Browse Prior Art Database

Wafer Holder

IP.com Disclosure Number: IPCOM000076523D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Walker, EJ: AUTHOR

Abstract

Figs. 1, 2, and 3 show top, side, and bottom views, respectively, of a vacuum operated semiconductor wafer holder which positions a wafer from its front surface, thereby allowing it to be flattened over the whole front surface. Fig. 1 shows a top view of wafer holder 1, which comprises a circular metal plate 2 in which a grating 3 is formed by machining or etching techniques well known the metallurgical arts. Each element of grid 3 has a triangular shape as indicated in Fig. 2. The base of each triangular element of grid 3 contains grooves 4, to which suction is applied, so that a semiconductor wafer 5 can be pulled by the resulting vacuum against the flat surface of grid 3.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 76% of the total text.

Page 1 of 2

Wafer Holder

Figs. 1, 2, and 3 show top, side, and bottom views, respectively, of a vacuum operated semiconductor wafer holder which positions a wafer from its front surface, thereby allowing it to be flattened over the whole front surface. Fig. 1 shows a top view of wafer holder 1, which comprises a circular metal plate 2 in which a grating 3 is formed by machining or etching techniques well known the metallurgical arts. Each element of grid 3 has a triangular shape as indicated in Fig. 2. The base of each triangular element of grid 3 contains grooves 4, to which suction is applied, so that a semiconductor wafer 5 can be pulled by the resulting vacuum against the flat surface of grid 3. Vacuum is applied via hole 6, which is in turn connected to a gallery 7 which extends about the periphery of grid 3 where it is connected at four points via holes 8 to grooves 4, all of which are interconnected and terminate in galleries 9, as shown in Fig. 3. Because of the interconnection of grooves 4 to galleries 9, suction can be uniformly applied to the surface of semiconductor wafer 5, causing it to be flattened against the bases of the triangular elements of grid 3. A cover plate 10 covers gallery 7, completing the structure and maintaining the air-tight integrity of the over-all vacuum arrangement,

In actual use, wafer 5 is held against the bases of the elements of grid 3 by applying suction to grooves 4. Cover plate 10 contains an aperture, not shown, which permits light...