Plenary Session
-
Title: Wide
Bandgap Semiconductor Electronics – from DC
to Light!
Presented by: Dr. John W. Palmour Abstract Bio
Wide Bandgap Semiconductor Electronics – from DC to Light!
Abstract: The wide bandgap semiconductors,
Silicon Carbide (SiC) and Gallium Nitride (GaN), have emerged
over the last 15 years to show superior performance for a
variety of applications with frequencies from DC to light. The
largest market by far today is that of blue, green, and white
LEDs, based on GaN. These devices have become ubiquitous in the
areas of backlighting LCD screens, signage, large format full
color displays, and most recently for highly efficient solid
state lighting to replace incandescent and fluorescent lamps.
For RF applications, GaN grown on SiC substrates is rapidly
emerging as the semiconductor of choice for high power
amplifiers, allowing unprecedented power-bandwidth products for
a variety of military applications, and more recently for
commercial telecom. applications such as LTE. GaN HEMT based
circuits are also being used for low noise amplifiers,
multi-throw switches, mixers and oscillators both in hybrid and
MMIC forms. For lower frequency power switching applications,
SiC Schottky diodes have become very prevalent in switch mode
power supplies and in solar inverters because of the increased
efficiency that they can offer. More recently SiC power switches
such as MOSFETs have come on the market, which will allow even
further improvements in power conversion efficiencies for
applications from 600 V all the way up to 15 kV. The use of GaN
as a power device has attracted a tremendous amount of attention
recently for its high speed, high efficiency capabilities at
voltages from 30V up to 1200V.
The physical reasons why these wide bandgap semiconductors allow
these improvements across such a wide range of frequencies will
be detailed, and the relative merits of GaN and SiC, or the
combination of both, will be discussed.
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Dr. John W. Palmour,
Chief Technology Officer – Power & RF, directs and conducts all
Power device and Microwave device developments at Cree, Inc. He
was one of the co-founders of Cree in 1987, and served on the
Board of Directors for the company from 1995 to 2010. Dr.
Palmour has been a leader in SiC and GaN device development for
the last 25 years, and has demonstrated numerous firsts in these
technology areas. He has been responsible for the development of
high frequency GaN HEMTs and MMICs, as well as high voltage,
high temperature 4H-SiC power diodes and transistors. He also
manages the Company’s government contract research programs.
During his career, he has authored or co-authored more than 266
publications and is a co-inventor on 46 U.S. patents and 135
corresponding foreign patents. Dr. Palmour received his B.S. and
Ph.D. degrees from North Carolina State University, Raleigh, in
1982 and 1988, respectively, where his major was in Materials
Science and Engineering.
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