Untersuchungen zur atomspektroskopischen spurenanalyse in AB-halbleiter-mikroproben—II : Untersuchungen zur bestimmung von Ga-spuren in In und InAs und von In-spuren in Ga, GaAs und GaP durch AAS mit elektrothermischer atomisierung

The atomic-absorption determination of traces of Ga in In, P, As and InAs and of traces of In in Ga, P, As, GaAs and gap is described. The mechanism of the evaporation of the trace element according to the medium used (HCl or HNO₃) is discussed. Nitric acid medium is recommended for analytical determinations. The evaporation of the trace elements and matrices was investigated by means of absorbance vs. time curves. It is shown that a thermal fractionation of AsO^3?₄ and PO^3?₄ matrices and Ga and In traces is possible in the ashing step. In the case of Ga the thermal fractionation of the matrices (In³⁺, In³⁺/AsO^3?₄) from the trace element is possible in the atomization step. The thermal fractionation of In traces from the matrices (Ga³⁺, Ga³⁺/AsO^3?₄, Ga³⁺/Po^3?₄) is impossible. The results and the reasons for the non-specific absorption are discussed. The absolute detection limits are Ga 45 pg, In 35 pg. The relative detection limits are 1 ppm in a 0.1 mg sample.