metal insulator semiconductor field effect transistor (MOSFET) (MISFET)

MOSFETs come in different varieties such as the Metal Semiconductor Field Effect Transistor(MESFET), Metal Insulator Semiconductor Field Effect Transistor (MISFET), Junction Field-Effect Transistor( JFET) or Isulated Gate FET( IGFET).

In the MISFET, the source and drain are connected by a semiconductor, and the gate is metallic and separated from the other electrodes by an insulator. This structure is also called a high-k metal gate (HKMG) because the dielectrics have a higher permittivity than silicon dioxide( SiO2) and thus belong to the high-k dielectrics.

Applying a voltage to the gate changes the depletion region, causing more or fewer electrons to recombine with spurious electrons (holes). Depending on the control voltage, the conduction band of the band model may propagate more or less toward the valence band. Which results in the MISFET allowing a current flow to pass or blocking it.