Wide Bandgap Semiconductor Technology Research Articles

THE PERFECT POWER SEMICONDUCTOR SWITCH FOR 21st CENTURY GLOBAL ENERGY ECONOMY

A critical evaluation of high-power electronics switching in semiconductor materials is made from the standpoint of performance, reliability, and commercial viability. This study takes into account recent experimental results obtained from the field-reliability study of silicon power MOSFETs in high-density power supplies where residual material defects present in the space charge region of the device were found to generate local micro plasma that eventually caused power MOSFETs to fail. Based on these results and commercial progress made to date in wide bandgap semiconductor technologies, it is suggested that silicon carbide (SiC) promises to be the preferred material for high-power electronics switching from cost, performance and reliability considerations — this assessment is further strengthened by the near-term potential for developing large-area, low-cost, and defect-free SiC bulk substrates and epitaxial layers. This conclusion is also supported by the feasibility and the need for vertical, MOS-controlled, bipolar power switches in compact and efficient megaWatt-level power converters in order to make transformational changes in the 21st century electrical transmission and distribution infrastructure.

Wide-Bandgap Semiconductor Technology: Its impact on the electrification of the transportation industry

The efficiency of any electric vehicle (EV) is limited by the efficiency of its power electronic motor drive. Currently, EVs use conventional silicon (Si) insulated-gate bipolar transistor (IGBT) or Si metal?oxide?semiconductor field-effect transistor (MOSFET) technologies. Si technology prevents traction motor drives from exceeding the low switching frequencies (tens of kilohertz) due to excessive switching losses. This is important as the size of passive components (and thus cost) is inversely related to the switching frequency.

Preface: Phys. Status Solidi A 206/2

The Seventh International Symposium on Semiconductor Light Emitting Devices (ISSLED 2008) was held in Phoenix, Arizona, on the week of 27 April to 2 May 2008. This Symposium is a new edition of the International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED) series which has been held biannually to provide a platform for scientists and engineers to discuss progress and future trends in the rapidly advancing wide band gap semiconductor science and technologies and their applications into visible and ultraviolet light emitting diodes and diode lasers. The first symposium in the series was organized by Prof. Akihiko Yoshikawa and was held in Chiba, Japan, in 1996. The following symposia were held in Chiba, Japan, in 1998; Berlin, Germany, in 2000; Cordoba, Spain, in 2002; Geongju, Korea, in 2004; and more recently in Montpellier, France, in 2006. The participants were 33 from Asia (16 from Japan), 19 from Europe, and 66 from North America. The ISSLED 2008 scientific program included a total of 14 invited talks and 63 contributed talks. This symposium covered materials and their devices based on GaN, ZnSe, and ZnO semiconductors. The topics included materials growth and characterization, optoelectronic properties, device design and fabrication, white light emitting diodes, ultraviolet emitters and detectors, photonics, device performance and reliability, novel optoelectronic devices and applications, spintronics, and biological applications. The next meeting in this series was proposed, and accepted by the International Advisory Committee, to be held in China, in May 2010, to be organized by Prof. Guoyi Zhang of Peking University (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Wet Chemical Etching of Wide Bandgap Semiconductors- GaN, ZnO and SiC

Wide bandgap semiconductors have many properties that make them attractive for high power, high temperature device applications. In this paper we review wet etching of three important materials, namely ZnO, GaN and SiC. While ZnO is readily etched in many acid solutions including HNO3/HCl and HF/HNO3, and in the nonacid acetyleacetone, the group III nitrides and SiC are very difficult to wet etch and generally dry etching is used. Various etchants for GaN and SiC have been investigated, including aqueous mineral acid and base solutions, and molten salts. Wet etches have a variety of applications to wide bandgap semiconductor technology, including defect decoration, polarity and polytype (for SiC) identification by producing characteristic pits or hillocks, and device fabrication on smooth surfaces. Electrochemical etching is successful at room temperature in some situations for GaN and SiC. In addition, photo-assisted wet etching produces similar rates independent of crystal polarity.

Proceedings of the 5th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED‐2004)

The 5th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED-2004) was held in Gyeongju, Korea, 15–19 March 2004. The purpose of the symposium was to provide a forum for scientists and engineers to discuss recent progress and future trends in the rapidly advancing wide band gap semiconductor science and technologies and their applications in blue laser and light emitting diodes.

Challenges and potential payoff for crystalline oxides in wide bandgap semiconductor technology

While growth of wide bandgap semiconductor materials on crystalline oxides (sapphire, lithium gallate, lithium aluminate, zinc oxide and others) has become routine, growth of crystalline oxides on wide bandgap materials remains challenging and minimally explored. The potential payoff in terms of enhanced device performance, increased functionality and reliability warrants examining this option. This presentation aims at targeting key areas, where crystalline oxides could improve wide bandgap semiconductor device performance. Some of these include the use of ferroelectric oxides for power switching applications, oxides with anisotropic dielectric constants for high voltage termination and oxides with large electric flux density near breakdown. Unique polarization engineered structures are described that are enabled by using lithographically defined poled regions in a ferroelectric substrate. The desired crystalline oxide properties, potential implementation challenges and potential pitfalls will be discussed.