[amp_mcq option1=”Metal” option2=”Silicon-di-oxide” option3=”Polysilicon” option4=”Gallium” correct=”option3″]
The correct answer is C. Polysilicon.
A metal-oxide-semiconductor field-effect transistor (MOSFET), also known as an insulated-gate field-effect transistor (IGFET), is a type of transistor that uses a metal gate to control the flow of current between two semiconductor regions, known as the source and drain. The gate is insulated from the source and drain by a thin layer of silicon dioxide, which allows the MOSFET to be operated at high voltages without breaking down.
Polysilicon is a type of silicon that is used in the fabrication of MOSFETs. It is a thin film of silicon that is deposited on top of the semiconductor substrate. The polysilicon gate is then etched to form the desired pattern of gates.
The other options are incorrect because they are not used for the gate of MOSFETs. Metal is not used for the gate because it would conduct current and would not allow the MOSFET to be operated at high voltages. Silicon dioxide is used as the insulator between the gate and the source and drain regions. Gallium is not used in the fabrication of MOSFETs.