Влияние отжига на свойства слоев Ge : Sb/Si(001) с концентрацией сурьмы выше уровня ее равновесной растворимости в германии

Abstract

The impact of rapid thermal treatment on electrical and luminescent properties of Ge:Sb/Si(001) layers which have Sb concentration much higher than the equilibrium solubility limit was investigated. Local modifications of such properties throughout the structure’s depth were revealed using precise wet chemical etching. It was obtained that at relatively low annealing temperatures ( 500°С) the changes of electron concentration and photoluminescence response may occur without any remarkable diffusion-related redistribution of dopant atoms. For the relatively high ( 700°С) annealing temperatures the changes of electrical and optical properties after anneal are caused by the significant Sb bulk diffusion and desorption from the sample surface. In particular Sb bulk diffusion leads to the formation of doped regions in the initially undoped areas which further contribute to the resulting structure conductivity and its photoluminescence signal.