PhD Electrical & Computer Science Northwestern University June 1983
After being recruited to Illinois in 1984 by John Bardeen to work on the 1D charge density wave problem Professor Lyding constructed the first atomic resolution scanning tunneling mi-croscope (STM) in the Midwestern United States and one of the earliest STMs in the US. He followed this by inventing an ultra-stable STM in 1987 that was patented (US Patent 4,841,148) and licensed by the University of Illinois to RHK and McAllister Technical Services. Lyding’s design has been copied worldwide and has also been included in major textbooks on surface science.
In 1994 Professor Lyding developed a novel new STM-based nanofabrication scheme and achieved atomic resolution patterning of silicon surfaces through the selective desorption of hydrogen. This method was immediately recognized and copied worldwide with Lyding giving scores of invited and several plenary talks. His initial paper on the subject [Appl. Phys. Lett. 64, 2010 (1994)] has been cited 487 times. Lyding’s initial work uncovered the fact that there were two distinct physical phenomena associated the hydrogen desorption process. This led to collaboration with Dr. Phaedon Avouris at IBM who modeled these processes. Lyding was recognized with an IBM Partnership Award in 1996 which led to a further study of the desorption process with a cryogenic ultrahigh vacuum (UHV) STM constructed in Lyding’s lab. [Physical Review Letters [80, 1336 (1998), cited 221 times] and the development of feedback controlled lithography for single atom precision hydrogen desorption [Nanotechnology 11, 70 (2000), cited 208 times].
In 1995 Lyding discovered a giant isotope effect when hydrogen was replaced by deuterium on silicon surfaces, in an experiment suggested by Avouris. STM desorption studies showed that deuterium was two orders of magnitude more difficult to desorb than hydrogen. This was published in Chemical Physical Letters [257, 148 (1996)] and Surface Science [363, 368 (1996)] with 157 and 172 citations respectively. In a meeting with Professor Karl Hess, Lyding made the connection between the isotope effect he had observed in the STM experiments and the hydrogen-related hot-carrier degradation in CMOS transistors. Lyding proposed replacing hydrogen with deuterium in CMOS to see if the same isotope effect could reduce the degradation. Lyding and Hess worked with Dr. Isik Kizilyalli of Lucent to treat commercial CMOS chips in deuterium and their initial results showed a dramatic 50x reduction in hot-carrier degradation. Their first paper [Lyding, Hess and Kizilyalli, Appl. Phys. Lett. 68, 2526 (1996)] has been cited 367 times. This result was met with major publicity and was rapidly confirmed by industrial laboratories worldwide. Deuterium has been used in commercial production by several major chip manufacturers, most recently by Samsung, under license from the University of Illinois, for the ARM processors used in iPhone and iPad devices. In 1996 Lyding was called to Washington D.C. by Senator Bill Frist to present the deuterium result to a Senate conference forum on science and technology, exploring the unanticipated technology benefits of supporting fundamental research.
In 2001-2002 Lyding began exploring carbon nanotubes on silicon as a potential hybrid approach to using nanotubes. Unfortunately, at that time there was no technique to integrate carbon nanotubes with clean, air sensitive surfaces. STM studies up until then relied on solution deposition of nanotubes onto inert gold surfaces. To circumvent this problem, Lyding developed a new method that he termed dry contact transfer (DCT) [Appl. Phys. Lett. 83, 5029 (2003), cited 84 times] in which nanotubes could be brought into a UHV environment and then directly stamped onto atomically clean surfaces. Lyding’s group published a number of papers between 2003 and 2007 using DCT to place nanotubes on silicon and III-V compound semiconductor surfaces. In these papers they noted a strong interaction between nanotube and substrate based on the relative alignment of the nanotube axis and substrate atomic row directions. Strong doping effects and nanotube bandgap changes were also observed, underscoring the detailed complexity of potential technological applications of carbon nanotubes.
In 2007 Lyding extended the DCT method to the study of monolayer graphene on silicon and III-V substrates. His first paper on graphene [Nanotechnology 19, 015704 (2008)] was recognized as one of the most accessed papers in Nanotechnology for 2008. Unlike nanotubes, finite sheets of graphene have edges and it was predicted in 1996 that edges with the so called zigzag symmetry would exhibit a metallic edge state that should have a pronounced effect on transport through graphene quantum dots or nanoribbons. However, experiments didn’t see this effect leading to postulation in the literature that nonuniformity and edge disorder were obfuscating the observation of edge effects. Through DCT of graphene on silicon Lyding and graduate student Kyle Ritter demonstrated for the first time the existence of the metallic zigzag edge state. Furthermore, they studied quantum size effects down to 2nm lateral graphene dimensions, an order of magnitude smaller than previous studies. This work was published in Nature Materials [8, 235 (2009), cited 505 times]. Lyding’s most recent work on graphene has demonstrated the admixture of graphene and substrate electron wavefunctions [Nano Lett. 10, 3446 (2010)], silicon-induced metallic states in semiconducting graphene quantum dots [Nano Lett. 11, 2735 (2011)], and that the copper (111) surface is the optimal copper surface for monolayer graphene growth [Nano Lett. 11, 4547 (2011), cited 156 times].
In 2006 Lyding invented a novel process for sharpening conductive probes down to sub-5nm radii. His method, Field-Directed Sputter Sharpening (FDSS), is based on ion sputtering of a biased probe. The probe bias establishes an inhomogeneous electric field at the tip apex that deflects the incoming ions and selectively sharpens the apex, which increases the field strength and enhances the effect. High performance STM and AFM tips with super hard coatings have now been demonstrated and Lyding is now the Chief Technical Officer of Tiptek, LLC, a new start-up company to commercialize this technology. The US Patent Office has issued FDSS patents (8,070,920 and 8,819,861).
For more information
I have developed a new permanent course ECE 481 - Nanotechnology, which I offer every Spring semester. This course is offered with 3 hours credit for advanced undergraduate students and 4 hours of credit for graduate students. I also teach ECE 444 in which students fabricate silicon ICs in a unique laboratory facility.
Carbon nanoelectronics, based on carbon nanotubes and graphene are being actively researched for future semiconducting device applications. To this end it is imperative to understand their interactions with technological substrates at the atomistic level. We have developed ultra-clean nanotube deposition and STM spectroscopic methodologies that achieve this level of understanding. Subtle effects are being seen for the first time and are being modeled with first principles theory and simulations.
Undergraduate Research Opportunities
Our group regularly involves undergraduate researchers in nanotechnology projects aimed at gaining an atomic level understanding of important phenomena that govern the development of nanoelectronic devices. Current projects involve the use of scanning tunneling microscopy (STM) to study carbon nanotubes, graphene and bonded silicon wafers. We are also involved in controlling the growth of carbon nanotubes.
- Carbon Nanotube Purification
- Graphene Growth, Characterization and Device Fabrication
- Ultra-Sharp Probe Fabrication
- Integrating Graphene with Silicon and III-V Semiconductors
- Chirally Pure Nanotube Growth
- Dry Contact Transfer (DCT) Patterning on Nanostructures on Surfaces
- Carbon Nanotube Purification
- Oxide Silicon Interface Mapping
- Cross-Sectional STM of Semiconductor Heterostructures
- Atomically Precise Dopant Mapping
- Deuterium Processing and Hot Electron Degradation in Semiconductor Devices
- Growth of 3D silicon nanostructures
- Carbon Nanotubes and Carbon Based Nanotechnology merged with Silicon and III-V Semiconductors
- Silicon Based Molecular Electronics
- STM-Based Nanolithography and Nanofabrication
- Scanning Tunneling Microscopy and Spectroscopy
- Advanced carbon-based materials and nanoscale devices
- Nano-electronics and single electronics
- Quantum nanostructures for electronics and photonics
- Semiconductor electronic devices
- Semiconductor materials
- Poster Award - MRS Meeting (2006)
- Best Paper Award - IEEE WMED Workshop (2005)
- Best Paper Award - IEEE Workshop on Microelectronics & Electron Devices (2005)
- Advisors List for advising excellence, College of Engineering (2001)
- Finalist, Discover Magazine Technical Innovation Award (2001)
- Eta Kappa Nu - Alpha Chapter (2000)
- Finalist, Feynman Prize in Nanotechnology (2000)
- Fellow, American Vacuum Society (2000)
- Finalist, Feynman Prize in Nanotechnology (1999)
- DARPA Sustained Excellence Award (1998)
- Philips Visiting Scholar, Haverford College (1998)
- Fellow, American Physical Society (1997)
- UIUC University Scholar (1997)
- Associate, Center for Advanced Study (1996-1997)
- IBM Partnership Award (1996)
- Beckman Fellow, Center for Advanced Study (1987-1988)
- IBM Postdoctoral Fellowship (1984)
- Incomplete List of Excellent Teachers (Spring 2007)
- Incomplete List of Excellent Teachers (Spring 2005)
- Advisors List for Advising Excellence (2001)
- Incomplete List of Excellent Teachers (1987)
- Tau Beta Pi Outstanding Teaching Award (1984)
- Poster Award - MRS Meeting, 2006
- Best Paper Award - IEEE WMED Workshop, 2005
- Best Paper Award - IEEE Workshop on Microelectronics & Electron Devices, 2005
- Finalist, Discover Magazine Technical Innovation Award, 2001
- Finalist, Feynman Prize in Nanotechnology, 2000
- Finalist, Feynman Prize in Nanotechnology, 1999
- Fellow, American Vacuum Society, 2000
- DARPA Sustained Excellence Award, 1998
- Philips Visiting Scholar, Haverford College, 1998
- Fellow of APS, 1997
- UIUC University Scholar, 1997
- Senior Member of IEEE, 1997
- IBM Partnership Award, 1996
- Asssociate, Center for Advanced Study, 1996-97
- Who's Who in Science and Engineering
- Who's Who
- Arnold O. Beckman Research Award, U Of I, 1989
- Beckman Fellow, Center for Advanced Study 1987-88
- Arnold O. Beckman Research Award, Univeristy of Illonois, 1985
- Arnold O. Beckman Research Award, University of Illinois, 1984
- Arthur K. Doolittle Award, American Chemical Society, 1983
- IBM Postdoctoral Fellow 1983
Public Service Honors
- Presented the deuterium processing discovery on behalf of the Science Coalition Senate Republican Conference Issue Forum on Science and Technology, Washington, DC, 25 March 1996.
- Presented keynote address at the American Chemical Society High School Teacher's Night Awards Banquet, Sangamon State University, May 6, 1994, Springfield, IL.