Vacancy interactions in GaAs

摘要

Isochronal annealing of zinchyphen; or siliconhyphen;doped GaAs as well as undoped semihyphen;insulating or lowhyphen;resistivity materials has been investigated by positron lifetime measurements. For impurity concentrations larger than 4.5times;1017cmminus;3, only monovacancy complexes such as ZnGaVAs, thinsp;SiAsVGa, or AsGaVGaare observed and they yield a positron lifetime of 265plusmn;5 ps. For impurity concentrations less than 1times;1017cmminus;3, divacancies dominate and yield a lifetime of 295plusmn;5 ps. The concentrations of grownhyphen;in vacancies, either VAsor VGa, are both estimated to be in the range of (1ndash;4)times;1017cmminus;3.