Roger Loo
Roger Loo
imec
Date: May 6, 2026
Time: 1000–1100h ET
The evolution of metal-oxide-semiconductor device architectures and the corresponding requirements on epitaxial growth schemes is described. A discussion follows of the obtained material properties of Si/SiGe multilayer stacks used for logic and 3D DRAM devices, grown on 300 mm Si(001) wafers.
(Click to enlarge)
The process used to deposit Si/SiGe multilayers for Nano-Sheet devices has been extended to 120 pairs (241 sub-layers) of {65 nm Si/10 nm strained Si0.8Ge0.2} for 3D DRAM concepts [1]. A more complicated layer stack with two different Ge concentrations is required for the monolithic fabrication of complementary field effect transistor (CFET) devices, where gate-all-around nFETs and pFETs are stacked on top of each other [2]. A relatively high growth temperature provides acceptable Si and SiGe growth rates while still suppressing 3D island growth for SiGe growth with up to 40 percent Ge. Excellent structural and optical material properties of the epi stack are reported, with up to 3 + 3 Si channels in the top and bottom part of the stack, respectively. For all layer designs, the absence/presence of lattice defects has been verified by several techniques including photoluminescence (PL) measurements at both room-temperature and low temperature.
[1] R. Loo et al., JAP 138, 055702 (2025), https://doi.org/10.1063/5.0260979
[2] R. Loo et al., ECS SST 14, 015003 (2025), https://iopscience.iop.org/article/10.1149/2162-8777/ada79f
Attend this webinar to learn about:
- Epitaxial growth requirements in view of novel device applications
- Material characterization
- Introduction to imec’s NanoIC program activities
Presenter
Dr. Roger Loo is a Principal Scientist (Principal Member of Technical Staff) in the group IV epi team at imec. He received his PhD from the Rheinisch-Westfälische Technische Hochschule Aachen in 1997, joined imec that year, and was promoted to his current position in 2013. In 2023, he was also named Visiting Professor at Universiteit Gent. Dr. Loo authored or co-authored > 240 articles in peer-reviewed journals. He coedited eight journal special issues; (co-) authored > 250 articles in proceedings listed in the ISI Web of Science; and presented > 30 invited talks at international conferences. Dr. Loo coauthored > 90 patent filings (including provisional filings), of which over 50 patents have been granted and are maintained. On a regular basis, he gives invited research seminars/tutorials at universities, institutes, and companies. He has also (co-) organized about 24 international conferences.
Thanks to the webinar sponsors who make these complimentary programs possible!
 |
 |
Interested in presenting in the ECS Webinar Series? Email your presentation title and abstract to education@electrochem.org for consideration.