A metal-oxide-semiconductor field-effect transistor, with an insulating layer separating the gate from the semiconductor. Its gate electric field controls the channel's mobile charge carriers; a semiconductor inversion layer can form a two-dimensional electron gas.
An ideal insulating gate blocks particle exchange between the gate and substrate of a MOSFET. Their electrochemical potentials, represented by their band-diagram Fermi levels, therefore need not coincide. An applied gate voltage fixes their difference; with and voltage defined by an electron reservoir, . Contact work-function differences also affect band bending, so equal Fermi levels do not imply flat bands. Each conducting region can separately have a spatially constant equilibrium electrochemical potential.
An integrated circuit technology using complementary MOSFETs. CMOS names a circuit technology; active-pixel sensor names a detector architecture.
