Introduction to the Focus Issue on Wide Bandgap Power Semiconductors

Abstract

Wide bandgap (WBG) semiconductors, especially Silicon Carbide (SiC) and Gallium Nitride (GaN), offer unprecedented opportunities for transformative changes in electric utility and transportation infrastructures. Compared to semiconductor silicon, SiC and GaN offer significantly higher electrical and thermal conductivities, increased avalanche breakdown field strength, and improved ruggedness under extreme environmental operating conditions. These basic material properties translate into more compact and lightweight energy conversion systems with significant energy savings, much improved signal sensing and transmission characteristics, and longer operating lifetimes in the field. Commercial products that are poised to significantly benefit from SiC and GaN semiconductors include solid-state energy converters, power management electronics, power amplifiers, light-emitting diodes (LEDs), solar cells, lasers, and environmental sensors. The current global annual market potential for these products is collectively in excess of $100 billion. The potential annual market size for WBG power semiconductor devices alone now exceeds $30billionwithexponentialgrowthexpectedinthenextdecade.However, state-of-the-art commercial WBG power devices have limited voltage and current ratings, unproven field-reliability, and are prohibitively expensive. Consequently, the current global sales of WBG power devices is about $200 million per year. Realizing the current technology status and the vast commercial potential of WBG power semiconductor devices, an annual ECS Symposium on GaN and SiC Power Technologies was established in 2011. The2013Symposiumispoisedtobeveryexcitingandwillincludeoral presentations of more than 60 high-quality technical papers and two evening panel sessions involving in-depth discussion of topics ranging from materials to end-applications, and their inter-relationships, in order to understand and address the critical issues that are hindering rapid commercialization of WBG power technologies. Thisfocusissueincludesatotalof18full-lengthpeer-reviewedpapers. The focus issue begins with an overview paper that summarizes the current status and emerging trends in WBG power semiconductor devices from application considerations; the imminent need to reduce crystal defects in both bulk substrates and epitaxial layers is the highlight of this paper. There are a total of eight papers on SiC material technology.MorespecificallyonepaperonSiCbulksubstrategrowth, five papers on SiC homoepitaxy, one paper on SiC surface modification, and one paper on SiC material characterization. In addition, two papers on bulk GaN crystal growth and one paper on GaN-on-Si epitaxy are included. One paper deals with SiC and GaN wafer planarization,animportantprocessingtechniquepriortomaterialgrowth ∗ Electrochemical Society Active Member.