Electrostatic chuck

Abstract

The utility model relates to the technical field of semiconductor manufacturing, in particular to an electrostatic chuck which comprises a base and a first dielectric layer, an adsorption electrode layer, a second dielectric layer, a radio frequency electrode layer and a third dielectric layer which are sequentially arranged from top to bottom, and the lower surface of the third dielectric layer is arranged on the upper surface of the base; the radio frequency electrode layer is a circular radio frequency electrode layer. Compared with the prior art that a metal base is used as a radio frequency electrode, the radio frequency electrode layer is located between the second dielectric layer and the third dielectric layer, the shielding effect of the silica gel layer on radio frequency is avoided, and the working effect of the radio frequency electrode is guaranteed. Meanwhile, compared with an existing annular radio frequency electrode, the radio frequency electrode layer is of a circular structure, the coverage of the layout area is wide, the influence effect on plasma distribution is more remarkable, the uniformity of plasma distribution is better improved, and the consistency of the technological process is improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, specifically to an electrostatic chuck. Background Technology

[0002] In semiconductor manufacturing processes, electrostatic chucks are used to hold semiconductor wafers in a vacuum environment. The electrostatic chuck places a plate-shaped sample, such as a semiconductor wafer, on its mounting surface, and generates electrostatic forces between the plate-shaped sample and the electrode layer, thereby adsorbing and fixing the plate-shaped sample. In recent years, with the increasing functionality of electrostatic chucks, components are being developed that embed various electrode layers, other than those used for electrostatic adsorption, within the electrostatic chuck components. Conductors such as radio frequency (RF) electrodes, clamping electrodes, and / or resistance heating elements are formed within a ceramic material matrix or on the surface of a substrate in the base, serving as heaters and / or electrostatic chucks.

[0003] In existing technologies, some electrostatic chucks use metal bases as radio frequency (RF) electrodes. Because the metal base and ceramic functional layer are connected via silicone, the reliability differs significantly from those with built-in RF electrodes and high-temperature co-firing. Furthermore, the silicone layer provides some shielding for RF, affecting the performance of the RF electrodes. Additionally, many electrostatic chucks use ring-shaped RF electrodes, making it difficult to control plasma density and hindering plasma distribution uniformity. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, the purpose of this invention is to provide an electrostatic chuck that achieves its adsorption function through an adsorption electrode layer. Simultaneously, the addition of a radio frequency electrode layer allows radio frequency power to be transmitted to the electrostatic chuck, generating an electrostatic field that results in a more uniform plasma distribution, thereby better adsorption and temperature control of the wafer to be processed. This electrostatic chuck has a simple manufacturing process, reliable lifespan, strong practicality, and wide applicability.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An electrostatic chuck includes a base and a first dielectric layer, an adsorption electrode layer, a second dielectric layer, a radio frequency electrode layer, and a third dielectric layer arranged sequentially from top to bottom, wherein the lower surface of the third dielectric layer is disposed on the upper surface of the base; the radio frequency electrode layer is a circular radio frequency electrode layer.

[0007] Furthermore, the adsorption electrode layer includes at least one adsorption electrode.

[0008] Furthermore, the adsorption electrode layer includes a first adsorption electrode and a second adsorption electrode, the first adsorption electrode surrounds the outer periphery of the second adsorption electrode, and the first adsorption electrode and the second adsorption electrode are respectively provided with a first adsorption electrode lead-out end and a second adsorption electrode lead-out end.

[0009] Furthermore, the first dielectric layer, the second dielectric layer, and the third dielectric layer are all ceramic dielectric layers.

[0010] Furthermore, the radio frequency electrode layer is made of metal wires woven into a mesh.

[0011] Furthermore, the radio frequency electrode layer is made of at least one of molybdenum, tungsten, and molybdenum-tungsten alloy.

[0012] Furthermore, the cross-section of the ceramic dielectric layer is either circular or polygonal.

[0013] Furthermore, the cross-section of the base is either circular or polygonal.

[0014] The beneficial effects of this invention are as follows: The electrostatic chuck of this invention integrates radio frequency bias and adsorption functions. It has a simple structure and is easy to use. Compared to existing technologies that use a metal base as the radio frequency electrode, the radio frequency electrode layer is located between the second and third dielectric layers, avoiding the shielding effect of the silicone layer on the radio frequency and ensuring the working effect of the radio frequency electrode. Furthermore, compared to existing ring-shaped radio frequency electrodes, the radio frequency electrode layer adopts a circular structure, providing a wider coverage area and a more significant impact on plasma distribution, thus increasing plasma distribution uniformity and improving process consistency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the three-dimensional structure of an electrostatic chuck.

[0016] Figure 2 This is a top view of the electrostatic chuck.

[0017] Figure 3 This is a partial cross-sectional view of the electrostatic chuck.

[0018] Figure 4 This is a schematic diagram of the adsorption electrode layer.

[0019] Figure 5 This is a schematic diagram of the radio frequency electrode layer.

[0020] The reference numerals in the figures include:

[0021] 1. Base; 2. First dielectric layer; 3. Adsorption electrode layer; 31. First adsorption electrode; 32. Second adsorption electrode; 4. Second dielectric layer; 5. Radio frequency electrode layer; 6. Third dielectric layer. Detailed Implementation

[0022] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0023] like Figure 1-5 As shown, an electrostatic chuck is characterized by comprising a base 1 and, from top to bottom, a first dielectric layer 2, an adsorption electrode layer 3, a second dielectric layer 4, a radio frequency electrode layer 5, and a third dielectric layer 6, wherein the lower surface of the third dielectric layer 6 is disposed on the upper surface of the base 1; and the radio frequency electrode layer 5 is a circular radio frequency electrode layer.

[0024] This invention provides an electrostatic chuck integrating radio frequency (RF) bias and adsorption functions. The electrostatic chuck has a simple structure and is easy to use. The adsorption electrode layer 3 generates an electrostatic adsorption force on the mounting surface of the first dielectric layer 2 by applying voltage to hold the wafer. The RF electrode layer 5 generates plasma on the plate-shaped sample by applying voltage. That is, the RF electrode layer 5 can transmit RF power to the electrostatic chuck, generating an electrostatic field that makes the plasma distribution more uniform, thereby better adsorbing and controlling the temperature of the wafer to be processed. Furthermore, compared to the prior art using a metal base 1 as the RF electrode, the RF electrode layer 5 is located between the second dielectric layer 4 and the third dielectric layer 6, avoiding the shielding effect of the silicone layer on the RF, thus ensuring the working effect of the RF electrode. Moreover, the RF electrode layer 5 is a circular RF electrode layer. Compared to the existing ring-shaped RF electrodes, the circular structure has a wider coverage area, a more significant effect on plasma distribution, and is more conducive to increasing plasma distribution uniformity and improving process consistency.

[0025] Furthermore, the adsorption electrode layer 3 includes at least one adsorption electrode. The adsorption electrode layer 3 may be provided with a single adsorption electrode or multiple adsorption electrodes.

[0026] In this embodiment, the adsorption electrode layer 3 adopts a dual-electrode configuration. Specifically, the adsorption electrode layer 3 includes two adsorption electrodes, namely a first adsorption electrode 31 and a second adsorption electrode 32. The first adsorption electrode 31 surrounds the outer periphery of the second adsorption electrode 32, and the space between the first adsorption electrode 31 and the second adsorption electrode 32 is a blank area of ​​the adsorption electrode layer 3. The first adsorption electrode 31 and the second adsorption electrode 32 are respectively provided with a first adsorption electrode lead-out end and a second adsorption electrode lead-out end, which can effectively improve the adsorption effect.

[0027] Furthermore, the first dielectric layer 2, the second dielectric layer 4, and the third dielectric layer 6 are all ceramic dielectric layers, which improves the stability and durability of the electrostatic chuck.

[0028] Furthermore, the radio frequency electrode layer 5 is made of metal wire woven into a mesh. Specifically, the radio frequency electrode layer 5 is prepared into a mesh using a metal wire weaving process, and then laser-cut to the appropriate size and shape. The manufacturing process of the radio frequency electrode layer 5 is simple and conducive to large-scale industrial production.

[0029] Furthermore, the radio frequency electrode layer 5 is made of at least one of molybdenum, tungsten, and molybdenum-tungsten alloy. In this embodiment, the metal wire is at least one of molybdenum, tungsten, and molybdenum-tungsten alloy, which facilitates the transmission of radio frequency power from the radio frequency electrode layer 5 to the electrostatic chuck.

[0030] Furthermore, the cross-section of the ceramic dielectric layer is either circular or polygonal. The cross-sectional shape of the ceramic dielectric layer can be set as needed, making it widely applicable.

[0031] Furthermore, the cross-section of the base is either circular or polygonal. The cross-sectional shape of the base can be set as needed, making it widely applicable.

[0032] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. An electrostatic chuck, characterized in that: It includes a base (1) and a first dielectric layer (2), an adsorption electrode layer (3), a second dielectric layer (4), a radio frequency electrode layer (5) and a third dielectric layer (6) arranged sequentially from top to bottom. The lower surface of the third dielectric layer (6) is disposed on the upper surface of the base (1). The radio frequency electrode layer (5) is a circular radio frequency electrode layer.

2. The electrostatic chuck according to claim 1, characterized in that: The adsorption electrode layer (3) includes at least one adsorption electrode.

3. The electrostatic chuck according to claim 1, characterized in that: The adsorption electrode layer (3) includes a first adsorption electrode (31) and a second adsorption electrode (32). The first adsorption electrode (31) surrounds the outer periphery of the second adsorption electrode (32). The first adsorption electrode (31) and the second adsorption electrode (32) are respectively provided with a first adsorption electrode lead-out end and a second adsorption electrode lead-out end.

4. The electrostatic chuck according to claim 1, characterized in that: The first dielectric layer (2), the second dielectric layer (4) and the third dielectric layer (6) are all ceramic dielectric layers.

5. The electrostatic chuck according to claim 1, characterized in that: The radio frequency electrode layer (5) is made of metal wires woven into a mesh.

6. The electrostatic chuck according to claim 1, characterized in that: The radio frequency electrode layer (5) is made of at least one of molybdenum, tungsten, and molybdenum-tungsten alloy.

7. The electrostatic chuck according to claim 4, characterized in that: The cross-section of the ceramic dielectric layer is either circular or polygonal.

8. The electrostatic chuck according to claim 1, characterized in that: The cross-section of the base is either circular or polygonal.

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