Browse Prior Art Database

No Edge Contact Wafer Orientor

IP.com Disclosure Number: IPCOM000082581D
Original Publication Date: 1975-Jan-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 3 page(s) / 57K

Publishing Venue

IBM

Related People

Gagne, M: AUTHOR [+2]

Abstract

This tool provides accurate positional and angular orientation alignment of semiconductor wafers, without physically contacting the edges of the wafer. It may be used in semiconductor manufacturing process steps, which require alignment of the wafer prior to being transferred to a photoresist masking step where physical handling is to be minimized.

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No Edge Contact Wafer Orientor

This tool provides accurate positional and angular orientation alignment of semiconductor wafers, without physically contacting the edges of the wafer. It may be used in semiconductor manufacturing process steps, which require alignment of the wafer prior to being transferred to a photoresist masking step where physical handling is to be minimized.

Shown in Fig. 1 is a partial schematic view of the tool which includes an air track support plate 10. Three dual-sensor edge sensing units 12 are mounted in slots in plate 10. Each sensing unit is capable of being clamped to an arm 14 by a clamp 16 responsive to each sensing unit 12. Arms 14 are connected to a floating ring assembly 18 which includes a plurality of controllable vacuum stops 20, for physically clamping the back side of the wafer so that it will move with ring
18.

In the center of the tool is a fixed vacuum chuck 22, which is used to rotate a wafer that has been aligned in the plane of plate 10. In order to drive sensors 12 and floating ring 18, there is provided a drive ring 24 which includes angled slots that cooperate with sensors 12, causing them to move in or out depending upon which direction drive ring 24 is rotated by a motor assembly, not shown. The tool operates to align a wafer in the following sequence:

1. A wafer 26 is transported to the vicinity of the device by a suitable mechanism such as an air track conveyor, and is stopped in a random position over vacuum chuck 22. The center of wafer 26 is indicated by cross 28 and the center of the tool by circle 30. At this time, the wafer 26 is not centered or oriented. Stopping takes place by the application of vacuum to vac...