Browse Prior Art Database

Wafer Holder

IP.com Disclosure Number: IPCOM000048603D
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Wojciekofsky, E: AUTHOR [+2]

Abstract

This wafer holder provides accurate orientation of an 82 mm SP OT wafer for measurement of particulate contamination of the mask side of the tool.

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Wafer Holder

This wafer holder provides accurate orientation of an 82 mm SP OT wafer for measurement of particulate contamination of the mask side of the tool.

As shown in Fig. 1, the holder consists of a block 10 of plastic, typically nylon or polyvinylchloride 4.5 inches square and one-quarter inch thick. A centrally disposed hole 11 (3.0 inches) is cut through the block to expose the lower surface of a wafer 12 (shown in phantom). The wafer 12 is retained and aligned by a semicircular ledge 13 concentric with the hole 11 and extending tangentially therefrom to the bottom edge of the block. The major diameter of the ledge and the spacing between the parallel shoulders is typically 3.26 inches to accept an 82 mm wafer with clearance.

Fig. 2 shows the reduced thickness portion 14 bounded by the hole 11, the parallel portions of the ledge 13 and the bottom edge of the block. This cutaway portion of the block provides a clearance of 0.025 inch between the bottom surface of the wafer and the surface of the holder to prevent abrasion of the wafer as it is inserted into and removed from the holder.

The relative dimensions of the hole 11 and the ledge 13 are such as to provide a horizontal ledge of 0.13 inch. As shown in Fig. 3, a restraining tab 15A (of which there are three) is mounted in a recess in the block 10 by a screw fastener.

The illustrative dimensions have been chosen for compatibility with a given wafer geometry and instrument configuration. Other wafer si...