Influence of Interfacial Oxygen and Carbon on Misfit Dislocation Generation in SiGe Epitaxial Layers

The influence of interfacial oxygen (O) and carbon (C) at the SiGe epi/Si interface on misfit dislocation generation and their impact on embedded SiGe device performance were studied. It is found that the interfacial O and C increased the dislocation nuclei, and degraded the channel hole mobility, resulting in the degradation of its device performance. We concluded that it is indispensable to realize not only the low temperature SiGe growth but also the low temperature in-situ precleaning to improve device performance. By using the low temperature SiGe process at 550{degree sign} C including in-situ precleaning and SiGe growth, high device performance such as saturation drain current (Ion) of 765 μA/μm were achieved at off current (Ioff) of 100 nA/μm at drain bias (VDD) = 1.0 V by suppressing of dislocation generation.