Structure and Operation of the MOSFET 9 and 11 March 2015 FET Circa 1964-Commercial Introduction First FET IC Circa 1964 By RCA MOS Inversion Layer Metal layer Oxide layer P-type n-type inversion layer With large positive gate bias, there will be electrons at the interface between the oxide and semiconductor, which leads to formation of a thin n-type inversion layer Threshold voltage V T : applied gate voltage required to achieve the threshold inversion Voltage-Current Relationship of NMOS (1) 13 Voltage-Current Relationship of NMOS (1) 20