Impurity Determination in Group III–V Compounds

Abstract

Methods for determination of trace and ultratrace impurities in group III–V compounds by emission spectroscopy have been investigated. Cleaning of organic and inorganic surface contaminants must be carefully carried out so that ultratrace determination is possible. The method takes advantage of preferential volatilization of group III-V compounds in a dc arc. Sequential exposure is used to improve signal-to-noise ratio. Concentrating the impurities in the electrode by arcing off some of the arsenic in gallium arsenide improves detection limits of relatively nonvolatile elements. The analytical results agree well with other techniques. Electrical properties of compounds also correlate well with the data. The coefficients of variation range from 20 to 40%.