What are wide band gap semiconductors?

Semiconductor material physical property comparison

Unit Si

4H-SiC

GaN

Ga2O3

Diamond
Band gap

eV

1.12

3.26

3.39

4.8

5.47

Electron mobility

㎠/Vs

1.12

1000

900

300

2200

Insulation breakdown field intensity

MV/㎝

0.3

2.5

3.3

8

10

Thermal conductivity

W/㎝K

1.5

4.9

2

4.8

20

BM*

-

1

340

650

3400 27000
Technology level -

Mass
production

Partial mass
production

Partial mass
production

Research
stage
Research
stage

*Baliga's Figure of merit - The larger this value, the higher the potential for lowering the drift layer resistance.

Using a large material for the band gap makes it possible to achieve high insulation breakdown field intensity. Specifically, this means that it is possible to generate a high voltage in a thin depletion layer, so the drift layer can be made thinner and the impurity concentration can be increased, the synergistic benefits of which create the potential to significantly improve the tradeoff between withstand voltage and drift resistance. A figure of merit of 340 SiC, indicates that drift resistance can be reduced to 1/340th using the given material.

Comparison of theoretical limits by semiconductor materials

Wide band gap semiconductors are semiconductor materials which can greatly reduce ON resistance.

Power device application fields

SiC contributes to higher withstand voltage and higher power, while GaN contributes to higher frequency usage, both of which expand the application fields for power devices.

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