GaAs/AlGaAs MODFET's grown on (100) Ge

GaAs/AlGaAs MODFET's have been grown on (100) oriented Ge substrates by molecular beam epitaxy. Transconductances of 160 mS/mm and 345 mS/mm were measured at 300 and 77 K, respectively. These transconductance values are comparable to those obtained from MODFET's grown on GaAs. The absence of looping in the I-V characteristics and reasonably high transconductances obtained indicated the high quality of the epitaxial layers. To prevent the outdiffusion of Ge to the channel region, a 1-micron-thick superlattice buffer was used as a diffusion barrier. These devices demonstrate the feasibility of integrating III-V technology with Si technology via epitaxial Ge on Si.