Performance Improvement of IGBTs: Evolution of Vertical Design

As shown in Fig. 3-15 (a), the vertical design of the IGBT has been evolving.
Starting from the PT structure, thin PT (generally called “Field Stop”) structure is becoming mainstream as thin wafers are now used. (Gate structure is the same as MOSFET.)

Transition of IGBT’s vertical design
Fig. 3-15(a) Transition of IGBT’s vertical design

VCE(sat) characteristic of PT type has a current value (called “Q point”) that crosses at high temperature and at room temperature.
Since the high-temperature VCE(sat) is always high in the NPT type (like MOSFET), it is easier to balance the collector current even when operating in parallel.

Difference of forward characteristic between PT type and NPT type
Fig. 3-15(b) Difference of forward characteristic between PT type and NPT type

Note: VCE(sat)characteristic - voltage drop when collector current flows in forward direction.

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
Structure and Operation of 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)
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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