High-temperature hole mobility in strained quantum wells

Strained quantum wells are promising candidates on high-speed p-channel field-effect transistors (FET) because of a low effective mass in the split valence band. Here for the first time the high-temperature mobility of holes is studied taking into account realistic wave functions of split light mass subband. The main limit to the mobility at high temperature is put by LO phonons and only this scattering mechanism is considered here. It is shown that deformation coupling with optical phonons is small in quantum wells with a large splitting between the light- and heavy-hole subbands. Analytical expression for the mobility is obtained. Numerical estimates give the upper limit for the mobility as high as a few thousand cm²/V s.