A novel windowed growth technique that allows for the exposure of a smooth silicon surface for MOS circuitry between AlGaN/GaN HEMT layers has been developed. A sacrificial oxide based dielectric stack is used to protect regions of the silicon surface before growth by ammonia-MBE. SIMS analysis shows elevated oxygen impurity incorporation in the stress-relief layer, but controllable levels in the C-doped GaN buffer. A Hall mobility of 1.37 × 10 3 cm 2/Vs is measured in the AlGaN/GaN regions. AFM results show a RMS roughness of 0.12 nm on the silicon surface.

Physica Status Solidi (A) Applications and Materials Science
Department of Electronics

Chyurlia, P., Semond, F., Lester, T., Bardwell, J.A., Rolfe, S., Cordier, Y., … Tarr, N.G. (2009). Windowed growth of AlGaN/GaN heterostructures on Silicon 〈111〉 substrates for future MOS integration. In Physica Status Solidi (A) Applications and Materials Science (Vol. 206, pp. 371–374). doi:10.1002/pssa.200824452