Download SiC Power Devices

SiC Power Devices
Vaibhav Ostwal
3-29-2017
Power Electronics Application and Desired
Material Properties
Ref. :IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014
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:
Ref.: IET Circuits Devices Syst., 2014, Vol. 8, Iss. 3, pp. 227–236
 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
SiC Devices Progress
Ref.: TIE.2017.2652401, IEEE Transactions on Industrial Electronics
SiC Power Rectifier
Schottky Barrier Diode
(SBD)
Low turn-on voltage
junction barrier
Schottky (JBS) diode
P-I-N diode
SBD and JBS
Turn-on voltage = 3V
PIN
diode
•
• high switching speed and low •
on-state losses
• lower blocking voltage and high
leakage current
High reverse
biased current
during ON to
OFF transition
Introducing p+ islands in this
• high-voltage operation and low
structure additionally shields the
leakage current
electric field from the Schottky • reverse recovery charging
contact thus reducing the
during switching: Low speed
leakage currents
Ref. :IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014
1200 V thinQ!™ SiC Diode Generation 5
design – Infineon Technologies
• Merged-Pin-Schottky
(MPS)
PIN
MPS
SBD
Ref.: www.infineon.com
SiC P-I-N Diode: future smart grids and highvoltage 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
SiC Power Switching Devices
Vertical SiC Devices
SiC MOSFET Technology
• Operational voltage
range: 600 V- 5 kV
DMOSFET
(Double-implanted)
SiC IGBT Technology
• Over 5 kV voltage
range SiC IGBT is
more attractive
UMOSFET
Ref. :IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014
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
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)
ROHM:
• VGS-on = 18 V
Ref.: http://www.rohm.co.jp
rd
3
Generation SiC MOSFET
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 !