Browse Prior Art Database

Chuck-Matching Alignment System

IP.com Disclosure Number: IPCOM000042356D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Cachon, RP: AUTHOR [+2]

Abstract

The alignment of multiple chucks in an exposure tool is accomplished using the optical system of the exposure tool. A first wafer chuck is mechanically registered; a master wafer is placed on the chuck's pedestal; a mask is placed within the tool; and the pedestal is positioned so as to align the wafer to the mask as viewed through the tool optics. This process is repeated for any additional chucks used in the exposure tool. The alignment mechanism used is contained entirely within the chuck itself without any need for an external jig or fixture for proper alignment. As shown in the figure, chuck 1 has structure 2 and pedestal 3 mounted thereon. Structure 2 may be moved with respect to chuck 1 and then locked. This is unlike conventional chuck assemblies wherein pedestal 3 is mounted directly on chuck 1.

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Chuck-Matching Alignment System

The alignment of multiple chucks in an exposure tool is accomplished using the optical system of the exposure tool. A first wafer chuck is mechanically registered; a master wafer is placed on the chuck's pedestal; a mask is placed within the tool; and the pedestal is positioned so as to align the wafer to the mask as viewed through the tool optics. This process is repeated for any additional chucks used in the exposure tool. The alignment mechanism used is contained entirely within the chuck itself without any need for an external jig or fixture for proper alignment. As shown in the figure, chuck 1 has structure 2 and pedestal 3 mounted thereon. Structure 2 may be moved with respect to chuck 1 and then locked. This is unlike conventional chuck assemblies wherein pedestal 3 is mounted directly on chuck 1. Chuck pins 4 provide for mechanical adjustment and orientation of chuck 1. Screws 5, which are located within chuck 1, allow alignment of a wafer (not shown) on pedestal 3. In operation, chuck 1 is first mechanically aligned along the Y axis using registration pins 4. Next, a master wafer containing an alignment pattern is placed on pedestal 3 and vacuum is applied, thus causing the wafer to adhere to the surface of pedestal 3. A mask is then placed in the exposure tool. Utilizing the optics of the exposure tool, pedestal 3 is positioned with the aid of alignment screws 5 so as to align the pattern on the wafer to the pattern on th...