Metal oxide semiconductor refers to the physical stack of materials used to fabricate the gate region of a field-effect transistor. A conductive metal or polysilicon layer sits over a thin insulating silicon dioxide layer, which rests on a doped silicon substrate. Applying a voltage to the gate creates an electric field that controls current flow in the substrate beneath it.
The new fab line is optimized for advanced MOS processes, but we're still seeing unacceptable gate leakage.
While the 'M' stands for metal, polysilicon heavily replaced actual metal for the gate material in many historic and current fabrication processes.
Related terms
MOSFET
A metal-oxide-semiconductor field-effect transistor is a voltage-controlled switch used to amplify or switch electronic signals.
CMOS
Complementary metal-oxide-semiconductor is the dominant fabrication technology for integrated circuits.
pMOS
A field-effect transistor that uses positive charge carriers to conduct current.
nMOS
A type of field-effect transistor that uses negatively charged electrons as the primary charge carriers.