Wafer chuck, chuck preparation method and wafer processing equipment

Abstract

The invention provides a wafer chuck, a chuck preparation method and wafer processing equipment, the chuck comprises a plurality of mutually spliced chuck units, and each chuck unit is provided with an electrostatic adsorption part, a temperature control part and a bearing surface used for contacting a borne object. The bearing faces of the multiple chuck units jointly form the chuck face of the chuck. Based on the technical scheme, the chuck whole machine is formed by splicing the multiple integrated chuck units, and the uniformity of the adsorption force and the temperature of all the positions on the chuck for adsorbed objects can be adjusted and controlled in a targeted mode.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer chucks, and in particular to a wafer chuck, a chuck preparation method and wafer processing equipment. Background Art

[0002] Wafer chucks are widely used in chip manufacturing and semiconductor preparation processes. Currently, there are chucks with temperature regulation functions, which can mainly combine temperature control to achieve electrostatic adsorption of wafers or further realize heating and temperature control of wafers in certain process flows.

[0003] Current wafer chucks with temperature regulation functions usually have an overall water-cooling or air-cooling temperature regulation system on the back. Although this method can control the temperature of the chuck, the chuck will have uneven temperature, which will lead to uneven temperature of the wafer or other supported objects, local temperature abnormalities and other problems. This has an impact on the process manufacturing with strict requirements on temperature uniformity and is not conducive to semiconductor production.

[0004] Therefore, a wafer chuck, a chuck preparation method and a wafer processing device are proposed to solve the problem of uneven chuck temperature in the prior art. Summary of the invention

[0005] In order to solve the problem of uneven temperature of the chuck in the prior art, the present application proposes a wafer chuck, a chuck preparation method and a wafer processing equipment.

[0006] In a first aspect, a wafer chuck proposed in the present invention comprises a plurality of chuck units spliced ​​together, each of the chuck units having an electrostatic adsorption portion, a temperature control portion and a carrying surface for contacting an object to be carried, and the carrying surfaces of the plurality of chuck units together constitute the chuck surface.

[0007] In one embodiment, the chuck has a plurality of chuck unit groups radially distributed with the center of the chuck surface as the center of the circle, each of the chuck unit groups includes at least one chuck unit, and the plurality of chuck units in the same chuck unit group are arranged in sequence along the circumferential direction.

[0008] In one embodiment, the chuck unit includes a base, an electrode layer covering the surface of the base and serving as the electrostatic adsorption part, and a dielectric layer covering the electrode layer. A heat exchange medium flow channel serving as the temperature control part and an electrode terminal connected to and conducting the electrode layer are provided in the base.

[0009] In one embodiment, the base includes a substrate and a cover plate, the substrate and the cover plate are in surface contact and interlocked with each other, and the electrode layer is covered on the surface of the cover plate;

[0010] Wherein, a groove body extending along a preset path is provided on the surface where the base body and the cover plate are buckled, and the cover plate closes the open part of the groove body and forms the heat exchange medium flow channel.

[0011] In one embodiment, the heat exchange medium flow channel extends in a plane parallel to the bearing surface of the chuck unit, and the extension path of the heat exchange medium flow channel is in a spiral shape that diverges outward from the center of the base.

[0012] In one embodiment, the electrode post is embedded in the center of the substrate, and the end of the electrode post passes through the electrode via hole provided on the cover plate to connect to the electrode layer.

[0013] In a second aspect, the present invention provides a method for preparing a chuck, comprising:

[0014] forming an electrode layer and a dielectric layer in sequence on the surface of the cover plate;

[0015] The cover plate having the electrode layer and the dielectric layer is buckled and connected to the surface of the substrate having the groove body, so that the groove body is surrounded to form a heat exchange medium flow channel;

[0016] A plurality of chuck units formed by buckling the cover plate and the base are spliced ​​according to a preset layout, and the surface of the dielectric layer of each chuck unit is kept in the same plane.

[0017] In one embodiment, after a plurality of chuck units formed by buckling the cover plate and the base are spliced ​​according to a preset layout, the method further comprises:

[0018] The electrode layer and the heat exchange medium flow channel of each chuck unit are connected to the corresponding power supply and medium circulation pipeline respectively.

[0019] In one embodiment, it further comprises:

[0020] Before splicing, each of the chuck units is debugged;

[0021] After the splicing, the chuck machine formed by splicing a plurality of the chuck units is debugged.

[0022] In one embodiment, the buckling connection between the cover plate and the base and the splicing of the plurality of chuck units may be achieved by bonding, brazing or co-firing.

[0023] In one embodiment, the electrode layer and the dielectric layer are formed by screen printing, physical vapor deposition or chemical vapor deposition.

[0024] In a third aspect, the present invention proposes a wafer processing device, which includes the above-mentioned wafer chuck and thus has all the technical effects thereof.

[0025] The above technical features can be combined in various suitable ways or replaced by equivalent technical features as long as the purpose of the present invention can be achieved.

[0026] A wafer chuck, a chuck preparation method and a wafer processing device provided by the present invention have at least the following beneficial effects compared with the prior art:

[0027] A wafer chuck, a chuck preparation method and a wafer processing device of the present invention, by splicing a plurality of integrated chuck units into a chuck complete machine, can specifically adjust and control the uniformity of the adsorption force and the temperature uniformity of each position on the chuck for the adsorbed object. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein:

[0029] Figure 1 The overall structural schematic diagram of the chuck of the present invention is shown;

[0030] Figure 2 A schematic cross-sectional view of a chuck unit of a chuck of the present invention is shown;

[0031] Figure 3 A schematic diagram showing a heat exchange medium flow channel of a chuck unit of the chuck of the present invention is shown.

[0032] In the drawings, like reference numerals are used for like parts. The drawings are not necessarily to scale.

[0033] Reference numerals:

[0034] 1-chuck unit, 10-base, 11-matrix, 12-cover plate, 121-motor through hole, 13-heat exchange medium flow channel, 20-electrode layer, 30-dielectric layer, 40-electrode terminal. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings.

[0036] Example 1

[0037] An embodiment of the present invention provides a wafer chuck, comprising a plurality of chuck units 1 spliced ​​together, each chuck unit 1 having an electrostatic adsorption portion, a temperature control portion and a carrying surface for contacting a carried object, and the carrying surfaces of the plurality of chuck units 1 together constitute a chuck surface.

[0038] Furthermore, the chuck has a plurality of chuck unit groups distributed radially with the center of the chuck surface as the center of the circle, each chuck unit group includes at least one chuck unit 1, and the plurality of chuck units 1 in the same chuck unit group are arranged in sequence along the circumferential direction.

[0039] Specifically, as shown in the attached figure Figure 1 As shown, the chuck of the present invention mainly adopts a splicing structure, that is, it is formed by splicing multiple chuck units 1, each chuck unit 1 has a bearing surface for contacting the object to be carried, and the bearing surfaces of multiple chuck units 1 together constitute the chuck surface. Based on the electrostatic adsorption part and temperature control part independently set for each chuck unit 1, the temperature and adsorption force of each chuck unit 1 can be adjusted, thereby achieving the adjustment of the adsorption force at different positions of the object (such as a wafer) adsorbed by the chuck, thereby achieving the overall adsorption force and temperature uniform distribution.

[0040] In addition, the shapes and structures of the chucks are different, and the shapes and joint methods of the chuck units 1 are also different. Figure 1 As shown, the disk surface of the chuck in this embodiment is circular, so there are many ways to divide the chuck unit 1, such as tic-tac-toe grid division or as shown in the accompanying drawings. Figure 1 This embodiment takes into account that based on the circular chuck, the layout of the chuck unit 1 must be absolutely symmetrical, so that each position can be adjusted to make the adsorption force and temperature uniform, and then adopt the figure Figure 1 The concentric circles shown are divided. That is, the chuck has multiple chuck unit groups distributed radially with the center of the chuck surface as the center of the circle, and multiple chuck units 1 in the same chuck unit group are arranged in sequence along the circumferential direction. It should be noted that the number of chuck units 1 in each chuck unit group (i.e., the division density) is determined according to actual conditions, and the chuck unit group at the center of the chuck has a limited area size, and can actually be a circular chuck unit 1 as a whole.

[0041] Furthermore, the chuck unit 1 includes a base 10, an electrode layer 20 covering the surface of the base 10 and serving as an electrostatic adsorption part, and a dielectric layer 30 covering the electrode layer 20. The base 10 is provided with a heat exchange medium flow channel 13 serving as a temperature control part and an electrode terminal 40 connected to and conducting the electrode layer 20.

[0042] Specifically, as shown in the attached figure Figure 2 and Figure 3As shown, the surface of the base 10 of the chuck unit 1 is covered with two layers of structure, one is the outermost dielectric layer 30, and the other is the electrode layer 20 between the surface of the base 10 and the dielectric layer 30. Among them, the electrode layer 20 is connected to the power supply through the electrode terminal 40 set in the base 10 to generate electrostatic adsorption force; the surface of the dielectric layer 30 is used as a bearing surface that directly contacts the object to be carried, which is mainly used to isolate the object to be carried from the electrode layer 20 to avoid damage caused by breakdown of the object to be carried under high voltage loading, and at the same time, the electric potential is transferred to the object to be carried through the dielectric layer 30. The heat exchange medium flow channel 13 is mainly used for the circulation of heat exchange medium (liquid cooling or air cooling) to control the temperature of the chuck unit 1 (mainly the surface of the dielectric layer 30 that contacts the object to be carried) due to the heat generated by the electrode layer 20.

[0043] It should be noted that the electrode layer 20 is made of a conductive material with good conductivity, such as silver, gold, platinum or alloys, or any other material with good conductivity and certain heating properties. The dielectric layer 30 is made of a dielectric material, such as glass ceramics, aluminum oxide, aluminum nitride, and silicon nitride.

[0044] Furthermore, the base 10 includes a substrate 11 and a cover plate 12, the substrate 11 and the cover plate 12 are in surface contact and interlocked with each other, and the electrode layer 20 covers the surface of the cover plate 12;

[0045] A groove extending along a preset path is provided on the surface where the base 11 and the cover plate 12 are engaged with each other, and the cover plate 12 closes the open portion of the groove and forms a heat exchange medium flow channel 13 .

[0046] Specifically, as shown in the attached figure Figure 3 As shown, the base 10 adopts a split splicing structure, that is, the base 11 and the cover plate 12 are spliced ​​together, so that it is convenient to process the heat exchange medium flow channel 13 (only need to groove on the surface of the base 11), secondly, it is convenient to process the dielectric layer 30 and the electrode layer 20 (only need to use the cover plate 12 as the basis, eliminating the heavy and large base 11), and thirdly, it is convenient to shorten the entire process (the heat exchange medium flow channel 13 of the base 11 and the dielectric layer 30 and the electrode layer 20 of the cover plate 12 can be processed separately and simultaneously). The area through which the groove on the surface of the base 11 extends covers the entire area of ​​the surface of the base 11.

[0047] Furthermore, the heat exchange medium flow channel 13 extends in a plane parallel to the bearing surface of the chuck unit 1 , and the extension path of the heat exchange medium flow channel 13 is in a spiral shape that diverges outward from the center of the base 10 .

[0048] Specifically, as shown in the attached figure Figure 1As shown, the extension path of the heat exchange medium flow channel 13 (i.e., the groove body on the surface of the substrate 11) is a spiral divergent structure, and the two ends of the path are the inlet and outlet of the heat exchange medium, so that the area through which it extends can completely cover the surface of the substrate 11. Of course, other extension structures can also be used, such as an S-shaped winding structure.

[0049] Furthermore, the electrode post 40 is embedded in the center of the substrate 11 , and the end of the electrode post 40 passes through the electrode via hole provided on the cover plate 12 to connect to the electrode layer 20 .

[0050] Specifically, in this embodiment, the heat exchange medium flow channel 13 adopts a spiral divergent structure based on the center, which is also determined in combination with the heating condition of the electrode layer 20. Figure 3 The electrode post 40 of this embodiment is arranged at the center of the substrate 11, that is, connected to the center of the electrode layer 20, which is conducive to the conduction and heat generation of the electrode layer 20. However, at the same time, the heat generated at the connection point on the general circuit structure will be relatively large. Therefore, the medium inlet of the heat exchange medium flow channel 13 of this embodiment is located at the center of the substrate 11. The heat exchange medium with the lowest temperature input at the first time can better control the temperature of the connection point between the electrode post 40 and the electrode layer 20 at that location.

[0051] Example 2

[0052] An embodiment of the present invention provides a method for preparing a chuck, comprising:

[0053] Step S100: forming an electrode layer and a dielectric layer in sequence on the surface of the cover plate;

[0054] Specifically, the electrode layer and the dielectric layer are sequentially formed on the cover plate, which can be done by screen printing, physical vapor deposition or chemical vapor deposition. In this process, the substrate can also be processed and prepared at the same time or immediately afterwards to prepare the substrate and the groove on the substrate and the electrode posts for connecting the electrode layer.

[0055] Step S200: The cover plate having the electrode layer and the dielectric layer is buckled and connected to the surface of the substrate having the groove body to form a chuck unit, and the groove body is surrounded to form a heat exchange medium flow channel;

[0056] Step S210: Debugging each chuck unit;

[0057] Specifically, the substrate and the cover plate are integrated together by bonding, brazing or co-firing, and the integrated chuck unit is debugged to ensure that the parameters such as the adsorption force, potential and temperature of the dielectric layer are consistent with those of all other chuck units.

[0058] Step S300: splicing a plurality of chuck units formed by buckling the cover plate and the base according to a preset layout, and keeping the surface of the dielectric layer of each chuck unit in the same plane;

[0059] Specifically, multiple chuck units are spliced ​​into a complete chuck. The chuck units can be integrated together by brazing, organic adhesive bonding, ceramic co-firing or slurry bonding and sintering. During the integration process, it is necessary to ensure that the dielectric layers of all chuck units are on the same plane and that the dielectric layer of each chuck unit has a consistent gap with the wafer or the object being supported in the non-working state.

[0060] Step S400: connecting the electrode layer and the heat exchange medium flow channel of each chuck unit to the corresponding power supply and medium circulation pipeline respectively;

[0061] Specifically, an independent medium circulation system (connected to the corresponding medium circulation pipeline) is integrated into each chuck unit, and the medium flow, flow velocity, temperature and adsorption force of the dielectric layer of each chuck unit can be individually controlled. The number of medium circulation systems required for the entire chuck is consistent with the number of chuck units.

[0062] Similarly, an independent power supply system (power supply) is integrated for each chuck unit. The purpose is that the chuck units in different positions have different power supply requirements, and the electric potential and adsorption force generated by the chuck units need to be consistent, so a corresponding number of power supply systems need to be integrated, consistent with the number of chuck units.

[0063] Step S500: Debugging a chuck machine formed by splicing a plurality of chuck units.

[0064] Specifically, the debugging of the chuck includes temperature debugging, adsorption force debugging and potential testing. It is necessary to ensure that the temperature, potential, voltage and adsorption force of each position on the integrated chuck surface are evenly distributed. The debugging logic is basically based on voltage → adsorption force → temperature. The adsorption force is related to temperature and distance, and the medium circulation system and dielectric layer thickness and material need to be adjusted.

[0065] Example 3

[0066] An embodiment of the present invention provides a wafer processing device, including the aforementioned wafer chuck, and thus having all the technical effects thereof.

[0067] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0068] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A wafer chuck, It is characterized in that It comprises a plurality of mutually connected chuck units, each of which has an electrostatic adsorption portion, a temperature control portion and a bearing surface for contacting a carried object, and the bearing surfaces of the plurality of chuck units together constitute the chuck surface.

2. The wafer chuck according to claim 1, It is characterized in that The chuck has a plurality of chuck unit groups distributed radially with the center of the chuck surface as the center of the circle, each of the chuck unit groups includes at least one chuck unit, and the plurality of chuck units in the same chuck unit group are arranged in sequence along the circumferential direction.

3. The wafer chuck according to claim 1, It is characterized in that The chuck unit includes a base, an electrode layer covering the surface of the base and serving as the electrostatic adsorption part, and a dielectric layer covering the electrode layer. A heat exchange medium flow channel serving as the temperature control part and an electrode terminal connected to and conducting the electrode layer are arranged in the base.

4. The wafer chuck according to claim 3, It is characterized in that The base comprises a base body and a cover plate, the base body and the cover plate are in surface contact and interlocked with each other, and the electrode layer covers the surface of the cover plate; Wherein, a groove body extending along a preset path is provided on the surface where the base body and the cover plate are buckled, and the cover plate closes the open part of the groove body and forms the heat exchange medium flow channel.

5. The wafer chuck according to claim 3 or 4, It is characterized in that The heat exchange medium flow channel extends in a plane parallel to the bearing surface of the chuck unit, and the extension path of the heat exchange medium flow channel is in a spiral shape that diverges outward from the center of the base.

6. The wafer chuck according to claim 4, It is characterized in that The electrode post is embedded in the center of the substrate, and the end of the electrode post passes through the electrode via hole provided on the cover plate to connect with the electrode layer.

7. A method for preparing a chuck, It is characterized in that include: forming an electrode layer and a dielectric layer in sequence on the surface of the cover plate; The cover plate having the electrode layer and the dielectric layer is buckled and connected to the surface of the substrate having the groove body, so that the groove body is surrounded to form a heat exchange medium flow channel; A plurality of chuck units formed by buckling the cover plate and the base are spliced ​​according to a preset layout, and the surface of the dielectric layer of each chuck unit is kept in the same plane.

8. The method for preparing a chuck according to claim 7, It is characterized in that After a plurality of chuck units formed by buckling the cover plate and the base are spliced ​​according to a preset layout, the method further includes: The electrode layer and the heat exchange medium flow channel of each chuck unit are connected to the corresponding power supply and medium circulation pipeline respectively.

9. The method for preparing a chuck according to claim 7 or 8, It is characterized in that Also includes: Before splicing, each of the chuck units is debugged; After the splicing, the chuck machine formed by splicing a plurality of the chuck units is debugged.

10. The method for preparing a chuck according to claim 7, It is characterized in that The buckling connection between the cover plate and the base body and the splicing of the plurality of chuck units can be achieved by bonding, brazing or co-firing.

11. The method for preparing a chuck according to claim 7, It is characterized in that The electrode layer and the dielectric layer are formed by screen printing, physical vapor deposition or chemical vapor deposition.

12. A wafer processing device, It is characterized in that Comprising a wafer chuck as described in any one of claims 1 to 6.

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