NOTES 27 March 2013 Chapter 10 MOSFETS CONTINUED
MOS Structure Under Reverse Bias 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) 12
Voltage-Current Relationship of NMOS (2) 13 Saturation region Nonsaturation region In the nonsaturation region: In the saturation region: Operation characteristics: No current through the gate oxide I G =0 Current in the channel is due to drift rather than diffusion Application: voltage controlled current source, analog switch
CMOS Technology 17 Complementary metal–oxide–semiconductor (CMOS)