Physical Structure -4 MOS transistor Symbols: NMOS PMOS NMOS PMOS NMOS PMOS D D D Go- …0B (a) (b) (e】 。In NMOS Devices:Source-cleciron→Drain Current flows from Drain to Source ·In PMOS Devices:Source-_hoe→Drain Current flows from Source to Drain 。 Current flow determines which terminal is Source and which one is Drain.Equivalently,source and drain can be determined based on their relative voltages. 西/2020/3/7 7 SM 16 EECE 488 ± Set 1: Introduction and Background Physical Structure - 4 ‡ MOS transistor Symbols: ‡ In NMOS Devices: Current flows from Drain to Source ‡ In PMOS Devices: Current flows from Source to Drain ‡ Current flow determines which terminal is Source and which one is Drain. Equivalently, source and drain can be determined based on their relative voltages. Source Drain electron o Source Drain hole o