III-V SEMICONDUCTORS ON SI SUBSTRATES - NEW DIRECTIONS FOR HETEROJUNCTION ELECTRONICS

Excellent device performance at both dc and microwave frequencies has recently been obtained from GaAs based devices grown on Si substrates. In GaAs MESFETs on Si, current gain cutoff frequencies and maximum oscillation frequencies of f//T equals 13. 3 GHz and F//m//a//x equals 13. 3 GHz and f//m//a//x equals 30 GHz have been obtained for 1. 2 mu m devices, which is nearly identical to the performance achieved in GaAs on GaAs technology for direct implant and epitaxial technology. For heterojunction bipolar transistors, current gain cutoff frequencies and maximum oscillation frequencies of f//T equals 30 GHz and f//m//a//x equals 11. 3 GHz have been obtained for emitter dimensions of 4 multiplied by 20 mu m**2. These results compare with the best reported HBT on GaAs substrates of f//T equals 40 GHz and f//m//a//x equals 26 GHz with much smaller geometry. The growth of III-Vs on Si promises to play an important role in the future of heterojunction electronics.