Vacuum hold-down apparatus for planarizing a curved semiconductor wafer

Abstract

A vacuum hold down apparatus suitable for holding a wafer in a desired position and orientation includes a vacuum chuck assembly defining a vacuum chuck surface having a vacuum communication aperture, a venturi vacuum generator fixed relative to the vacuum chuck assembly and in communication with the vacuum chuck surface via the vacuum communication aperture, and a positive pressure fluid line in communication with the venturi vacuum generator.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to vacuum chucking apparatus and vacuum chucks, and more particularly to vacuum chucking apparatus for use in the semiconductor industry. BACKGROUND

[0002] Various types of vacuum chucks are known for use in the semiconductor industry. SUMMARY

[0003] The present invention seeks to provide improved vacuum chucking apparatus particularly suitable for use in, but not limited to, the semiconductor industry.

[0004] Thus, according to a preferred embodiment of the present invention, there is provided a vacuum chucking apparatus adapted for holding a wafer in a desired position and orientation, the apparatus comprising: a vacuum chuck assembly defining a vacuum chuck surface having a vacuum communication aperture; a venturi vacuum generator fixed relative to the vacuum chuck assembly and in communication with the vacuum chuck surface via the vacuum communication aperture; and a positive pressure fluid line in communication with the venturi vacuum generator.

[0005] According to a preferred embodiment of the present invention, both the vacuum chuck assembly and the venturi vacuum generator are mounted on a moveable stage.

[0006] According to a preferred embodiment of the present invention, the positive pressure fluid line is a flexible fluid line.

[0007] According to a preferred embodiment of the present invention, the vacuum chucking apparatus further comprises a fixed positive pressure fluid source coupled to the venturi vacuum generator mounted on the moveable stage via the positive pressure fluid line.

[0008] Preferably, the vacuum chuck surface is rotatable relative to the vacuum chuck assembly.

[0009] According to a preferred embodiment of the present invention, the moveable stage is an X-Y moveable stage.

[0010] Preferably, the vacuum chuck assembly comprises a vacuum chuck surface defining element rotatable relative to the venturi vacuum generator. Additionally, the venturi vacuum generator is coupled to the vacuum chuck surface of the vacuum chuck surface defining element via a central vacuum manifold and conduit assembly having a rotatable vacuum connection to the vacuum chuck surface defining element.

[0011] According to a preferred embodiment of the present application, the venturi vacuum generator is coupled to the vacuum chuck surface defining elements of the vacuum chuck surface via a plurality of vacuum ports and a plurality of vacuum conduits connected to a corresponding plurality of vacuum input ports of the central vacuum manifold and conduit assembly. Additionally, the central vacuum manifold and conduit assembly includes a manifold connected to the vacuum input ports and includes a single vacuum output conduit portion coupled to the rotatable vacuum connection.

[0012] According to a preferred embodiment, the apparatus further includes an additional vacuum connection in communication with the vacuum chuck surface via the vacuum communication aperture.

[0013] According to a preferred embodiment, the vacuum hold down device is operable to selectively supply vacuum to the vacuum chuck assembly from the venturi vacuum generator or from the additional vacuum connection. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present application will be more fully understood and appreciated by

[0015] Figure 1A , 1B Figs. 1A, IB, and 1C are simplified perspective illustrations showing portions of a semiconductor wafer processing machine constructed and operable in accordance with a preferred embodiment of the present application;

[0016] Figure 2A , 2B Figs. 2A, 2B, and 2C are simplified perspective illustrations of a moveable stage assembly forming portions of a semiconductor wafer processing machine of Figures 1A to 1C and show flexible positive fluid pressure connections to a venturi sub-assembly forming portions thereof;

[0017] Figure 3A , 3B Figs. 3A, 3B, and 3C are simplified respective perspective assembly, perspective partial exploded, and cross-sectional view illustrations showing a venturi sub-assembly of Figures 2A to 2C and a vacuum connection between the central vacuum manifold and conduit assembly coupled to an aperture in a vacuum hold down surface of a moveable stage assembly of Figures 2A to 2C ;

[0018] Figure 4A Figs. 4A and 4B are respective exploded and cross-sectional view illustrations of the central vacuum manifold and conduit assembly of 4B ; Figures 3A to 3C

[0019] Figure 5A , 5B Figs. 5A, 5B, and 5C are simplified top view illustrations of the moveable stage assembly of Figures 3A to 4B in three different typical operable orientations; and ​

[0020] Figure 6 For Figures 1A to 5C simplified schematic illustration of an additional embodiment of a semiconductor wafer processing machine. DETAILED DESCRIPTION

[0021] Reference is now made to Figure 1A , 1B and 1C, which are simplified perspective illustrations taken from various viewpoints showing portions of a semiconductor wafer processing machine constructed and operable in accordance with a preferred embodiment of the present application, and to Figure 2A , 2B and 2C, which are simplified perspective illustrations of a moveable stage assembly forming portions of a semiconductor wafer processing machine, and showing flexible positive fluid pressure connections to a venturi subassembly forming portions thereof. Figures 1A to 1C

[0022] As seen in Figures 1A to 2C , a vacuum hold down apparatus is seen suitable for holding a semiconductor wafer in a desired position and orientation, forming part of a semiconductor wafer processing machine 100, such as the Archer™ 600 commercially available from KLA-Tencor Corporation of Milpitas, California, USA. Figures 1A to 1C As seen in particular in , a positive pressure source, such as a positive pressure outlet provided in a manufacturing facility and coupled to an air compressor, is coupled via one or more positive pressure conduits 102 to a positive pressure controller 104, which includes in particular a manually operable pressure shut off switch. An additional one or more flexible positive pressure conduits 106 provide positive pressure supply from the pressure controller 104 to a moveable stage assembly 110.

[0023] The moveable stage assembly 110 can be any suitable moveable stage assembly 110 arranged for selectable X and Y direction displacement of a rotary vacuum chuck assembly 120. The vacuum chuck assembly 120 is operable for selectable rotational positioning of a vacuum chuck surface defining element 130 having a vacuum communication aperture 132 at the center of a vacuum chuck surface 134.

[0024] Figures 3A to 3C As seen inAs seen in FIG. 1, a particular feature of embodiments of the present application is that the venturi vacuum generator 150 is fixed relative to the vacuum chuck assembly 120 for providing vacuum to the vacuum chuck surface defining element 130. The venturi vacuum generator 150 receives a positive pressure fluid flow (typically a flow of air at a pressure of 8 bar) via the flexible positive pressure conduit 106. The venturi generator 150 is preferably a VRL100-100202 commercially available from Nihon Pisco Co., Ltd. of Okaya, Nagano, Japan and includes at least one positive pressure input connector port 152 and at least one vacuum port 154.

[0025] The venturi vacuum generator 150 is preferably in communication with the vacuum chuck surface defining element 130 via a plurality of vacuum ports 154 and a plurality of vacuum conduits 156 connected to a corresponding plurality of vacuum input ports 158 of a central vacuum manifold and conduit assembly 160 having a rotatable vacuum connection 162 to the vacuum chuck surface defining element 130 at the vacuum communication apertures 132.

[0026] It will be appreciated that because the venturi vacuum generator 150 is in close proximity to the vacuum chuck surface 134, the reach of the vacuum conduits 156 is shortened and vacuum losses are thereby minimized.

[0027] Referring now additionally to FIG. 2, Figure 4A and 4B the central vacuum manifold and conduit assembly 160 also preferably includes a manifold 164 connected to the vacuum input ports 158 and includes a single vacuum output conduit portion 166 coupled to the rotatable vacuum connection 162.

[0028] Referring now additionally to FIG. 3, Figures 5A to 5C it is seen that the vacuum chuck surface defining element 130 can have various positions in the X-Y plane and various rotational orientations relative to the vacuum chuck assembly 120.

[0029] As seen in FIG. 4, Figure 6 in additional embodiments of the present application, the vacuum chuck assembly 120 is connected to both the venturi vacuum generator 150 and an additional vacuum source 180. The venturi vacuum generator 150 is coupled to a positive pressure source 182, such as a positive pressure outlet provided in a manufacturing facility. The additional vacuum source 180 is a vacuum source other than the venturi vacuum generator 150, such as a vacuum outlet provided in a manufacturing facility.

[0030] Vacuum is selectively provided to the vacuum chuck surface defining element 130. Initially, vacuum is provided to the vacuum chuck surface defining element 130 by the venturi vacuum generator 150, and when the vacuum sensor 186 provides an indication that a sufficient vacuum has been established at the vacuum chuck surface defining element 130, the additional vacuum source 180 provides vacuum to the vacuum chuck surface defining element 130 and the venturi vacuum generator 150 is turned off.

[0031] It should be appreciated that in additional embodiments shown in Figure 6 the center vacuum manifold and conduit assembly 160 includes an additional vacuum input port 158 to accommodate an additional flexible vacuum connector in communication between the additional vacuum source 180 and the vacuum communication aperture 132. Similarly, in additional embodiments shown in Figure 6 the semiconductor wafer processing machine 100 includes a plurality of additional fittings and tubing necessary for full functioning of the additional vacuum source 180.

[0032] Those of skill in the art will appreciate that the application is not limited to what has been specifically shown and described herein. Rather, the application includes all modifications and variations of the concept herein disclosed and all equivalents falling within the scope of the application.

Claims

1. A vacuum chucking apparatus suitable for holding a wafer in a desired position and orientation, the apparatus comprising: i. a vacuum chuck assembly defining a vacuum chuck surface having a vacuum communication aperture; ii. a venturi vacuum generator fixed relative to the vacuum chuck assembly and in communication with the vacuum chuck surface via the vacuum communication aperture; and iii. a positive pressure fluid line in communication with the venturi vacuum generator; wherein the vacuum chuck assembly includes a vacuum chuck surface defining element that rotates relative to the venturi vacuum generator.

2. The vacuum chucking apparatus of claim 1, and wherein both the vacuum chuck assembly and the venturi vacuum generator are mounted on a moveable stage.

3. The vacuum chucking apparatus of claim 2, and wherein the positive pressure fluid line is a flexible fluid line.

4. The vacuum chucking apparatus of claim 3, and further comprising a fixed positive pressure fluid source coupled to the venturi vacuum generator mounted on the moveable stage via the positive pressure fluid line.

5. The vacuum chucking apparatus of claim 1, and wherein the vacuum chuck surface rotates relative to the vacuum chuck assembly.

6. The vacuum chucking apparatus of claim 2, and wherein the moveable stage is an X-Y moveable stage.

7. The vacuum chucking apparatus of claim 1, and wherein the venturi vacuum generator is coupled to the vacuum chuck surface of the vacuum chuck surface defining element via a central vacuum manifold and conduit assembly having a rotatable vacuum connection to the vacuum chuck surface defining element.

8. The vacuum chucking apparatus of claim 7, and wherein the venturi vacuum generator is coupled to the vacuum chuck surface of the vacuum chuck surface defining element via a plurality of vacuum ports and a plurality of vacuum conduits connected to a plurality of corresponding vacuum input ports of the central vacuum manifold and conduit assembly.

9. The vacuum chucking apparatus of claim 8, and wherein the central vacuum manifold and conduit assembly comprises a manifold connected to the vacuum input ports and includes a single vacuum output conduit portion coupled to the rotatable vacuum connection.

10. The vacuum chucking apparatus of claim 2, and wherein the vacuum chuck surface rotates relative to the vacuum chuck assembly.

11. The vacuum chucking apparatus of claim 2, and wherein the moveable stage is an X-Y moveable stage.

12. The vacuum chucking apparatus of claim 2, and wherein the vacuum chuck assembly includes a vacuum chuck surface defining element that rotates relative to the venturi vacuum generator.

13. The vacuum chucking apparatus of claim 12, and wherein the venturi vacuum generator is coupled to the vacuum chuck surface of the vacuum chuck surface defining element via a central vacuum manifold and conduit assembly having a rotatable vacuum connection to the vacuum chuck surface defining element.

14. The vacuum press apparatus of claim 13 and wherein the venturi vacuum generator is coupled to the vacuum chuck surface of the vacuum chuck surface defining element via a plurality of vacuum ports and a plurality of vacuum conduits connected to a plurality of corresponding vacuum input ports of the central vacuum manifold and conduit assembly.

15. The vacuum press apparatus of claim 14 and wherein the central vacuum manifold and conduit assembly includes a manifold connected to the vacuum input ports and includes a single vacuum output conduit portion coupled to the rotatable vacuum connection.

16. The vacuum press apparatus of claim 1 and further comprising an additional vacuum connection in communication with the vacuum chuck surface via the vacuum communication aperture.

17. The vacuum press apparatus of claim 16 and wherein the vacuum press apparatus is operable to selectively supply vacuum to the vacuum chuck assembly from either the venturi vacuum generator or from the additional vacuum connection.

18. The vacuum press apparatus of claim 2 and further comprising an additional vacuum generator in communication with the vacuum chuck surface via the vacuum communication aperture and wherein the additional vacuum generator is mounted on the moveable object table.

19. The vacuum press apparatus of claim 18 and wherein the vacuum press apparatus is operable to selectively supply vacuum to the vacuum chuck assembly from either the venturi vacuum generator or from the additional vacuum generator.

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