Characteristics of enhancement/depletion (E/D) gate MOSFET fabricated using ion implantation

The E/D gate MOSFET, which has an enhancement and depletion mode region under the same gate, is fabricated by using ion implantation as a tool for shifting threshold voltage. Threshold voltage, transconductance and drain breakdown voltage are studied as functions of implantation dose up to 12 × 10¹² cm^?2.It is found that, at an appropriate dose, the transconductance of this device is determined solely by the channel length of the enhancement mode region, and is larger than that of a short channel MOSFET with a standard structure but with the same drain breakdown voltage. Moreover, the dependence of threshold voltage on substrate bias measured in this device is found less sensitive to the transconductance than that in the standard short channel MOSFET.