Electrostatic chuck

Abstract

The utility model discloses a kind of electrostatic chuck, it can be applied to semiconductor technical field, the electrostatic chuck, comprising: ceramic dielectric layer, ceramic insulating layer, base and radio frequency switching system;The one side of the ceramic insulating layer is connected with the ceramic dielectric layer, the other side is connected with the base;The ceramic dielectric layer includes adsorption electrode layer;The ceramic insulating layer includes radio frequency electrode layer and heating electrode layer;The base includes cooling channel and helium channel;The radio frequency switching system is connected with the radio frequency electrode layer and the base respectively.The adsorption electrode layer is in ceramic dielectric layer, radio frequency electrode layer and heating electrode layer are in ceramic insulating layer, improve the surface temperature uniformity of electrostatic chuck and reduce the loss of radio frequency power;By introducing radio frequency switching system, the radio frequency of electrostatic chuck is controlled, meet the demand of different process to different radio frequency condition, improve the process adaptability of electrostatic chuck.

Description

Technical Field

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

[0002] An electrostatic chuck is a device that uses the principle of electrostatic adsorption to fix semiconductor wafers or other flat workpieces. It is an indispensable key component in modern semiconductor manufacturing processes and is mainly used in plasma processes in a vacuum environment, such as etching, chemical vapor deposition, and physical vapor deposition.

[0003] In advanced semiconductor manufacturing processes, as device dimensions shrink, the localized thermal effects generated by high-power plasma etching intensify. Traditional electrostatic chucks face bottlenecks such as insufficient cooling efficiency, thermal stress mismatch, hermeticity degradation, and weakened adsorption force under low-temperature conditions. Especially in the manufacturing processes of memory and logic chips, low-temperature environments can suppress sidewall roughness and improve etching selectivity. However, existing electrostatic chucks struggle to balance high-power input with stable low-temperature fields, and their relatively fixed RF application positions cannot adapt to different process requirements, resulting in low process adaptability of electrostatic chucks.

[0004] Therefore, how to improve the process adaptability of electrostatic chucks is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] To address the aforementioned issues, this invention provides an electrostatic chuck in which the adsorption electrode layer is disposed within a ceramic dielectric layer, and the radio frequency electrode layer and heating electrode layer are disposed within a ceramic insulating layer. This improves the surface temperature uniformity of the electrostatic chuck and reduces radio frequency power loss. Furthermore, by introducing a radio frequency switching system to control the position of the radio frequency application on the electrostatic chuck, the requirements of different processes for different radio frequency conditions are met, thereby improving the process adaptability of the electrostatic chuck.

[0006] In a first aspect, this utility model provides an electrostatic chuck, comprising: a ceramic dielectric layer, a ceramic insulating layer, a substrate, and a radio frequency switching system;

[0007] One side of the ceramic insulating layer is connected to the ceramic dielectric layer, and the other side is connected to the substrate;

[0008] The ceramic dielectric layer includes an adsorption electrode layer;

[0009] The ceramic insulating layer includes a radio frequency electrode layer and a heating electrode layer;

[0010] The substrate includes cooling channels and helium gas channels;

[0011] The radio frequency switching system is connected to both the radio frequency electrode layer and the substrate.

[0012] Optionally, the ceramic dielectric layer is made of alumina ceramic with a mass percentage greater than or equal to 99.7%, and the thickness of the ceramic dielectric layer is less than or equal to 2 mm.

[0013] Optionally, the ceramic insulating layer is made of alumina ceramic with a mass ratio of 96%, and the thickness of the ceramic insulating layer is less than or equal to 3 mm.

[0014] Optionally, the ceramic insulating layer has a puncture-resistant coating on the side surface connected to the substrate.

[0015] Optionally, the heating electrode layer includes n heating zones; where n is a positive integer greater than or equal to 2.

[0016] Optionally, a first low-temperature adhesive layer is provided between the ceramic dielectric layer and the ceramic insulating layer; a second low-temperature adhesive layer is provided between the ceramic insulating layer and the substrate.

[0017] Optionally, a groove is provided between the ceramic dielectric layer and the substrate;

[0018] A protective ring is provided inside the groove;

[0019] The protective ring encloses the first low-temperature adhesive layer, the ceramic insulating layer, and the second low-temperature adhesive layer.

[0020] Optionally, an insulating protective sleeve is provided between the terminals of the adsorption electrode layer, the radio frequency electrode layer, and the heating electrode layer and the substrate.

[0021] Optionally, the radio frequency switching system includes a first radio frequency power supply, a second radio frequency power supply, a first electromagnetic switch, a second electromagnetic switch, and a third electromagnetic switch;

[0022] The first radio frequency power supply is connected to the radio frequency electrode layer via a first electromagnetic switch;

[0023] The second radio frequency power supply is connected to the substrate via a second electromagnetic switch;

[0024] The third electromagnetic switch is disposed between the radio frequency electrode layer and the substrate.

[0025] Optionally, the radio frequency switching system further includes: a host computer;

[0026] The host computer is connected to the first radio frequency power supply, the second radio frequency power supply, the first electromagnetic switch, the second electromagnetic switch, and the third electromagnetic switch, respectively.

[0027] As can be seen from the above technical solutions, compared with the prior art, this utility model has the following advantages:

[0028] This utility model provides an electrostatic chuck comprising a ceramic dielectric layer, a ceramic insulating layer, a substrate, and an RF switching system. One side of the ceramic insulating layer is connected to the ceramic dielectric layer, and the other side is connected to the substrate. The ceramic dielectric layer includes an adsorption electrode layer; the ceramic insulating layer includes an RF electrode layer and a heating electrode layer; the substrate includes a cooling channel and a helium gas channel; and the RF switching system is connected to both the RF electrode layer and the substrate. By placing the adsorption electrode layer within the ceramic dielectric layer and the RF electrode layer and heating electrode layer within the ceramic insulating layer, the surface temperature uniformity of the electrostatic chuck is improved, and RF power loss is reduced. Furthermore, by introducing the RF switching system to control the RF application position of the electrostatic chuck, the requirements of different processes for different RF conditions are met, thus improving the process adaptability of the electrostatic chuck. Attached Figure Description

[0029] Figure 1 A schematic diagram of the structure of an electrostatic chuck provided in an embodiment of this utility model;

[0030] Figure 2 A schematic diagram of a connecting layer provided in an embodiment of this utility model;

[0031] Figure 3 A schematic diagram of the structure of a protective ring provided in an embodiment of this utility model;

[0032] Figure 4 A schematic diagram of the structure of a radio frequency switching system provided in an embodiment of this utility model;

[0033] Figure 5 This is a schematic diagram of the structure of a host computer provided in an embodiment of the present utility model. Detailed Implementation

[0034] As mentioned earlier, existing electrostatic chucks suffer from low process adaptability. Specifically, existing electrostatic chucks are mainly composed of a ceramic dielectric layer (including adsorption electrodes and an RF layer) bonded to a substrate using low-temperature adhesive. Temperature is controlled by circulating low-temperature coolant through cooling channels within the substrate, but this method cannot meet specific process temperature control requirements. Furthermore, the RF position settings of existing electrostatic chucks are relatively fixed, failing to adapt to different process requirements, thus contributing to the low process adaptability of electrostatic chucks.

[0035] To address the aforementioned problems, this invention provides an electrostatic chuck, comprising: a ceramic dielectric layer, a ceramic insulating layer, a substrate, and a radio frequency (RF) switching system. One side of the ceramic insulating layer is connected to the ceramic dielectric layer, and the other side is connected to the substrate; the ceramic dielectric layer includes an adsorption electrode layer; the ceramic insulating layer includes an RF electrode layer and a heating electrode layer; the substrate includes a cooling channel and a helium gas channel; and the RF switching system is connected to both the RF electrode layer and the substrate.

[0036] Thus, by placing the adsorption electrode layer within the ceramic dielectric layer and the RF electrode layer and heating electrode layer within the ceramic insulating layer, the surface temperature uniformity of the electrostatic chuck is improved, and RF power loss is reduced. By introducing an RF switching system to control the RF application position and temperature of the electrostatic chuck, the requirements of different processes for different RF conditions are met, improving the process adaptability of the electrostatic chuck. To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0037] Figure 1 This is a schematic diagram of an electrostatic chuck provided for an embodiment of the present utility model. (In conjunction with...) Figure 1 As shown, an embodiment of the present invention provides an electrostatic chuck, comprising: a ceramic dielectric layer 100, a ceramic insulating layer 200, a substrate 300, and a radio frequency switching system 400;

[0038] One side of the ceramic insulating layer 200 is connected to the ceramic dielectric layer 100, and the other side is connected to the substrate 300;

[0039] The ceramic dielectric layer 100 includes an adsorption electrode layer 110;

[0040] The ceramic insulating layer 200 includes a radio frequency electrode layer 210 and a heating electrode layer 220;

[0041] The substrate 300 includes a cooling channel 310 and a helium channel 320;

[0042] The radio frequency switching system 400 is connected to the radio frequency electrode layer 210 and the substrate 300, respectively.

[0043] The electrostatic chuck provided in this embodiment of the invention is easy to manufacture, low in cost, and has a high yield. Specifically, the electrostatic chuck provided in this embodiment of the invention includes a specific functional structure and control module. The functional structure mainly includes a ceramic dielectric layer 100, a ceramic insulating layer 200, and a substrate 300 arranged sequentially from top to bottom. The ceramic dielectric layer 100 includes an adsorption electrode layer 110, which is formed by firing the adsorption electrode layer 110 together with the ceramic dielectric layer 100. The adsorption electrode layer 110 is used to generate and control an electrostatic field, thereby achieving the adsorption and fixation of the wafer. The ceramic insulating layer 200 includes a radio frequency electrode layer 210 and a heating electrode layer 220, which are formed by firing the radio frequency electrode layer 210 and the heating electrode layer 220 together with the ceramic insulating layer 200. This design reduces the distance between the radio frequency electrode layer and the upper surface of the electrostatic chuck, reducing radio frequency power loss and thus easily meeting the requirements of high-power processing processes. The RF electrode layer 210 is a dedicated electrode for transmitting RF energy. In processes such as dry etching and chemical vapor deposition, plasma is required for the reaction. The RF electrode layer 210 is connected to an external RF power supply. When a high-frequency RF current passes through the RF electrode layer 210, an alternating high-frequency electromagnetic field is generated above the wafer, which ionizes the process gas molecules in the cavity, generating and maintaining a stable and uniform plasma region. The heating electrode layer 220 is used to precisely control the wafer temperature, providing direct and rapid heat to the wafer through electrical heating. The substrate 300 includes a cooling channel 310 and a helium channel 320. The cooling channel 310 typically circulates a temperature-controlled coolant (deionized water or special fluorinated liquid, etc.), continuously removing heat from the chuck and wafer through liquid circulation. The helium channel 320 introduces helium gas at a certain pressure from outside the chuck and delivers it to the back side of the wafer. The RF switching system 400 is connected to the RF electrode layer 210 and the substrate 300 respectively, and is used to control the RF electrode layer 210 and the substrate 300 as RF application positions, so that the electrostatic chuck has the ability to switch RF application positions, thereby meeting the RF conditions required by different processes.

[0044] As one implementation method, regarding the design of the ceramic dielectric layer 100, the ceramic dielectric layer 100 is prepared from alumina ceramic with a mass ratio greater than or equal to 99.7%, and the thickness of the ceramic dielectric layer 100 is less than or equal to 2 mm.

[0045] Specifically, in the electrostatic chuck provided in this embodiment, the ceramic dielectric layer 100 is made of high-purity alumina ceramic with a mass percentage greater than or equal to 99.7%, and its thickness is controlled to be less than 2 mm. This design enables the electrostatic chuck containing the ceramic dielectric layer 100 to meet the requirements of high-power plasma etching.

[0046] As one implementation method, regarding the design of the ceramic insulating layer 200, the ceramic insulating layer 200 is prepared from alumina ceramic with a mass ratio of 96%, and the thickness of the ceramic insulating layer 200 is less than or equal to 3 mm.

[0047] Specifically, in the electrostatic chuck provided in this embodiment, the ceramic insulating layer 200 is made of alumina ceramic with a mass ratio of 96%, and its thickness is controlled within 3 mm, that is, the thickness of the ceramic insulating layer 200 needs to be less than or equal to 3 mm. This design reduces the processing difficulty of the ceramic insulating layer 200, thereby improving the yield of the electrostatic chuck during manufacturing.

[0048] As one implementation, regarding the design of the ceramic insulating layer 200, a breakdown-resistant coating is provided on the side surface of the ceramic insulating layer 200 that is connected to the substrate 300.

[0049] Specifically, in the electrostatic chuck provided in this embodiment of the invention, a breakdown-resistant layer is also provided on the surface of the ceramic insulating layer 200 that is connected to the substrate 300. This design improves the voltage withstand performance and breakdown resistance of the ceramic insulating layer 200.

[0050] As one implementation, regarding the design of the heating electrode layer 220, the heating electrode layer 220 includes n heating zones; where n is a positive integer greater than or equal to 2.

[0051] Specifically, in the electrostatic chuck provided in this embodiment of the invention, the heating electrode layer 220 can be configured with n heating zones, where n is at least 2, meaning the heating electrode layer 220 has at least two heating zones. It is understood that the heating electrode layer 220 can also have more heating zones (e.g., 4 zones, 6 zones, etc.). By designing more heating zones, the temperature regulation requirements within a small area can be met, improving temperature uniformity and thus improving the uniformity of the etching process to better match process requirements.

[0052] As one implementation method, regarding how to connect the various structural components, a first low-temperature adhesive layer is provided between the ceramic dielectric layer 100 and the ceramic insulating layer 200; and a second low-temperature adhesive layer is provided between the ceramic insulating layer 200 and the substrate 300.

[0053] Figure 2 This is a schematic diagram of a connecting layer provided in an embodiment of the present utility model. (In conjunction with...) Figure 2As shown, the various layers are bonded together using a low-temperature adhesive. Specifically, the ceramic dielectric layer 100 and the ceramic insulating layer 200 are bonded together using a first low-temperature adhesive layer 500, while the ceramic insulating layer 200 and the substrate 300 are bonded together using a second low-temperature adhesive layer 600.

[0054] As one implementation method, in order to protect the low-temperature adhesive layer, a groove is provided between the ceramic dielectric layer 100 and the substrate 300;

[0055] A protective ring is provided inside the groove;

[0056] The protective ring encloses the first low-temperature adhesive layer 500, the ceramic insulating layer 200, and the second low-temperature adhesive layer 600.

[0057] Figure 3 This is a schematic diagram of a protective ring provided in an embodiment of the present utility model. (In conjunction with...) Figure 3 As shown, a protective ring 700 is also provided on the outer side of the first low-temperature adhesive layer 500, the ceramic insulating layer 200, and the second low-temperature adhesive layer 600. Specifically, in the electrostatic chuck provided in this embodiment of the present invention, a groove is provided between the lower side of the ceramic dielectric layer 100 and the substrate 300, and this groove is used to house the protective ring 700. It can be understood that the groove contains the protective ring 700 (usually polytetrafluoroethylene, silicone rubber, fluororubber, nitrile rubber, etc.), and the protective ring 700 is used to protect the first low-temperature adhesive layer 500 and the second low-temperature adhesive layer 600, reducing the risk of them being eroded by plasma during the process, thereby improving the overall service life and stability of the electrostatic chuck.

[0058] As one implementation method, regarding the design of the electrostatic chuck, an insulating protective sleeve is provided between the terminals of the adsorption electrode layer 110, the radio frequency electrode layer 210, and the heating electrode layer 220 and the substrate 300.

[0059] In this embodiment of the invention, an insulating protective sleeve can be provided between the terminals of the adsorption electrode layer 110, the radio frequency electrode layer 210, and the heating electrode layer 220 and the substrate 300. Specifically, female terminals can be first led out at the terminals of the adsorption electrode layer 110, the radio frequency electrode layer 210, and the heating electrode layer 220 by welding, and then an insulating protective sleeve is provided between the female terminals and the substrate 300 to fill the gap, thus ensuring complete insulation between the two during operation. Commonly used materials for the insulating protective sleeve include ceramics, polyetherimide, polyetheretherketone, and polyetherketoneketone.

[0060] Figure 4 This is a schematic diagram of a radio frequency switching system provided in an embodiment of the present utility model. (In conjunction with...) Figure 4As shown, regarding the design of the radio frequency switching system 400, the radio frequency switching system 400 includes a first radio frequency power supply 410, a second radio frequency power supply 420, a first electromagnetic switch 430, a second electromagnetic switch 440, and a third electromagnetic switch 450.

[0061] The first radio frequency power supply 410 is connected to the radio frequency electrode layer 210 through the first electromagnetic switch 430;

[0062] The second radio frequency power supply 420 is connected to the substrate 300 via the second electromagnetic switch 440;

[0063] The third electromagnetic switch 450 is disposed between the radio frequency electrode layer 210 and the substrate 300.

[0064] Specifically, the RF electrode layer 210 and the substrate 300 are respectively connected to a first RF power supply 410 and a second RF power supply 420. A first electromagnetic switch 430 is disposed between the RF electrode layer 210 and the first RF power supply 410, and a second electromagnetic switch 440 is disposed between the substrate 300 and the second RF power supply 420. Additionally, a third electromagnetic switch 450 is disposed between the RF electrode layer 210 and the substrate 300. Thus, by opening and closing the electromagnetic switches, the RF position is switched, thereby meeting different process requirements.

[0065] Figure 5 This is a schematic diagram of a host computer provided for an embodiment of the present utility model. (In conjunction with...) Figure 5 As shown, regarding how to design the radio frequency switching system 400, the radio frequency switching system 400 also includes: a host computer 460;

[0066] The host computer 460 is connected to the first radio frequency power supply 410, the second radio frequency power supply 420, the first electromagnetic switch 430, the second electromagnetic switch 440, and the third electromagnetic switch 450, respectively.

[0067] In the electrostatic chuck 800 provided in this embodiment of the utility model, the radio frequency switching system 400 is further provided with a host computer 460. Specifically, its operation can be as follows: when the host computer 460 controls the first electromagnetic switch 430 to close and controls the second electromagnetic switch 440 and the third electromagnetic switch 450 to open, the first radio frequency power supply 410 supplies power to the radio frequency electrode layer 210. At this time, the distance between the radio frequency application position and the wafer is reduced, reducing radio frequency power loss and meeting the requirements of high-power processing technology; when the host computer 460 controls the second electromagnetic switch 440 to close and controls the first electromagnetic switch 430 and the third electromagnetic switch 450 to open, the second radio frequency power supply 420 supplies power to the substrate 3... With power supplied at 00, the distance between the RF application point and the wafer is relatively large, meeting the requirements of ordinary processing. When the host computer 460 controls the first electromagnetic switch 430 and the third electromagnetic switch 450 to close, and controls the second electromagnetic switch 440 to open, the first RF power supply 410 simultaneously supplies power to the RF electrode layer 210 and the substrate 300. Compared to the first operating mode (first electromagnetic switch 430 closed, second electromagnetic switch 440 and third electromagnetic switch 450 open), the RF application area is larger, enhancing the processing effect on the wafer edge. This allows for semiconductor processing under different conditions to be achieved within a single reaction chamber.

[0068] In summary, the electrostatic chuck provided by this utility model includes a ceramic dielectric layer, a ceramic insulating layer, a substrate, and an RF switching system. One side of the ceramic insulating layer is connected to the ceramic dielectric layer, and the other side is connected to the substrate. The ceramic dielectric layer includes an adsorption electrode layer; the ceramic insulating layer includes an RF electrode layer and a heating electrode layer; the substrate includes a cooling channel and a helium gas channel; and the RF switching system is connected to both the RF electrode layer and the substrate. By placing the adsorption electrode layer within the ceramic dielectric layer and the RF electrode layer and heating electrode layer within the ceramic insulating layer, the surface temperature uniformity of the electrostatic chuck is improved, and RF power loss is reduced. Furthermore, by introducing the RF switching system to control the RF application position and temperature of the electrostatic chuck, the requirements of different processes for different RF conditions are met, thus improving the process adaptability of the electrostatic chuck.

[0069] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electrostatic chuck, characterized in that, The electrostatic chuck includes: a ceramic dielectric layer, a ceramic insulating layer, a substrate, and a radio frequency switching system; One side of the ceramic insulating layer is connected to the ceramic dielectric layer, and the other side is connected to the substrate; The ceramic dielectric layer includes an adsorption electrode layer; The ceramic insulating layer includes a radio frequency electrode layer and a heating electrode layer; The substrate includes cooling channels and helium gas channels; The radio frequency switching system is connected to both the radio frequency electrode layer and the substrate.

2. The electrostatic chuck according to claim 1, characterized in that, The radio frequency switching system includes a first radio frequency power supply, a second radio frequency power supply, a first electromagnetic switch, a second electromagnetic switch, and a third electromagnetic switch. The first radio frequency power supply is connected to the radio frequency electrode layer via a first electromagnetic switch; The second radio frequency power supply is connected to the substrate via a second electromagnetic switch; The third electromagnetic switch is disposed between the radio frequency electrode layer and the substrate.

3. The electrostatic chuck according to claim 2, characterized in that, The radio frequency switching system further includes: a host computer; The host computer is connected to the first radio frequency power supply, the second radio frequency power supply, the first electromagnetic switch, the second electromagnetic switch, and the third electromagnetic switch, respectively.

4. The electrostatic chuck according to claim 1, characterized in that, The ceramic dielectric layer is made of alumina ceramic with a mass percentage greater than or equal to 99.7%, and the thickness of the ceramic dielectric layer is less than or equal to 2 mm.

5. The electrostatic chuck according to claim 1, characterized in that, The ceramic insulating layer is made of alumina ceramic with a mass ratio of 96%, and the thickness of the ceramic insulating layer is less than or equal to 3 mm.

6. The electrostatic chuck according to claim 1, characterized in that, The ceramic insulating layer has a breakdown-resistant coating on the side surface that is connected to the substrate.

7. The electrostatic chuck according to claim 1, characterized in that, The heating electrode layer includes n heating zones; where n is a positive integer greater than or equal to 2.

8. The electrostatic chuck according to claim 1, characterized in that, A first low-temperature adhesive layer is provided between the ceramic dielectric layer and the ceramic insulating layer; a second low-temperature adhesive layer is provided between the ceramic insulating layer and the substrate.

9. The electrostatic chuck according to claim 8, characterized in that, A groove is provided between the ceramic dielectric layer and the substrate; A protective ring is provided inside the groove; The protective ring encloses the first low-temperature adhesive layer, the ceramic insulating layer, and the second low-temperature adhesive layer.

10. The electrostatic chuck according to claim 1, characterized in that, An insulating protective sleeve is provided between the terminals of the adsorption electrode layer, the radio frequency electrode layer, and the heating electrode layer and the substrate.

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