EPR measurements were made on two LEC-grown (100) GaAs:Cr wafers. For both samples, [Cr]=2 wt-ppm. The observed Cr2+distributions showed inverted-U type (wafer A) and W-type (wafer B) variations. However, the leakage current (IL) distributions for the respective wafers showed U-type and M-type variations, indicating an inverse correspondence between the IL, and Cr2+distributions. Although a consideration of the compensation mechanism suggests that the Cr2+depletion at the periphery in wafer A is determined by the Cr distribution itself, atomic absorption measurements on the same wafer showed no such depletion of Cr. This result can be explained in terms of the nonuniform distribution of electrically-inactive Cr atoms in the wafer.
ASJC Scopus subject areas
- Physics and Astronomy(all)