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EVIDENCE FOR REVERSIBLE DISSOCIATIVE ADSORPTION IN THE REACTION OF MOLECULAR CHLORINE WITH GALLIUM-ARSENIDE

TitleEVIDENCE FOR REVERSIBLE DISSOCIATIVE ADSORPTION IN THE REACTION OF MOLECULAR CHLORINE WITH GALLIUM-ARSENIDE
Publication TypeJournal Article
Year of Publication1995
AuthorsWong, KC, Ogryzlo, EA
JournalCanadian Journal of Chemistry-Revue Canadienne De Chimie
Volume73
Pagination735-739
Date PublishedMay
Type of ArticleArticle
ISBN Number0008-4042
Keywordsbromine, DOPED POLYCRYSTALLINE SILICON, ETCHING, GALLIUM ARSENIDE, IODINE, KINETICS, MOLECULAR CHLORINE, RATE CONSTANTS
Abstract

The reaction of molecular chlorine with the (100) face of a gallium arsenide crystal has been studied at pressures of Cl-2 between 0.10 and 9.0 Torr and in the temperature range from 90 to 110 degrees C. In contrast to an earlier report, the etch rate was found to be half order with respect to Cl-2. The similarity of these results to those obtained for the reaction of molecular chlorine and bromine with silicon points to a mechanism in which the gaseous halogen molecule is first physisorbed on the semiconductor surface and then dissociates into chemisorbed atoms. The data indicate that both steps occur reversibly at higher pressures, where the composite half-order rate constant can be represented by the Arrhenius equation: k(1/2) = 10(13.6+/-2.6) mu m min(-1) Torr(-1/2) e(-(100+/-19kJ) (mol-1/RT)) At low pressures the first-order rate constant is given by the equation: k(1) = 10(10.4+/-2.3) mu m min(-1) Torr(-1) e(-(76+/-16kJ) (mol-1/RT)

URL<Go to ISI>://A1995RG95900014