We have fabricated strained Ge channel p-type metal-oxide-semiconductor field-effect transistors (p-MOSFETs) on Si₀.₃Ge₀.₇ virtual substrates. The poor interface between silicon dioxide (SiO₂) and the Ge channel was eliminated by capping the strained Ge layer with a relaxed, epitaxial silicon surface layer grown at 400° C. Ge p-MOSFETs fabricated from this structure show a hole mobility enhancement of nearly 8 times that of co-processed bulk Si devices, and the Ge MOSFETs have a peak effective mobility of 1160 cm²/V-s. These MOSFETs demonstrate the possibility of creating a surface channel enhancement mode MOSFET with buried channel-like transport characteristics. / Singapore-MIT Alliance (SMA)

PMOS and NMOS mobility characteristics of the dual channel (strained Si/strained Ge) heterostructure have been reviewed. It is shown that the dual channel heterostructure can provide substantially enhanced mobilities for both electrons and holes. However, germanium interdiffusion from the germanium rich buried layer into the underlying buffer layer could potentially reduce the hole mobility enhancements. / Singapore-MIT Alliance (SMA)