1. SiC Power Devices
Vaibhav Ostwal

2. Power Electronics Application and Desired Material Properties
Ref. :IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014

3. WBG Materials Advantages of GaN and SiC among WBG:
Matured technological processes
Commercial availability of starting material i.e wafers and epitaxial layers
GaN has better ON resistance
Advantages of SiC over GaN:
Higher thermal conductivity
Availability of good quality bulk substrate (100-mm SiC wafers are in the market)
Recent progress in Micro-pipe free material and screw & basal plane dislocations
Ref.: IET Circuits Devices Syst., 2014, Vol. 8, Iss. 3, pp. 227–236

4. SiC Devices Progress
Ref.: TIE , IEEE Transactions on Industrial Electronics

5. SiC Power Rectifier Schottky Barrier Diode (SBD)
junction barrier Schottky (JBS) diode
P-I-N diode
SBD and JBS
Low turn-on voltage
Turn-on voltage = 3V
PIN diode
High reverse biased current during ON to OFF transition
high switching speed and low on-state losses
lower blocking voltage and high leakage current
Introducing p+ islands in this structure additionally shields the electric field from the Schottky contact thus reducing the leakage currents
high-voltage operation and low leakage current
reverse recovery charging during switching: Low speed
Ref. :IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014

6. 1200 V thinQ!™ SiC Diode Generation 5 design – Infineon Technologies
Merged-Pin-Schottky (MPS)
PIN
MPS
SBD
Ref.:

7. SiC P-I-N Diode: future smart grids and high-voltage power supplies
Acceptor level of a carbon monovacancy was eliminated using thermal oxidation to enhance lifetime and achieve low differential on resistance
Ref.: IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 62, NO. 2, FEBRUARY 2015

8. SiC Power Switching Devices
Vertical SiC Devices
SiC MOSFET Technology
Operational voltage range: 600 V- 5 kV
SiC IGBT Technology
Over 5 kV voltage range SiC IGBT is more attractive
DMOSFET
(Double-implanted)
UMOSFET
Ref. :IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014

9. UMOSFET ISSUE: Field Crowding at the trench corner
Solution: P-trench implant
Ref.: IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 49, NO. 6, JUNE 2002
Using P-type trench implant
ISSUE: Adding P+ trench implant creates RJFET

10. SiC Power Switch STEP TRENCH DEVICE Other progress in SiC MOSFETS:
The highest blocking voltage of 15 kV was reported for SiC MOSFET
(ref. : Proc. IEEE ECCE, 2014, pp. 449–454)
Reliability of industry-leading 200°C-rated SiC MOSFET was reported by GE in 2014
(ref. : Proc. Int. Symp. Power Semicond. Devices ICs, 2014, pp. 297–300)

11. ROHM: 3rd Generation SiC MOSFET
VGS-on = 18 V
Ref.:

12. SiC Power Devices: Challenges
Low electron mobility in the inversion channel layer: eliminate the SiC/SiO2 interface defects
Gate oxide reliability with high temperature or high electric field
Thermal management strategies: new package materials for high temperature application
THANK YOU !