Ekerdt, John G. Ph.D.

Ekerdt, John G. Ph.D.

Dick Rothwell Endowed Chair in Chemical Engineering
Associate Dean for Research in Engineering

Photo of John G. Ekerdt

Office: CPE 4.468 Mailing Address:
Phone: (512) 471-4689 The University of Texas at Austin
Fax: (512) 471-7060 Department of Chemical Engineering
Email: ekerdt@che.utexas.edu 200 E Dean Keeton St. Stop C0400
UT Mail: C0400 Austin, TX 78712-1589

Research Areas: Advanced Materials, Polymers & Nanotechnology and Energy

Research Group Website 

Research Presentation for Prospective Graduate Students 

Educational Qualifications

Ph.D., Chemical Engineering, University of California Berkeley (1979)
B.S., Chemical Engineering, University of Wisconsin (1974)

Focus

Surface, growth and materials chemistry of ultrathin metal, dielectric, ferroelectric, and polymer films and silicon nanostructures. Nucleation and growth kinetics of films and nanostructures, structure-property relationships, and site-specific reactions.

Graphic showing crystalline STO grown at 250 C, directly on a template layer.

  Illustration how one perylene-based molecule was used to titrate strained siloxane groups on silicon dioxide.
Figure 1: We are exploring the growth of crystalline perovskite films on Si(001).  The ABO3 perovskites, such as SrTiO3 (STO), LaAlO3, BaTiO3, are grown by atomic layer deposition (ALD) on a 1.6 nm thick STO template layer that is grown using molecular beam epitaxy.  The growth chambers are connected to an analysis chamber allowing in situ transfer and characterization.  The transmission electron microscopy image above shows crystalline STO grown at 250 C, directly on a template layer. Figure 2: We are studying the chemical nature of the sites where semiconductor and metal particles and films nucleate on oxide surfaces.  We employ fluorescent probes that are designed to react with and bind to different possible sites.  The high sensitivity of this technique allows us to detect defects at concentrations as low as 0.0001 sites nm-2.  The image above illustrates how one perylene-based molecule was used to titrate strained siloxane groups on silicon dioxide.

Research

The focus of my research is on the surface, growth and materials chemistry of metal, dielectric, ferroelectric, and polymer thin films, and of silicon nanostructures.  We seek to understand and describe nucleation and growth of films and nanostructures, their structure-property relationships, and site-specific reactions that lead to their formation.  The programs are motivated by applications in electronic materials and sensors.  The research programs are highly interdisciplinary and involve collaborations with faculty in chemical engineering, physics and electrical engineering, and researchers in industry.

Metal films find applications in sensors, optics and microelectronics, and as the critical dimensions or size of the applications and systems decrease, the metal film’s thickness will decrease to tens of atomic diameters at most and must have a specific microstructure.  Our program seeks to describe how films form, with an emphasis on nucleation and island coalescence, the evolution of interfacial layers that bind the film to the substrate, how properties of bulk materials scale with thickness, and precisely how short range order is preserved as the film thickness approaches thicknesses that are ten atomic diameters.

The research on silicon alloy nanoparticle growth chemistry on dielectric surfaces seeks to understand how to grow nanoparticles of a particular diameter and density, and how to precisely position these nanoparticles on the surface.  We have explored the chemistry and kinetics of nanoparticle growth in detail on silicon dioxide and find the nucleation is controlled by defects in the oxide surface; our current focus is to determine the chemical nature of defects on silicon dioxide and more generally on additional, technically relevant dielectric surfaces.

The research on dielectric and ferroelectric films seeks to understand the chemical reactions responsible for atomic layer deposition growth and the interfacial reactions responsible for forcing the films to remain amorphous or to grow in a crystalline form.  Studies with hafnia explored atomic layer deposition growth of periodic structures in which ions, such at La, Al and Ta, are incorporated to delay the onset of crystallization temperature and stabilizing the amorphous phase.  Studies with ferroelectrics explore homoepitaxy and heteroepitaxy of perovskite films using molecular beam epitaxy and atomic layer deposition and the role of the growth surface termination and methods to enhance wetting/spreading to realize two dimensional epitaxial growth and control the properties in the ferroelectric layer.  These studies explore the monolithic integration of functional oxides with silicon to allow for integrated heterostructures on the same silicon platform as the integrated silicon circuits.

Awards & Honors

Fellow of the American Association for the Advancement of Science (2012)
American Society for Engineering Education Chemical Engineering Division Chemstations Award (2012)
Fellow of the American Institute of Chemical Engineers (2006)
Joe J. King Professional Engineering Achievement Award, College of Engineering, University of Texas (2005)
Hamilton Book Awards, Runner-up for Chemical Reactor Analysis and Design Fundamentals, University Co-op Society (2003)
Charles M. A. Stine Award in Materials Science and Engineering, American Institute of Chemical Engineers (2001)
Phi Kappa Phi Award for Dedicated Service in the Promotion of Excellence in Higher Education (1997)
Dick Rothwell Endowed Chair in Chemical Engineering (2001)
Chemical Engineering Department Teaching Award (1994)
Z. D. Bonner Professorship in Chemical Engineering (1991-2001)
Quantum Chemical Corporation Endowed Fellow in Engineering (1990-91)
Laurence E. McMakin Centennial Fellow in Chemical Engineering (1983-90)
Best Fundamental Paper, South Texas Section of AIChE (1980)
The University of Texas at Austin Engineering Foundation Faculty Excellence Award (1980, 1983, 1987, 1993)
Outstanding Young Member Award, 1984, South Texas Section of AIChE
Outstanding Engineering Teaching by an Assistant Professor, University of Texas (1985)

Selected Publications

  • Epitaxial strontium titanate films grown by atomic layer deposition on SrTiO3-buffered Si(001) substrates (Martin D. McDaniel, Agham Posadas, Thong Q. Ngo, Ajit Dhamdhere, David J. Smith, Alexander A. Demkov, and John G. Ekerdt) Journal of Vacuum Science and Technology A 31, 01A136- (1-9) (2013).
  • Epitaxial growth of LaAlO3 on SrTiO3-buffered Si(001) substrates by atomic layer deposition (Thong Q. Ngo , Agham Posadas, Martin D. McDaniel, Domingo A. Ferrer, John Bruley, Chris Breslin, Alexander A. Demkov, and John G. Ekerdt) Journal of Crystal Growth 363, 150-157 (2013).
  • Growth of epitaxial oxides on silicon using atomic layer deposition: Crystallization and Annealing of TiO2 on SrTiO3-buffered Si(001) (M.D. McDaniel, A. Posadas, T. Q. Ngo, A. Dhamdhere, D. J. Smith, A. A. Demkov, J. G. Ekerdt) Journal of Vacuum Science and Technology B 30, 04E111-(1-6) (2012).
  • Depolymerization of oak wood lignin under mild conditions using the acidic ionic liquid 1-H-3-methylimidazolium chloride as both solvent and catalyst (Blair J. Cox, John G. Ekerdt) Bioresource Technology 118, 584-588 (2012).
  • Optical properties of La-incorporated HfO2 upon crystallization (Tuo Wang, Junwei Wei, Michael C. Downer, John G. Ekerdt) Applied Physics Letters 98, 122904 (2011).
  • Hot-wire CVD of Ge nanoparticles on silicon-etched silicon dioxide (Joseph M. McCrate, Navnethakrishan Salivati, John G. Ekerdt) Journal of Crystal Growth 321 131-135 (2011).