THE BETA-MOSFET - A NOVEL HIGH-PERFORMANCE TRANSISTOR

The bipolar enhanced transistor action (BETA)-MOSFET, operating in a m ixture of FET mode and bipolar mode, has been fabricated. Unlike the l ateral bipolar transistor, its base current can be automatically contr olled by the gate voltage. Hence, the device operating voltage can be in a wide range and is a maximum of -4 V. It is confirmed that the dev ice can be treated as a high-performance MQSFET in circuit analysis. T hree types of device structures, with a gate-substrate contact that in cludes an ultrathin-film tunnel junction, are fabricated and evaluated . In the p-channel BETA-MOSFET, the drain current and the maximum tran sconductance are about four times those of the conventional MOSFET whi le maintaining the same threshold voltage. This result implies that th e BETA-MOSFET with a gate length of 1.3 mu m exhibits a superior perfo rmance equivalent to a 0.1-mu m p-MOSFET. (C) 1997 Scripta Technica, I nc.