An important goal of the program is to lower GaN technology cost by using large-diameter GaN-on-Si and hence by leveraging on the Si scale of economics.
The scope of the IIAP is to develop high-voltage, low-loss, high-power switching devices based on large-diameter (up to 200mm) 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 today on the market are based on AlGaN/GaN high-electron mobility transistor (HEMT) structures and are normally-on devices, designed for RF applications, e.g. 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 (600-1000V) and low on-resistance, operating in enhancement mode.
A second sub-program 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 ultraviolet (UV) spectrum. However, LED illumination by these devices can only become broadly acceptable if new volume manufacturing technologies are developed that enable 150lm/W LEDs.
Common challenge for power electronics and optoelectronics is cost reduction. “GaN on large-diameter Si wafers (from 100mm and 150mm towards 200mm) 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 shown in collaboration with AIXTRON crack-free GaN growth on 200mm 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 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.