Ceramic heating plate and processing method thereof

Abstract

The invention provides a ceramic heating plate and a processing method of the ceramic heating plate. The machining method of the ceramic heating plate comprises the steps that the ceramic heating plate formed through normal-temperature isostatic pressing is prepared, the upper surface of the ceramic heating plate is made of aluminum nitride, at least an electrostatic adsorption metal wire mesh electrode is embedded in the ceramic heating plate, the process temperature of normal-temperature isostatic pressing forming is lower than 25 DEG C, and the process air pressure of normal-temperature isostatic pressing forming is lower than 200 Mpa; the process temperature of the high-temperature and high-pressure sintering is higher than 1500 DEG C, the process air pressure of the high-temperature and high-pressure sintering is higher than 100 Mpa, and the high-temperature and high-pressure sintering is used for avoiding the use of a binder or a ceramic layer spraying process, so that the heating temperature is increased, the sparking phenomenon of an equipment corrosive agent under high electrostatic adsorption voltage is avoided, and the service life of the equipment corrosive agent is prolonged. The service life of equipment is prolonged; and the safety performance of the process is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and particularly to a ceramic heating plate, as well as a ceramic heating plate and a processing method thereof. Background Art

[0002] In the fields of semiconductor and thin film deposition, plasma enhanced chemical vapor deposition and plasma enhanced atomic layer deposition technologies impose stringent requirements on the stability of low-temperature processes. As a core component, the low-temperature electrostatic adsorption ceramic disk needs to have both electrostatic adsorption, temperature control and corrosion resistance capabilities to ensure the precise fixation and thermal management of wafers during the process. In traditional solutions, electrostatic chucks mostly adopt a structure of a metal aluminum or stainless steel substrate combined with a surface ceramic layer (sprayed or bonded).

[0003] In the prior art, the adhesive of the bonded ceramic disk has insufficient heat resistance. When the process temperature exceeds 200 °C, it is prone to softening or decomposition, resulting in the detachment of the ceramic plate, seriously restricting the working temperature range. At the same time, the adhesive lacks tolerance to the highly reactive plasma and fluoride ion corrosion environment in the cavity. After long-term use, the interface deteriorates, affecting the equipment life and process consistency. In addition, although the sprayed ceramic layer avoids the adhesive problem, the porous structure formed by the spraying process is prone to cause local electric field distortion during high-voltage electrostatic adsorption, resulting in discharge and sparking phenomena, causing wafer damage and ablation of the chuck surface, further restricting the process safety. Therefore, although the prior art can achieve basic functions, its material properties and process defects lead to insufficient high-temperature stability, corrosion resistance and arc breakdown resistance, and it is difficult to meet the requirements of high voltage, wide temperature range and long-term reliability in advanced processes.

[0004] In order to overcome the above-mentioned defects existing in the prior art, there is an urgent need in the art for a ceramic heating plate technology to avoid the use of adhesive or sprayed ceramic layer processes, so as to avoid the corrosion of the equipment and the sparking phenomenon under high electrostatic adsorption voltage while increasing the heating temperature, thereby improving the equipment life and process safety performance. Summary of the Invention

[0005] The following presents a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description to follow.

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a ceramic heating plate and a processing method of the ceramic heating plate, which are used to avoid the use of adhesives or spraying ceramic layer processes, so as to improve the heating temperature while avoiding the sparking phenomenon of the equipment corrosive agent under the high electrostatic adsorption voltage, thereby improving the life of the equipment and the safety performance of the process.

[0007] Specifically, the processing method of the ceramic heating plate provided in accordance with the first aspect of the present invention comprises: preparing a room temperature isostatically pressed ceramic heating plate, wherein the upper surface of the ceramic heating plate is made of aluminum nitride, and at least a metal mesh electrode for electrostatic adsorption is embedded in the interior of the ceramic heating plate, and the process temperature of the room temperature isostatically pressed molding is lower than 25°C, and the process gas pressure is lower than 200Mpa; and performing high temperature and high pressure sintering on the ceramic heating plate, wherein the process temperature of the high temperature and high pressure sintering is higher than 1500°C, and the process gas pressure is higher than 100Mpa.

[0008] Furthermore, in some embodiments of the present invention, the process temperature of the room temperature isostatic pressing is 20°C~25°C, the process pressure is 100Mpa~200Mpa, and the process time is 6 hours~18 hours, the process temperature of the high temperature and high pressure sintering is 1500°C~2000°C, the process pressure is 100Mpa~200Mpa, the process time is 36 hours~72 hours, and the temperature change rate is ±2°C / min~5°C / min.

[0009] Furthermore, in some embodiments of the present invention, the step of preparing a room temperature isostatically pressed ceramic heating plate includes: room temperature isostatically pressing a first ceramic powder to form an upper plate body of the ceramic heating plate, wherein the first ceramic powder is aluminum nitride ceramic powder; placing the wire mesh electrode on the lower surface of the upper plate body; and covering the surface of the wire mesh electrode with a second ceramic powder and performing room temperature isostatic pressing on the second ceramic powder to form a middle plate body of the ceramic heating plate.

[0010] Furthermore, in some embodiments of the present invention, after the middle plate body is formed, the step of preparing the ceramic heating plate by room temperature isostatic pressing also includes: machining a plurality of grooves on the lower surface of the middle plate body; placing a heating wire into each of the grooves; and covering the surface of the heating wire with the second ceramic powder and performing room temperature isostatic pressing on the second ceramic powder to form the lower plate body of the ceramic heating plate.

[0011] Further, in some embodiments of the present invention, after forming the lower disk body, the step of preparing the ceramic heating disk for cold isostatic pressing further includes: welding the first end of the first electrode bar to the wire mesh electrode, wherein the second end of the first electrode bar is used to connect to an external radio frequency power supply; and welding the first end of the second electrode bar to the heating wire, wherein the second end of the second electrode bar is used to connect to an external heating power supply.

[0012] Further, in some embodiments of the present invention, after high-temperature and high-pressure sintering of the ceramic heating disk, the processing method further includes the following steps: processing a ring-shaped boss for supporting the back edge of the wafer on the outer edge of the upper surface of the ceramic heating disk; and / or processing a plurality of bumps for supporting the back of the wafer inside the ring-shaped boss.

[0013] Further, in some embodiments of the present invention, the inner ring diameter of the ring-shaped boss is processed to be 300.1 mm to 303.1 mm, the height is 0.5 mm to 2 mm, there is a slope between the upper surface of the ring-shaped boss and the upper surface of the ceramic heating disk, and the angle of the slope is 10° to 90°. And / or the plurality of bumps have a standard height value, the standard height value is 10 μm to 40 μm, and the error between the maximum value and / or minimum value of the height of each bump and the standard height value is ±15%. The surface roughness of the ceramic heating disk is less than or equal to 0.6 μm, and the surface flatness of the ceramic heating disk is less than or equal to 25 μm.

[0014] Further, in some embodiments of the present invention, after high-temperature and high-pressure sintering of the ceramic heating disk, the processing method further includes the following steps: processing a ring-shaped groove on the lower surface of the ceramic heating disk; preparing a ceramic plate provided with a plurality of uniformly distributed through holes and a disk handle provided with an air passage penetrating up and down; sintering the ceramic plate to the position of the ring-shaped groove at high temperature and high pressure to cover the ring-shaped groove and form a cooling air passage inside the ceramic heating disk; and sintering the first end of the disk handle to the ceramic plate at high temperature and high pressure so that the air passage penetrating up and down aligns with some of the through holes of the ceramic plate to connect the cooling air passage.

[0015] Further, in some embodiments of the present invention, the step of preparing the ceramic plate includes: cold isostatically pressing the second ceramic powder and then performing high-temperature sintering to form a ceramic plate blank; processing the outer contour of the ceramic plate blank so that it is sufficient to cover the ring-shaped groove; and processing a plurality of uniformly distributed through holes on the ceramic plate blank.

[0016] Further, in some embodiments of the present invention, the step of preparing the disc handle includes: isostatically pressing the second ceramic powder at room temperature and then performing high-temperature sintering to form a disc handle blank; and machining the disc handle blank to form at least one airway penetrating up and down inside it.

[0017] Further, in some embodiments of the present invention, the process temperature of the high-temperature sintering is 1300°C to 1800°C, the process time is 36 hours to 72 hours, and the temperature change rate is ±2°C / min to 5°C / min.

[0018] In addition, the ceramic heating disc provided in the second aspect of the present invention is formed by processing through the processing method of the ceramic heating disc according to any one of the first aspects of the present invention.

[0019] Further, in some embodiments of the present invention, a cooling airway is provided inside the ceramic heating disc. The cooling airway communicates with the up-and-down penetrating airway of the disc handle of the ceramic heating disc through at least one first through hole located on the lower surface of the ceramic heating disc to obtain cooling gas, and communicates with the outside through at least one second through hole located on the lower surface of the ceramic heating disc to discharge the gas after heat exchange with the ceramic heating disc. Description of the Drawings

[0020] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and components with similar related characteristics or features may have the same or similar reference numerals.

[0021] Figure 1 Shows a schematic structural diagram of a ceramic heating disc provided according to some embodiments of the present invention.

[0022] Figure 2 Shows a schematic flow diagram of a processing method of a ceramic heating disc provided according to some embodiments of the present invention.

[0023] Figure 3A Shows a schematic structural diagram of an upper disc body provided according to some embodiments of the present invention.

[0024] Figure 3B Shows a schematic structural diagram of a middle disc body provided according to some embodiments of the present invention.

[0025] Figure 3C Shows a schematic structural diagram of a groove provided according to some embodiments of the present invention.

[0026] Figure 3D Shows a schematic structural diagram of a heating wire provided according to some embodiments of the present invention.

[0027] Figure 3E Shows a schematic structural diagram of the lower disk body provided according to some embodiments of the present invention.

[0028] Figure 4 Shows a schematic structural diagram of the outer edge of the upper surface of the ceramic heating disk provided according to some embodiments of the present invention.

[0029] Figure 5A Shows a schematic structural diagram of the air duct provided according to some embodiments of the present invention.

[0030] Figure 5B Shows a schematic structural diagram of the co-firing of the lower disk body and the ceramic plate provided according to some embodiments of the present invention.

[0031] Figure 5C Shows a schematic structural diagram of the co-firing of the ceramic plate and the disk handle provided according to some embodiments of the present invention.

[0032] Figure 6A Shows a schematic structural diagram of the ceramic plate provided according to some embodiments of the present invention.

[0033] Figure 6B Shows a schematic structural diagram of the disk handle provided according to some embodiments of the present invention.

[0034] Reference numerals:

[0035] 10 Wafer

[0036] 20 Upper disk body

[0037] 21 Metal wire mesh

[0038] 30 Middle disk body

[0039] 31 Heating wire

[0040] 40 Lower disk body

[0041] 41 Boss

[0042] 42 Bump

[0043] 43 Thimble through-hole

[0044] 50 Cooling air duct

[0045] 51 Ceramic plate

[0046] 60 Disk handle

[0047] 70 First electrode rod

[0048] 71 Second electrode rod

[0049] 80 Cooling gas regulating device Detailed Implementation Modes

[0050] The following specific embodiments illustrate the implementation modes of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in conjunction with preferred embodiments, this does not mean that the features of this invention are limited to this implementation mode. On the contrary, the purpose of introducing the invention in conjunction with the implementation mode is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or obscuring the key points of the present invention, some specific details will be omitted in the description.

[0051] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0052] In addition, the "upper", "lower", "left", "right", "top", "bottom", "horizontal", and "vertical" used in the following description should be understood as the orientations shown in this paragraph and the relevant drawings. This relative term is only for convenience of description and does not mean that the device described needs to be manufactured or operated in a specific orientation, so it should not be understood as a limitation to the present invention.

[0053] It can be understood that although terms such as "first", "second", and "third" can be used here to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first component, region, layer, and / or part discussed below can be referred to as the second component, region, layer, and / or part without departing from some embodiments of the present invention.

[0054] As mentioned above, in the fields of semiconductors and thin film deposition, plasma-enhanced chemical vapor deposition (PECVD) and plasma-enhanced atomic layer deposition (PEALD) technologies pose strict requirements on the stability of low-temperature processes. As the core component, the low-temperature electrostatic adsorption ceramic disk needs to have both electrostatic adsorption, temperature control, and corrosion resistance capabilities to ensure the precise fixation and thermal management of the wafer during the process. In traditional solutions, electrostatic chucks mostly adopt a structure of a metal aluminum or stainless steel substrate combined with a surface ceramic layer (sprayed or bonded).

[0055] In the prior art, the adhesive of the bonded ceramic disc has insufficient heat resistance. When the process temperature exceeds 200°C, it is easy to soften or decompose, causing the ceramic plate to fall off, which seriously limits the operating temperature range. At the same time, the adhesive lacks tolerance to the highly active plasma and fluoride ion corrosion environment in the cavity. After long-term use, the interface deteriorates, affecting the equipment life and process consistency. In addition, although the sprayed ceramic layer avoids the adhesive problem, the porous structure formed by the spraying process is prone to cause local electric field distortion during high-voltage electrostatic adsorption, resulting in discharge sparking, causing wafer damage and suction cup surface ablation, further restricting process safety. Therefore, although the existing technology can achieve basic functions, its material properties and process defects lead to insufficient high-temperature stability, corrosion resistance and arc breakdown resistance, which is difficult to meet the requirements of high voltage, wide temperature range and long-term reliability in advanced processes.

[0056] In order to overcome the above-mentioned defects of the prior art, the present invention provides a ceramic heating plate and a processing method of the ceramic heating plate, which are used to avoid the use of adhesives or spraying ceramic layer processes, so as to improve the heating temperature while avoiding the sparking phenomenon of the equipment corrosive agent under the high electrostatic adsorption voltage, thereby improving the life of the equipment and the safety performance of the process.

[0057] In some non-limiting embodiments, the ceramic heating plate provided in the second aspect of the present invention is formed by the processing method of the ceramic heating plate described in any one of the first aspects of the present invention. The upper surface of the ceramic heating plate is made of aluminum nitride, at least a metal wire mesh electrode for electrostatic adsorption is embedded in the interior of the ceramic heating plate, and the ceramic heating plate is first formed by isostatic pressing at room temperature and then sintered at high temperature and high pressure.

[0058] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a ceramic heating plate provided according to some embodiments of the present invention is shown.

[0059] like Figure 1 As shown, a cooling air duct 50 is provided inside the ceramic heating plate. The cooling air duct 50 is connected to the upper and lower through air ducts of the plate handle 60 of the ceramic heating plate through at least one first through hole located on the lower surface of the ceramic heating plate to obtain cooling gas, and is connected to the outside through at least one second through hole located on the lower surface of the ceramic heating plate to discharge the gas after heat exchange with the ceramic heating plate.

[0060] The following will describe the processing method of the ceramic heating plate in combination with the specific structure of the ceramic heating plate. Those skilled in the art will understand that the embodiments of the processing method of the ceramic heating plate are only some non-limiting implementation methods provided by the present invention, which are intended to clearly demonstrate the main concept of the present invention and provide some specific solutions that are convenient for the public to implement, rather than to limit the execution subject or execution order of each step in the processing method of the ceramic heating plate.

[0061] Please refer to Figure 2 and Figures 3A to 3E , Figure 2 A schematic flow chart of a method for processing a ceramic heating plate according to some embodiments of the present invention is shown. Figure 3A A schematic structural diagram of an upper disk body provided according to some embodiments of the present invention is shown. Figure 3B A schematic structural diagram of a middle disk body provided according to some embodiments of the present invention is shown. Figure 3C A schematic structural diagram of a groove provided according to some embodiments of the present invention is shown. Figure 3D A schematic structural diagram of a heating wire provided according to some embodiments of the present invention is shown. Figure 3E A schematic structural diagram of a lower plate provided according to some embodiments of the present invention is shown.

[0062] like Figure 2 and Figures 3A to 3E As shown, through the processing equipment of the ceramic heating plate, the processing method of the ceramic heating plate can first perform step S1: prepare a ceramic heating plate formed by isostatic pressing at room temperature. Here, the upper surface of the ceramic heating plate is made of aluminum nitride, and at least a metal wire mesh 21 electrode for electrostatic adsorption is embedded in the interior of the ceramic heating plate. The process temperature of the isostatic pressing at room temperature is lower than 25°C, and its process gas pressure is lower than 200Mpa.

[0063] Specifically, the processing method can form the upper plate body 20 of the ceramic heating plate by isostatic pressing of the first ceramic powder at room temperature, wherein the first ceramic powder is aluminum nitride ceramic powder, and the volume resistivity of the first ceramic powder at 200°C is 3E+10Ω·cm, and the volume resistivity at 390°C is 1E+9Ω·cm. Afterwards, a metal wire mesh 21 electrode is placed on the lower surface of the upper plate body 20. Afterwards, the surface of the metal wire mesh 21 electrode is covered with a second ceramic powder, and isostatic pressing is performed at room temperature to form the middle plate body 30 of the ceramic heating plate. Here, the thermal conductivity of the second ceramic powder at 200°C is greater than 100W / (m·K), and the thermal conductivity at 390°C is greater than 75W / (m·K). Finally, a plurality of grooves are processed on the lower surface of the middle plate body 30, a heating wire 31 is placed in each groove, and the surface of the heating wire 31 is covered with the second ceramic powder, and isostatic pressing is performed at room temperature to form the lower plate body 40 of the ceramic heating plate.

[0064] Here, the process temperature for isostatic pressing at room temperature is 20°C to 25°C, the process pressure is 100 Mpa to 200 Mpa, and the process time is 6 hours to 18 hours. The process temperature for high-temperature and high-pressure sintering is 1500°C to 2000°C, the process pressure is 100 Mpa to 200 Mpa, the process time is 36 hours to 72 hours, and the temperature change rate is ±2°C / min to 5°C / min.

[0065] After that, the processing method of the ceramic heating plate can first perform step S2: performing high-temperature and high-pressure sintering on the ceramic heating plate, where the process temperature for high-temperature and high-pressure sintering is higher than 1500°C, and the process air pressure is higher than 100 Mpa.

[0066] Please refer to Figure 4 , Figure 4 which shows a schematic structural diagram of the outer edge of the upper surface of the ceramic heating plate provided according to some embodiments of the present invention.

[0067] As Figure 4 shown, the processing equipment can also perform fine processing on the external dimensions of the ceramic plate. Specifically, on the outer edge of the upper surface of the ceramic heating plate, an annular boss 41 for supporting the back edge of the wafer 10 is processed, and inside the annular boss 41, a plurality of bumps 42 for supporting the back of the wafer 10 are processed.

[0068] In some embodiments, the diameter of the first disk surface is 329.8 mm to 380.2 mm, the thickness of the first disk surface is 13.8 mm to 22.2 mm, and the height is 39.5 mm to 200.5 mm. The inner diameter of the annular boss 41 is processed to be 300.1 mm to 303.1 mm, the height is 0.5 mm to 2 mm, and there is a slope between the upper surface of the annular boss 41 and the upper surface of the ceramic heating plate, and the angle of the slope is 10° to 90°. Here, the setting of the surface parameters of the heating plate can affect the placement position of the wafer 10, thereby effectively improving the uniformity of the air flow and radio frequency field distribution at the edge of the wafer 10.

[0069] In some embodiments, the plurality of bumps 42 have a standard height value, the standard height value is 10 μm to 40 μm, and the error between the maximum value and / or minimum value of the height of each bump 42 and the standard height value is ±15%. The surface roughness of the ceramic heating plate is less than or equal to 0.6 μm, and the surface flatness of the ceramic heating plate is less than or equal to 25 μm. Here, the setting of the surface parameters of the heating plate can effectively improve the electrostatic adsorption force.

[0070] Furthermore, the surface roughness of the upper surface of the boss 41 is less than or equal to 0.4 μm, the inner diameter of the thimble through-hole 43 is 1.95 mm to 6.05 mm, and the inner surface roughness is less than or equal to 1.3 μm.

[0071] Here, the present invention forms a dense and pore-free integrated ceramic disk by abandoning the traditional bonding process and adopting the isostatic pressing at room temperature combined with the high-temperature and high-pressure sintering technology. This design not only extends the working temperature range to 200°C to 390°C, completely eliminating the risks of thermal failure and corrosion failure of the adhesive, but also significantly reduces the electric field concentration effect under high voltage due to the dense and pore-free ceramic layer, thus preventing the phenomenon of discharge and sparking.

[0072] In addition, for the existing low-temperature electrostatic chuck, it will heat the heating disk under radio frequency energy. Even when the power supply for heating the heating disk itself is turned off, the temperature of the heating disk will continue to rise, resulting in out-of-control temperature of the heating disk. Therefore, after the high-temperature and high-pressure sintering of the ceramic heating disk, the processing method can also be configured with a heat dissipation function to enable stable temperature control during the thin film deposition process.

[0073] Please refer to Figures 5A to 5C , Figure 5A which shows a schematic structural diagram of an air passage provided according to some embodiments of the present invention. Figure 5B which shows a schematic structural diagram of co-firing of the lower disk body and the ceramic plate provided according to some embodiments of the present invention. Figure 5C which shows a schematic structural diagram of co-firing of the ceramic plate and the disk handle provided according to some embodiments of the present invention.

[0074] As Figures 5A to 5C shown, first, the processing equipment can process an annular groove on the lower surface of the ceramic heating disk.

[0075] After that, prepare a ceramic plate 51 provided with a plurality of uniformly distributed through holes and a disk handle 60 provided with an air passage penetrating up and down. Sinter the ceramic plate 51 at high temperature and high pressure to the position of the annular groove to cover the annular groove and form a cooling air passage 50 inside the ceramic heating disk. Sinter the first end of the disk handle 60 to the ceramic plate 51 at high temperature and high pressure, and align the air passage penetrating up and down with some through holes of the ceramic plate 51 to connect it with the cooling air passage 50.

[0076] Please refer to Figures 6A to 6B , Figure 6A which shows a schematic structural diagram of the ceramic plate provided according to some embodiments of the present invention. Figure 6B which shows a schematic structural diagram of the disk handle 60 provided according to some embodiments of the present invention.

[0077] As Figures 6A to 6BAs shown, prepare a ceramic plate 51 provided with a plurality of through holes evenly distributed. First, the second ceramic powder needs to be isostatically pressed at room temperature and then sintered at high temperature to form a ceramic plate blank. Then, the outer contour of the ceramic plate blank is processed to make it sufficient to cover the annular groove. Finally, a plurality of through holes evenly distributed are processed on the ceramic plate blank. The process temperature for high-temperature sintering is 1300°C to 1800°C, the process time is 36 hours to 72 hours, and the temperature change rate is ±2°C / min to 5°C / min.

[0078] Correspondingly, in some embodiments, prepare a disc handle 60 provided with an air passage penetrating up and down. First, the second ceramic powder needs to be isostatically pressed at room temperature and then sintered at high temperature to form a blank of the disc handle 60. After that, the blank of the disc handle 60 is machined to form at least one air passage penetrating up and down inside it. The process temperature for high-temperature sintering is 1300°C to 1800°C, the process time is 36 hours to 72 hours, and the temperature change rate is ±2°C / min to 5°C / min.

[0079] Please continue to refer to Figure 1 , the ceramic disc further includes a cooling gas regulating device 80. The gas is introduced from the center of the bottom surface of the ceramic disc body, and the temperature at the center of the disc surface is affected by the gas temperature and flow rate. The temperature distribution on the ceramic disc surface often shows a concentric distribution state, and there is a temperature cold spot at the center of the disc surface. The temperature at the center of the disc surface can be increased by increasing the gas temperature or reducing the flow rate. If there is a temperature hot spot at the center, the temperature at the center of the disc surface can be reduced by correspondingly reducing the gas temperature or increasing the gas flow rate.

[0080] Thus, by integrating a high-precision cooling air passage 50 network at the bottom of the ceramic disc, the heat generated by radio frequency parasitic heating and the process can be exported in real time through an active circulating cooling medium. Even when the power supply of the heating disc is turned off, the temperature of the chuck can still be accurately regulated to avoid thermal runaway.

[0081] Please continue to refer to Figure 1 , the ceramic heating disc formed by isostatic pressing at room temperature may further include a first electrode rod 70 and a second electrode rod 71. Here, the first end of the first electrode rod 70 is welded to the metal mesh 21 electrode, and the second end of the first electrode rod 70 is used to connect to an external radio frequency power supply for exciting an in-situ plasma field. The first end of the second electrode rod 71 is welded to the heating wire 31, and the second end of the second electrode rod 71 is used to connect to an external heating power supply for heating the heating disc.

[0082] In summary, the ceramic heating disc and its processing method provided by the present invention can be used to avoid the use of the binder or the process of spraying a ceramic layer, so as to avoid the phenomenon of arcing under high electrostatic adsorption voltage of equipment corrosion while increasing the heating temperature, thereby improving the service life of the equipment and the safety performance of the process.

[0083] Although the methods described above have been illustrated and described as a series of acts for simplicity of explanation, it should be understood and appreciated that the methods are not limited by the order of the acts, as some acts may occur in different orders and / or concurrently with other acts from those illustrated and described herein or not illustrated and described herein but understood by those skilled in the art, in accordance with one or more embodiments.

[0084] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for processing a ceramic heating plate, characterized in that: include: Prepare a room temperature isostatic pressing ceramic heating plate, wherein the upper surface of the ceramic heating plate is made of aluminum nitride, at least a metal wire mesh electrode for electrostatic adsorption is embedded in the interior of the ceramic heating plate, the process temperature of the room temperature isostatic pressing is lower than 25°C, and the process gas pressure is lower than 200Mpa; and The ceramic heating plate is subjected to high temperature and high pressure sintering, wherein the process temperature of the high temperature and high pressure sintering is higher than 1500° C. and the process gas pressure is higher than 100 MPa.

2. The processing method according to claim 1, characterized in that: The process temperature of the room temperature isostatic pressing is 20°C to 25°C, the process pressure is 100Mpa to 200Mpa, and the process time is 6 hours to 18 hours. The process temperature of the high temperature and high pressure sintering is 1500°C to 2000°C, the process pressure is 100Mpa to 200Mpa, the process time is 36 hours to 72 hours, and the temperature change rate is ±2°C / min to 5°C / min.

3. The processing method according to claim 1, characterized in that: The steps of preparing the ceramic heating plate formed by isostatic pressing at room temperature include: isostatically pressing a first ceramic powder at room temperature to form an upper plate body of the ceramic heating plate, wherein the first ceramic powder is aluminum nitride ceramic powder; Placing the metal mesh electrode on the lower surface of the upper plate; and The surface of the metal wire mesh electrode is covered with second ceramic powder, and isostatic pressing is performed on the second ceramic powder at room temperature to form the middle plate body of the ceramic heating plate.

4. The processing method according to claim 3, characterized in that: After forming the middle plate body, the step of preparing the ceramic heating plate formed by isostatic pressing at room temperature further comprises: A plurality of grooves are machined on the lower surface of the middle plate; placing a heating wire into each of the grooves; and The second ceramic powder is covered on the surface of the heating wire and isostatically pressed at room temperature to form the lower plate body of the ceramic heating plate.

5. The processing method according to claim 4, characterized in that: After forming the lower plate body, the step of preparing the ceramic heating plate formed by isostatic pressing at room temperature further comprises: Welding a first end of a first electrode rod to the metal mesh electrode, wherein a second end of the first electrode rod is used to connect to an external radio frequency power source; and The first end of the second electrode rod is welded to the heating wire, wherein the second end of the second electrode rod is used to connect to an external heating power source.

6. The processing method according to claim 1, characterized in that: After the ceramic heating plate is sintered at high temperature and high pressure, the processing method further comprises the following steps: An annular boss is formed on the outer edge of the upper surface of the ceramic heating plate to support the back edge of the wafer; and / or A plurality of convex points for supporting the back side of the wafer are formed on the inner side of the annular boss.

7. The processing method according to claim 6, characterized in that: The inner ring diameter of the annular boss is processed to be 300.1 mm to 303.1 mm, the height is 0.5 mm to 2 mm, there is a slope between the upper surface of the annular boss and the upper surface of the ceramic heating plate, the angle of the slope is 10° to 90°, and / or The plurality of protrusions have a standard height value, the standard height value is 10 μm to 40 μm, the error between the maximum value and / or the minimum value of each protrusion height and the standard height value is ±15%, the surface roughness of the ceramic heating plate is less than or equal to 0.6 μm, and the surface flatness of the ceramic heating plate is less than or equal to 25 μm.

8. The processing method according to claim 1, characterized in that: After the ceramic heating plate is sintered at high temperature and high pressure, the processing method further comprises the following steps: An annular groove is formed on the lower surface of the ceramic heating plate; Prepare a ceramic plate with a plurality of evenly distributed through holes and a plate handle with upper and lower through-flow passages; Sintering the ceramic plate at high temperature and high pressure to the position of the annular groove to cover the annular groove and form a cooling air passage inside the ceramic heating plate; and The first end of the disk handle is sintered to the ceramic plate at high temperature and high pressure, and the upper and lower through-air passages are aligned with part of the through holes of the ceramic plate to connect with the cooling air passage.

9. The processing method according to claim 8, characterized in that: The steps of preparing the ceramic plate include: isostatically pressing the second ceramic powder at room temperature, and then sintering at high temperature to form a ceramic slab; Processing the outer contour of the ceramic slab to be sufficient to cover the annular groove; as well as A plurality of evenly distributed through holes are formed on the ceramic slab.

10. The processing method according to claim 9, characterized in that: The steps of preparing the disk handle include: isostatically pressing the second ceramic powder at room temperature, and then sintering it at high temperature to form a disk handle blank; and The disk handle blank is machined to form at least one vertical through-flowing air passage inside the disk handle blank.

11. The processing method according to claim 9 or 10, characterized in that: The process temperature of the high-temperature sintering is 1300° C. to 1800° C., the process time is 36 hours to 72 hours, and the temperature change rate is ±2° C. / min to 5° C. / min.

12. A ceramic heating plate, characterized in that: The ceramic heating plate is formed by processing the ceramic heating plate according to any one of claims 1 to 11.

13. The ceramic heating plate according to claim 12, characterized in that: A cooling air duct is provided inside the ceramic heating plate, and the cooling air duct is connected to the upper and lower through air ducts of the plate handle of the ceramic heating plate through at least one first through hole located on the lower surface of the ceramic heating plate to obtain cooling gas, and is connected to the outside through at least one second through hole located on the lower surface of the ceramic heating plate to discharge the gas after heat exchange with the ceramic heating plate.

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