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GaN and SiC may be made Obsolete by Gallium Oxide

November 19, 2014 by Jeff Shepard

Silvaco Japan Co., Ltd. has joined the cross-ministerial Strategic Innovation Promotion (SIP) program next generation power electronics project "Research and Development on Fundamental Technologies of Gallium Oxide Power Devices" promoted by New Energy and Industrial Technology Development Organization (NEDO). Other participants in this project include: National Institute of Information and Communication Technology, Tamura Corporation, Tokyo University of Agriculture and Technology and New Japan Radio Co., Ltd. The consortium believes that gallium oxide (Ga2O3) will be even more competitive than SiC and GaN for power devices because of its wider bandgap and other superior material properties and lower cost.

Tamura currently offers commercial Ga2O3 substrates. According to Tamura, Ga2O3 transistors are less lossy (i.e. more energy-efficient) than Si and SiC transistors at a given breakdown voltage by about 3,000- and about 10-times, respectively. The reduction in power loss corresponds directly to the amount of energy saved. Therefore, Ga2O3 has better characteristics as a power device material than not only Si but also SiC and GaN.

The melt-growth method being used to produce Ga2O3 is a low-energy-consumption, low-cost way of making large substrates because it does not require a high-temperature and/or high-pressure environment and uses less source material. As the substrate production cost accounts for a large percentage (~60%) of the total production cost of widegap power devices (SiC, GaN, and diamond) for which a melt-grown substrate technology is unavailable, the ability to mass-produce large area single-crystal substrates from a melt is a huge cost advantage of Ga2O3 over other widegap semiconductors. Tamura anticipates that a large Ga2O3 substrate (over 6~8 inches in diameter) could cost 10- to 100-times less than SiC and GaN substrates.

The National Institute of Information and Communication Technology, Tamura and KOHA Co., Ltd., successfully developed the world’s first MOSFET using gallium oxide. To promote gallium oxide as the next generation power device material, this project included research and development ranging from the basic physical properties to the technologies for future industrial applications, such as bulk and thin-film crystal growth technology, device process technology and module technology. The target of this project is to establish the fundamental technologies for gallium oxide power devices by fiscal year 2018.

Transistors and diodes with gallium oxide are expected to have the advantage in power device characteristics, such as higher breakdown voltage, higher output and lower dissipation compared to traditional compound semiconductor devices. Moreover, it is theoretically possible with ß-Ga2O3 to create large diameter single crystalline substrates by melt growth method, at low energy and for a low cost, enabling production of bulk single crystal. These characteristics may have significant advantages for industrial applications.

Iliya Pesic, President of Silvaco Japan said, "Silvaco has many years of experience in the development, sales and technical support of semiconductor process and device simulators. Silvaco has key advantages in simulation technology for silicon and compound semiconductor power devices. Silvaco’s leading edge technologies with proven performance in wide band gap semiconductors will enable it to make a significant contribution to the project."