Wafer bearing device with heating function

Abstract

The utility model relates to a wafer bearing device with a heating function. The wafer bearing device comprises a fixing ring, a bearing disc and a heating plate. The fixing ring surrounds the hollow area and is provided with a top and a bottom, and the hollow area is communicated with the top and the bottom. The carrying disc is provided with a carrying surface and a bottom surface, the carrying disc is detachably fixed at the top of the fixing ring, and the bottom surface covers the hollow area; the thermal expansion coefficient of the carrying disc is smaller than that of the fixing ring. The heating plate is arranged in the hollow area and used for heating the bottom face.

Description

Technical Field

[0001] The utility model relates to a wafer carrier, in particular to a wafer carrier device with a heating function. Background Art

[0002] During the processing, the wafer must be firmly fixed on a plane so that various wafer processing processes can be carried out accurately. The aforementioned processing processes include but are not limited to thin film deposition, wafer thinning, exposure, and etching.

[0003] In the prior art, a carrier plate is used to carry the wafer being processed. The carrier plate has a carrying surface for carrying the wafer. The carrying surface is provided with vents. When a vacuum pump is used to apply negative pressure to the vents, the carrier plate can attract the wafer through the negative pressure, so that the wafer is stably fixed on the carrying surface.

[0004] The aforementioned processing usually involves heating the wafer so that the temperature of the wafer meets the necessary temperature conditions. The existing heating technology is to heat the carrier with a heating device, and after the carrier achieves a uniform temperature effect, the wafer is evenly heated.

[0005] The carrier will also expand when heated. If the thermal expansion of the carrier is too large, it will change the contact state between the carrier and the wafer, which will adversely affect the wafer processing technology. For example, the film thickness uniformity (Total Thickness Variation, TTV) is poor or back plating occurs during the ALD process.

[0006] Therefore, in the prior art, the carrier is usually made of a metal with a low thermal expansion coefficient to prevent excessive thermal expansion. A common metal with a low thermal expansion coefficient is titanium alloy. However, titanium alloy has a high material cost and is difficult to process, which often increases the production cost of the carrier. Utility Model Content

[0007] Based on the above technical issues, the utility model proposes a wafer carrier with a heating function, which can effectively avoid wafer processing problems caused by excessive thermal expansion of the carrier, and maintain a low manufacturing cost of the wafer carrier.

[0008] At least one embodiment of the utility model provides a wafer carrier with a heating function, comprising a fixed ring, a carrier and a heating plate. The fixed ring surrounds the hollow area, and the fixed ring has a top and a bottom, wherein the hollow area connects the top and the bottom. The carrier has a bearing surface and a bottom surface, and the carrier is detachably fixed to the top of the fixed ring, and the bottom surface covers the hollow area; wherein the thermal expansion coefficient of the carrier is smaller than the thermal expansion coefficient of the fixed ring. The heating plate is arranged in the hollow area for heating the bottom surface.

[0009] Preferably, the linear thermal expansion coefficient of the thermal expansion coefficient of the carrier is less than 15 x 10-6 / °C.

[0010] Furthermore, the wafer carrier device with heating function also includes a flexible heat-conducting medium, which is clamped between the bottom surface of the carrier and the heating plate.

[0011] Preferably, a shallow groove is provided on the bottom surface of the carrier plate, and the flexible heat-conducting medium is filled in the shallow groove.

[0012] Preferably, the shallow groove is located in the center of the bottom surface.

[0013] Preferably, a gas channel is formed inside the carrier, and the carrier has a gas extraction port. The gas channel is connected to the carrier surface and the gas extraction port, and the gas channel forms a plurality of ventilation openings on the carrier surface.

[0014] Preferably, the carrier plate further comprises a plurality of air guiding grooves, which extend on the carrying surface and at least extend to one ventilation opening.

[0015] Preferably, the air extraction port is located on a side of the carrier plate.

[0016] Furthermore, the wafer carrier with heating function also includes a fixing plate and a fixing member; the fixing plate is used to carry the heating plate, and the fixing member is combined with the edge of the fixing plate to support the heating plate.

[0017] Furthermore, the wafer carrier with heating function also includes an insulating block combined with the fixed bottom, and the fixing member is fixed to the insulating block.

[0018] Through the wafer carrier with heating function proposed by the utility model, the carrier can maintain a low thermal expansion coefficient configuration to avoid adverse effects on the wafer during wafer processing. The wafer carrier is composed of multiple different components, and low-cost materials can be selected for components other than the carrier, thereby reducing the overall manufacturing cost of the wafer carrier with heating function. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a stereogram of an embodiment of the utility model.

[0020] Figure 2 It is a side exploded view of an embodiment of the utility model, with some components presented in cross-section.

[0021] Figure 3 It is a side view of an embodiment of the utility model, with some components shown in cross-section.

[0022] Figure 4 It is a top view of the carrier plate in the embodiment of the utility model.

[0023] Figure 5 It is a side exploded view of another embodiment of the utility model, with some components shown in cross-section.

[0024] Figure 6 It is a bottom view of the carrier plate in the embodiment of the utility model.

[0025] Figure 7 It is a side view of an embodiment of the utility model, with some components shown in cross-section.

[0026] Explanation of the reference numerals: 100 - wafer carrier with heating function; 110 - fixing ring; 110a - hollow area; 112 - top; 114 - bottom; 120 - carrier; 121 - side; 122 - carrying surface; 123 - gas channel; 124 - bottom surface; 124a - shallow groove; 126 - exhaust port; 128 - ventilation opening; 129 - air guide groove; 130 - heating plate; 140 - flexible thermal conductive medium; 150 - fixing plate; 160 - fixing piece; 170 - insulating block. DETAILED DESCRIPTION

[0027] See also Figure 1 , Figure 2 and Figure 3 As shown, a wafer carrier 100 with a heating function disclosed in an embodiment of the present invention is used to be arranged in a wafer processing equipment. The wafer carrier 100 with a heating function can be used to fix a wafer thereon and heat the wafer. The wafer processing equipment includes but is not limited to ALD equipment (Atomic Layer Deposition equipment) and wafer thinning equipment (Wafer Thinning equipment). Figures 1 to 4 As shown, the wafer carrying device 100 with heating function includes a fixing ring 110 , a carrier plate 120 and a heating plate 130 .

[0028] like Figures 1 to 4 As shown, the fixing ring 110 surrounds the hollow area 110a. The fixing ring 110 has a top 112 and a bottom 114. The hollow area 110a communicates the top 112 with the bottom 114.

[0029] like Figures 1 to 3 As shown, the carrier 120 has a carrying surface 122 and a bottom surface 124. The carrying surface 122 is used to carry the wafer thereon. The carrier 120 is detachably fixed to the top 112 of the fixing ring 110, and the bottom surface 124 covers the hollow area 110a. The thermal expansion coefficient of the carrier 120 is smaller than the thermal expansion coefficient of the fixing ring 110. The heating plate 130 is disposed in the hollow area 110a, and is used to heat the bottom surface 124, so that the overall temperature of the carrier 120 rises, thereby heating the wafer.

[0030] like Figures 1 to 4 As shown, in addition to carrying the wafer, the carrier 120 can also fix the wafer on the carrying surface 122. A gas channel 123 is formed inside the carrier 120, and the carrier 120 has an exhaust port 126. The gas channel 123 connects the carrying surface 122 and the exhaust port 126, and the gas channel 123 forms a plurality of ventilation openings 128 on the carrying surface 122. In addition, the carrier 120 also includes a plurality of air guide grooves 129, and the plurality of air guide grooves 129 extend on the carrying surface 122 and extend to at least one ventilation opening 128. The exhaust port 126 is located on the side 121 of the carrier 120. The exhaust port 126 is used to be connected to an exhaust pump. After the exhaust pump is started to exhaust air, negative pressure can be generated through the ventilation openings 128 and the air guide grooves 129 to adsorb and fix the wafer on the carrying surface 122.

[0031] When the heating plate 130 is heated, the fixing ring 110 and the carrier 120 will inevitably expand due to heat, changing the contact state between the carrier 120 and the wafer, thereby causing adverse effects on the wafer processing process, such as poor film thickness uniformity (Total Thickness Variation, TTV) or back plating during the ALD process.

[0032] Therefore, in a specific embodiment, the carrier 120 is made of a material with a low thermal expansion coefficient. An embodiment of the material with a low thermal expansion coefficient is made of titanium metal or titanium alloy, and its linear thermal expansion coefficient is <15x 10-6 / °C. Therefore, when the carrier 120 is heated, the degree of thermal expansion will be reduced as much as possible, thereby avoiding excessive changes in the contact state between the carrier 120 and the wafer, which will have an adverse effect on the wafer processing process. The fixing ring 110 can be made of traditional high-rigidity materials, such as SUS304 or aluminum metal. The fixing ring 110 can be made of materials with lower costs, and only the carrier 120 uses materials with higher costs (such as titanium metal or titanium alloy), which can control the manufacturing cost of the wafer carrier 100 as a whole.

[0033] like Figures 1 to 3 As shown, in addition, the wafer carrier 100 with heating function further includes a fixing plate 150 and a fixing member 160; the fixing plate 150 is used to carry the heating plate 130, and the fixing member 160 is combined with the edge of the fixing plate 150 to support the heating plate 130. In order to further fix the heating plate 130 to the fixing ring 110, the wafer carrier 100 with heating function further includes an insulating block 170, which is combined with the bottom 114 of the fixing ring 110, and the fixing member 160 is fixed to the insulating block 170, thereby indirectly fixing the heating plate 130 to the bottom 114 of the fixing ring 110.

[0034] like Figure 5 , Figure 6 and Figure 7 As shown, the wafer carrier 100 proposed in the embodiment of the utility model. In order to improve the heat conduction between the heating plate 130 and the carrier 120 and avoid the gap of poor contact from reducing the local or average heat conduction coefficient, the wafer carrier 100 also includes a flexible heat-conducting medium 140, which is clamped between the bottom surface 124 of the carrier 120 and the heating plate 130. The preferred embodiment of the flexible heat-conducting medium 140 is a graphite sheet, but the implementation of the flexible heat-conducting medium 140 does not exclude thermal paste, metal foil or other embodiments that are easily deformed and have a high heat conduction coefficient.

[0035] In addition, when the bottom surface 124 of the carrier 120 is directly or indirectly covered by the heating plate 130, the temperature at the center of the carrier 120 is usually higher than the ambient temperature, which affects the uniform temperature on the carrier 120, thereby causing uneven temperature distribution on the surface of the wafer, resulting in inconsistent conditions for operations such as coating and deposition. Accordingly, in the present invention, a shallow groove 124a is provided on the bottom surface 124 of the carrier 120, and the shallow groove 124a is approximately located in the center of the bottom surface 124. When the flexible heat-conducting medium 140 is clamped between the bottom surface 124 of the carrier 120 and the heating plate 130, the flexible heat-conducting medium 140 will fill the shallow groove 124a.

[0036] At this time, the flexible heat-conducting medium 140 in the shallow groove 124a has a relatively large thickness, that is, the distance from the portion of the bottom surface 124 located in the shallow groove 124a to the heating plate 130 will be greater than the distance from the other portions of the bottom surface 124 to the heating plate 130, thereby increasing the local thermal resistance, so that there will not be a large temperature difference between the temperature of the carrier 120 portion and the temperature of other portions. Therefore, the temperature distribution on the surface of the wafer will become more uniform, so that the temperature conditions on the surface of the wafer for operations such as coating and deposition are consistent.

[0037] Specifically, the insulating block 170 is made of a material with a low thermal conductivity coefficient, such as ceramic. The insulating block 170 is used to reduce the heat power of the heating plate 130 through the fixing plate 150 and the fixing member 160 to the fixing ring 110. Therefore, for the heating path of the fixing ring 110, only the top 112 of the fixing ring 110 is in contact with the carrier 120, thereby reducing the heating of the fixing ring 110 and reducing the thermal expansion of the fixing ring 110.

[0038] Through the wafer carrier 100 with heating function proposed by the utility model, the carrier 120 can maintain a low thermal expansion coefficient configuration to avoid adverse effects on the wafer during wafer processing. The wafer carrier 100 is composed of multiple different components, and low-cost materials can be selected for components other than the carrier 120, thereby reducing the overall manufacturing cost of the wafer carrier 100 with heating function.

[0039] The above is merely an embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. That is, all equivalent changes and modifications to the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of protection requested by the present invention.

Claims

1. A wafer carrier device with heating function, characterized in that: Included are: A fixing ring surrounding the hollow area, and the fixing ring has a top and a bottom, wherein the hollow area communicates the top and the bottom; A carrier plate having a carrying surface and a bottom surface, wherein the carrier plate is detachably fixed to the top of the fixing ring and covers the hollow area with the bottom surface; wherein the thermal expansion coefficient of the carrier plate is smaller than the thermal expansion coefficient of the fixing ring; as well as A heating plate is arranged in the hollow area and is used for heating the bottom surface.

2. The wafer carrier with heating function according to claim 1, characterized in that: The linear thermal expansion coefficient of the thermal expansion coefficient of the carrier is less than 15 x 10-6 / °C.

3. The wafer carrier with heating function according to claim 1, characterized in that: A flexible heat-conducting medium is also included and is clamped between the bottom surface of the carrier and the heating plate.

4. The wafer carrier with heating function according to claim 3, characterized in that: A shallow groove is arranged on the bottom surface of the carrier, and the flexible heat-conducting medium is filled in the shallow groove.

5. The wafer carrier with heating function according to claim 4, characterized in that: The shallow groove is located at the center of the bottom surface.

6. The wafer carrier with heating function according to claim 1, characterized in that: A gas channel is formed inside the carrier, and the carrier has a gas extraction port. The gas channel communicates with the carrier surface and the gas extraction port, and the gas channel forms a plurality of ventilation openings on the carrier surface.

7. The wafer carrier with heating function according to claim 6, characterized in that: The carrier plate further includes a plurality of air guiding grooves extending on the carrying surface and at least extending to one of the ventilation openings.

8. The wafer carrier with heating function according to claim 7, characterized in that: The air extraction port is located on the side of the carrier plate.

9. The wafer carrier with heating function according to claim 1, characterized in that: It also includes a fixing plate and a fixing member; the fixing plate is used to carry the heating plate, and the fixing member is combined with the edge of the fixing plate to support the heating plate.

10. The wafer carrier with heating function according to claim 9, characterized in that: It also includes an insulating block, which is combined with the bottom of the fixing ring, and the fixing member is fixed to the insulating block.

Images