Surface topography flattening apparatus and method of improving electrostatic chuck topography flatness

Abstract

The application discloses a surface topography flattening device, comprising: an electrostatic chuck with a surface to be polished; a temperature control part arranged opposite to the surface to be polished; a polishing piece with a polishing surface used for contacting the surface to be polished of the electrostatic chuck; the temperature control part is used for heating or cooling the polishing piece, so that the polishing piece is heated to expand or cooled to shrink, and the polishing surface of the polishing piece polishes the surface to be polished of the electrostatic chuck. The surface topography flattening device can polish the surface of the electrostatic chuck.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a surface topography smoothing device and a method for improving the surface topography smoothness of an electrostatic chuck. Background Technology

[0002] The JR (Johnsen-Rahbek) type electrostatic chuck (ESC) currently in use can generate a large electrostatic adsorption force when a relatively low voltage is provided. During its fabrication, Al2O3 powder doped with elements such as Mg, Si, and Ti needs to be sintered and shaped. Inevitably, the surface state of the ESC will be uneven during the shaping process, which will affect the temperature uniformity of the wafer adsorbed on the ESC in the plasma etching process, and directly affect the uniformity of the etching result. Summary of the Invention

[0003] The purpose of this invention is to provide a surface morphology smoothing device and a method for improving the surface morphology smoothness of an electrostatic chuck. The surface morphology smoothing device forms a hot-cold cycle by repeatedly switching the heating device and the first cooling device, causing the polished part to expand or contract, and using the polishing surface to polish the surface to be polished on the electrostatic chuck.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0005] A surface morphology smoothing device includes: an electrostatic chuck having a surface to be polished; a temperature control unit disposed opposite to the surface to be polished; and a polishing component having a polishing surface for contacting the surface to be polished of the electrostatic chuck. The temperature control unit is used to heat or cool the polishing component, causing the polishing component to expand when heated or contract when cooled, and the polishing surface of the polishing component polishes the surface to be polished of the electrostatic chuck.

[0006] Optionally, it also includes a driving device for driving the temperature control unit and / or the electrostatic chuck to move. When the temperature control unit heats the polished part, the driving device is used to make the temperature control unit, the polished part and the electrostatic chuck come into contact with each other.

[0007] Optionally, the temperature control unit is provided with a heating device and a first cooling device. The heating device is used to heat the polished part, and the first cooling device is used to cool the polished part. By repeatedly switching the heating device and the first cooling device, the hot-cold cycle is formed.

[0008] Optionally, the polished part further includes a non-polished surface opposite to the polished surface, and the non-polished surface of the polished part is connected to the temperature control unit via thermal grease.

[0009] Optionally, the material of the thermal grease includes: silicone grease or carbon fiber-doped silicone.

[0010] Optionally, the first cooling device includes:

[0011] First cooling chamber;

[0012] A first inlet, communicating with the first cooling chamber; and

[0013] The first outlet is connected to the first cooling chamber;

[0014] When the cooling medium is introduced into the first inlet, the cooling medium flows out sequentially through the first inlet, the first cooling chamber and the first outlet, and carries away some of the heat from the temperature control unit.

[0015] Optionally, it also includes:

[0016] The electrode is disposed within the electrostatic chuck.

[0017] A DC power supply, connected to the electrode, is used to generate electrostatic attraction on the surface of the electrostatic chuck to attract the polished part.

[0018] Optionally, it also includes:

[0019] A second cooling device is disposed inside the electrostatic chuck and is used to cool the electrostatic chuck.

[0020] Optionally, the second cooling device includes:

[0021] Second cooling chamber;

[0022] The second inlet is connected to the second cooling chamber;

[0023] The second outlet is connected to the second cooling chamber;

[0024] When the cooling medium is introduced into the second inlet, the cooling medium flows out sequentially through the second inlet, the second cooling chamber and the second outlet, and carries away some of the heat from the electrostatic clamp.

[0025] Optionally, it further includes: a support platform, the electrostatic chuck is disposed on the support platform, the driving device is used to drive the support platform to move the electrostatic chuck up and down, the polishing part is placed on the electrostatic chuck, and the polishing surface of the polishing part is in contact with the surface to be polished of the electrostatic chuck; the temperature control unit includes a heating device, the heating device is used to heat the temperature control unit; the driving device controls whether the polishing part is in contact with the temperature control unit, thereby controlling whether the polishing part is heated, and the hot and cold cycle is formed by repeatedly switching the polishing part to contact and not contact the temperature control unit.

[0026] Optionally, the temperature control unit includes an infrared radiation source for heating the polished part; by controlling whether the heat from the infrared radiation source reaches the surface of the polished part, the polished part is heated or cooled, and the polished part expands when heated or contracts when cooled to polish the surface of the electrostatic chuck.

[0027] Optionally, it further includes: a partition that can extend into or out of the infrared radiation source and the polished part. When the partition extends into the infrared radiation source and the polished part, the infrared radiation source stops heating the polished part. When the partition extends out of the infrared radiation source and the polished part, the infrared radiation source heats the polished part. By repeatedly switching the partition to extend into or out of the infrared radiation source and the polished part, the hot and cold cycle is formed.

[0028] Optionally, the polished part can be subjected to the thermal-cooling cycle by repeatedly turning the infrared radiation source on and off.

[0029] Optionally, it also includes:

[0030] The processing chamber contains the electrostatic chuck, the heating device, and the polishing component.

[0031] Optionally, it also includes:

[0032] A vacuum pumping device is used to adjust the vacuum level of the processing chamber.

[0033] Optionally, the hardness of the polishing material is greater than or equal to the hardness of the electrostatic chuck material.

[0034] Optionally, the electrostatic chuck is sintered from alumina powder containing doped elements; the doped elements include at least one of magnesium, silicon, or titanium; the material of the polished part includes semiconductor materials or metal materials.

[0035] Optionally, it also includes:

[0036] The first temperature measurement module is used to measure the temperature of the temperature control unit;

[0037] The second temperature measurement module is used to measure the temperature of the electrostatic clamp.

[0038] In other aspects, the present invention also provides a method for improving the surface smoothness of an electrostatic chuck, comprising:

[0039] Provide surface topography smoothing equipment as described above;

[0040] By controlling the temperature control unit to control the polishing part to form a hot and cold cycle, the polishing part expands or contracts to polish the surface to be polished on the electrostatic chuck.

[0041] Optionally, it also includes:

[0042] The temperature of the surface to be polished by the electrostatic chuck is controlled so that the surface to be polished by the electrostatic chuck is always maintained within the set temperature range.

[0043] Optionally, the set temperature range for the surface to be polished by the electrostatic chuck is -10℃ to 80℃.

[0044] Optionally, by controlling the amount of heat reaching the polished part from the temperature control unit or infrared radiation source, the polished part can be made to expand when heated or contract when cooled, specifically including:

[0045] Cooling step: Make it difficult for the heat from the heating device to reach the polished part, and continue for a first set time;

[0046] Heating step: The polished part is heated using the heating device for a second set time;

[0047] The alternating cooling and heating steps are repeated multiple times until the surface morphology of the electrostatic chuck reaches the set requirements.

[0048] The cooling and heating steps form a thermal-cold cycle.

[0049] Optionally, the temperature range of the thermal cooling cycle is -10℃ to 150℃.

[0050] Optionally, the first set time and / or the second set time are between 10s and 30s.

[0051] Optionally, the polishing degree of the electrostatic chuck is characterized by the temperature change curve of the polished part in contact with the electrostatic chuck.

[0052] Optionally, between two adjacent hot and cold cycles, the following is also included:

[0053] Judgment steps: Determine whether the polishing degree of the electrostatic chuck meets the set requirements by measuring the temperature change curve of the polished part in contact with the electrostatic chuck;

[0054] If the polishing degree of the electrostatic chuck does not meet the set requirements, the judgment step described in the previous step is repeated between the next two adjacent hot and cold cycles.

[0055] Optionally, the determination step specifically includes:

[0056] Turn off the heating device and the first cooling device;

[0057] Adjust the relative position of the polishing part and the electrostatic chuck so that the polishing part comes into contact with the surface of the electrostatic chuck to be polished;

[0058] The temperature change curve of the polished part is continuously recorded and compared with the target curve to determine whether the polished part meets the set requirements.

[0059] Compared with the prior art, the present invention has at least the following advantages:

[0060] The present invention creates a hot-cold cycle in the temperature control unit by repeatedly switching between the heating device and the first cooling device, thereby causing the polishing part to expand or contract so that the polishing surface of the polishing part polishes the surface to be polished of the electrostatic chuck, making the surface of the electrostatic chuck smooth, thereby achieving uniform temperature control of the wafer.

[0061] This invention uses an electrostatic chuck to adsorb the workpiece for polishing, which can obtain the maximum pressure of the workpiece on the ceramic layer of the electrostatic chuck. The uniformity of this pressure is better than that of mechanical pressure, making the friction polishing of the ceramic layer of the electrostatic chuck more uniform as the wafer expands or contracts.

[0062] The present invention uses a second cooling device to cool the surface to be polished on the electrostatic chuck, so that the temperature of the surface to be polished on the electrostatic chuck does not change with the temperature of the workpiece, and a controllable temperature difference exists between the workpiece and the electrostatic chuck, which greatly improves the stability of the polishing effect.

[0063] The present invention uses a driving device to make the non-polished surface of the polishing part contact or separate from the temperature control part. When the non-polished surface of the polishing part contacts the temperature control part, it expands due to heat and contracts due to cooling when separated. This allows the polishing surface of the polishing part to polish the surface to be polished on the electrostatic chuck, making the surface of the electrostatic chuck smooth, thereby achieving uniform temperature control of the wafer.

[0064] The infrared radiation source of the present invention is a heating source. The polishing part is heated by the infrared radiation source. The polishing surface of the polishing part expands due to heat. When the partition is moved between the infrared radiation source and the polishing part, the polishing surface of the polishing part cools and contracts, thereby polishing the surface of the electrostatic chuck on the surface to be polished by the polishing surface of the polishing part, making the surface of the electrostatic chuck smooth, thereby achieving uniform temperature control of the wafer. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 This is a schematic diagram of the structure of a JR-type electrostatic chuck according to the present invention;

[0067] Figure 2 for Figure 1Schematic diagram of the structure at point A;

[0068] Figure 3 This is a schematic diagram of the structure of a surface topography smoothing device in an embodiment of the present invention;

[0069] Figure 4 This is a schematic diagram of another surface topography smoothing device in an embodiment of the present invention;

[0070] Figure 5 This is a schematic diagram of another surface topography smoothing device in an embodiment of the present invention;

[0071] Figure 6 This is a schematic diagram of another surface topography smoothing device in an embodiment of the present invention;

[0072] Figure 7 This is a flowchart of a method for improving the surface smoothness of an electrostatic chuck according to an embodiment of the present invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention. To make the objectives, features and advantages of the present invention more apparent and understandable, please refer to the drawings. It should be understood that the structures, proportions, sizes, etc., shown in the accompanying drawings are only used to complement the content disclosed in the specification, for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship or adjustment of the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0074] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0075] The surface smoothing device provided by this invention includes: an electrostatic chuck having a surface to be polished; a temperature control unit disposed opposite to the surface to be polished; and a polishing component having a polishing surface for contacting the surface to be polished on the electrostatic chuck. The temperature control unit is used to heat or cool the polishing component, causing it to expand when heated or contract when cooled, and the polishing surface of the polishing component polishes the surface to be polished on the electrostatic chuck. A detailed description follows:

[0076] Please see Figure 3 This invention provides a surface smoothing device, comprising: an electrostatic chuck, a temperature control unit 2, a heating device 22 and a first cooling device 23 within the temperature control unit 2, and a polishing component 4. The polishing component 4 further includes a polished surface 42 and a non-polished surface 41. The electrostatic chuck includes a surface to be polished; the temperature control unit 2 is disposed opposite to the electrostatic chuck; the heating device 22 is used to heat the temperature control unit 2; the polishing component 4 has a polished surface and a non-polished surface, the non-polished surface being fixed to the temperature control unit 2, and the polished surface being used to contact the surface to be polished on the electrostatic chuck; the first cooling device 23 is used to cool the temperature control unit 2.

[0077] The temperature control unit 2 is heated by the heating device 22 and cooled by the first cooling device 23. The temperature control unit 2 or the electrostatic chuck is moved until the polishing part 4 comes into contact with the electrostatic chuck. By repeatedly switching between the heating device 22 and the first cooling device 23, a hot-cold cycle is formed. The polishing part 4 expands when heated or contracts when cooled, and the polishing surface 42 of the polishing part 4 polishes the surface to be polished by the electrostatic chuck.

[0078] It should be noted that the polished part 4 expands due to heat by contacting the temperature control part 2. Compared with other non-contact heating methods, the heating method in this embodiment of the invention is more stable, with less heat loss and higher heat transfer efficiency.

[0079] In this embodiment, the specific type of electrostatic chuck is not specifically limited; only the JR type electrostatic chuck is used as an example for illustration.

[0080] Please see Figure 1 and Figure 2 The JR type electrostatic chuck includes a base 8 and a ceramic layer 1 located above the base 8. The ceramic layer 1 is doped with elements such as Mg, Si and Ti, which inevitably causes unevenness in the surface state of the JR type electrostatic chuck.

[0081] The base 8 is an aluminum substrate, and the ceramic layer 1 is an Al2O3 ceramic layer. After sintering, the surface of the ceramic layer 1 has several protrusions 111 (see...). Figure 2 Furthermore, the surface of the boss 111 has uneven burrs, and the burr-covered surfaces of several bosses 111 form the polishing surface of the electrostatic chuck. During plasma etching, the uneven burrs on the surface of the bosses 111 affect the temperature uniformity of the wafers adsorbed on the surface of the JR-type electrostatic chuck, directly impacting the uniformity of the etching results. Therefore, the polishing surface of the electrostatic chuck needs to be polished.

[0082] In this embodiment, the electrostatic clamp is disposed opposite to the temperature control unit 2. For example, the electrostatic clamp is disposed on the lower side of the temperature control unit 2 (e.g., Figure 1 (As shown), or the electrostatic clamp is disposed on the upper side of the temperature control unit 2. The electrostatic clamp and the temperature control unit 2 may also have other positional relationships, which are not specifically limited in this embodiment.

[0083] In this embodiment, the temperature control unit 2 includes a temperature control body 21. The shape of the temperature control body 21 is not specifically limited; this embodiment only uses the shape of the body as an example. Figure 3 The specific structure shown is illustrated with examples.

[0084] In this embodiment, the structure of the heating device 22 and the positional relationship between the heating device 22 and the temperature control body 21 are not specifically limited. The heating device 22 is simply described as an electrically controlled heating element built into the temperature control body 21.

[0085] In this embodiment, the non-polished surface 41 of the polished part 4 is directly or through the thermal grease 3 connected to the temperature control part 2. The material of the thermal grease 3 includes: silicone grease or carbon fiber-doped silicone, wherein the silicone grease may also be doped with carbon or aluminum. In this embodiment of the invention, the thermal grease 3 between the polished part 4 and the temperature control part 2 has at least the following functions: 1. To ensure that the polished part 4 is stably fixed on the temperature control part 2 during installation; 2. To act as a buffer between the polished part 4 and the temperature control part 2, ensuring that when the electrostatic chuck is energized and the polished part 4 is adsorbed onto its surface, the temperature control part 2 and the polished part 4 still have good thermal contact, so as to ensure that the temperature control part 2 can always effectively control the temperature of the polished part 4; 3. To ensure that the temperature control part 2 still has good thermal contact with the polished part 4 when the relative displacement between the temperature control part 2 and the polished part 4 occurs due to the difference in the coefficients of thermal expansion between the temperature control part 2 and the polished part 4 during temperature changes.

[0086] In this embodiment, the temperature control unit 2 can form a hot-cold cycle by repeatedly switching the heating device 22 and the first cooling device 23. This causes the polishing part 4, which is in contact with the temperature control unit 2, to expand when heated or contract when cooled, resulting in a relative displacement between it and the surface to be polished on the electrostatic chuck. This allows the polishing surface of the polishing part 4 to polish the surface to be polished on the electrostatic chuck. By coordinating the temperature control with electric heating and the cooling medium, the polishing part 4 can achieve a temperature change of over 40°C within 10 seconds, greatly improving the polishing efficiency.

[0087] In this embodiment, the structure of the first cooling device 23 and the positional relationship between the first cooling device 23 and the temperature control unit 2 are not specifically limited, but only based on... Figure 3The structure and positional relationships shown are illustrated below. Specifically, the first cooling device 23 includes a first cooling chamber 232, a first inlet 231, and a first outlet 233 disposed on the temperature control body 21. Both the first inlet 231 and the first outlet 233 are connected to the first cooling chamber 232. When the cooling medium is introduced into the first inlet 231, the cooling medium flows out sequentially through the first inlet 231, the first cooling chamber 232, and the first outlet 233, carrying away some of the heat from the temperature control body 21, thus cooling the temperature control body 21 and consequently cooling the polished part, causing the polished part to shrink.

[0088] The shape of the first cooling chamber 232 and the specific type of cooling medium are not specifically limited, as long as the cooling medium can uniformly remove the heat from the temperature control unit 2 after passing through the first cooling chamber 232. For example, the cooling medium can be any one or a combination of liquid, gas, and gas-liquid mixture.

[0089] In this embodiment, the surface morphology smoothing device further includes: a first temperature measuring module, which is used to measure the temperature of the temperature control unit 2. The first temperature measuring module, in combination with the heating device 22 and the first cooling device 23, can achieve precise switching of the temperature of the temperature control unit 2, so that the temperature of the polishing part 4 changes periodically, thereby causing the polishing part 4 to expand or contract periodically, and generate a periodic relative displacement between it and the surface to be polished of the electrostatic chuck, and use the polishing surface 42 to polish the surface to be polished of the electrostatic chuck.

[0090] Specifically, the first temperature measurement module can be a temperature sensor array arranged on the polished part 4. The temperature sensor array can be a wireless transmission array integrated on the polished part 4, or a wired sensor array that is processed later and attached to the surface of the polished part 4. Furthermore, the first temperature measurement module can also be a single temperature sensor arranged on the polished part 4. Compared with the expensive temperature sensor array, using a single temperature sensor is more cost-effective.

[0091] In this embodiment, when the polishing surface 42 of the polishing component 4 polishes the surface to be polished of the electrostatic chuck, the polishing surface 42 of the polishing component 4 comes into contact with the surface to be polished of the electrostatic chuck, and the polishing component 4 is subjected to a force in the direction from the polishing component 4 to the electrostatic chuck. The force in the direction from the polishing component 4 to the electrostatic chuck can ensure that the relative position of the polishing component 4 and the electrostatic chuck is fixed, thereby improving the polishing effect of the polishing surface 42 of the polishing component 4 on the surface to be polished of the electrostatic chuck.

[0092] Specifically, the force acting on the polished part 4, directed from the polished part 4 to the electrostatic chuck, can be generated in various ways. For example, an electrode 14 can be installed inside the electrostatic chuck. When the electrode 14 is connected to a DC power supply, it generates an electrostatic attraction, thereby achieving the adsorption and fixation of the polished part 4 by the electrostatic chuck, ensuring close contact between the polished surface 42 of the polished part 4 and the surface to be polished on the electrostatic chuck. Alternatively, when the electrostatic chuck is located below the temperature control unit 2, the weight of the temperature control unit 2 can press the polished part 4 between the electrostatic chuck and the temperature control unit 2, ensuring close contact between the polished surface 42 of the polished part 4 and the surface to be polished on the electrostatic chuck. Alternatively, when the electrostatic chuck is located above the temperature control unit 2, the weight of the electrostatic chuck can press the polished part 4 between the electrostatic chuck and the temperature control unit 2, ensuring close contact between the polished surface 42 of the polished part 4 and the surface to be polished on the electrostatic chuck. Alternatively, the driving device 6 (with a bellows sleeve) can be used to act on the electrostatic chuck and / or the temperature control unit 2, so that the electrostatic chuck and the temperature control unit 2 tightly clamp the polishing workpiece 4, making the polishing surface 42 of the polishing workpiece 4 in close contact with the surface to be polished on the electrostatic chuck. The force on the polishing workpiece 4 in the direction from the polishing workpiece 4 to the electrostatic chuck can also be generated in other ways, which are not specifically limited here.

[0093] The temperature control unit 2 is grounded, and an electrode is provided inside the electrostatic chuck to adsorb the polishing part 4. This allows the polishing part 4 to exert maximum pressure on the ceramic layer 11 of the electrostatic chuck. The uniformity of this pressure is better than that of mechanical pressure, making the frictional polishing of the ceramic layer 11 of the electrostatic chuck by the polishing part 4 more uniform when it expands or contracts.

[0094] In this embodiment, the driving device 6 can be any existing structure, as long as it can directly or indirectly drive the temperature control unit 2 and / or the base 8 to move, so that the polishing part contacts or separates from the surface to be polished of the electrostatic chuck. Further details are omitted here.

[0095] In this embodiment, the surface topography smoothing device further includes a second cooling device 13, formed inside the electrostatic chuck. The second cooling device 13 is used to stabilize the temperature of the electrostatic chuck at a set temperature or within a set temperature range after its activation. The set temperature and set temperature range are not specifically limited; the set temperature / set temperature range can be the initial set temperature / initial set temperature range of the electrostatic chuck before polishing, or other feasible set temperatures / set temperature ranges, as long as it ensures that when the temperature control unit 2 forms a hot-cold cycle, the polishing surface 42 of the polishing workpiece 4 and the surface to be polished of the electrostatic chuck can undergo relative displacement due to the thermal expansion and contraction of the polishing workpiece 4.

[0096] In this embodiment, the structure of the second cooling device 13 and the positional relationship between the second cooling device 13 and the electrostatic chuck are not specifically limited, but only based on... Figure 3The structure and positional relationships shown are illustrated by example. Specifically, the second cooling device 13 is formed inside the electrostatic clamp; the second cooling device 13 includes a second cooling chamber 132, a second inlet 131, and a second outlet 133, both of which are connected to the second cooling chamber 132. When the cooling medium is introduced into the second inlet 131, the cooling medium flows out sequentially through the second inlet 131, the second cooling chamber 132, and the second outlet 133, carrying away some of the heat from the electrostatic clamp.

[0097] In this embodiment, the shape of the second cooling chamber 132 and the specific type of cooling medium are not specifically limited, as long as the cooling medium can uniformly remove the heat from the electrostatic clamp after passing through the second cooling chamber 132. For example, the cooling medium can be any of liquid, gas, and gas-liquid mixture.

[0098] In this embodiment, the surface smoothing device further includes a second temperature measuring module, which measures the temperature of the surface to be polished on the electrostatic chuck. The second temperature measuring module, in conjunction with the second cooling device 13, enables precise temperature control of the surface to be polished on the electrostatic chuck.

[0099] The second temperature measurement module can be a temperature sensor array arranged on the electrostatic clamp. This array can be a wireless transmission array integrated onto the electrostatic clamp, or a wired sensor array that is processed and attached to the surface of the electrostatic clamp later. Alternatively, the second temperature measurement module can be a single temperature sensor arranged on the electrostatic clamp; using a single temperature sensor is more cost-effective than using an expensive temperature sensor array.

[0100] During the polishing process of the surface to be polished by the electrostatic chuck, the surface to be polished by the second temperature measuring module and the second cooling device 13 is controlled at a set temperature or within a set temperature range to prevent the electrostatic chuck from changing temperature due to temperature changes in the temperature control unit 2, which would cause the electrostatic chuck to expand or contract and affect the polishing effect of the electrostatic chuck.

[0101] Figure 3 In this embodiment, the surface topography smoothing device does not include a processing chamber. Figure 4 In this embodiment, the surface topography smoothing device includes a processing chamber 5.

[0102] Figure 5 This is a schematic diagram of another surface topography smoothing device in an embodiment of the present invention.

[0103] Please see Figure 5The electrostatic chuck is placed on the bearing surface of the bearing platform 28; the drive device 7 is installed on the bearing platform 28. The drive device 7 can be any existing structure, which will not be described in detail here; the position of the temperature control unit 2 relative to the processing chamber 5 can be fixed, which can be achieved by integrally molding it with the processing chamber 5.

[0104] The electrostatic chuck includes a base 8 and a ceramic layer 1 located above the base 8. When the surface of the ceramic layer 1 is polished using the polishing surface 42 of the polishing component 4, the heating device 22 is activated to heat the temperature control unit 2 to the set temperature. The driving device 7 is then activated to move the polishing component 4 until its non-polished surface 41 contacts the temperature control unit 2. The polishing surface 42 of the polishing component 4 polishes the electrostatic chuck during the process of thermal expansion. The driving device 7 is activated again to move the support platform 28 until the non-polished surface 41 of the polishing component 4 separates from the temperature control unit 2. The polishing is then cooled by the second cooling device inside the base. Figure 5 (Not shown in the image) The temperature of the electrostatic chuck is reduced, which in turn reduces the temperature of the polished part 4. The polished surface 42 of the polished part 4 polishes the electrostatic chuck again during the expansion and contraction process. The above steps are repeated until the surface morphology flatness of the electrostatic chuck meets the set requirements.

[0105] In this embodiment, the surface morphology smoothing device further includes: a processing chamber 5, wherein the electrostatic chuck is located inside the processing chamber 5, and the temperature control unit 2 is disposed opposite to the electrostatic chuck; an air inlet device 52 for supplying gas into the processing chamber 5; and a vacuum pump for creating a vacuum environment inside the processing chamber 5.

[0106] The air intake device 52 is used to supply gas into the processing chamber 5. The gas includes at least one of nitrogen or air. Electrodes are provided in the electrostatic chuck, and the electrodes are connected to a DC power supply. When the gas is supplied to the surface of the polishing workpiece 4, it can carry away the induced charge, thereby allowing the polishing workpiece 4 to be electrostatically attracted, which is beneficial for the polishing workpiece 4 to polish the electrostatic chuck.

[0107] Figure 6 This is a schematic diagram of another surface topography smoothing device in an embodiment of the present invention.

[0108] Please see Figure 6 In this embodiment, the temperature control unit 9 uses an infrared radiation source 91 to heat the polished part 4, and a movable partition 92 is added between the polished part 4 and the infrared radiation source 91. This partition 92 not only isolates the infrared radiation between the polished part 4 and the infrared radiation source 91, but it can also be grounded to ensure that the electrostatic chuck can adsorb and fix the polished part 4 after its electrodes are connected to a DC power supply. The electrostatic chuck includes a base 8 and a ceramic layer 1 located above the base 8, and the electrostatic chuck is supported on the support platform 28.

[0109] When the partition 92 moves between the polished part 4 and the infrared radiation source 91, the partition 92 isolates the infrared radiation between the polished part 4 and the infrared radiation source 91. At this time, the polished part is not heated by the infrared radiation source 91. A second cooling device 13 is provided inside the electrostatic chuck to reduce the temperature of the electrostatic chuck, thereby reducing the temperature of the polished part 4. When the partition 92 is removed and is no longer positioned between the polished part 4 and the infrared radiation source 91, the infrared radiation from the infrared radiation source 91 can reach the surface of the polished part to heat it, causing the polished part to expand due to heat. The polished part continuously switches between expansion and contraction states, thereby achieving polishing of the surface of the electrostatic chuck.

[0110] In one embodiment, the surface topography smoothing device includes: a processing chamber 5, wherein the electrostatic chuck is located inside the processing chamber 5, and the temperature control unit 2 is disposed opposite to the electrostatic chuck; an air inlet device 52 for supplying gas into the processing chamber 5; and a vacuum pump for creating a vacuum environment inside the processing chamber 5.

[0111] The air intake device 52 is used to supply gas into the processing chamber 5. The gas includes at least one of nitrogen or air. Electrodes are provided in the electrostatic chuck, and the electrodes are connected to a DC power supply. When the gas is supplied to the surface of the polishing workpiece 4, it can carry away the induced charge, thereby allowing the polishing workpiece 4 to be electrostatically attracted, which is beneficial for the polishing workpiece 4 to polish the electrostatic chuck.

[0112] In another embodiment, the surface morphology smoothing device does not include: a processing chamber 5, the partition 92 being grounded, an electrode being disposed inside the electrostatic chuck, the electrode being connected to a DC power supply, which causes the polishing part to be attracted, which is beneficial for the polishing part to polish the surface of the electrostatic chuck.

[0113] In another embodiment, the surface topography smoothing device does not include a partition, and the hot and cold cycle is formed on the polishing part by repeatedly turning the infrared radiation source on and off to polish the surface of the electrostatic chuck.

[0114] The aforementioned processing chamber 5 is enclosed by multiple walls (such as side walls, top walls, and bottom walls). This processing chamber 5 is typically cylindrical, and its side walls can be perpendicular to the top and bottom walls. The electrostatic chuck, the temperature control unit 2, and the polishing component 4 are located within the processing chamber 5. The processing chamber 5 provides a relatively enclosed environment for the electrostatic chuck, temperature control unit 2, and polishing component 4. The surface morphology smoothing device within the processing chamber 5 ensures that the thermal expansion and contraction process of the polishing component 4 is unaffected by the external environment, and also facilitates the inspection and direct control of the internal environment of the processing chamber 5 by personnel. This "internal environment" is a collective concept, encompassing various specific internal environmental factors, such as vacuum level, temperature, light intensity, and air composition.

[0115] In addition, the surface morphology smoothing equipment also includes a vacuum device 51, which is used to adjust the vacuum level inside the processing chamber 5. When using the surface morphology smoothing equipment in this embodiment, the vacuum device 51 is used to evacuate the interior of the processing chamber 5 to a vacuum level, at least meeting the requirements of a rough vacuum. Its functions include at least the following: 1. Removing excess gas from the processing chamber 5; 2. Removing excess moisture from the processing chamber 5; 3. Insulation to ensure the safety of the electrode 14 after it is energized. Correspondingly, the thermal grease 3 is a vacuum thermal grease, which ensures good thermal conductivity between the temperature control unit 2 and the polishing part 4 after the processing chamber 5 is evacuated to a vacuum.

[0116] In the above embodiments, the hardness of the polishing component 4 is greater than or equal to the hardness of the ceramic layer 11 of the electrostatic chuck, thereby ensuring that the polishing surface 42 of the polishing component 4 can effectively polish the surface to be polished of the electrostatic chuck. Specifically, the electrostatic chuck is sintered from alumina powder containing doped elements, wherein the doped elements include at least one of magnesium, silicon, or titanium; the material of the polishing component 4 includes semiconductor materials or metallic materials.

[0117] This embodiment also provides a method for improving the surface smoothness of the electrostatic chuck. Please refer to [link / reference]. Figure 7 The method includes:

[0118] Step S1: Provide the surface topography smoothing equipment as described above;

[0119] Step S2: By controlling the temperature control unit, the polishing part is controlled to form a hot and cold cycle, causing the polishing part to expand or contract, so as to polish the surface to be polished on the electrostatic chuck.

[0120] The thermal-cold cycle on the polished part in this embodiment can be formed in various ways, and the following three methods are specifically illustrated:

[0121] (1) Please refer to Figure 3 or Figure 4 The heating device 22 and the first cooling device 23 are repeatedly switched to form a hot and cold cycle, causing the polishing part 4 to expand or contract periodically, and to generate a periodic relative displacement between it and the surface to be polished of the electrostatic chuck, so as to polish the surface to be polished of the electrostatic chuck using the polishing surface 42.

[0122] (2) Please refer to Figure 5The temperature of the temperature control unit 2 remains constant. The drive device 7 drives the support platform 28 to bring the non-polished surface of the polishing part 4 into contact with the temperature control unit 2. At this time, the polishing part 4 expands due to heat. Then, the drive device 7 drives the support platform 28 to separate the non-polished surface of the polishing part 4 from the temperature control unit 2. The air intake device 52 is opened, and the polishing part 4 cools and contracts. The above steps are repeated to make the polishing part 4 expand or contract periodically, and generate a periodic relative displacement between it and the surface to be polished of the electrostatic chuck. The polishing surface 42 is used to polish the surface to be polished of the electrostatic chuck.

[0123] (3) Please refer to Figure 6 The infrared radiation source heats the polishing part 4, causing it to expand. Then, the partition 92 is moved between the infrared radiation source and the polishing part 4, and the air intake device 52 is opened, causing the polishing part 4 to contract. The above steps are repeated to make the polishing part 4 expand or contract periodically, and to generate a periodic relative displacement between it and the surface to be polished on the electrostatic chuck. The polishing surface 42 is used to polish the surface to be polished on the electrostatic chuck.

[0124] Specifically, the heating device 22 and the first cooling device 23 can be switched manually or electrically, without being specifically limited here.

[0125] In this embodiment, the method further includes:

[0126] Step S3: Control the temperature of the surface to be polished by the electrostatic chuck so that the surface to be polished by the electrostatic chuck is always kept within the set temperature range, and avoid the temperature of the electrostatic chuck changing to the same temperature as the polishing part 4 after the electrostatic chuck comes into contact with the polishing part 4.

[0127] Specifically, the cooling medium is introduced through the second inlet 131, and flows out sequentially through the second inlet 131, the second cooling chamber 132 and the second outlet 133, carrying away some of the heat from the electrostatic chuck. In conjunction with the second cooling device 13, precise temperature control of the surface to be polished on the electrostatic chuck is achieved.

[0128] Specifically, the set temperature range for the surface to be polished by the electrostatic chuck is -10℃ to 80℃.

[0129] In this embodiment, the temperature of the temperature control unit 2 is adjusted by controlling the heating device 22 and the first cooling device 23, thereby causing a change in the temperature of the polished part 4. Specifically, this includes:

[0130] Cooling step: Control the first cooling device 23 to continue for a first set time;

[0131] Heating step: Control the heating device 22 to continue for a second set time;

[0132] The alternating cooling and heating steps are repeated multiple times until the surface morphology of the electrostatic chuck reaches the set requirements.

[0133] The cooling and heating steps form a thermal-cold cycle.

[0134] Specifically, the temperature range of the thermal cooling cycle is -10℃ to 150℃.

[0135] Specifically, the first set time and / or the second set time are between 10s and 30s.

[0136] In this embodiment, the polishing degree of the electrostatic chuck is characterized by the temperature change curve of the polishing part 4 in contact with the electrostatic chuck.

[0137] In this embodiment, between two adjacent hot and cold cycles, the following is also included:

[0138] Step S201: Determine whether the polishing degree of the electrostatic chuck meets the set requirements by measuring the temperature change curve of the polished part 4 in contact with the electrostatic chuck.

[0139] If the polishing degree of the electrostatic chuck does not meet the set requirements, step S201 is repeated between the next two adjacent hot and cold cycles.

[0140] In this embodiment, step S201 specifically includes:

[0141] Turn off the heating device 22 and the first cooling device 23;

[0142] Adjust the relative position of the polishing part 4 and the electrostatic chuck so that the polishing part 4 comes into contact with the surface of the electrostatic chuck to be polished;

[0143] The temperature change curve of the polished part 4 is continuously recorded and compared with the target curve to determine whether the polished part 4 meets the set requirements.

[0144] In summary, the present invention has the following advantages:

[0145] In this embodiment, the temperature control unit 2 forms a hot-cold cycle by repeatedly switching the heating device 22 and the first cooling device 23, thereby causing the polishing part 4, which is in contact with the temperature control unit 2 through the vacuum thermal conductive adhesive, to expand or contract, so that the polishing surface 42 of the polishing part 4 polishes the surface to be polished of the electrostatic chuck.

[0146] In this embodiment, the polishing part 4 is adsorbed by an electrostatic chuck, which can obtain the maximum pressure of the polishing part 4 on the ceramic layer of the electrostatic chuck. The uniformity of this pressure is better than that of mechanical pressure, so that the friction polishing of the ceramic layer of the electrostatic chuck by the expanding or contracting wafer is more uniform.

[0147] In this embodiment, the surface to be polished on the electrostatic chuck is cooled by the second cooling device 13, so that the temperature of the surface to be polished on the electrostatic chuck does not change with the temperature of the polishing part 4, and a controllable temperature difference exists between the polishing part 4 and the electrostatic chuck, which greatly improves the stability of the polishing effect.

[0148] 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 limiting the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A surface morphology smoothing device, characterized in that, include: An electrostatic chuck with a surface to be polished; The temperature control unit is positioned opposite to the surface to be polished; A polishing part having a polishing surface for contacting the surface to be polished by the electrostatic chuck; The temperature control unit is used to heat or cool the polished part. The temperature control unit is provided with a heating device and a first cooling device. The heating device is used to heat the polished part, and the first cooling device is used to cool the polished part. By repeatedly switching the heating device and the first cooling device, a hot and cold cycle is formed for the polished part, so that the polished part expands when heated or contracts when cooled. The polishing surface of the polished part polishes the surface to be polished of the electrostatic chuck.

2. The surface morphology smoothing equipment as described in claim 1, characterized in that, It also includes a driving device for driving the temperature control unit and / or the electrostatic chuck to move. When the temperature control unit heats the polished part, the driving device is used to make the temperature control unit, the polished part and the electrostatic chuck come into contact with each other.

3. The surface morphology smoothing equipment as described in claim 2, characterized in that, The polished part also includes a non-polished surface opposite to the polished surface, and the non-polished surface of the polished part is connected to the temperature control unit through thermal grease.

4. The surface morphology smoothing equipment as described in claim 3, characterized in that, The thermal grease is made of materials including silicone grease or carbon fiber-doped silicone.

5. The surface morphology smoothing equipment as described in claim 2, characterized in that, The first cooling device includes: First cooling chamber; A first inlet, communicating with the first cooling chamber; and The first outlet is connected to the first cooling chamber; When the cooling medium is introduced into the first inlet, the cooling medium flows out sequentially through the first inlet, the first cooling chamber and the first outlet, and carries away some of the heat from the temperature control unit.

6. The surface morphology smoothing equipment as described in claim 1, characterized in that, Also includes: The electrode is disposed within the electrostatic chuck. A DC power supply, connected to the electrode, is used to generate electrostatic attraction on the surface of the electrostatic chuck to attract the polished part.

7. The surface morphology smoothing equipment as described in claim 1, characterized in that, Also includes: A second cooling device is disposed inside the electrostatic chuck and is used to cool the electrostatic chuck.

8. The surface morphology smoothing equipment as described in claim 7, characterized in that, The second cooling device includes: Second cooling chamber; The second inlet is connected to the second cooling chamber; The second outlet is connected to the second cooling chamber; When the cooling medium is introduced into the second inlet, the cooling medium flows out sequentially through the second inlet, the second cooling chamber and the second outlet, and carries away some of the heat from the electrostatic clamp.

9. A surface morphology smoothing device, characterized in that, include: An electrostatic chuck with a surface to be polished; The temperature control unit is positioned opposite to the surface to be polished; A polishing part having a polishing surface for contacting the surface to be polished by the electrostatic chuck; A driving device is used to drive the temperature control unit and / or the electrostatic chuck to move. When the temperature control unit heats the polished part, the driving device is used to make the temperature control unit, the polished part and the electrostatic chuck come into contact with each other. A support platform is provided, the electrostatic chuck is disposed on the support platform, the driving device is used to drive the support platform to move the electrostatic chuck up and down, the polishing part is placed on the electrostatic chuck, and the polishing surface of the polishing part is in contact with the surface of the electrostatic chuck to be polished. The temperature control unit is used to heat or cool the polished part; the temperature control unit includes a heating device, which is used to heat the temperature control unit; the polished part is controlled to be heated by controlling whether the polished part is in contact with the temperature control unit by the driving device; by repeatedly switching the polished part to be in contact with the temperature control unit and not in contact, a hot and cold cycle of the polished part is formed, so that the polished part expands when heated or contracts when cooled, and the polishing surface of the polished part polishes the surface to be polished of the electrostatic chuck.

10. A surface morphology smoothing device, characterized in that, include: An electrostatic chuck with a surface to be polished; The temperature control unit is positioned opposite to the surface to be polished; A polishing part having a polishing surface for contacting the surface to be polished by the electrostatic chuck; The temperature control unit includes an infrared radiation source for heating the polished part; By controlling whether the heat from the infrared radiation source reaches the surface of the polished part, the polished part is heated or cooled. By repeatedly controlling whether the heat from the infrared radiation source reaches the surface of the polished part, a hot and cold cycle is formed for the polished part. The polished part expands when heated or contracts when cooled, polishing the surface of the electrostatic chuck.

11. The surface topography smoothing equipment as described in claim 10, characterized in that, Also includes: A partition can extend into or out of the infrared radiation source and the polished part. When the partition extends into the infrared radiation source and the polished part, the infrared radiation source stops heating the polished part. When the partition extends out of the infrared radiation source and the polished part, the infrared radiation source heats the polished part. By repeatedly switching the partition to extend into or out of the infrared radiation source and the polished part, the polished part forms a hot and cold cycle.

12. The surface morphology smoothing equipment as described in claim 10, characterized in that, By repeatedly turning the infrared radiation source on and off, the polished part is subjected to a hot-cold cycle.

13. The surface topography smoothing equipment according to any one of claims 1-12, characterized in that, Also includes: The processing chamber contains the electrostatic chuck and the polishing component.

14. The surface topography smoothing equipment as described in claim 13, characterized in that, Also includes: A vacuum pumping device is used to adjust the vacuum level of the processing chamber.

15. The surface topography smoothing equipment according to any one of claims 1-12, characterized in that, The hardness of the polishing material is greater than or equal to the hardness of the electrostatic chuck material.

16. The surface topography smoothing equipment as described in claim 15, characterized in that, The electrostatic chuck is formed by sintering alumina powder containing doped elements. The doping element includes at least one of magnesium, silicon, or titanium; the material of the polished part includes a semiconductor material or a metal material.

17. The surface topography smoothing equipment as described in any one of claims 1-12, characterized in that, Also includes: The first temperature measurement module is used to measure the temperature of the temperature control unit; The second temperature measurement module is used to measure the temperature of the electrostatic clamp.

18. A method for improving the surface smoothness of an electrostatic chuck, characterized in that, include: Provide a surface topography smoothing apparatus as described in any one of claims 1 to 17; The temperature control unit controls the polishing part to form a hot and cold cycle, causing the polishing part to expand or contract, so as to polish the surface to be polished by the electrostatic chuck.

19. The method for improving the surface smoothness of an electrostatic chuck as described in claim 18, characterized in that, Also includes: The temperature of the surface to be polished by the electrostatic chuck is controlled so that the surface to be polished by the electrostatic chuck is always maintained within the set temperature range.

20. The method for improving the surface smoothness of an electrostatic chuck as described in claim 19, characterized in that, The set temperature range for the surface to be polished by the electrostatic chuck is -10℃ to 80℃.

21. The method for improving the surface smoothness of an electrostatic chuck as described in claim 18, characterized in that, The polishing degree of the electrostatic chuck is characterized by the temperature change curve of the polished part in contact with the electrostatic chuck.

22. The method for improving the surface smoothness of an electrostatic chuck as described in claim 21, characterized in that, Between two adjacent hot and cold cycles, it also includes: Judgment steps: Determine whether the polishing degree of the electrostatic chuck meets the set requirements by measuring the temperature change curve of the polished part in contact with the electrostatic chuck; If the polishing degree of the electrostatic chuck does not meet the set requirements, the judgment step is repeated between the next two adjacent hot and cold cycles.

23. A method for improving the surface smoothness of an electrostatic chuck, characterized in that, include: A surface morphology smoothing device as described in claim 9 is provided; the temperature control unit controls the polishing part to form a hot and cold cycle, causing the polishing part to expand or contract, so as to polish the surface to be polished by the electrostatic chuck; By controlling the amount of heat reaching the polished part from the temperature control unit, the polished part is made to expand when heated or contract when cooled, specifically including: Cooling step: The heat from the heating device installed in the temperature control unit is difficult to reach the polished part, and this is continued for a first set time; Heating step: The polished part is heated using the heating device for a second set time; The alternating cooling and heating steps are repeated multiple times until the surface morphology of the electrostatic chuck reaches the set requirements. The cooling and heating steps form a thermal-cold cycle.

24. The method for improving the surface smoothness of an electrostatic chuck as described in claim 23, characterized in that, The temperature range of the thermal cooling cycle is -10℃ to 150℃.

25. The method for improving the surface smoothness of an electrostatic chuck as described in claim 23, characterized in that, The first set time and / or the second set time are between 10s and 30s.

26. A method for improving the surface smoothness of an electrostatic chuck, characterized in that, include: A surface morphology smoothing apparatus as described in any one of claims 1 to 8 is provided; the temperature control unit controls the polishing part to form a hot and cold cycle, causing the polishing part to expand or contract, so as to polish the surface to be polished by the electrostatic chuck; the polishing degree of the electrostatic chuck is characterized by the temperature change curve of the polishing part in contact with the electrostatic chuck; Between two adjacent hot and cold cycles, the process further includes: a judgment step: determining whether the polishing degree of the electrostatic chuck meets the set requirements by analyzing the temperature change curve of the polished part in contact with the electrostatic chuck; if the polishing degree of the electrostatic chuck does not meet the set requirements, the judgment step is repeated between the next two adjacent hot and cold cycles; the judgment step specifically includes: The heating device and the first cooling device installed in the temperature control unit shall be turned off. Adjust the relative position of the polishing part and the electrostatic chuck so that the polishing part comes into contact with the surface of the electrostatic chuck to be polished; The temperature change curve of the polished part is continuously recorded and compared with the target curve to determine whether the polished part meets the set requirements.

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