Electrostatic chuck and three-dimensional partition temperature control apparatus comprising same, cooling method

Abstract

This invention discloses an electrostatic chuck and a three-dimensional zoned temperature control device incorporating the electrostatic chuck. The electrostatic chuck includes a three-dimensional cooling pipeline system, comprising upper and lower cooling pipelines, each with its own independent temperature control via an upper and lower circulation system. Furthermore, it offers three operating modes based on the relative temperature values ​​of the upper and lower circulation systems. The electrostatic chuck and the three-dimensional zoned temperature control device incorporating the electrostatic chuck of this invention significantly improve response speed, enable precise temperature adjustment, significantly enhance temperature uniformity, reduce energy consumption, and are suitable for various processes.

Description

Technical Field

[0001] This invention relates to the field of electrostatic chucks, and more specifically, to an electrostatic chuck including a three-dimensional cooling pipeline system, and a three-dimensional zoned temperature control device and cooling method comprising the same. Background Technology

[0002] Electrostatic chucks are core components in semiconductor manufacturing processes, widely used in equipment for plasma etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), and ion implantation. Their main function is to fix wafers in a vacuum environment using electrostatic adsorption forces and precisely control the temperature during wafer processing. As semiconductor process nodes evolve towards 5 nanometers and below, wafer temperature uniformity and response speed have become key factors affecting etching rate consistency, thin film quality, and device yield.

[0003] Currently, most mainstream electrostatic chucks adopt a single-layer cooling pipe design, which involves setting a single-layer flow channel within the electrostatic chuck to remove heat conducted from the wafer by circulating coolant. However, the single-layer cooling solution has the following inherent limitations in application: 1) Delayed axial heat conduction: The single-layer cooling pipe is usually located in the lower part of the chuck body, far from the wafer bearing surface (usually more than 10 mm), resulting in a long heat conduction path, high thermal resistance, and slow response to changes in wafer surface temperature; 2) Limited control dimensions: The single-layer cooling solution can only optimize the temperature distribution in the horizontal plane (XY plane), and cannot actively control the temperature gradient in the wafer thickness direction (Z-axis). Existing single-layer solutions cannot establish and adjust the axial temperature gradient; 3) Energy efficiency needs improvement: To achieve the required cooling effect, the single-layer cooling system usually requires a large coolant flow rate and high pumping power, and the heat must be conducted from the wafer to the bottom pipe in one go, resulting in low heat exchange efficiency and high overall energy consumption. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention proposes an electrostatic chuck with a three-dimensional cooling pipeline system, a three-dimensional partitioned temperature control device containing the chuck, and a cooling method thereof. By using an upper and lower layer of independently temperature-controlled cooling pipeline system, combined with a fast-response upper microchannel and a lower large-section channel for primary heat dissipation, a controllable axial temperature gradient is established in the wafer thickness direction, achieving multi-dimensional and precise control of the wafer temperature field. This improves temperature uniformity, accelerates response speed, enhances process adaptability, and reduces energy consumption.

[0005] A first aspect provides an electrostatic chuck, which includes a metal base and a ceramic disk;

[0006] A three-dimensional cooling pipeline system is formed in the metal base, the three-dimensional cooling pipeline system including upper cooling pipeline and lower cooling pipeline;

[0007] The thickness of the electrostatic chuck is H1, the distance between the upper cooling pipe and the upper surface of the electrostatic chuck metal base is H2, the distance between the lower cooling pipe and the upper cooling pipe is H3, the ratio of H2 to H1 is 1:100 to 1:1.5, and the ratio of H3 to H1 is 1:100 to 1:3.

[0008] The upper and lower cooling pipes are selected from vortex, radial fan, and reciprocating ring shapes; the upper cooling pipe is a microchannel with a characteristic dimension of 0.1 to 1.0 mm; the lower cooling pipe is a large-section channel with a characteristic dimension ratio of 2:1 to 10:1 to the microchannel; the center distance between adjacent microchannels is D1, and the center distance between adjacent large-section channels is D2, with the ratio of D1 to D2 being 1:2.5 to 1:250;

[0009] The ceramic disc is bonded to the upper surface of the metal base;

[0010] Furthermore, the electrostatic chuck has a diameter of 200 to 480 mm and a thickness of 20 to 50 mm;

[0011] The projected areas of the upper and lower cooling pipes on the horizontal plane each account for 0.3 to 1% of the surface area of ​​the electrostatic chuck.

[0012] Furthermore, the cross-sections of the upper and lower cooling pipes are circular or square;

[0013] The inlets and outlets of the upper and lower cooling pipes are located independently on the edge or in the center of the electrostatic chuck.

[0014] The number of inlets and outlets of the upper cooling pipe and the lower cooling pipe are each independently 1 to 3.

[0015] The second aspect provides a three-dimensional zoned temperature control device including the electrostatic chuck described in the first aspect, and further includes a circulation system, the circulation system including an upper circulation system and a lower circulation system;

[0016] The upper cooling pipeline of the electrostatic chuck is temperature controlled by an upper circulation system, which includes a high-precision gear pump and a Peltier semiconductor temperature control module, with a flow rate range of 0.1 to 5 L / min and a temperature control accuracy of ± 0.05 ℃.

[0017] The lower cooling pipeline of the electrostatic chuck is temperature controlled by a lower circulation system, which includes a centrifugal pump and a compressor refrigeration system, with a flow rate range of 5 to 20 L / min and a temperature control accuracy of ± 0.1 ℃.

[0018] Furthermore, the set temperature of the upper circulation system is T1, and the set temperature of the lower circulation system is T2, with the numerical range of both T1 and T2 being -20 to 200 ℃.

[0019] Furthermore, the temperature control modes of the device include positive temperature gradient mode, reverse temperature gradient mode, and standard uniform cooling mode.

[0020] The positive temperature gradient mode is T1 < T2, the negative temperature gradient mode is T1 > T2, and the standard uniform cooling mode is T1 = T2;

[0021] Furthermore, the specific heat capacity of the coolant in the upper circulation system is lower than that of the coolant in the lower circulation system, and the thermal conductivity of the coolant in the upper circulation system is lower than that of the coolant in the lower circulation system.

[0022] Furthermore, the coolant in the upper circulation system is selected from one of fluorinated liquid and water / ethylene glycol mixture; the coolant in the lower circulation system is selected from one of fluorinated liquid and water / ethylene glycol mixture.

[0023] A third aspect provides a cooling method for the three-dimensional zoned temperature control device described in the second aspect, comprising the following steps:

[0024] (1) Select the positive temperature gradient mode, the reverse temperature gradient mode, or the standard uniform cooling mode according to the process type;

[0025] (2) Set the target temperature and flow rate of the upper and lower circulation systems independently;

[0026] (3) Perform self-cleaning and maintenance procedures regularly.

[0027] Beneficial effects:

[0028] 1. The electrostatic chuck of the present invention uses two layers of independently temperature-controlled cooling pipes. By controlling the position, feature size, and distance between adjacent pipes, the upper layer of dense microchannels shortens the heat conduction path, significantly improves the response speed, and enables precise temperature adjustment. The lower layer of large-section channels undertakes the main heat dissipation function and actively regulates the axial temperature gradient. Furthermore, by controlling the projected area of ​​the cooling pipes, the number and position of the inlet / outlet, and the relative magnitude of the specific heat capacity and thermal conductivity of the upper and lower layers of coolant, high-precision control of wafer surface temperature is achieved, temperature uniformity is significantly improved, and energy consumption is reduced.

[0029] 2. The three-dimensional temperature control device of this invention has three temperature control modes, suitable for different processes: positive temperature gradient mode, in which a heat flow direction from top to bottom is formed between the wafer and the temperature control device, suitable for plasma etching process, which can quickly remove surface reaction heat, achieve uniform temperature, and obtain a steeper and smoother etching morphology; reverse temperature gradient mode, in which a heat flow direction from bottom to top is formed between the wafer and the temperature control device, suitable for CVD deposition process, with good film thickness uniformity, adjustable film stress, reduced wafer warpage, and fewer defects; standard uniform mode has good temperature uniformity and uniform film thickness, suitable for processes with extremely high temperature stability requirements such as atomic layer deposition. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the operation of a three-dimensional zoned temperature control device;

[0032] Figure 2 This is a schematic diagram of a vortex-shaped cooling pipe system.

[0033] Figure 3 This is a schematic diagram of a radial, fan-shaped cooling pipe system.

[0034] Figure 4 This is a schematic diagram of a reciprocating, circular cooling pipeline.

[0035] Figure 5 A schematic diagram showing that the inlet and outlet of the cooling pipes are located independently on the edge or in the center of the electrostatic chuck;

[0036] 1-Electrostatic chuck, 11-Metal base, 12-Ceramic disk, 13-Upper cooling pipe, 14-Lower cooling pipe, 15-Cooling gas chamber, 2-Upper circulation system, 3-Lower circulation system, 4-Wafer;

[0037] Figure 2-5 The single arrow in the diagram represents the flow direction of the coolant in the cooling pipes. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that the feature dimensions in this invention refer to the diameter for circles and the side length for rectangles; "three-dimensional cooling pipeline system" refers to cooling pipelines with independent temperature control on both the upper and lower layers.

[0040] The first aspect of this invention provides an electrostatic chuck. Figure 1 This is a schematic diagram of the operation of an electrostatic chuck. (For reference) Figure 1 The electrostatic chuck 1 includes a metal base 11 and a ceramic disk 12 bonded thereto. A three-dimensional cooling pipeline system is formed within the metal base 11, comprising an upper cooling pipeline 13 and a lower cooling pipeline 14. The electrostatic chuck 1 also includes a cooling gas chamber 15. An upper circulation system 2 and a lower circulation system 3 are externally connected to the electrostatic chuck 1, and a wafer is located at 4.

[0041] In this design, heat transfer in both the upper cooling pipe 13 and the lower cooling pipe 14 occurs through gas within the cooling gas chamber 15, which can be a gas such as helium. The electrostatic chuck has a thickness of H1, the distance between the upper cooling pipe and the upper surface of the electrostatic chuck's metal base is H2, and the distance between the lower cooling pipe and the upper cooling pipe is H3. The ratio of H2 to H1 is 1:100 to 1:1.5, and the ratio of H3 to H1 is 1:100 to 1:3. The upper cooling pipe 13 is close to the heat source, shortening the heat conduction path and quickly absorbing or providing heat. The lower cooling pipe 14 undertakes the main heat dissipation function, forming an efficient heat transfer path.

[0042] The upper cooling pipe 13 is a microchannel with a characteristic dimension of 0.1 to 1.0 mm. The lower cooling pipe 14 is a large-section channel with a characteristic dimension ratio of 2:1 to 10:1 to the microchannel. The center distance between adjacent microchannels is D1, and the center distance between adjacent large-section channels is D2. The ratio of D1 to D2 is 1:2.5 to 1:250, thereby significantly improving the response speed of the microchannels and allowing the large-section channels to handle the main heat dissipation.

[0043] The electrostatic chuck 1 has a diameter of 200 to 480 mm and a thickness of 20 to 50 mm. The projected areas of the upper cooling pipe 13 and the lower cooling pipe 14 on the horizontal plane each occupy 0.3 to 1 of the surface area of ​​the electrostatic chuck 1. This arrangement aims to achieve uniform cooling of the entire wafer surface and precise control of the axial temperature gradient.

[0044] Reference Figure 2 or Figure 3 The upper cooling pipe 13 and the lower cooling pipe 14 are selected from vortex, radial fan, or reciprocating ring shapes. The inlet and outlet of the upper cooling pipe 13 and the lower cooling pipe 14 are independently located at the edge of the electrostatic chuck 1, or they can be located in the central area. The number of inlets and outlets of the upper cooling pipe 13 and the lower cooling pipe 14 are each independently 1 to 3. The cross-section of the upper cooling pipe 13 and the lower cooling pipe 14 is circular or square.

[0045] A second aspect of the present invention provides a three-dimensional zoned temperature control device, including the aforementioned electrostatic chuck 1 and a circulation system. The circulation system includes an upper circulation system 2 and a lower circulation system 3. The upper cooling pipe 13 is temperature-controlled through the upper circulation system 2, which includes a high-precision gear pump and a Peltier semiconductor temperature control module, with a flow rate range of 0.1 to 5 L / min and a temperature control accuracy of ±0.05 ℃. The lower cooling pipe 14 is temperature-controlled through the lower circulation system 3, which includes a centrifugal pump and a compressor refrigeration system, with a flow rate range of 5 to 20 L / min and a temperature control accuracy of ±0.1 ℃.

[0046] The upper circulation system 2 is set to temperature T1, and the lower circulation system 3 is set to temperature T2. Both T1 and T2 range from -20 to 200 °C. The three-dimensional zoned temperature control equipment can flexibly meet various operating modes: positive temperature gradient mode, reverse temperature gradient mode, and standard uniform cooling mode. In positive temperature gradient mode, T1 < T2; in reverse temperature gradient mode, T1 > T2; and in standard uniform cooling mode, T1 = T2. Different operating modes are selected depending on the process, including but not limited to: in plasma etching, selecting positive temperature gradient mode can quickly remove surface reaction heat, resulting in a steeper and smoother etching morphology; in CVD deposition, selecting reverse temperature gradient mode can control film stress and reduce wafer warpage; and in processes with extremely high temperature stability requirements, such as atomic layer deposition, selecting standard uniform mode can eliminate axial temperature gradients.

[0047] Based on the process temperature range and precision requirements, the specific heat capacity of the coolant in the upper circulation system 2 is lower than that of the coolant in the lower circulation system 3, and the thermal conductivity of the coolant in the upper circulation system 2 is lower than that of the coolant in the lower circulation system 3. The coolant in the upper circulation system 2 is selected from either a fluorinated liquid or a water / ethylene glycol mixture; the coolant in the lower circulation system 3 is selected from either a fluorinated liquid or a water / ethylene glycol mixture. Preferably, the upper circulation system 2 uses a fluorinated liquid as the coolant, utilizing its low specific heat capacity, low thermal conductivity, and high insulation to ensure the rapid response of the upper circulation system and the safety of the area near the electrodes. The lower circulation system 3 uses a water / ethylene glycol mixture, utilizing its high specific heat capacity and high thermal conductivity to improve heat dissipation efficiency.

[0048] A third aspect of the present invention also provides a cooling method for a three-dimensional zoned temperature control device as described in the second aspect of the present invention, comprising the following steps:

[0049] (1) Select the positive temperature gradient mode, the reverse temperature gradient mode, or the standard uniform cooling mode according to the process type;

[0050] (2) Set the target temperature and flow rate of the upper cooling pipe 13 and the lower cooling pipe 14 independently;

[0051] (3) Perform self-cleaning procedures regularly.

[0052] In semiconductor processes (such as etching and CVD), process gases can generate unwanted reaction products, such as polymers and byproducts, on the chuck surface. Self-cleaning achieves this by using the low temperatures of a three-dimensional cooling pipeline system to "freeze" the deposits on the chuck surface, causing them to detach and thus achieving self-cleaning.

[0053] The above and other advantages of the present invention can be better understood through the following embodiments, but the following embodiments are not intended to limit the scope of the present invention.

[0054] Example

[0055] The following embodiments illustrate the present invention, but the present invention is not limited to the following embodiments.

[0056] Temperature uniformity test:Forty-nine test points were marked on the wafer surface (seven concentric circles were set along the radius, with radii of 0mm, 25mm, 50mm, 75mm, 100mm, 125mm and 150mm, and several points were evenly distributed on each circle). A FLIRA6750sc infrared thermal imager was used in conjunction with five PT1000 Class AA platinum resistance temperature sensors for calibration and verification. Data was continuously collected for 10 minutes using an NI PXIe-1073 chassis with an NI PXIe-4353 temperature acquisition module. The average value was then taken to obtain the overall average temperature of the 49 points and the deviation of each point. The absolute value of the maximum deviation was taken as the temperature uniformity index.

[0057] Etching rate uniformity test: The initial film thickness of each point on the wafer (49 test points, the selection of points is the same as in the "Wafer Surface Temperature Uniformity Test") was recorded. After etching, the final film thickness of the 49 points was measured again using an ellipsometry. The etching thickness and etching rate of each point were calculated, and then the average value and standard deviation (1σ) of the etching rate of the 49 points were obtained. Finally, the percentage of the standard deviation divided by the average value was used as the etching rate uniformity index.

[0058] Temperature response time test: A miniature K-type thermocouple is attached to the center of the chuck bearing surface and fixed with thermally conductive adhesive. It is then connected to an NI PXIe-1073 chassis with an NI PXIe-4309 high-speed acquisition card. The initial temperature of the upper cooling pipe in the embodiment is set to 10°C and the lower temperature is set to 10°C. The initial temperature of the cooling pipe in the comparative example is also set to 10°C. After the chuck surface temperature stabilizes, the target temperature is changed to 20°C (step amplitude of 10°C). At the same time, the data acquisition system is triggered to continuously record the temperature change at a sampling rate of 1kHz for at least 20 seconds until it stabilizes again. The test is repeated 3 times and the average value is taken. The initial temperature and steady-state temperature are determined according to the step response curve. The 63.2% response temperature value (initial temperature + 0.632 × step amplitude) is calculated. The moment when the temperature first reaches this value is found, and the time difference between this moment and the moment when the step is applied is recorded.

[0059] Energy consumption test: Connect the Yokogawa WT5000 power analyzer to the power supply circuit of the temperature control system, monitor the power of the circulation system, and continuously record the instantaneous power for 30 minutes (sampling interval 10ms). After the test, calculate the total energy consumption by integration.

[0060] Thin film thickness uniformity test: Using a JA Woollam M-2000XI fully automatic elliptic polarization spectrometer, with the incident angle set to 65°, the 49-point test mode was selected in the instrument control software. Automatic scanning measurement was then initiated, and the software automatically output the thickness values ​​of the 49 measurement points and calculated the uniformity.

[0061] Thin film stress testing: The initial radius of curvature of a blank wafer without a deposited thin film was measured using the SM300_i fully automatic wafer warp stress measuring instrument manufactured by Suzhou Ruifei Optoelectronics Technology Co., Ltd. The sampling interval was set to 0.1 mm. The wafer after the deposited thin film was measured under the same conditions to obtain the radius of curvature after coating. The instrument software automatically calculated the film stress value. The measurement was repeated 5 times and the average value was taken.

[0062] Wafer warpage testing: The SM300_i fully automatic wafer warpage stress measuring instrument is used, with a wide wavelength light source from 400 to 760 nm. The sampling interval can be set to 0.1 mm, and the software automatically outputs the warpage parameters.

[0063] Thin film refractive index testing: Using a JA Woollam M-2000XI fully automatic elliptic polarization spectrometer, the incident angle was set to 65°. The refractive index measurement mode was selected in the instrument control software, an optical model including the thin film layer and the substrate was established and fitted, and the software automatically output the refractive index value of the thin film at 632.8 nm. The measurement was repeated 5 times at different positions of the sample and the average value was taken.

[0064] Defect density test: Using the KLA-Tencor Surfscan SP5 series, a 405nm wavelength laser beam is used to scan the entire wafer surface at a fixed incident angle of 70°. The device automatically records the coordinates and dimensions of the defects, and the software calculates the total number of defects on the entire wafer surface and divides it by the effective area of ​​the wafer to calculate the defect density.

[0065] Example 1

[0066] The electrostatic chuck has a diameter of 330 mm and a thickness of 35 mm. It is an alumina ceramic disk. The upper cooling channel has a circular cross-section with a diameter of 0.5 mm, arranged in a radial fan shape. The center-to-center distance between adjacent microchannels is 5 mm, and the distance from the upper surface of the electrostatic chuck's metal base is 1 mm. The lower cooling channel has a circular cross-section with a diameter of 3 mm, a vortex design, and is located 10 mm from the upper cooling channel. The center-to-center distance between adjacent large-section channels is 30 mm. The projected area of ​​both the upper and lower cooling channels on the horizontal plane occupies 0.6 of the electrostatic chuck's disk area (this can be directly obtained from drafting software). The inlets and outlets of both the upper and lower cooling channels are located at the edge of the electrostatic chuck, and each channel is an independent single-channel connected in series.

[0067] Employing a positive temperature gradient mode, the upper circulation system is set to 10℃, and the lower circulation system to 20℃. The upper cooling lines are temperature-controlled via the upper circulation system, using a high-precision gear pump with a flow rate of 0.5 to 3 L / min and a Peltier semiconductor temperature control module, achieving a temperature control accuracy of ±0.05℃. The lower cooling lines are temperature-controlled via the lower circulation system, using a centrifugal pump with a flow rate of 8 to 15 L / min and a combined compressor refrigeration and electric heating temperature control system, achieving a temperature control accuracy of ±0.1℃. The upper circulation system uses fluorinated liquid as the coolant, while the lower circulation system uses a water / ethylene glycol mixture.

[0068] The above electrostatic chuck is used to perform plasma etching on a 12-inch wafer. The process gas is a mixture of CF4 / O2 / Ar, the chamber pressure is 50 mTorr, the RF power is 3000 W (13.56 MHz), and the helium back pressure is 15 Torr.

[0069] Comparative Example 1

[0070] The electrostatic chuck has a diameter of 330 mm and a thickness of 35 mm. It is an alumina ceramic disc with only one layer of cooling tubing. The cooling tubing has a circular cross-section, a diameter of 3 mm, and a vortex design. The distance between the cooling tubing and the upper surface of the electrostatic chuck's metal base is 10 mm, and the center-to-center distance between adjacent cooling tubing is 30 mm. The projected area of ​​each cooling tubing on the horizontal plane occupies 0.6 times the surface area of ​​the electrostatic chuck (this can be directly obtained from drafting software). The inlet and outlet of the cooling tubing are both located at the edge of the electrostatic chuck, forming a single, series-connected flow channel.

[0071] The circulating system is set to 10℃. The cooling pipes are temperature-controlled through the circulating system, using a centrifugal pump with a flow rate of 8 to 15 L / min. A combined compressor refrigeration and electric heating temperature control system is used, with a temperature control accuracy of ±0.1℃. Fluorinated liquid is used as the coolant.

[0072] The above electrostatic chuck is used to perform plasma etching on a 12-inch wafer. The process gas is a mixture of CF4 / O2 / Ar, the chamber pressure is 50 mTorr, the RF power is 3000 W (13.56 MHz), and the helium back pressure is 15 Torr.

[0073] The performance tests conducted on the above embodiments and comparative examples are shown in Table 1.

[0074] Table 1

[0075] Test Project Example 1 Comparative Example 1 Temperature uniformity / ℃ ±0.25 ±2.8 Etching rate uniformity / % (1σ) ≤1.8 ≤5.2 Temperature response time / s 0.8 8.5 Energy consumption benchmark 28%

[0076] Example 2

[0077] Except for the following differences, it is the same as Example 1:

[0078] Employing a reverse temperature gradient mode, the upper circulation system is set to 120℃, and the lower circulation system is set to 80℃. The upper cooling pipes are temperature-controlled via the upper circulation system, using a high-precision gear pump with a flow rate of 0.3 to 2 L / min, a Peltier semiconductor temperature control module, and auxiliary electric heating, achieving a temperature control accuracy of ±0.08℃. The lower cooling pipes are temperature-controlled via the lower circulation system, using a centrifugal pump with a flow rate of 6 to 12 L / min, and a combined compressor refrigeration and electric heating temperature control system, achieving a temperature control accuracy of ±0.15℃.

[0079] The electrostatic chuck above was used to perform PECVD deposition on a 12-inch wafer. The process gas was SiH4 / NH3 / N2, the chamber pressure was 2 Torr, the RF power was 600 W (13.56 MHz), the deposition time was 180 seconds, and the helium back pressure was 10 Torr.

[0080] Comparative Example 2

[0081] Except for the following differences, it is the same as Comparative Example 1:

[0082] The cooling pipes are set to a temperature of 100℃.

[0083] The electrostatic chuck above was used to perform PECVD deposition on a 12-inch wafer. The process gas was SiH4 / NH3 / N2, the chamber pressure was 2 Torr, the RF power was 600 W (13.56 MHz), the deposition time was 180 seconds, and the helium back pressure was 10 Torr.

[0084] The performance tests conducted on the above embodiments and comparative examples are shown in Table 2.

[0085] Table 2

[0086] Test Project Example 2 Comparative Example 2 Film thickness uniformity / % ±1.2 ±3.5 Thin film stress / MPa (tensile stress) 350 1200 Wafer warpage / μm <30 <85 Thin film refractive index 2.01±0.02 2.05±0.08 <![CDATA[Defect density / number / cm 2 > <0.03 <0.12

[0087] Example 3

[0088] Except for the following differences, it is the same as Example 1:

[0089] The system employs a standard uniform cooling mode, with both the upper and lower cooling systems set at 150℃. The upper cooling piping is temperature-controlled via the upper cooling system, using a gear pump with a flow rate of 0.3 to 2 L / min, a Peltier semiconductor temperature control module, and auxiliary electric heating, achieving a temperature control accuracy of ±0.05℃. The lower cooling piping is temperature-controlled via the lower cooling system, using a centrifugal pump with a flow rate of 6 to 12 L / min, and compressor cooling, achieving a temperature control accuracy of ±0.10℃.

[0090] Atomic layer deposition was performed on a 12-inch wafer using an electrostatic chuck. The precursor was TMA (trimethylaluminum) / H2O (for Al2O3 deposition). The chamber pressure was 1 Torr, the deposition temperature was 150°C, the number of cycles was 500 (target film thickness 50 nm), and the helium back pressure was 12 Torr.

[0091] Comparative Example 3

[0092] Except for the following differences, it is the same as Comparative Example 1:

[0093] The set temperature for the circulation system is 150℃.

[0094] Atomic layer deposition was performed on a 12-inch wafer using an electrostatic chuck. The precursor was TMA (trimethylaluminum) / H2O (for Al2O3 deposition). The chamber pressure was 1 Torr, the deposition temperature was 150°C, the number of cycles was 500 (target film thickness 50 nm), and the helium back pressure was 12 Torr.

[0095] The performance tests conducted on the above embodiments and comparative examples are shown in Table 3.

[0096] Table 3

[0097] Test Project Example 3 Comparative Example 3 Temperature uniformity / ℃ ±0.15 ±1.2 Film thickness uniformity / % ±1.3 ±4.0

[0098] It should be noted that, based on the explanations and descriptions in the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some equivalent modifications and alterations to the present invention should also be within the scope of protection of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the invention.

Claims

1. An electrostatic chuck, characterized in that, It includes a metal base and a ceramic disc bonded to its upper surface; A three-dimensional cooling pipeline system is formed in the metal base, the three-dimensional cooling pipeline system including upper cooling pipeline and lower cooling pipeline; The thickness of the electrostatic chuck is H1, the distance between the upper cooling pipe and the upper surface of the electrostatic chuck metal base is H2, the distance between the lower cooling pipe and the upper cooling pipe is H3, the ratio of H2 to H1 is 1:100 to 1:1.5, and the ratio of H3 to H1 is 1:100 to 1:

3. The upper and lower cooling pipes are selected from vortex, radial fan, and reciprocating ring shapes; the upper cooling pipe is a microchannel with a characteristic dimension of 0.1 to 1.0 mm; the lower cooling pipe is a large-section channel with a characteristic dimension ratio of 2:1 to 10:1 to the microchannel; the center distance between adjacent microchannels is D1, and the center distance between adjacent large-section channels is D2, with the ratio of D1 to D2 being 1:2.5 to 1:

250.

2. The electrostatic chuck according to claim 1, characterized in that, The electrostatic chuck has a diameter of 200 to 480 mm and a thickness of 20 to 50 mm; The projected areas of the upper and lower cooling pipes on the horizontal plane each account for 0.3 to 1% of the surface area of ​​the electrostatic chuck.

3. The electrostatic chuck according to claim 1, characterized in that, The cross-sections of the upper and lower cooling pipes are circular or square. The inlets and outlets of the upper and lower cooling pipes are located independently on the edge or in the center of the electrostatic chuck. The number of inlets and outlets of the upper cooling pipe and the lower cooling pipe are each independently 1 to 3.

4. A three-dimensional zoned temperature control device comprising the electrostatic chuck according to any one of claims 1 to 3, characterized in that, It also includes a circulation system, which comprises an upper circulation system and a lower circulation system; The upper cooling pipeline of the electrostatic chuck is temperature controlled by an upper circulation system, which includes a high-precision gear pump and a Peltier semiconductor temperature control module, with a flow rate range of 0.1 to 5 L / min and a temperature control accuracy of ± 0.05 ℃. The lower cooling pipeline of the electrostatic chuck is temperature-controlled through a lower circulation system, which includes a centrifugal pump and a compressor refrigeration system, with a flow rate range of 5 to 20 L / min and a temperature control accuracy of ± 0.1 ℃.

5. The three-dimensional zoned temperature control device according to claim 4, characterized in that, The set temperature of the upper circulation system is T1, and the set temperature of the lower circulation system is T2. The numerical range of both T1 and T2 is -20 to 200℃.

6. The three-dimensional zoned temperature control device according to claim 5, characterized in that, The temperature control modes of the device include positive temperature gradient mode, reverse temperature gradient mode, and standard uniform cooling mode; The positive temperature gradient mode is T1 < T2, the negative temperature gradient mode is T1 > T2, and the standard uniform cooling mode is T1 = T2.

7. The three-dimensional zoned temperature control device according to claim 4, characterized in that, The specific heat capacity of the coolant in the upper circulation system is lower than that of the coolant in the lower circulation system, and the thermal conductivity of the coolant in the upper circulation system is lower than that of the coolant in the lower circulation system.

8. The three-dimensional zoned temperature control device according to claim 7, characterized in that, The coolant in the upper circulation system is selected from one of fluorinated liquid and water / ethylene glycol mixture; the coolant in the lower circulation system is selected from one of fluorinated liquid and water / ethylene glycol mixture.

9. A cooling method for a three-dimensional zoned temperature control device according to any one of claims 4 to 8, characterized in that, Includes the following steps: (1) Select the positive temperature gradient mode, the reverse temperature gradient mode, or the standard uniform cooling mode according to the process type; (2) Set the target temperature and flow rate of the upper and lower circulation systems independently; (3) Perform self-cleaning and maintenance procedures regularly.

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