Merged CMOS/bipolar technologies and microwave MESFETs utilizing zone-melting-recrystallized SOI films

Two merged CMOS/bipolar technologies utilizing SOI structures have been demonstrated. In each case a single sequence of processing steps was used to fabricate fully isolated CMOS devices and vertical bipolar transistors on the same Si wafer. The CMOS devices were fabricated in a zone-melting-recrystallized SOI film, while the bipolar devices were fabricated either in the SOI film or in epitaxial Si layers grown selectively on the Si substrate. Good electrical characteristics were obtained for the CMOS devices and for both SOI and epitaxial bipolar devices. In addition, microwave MESFETs have been fabricated in zone-melting-recrystallized Si films on bulk fused-silica substrates. These devices exhibited maximum frequency of oscillation of 8-14 GHz. At 1.2 GHz, an optimum noise figure of 2.5 dB and associated gain of 10.4 dB were measured.