TRACE-ELEMENT PROFILE OF SEMICONDUCTOR-MATERIALS - GALLIUM AND ARSENIC

An ion exchange methodology is described here for the quantitative sep aration and determination of trace elements from high purity gallium, arsenic and a mixture of gallium and arsenic. 0.5-2 g of the matrix is dissolved and subjected to an ion exchange separation process in acid ic/alkaline (hydrochloric acid/ammonia with sodium hydroxide) medium t o preconcentrate the analytes. The desorbed analytes were quantified u sing graphite furnace atomic absorption spectrometry/flame atomic abso rption spectrometry/flame atomic emission spectrometry/neutron activat ion analysis/inductively coupled plasma atomic emission spectrometry. Most of the analytes were found to be present at extreme trace levels. The overall reproducibility of the procedure was 2-10% when compared with the blank values. Separation of the analytes were essentially com plete as the recoveries were >95% which was confirmed by standard addi tion to the matrices and tracer studies. (C) 1998 Elsevier Science B.V . All rights reserved.