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Elimination of Crystal Growth and Films in Bare Silicon

IP.com Disclosure Number: IPCOM000084226D
Original Publication Date: 1975-Oct-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Edel, WA: AUTHOR [+3]

Abstract

This process eliminates crystal growth and film formation in silicon windows during diffusion processes which are detrimental to the yield of the semiconductor devices. For example, during the diffusion of a subcollector into a semiconductor substrate, crystals and/or an undesirable film form in the subcollector windows of the substrate. This adversely affects the subsequent photolithographic and epitaxial growth processes.

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Elimination of Crystal Growth and Films in Bare Silicon

This process eliminates crystal growth and film formation in silicon windows during diffusion processes which are detrimental to the yield of the semiconductor devices. For example, during the diffusion of a subcollector into a semiconductor substrate, crystals and/or an undesirable film form in the subcollector windows of the substrate. This adversely affects the subsequent photolithographic and epitaxial growth processes.

Etching the diffusion windows prior to the diffusion step with a suitable silicon etch which does not leave a residue eliminates the problem. The preferred etchant is a mixture of nitric, glacial acetic and hydrofluoric acids containing around 5% of elemental iodine.

Due to circuit considerations, the amount of silicon which is etched away should be kept to a minimum.

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