Enhancement/depletion surface channel field effect transistors of diamond and their logic circuits

Using the p-type surface-conductive layer of diamond film, enhancement mode and depletion mode metal-semiconductor field effect transistors were fabricated on the same surface by changing the metals of the gate electrode. The threshold voltages of p-type metal semiconductor field effect transistors (MESFETs) can be controlled from negative (enhancement mode) to positive (depletion mode) as the electronegativities of gate metals increase. By the realization of high transconductance and the fabrication of enhancement and depletion mode MESFETs, the E/D-type logic circuits such as inverter, NAND and NOR circuits were fabricated for the first time.