Dr. Jean-François Veyan - Lab Manager
After my Ph.D., obtained at the Universidad Tecnica Federico Santa Maria, Valparaiso, Chile, I joined Prof. Y. J. Chabal’s group in 2005, on a post-doctoral position, at Rutgers University, New Jersey. I was in charge of the Hydrogen Storage in Metal Complex Hydrides project, which is now the responsibility of Irinder S. Chopra (Ph. D. Student). I upgraded an Ultra High Vacuum (UHV) system and obtained the critical data for our study on Alane formation on the Al(111) surface. I also developed an experimental setup for the study of Xenon Difluoride interaction with pure compounds and their oxides, for applications in Micro (and Nano) Electro-Mechanicals Systems (MEMS, NEMS). That project has been partially transferred to my colleague Dr. Katy Roodenko. In parallel, I initiated the research on Hydrogen Storage in Metal Organic Frameworks, project transferred to Nour Nijem (Ph. D. Student). I am currently involved in the Atomically Precise Manufacturing Consortium project, studying the Atomic Layer Epitaxy growth of silicon and germanium on Si(100)-(2x1) surface using Disilane and Digermane as precursor gas. On this project, I am supervising Don Dick (PhD student), Gaurav Rao and Perrine Mathieu (undergraduate students).
My challenge, in Prof. Chabal’s group at UT Dallas, is the design and construction of a complex UHV Surface Science facility, to study surface and nanostructure modifications on metals and semiconductors (III-V). This facility combines techniques like Fourier Transform Infra-red Spectroscopy (FT-IR, performed in reflection, internal multiple reflection and transmission geometries), X-ray Photoelectron Spectroscopy (XPS), and Low Energy Ion Scattering (LEIS), connected to a UHV surface science preparation chambers equipped with e-beam evaporators and CVD/ALD capability, in the LN2 to high (1400 K) temperature range. This facility will be interfaced to three Atomic Layer Deposition reactors (ALD), specially designed for in-situ FT-IR, Elipsometry and Residual Gas Analysis (RGA), two UHV chamber for Plasma induced surface modification (one for remote plasma and one for direct plasma), and other UHV systems equipped with Temperature Programmed Desorption (TPD), Auger Electron Spectroscopy (AES), Low Energy Electron Diffraction (LEED), Raman Spectroscopy. Furthermore, I am in charge of the laboratory organization, safety and management. I am involved in most research projects of the group helping my colleagues in building, designing and machining specific parts their experimental setup require.
Dr. Jinhee Kwon
My research focuses on characterization of thin film growth by atomic layer deposition (ALD). Knowledge of surface reactions and initial film growth mechanisms is crucial in controlling and optimizing film properties, and investigation in-situ during ALD processes is almost the only way to access those knowledge. We incorporated in-situ Fourier transform infrared (FTIR) spectroscopy, spectroscopic ellipsometry (SE) and mass spectrometry to ALD reactors which can be ultimately connected to X-ray photoemission spectroscopy (XPS) and low-energy ion scattering (LEIS) chambers through load-lock systems. The films that I am studying include key materials for future microelectronics such as high-κ dielectrics (Al2O3, HfO2, La2O3, and LaxAlyO3), metals (Cu, TaN and Co) and silicon nitrides. In-situ studies of TANOS (TaN/Al2O3/Si3N4/SiO2/Si) gate stacks are also one of my research interests; i.e., effects of thermal stress on interfaces, growth mechanisms of TaN ALD on high-κ dielectric, and annealing effects on metals etc. Information derived from the results of in-situ studies is complemented by ex-situ atomic force microscopy (AFM), X-ray photoemission spectroscopy (XPS), and Rutherford backscattering spectroscopy (RBS).
Dr. Weina Peng
At this moment I am working on two main projects: One is the photocurrent transient in hybrid quantum dots/SAM/Si device, which has a potential application for solar cells. The other project is electrical characterization of SAM/semiconductor interface.
Dr. Katy Roodenko
My MSc degree I obtained at Tel-Aviv university at the group of Applied Physics (http://www.tau.ac.il/~applphys/), headed by prof. Abraham Katzir. The subject of my thesis was construction of near-field scanning optical microscope (NSOM) for application in infrared spectral range. After finishing my MSc studies, I pursued my PhD degree at ISAS (http://www.isas.de/index.php?id=73) and TU-Berlin in Germany, working under the supervision of Prof. Dr. Norbert Esser and Dr. Karsten Hinrichs. My PhD dissertation dealt with optical characterization of ultra-thin organic films electrochemically grafted on metallic and semiconducting surfaces.
In 2009 I joined the group of Prof. Yves Chabal at UT Dallas, where my research is focused on non-destructive spectroscopic characterization of thin-films and nanostructured materials. I use multiple surface-sensitive techniques, such as Raman, FT-IR, XPS and ellipsometry to address surface engineering at nanometer-scale. For example, in collaboration with Qualcomm we studied organic modification of highly hydrophilic aluminum oxy(fluoride) surfaces with Octadecyltrichlorosilane (OTS) and found out this type of surface functionalization leads to hydrophobic, well-protected surface, which is more suitable in MEMS technology than the uncoated surfaces [1]. Our studies relied on FT-IR and XPS data for characterization of molecular coverage and orientation as well as for stability tests of these layers to storage in air.
Another example of advanced surface characterization is application of Raman spectroscopy for optical analysis of Ge nanowires. In these studies, we used a so-called “phonon confinement model”, which we expanded to address the crystallographic orientation of nanostructures as well as the interplay between the temperature of the nanowires and their size [2]. In every project I aim at quantitative analysis of my data, and I employ multiple modeling methods to interpret optical signals collected from thin films and nanostructured materials. This way, we have a unique opportunity to obtain an insight into macroscopic properties of surfaces and interfaces at a nanoscale. In my research I always enjoy working with other students and post-docs. I frequently instruct undergraduate students who come to our lab to gain knowledge on advanced surface engineering and surface characterization tools.
References:
[1] K. Roodenko et al., J. Phys. Chem. C, 114, 22566 (2010)
[2] K. Roodenko et al., Phys. Rev. B 82, 115210 (2010).
Dr. Oliver Seitz
I am responsible for Professor Chabal's program on wet chemical functionalization of semiconductor surfaces. This research represents a platform for the development of future microelectronic devices, sensors, and energy materials. I am using synthesis methods that I, to an extent, developed in applications involving novel molecules, and a number of characterization methods to study the result of these syntheses, such as infrared absorption spectroscopy, ellipsometry, scanning electron microscopy, atomic force microscopy, x-ray photoelectron spectroscopy, and electrical transport measurements.
I set up the chemistry lab for Professor Chabal's research group at the time of his arrival to the University of Texas at Dallas. In my time at the lab, I've had to manage and supervise all levels of members in the group, from undergraduates to newly assigned postdocs. At the lab, I have worked on projects including:
- Development of platforms for controlled deposition/attachment/dispersion of densely packed quantum dots monolayer, and investigation of energy transfer for future photovoltaic applications
- Controlled deposition of metallic contacts on organic monolayers using atomic layer deposition (ALD) for molecular electronic applications
- Investigation of etching and reactivity of SiC-SiO2 and SiC-N-SiO2
- Development of robust and high quality organic monolayer, containing different reactive head groups, directly attached to silicon surfaces for sensor application or nanoparticle attachment
- Development of biosensor platform: investigation of the stability and the reliability of the sensor, comparison of detection limits between nanowires and nanoribbons, sensors, adaptation of the biosensing chemistry for compatibility with device fabrication (Project funded by Texas Instruments)
Academic background
Oliver Seitz received his Master degree in Chemical-Physics from the University Paris 7, Denis Diderot (Paris, France) in 2000, with a specialization in surfaces, interfaces, and evolving materials. In 2004, he received his Ph.D. in Chemistry and Material Science from the University of Versailles (France) where he investigated the surface modification of III-V semiconductor electrodes by anodic treatment in liquid ammonia, including determining the mechanism of reactions. Later on, he joined for 3 years, Prof. David Cahen’s group at the Weizmann Institute of Science (Israel), where he investigated the preparation and characterization of high quality organic monolayers directly bonded on silicon surfaces, with a focus on their electrical properties and current transport mechanisms. Finally, he joined Prof. Yves Chabal in 2008, at the University of Texas at Dallas, where he is currently working.
Dr. Peter Thissen
My research deals with experimental and theoretical studies in the chemistry of surfaces and interfaces. Understanding the chemistry of surfaces and interfaces is essential for many phenomena in geology, atmospheric chemistry, environmental protection, corrosion, sensors, heterogeneous catalysis and electronics. On the one hand, I try to address the point of interest in different surface sensitive experiments, including Fourier transform infrared spectroscopy (FTIR), X-ray spectroscopy (XPS), contact angle, atomic force microscopy (AFM), and others [1]. On the other hand, I use first principles calculations to understand the fundamental backgrounds on an atomic level [2]. Thus my research bridges the gap between experimental and theoretical studies.
List of chosen Publications:
[1] Thissen et al., Stability of Phosphonic Acid Self-Assembled Monolayers on Amorphous and
Single-Crystalline Aluminum Oxide Surfaces in Aqueous Solution, Langmuir, 2010, 26 (1),
pp 156–164.
[2] Thissen et al., Water adsorption on the alpha-Al(2)O(3)(0001) surface,
PHYSICAL REVIEW B 80, 245403 (2009).
