Wide Bandgap Devices
Enabling a Revolution in Power Electronics
Dr. Anant Agarwal
Senior Advisor, Wide Band Gap Technology
US Department of Energy
History of Collaboration and Investment
Hard Work and Effort
Industry Participation
Partnerships
What are Wide Band Gap (WBG) Semiconductors?
Property
Si
4H-SiC
GaN
Diamond
Bandgap Eg, (eV)
1.12
3.26
3.45
5.45
Dielectric constant, εr
11.9
10.1
9
5.5
Electric breakdown field, Ec (kV/cm)
300
2,200
2,000
10,000
1,500
1,000
1,250
2,200
Hole Mobility, μp (cm2/V·s)
600
115
850
850
Thermal Conductivity, λ (W/cm·K)
1.5
4.9
1.3
22
1
2
2.2
2.7
Electron Mobility, μn (cm2/V·s)
Saturated Electron Drift Velocity,
vsat (×107cm/s)
Enables
Higher Temperature
Higher Voltage
Higher Frequency
More Efficient,
Smaller, Cheaper
Power Electronics
SiC and GaN: Each have Unique Capabilities
• GaN based Power Electronics:
– Suitable from 200 to 900 V
– Ideal applications:
– 0.1 to 10 kW Power Supplies
– Laptop power adapters
– Micro and string solar inverters up to 10 kW
• SiC based Power Electronics:
– Suitable from 900 to 15,000 V
– Ideal applications:
–
–
–
–
–
String solar inverters >10 kW
Central Solar and Fuel Cell Inverters up to several MW
Automotive Inverters and Quick Chargers
Traction
Medium Voltage Motor Control for Oil and NG high rpm direct
drive
– Distribution Grid Based Power Flow Controllers
Barriers to Acceptance
• High Cost of WBG Chips
‒ Lower systems cost--arguments don’t work
‒ Must establish a more compelling value
proposition for market acceptance
• PE Community slow to change and adapt new
technologies
‒ Lack of experience with WBG semiconductors
‒ Perceptions of poor reliability
• Development efforts lagging in high
temperature, high frequency packaging to
capitalize on device benefits
Pow
Meeting the Challenges
Implement Commercial Foundry Model
• Exploit capital cost of manufacturing equipment, idle time
and overhead costs in existing, dedicated foundries
• Aggregate production volumes to better negotiate substrate
and epi costs from vendors
Accelerate Market Share
• Develop power modules that make WBG devices ‘shine’
• Initiate PE Demonstration Projects to validate superior
performance and reliability
• Accelerate educational opportunities and training to
promote WBG use following graduation
Goal: WBG cost comparable to today’s silicon cost in 5 yrs
Benefits of Using Commercial Si Foundry
DoD
6” SiC
6” GaN
• Typically only 10-20% capacity of
Universities
commercial foundry utilized
– 90% of the processes are the same
Loaded US
based 6” Si
Foundry
National
Labs
Small and Large Industry
• Reduce substrate and manufacturing costs by aggregating demand
for 150 mm SiC wafers
• Robust and reproducible manufacturing- process recipes on proven
equipment
• Innovation by researchers, small companies and students through
design and access to fabless model—similar to MOSIS
• Reduce technology risk…encourage investments by VC firms
‒ $10-15 M is required to create a product as opposed to $100 M
Reducing Cost of Wide Band Gap Power Devices
Low Voltage
Devices
(600V to 1700V)
3 years
Medium Voltage
Devices
(3300V to 6500V)
5 years
High Voltage
Devices
(> 10kV)
10 years
1.5X
TARGET:
WBG Costs
Reach Parity with Silicon
Cost Parity
Overcoming Reticence to Adoption
Education and Training
• Establish programs at different educational levels in:
‒ WBG technology
‒ PE applications with WBG devices
• Grow experienced workforce
• Generate future leaders in power electronics
• Develop text book on design and processing of WBG
power devices
‒ Equivalent to Mead & Conway - 1979
Goal: Train at least 100 Graduate students in 5 years
How WBG Can Manifest Change (1)
1200 V SIC MOSFETS
Toyota Now
Prototype
Volume
387.5 in3
42 in3
Mass
6.6 kg
0.99 kg
Power
1 kW
5 kW*
Efficiency
<90%
>96%*
Present Toyota
Si PHEV Charger
(1 kW)
SiC PHEV
Charger (5 kW)
More Efficient Transportation Alternatives
How WBG Can Manifest Change (2)
Sales volume of GaN lateral Transistors will Increase and Costs will
Decrease….
• AC Power Adapters:
laptops, cell phones, tablets, printers, appliances…
65 W
0.5 W/cm3
Peak Efficiency: 85-90%
5 W/cm3
Peak Efficiency: 93%
More desirable smaller and lighter consumer products
will propel market
WBG Power Semiconductor Roadmap
• Reduce chip costs 50% every 2 years with improved
performance
‒ Achieve WBG cost parity with Si in 5 years
‒ Reduce WBG cost below today’s silicon price in 5-8 years
‒ Manufacturing 8-inch wafers in 5-8 years
• WBG devices replacing 600V-1700 V Si in mainstream
applications within 5 years
• Development of 10-15 kV devices enabling new applications
in MV motor and Grid Power Control
The market for WBG devices will double every 2 years from
$100M to $3B in 10 years
New Systems, enabled by WBG, will create $20B in new global
markets