Types of MOSFET

Introduction

AU : May-13, Marks 2

• MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is a second category of field effect transistor. The MOSFETs, compared to BJTs, can be made very small and hence can be used to design high density VLSI circuits.

• The MOSFET has no pn junction structure; instead, the gate of the MOSFET is insulated from the channel by a silicon dioxide (SiO₂) layer. Due to this the input resistance of MOSFET is very high.

• Because of the insulated gate, MOSFETs are also called IGFETs. The two basic types of MOSFETs are : depletion (D) MOSFET and enhancement (E) MOSFET.

Review Question

1. What is MOSFET ? Name its types.