Dynamic threshold MOSFET using accumulated base BJT level shifter for low voltage sub-quarter micron transistor

摘要

A dynamic threshold voltage MOSFET to provide increase drain- to- source saturation current (I.sub.DSsat) and lower off current (I.sub. off) is described. The dynamic threshold voltage MOSFET has a first diffusion- well of a material of a first conductivity type formed at the surface of the substrate to form a bulk region. A source region and a drain region of a material of a second conductivity type are diffused into the diffusion-well. A first gate is then placed on a first oxide surface above the substrate between the source and drain regions. An accumulated base bipolar transistor is then placed on the semiconductor substrate. The base of the accumulated base bipolar transistor is connected to the gate, the emitter is connected to the diffusion-well. A resistor is connected between the emitter of the accumulated base bipolar transistor and a substrate biasing voltage source. A biasing circuit connected to the collector of the accumulated base bipolar transistor to provide a bias voltage for the accumulated base bipolar transistor.