A HIGH-PERFORMANCE P-CHANNEL TRANSISTOR - BETA-MOS FET

We have fabricated a beta (Bipolar Enhanced Transistor Action) MOS FET device which operates in combined FET and bipolar modes, while perfec tly maintaining the MOSFET circuit configuration with extended operati onal voltage up to -4 volts due to gate-voltage-controlled base resist ance of the parasitic lateral bipolar transistor. Three types of gate- to-substrate contact were investigated including ultrathin tunnelling barriers. The p-channel beta-MOS FET showed dramatic improvements in t ransconductance by a factor of 4 while maintaining the same threshold voltage (approximate to-1 V) compared with conventional MOS structures . This result of 1.3 mu m beta-MOS FET is favorably compared with one tenth of a micron p-MOS FET.