The IGBT Structure
The silicon cross-section of an Insulated Gate Bipolar Transistor (IGBT), the
terminal called Collector is, actually, the Emitter of the PNP. In spite of its
similarity to the cross-section of a power MOSFET, operating of the two
transistors is fundamentally different, the IGBT being a minority carrier device.
Except for the P + substrate is virtually identical to that of a power MOSFET,
both devices share a similar polysilicon gate structure and P wells with N +
source contacts. In both devices the N-type material under the P wells is sized
in thickness and reistivity to sustain the full voltage rating of the device.
However, in spite of the many similarities, he physical operation of the IGBT is
closer to that of a bipolar transistor than to that of a power MOSFET. This is
due to the P + substrate which is responsible for the minority carrier injection
into the N regtion and the resulting conductivity modulation, a significant share
of the conduction losses occur in the N region, typically 70% in a 500v device.
The part number itself contains in coded form the key features of the IGBT. An
explanation of the nomenclature in contained below.
IR
G
4
B
C
4
0
S
D
Diode
International Rectifier
IGBT
Generation
Package Designator
B T0220
P T0247
Voltage Designator
C 600v E 800v
F 900v G 1000v
H 1200v
Speed Designator
S Standard
Modifier
F Fast
Die Size
M Short Cicuit Fast
U UltraFast
K Short Circuit UltraFast
Basic IGBT Structure
IGBT / CoPack
Quarterly Reliability Report
Page 7 of 35
IRF [ INTERNATIONAL RECTIFIER ]
