p-type SiGe channel modulation doped field-effect transistors with post-evaporation patterned submicrometre Schottky gates

Schottky gate biased p-type MODFETs with an Si_0.65Ge_0.35 channel are presented. A wet-chemical post-evaporation procedure of the Schottky gates allows the reduction of the gate length L_G to submicrometre dimensions (0.5 mu m). The gate length dependence of the transconductance g_me and g_mi is reported. Maximum values are 37 or 103 mS/mm at 300 or 77 K. The devices work in the enhancement mode.