nMOS stands for n-type metal-oxide-semiconductor, referring to a transistor built with electron-rich source and drain regions on a p-type substrate. When a positive voltage is applied to the gate, it creates a conductive channel of electrons, turning the device on. Because electrons move faster than holes, these transistors switch much faster than their p-type counterparts.
The pull-down network in this logic gate is built entirely out of nMOS transistors to handle the fast switching.
Related terms
pMOS
A field-effect transistor that uses positive charge carriers to conduct current.
CMOS
Complementary metal-oxide-semiconductor is the dominant fabrication technology for integrated circuits.
MOSFET
A metal-oxide-semiconductor field-effect transistor is a voltage-controlled switch used to amplify or switch electronic signals.
nMOSFET
An nMOSFET is a transistor that uses a positive gate voltage to create an electron-conducting channel.