imec performs world-leading research in nanoelectronics, delivering industry-relevant technology solutions through its global partnerships in ICT, healthcare and energy. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society.

imec, founded in 1984, performs world-leading research in nanoelectronics and nanotechnology. It leverages its scientific knowledge and delivers industry-relevant technology solutions with the innovative power of its global partnerships in ICT, healthcare and energy. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society. Imec is headquartered in Leuven, Belgium, and has offices in Belgium, the Netherlands (so called Holst Centre in collaboration with TNO), Taiwan, US, China, India and Japan. Their staff of over 2,080 people includes more than 670 industrial residents and guest researchers. In 2012, 133 patents were filed and published 1,064 peer reviewed papers. 34 prizes were awarded to Imec’s researchers for their research, and 161 patents were awarded. Currently, imec collaborates with over 600 companies and 200 universities worldwide. Since its start, 36 spinoff companies were launched. In 2012, the ISO9001 quality certification was successfully renewed; this is a cornerstone for our operational excellence.

Role:

imec is leading the activities related to research and development of next generation substrates and isolation techniques for 200mm. In the respect, imec will be in charge of coordinating the activities of WP1, which encapsulates all these activities. Furthermore, imec will contribute to reliability testing and evaluation of the novel substrates in WP6.

Key Contribution:

While SiC substrates are often preferred for easier thermal management, Si substrates have become very attractive for GaN growth because of their larger wafer diameter (200mm and higher) and lower costs perspectives. The growth of GaN on Si is however very challenging and is seen as a possible stumbling block for further improving on the current generation of GaN-based power devices. The lattice mismatch between Si and GaN and the thermal expansion mismatch during growth or cool down can lead to film cracking or wafer bowing, and can generate a high density of defects. The wafer bow also increases with increasing wafer sizes which makes up-scaling difficult.

Within the PowerBase project, imec will therefore look into new substrate approaches that provide a better (Al)GaN crystal quality and lower wafer bow.  Novel substrates (such as AlN and Mo substrates) as well as alternative growth techniques will be explored. The target diameter for the advanced substrates is 200mm, and their compatibility with the pilot line activities within the PowerBase project will be assessed.

imec will also look into alternative techniques for the electrical isolation in GaN-on-Si power devices. Today, isolation in GaN-on-Si devices comprises of lateral and vertical isolation, with typically a connection from the source terminal to the substrate. This connection, however hinders the co-integration of high side and low side switches on a single chip. Therefore, imec will look into alternative isolation modules that allow isolating different devices on-chip and which can increase the level of integration.

Contact

	imec
Kapeldreef 75
3001 Heverlee, Belgium
www.imec.be