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Formulation for a Family of Silicon Dioxide Etchants

IP.com Disclosure Number: IPCOM000086391D
Original Publication Date: 1976-Sep-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

MacIntyre, MW: AUTHOR [+2]

Abstract

Described is a new etchant solution which is equimolar in ammonium fluoride and hydrofluoric acid, and is especially useful for etching silicon dioxide during semiconductor device fabrication. This formulation takes advantage of the fact that the maximum silicon dioxide etch rate for ammonium fluoride-hydrofluoric acid etchants occurs when the etchants are equimolar.

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Formulation for a Family of Silicon Dioxide Etchants

Described is a new etchant solution which is equimolar in ammonium fluoride and hydrofluoric acid, and is especially useful for etching silicon dioxide during semiconductor device fabrication. This formulation takes advantage of the fact that the maximum silicon dioxide etch rate for ammonium fluoride- hydrofluoric acid etchants occurs when the etchants are equimolar.

The equimolar formulation described above reduces the amount of fluoride usage by approximately 70%, the cost by approximately 10%, and eliminates the need for special ammonium treatment facilities during industrial waste treatment. Such an equimolar etchant formulation further reduces the crystallization temperature of the etchants and the precipitation of reaction products during etching, with its resulting residual oxide problems.

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