provided with a first inclined surface 201, and the upper surface of the support ring 300 is provided with a second inclined surface 301 adapted to the first inclined surface 201, and the first inclined surface 201 and the second inclined surface 301 are fitted with each other to horizontally limit the focusing ring 200, and the focusing ring 200 is concentrically arranged with the electrostatic chuck 100.
[0028] By setting corresponding matching first bevel 201 and second bevel 301 at the contact surface between the focusing ring 200 and the support ring 300, the movement of the focusing ring 200 on the horizontal plane can be limited without changing the electric potential in the etching chamber (that is, the outer dimensions of each component remain unchanged), ensuring that the focusing ring 200 is concentrically arranged with the electrostatic suction cup 100 in the etching chamber after installation, thereby avoiding the occurrence of eccentric installation problems of the focusing ring 200.
[0029] In this embodiment, the first bevel 201 is disposed close to the inner ring of the focus ring 200 , the second bevel 301 is disposed close to the inner ring of the support ring 300 , and both the first bevel 201 and the second bevel 301 extend obliquely downward toward the center of the electrostatic chuck 100 .
[0030] Furthermore, the plasma etching device further includes a plurality of positioning structures (not shown in the figure), the positioning structures include matching positioning protrusions and positioning recesses, one of the positioning protrusions and the positioning recesses is arranged at the bottom of the focus ring 200, and the other is arranged at the top of the support ring 300. The positioning structure is mainly used to effectively position the installation of the focus ring 200 on the support ring 300 to improve the assembly efficiency. It should be understood that this positioning accuracy is not high and cannot effectively limit the movement of the focus ring 200 on the horizontal plane. Therefore, the combination of the inclined surface can better solve the problem of eccentric installation of the focus ring 200.
[0031] The positioning structure includes the following three design methods, and the present invention does not impose any specific restrictions on them.
[0032] 1) The bottom of the focusing ring 200 is only provided with a plurality of positioning protrusions, and the top of the supporting ring 300 is correspondingly provided with a plurality of positioning recesses, and the positioning protrusions correspond to the positioning recesses one by one;
[0033] 2) The bottom of the focus ring 200 is only provided with a plurality of positioning recesses, and the top of the support ring 300 is correspondingly provided with a plurality of positioning protrusions, and the positioning protrusions correspond to the positioning recesses one by one;
[0034] 3) The bottom of the focusing ring 200 is provided with a plurality of first positioning protrusions and a plurality of first positioning recesses, and the top of the supporting ring 300 is provided with a plurality of second positioning protrusions and a plurality of second positioning recesses, the first positioning protrusions correspond to the second positioning recesses one by one, and the second positioning protrusions correspond to the first positioning recesses one by one.
[0035] Preferably, the positioning protrusion and the positioning recess are in the shape of matching cones, which have a good positioning effect and a certain limiting ability.
[0036] In this embodiment, the inner ring of the focus ring 200 is provided with a step surface 202 for supporting the wafer.
[0037] In this embodiment, the material of the support ring 300 is preferably aluminum.
[0038] In this embodiment, the electrostatic chuck 100 is mounted on a base 400. An electrostatic electrode is disposed inside the electrostatic chuck 100 to generate electrostatic suction force to support and fix the wafer during the process.
[0039] In this embodiment, an isolation ring 500 is further disposed around the outer circumference of the focus ring 200 , and the isolation ring 500 is located on the base 400 .
[0040] Embodiment 2
[0041] Compared with the first embodiment, in the second embodiment, the first inclined surface 201 is arranged close to the outer ring of the focus ring 200, the second inclined surface 301 is arranged close to the outer ring of the support ring 300, and both the first inclined surface 201 and the second inclined surface 301 extend obliquely upward toward the center of the electrostatic chuck 100. Such a design can also achieve the technical effect of limiting the movement of the focus ring 200 on the horizontal plane and ensuring that the focus ring 200 is arranged concentrically with the electrostatic chuck 100 in the etching chamber after installation.
[0042] Embodiment 3
[0043] Compared with the first and second embodiments, in the third embodiment, the lower surface of the focus ring 200 is provided with two first inclined surfaces 201 to form a trapezoidal depression, and the upper surface of the support ring 300 is provided with two second inclined surfaces 301 to form a trapezoidal protrusion, and the trapezoidal depression and the trapezoidal protrusion are adapted. Such a design can also achieve the technical effect of limiting the movement of the focus ring 200 on the horizontal plane and ensuring that the focus ring 200 is concentrically arranged with the electrostatic chuck 100 in the etching chamber after installation.
[0044] In summary, the embodiment of the utility model provides a plasma etching device, which can limit the movement of the focusing ring 200 on the horizontal plane without changing the electric potential in the etching chamber (that is, the outer dimensions of each component remain unchanged) by correspondingly setting a matching first bevel 201 and a second bevel 301 at the contact surface of the focusing ring 200 and the support ring 300, thereby ensuring that the focusing ring 200 is concentrically arranged with the electrostatic suction cup 100 in the etching chamber after installation, thereby avoiding the occurrence of eccentric installation problems of the focusing ring 200.
[0045] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure content belong to the protection scope of the utility model. Obviously, technicians in this field can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations fall within the scope of the utility model and its equivalent technology, the utility model is also intended to include these modifications and variations.
Claims
1. A plasma etching device, It is characterized in that It includes an electrostatic chuck, a focusing ring and a support ring, wherein the support ring is arranged on the electrostatic chuck, the focusing ring is arranged above the support ring, the lower surface of the focusing ring is provided with a first inclined surface, the upper surface of the support ring is provided with a second inclined surface adapted to the first inclined surface, the first inclined surface and the second inclined surface are fitted to each other to horizontally limit the focusing ring, and the focusing ring is concentrically arranged with the electrostatic chuck.
2. The plasma etching device according to claim 1, It is characterized in that The first inclined surface is disposed close to the inner ring of the focus ring, the second inclined surface is disposed close to the inner ring of the support ring, and both the first inclined surface and the second inclined surface extend obliquely downward toward the center of the electrostatic chuck.
3. The plasma etching device according to claim 1, It is characterized in that The first inclined surface is disposed close to the outer ring of the focus ring, the second inclined surface is disposed close to the outer ring of the support ring, and both the first inclined surface and the second inclined surface extend obliquely upward toward a direction close to the center of the electrostatic chuck.
4. The plasma etching device according to claim 1, It is characterized in that The lower surface of the focus ring is provided with two first inclined surfaces to form a trapezoidal depression, and the upper surface of the support ring is provided with two second inclined surfaces to form a trapezoidal protrusion, and the trapezoidal depression is matched with the trapezoidal protrusion.
5. The plasma etching device according to claim 1, It is characterized in that The plasma etching device also includes a plurality of positioning structures, and the positioning structures include matching positioning protrusions and positioning recesses, one of the positioning protrusions and the positioning recesses is arranged at the bottom of the focusing ring, and the other is arranged at the top of the supporting ring.
6. The plasma etching device according to claim 5, It is characterized in that The positioning protrusion and the positioning recess are in the shape of matching cones.
7. The plasma etching device according to claim 1, It is characterized in that The inner ring of the focusing ring is provided with a step surface for supporting a wafer.
8. The plasma etching device according to claim 1, It is characterized in that The support ring is made of aluminum.
9. The plasma etching device according to claim 1, It is characterized in that The electrostatic chuck is mounted on a base.
10. The plasma etching device according to claim 9, It is characterized in that An isolation ring is also arranged around the outer circumference of the focusing ring, and the isolation ring is located on the base.