Separation of generation lifetimes of Si and SiGe using capacitance-transient measurements on MOS capacitors formed by plasma anodization of Si:Si sub(0.9)Ge sub(0.1):Si substrates

A simple technique leading to the measurement of minority carrier lifetimes of UHV compatible LPCVD Si and SiGe by C-t depth profiling of Metal:Oxide:Si:SiGe:Si structures is reported. A high quality gate oxide is realized by low temperature ( < 100 degree C) plasma anodization thereby reducing any oxidation effects on the underlying epitaxial layer quality. Capacitance response times were observed for an impurity concentration of approximately 2.5x10 super(17) cm super(-3), giving rise to generation lifetimes of the Si and Si sub(0.9)Ge sub(0.1) of > 0.55 and 2.6 mu s respectively, reflective of very high quality epitaxial semiconductor material.