Analysis of electrically active impurity levels in in-situ compounded semi-insulating gallium arsenide

Conductivity and Hall measurements were made on semi-insulating GaAs samples grown with a recently developed process using in-situ compounding with liquid encapsulated (B2O3) Czochralski growth techniques. Mixed conduction analysis in combination with a nomographic analysis of charge balance and conduction was used to elucidate compensation in this material. Given the Cr concentration in one sample, the use of an iterative self-consistent procedure allowed the deduction of total donor and acceptor concentrations for identically prepared Cr-doped and undoped samples. Further analysis yielded the compensation ratio and energy level of the dominant acceptor of a third specimen. A subsequent spark source analysis confirmed the high purity of this in-situ compounded material, as well as the conclusions and utility of the nomographic analysis.