IMEC (Leuven, Belgium) announced the launch of a new industrial affiliation program (IIAP) that will focus on the development of gallium nitride (GaN)-based technology for both power conversion and solid-state-lighting applications. An important goal of the program is to lower GaN technology cost by using large-diameter GaN-on-silicon (Si) and hence by leveraging the Si scale of economics. The announcement was made at Semicon West 2009 (July 14 to 16; San Francisco, CA).
The scope of the IIAP is to develop high-voltage, low-loss, high-power switching devices based on large-diameter (up to 200 mm) GaN-on-Si technology. Potential applications include high-power switching in solar converters, motor drives, hybrid electrical vehicles, or switch-mode power supplies.
High-voltage power devices are traditionally based on Si MOSFET structures. However, for a number of applications, they are reaching intrinsic material limits. GaN-based devices can overcome these limits due to a unique combination of excellent transport properties and high-electrical-field-operation capability. The few GaN devices of this sort that are on the market today are based on AlGaN/GaN high-electron mobility transistor (HEMT) structures and are normally-on devices, designed for RF applications, for example in wireless communication. Within the IIAP, the next-generation of power electronics components is envisaged, requiring the development of normally-off devices (for safety reasons) with high-voltage breakdown (600-1000 V) and low on-resistance, operating in enhancement mode.
White-light LEDs: aiming for 150 lm/W
A second subprogram will exploit GaN-on-Si technology for the development of high-efficiency high-power white LEDs. Key issues are enhancing the external and internal quantum efficiencies and enabling high-current-operation. III-nitrides in general exhibit excellent light emission properties in a very broad range of the visible and UV spectrum. However, LED illumination by these devices can only become broadly acceptable if new volume manufacturing technologies are developed that enable 150 lm/W LEDs.
A common challenge for power electronics and optoelectronics is cost reduction. "GaN on large-diameter Si wafers (from 100 mm and 150 mm towards 200 mm) in combination with CMOS-compatible processes offers the best perspective to create economically viable solutions," said Marianne Germain, GaN program director. "While very few players can today process GaN on large-diameter Si wafers, IMEC has recently, in collaboration with AIXTRON (Hertzogenrath, Germany), shown crack-free GaN growth on 200 mm wafers. Also for other challenges, the IIAP can build on IMEC's 10 years' experience in GaN technology, including unique skills in epi-layer growth, new device concept, device integration, and a thin-film textured LED technology for high-efficiency III-nitride LEDs."
IMEC invites both integrated-device manufacturers and those in the compound semiconductor industry to join the program, where they can build on IMEC's extensive expertise in GaN and benefit from a sharing of cost, risk, talent, and IP, according to IMEC.
