High-low temperature switchable electrostatic chuck structure
By incorporating a detachable, switchable layer and multifunctional channels into the electrostatic chuck structure, the problem of incompatibility between electrostatic chucks and high and low temperature processes is solved, achieving efficient thermal management and process adaptability, and improving the operational reliability of the equipment and the utilization efficiency of the production line.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAHONG INTEGRATED CIRCUIT (CHENGDU) CO LTD
- Filing Date
- 2026-03-30
- Publication Date
- 2026-06-23
AI Technical Summary
Existing electrostatic chuck structures cannot simultaneously achieve both high-efficiency heat conduction and high-efficiency heat insulation, and cannot flexibly switch between high and low temperature etching processes, resulting in unstable operation of the equipment under different process scenarios.
A high-low temperature switchable electrostatic chuck structure was designed. By setting a detachable and switchable layer between the cooling substrate and the back helium layer, thermally conductive materials or thermal insulation materials can be selectively used according to process requirements. Multiple functional channels are integrated in the cooling channel to achieve efficient heat dissipation or thermal insulation.
It achieves flexible compatibility with high and low temperature processes, improves the process adaptability and thermal management efficiency of electrostatic chucks, reduces equipment modification costs, and improves operational reliability.
Smart Images
Figure CN122270101A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to an electrostatic chuck structure that can switch between high and low temperatures. Background Technology
[0002] Dry etching is one of the most crucial processes in semiconductor manufacturing. Its basic principle is to apply high-frequency, high-voltage light discharge to the etching gas in the reaction chamber under low-pressure conditions, causing the gas to decompose into plasma. The plasma is then used to etch the wafer.
[0003] Temperature is one of the key parameters affecting the etching process, directly determining the chemical reaction rate, reaction equilibrium, and particle mobility. Controlling the temperature inside the reaction chamber directly impacts the etching reaction on the wafer.
[0004] Currently, the industry commonly uses electrostatic chucks (ESCs) to hold wafers and regulate their temperature. A typical ESC has helium gas vents inside to distribute helium gas to the back of the wafer, carrying away the heat generated by the wafer through gas heat conduction and transferring it to the ESC. At the same time, the ESC has cooling channels inside to cool it down.
[0005] However, the existing ESC architecture has the following limitations in practical applications:
[0006] 1. In conventional etching processes, plasma bombardment of wafers generates a large amount of heat, requiring wafer cooling to prevent overheating from affecting the etching effect or damaging the device. Therefore, in such processes, ESCs place greater emphasis on heat dissipation and temperature stability, and ESCs need to have efficient heat conduction and cooling capabilities.
[0007] 2. In high-temperature etching processes, the ESC itself reaches a very high temperature. In this case, the ESC actually needs to have good heat insulation capabilities to prevent the high temperature from being transmitted downwards, causing the sealing rings, cooling pipes, sensors or other precision components below to age and fail due to prolonged heating, which in turn leads to equipment failure or process defects.
[0008] Most ESCs currently in use are integrally machined parts, with fixed designs for their internal heat conduction paths, heating element layouts, and cooling channels. Once this physical structure is formed, its thermodynamic properties are determined, making it impossible to simultaneously meet the two opposing physical requirements of "efficient heat conduction" and "efficient heat insulation" on the same ESC. Consequently, it cannot be simultaneously applied to the two etching scenarios mentioned above. Summary of the Invention
[0009] The purpose of this invention is to provide a high-low temperature switchable electrostatic chuck structure. By setting a detachable and switchable layer, it can achieve flexible compatibility of high and low temperature processes, and significantly improve the process adaptability, thermal management efficiency and operational reliability of the electrostatic chuck.
[0010] To achieve the above objectives, the present invention provides a high-low temperature switchable electrostatic chuck structure, which includes a cooling substrate, a switchable layer and a back helium layer stacked sequentially. The switchable layer is detachably disposed between the cooling substrate and the back helium layer. The back helium layer is provided with multiple helium outlets, and the cooling substrate is provided with a helium inlet.
[0011] The electrostatic chuck structure also includes a cooling channel located in the cooling substrate and the switchable layer.
[0012] Optionally, the electrostatic chuck structure includes a ceramic layer located above the back helium layer, the ceramic layer being used to support the wafer, and the ceramic layer having an outlet hole communicating with the helium outlet.
[0013] Optionally, the electrostatic chuck structure includes a pin hole that sequentially penetrates the cooling substrate, the switchable layer, the back helium layer, and the ceramic layer, and the pin hole is used to allow a pin to move within it.
[0014] Optionally, the electrostatic chuck structure includes a connection hole that passes through the cooling substrate, the switchable layer, and the back helium layer. Fasteners are inserted into the connection hole to fix the cooling substrate, the switchable layer, and the back helium layer together.
[0015] Optionally, the helium back layer is provided with a helium channel, which is connected to the helium outlet; the electrostatic chuck structure includes a fixing post, which is inserted from the helium inlet of the cooling substrate, passes through the cooling substrate and the switchable layer, and is inserted into the helium back layer; the fixing post is provided with a through vent hole, the inlet end of which is located at the helium inlet of the cooling substrate, and the outlet end of which is connected to the helium channel.
[0016] Optionally, the portion of the fixing post located in the helium back layer is provided with external threads for threaded connection with the helium back layer; the end of the fixing post located at the helium inlet of the cooling substrate is provided with a connecting flange, and the fixing post is connected to the cooling substrate through the connecting flange.
[0017] Optionally, a heating element is provided in the back helium layer.
[0018] Optionally, the switchable layer may be selectively made of thermally conductive or thermally insulating materials, depending on process requirements.
[0019] Optionally, the electrostatic chuck structure includes a high-voltage signal detection hole that penetrates the cooling substrate, the switchable layer, and the back helium layer. The high-voltage signal detection hole is used to install a signal connector to detect voltage values.
[0020] Optionally, the back helium layer is provided with a groove, and the switchable layer is provided with a boss that matches the groove. The back helium layer and the switchable layer fit together through the groove and the boss.
[0021] As configured above, the high-low temperature switchable electrostatic chuck structure provided by this invention effectively solves the technical problem that traditional ESCs (electrostatic chucks) cannot simultaneously handle high and low temperature processes through an innovative switchable layer structure. Its core technological advantages are reflected in the following aspects:
[0022] First, it enables flexible switching between process scenarios. This invention features a detachable, switchable layer between the cooling substrate and the back helium layer, selectively using either thermally conductive or thermally insulating materials depending on process requirements. During conventional etching, the switchable layer uses a thermally conductive material, allowing wafer heat to be rapidly transferred to the cooling substrate and carried away by the cooling medium in the cooling channels, ensuring efficient heat dissipation. During high-temperature etching, the switchable layer is replaced with a thermally insulating material, allowing the heating elements embedded in the back helium layer to operate. The thermally insulating material effectively blocks the downward transmission of high temperatures, preventing damage to sensitive components such as the sealing ring below the electrostatic chuck. Thus, the electrostatic chuck structure of this invention is compatible with both etching scenarios, significantly reducing equipment modification costs and improving production line utilization efficiency.
[0023] Secondly, the cooling channels of this invention are distributed simultaneously in the cooling substrate and the switchable layer, forming a continuous heat exchange path; the matching design of the grooves and bosses enhances the interlayer sealing. At the same time, the fixed column penetrates through the cooling substrate and the switchable layer, directly delivering helium to the back helium layer, which not only ensures the smooth flow of helium but also avoids the risk of helium (He) leakage caused by multi-layer assembly.
[0024] Furthermore, multiple functional channels are integrated to ensure device integrity. Pin holes, connection holes, and high-voltage signal detection holes run through each layer of the structure, enabling wafer transfer, interlayer fixing, and RF (radio frequency) system voltage monitoring functions, respectively.
[0025] In summary, this invention achieves flexible compatibility with high and low temperature processes while ensuring a compact structure and complete functionality, significantly improving the process adaptability, thermal management efficiency, and operational reliability of ESC, and has outstanding industrial application value. Attached Figure Description
[0026] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:
[0027] Figure 1 This is a schematic diagram of a high-low temperature switchable electrostatic chuck structure according to an embodiment of the present invention;
[0028] Figure 2 This is a schematic diagram of the fixing column of a high and low temperature switchable electrostatic chuck structure according to an embodiment of the present invention.
[0029] The accompanying figure is labeled as follows:
[0030] 1-Cooling base; 11-Fixing column; 111-Connecting flange; 112-Vent hole; 12-Mounting hole; 13-First cooling channel; 14-Second cooling channel; 2-Switchable layer; 3-Back helium layer; 31-Helium channel; 4-Connecting hole; 5-Ceramic layer; 51-Vent hole; 6-Pin hole; 7-Heating element; 8-High voltage signal detection hole. Detailed Implementation
[0031] In this document, unless otherwise stated, the terms “upper,” “lower,” “left,” “right,” “inner,” “outer,” “front,” “back,” “top,” “bottom,” etc., are used to indicate orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a characteristic orientation and operation, and therefore should not be construed as a limitation of the invention.
[0032] The specific embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.
[0033] Figure 1 This is a schematic diagram of a high and low temperature switchable electrostatic chuck structure according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the fixing column of a high / low temperature switchable electrostatic chuck structure according to an embodiment of the present invention. Please refer to... Figure 1 and Figure 2This invention provides a high / low temperature switchable electrostatic chuck structure for installation in an etching apparatus. The electrostatic chuck structure includes a cooling substrate 1, a switchable layer 2, and a helium backing layer 3 stacked sequentially. The switchable layer 2 is detachably disposed between the cooling substrate 1 and the helium backing layer 3. Further, the electrostatic chuck structure includes multiple connecting holes 4, which penetrate the cooling substrate 1, the switchable layer 2, and the helium backing layer 3. Fasteners are inserted into the connecting holes 4 to securely connect the cooling substrate 1, the switchable layer 2, and the helium backing layer 3. For example, bolts are used to pass through the connecting holes 4 to securely connect the cooling substrate 1, the switchable layer 2, and the helium backing layer 3 to the lower cavity of the etching apparatus. The helium backing layer 3 has multiple helium outlets, and the cooling substrate 1 has a helium inlet.
[0034] The electrostatic chuck structure includes a ceramic layer 5 located above the back helium layer 3. The ceramic layer 5 is used to support the wafer, and it has an outlet hole 51 communicating with the helium outlet on the back helium layer 3. It is understood that helium enters from the helium inlet on the cooling substrate 1 and exits from the outlet hole 51 on the ceramic layer 5. Furthermore, the electrostatic chuck structure includes a pin hole 6, which sequentially penetrates the cooling substrate 1, the switchable layer 2, the back helium layer 3, and the ceramic layer 5, allowing a pin to move within it.
[0035] The helium back layer 3 is provided with a helium channel 31, which is connected to the helium outlet on the helium back layer 3; the electrostatic chuck structure includes a fixing post 11, which is inserted from the helium inlet of the cooling substrate 1, passes through the cooling substrate 1 and the switchable layer 2, and is inserted into the helium back layer 3; the fixing post 11 is provided with a through vent hole 112, the inlet end of the vent hole 112 is located at the helium inlet of the cooling substrate 1, and the outlet end of the vent hole 112 is connected to the helium channel 31.
[0036] For example, the portion of the fixing post 11 located in the back helium layer 3 has external threads for threaded connection with the back helium layer 3; the end of the fixing post 11 located at the helium inlet of the cooling substrate 1 has a connecting flange 111, and the fixing post 11 is connected to the cooling substrate 1 through the connecting flange 111, for example, by installing bolts on the connecting flange 111 to connect with the cooling substrate 1. It is understood that the electrostatic chuck structure has mounting holes 12 for mounting the fixing post 11. The opening of the mounting hole 12 is located at the helium inlet of the cooling substrate 1, the mounting hole 12 penetrates the cooling substrate 1 and the switchable layer 2 and extends into the back helium layer 3, and the portion of the mounting hole 12 located in the back helium layer 3 has internal threads for threaded connection with the fixing post 11.
[0037] The electrostatic chuck structure also includes cooling channels for the flow of cooling medium. These cooling channels are located within the cooling substrate 1 and the switchable layer 2. For example, the cooling channels extend from the cooling substrate 1 into the switchable layer 2 (cooling channels are not shown in the figure and have been omitted). The cooling channels include various independent first cooling channels 13 and second cooling channels 14, with cooling water flowing through the first cooling channels 13 and coolant (chiller liquid) flowing through the second cooling channels 14.
[0038] Preferably, the helium back layer 3 is provided with a heating element 7, such as a heating wire. More preferably, the switchable layer 2 is selectively made of a thermally conductive material or a thermally insulating material according to process requirements. During conventional etching (low temperature), the heating wire is not in operation or provides auxiliary heating. The switchable layer 2 uses a thermally conductive material, and the heat generated by plasma bombardment of the wafer can be effectively carried away by the cooling substrate and the cooling medium in the switchable layer 2 through the thermally conductive material. During high-temperature etching, the heating wire is in operation, and the switchable layer 2 uses a thermally insulating material, which can effectively block the transfer of high-temperature heat from the helium back layer 3. The cooling substrate with embedded cooling channels also provides secondary insulation against high temperatures, preventing high temperatures from affecting other components.
[0039] Furthermore, the electrostatic chuck structure includes a high-voltage signal detection hole 8, which penetrates the cooling substrate 1, the switchable layer 2, and the back helium layer 3. The high-voltage signal detection hole 8 is used to install a signal connector to detect the high voltage value fed back by the RF (radio frequency) system.
[0040] Preferably, the back helium layer 3 is provided with a groove, and the switchable layer 2 is provided with a boss that matches the groove. The back helium layer 3 and the switchable layer 2 fit together through the groove and the boss to improve the sealing effect.
[0041] As configured above, the high-low temperature switchable electrostatic chuck structure provided by this invention effectively solves the technical problem that traditional ESCs (electrostatic chucks) cannot simultaneously handle high and low temperature processes through an innovative switchable layer 2 structure. Its core technological advantages are reflected in the following aspects:
[0042] First, this invention enables flexible switching between process scenarios. A detachable, switchable layer 2 is provided between the cooling substrate 1 and the back helium layer 3, and either a thermally conductive material or a thermally insulating material is selectively used depending on process requirements. During conventional etching, the switchable layer 2 uses a thermally conductive material, allowing wafer heat to be rapidly transferred to the cooling substrate 1 and carried away by the cooling medium in the cooling channels, ensuring efficient heat dissipation. During high-temperature etching, the switchable layer 2 is replaced with a thermally insulating material, and the heating element 7 embedded in the back helium layer 3 operates. The thermally insulating material effectively blocks the downward transmission of high temperatures, preventing damage to sensitive components such as the sealing ring below the electrostatic chuck. Therefore, the electrostatic chuck structure of this invention can accommodate both etching scenarios, significantly reducing equipment modification costs and improving production line utilization efficiency.
[0043] Secondly, the cooling channels of the present invention are simultaneously distributed in the cooling substrate 1 and the switchable layer 2, forming a continuous heat exchange path; the matching design of the groove and the boss enhances the interlayer sealing. At the same time, the fixed column 11 penetrates through the cooling substrate 1 and the switchable layer 2, directly delivering helium to the back helium layer 3, which not only ensures the smooth flow of helium, but also avoids the risk of helium (He) leakage caused by multi-layer assembly.
[0044] In addition, multiple functional channels are integrated to ensure the integrity of the equipment. Pin holes 6, connection holes 4, and high-voltage signal detection holes run through each layer of the structure, enabling wafer transfer, interlayer fixing, and RF (radio frequency) system voltage monitoring functions, respectively.
[0045] In summary, this invention achieves flexible compatibility with high and low temperature processes while ensuring a compact structure and complete functionality, significantly improving the process adaptability, thermal management efficiency, and operational reliability of ESC, and has outstanding industrial application value.
[0046] It should be noted that references to "an embodiment," "an embodiment," "a specific embodiment," "some embodiments," etc., in the specification only indicate that the described embodiment may include a specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in conjunction with an embodiment, whether explicitly described or not, implementing such a feature, structure, or characteristic in conjunction with other embodiments is within the knowledge of those skilled in the art.
[0047] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.
[0048] It should also be noted that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention shall still fall within the scope of protection of the present invention.
[0049] It should also be understood that, unless otherwise specified or indicated, the terms “first,” “second,” “third,” etc., in the specification are used only to distinguish the various components, elements, and steps in the specification, and not to indicate the logical or sequential relationships between the various components, elements, and steps.
[0050] Furthermore, it should be recognized that the terminology described herein is used only to describe particular embodiments and is not intended to limit the scope of the invention. It must be noted that the singular forms “a” and “an” as used herein include plural bases unless the context clearly indicates otherwise. For example, a reference to “a step” or “an apparatus” means a reference to one or more steps or apparatuses, and may include secondary steps and secondary apparatuses. All conjunctions used should be understood in the broadest sense. Also, the word “or” should be understood to have the definition of logical “or” rather than logical “exclusive OR”, unless the context clearly indicates otherwise. Furthermore, implementation of the methods and / or devices in embodiments of the invention may include performing selected tasks manually, automatically, or in combination.
Claims
1. A high-low temperature switchable electrostatic chuck structure, characterized in that, It includes a cooling substrate, a switchable layer and a back helium layer stacked in sequence. The switchable layer is detachably disposed between the cooling substrate and the back helium layer. The back helium layer is provided with multiple helium outlets, and the cooling substrate is provided with a helium inlet. The electrostatic chuck structure also includes a cooling channel located in the cooling substrate and the switchable layer.
2. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The electrostatic chuck structure includes a ceramic layer located above the back helium layer, the ceramic layer being used to support the wafer, and the ceramic layer having an outlet hole communicating with the helium outlet.
3. The high and low temperature switchable electrostatic chuck structure as described in claim 2, characterized in that, The electrostatic chuck structure includes a pin hole that sequentially penetrates the cooling substrate, the switchable layer, the back helium layer, and the ceramic layer, and the pin hole is used to allow a pin to move within it.
4. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The electrostatic chuck structure includes a connection hole that passes through the cooling substrate, the switchable layer, and the back helium layer. Fasteners are inserted into the connection hole to fix the cooling substrate, the switchable layer, and the back helium layer together.
5. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The helium back layer is provided with a helium channel, which is connected to the helium outlet; the electrostatic chuck structure includes a fixing post, which is inserted from the helium inlet of the cooling substrate, passes through the cooling substrate and the switchable layer, and is inserted into the helium back layer; the fixing post is provided with a through vent hole, the inlet end of which is located at the helium inlet of the cooling substrate, and the outlet end of which is connected to the helium channel.
6. The high and low temperature switchable electrostatic chuck structure as described in claim 5, characterized in that, The portion of the fixing post located on the back helium layer has external threads for threaded connection with the back helium layer; the end of the fixing post located at the helium inlet of the cooling substrate has a connecting flange, and the fixing post is connected to the cooling substrate through the connecting flange.
7. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The helium back layer is equipped with heating elements.
8. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The switchable layer may be made of thermally conductive or thermally insulating materials depending on the process requirements.
9. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The electrostatic chuck structure includes a high-voltage signal detection hole that penetrates the cooling substrate, the switchable layer, and the back helium layer. The high-voltage signal detection hole is used to install a signal connector to detect voltage values.
10. The high and low temperature switchable electrostatic chuck structure as described in claim 1, characterized in that, The back helium layer has a groove, and the switchable layer has a boss that matches the groove. The back helium layer and the switchable layer fit together through the groove and the boss.