◥ Speaker: Dr. Do Han Kim (MIT)
◥ Date: 7 Sep, 2017 (Thu) 14:30
◥ Place: Seminar room 1 (#1101) @ W1-3 Bldg.
◥ Title: Making Tinier Patterns
The semiconductor industry has made a great effort to produce sub-10 nm patterns in a cost-effective way as the feature size is getting closer to the limit of the wavelength of UV light source in conventional photolithography. As an enabling technology, block copolymers (BCP) can be self-assembled to nanoscale structures by thermal anneal with no UV light. This seminar presents a new technology employing directed self-assembly (DSA) of highly segregating BCP and a topcoat deposited by initiated chemical vapor deposition (iCVD). iCVD, enabled the deposition of crosslinked polymeric topcoat on the BCP films without any damage to the BCP films. We discovered that the iCVD made the unique interface between the BCP films and topcoat through grafting intrinsically. The interface achieved the non-preferential surface for domains of the multiple BCPs, thereby resulting in the desirable perpendicular orientation of the BCP domains. Besides, we fabricated additional topcoat patterns on the BCP films by e-beam lithography because the crosslinked topcoat is chemically durable against solvents of e-beam resist. The post-patterning enabled by iCVD permits configuring sub-10 nm patterning area on a Si wafer, which is more beneficial to the interconnect devices in the semiconductor industry. The talk also introduces that iCVD films can be used as an interfacial wetting layer between Si wafer and BCP to control the self-assembly orientation of BCP with hot-filament temperature during the deposition.
The speaker is now a postdoctoral associate of Chemical Engineering at Massachusetts Institute of Technology working with Prof. Karen Gleason. He is developing a sub-10 nm patterning technology using polymer CVD (iCVD) and directed self-assembly processes based on understanding fundamental polymer physics and gas-kinetics observed in two processes. He received Ph.D. of Chemical Engineering from North Carolina State University (NCSU) under supervision of Prof. Gregory Parsons in 2013. During his Ph.D. study, he published a series of papers on atomic layer deposition to deposit ultra-thin films, especially of metal oxides, for engineering surfaces and interfaces of dye-sensitized solar cells. His research interests are on vacuum processing with polymeric and inorganic materials to deposit ultra-thin films over complex structures in nanofabrication and energy applications. Prior to joining NCSU, He worked as an engineer at LCD division of Samsung Electronics. He will join ASM America, Inc. (Phoenix, AZ, USA) as a senior process engineer this fall.