A DEEP-SUBMICROMETER MICROWAVE DIGITAL CMOS SOS TECHNOLOGY

0.35-mu-m complementary metal-oxide-semiconductor (CMOS)/silicon-on-sapphire (SOS) n- and p-channel MOSFET's with a metal-over-polysilicon T-gate structure for monolithic microwave integrated circuit (MMIC) and digital applications are reported. The measured values for the current-gain cutoff frequency f(T) were greater-than-or-equal-to 20 GHz for both n-channel and p-channel devices, and the values for the unilateral power-gain cutoff frequency f(MAX) were 37 GHz for the p-channel and 53 GHz for the n-channel MOSFET's. The low effective resistance of the T-gate structure contributed to the very high f(MAX) values. It is believed that these are the highest f(T) and f(MAX) values ever reported for MOS devices. This work demonstrates the potential of SOS submicrometer MOSFET's for microwave circuit applications.