MICROX (TM) - AN ALL-SILICON TECHNOLOGY FOR MONOLITHIC MICROWAVE INTEGRATED-CIRCUITS

An improved silicon-on-insulator (SOI) approach offers devices and circuits operating to 10 GHz by providing formerly unattainable capabilities in bulk silicon: reduced junction-to-substrate capacitances in FET's and bipolar transistors, inherent electrical isolation between devices, and low-loss microstrip lines. The concept, called MICROX(TM) (patent pending), is based on the SIMOX process, but uses very high-resistivity (typically > 10 000 OMEGA.cm) silicon substrates. MICROX NMOS transistors of effective gate length (0.25 mum) give a maximum frequency of operation, f(max) of 32 GHz and f(T) of 23.6 GHz in large-periphery (4 x 50 mum) devices with no correction for the parasitic effects of the pads. The measured minimum noise figure is 1.5 dB at 2 GHz with associated gain of 17.5 dB, an improvement over previously reported values for silicon FET's.