The effects of mechanical planar biaxial strain in Si/SiGe HBT BiCMOS technology

This work presents the results of the effects of mechanical planar biaxial tensile strain applied, post-fabrication, to Si/SiGe HBT BiCMOS technology. 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 saturated drain 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.