Mechanical planar biaxial strain effects in Si/SiGe HBT BiCMOS technology

The first results of the effects of mechanical planar biaxial tensile strain applied, post fabrication, to Si/SiGe HBT BiCTMOS technology are reported in this work. Planar biaxial tensile strain was applied to the samples, which included both standard Si CMOS, SiGe HBTs, and an epitaxial-base Si BJT control, for both first and second generation SiGe technologies. Device characterization was performed before and after strain, under identical conditions. At a strain level of 0.123%, increases in the saturation current as well as effective mobility are observed for the nFETs. The Si BJT / SiGe HBTs showed a consistent decrease in collector current and hence current gain after strain.