Speaker: Dr. Robert M. Wallace, Professor and Erik Jonsson Distinguished Chair
Title: High-K Dielectrics: A Perspective on Applications from Silicon To 2D Materials
Affiliation: University of Texas at Dallas
In the 1990’s, research accelerated on addressing the limits of the industry standard gate dielectric: SiO2. With the most aggressive integrated circuit scaling, it became clear that standby power for MOSFETs required the insertion of a gate dielectric material that reduced tunneling leakage while enabling performance expectations. Leveraging prior dielectric research and after exploring several dielectric material candidates, [1,2] Hf-based dielectrics became the dominant choice and were established in commercial Si technology fabrication processes in 2007 after at least a decade of research.  Although perhaps forgotten among today’s 3D FET technologies, the introduction of a new gate dielectric, simultaneously with metal gate materials, was considered quite revolutionary in its day, and this development, in conjunction with other device engineering aspects like strain, enabled the continued march of the industry along Moore’s original predictions. Since that time, the research on incorporating high-k dielectrics has expanded to address alternative channel materials including Ge, III-V, wide band gap semiconductors, and, most recently, perhaps the ultimate limit in channel scaling – atomically thin 2D materials.  This talk, from the author’s perspective, will review some of these developments and provide some context on the resilience of the materials research as well as the challenges and opportunities that lie ahead. 
This work is supported in part by the US/Ireland R&D Partnership (UNITE) under the NSF award ECCS-1407765, and (iv) the Erik Jonsson Distinguished Chair in the Erik Jonson School of Engineering and Computer Science at the University of Texas at Dallas.
 J. Robertson and R.M.Wallace, Materials Science and Engineering R, 88, 1-41 (2015)
 G.D.Wilk, R.M.Wallace, and J.M.Anthony, Journal of Applied Physics 89 5243 (2001)
 M.T. Bohr, R.S. Chau, T. Ghani, K. Mistry, IEEE Spectrum. 44 (29) (2007).
 S.J. McDonnell and R.M.Wallace, Thin Solid Films, 616, 482 (2016).
 R.M.Wallace, ECS Transactions 80(1), 17 (2017)
Robert M. Wallace received his B.S. in Physics and Applied Mathematics in 1982 at the University of Pittsburgh where he also earned his M.S. (1984) and Ph.D. (1988) in Physics, under Prof. W. J. Choyke. From 1988 to 1990, he was a postdoctoral research associate in the Department of Chemistry at the Pittsburgh Surface Science Center under the late Prof. John T. Yates, Jr.
In 1990, he joined Texas Instruments Central Research Laboratories as a Member of Technical Staff (MTS) in the Materials Characterization Branch of the Materials Science Laboratory, and was elected as a Senior MTS in 1996. Dr. Wallace was then appointed in 1997 to manage the Advanced Technology branch in TI’s R&D which focused on advanced device concepts and the associated material integration issues. In 2003, he joined the faculty in the Erik Jonsson School of Engineering and Computer Science at the University of Texas at Dallas (UTD) as a Professor of Electrical Engineering and Physics. He is a founding member of the Materials Science and Engineering program at UTD, served as an interim head for the program. Dr. Wallace also has appointments in the Departments of Electrical Engineering, Mechanical Engineering, and Physics.
Research in the Wallace group focuses on the study of surfaces and interfaces, particularly with applications to electronic materials and the resultant devices fabricated from them. Current interests include materials systems leading to concepts that may enable further scaling of integrated circuit technology and beyond CMOS-based logic. These include the study of the surfaces and interfaces of compound semiconductor systems including arsenides (e.g. InGaAs), nitrides (e.g. GaN), phosphides (e.g. InP), as well as antimondies (e.g. GaSb), and most recently 2D materials such as graphene and transition metal dichalcogenides. He has authored or co-authored over 375 publications in peer reviewed journals and proceedings with over 20000 (29000) citations according to Scopus (Google Scholar).
Dr. Wallace is also an inventor on 45 US and 27 international patents/applications, and a co-inventor of the Hf-based high-k gate dielectric materials now used by the semiconductor industry for advanced high performance logic in microprocessors. He was named Fellow of the AVS in 2007 and an IEEE Fellow in 2009 for his contributions to the field of high-k dielectrics in integrated circuits.