Browse Prior Art Database

Removal of Palladium Gold from Scanning Electron Microscope Wafers for Reuse of Same

IP.com Disclosure Number: IPCOM000050865D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Sutton, RJ: AUTHOR

Abstract

When the photoresist layer on an integrated circuit wafer is desired to be examined under a scanning electron microscope (SEM), the photoresist layer must be coated with a layer of palladium gold in order to enable the examination of the contours of the photoresist itself. Under earlier practices, after the wafer had been examined under the SEM, the wafer was scrapped because the palladium gold layer could not be removed. The invention disclosed herein is a process to enable the easy removal of the palladium gold layer. The photoresist beneath the palladium gold is slowly softened and dissolved in the exposed areas by immersing the semiconductor chip in a photoresist developer.

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Removal of Palladium Gold from Scanning Electron Microscope Wafers for Reuse of Same

When the photoresist layer on an integrated circuit wafer is desired to be examined under a scanning electron microscope (SEM), the photoresist layer must be coated with a layer of palladium gold in order to enable the examination of the contours of the photoresist itself. Under earlier practices, after the wafer had been examined under the SEM, the wafer was scrapped because the palladium gold layer could not be removed. The invention disclosed herein is a process to enable the easy removal of the palladium gold layer. The photoresist beneath the palladium gold is slowly softened and dissolved in the exposed areas by immersing the semiconductor chip in a photoresist developer. The palladium gold layer will then begin to peel off in large pieces and, with the assistance of mechanical agitation, the metal layer will completely loosen, thereby enabling its complete removal and the salvaging of the integrated circuit wafer. Since palladium and gold are precious metals, they can be easily reclaimed from the developer solution by filtration to separate the metal film.

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