Electrostatic chuck and semiconductor processing apparatus

Abstract

The application discloses an electrostatic chuck and a semiconductor processing device, which comprises a base, a Peltier effect device and a controller. The Peltier effect device is provided with a plurality of temperature control zones, and the controller is used for controlling the Peltier effect device to perform zoned control on the temperature of the plurality of temperature control zones. The Peltier effect device is arranged on the base and is used for controlling the temperature of a wafer. The Peltier effect device comprises a plurality of semiconductor refrigeration crystals, the plurality of semiconductor refrigeration crystals are arranged in the plurality of temperature control zones, all the semiconductor refrigeration crystals in the same temperature control zone are connected in series, and the semiconductor refrigeration crystals in different temperature control zones are respectively controlled by electricity. The electrostatic chuck and the semiconductor processing device disclosed by the application can control the temperature of different regions of the wafer.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing technology, and more specifically, to an electrostatic chuck and semiconductor processing equipment. Background Technology

[0002] Electrostatic chucks are one of the core components in semiconductor equipment. They use an electrostatic force generator fixed to a base to generate Coulomb force or Jungs heat to hold and hold wafers. During plasma etching processes in semiconductor processing equipment, different regions of the wafer require different temperatures; therefore, temperature control of these different regions is necessary.

[0003] In existing technologies, temperature control in different wafer regions is achieved by altering the gas flow rate or type in different areas. However, this method requires an independently adjustable multi-zone gas distributor at the gas inlet. Furthermore, the differences in gas flow rate or type are partially diminished after diffusion from the gas distributor to the wafer surface, resulting in unsatisfactory temperature control across different wafer regions. Alternatively, temperature control can be achieved by adjusting the distribution of an electric field across the entire wafer surface. However, adjusting the electric field alters the plasma distribution, ultimately leading to unsatisfactory temperature control in different wafer regions as well.

[0004] Therefore, there is an urgent need for an electrostatic chuck that can control the temperature of different areas of a wafer. Summary of the Invention

[0005] This application provides an electrostatic chuck and semiconductor processing equipment that can control the temperature of different regions of a wafer.

[0006] To solve one or more of the above-mentioned technical problems, the technical solution adopted in this application is:

[0007] This application provides an electrostatic chuck, including: a base, a Peltier effect generating device, and a controller;

[0008] The Peltier effect generating device is provided with multiple temperature control zones, and the controller is used to control the Peltier effect generating device to perform zoned temperature control on the multiple temperature control zones.

[0009] The Peltier effect generating device is mounted on the base and is used to control the temperature of the wafer. The Peltier effect generating device includes multiple semiconductor cooling crystals, which are disposed in multiple temperature control zones. All semiconductor cooling crystals in the same temperature control zone are connected in series, and semiconductor cooling crystals in different temperature control zones are electrically controlled separately.

[0010] Furthermore, the electrostatic chuck also includes an electrostatic force generating device, which is disposed on the side of the Peltier effect generating device away from the base, and is used to adsorb the wafer.

[0011] Furthermore, the semiconductor cooling crystal includes an N-type semiconductor and a P-type semiconductor, with both ends of the N-type semiconductor and the P-type semiconductor connected to a metal sheet and arranged in series through the metal sheet.

[0012] Furthermore, the metal sheet includes a copper sheet.

[0013] Furthermore, the plurality of said semiconductor cooling crystals are distributed in a linear array or in a ring array.

[0014] Furthermore, the controller is used to control the current phase and magnitude between the N-type semiconductor and the P-type semiconductor to perform zoned temperature control of the plurality of temperature control zones.

[0015] Furthermore, the base is provided with a pipeline containing a circulating fluid, which is used to exchange heat with the Peltier effect generating device.

[0016] Furthermore, a substrate is provided on the side of the Peltier effect generating device away from the base, and a shielding ring extending toward the base is provided on the edge of the substrate. The base, the substrate, and the shielding ring form a receiving space for placing the Peltier effect generating device.

[0017] Furthermore, the electrostatic force generating device includes electrodes disposed in the substrate.

[0018] This application also provides a semiconductor processing apparatus, which includes a process chamber and the aforementioned electrostatic chuck is disposed within the process chamber.

[0019] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0020] This application provides an electrostatic chuck and semiconductor processing equipment. A Peltier effect generator is controlled by a controller to achieve zoned temperature control of multiple temperature control zones within the Peltier effect generator, ultimately realizing temperature control of different areas of the wafer. Specifically, the Peltier effect generator includes multiple thermoelectric coolers (SCUs) positioned within multiple temperature control zones. All SCUs within the same temperature control zone are connected in series, ensuring that all SCUs receive the same current intensity. This results in all SCUs within the same temperature control zone having the same cooling or heating effect at the same end, ultimately achieving a uniform temperature within the same temperature control zone. Alternatively, the SCUs in different temperature control zones are individually electrically controlled, allowing them to receive currents of varying intensities. This results in different cooling or heating effects for the SCUs in different temperature control zones, leading to different temperatures in each zone. In other words, by controlling the current intensity within different temperature control zones, the temperature of each zone is changed, ultimately achieving temperature control of different areas of the wafer.

[0021] Of course, any product implementing this application does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0023] Figure 1 This is a schematic diagram of the overall structure of the electrostatic chuck provided in the embodiments of this application;

[0024] Figure 2 This is a partial structural schematic diagram of the electrostatic chuck provided in an embodiment of this application;

[0025] Figure 3 This is a cross-sectional structural diagram of the electrostatic chuck provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art are within the scope of protection of this application.

[0027] As described in the background section, during plasma etching in semiconductor processing equipment, different regions of the wafer are required to have different temperatures. Therefore, temperature control of these different regions is necessary. One method is to change the gas flow rate or type in different regions of the wafer to control the temperature. However, this method requires an independently adjustable multi-zone gas distributor at the gas inlet. Furthermore, the differences in gas flow rate or type are partially reduced after diffusion from the gas distributor to the wafer surface, resulting in unsatisfactory temperature control in different regions. Another method is to adjust the distribution of the electric field across the entire wafer surface to control the temperature in different regions. However, adjusting the electric field causes changes in the plasma distribution, ultimately leading to unsatisfactory temperature control in different regions as well.

[0028] In response, this application provides an electrostatic chuck and semiconductor processing equipment, which uses a controller to control a Peltier effect generator to perform zoned temperature control of multiple temperature control zones in order to control the temperature of different areas of the wafer.

[0029] The following will describe the specific implementation examples.

[0030] Example 1

[0031] To address the aforementioned problems, this application presents an innovative electrostatic chuck, such as... Figure 1 As shown, and also refer to Figure 2 and Figure 3 The electrostatic chuck includes a base 100, a Peltier effect generating device 200, and a controller 700.

[0032] A Peltier effect generator 200 is mounted on the base 100 and is used to control the temperature of the wafer. The Peltier effect generator 200 is a semiconductor device that utilizes the Peltier effect to achieve both heating and cooling. The Peltier effect refers to the phenomenon that when current flows through a circuit composed of two different conductors, in addition to generating irreversible Joule heating, heat absorption and release occur at the junctions of the different conductors depending on the direction of the current. The heat absorption and release phenomena caused by the Peltier effect are reversible; when the direction of the current is changed, the junctions of heat absorption and release also change accordingly, and the heat absorbed and released is proportional to the current intensity.

[0033] Specifically, the Peltier effect generating device 200 is equipped with multiple temperature control zones, and the controller 700 is used to control the temperature of the multiple temperature control zones by the Peltier effect generating device 200. The Peltier effect generating device 200 includes multiple thermoelectric coolers, which are disposed within the multiple temperature control zones. All thermoelectric coolers within the same temperature control zone are connected in series, ensuring that all thermoelectric coolers within the same temperature control zone receive the same current intensity. This results in all thermoelectric coolers within the same temperature control zone having the same cooling or heating effect at the same end, ultimately leading to a uniform temperature within the same temperature control zone. The thermoelectric coolers in different temperature control zones are electrically controlled separately, allowing the thermoelectric coolers in different temperature control zones to receive different current intensities. This results in different cooling or heating effects for the thermoelectric coolers in different temperature control zones, leading to different temperatures in different temperature control zones. In other words, by controlling the current intensity in different temperature control zones, the temperature of different temperature control zones is changed, ultimately achieving temperature control in different areas.

[0034] Example 2

[0035] Based on Embodiment 1, this embodiment further refines the structure of the Peltier effect generating device 200.

[0036] The Peltier effect generating device 200 includes multiple semiconductor cooling crystals, each comprising an N-type semiconductor 210 and a P-type semiconductor 220. The two ends of each N-type semiconductor 210 and P-type semiconductor 220 are connected to a metal plate 230, which serves to conduct electricity and heat. The metal plate 230 connects multiple N-type semiconductors 210 and P-type semiconductors 220 in series. When an N-type semiconductor 210 and a P-type semiconductor 220 are connected through the metal plate 230 to form a semiconductor cooling crystal, a direct current is applied to this circuit, resulting in energy transfer. The current flows from the N-type semiconductor 210 to the P-type semiconductor 220 junction, absorbing heat and becoming the cold junction. The current flows from the P-type semiconductor 220 to the N-type semiconductor 210 junction, releasing heat and becoming the hot junction. The magnitude of heat absorption and release is determined by the magnitude of the current and the number of N-type semiconductors 210 and P-type semiconductors 220. Since the thermal effect produced by a single semiconductor cooling crystal is relatively small, multiple semiconductor cooling crystals need to be connected in series to produce a larger cooling or heating effect.

[0037] In one specific embodiment, the metal sheet 230 comprises a copper sheet. Of course, the metal sheet 230 can also be other metals with excellent thermal and electrical conductivity, such as aluminum or silver.

[0038] For the parts of Embodiment 2 that are not detailed, please refer to the descriptions in the foregoing embodiments, which will not be repeated here.

[0039] Example 3

[0040] Based on Embodiment 1 and Embodiment 2, this embodiment further refines the arrangement of the semiconductor cooling crystals.

[0041] In one specific embodiment, a plurality of semiconductor cooling crystals are arranged in a linear array of m rows and n columns, and the distribution of the plurality of temperature control zones on the Peltier effect generating device 200 corresponds to the distribution of the plurality of semiconductor cooling crystals. The controller 700 controls the temperature of the plurality of temperature control zones by controlling the current phase and magnitude between the N-type semiconductor 210 and the P-type semiconductor 220.

[0042] In another specific embodiment, the plurality of semiconductor cooling crystals are arranged in a ring array, and the specific number of rings can be set according to the actual required temperature control area. In this embodiment, multiple rings can be set to correspond to one temperature control zone, or one ring can be set to correspond to one temperature control zone. The controller 700 controls the temperature of the multiple temperature control zones by controlling the current phase and magnitude between the N-type semiconductor 210 and P-type semiconductor 220 in the multiple ring temperature control zones.

[0043] For the parts of Embodiment 3 that are not detailed, please refer to the descriptions in the foregoing embodiments, which will not be repeated here.

[0044] Example 4

[0045] The heat dissipation of the Peltier effect generator 200 is the basis for its long-term operation, and good heat dissipation is a prerequisite for obtaining the lowest cold end temperature.

[0046] In one specific embodiment, a pipe 400 is provided within the base 100, and a circulating fluid is provided within the pipe 400. This circulating fluid allows for heat exchange with the Peltier effect generator 200. More specifically, the coolant includes water, ethylene glycol, etc.; in this embodiment, water is preferred. The advantage of this heat exchange method is that the pipe 400 is located within the base 100, which does not increase the volume of the electrostatic chuck, and the heat dissipation effect is relatively good. The disadvantage is that using circulating fluid is inconvenient and wasteful.

[0047] In another specific embodiment, a material with good thermal conductivity, such as copper or aluminum, can be used to make a heat sink. This heat sink is placed below the hot end of the Peltier effect generator 200 to facilitate heat exchange. The advantage of this heat exchange method is its ease of use; the disadvantage is that it increases the size of the electrostatic chuck.

[0048] For the parts of Embodiment 4 that are not detailed, please refer to the descriptions in the foregoing embodiments, which will not be repeated here.

[0049] Example 5

[0050] To prevent wafers from shifting within the electrostatic chuck, the electrostatic chuck provided in this embodiment further includes an electrostatic force generating device 300, which can attract the wafers and prevent them from shifting. Specifically, the electrostatic force generating device 300 is located on the side of the Peltier effect generating device 200 away from the base 100.

[0051] In one specific embodiment, a substrate 500 is disposed on the side of the Peltier effect generating device 200 away from the base 100. A shielding ring 600 extending towards the base 100 is provided at the edge of the substrate 500. The base 100, substrate 500, and shielding ring 600 form a receiving space for housing the Peltier effect generating device 200. The substrate 500 and shielding ring 600 are made of ceramic. An electrostatic force generating device 300 is disposed in the substrate 500.

[0052] In another specific embodiment, the electrostatic force generating device 300 includes electrodes, which are disposed in the substrate 500 by sintering or spraying. When a wafer needs to be adsorbed, a fixed potential is applied to the electrodes, causing induced charges to be generated on the back side of the wafer, thereby attracting it to the electrostatic chuck.

[0053] Example 6

[0054] Based on Embodiments 1 to 5, this embodiment also provides a semiconductor processing apparatus, which includes a process chamber in which the aforementioned electrostatic chuck is disposed.

[0055] The electrostatic chuck and semiconductor processing equipment provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An electrostatic chuck, characterized in that, include: Base, Peltier effect generating device and controller; The Peltier effect generating device is provided with multiple temperature control zones, and the controller is used to control the Peltier effect generating device to perform zoned temperature control on the multiple temperature control zones. The Peltier effect generating device is mounted on the base and is used to control the temperature of the wafer. The Peltier effect generating device includes multiple semiconductor cooling crystals, which are disposed in multiple temperature control zones. All semiconductor cooling crystals in the same temperature control zone are connected in series, and semiconductor cooling crystals in different temperature control zones are electrically controlled separately. The semiconductor cooling crystal includes an N-type semiconductor and a P-type semiconductor. The two ends of the N-type semiconductor and the P-type semiconductor are respectively connected to a metal sheet and are connected in series through the metal sheet. The plurality of said semiconductor cooling crystals are arranged in a linear array or in a ring array; The controller is used to control the current phase and magnitude between the N-type semiconductor and the P-type semiconductor to perform zoned temperature control of the multiple temperature control zones. The electrostatic chuck also includes an electrostatic force generating device, which is disposed on the side of the Peltier effect generating device away from the base, and is used to adsorb the wafer. The Peltier effect generating device has a substrate on the side away from the base, and the edge of the substrate has a shielding ring extending toward the base. The base, the substrate and the shielding ring form a receiving space for placing the Peltier effect generating device. The electrostatic force generating device includes electrodes disposed in the substrate.

2. The electrostatic chuck according to claim 1, characterized in that, The metal sheet includes a copper sheet.

3. The electrostatic chuck according to claim 1, characterized in that, The base is provided with a pipeline, and the pipeline is provided with a circulating fluid, which is used to exchange heat with the Peltier effect generating device.

4. A semiconductor processing apparatus, characterized in that, It includes a process chamber, wherein an electrostatic chuck as described in any one of claims 1 to 3 is disposed within the process chamber.

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