SPECTROPHOTOMETRIC AND POLAROGRAPHIC METHODS FOR THE DETERMINATION OF SILICON AT NG/G LEVELS IN GALLIUM-ARSENIDE
Journal
Fresenius Zeitschrift Fur Analytische Chemie
Journal Volume
325
Journal Issue
3
Pages
272-277
Date Issued
1986
Author(s)
Yang, M. H.
Abstract
Spectrophotometric and differential pulse polarographic determinations of silicon in gallium arsenide as heteropoly acid have been established. The analysis comprises decomposition with a mixture of hydrochloric acid and bromine in a PTFE vessel, elimination of matrix elements by evaporation of arsenic as arsenic trichloride and extraction of gallium as gallium tetrachloro-complex anion by di-isopropyl ether, and finally spectrophotometric determination of silicomolybdenum blue or polarographic determination of β-silicomolybdic acid. Optimization of sample pretreatment procedures and instrumental determination have been carefully elaborated. The detection limits of the developed methods were found to be 7 ppb and 5 ppb, respectively, for spectrophotometry and polarography. The proposed methods have been practically applied to the analysis of various Si-doped samples. The results obtained by the chemical methods are compared with those from the electrical measurement and the discrepancies found are discussed. © 1986 Springer-Verlag.
Type
journal article