Structure and Operation of MOSFET

Here we explain the operation of the MOSFET, referring to Fig. 3-6(a).
(1) Apply voltage between drain and source with positive drain polarity. (Drain-source voltage: VDS)
(2) Apply voltage between gate and source with positive gate polarity. (Gate-source voltage: VGS)
(3) As a result, electrons are attracted to the p-type layer just under the gate insulator film, and part of the p-type layer is turned into n-type region.(This n-type region in this p-type layer is called the "inversion layer (channel)".)
(4) As this inversion layer is completed, an n-layer path is formed from the drain to the source of the MOSFET.
 (n + ⇔ n - ⇔ inversion layer (n) ⇔ n +)
(5) As a result, the MOSFET works at low resistance, and drain current is determined by applied VDS and load flows.

Structure and operation of planar gate MOSFET / Structure and operation of trench gate MOSFET

Fig. 3-6(a) Structure and operation of planar gate MOSFET

Fig. 3-6(b) Structure and operation of trench gate MOSFET

Chapter III : Transistors

Types of Transistors
Bipolar Transistors (BJTs)
Bias Resistor Built-in Transistors (BRTs)
Junction Field-Effect Transistors (JFETs)
Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)
Differences between BJT and MOSFET
MOSFET Performance Improvement: Decision Factors of RDS(ON)
MOSFET Performance Improvement: Approach to Low RDS(ON)
MOSFET Performance Improvement: Super-Junction MOSFETs (SJ-MOS)
Summary of MOSFET Features by Structure
Performance of MOSFETs: Drain Current and Power Dissipation
Performance of MOSFETs: Avalanche Capability
Performance of MOSFETs: Characteristic of Capacitance
Performance of MOSFETs: Safe Operating Area(or Area of Safe Operation)
Insulated-Gate Bipolar Transistors (IGBTs)
Operation of Insulated-Gate Bipolar Transistors (IGBTs)
Performance Improvement of IGBTs: Evolution of Vertical Design
What are RC-IGBTs and IEGTs?
Application of IGBTs
Comparison of Forward Characteristics of IGBTs and MOSFETs
Comparison of Transistors by Structure
Datasheets of MOSFET: Maximum Ratings
Datasheets of MOSFET: Electrical Characteristics
Datasheets of MOSFET: Capacitance and Switching Characteristics
Datasheets of MOSFET: Body Diode

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