Electrostatic chuck, semiconductor processing equipment and manufacturing method
By using a mixture of high dielectric constant material and insulating material in the dielectric layer of the electrostatic chuck, and employing whisker-like and 3D printing technologies, the problem of insufficient dielectric constant in the dielectric layer was solved, resulting in better RF energy distribution and wafer etching effects, and improving the density and reliability of the dielectric layer.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-09
- Publication Date
- 2026-04-14
AI Technical Summary
The dielectric constant of the dielectric layer of the existing electrostatic chuck is relatively small, which leads to uneven distribution of radio frequency energy and affects the wafer etching effect, especially in deep hole and high aspect ratio trench etching processes.
A dielectric layer is prepared by mixing a high dielectric constant material with an insulating material. The high dielectric constant material is in the form of whiskers and has a mass percentage of 0.5% to 1% in the dielectric layer. The layers are then laid out alternately using a 3D printing process to form a uniform distribution.
This improves the dielectric constant and capacitance of the dielectric layer, reduces the distribution of RF energy in the electrostatic chuck, increases the RF energy of the sheath, ensures the wafer processing effect, and enhances the density and reliability of the dielectric layer.
Smart Images
Figure CN121865890A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor fabrication technology, and in particular to an electrostatic chuck, semiconductor processing equipment, and manufacturing method. Background Technology
[0002] In semiconductor fabrication, electrostatic chucks (ESCs) are typically used to hold and hold wafers to ensure their positional stability during the process. An ESC consists of an electrode layer and a dielectric layer surrounding the electrode layer; the dielectric layer is commonly made of aluminum oxide.
[0003] Faced with increasingly stringent etching process requirements, such as etching deeper and straighter holes and trenches with high aspect ratios, it is necessary to increase the radio frequency (RF) energy of the sheath layer. However, in existing technologies, the dielectric layer is made of alumina, with a dielectric constant of approximately 10 or less. This results in a small capacitance between the wafer and the electrostatic chuck, causing more RF energy to be allocated to the electrostatic chuck, and consequently, less RF energy to be allocated to the sheath layer, affecting wafer etching. Therefore, it is necessary to adjust the material used in the fabrication of the electrostatic chuck. Summary of the Invention
[0004] The purpose of this invention is to provide an electrostatic chuck, a semiconductor processing device, and a manufacturing method that can increase the dielectric constant of the dielectric layer of the electrostatic chuck, thereby increasing the capacitance formed between the wafer and the electrostatic chuck. This results in a reduction of the radio frequency energy allocated to the electrostatic chuck and an increase of the radio frequency energy allocated to the sheath layer, ensuring that the wafer's processing results meet the requirements.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0006] An electrostatic chuck, comprising:
[0007] Electrode layer;
[0008] A dielectric layer is disposed above the electrode layer; the dielectric layer is prepared from a mixture comprising a high dielectric constant material and an insulating material;
[0009] The high dielectric constant material is in the form of whiskers, and the dielectric constant of the high dielectric constant material is greater than that of the insulating material; the mass percentage of the high dielectric constant material in the mixture is 0.5% to 1%.
[0010] Optionally, the high dielectric constant material and the insulating material are uniformly distributed in the dielectric layer.
[0011] Optionally, the high dielectric constant material and the insulating material are alternately laid in layers in the dielectric layer, and the (2n-1)th layer is the insulating material and the 2nth layer is the high dielectric constant material; n = 1, 2, 3...N, where N is a positive integer.
[0012] Optionally, the insulating material is in granular form.
[0013] Optionally, the insulating material is in the form of whiskers.
[0014] Optionally, the whisker has a diameter greater than 8 nm and a length greater than 200 nm.
[0015] Optionally, the high dielectric constant material is a carbide, which includes silicon carbide and boron carbide.
[0016] Optionally, the high dielectric constant material is a nitride, which includes silicon nitride and boron nitride.
[0017] Optionally, the insulating material is aluminum oxide, yttrium oxide, or aluminum nitride.
[0018] On the other hand, the present invention also provides a semiconductor processing apparatus, comprising: a reaction chamber; and an electrostatic chuck as described above, the electrostatic chuck being disposed within the reaction chamber.
[0019] In another aspect, the present invention also provides a method for manufacturing the electrostatic chuck as described above, comprising:
[0020] Form an electrode layer;
[0021] The dielectric layer is prepared using a mixture of high dielectric constant materials and insulating materials;
[0022] The dielectric layer is disposed on the electrode layer and the electrode layer and the dielectric layer are sintered together to form the electrostatic chuck.
[0023] Optionally, the step of preparing the dielectric layer includes:
[0024] The high dielectric constant material is mixed evenly with the insulating material;
[0025] The high dielectric constant material, which is mixed uniformly, is sintered together with the insulating material to form the dielectric layer.
[0026] Optionally, the step of preparing the dielectric layer includes:
[0027] The (2n-1)th layer is prepared using 3D printing technology and the aforementioned insulating material; n = 1, 2, 3…N, where N is a positive integer;
[0028] The 2n-th layer is prepared using 3D printing technology and the high dielectric constant material, and the 2n-th layer is laid on the 2n-1-th layer;
[0029] The 2n-1 layer and the 2n layer, laid in sequence, are sintered together to form the dielectric layer.
[0030] This invention has at least one of the following advantages:
[0031] This invention provides an electrostatic chuck, a semiconductor processing apparatus, and a manufacturing method. The electrostatic chuck includes an electrode layer and a dielectric layer disposed above the electrode layer. The dielectric layer is prepared using a mixture of a high-dielectric-constant material and an insulating material, wherein the dielectric constant of the high-dielectric-constant material is greater than that of the insulating material. Compared to dielectric layers prepared using a single insulating material in the prior art, the dielectric layer prepared in this invention has a larger dielectric constant, resulting in increased capacitance and decreased impedance between the wafer and the electrostatic chuck. This leads to reduced radio frequency (RF) energy allocated to the electrostatic chuck and increased RF energy allocated to the sheath layer, thereby ensuring that the wafer processing results meet requirements.
[0032] In this invention, the high dielectric constant material is in the form of whiskers, which can more effectively improve the dielectric constant of the dielectric layer. When the dielectric constant of the dielectric layer is increased to a certain value, compared with common granular materials, the amount of whisker-shaped high dielectric constant material used in this invention can be less, thereby controlling the mass percentage of high dielectric constant material in the mixture to 0.5% to 1%. This achieves the goal of improving the dielectric constant of the dielectric layer while ensuring the compactness and reliability of the dielectric layer.
[0033] In this invention, the whiskers have a diameter greater than 8 nm and a length greater than 200 nm to ensure that the whisker-shaped high dielectric constant material can better improve the dielectric constant of the dielectric layer.
[0034] This invention can use 3D printing technology to prepare dielectric layers, which can orderly and controllably dop high dielectric constant materials into insulating materials, avoiding the uncontrollable diffusion of high dielectric constant materials that occurs in conventional processing methods. This ensures the uniform distribution of high dielectric constant materials in the dielectric layer, and thus helps to improve the dielectric constant of the dielectric layer. Attached Figure Description
[0035] Figure 1 This is a longitudinal cross-sectional schematic diagram of an electrostatic chuck provided by the present invention;
[0036] Figure 2 This is a schematic cross-sectional view of the dielectric layer of an electrostatic chuck provided in Embodiment 1 of the present invention, showing a uniform distribution of insulating material and high dielectric material.
[0037] Figure 3 This is a longitudinal cross-sectional view of an electrostatic chuck provided in Embodiment 1 of the present invention, showing that insulating material and high dielectric constant material are alternately laid in the dielectric layer.
[0038] Figure 4 This is a schematic diagram of the structure of a semiconductor processing device provided by the present invention;
[0039] Figure 5 This is a flowchart of a method for manufacturing an electrostatic chuck provided by the present invention. Detailed Implementation
[0040] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the electrostatic chuck, semiconductor processing equipment, and manufacturing method proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.
[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0042] Combined with appendix Figures 1-3As shown, this embodiment provides an electrostatic chuck 100 for carrying and adsorbing a wafer 200. The electrostatic chuck 100 includes an electrode layer 110 and a dielectric layer 120 disposed above the electrode layer 110. The electrode layer 110 can be connected to a DC power supply (not shown in the figure) to generate an electrostatic attraction between the electrode layer 110 and the wafer 200, thereby adsorbing the wafer 200 onto the electrostatic chuck 100 and preventing the wafer 200 from moving during the process.
[0043] Specifically, during the processing of the wafer 200, the electrostatic chuck 100 can be connected as a lower electrode to an RF power supply (not shown in the figure) to form an RF electric field between the lower electrode and the upper electrode opposite to it. This ionizes the process gas located between the lower and upper electrodes into plasma, thereby processing the wafer 200. In this case, the dielectric constant of the dielectric layer 120 will affect the capacitance formed between the wafer 200 and the electrostatic chuck 100, thus affecting the distribution of RF energy in the sheath and the electrostatic chuck 100, and consequently affecting the processing result of the wafer 200. More specifically, the larger the dielectric constant of the dielectric layer 120, the larger the capacitance formed between the wafer 200 and the electrostatic chuck 100, the less RF energy is distributed to the electrostatic chuck 100 and the more RF energy is distributed to the sheath, which is beneficial to the processing of the wafer 200; conversely, it is detrimental to the processing of the wafer 200.
[0044] Please continue to refer to this. Figure 2 and Figure 3 The dielectric layer 120 is prepared from a mixture comprising a high dielectric constant material B and an insulating material A; the high dielectric constant material B is whisker-shaped, and the dielectric constant of the high dielectric constant material B is greater than that of the insulating material A; the mass percentage of the high dielectric constant material B in the mixture is 0.5% to 1%.
[0045] Specifically, compared to the prior art which uses a single insulating material A to prepare the dielectric layer, this embodiment uses a mixture including the high dielectric constant material B and the insulating material A to prepare the dielectric layer 120. The high dielectric constant material B has a higher dielectric constant than the insulating material A, which increases the dielectric constant of the dielectric layer 120. This increases the dielectric constant of the dielectric layer 120 prepared in this embodiment, thereby increasing the capacitance between the wafer 200 and the electrostatic chuck 100 and decreasing the impedance between them. Consequently, the radio frequency energy allocated to the electrostatic chuck 100 decreases, and the radio frequency energy allocated to the sheath increases, ensuring that the processing results of the wafer 200 meet the requirements. Furthermore, the larger the dielectric constant of the dielectric layer 120, the greater the corresponding breakdown strength. In processes with high radio frequency power applied to the electrostatic chuck 100 (such as high aspect ratio etching processes), the electrostatic chuck 100 can be effectively prevented from being broken down, thereby ensuring the reliability of the electrostatic chuck 100.
[0046] Furthermore, using the mixture comprising the high dielectric constant material B and the insulating material A to prepare the dielectric layer 120 can also improve the mechanical properties of the dielectric layer 120, such as bending strength, elastic modulus, Vickers hardness and fracture toughness, thereby extending the service life of the electrostatic chuck 100.
[0047] Specifically, the high dielectric constant material B is whisker-shaped, resulting in a more continuous distribution of the high dielectric constant material B in the dielectric layer 120, thereby exhibiting better conductivity and effectively improving the dielectric constant of the dielectric layer 120. More specifically, when the dielectric layer 120 is prepared using conventional processing methods (such as hot pressing, hot isostatic pressing, sintering, etc.), the whisker-shaped high dielectric constant material B easily forms a network structure, which can further improve the dielectric constant of the dielectric layer 120. As can be seen from the above, compared with common granular materials, the whisker-shaped high dielectric constant material B in this embodiment can more effectively improve the dielectric constant of the dielectric layer 120; therefore, when increasing the dielectric constant of the dielectric layer 120 to a certain value, the amount of whisker-shaped high dielectric constant material B used in this embodiment can be less than that used with common granular materials. In other words, since the whisker-shaped high dielectric constant material B can more effectively improve the dielectric constant of the dielectric layer 120, in this embodiment, when preparing the dielectric layer 120 using the mixture, the mass percentage of the high dielectric constant material B in the mixture can be controlled at 0.5% to 1%.
[0048] Furthermore, by controlling the mass percentage of the high-dielectric-constant material B in the mixture to be above 0.5%, the dielectric constant of the dielectric layer 120 can be increased, thereby ensuring that the processing results of the wafer 200 meet the requirements. By controlling the mass percentage of the high-dielectric-constant material B in the mixture to below 1%, the dielectric constant of the dielectric layer 120 can be increased while maintaining the mass percentage of the insulating material A in the mixture, thereby ensuring the compactness and reliability of the dielectric layer 120.
[0049] Optionally, the mass percentage of the high dielectric constant material B in the mixture is 0.8% to 1%. Specifically, assuming that the dielectric constant of the dielectric layer prepared by using a single insulating material A in the prior art is x, then when the mass percentage of the high dielectric constant material B in the mixture in this embodiment is 1%, the dielectric constant of the dielectric layer 120 can be increased by 50%, that is, the dielectric constant of the dielectric layer 120 prepared in this embodiment is 1.5x.
[0050] Specifically, in one embodiment, the whiskers have a diameter greater than 8 nm and a length greater than 200 nm to ensure that the whisker-shaped high-dielectric-constant material B can better improve the dielectric constant of the dielectric layer 120; optionally, the whisker has a diameter of 10 nm to 20 nm and a length of 300 nm to 500 nm. Further, the high-dielectric-constant material B can be a carbide, including silicon carbide and boron carbide; optionally, the high-dielectric-constant material B is silicon carbide. In another embodiment, the high-dielectric-constant material B can also be a nitride, including silicon nitride and boron nitride, but the present invention is not limited thereto.
[0051] Specifically, in one embodiment, the insulating material A is aluminum oxide, yttrium oxide, or aluminum nitride. Optionally, the insulating material A is aluminum oxide. Further, the insulating material is granular to ensure the compactness of the dielectric layer 120. In another embodiment, the insulating material A may also be whisker-shaped, wherein the whiskers have a diameter greater than 8 nm and a length greater than 200 nm, but the present invention is not limited thereto.
[0052] Please continue to refer to this. Figure 2 In one embodiment, the dielectric layer 120 can be prepared using conventional processing methods (such as hot pressing, hot isostatic pressing, sintering, etc.). In this case, the high dielectric constant material B and the insulating material A can be mixed uniformly through a mixing process to ensure that the high dielectric constant material B and the insulating material A are uniformly distributed in the prepared dielectric layer 120.
[0053] Please continue to refer to this. Figure 3In another embodiment, the dielectric layer 120 can be prepared using a 3D printing process. In this case, the high dielectric constant material B and the insulating material A can be printed in layers so that the high dielectric constant material B and the insulating material A are alternately laid in the dielectric layer 120. Optionally, the (2n-1)th layer is the insulating material A and the 2nth layer is the high dielectric constant material B, where n = 1, 2, 3...N, and N is a positive integer.
[0054] Specifically, by using 3D printing to prepare the dielectric layer 120, the high dielectric constant material B can be orderly and controllably doped into the insulating material A. This avoids the uncontrollable diffusion of the high dielectric constant material B that may occur in conventional processing methods, thus ensuring the uniform distribution of the high dielectric constant material B in the dielectric layer 120, which is beneficial to improving the dielectric constant of the dielectric layer 120. Furthermore, by using 3D printing to prepare the dielectric layer 120, the amount of high dielectric constant material B and insulating material A added can also be controlled to control the thickness of each layer. This allows the high dielectric constant material B to be added at a specified location or depth, thereby locally adjusting the strength and electrical properties of the insulating material A.
[0055] Furthermore, depending on the specific application scenario, a dielectric layer 120 made of the mixture of the high dielectric constant material B and the insulating material A can be provided below the electrode layer 110, or other dielectric layers made of the single insulating material A can be provided below the electrode layer 110, but the present invention is not limited thereto.
[0056] On the other hand, combined with the appendix Figure 4 As shown, this embodiment also provides a semiconductor processing apparatus, including: a reaction chamber 210 and an electrostatic chuck 100 as described above; the electrostatic chuck 100 is disposed in the reaction chamber 210 and is used to carry and adsorb wafers 200.
[0057] Specifically, a spray head 220 is provided at the top of the reaction chamber 210 for introducing process gas into the reaction chamber 210; the spray head 220 is disposed opposite to the electrostatic chuck 100, and a reaction region is formed between the spray head 220 and the electrostatic chuck 100. More specifically, when processing the wafer 200, the electrostatic chuck 100 can serve as a lower electrode, the spray head 220 can serve as a lower electrode, and the upper electrode or the lower electrode is connected to a radio frequency power supply (not shown in the figure) to form a radio frequency electric field between the lower electrode and the upper electrode, thereby ionizing the process gas in the reaction region into plasma, and then processing the wafer 200.
[0058] On the other hand, combined with the attached Figure 5 As shown, this embodiment also provides a method for manufacturing an electrostatic chuck as described above, including: step S1, forming an electrode layer 110; step S2, preparing a dielectric layer 120 using a mixture comprising a high dielectric constant material B and an insulating material A; step S3, disposing the dielectric layer 120 on the electrode layer 110 and sintering the electrode layer 110 and the dielectric layer 120 together to form the electrostatic chuck 100.
[0059] In one embodiment, the dielectric layer 120 can be prepared using conventional processing methods (e.g., hot pressing, hot isostatic pressing, sintering, etc.); in this case, the step of preparing the dielectric layer 120, namely step S2, includes: step S21, mixing the high dielectric constant material B and the insulating material A uniformly; step S22, sintering the uniformly mixed high dielectric constant material B and the insulating material A together to form the dielectric layer 120.
[0060] In another embodiment, the dielectric layer 120 can be prepared using a 3D printing process; in this case, the step of preparing the dielectric layer 120, i.e., step S2, includes: step S21', preparing a 2n-1 layer using a 3D printing process and the insulating material A; n = 1, 2, 3...N, where N is a positive integer; step S22', preparing a 2n layer using a 3D printing process and the high dielectric constant material B, and laying the 2n layer on the 2n-1 layer; step S23', sintering the sequentially laid 2n-1 layer and the 2n layer together to form the dielectric layer 120.
[0061] In summary, this embodiment provides an electrostatic chuck, a semiconductor processing apparatus, and a manufacturing method. The electrostatic chuck includes an electrode layer and a dielectric layer disposed above the electrode layer. The dielectric layer is prepared using a mixture of a high-dielectric-constant material and an insulating material, wherein the dielectric constant of the high-dielectric-constant material is greater than that of the insulating material. Compared to the dielectric layer prepared using a single insulating material in the prior art, the dielectric layer prepared in this embodiment has a larger dielectric constant, resulting in increased capacitance and decreased impedance between the wafer and the electrostatic chuck. This leads to reduced radio frequency (RF) energy allocated to the electrostatic chuck and increased RF energy allocated to the sheath layer, thereby ensuring that the wafer processing results meet the requirements. In this embodiment, the high dielectric constant material is in the form of whiskers, which can more effectively improve the dielectric constant of the dielectric layer. Therefore, when the dielectric constant of the dielectric layer is increased to a certain value, compared to common granular materials, the amount of whisker-shaped high dielectric constant material used in this embodiment can be reduced. This allows the mass percentage of high dielectric constant material in the mixture to be controlled between 0.5% and 1%, thus achieving the goal of improving the dielectric constant of the dielectric layer while ensuring its density and reliability. In this embodiment, the whiskers have a diameter greater than 8 nm and a length greater than 200 nm to ensure that the whisker-shaped high dielectric constant material can better improve the dielectric constant of the dielectric layer. Furthermore, this embodiment can use 3D printing technology to prepare the dielectric layer. This allows the high dielectric constant material to be doped into the insulating material in an orderly and controllable manner, avoiding the uncontrollable diffusion of high dielectric constant material present in conventional processing methods. This ensures the uniform distribution of high dielectric constant material in the dielectric layer, which is beneficial for improving the dielectric constant of the dielectric layer.
[0062] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.
Claims
1. An electrostatic chuck, characterized in that, include: Electrode layer; A dielectric layer is disposed above the electrode layer; the dielectric layer is prepared from a mixture comprising a high dielectric constant material and an insulating material; The high dielectric constant material is in the form of whiskers, and the dielectric constant of the high dielectric constant material is greater than that of the insulating material; the mass percentage of the high dielectric constant material in the mixture is 0.5% to 1%.
2. The electrostatic chuck as described in claim 1, characterized in that, The high dielectric constant material and the insulating material are uniformly distributed in the dielectric layer.
3. The electrostatic chuck as described in claim 1, characterized in that, The high dielectric constant material and the insulating material are alternately laid in layers in the dielectric layer, and the (2n-1)th layer is the insulating material and the 2nth layer is the high dielectric constant material; n = 1, 2, 3...N, where N is a positive integer.
4. The electrostatic chuck as described in claim 1, characterized in that, The insulating material is in the form of granules.
5. The electrostatic chuck as described in claim 1, characterized in that, The insulating material is in the form of whiskers.
6. The electrostatic chuck as described in claim 1 or 5, characterized in that, The whisker has a diameter greater than 8 nm and a length greater than 200 nm.
7. The electrostatic chuck as described in claim 1, characterized in that, The high dielectric constant material is a carbide, which includes silicon carbide and boron carbide.
8. The electrostatic chuck as described in claim 1, characterized in that, The high dielectric constant material is a nitride, which includes silicon nitride and boron nitride.
9. The electrostatic chuck as described in claim 1, characterized in that, The insulating material is aluminum oxide, yttrium oxide, or aluminum nitride.
10. A semiconductor processing apparatus, characterized in that, include: reaction chamber; And an electrostatic chuck as described in any one of claims 1 to 9, wherein the electrostatic chuck is disposed within the reaction chamber.
11. A method for manufacturing an electrostatic chuck as described in any one of claims 1 to 9, characterized in that, include: Form an electrode layer; The dielectric layer is prepared using a mixture of high dielectric constant materials and insulating materials; The dielectric layer is disposed on the electrode layer and the electrode layer and the dielectric layer are sintered together to form the electrostatic chuck.
12. The method for manufacturing an electrostatic chuck as described in claim 11, characterized in that, The steps for preparing the dielectric layer include: The high dielectric constant material is mixed evenly with the insulating material; The high dielectric constant material, which is mixed uniformly, is sintered together with the insulating material to form the dielectric layer.
13. The method for manufacturing an electrostatic chuck as described in claim 11, characterized in that, The steps for preparing the dielectric layer include: The (2n-1)th layer is prepared using 3D printing technology and the aforementioned insulating material; n = 1, 2, 3…N, where N is a positive integer; The 2n-th layer is prepared using 3D printing technology and the high dielectric constant material, and the 2n-th layer is laid on the 2n-1-th layer; The 2n-1 layer and the 2n layer, laid in sequence, are sintered together to form the dielectric layer.