Robert M. Wallace
Professor - Physics (affiliated courtesy)
Professor - EE (affiliated courtesy)
Professor - ME (affiliated courtesy)
Louis A. Beecherl, Jr. Distinguished Professor
1988 PhD Physics, University of Pittsburgh
1984 MS Physics, University of Pittsburgh
1982 BS Physics and Applied Mathematics, University of Pittsburgh
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. Driven by integrated circuit scaling and industrial experience, our work has led to participation on several nationally renowned academic centers sponsored by the Semiconductor Research Corporation with tasks focusing on the interfacial physics and chemistry of metals and dielectrics in contact with semiconductor and semimetal surfaces, and the resultant device behavior correlations.. This work has also recently enabled a new NSF-sponsored program with colleagues in Ireland and Northern Ireland. As such, the majority of our work is interdisciplinary, with attention to the fundamental science as well as potential applications and any associated constraints.
Our current interests include materials systems which (1) extend complementary metal-oxide-semiconductor devices as well as (2) materials systems leading to concepts beyond CMOS-based logic. In the former category, we have current research programs engaged in the study of high dielectric constant (“high-k”) insulating films on compound semiconductor systems including arsenides (e.g. InGaAs), nitrides (e.g. GaN), phosphides (e.f. InP), as well as antimondies (e.g. GaSb). This research thrust extends our previous work on high-k dielectrics on more conventional Si-based materials, where an emphasis is made on the correlation of physicochemical properties and electronic performance. In addition to laboratory studies of these compound semiconductor interfaces and surfaces, device fabrication is conducted in our cleanroom facilities for this work. In the latter category, we have active programs in the study of graphene surfaces as well as atomic-scale lithography to fabricate well-defined quantum-dot and qubit structures. This work is funded through a combination of SRC funding (graphene) as well as DARPA funding. Ourwork on Graphene includes studies of dielectric integration and device fabrication that enables the investigation of device physics beyond conventional charge transport including room temperature condensates (“pseudospin”).
- R.M.Wallace and G. Wilk, "High-k Dielectric Materials for Microelectronics," Critical Reviews in Solid State and Materials Sciences 28, 231 (2003) (Invited Review Article).
- G.D.Wilk, R.M.Wallace and J.M.Anthony, "High-k Gate Dielectrics: Current Status and Materials Properties Considerations", Journal of Applied Physics 89, 5243(2001). (Invited Review Article, >3100 citations)
- C. L. Hinkle, M. Milojevic, B. Brennan, A. M. Sonnet, F. S. Aguirre-Tostado, G. J. Hughes, E. M. Vogel, and R. M. Wallace, "Detection of Ga suboxides and their impact on III-V passivation and Fermi-level pinning," Applied Physics Letters 94 162101(2009).
- C. L. Hinkle, A. M. Sonnet, E. M. Vogel, S. McDonnell, G. J. Hughes, M. Milojevic, B. Lee, F. S. Aguirre-Tostado, K. J. Choi, H. C. Kim, J. Kim, and R. M. Wallace, "GaAs interfacial self-cleaning by atomic layer deposition," Applied Physics Letters 92, 071901 (2008).
- M. Milojevic , C.L.Hinkle, F. Aguirre-Tostado , H.C. Kim , E,M,Vogel, J. Kim, and R.M.Wallace, "Half-cycle atomic layer deposition reaction studies of Al2O3 on (NH4)2S passivated GaAs(100) surfaces," Applied Physics Letters 93 252905 (2008).
- Fellow IEEE
- Fellow AVS