MBE growth of InP-HBT structures on Ge-on-insulator/Si substrates by MBE
MBE growth of InP-based HBTs on GeOI/Si substrates is described. A GaAs buffer is nucleated on the GeOI; then a graded InAlAs metamorphic buffer transitions the lattice constant to InP. TEM shows minimal anti-phase boundaries and limited dislocations propagating into the device layers. Large area DC parameters are similar to LM HBTs grown on InP. Small area devices exhibit peak current gain cutoff frequency (ft) of 170 GHz at 2 mA/mum2 nominal collector current density. Initial work involving selective epitaxial growth on patterned Ge substrates for future integration is also discussed.