Replacement metal gate
Beginner
Building a stand-in gate first, then swapping it for the real metal gate near the end, so the real gate isn’t damaged by the hot early steps.
Novice
A process in which a sacrificial ‘dummy’ gate defines where the gate goes during the hot source/drain steps, then is removed and replaced by the high-k insulator and metal gate. In nanosheet transistors the swap is also when the sheets are released and wrapped.
Expert
Gate-last HKMG flow. In GAA the dummy-gate removal opens the way for channel release, and the interfacial oxide, high-k and work-function metals are then deposited conformally by ALD into the gaps between sheets, only a few nanometers wide.
Explained in Fins and nanosheets (Transistors).
See also: Channel release, High-k/metal gate (HKMG).