SI AS A DIFFUSION BARRIER FOR GE/GAAS HETEROJUNCTIONS

We compare the electrical characteristics, before and after annealing, of p-Ge/N-GaAs heterojunction diodes to similar diodes which incorporate a nominally 10 Å layer of pseudomorphic Si at the Ge/GaAs interface. Both types of diodes exhibit excellent current-voltage characteristics before annealing. Diodes having no Si interlayer show significant degradation after a 20 min anneal at 640 °C. Diodes incorporating the Si interlayer retain excellent diode characteristics after a 20 min anneal at temperatures as high as 720 °C.