Browse Prior Art Database

Removal and Recovery of Gallium

IP.com Disclosure Number: IPCOM000091272D
Original Publication Date: 1967-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

VanSteenburgh, JJ: AUTHOR

Abstract

This method is for removing and recovering gallium from semiconductor wafers. Gallium is applied to wafers to improve heat conduction during sputtering operations. Gallium has the right thermal properties to perform the function and has the added advantage of being a liquid near room temperature. Following the sputtering operation, the wafer must be cleaned. Due to the high cost of gallium, its recovery is very desirable.

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Removal and Recovery of Gallium

This method is for removing and recovering gallium from semiconductor wafers. Gallium is applied to wafers to improve heat conduction during sputtering operations. Gallium has the right thermal properties to perform the function and has the added advantage of being a liquid near room temperature. Following the sputtering operation, the wafer must be cleaned. Due to the high cost of gallium, its recovery is very desirable.

This method consists of placing the wafer to be cleaned face down on a rotatable vacuum pedestal mounted within a TEFLON* cup, spinning the wafer, touching a Q-T1P**, or like instrument, that has been dipped in water to the spinning wafer, placing a few drops of isopropyl alcohol on the wafer, and spinning the wafer dry. The application of the tip dipped in water to the spinning surface causes all of the gallium to be spun from the wafer and deposited on the walls of the cup. The gallium can be easily recovered since it does not adhere to the TEFLON cup.

The method results in complete recovery of gallium, ease and simplicity of operation, and reduced breakage of wafers. *Trademark of E.I. du Pont de Nemours and Co. **Trademark of Cheesebrough-Pond's, Inc.

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