Selvamanickam
Professor Manuel Quevedo-Lopez of University of Texas-Dallas will be giving a seminar titled “Advanced Materials and Devices for Flexible Electronics” at 10 a.m. on June 20 in W122-D3. Please see below for Professor Quevedo-Lopez’s biography as well as the abstract for his seminar.
Advanced Materials and Devices for Flexible Electronics
Prof. Manuel Quevedo-Lopez
Department of Materials Science and Engineering
University of Texas at Dallas
ABSTRACT:
The development of low temperature device technologies that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible, low metal content, sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, neutron/gamma-ray/x-ray detectors, etc. In this talk, our efforts to develop novel CMOS integration schemes, circuits, memory, sensors as well as novel contacts, dielectrics and semiconductors for flexible electronics are presented. In particular, we discuss fundamental materials properties including crystalline structure, interfacial reactions, doping, etc. defining device performance and reliability of organic (PVDF, Pentacene, TIPS-PC, etc.) and inorganic (ZnO, IGZO, CdS, CdTe, etc) materials. Materials characterization methods including RBS, XPS, XRD, etc. are used to analyze materials deposited by pulsed laser deposition, chemical bath deposition and inkjet printing.
With the materials developed here (ZnO, IGZO and II-VI) a novel approach to fabricate Thin Film Transistors (TFTs) with mobilities as high as ~30 cm2/V s, Ion/Ioff of ~109 and VT shift of less than ~0.1 eV is demonstrated. To achieve these TFTs characteristics, a variety of contact materials, gate dielectric, annealing conditions and device structures were studied. The factors affecting VT instability are also presented and correlated to electrode materials, gate dielectric, and post-annealing. In short, TFT instability is correlated to traps and impurities at the dielectric/semiconductor and/or semiconductor film. In addition, integration of these TFTs in CMOS circuits is demonstrated. In particular, a variety of logic gates and FRAM memory cells are demonstrated. Finally, TFTs on flexible and transparent substrates with excellent stability and mobility (~10-18 cm2/V-s) are demonstrated.
Dr. Manuel Quevedo-Lopez is currently an associate Professor in the Department of Materials Science and Engineering at the University of Texas at Dallas. He received his PhD in Materials Science at The University of North Texas (2002). In 2002 he joined Texas Instruments Silicon Technology Development Group as Member of Technical Staff (MTS). While at Texas Instruments he was appointed SEMATECH assignee from 2004-2006. During his industrial experience, He worked extensively in advanced gate stack materials for Si-based technology. In April 2007 He joined the University of Texas as Dallas as Research Professor and in September 2010 he was appointed Associate Professor at the Materials Science and Engineering Department in the Erik Jonsson School of Engineering and Computer Science. Prof. Quevedo has authored or co-authored over 125 publications in peer reviewed journals, 25 peer reviewed conference proceedings, 10 US patents and given more than 45 invited talks. Dr. Quevedo has also has organized several international meetings. He is a member of the Materials Research Society, AVS and IEEE. His interests include materials and devices for flexible electronics, flexible non-volatile memory, large area sensors and novel nanostructured semiconductor, dielectrics and contacts for TFT and Energy applications. He currently manages a group of about 16 graduate students and 3 post-docs.