Field effect transistors

摘要

A field effect transistor is constructed so that a short section of the channel next to the drain effectively has a higher gate threshold voltage than the rest of the channel. A CMOS circuit using the transistors can be arranged to pass no current between the supply conductors during a change of state. The drain threshold voltage may be a linear function of the gate voltage thus providing a linear voltage amplifier. The high threshold section may be achieved by irradiating a conventional FET whilst a voltage is applied to its drain causing charge storage in the gate insulation, by establishing a voltage gradient near the drain end of the gate metallisation, or by modifying the channel doping near the drain.