Steven M. George

About

Steven M. George is a Professor of Chemistry at the University of Colorado Boulder with a Ph.D. from the University of California, Berkeley, and a B.S. from Yale University. His research focuses on surface chemistry, nanotechnology/materials, physical chemistry, and renewable energy. He specializes in the fabrication, design, and properties of ultrathin films and nanostructures, developing new surface chemistries for thin film growth, measuring thin film growth using in situ techniques, and characterizing thin film properties. His work is relevant to technological areas such as semiconductor processing, flexible displays, MEMS/NEMS, Li-ion batteries, and fuel cells. Professor George's research bridges multiple disciplines and involves collaborations across various departments and institutions, including industry and national laboratories. He extensively utilizes atomic layer deposition (ALD) techniques for thin film growth, which are based on sequential, self-limiting surface reactions, allowing atomic layer control and conformal coatings on high aspect ratio structures. His contributions include advancing ALD methods for binary materials like Al2O3, MgO, and TaN, as well as for single-element metal films such as tungsten, and organic polymer films through molecular layer deposition (MLD). His research also explores hybrid organic-inorganic polymers, with applications in gas diffusion barriers, battery electrode stabilization, catalysis, and nano-photovoltaic devices.…

Research topics

• Materials science
• Nanotechnology
• Chemistry
• Metallurgy
• Thermodynamics
• Polymer chemistry
• Optoelectronics
• Physics
• Engineering physics
• Chemical engineering

Selected publications

• Mechanisms of Thermal Atomic Layer Etching

  Accounts of Chemical Research · 2020 · 151 citations

  1st authorCorresponding

  ConspectusAtomic layer control of semiconductor processing is needed as critical dimensions are progressively reduced below the 10 nm scale. Atomic layer deposition (ALD) methods are meeting this challenge and produce conformal thin film growth on high aspect ratio features. Atomic layer etching (ALE) techniques are also required that can remove material with atomic layer precision. ALE processes are defined using sequential, self-limiting reactions based on surface modification and volatile rel…

  DOI

• Thermal atomic layer etching: A review

  Journal of Vacuum Science & Technology A Vacuum Surfaces and Films · 2021 · 122 citations

  This article reviews the state-of-the art status of thermal atomic layer etching of various materials such as metals, metal oxides, metal nitrides, semiconductors, and their oxides. We outline basic thermodynamic principles and reaction kinetics as they apply to these reactions and draw parallels to thermal etching. Furthermore, a list of all known publications is given organized by the material etched and correlated with the required reactant for each etch process. A model is introduced that de…

  DOI

• Low-temperature etching of silicon oxide and silicon nitride with hydrogen fluoride

  Journal of Vacuum Science & Technology A Vacuum Surfaces and Films · 2024-11-18 · 32 citations

  articleOpen access

  Etching of high aspect ratio features into alternating SiO2 and SiN layers is an enabling technology for the manufacturing of 3D NAND flash memories. In this paper, we study a low-temperature or cryo plasma etch process, which utilizes HF gas together with other gas additives. Compared with a low-temperature process that uses separate fluorine and hydrogen gases, the etching rate of the SiO2/SiN stack doubles. Both materials etch faster with this so-called second generation cryo etch process. Pu…

  PublisherDOI

• Molecular layer deposition for the fabrication of desalination membranes with tunable metrics

  Desalination · 2021 · 32 citations

  Senior authorCorresponding
  DOI

• Thermal Atomic Layer Etching of CoO, ZnO, Fe₂O₃, and NiO by Chlorination and Ligand Addition Using SO₂Cl₂ and Tetramethylethylenediamine

  Chemistry of Materials · 2023-02-20 · 20 citations

  articleSenior authorCorresponding

  Thermal atomic layer etching (ALE) of CoO, ZnO, Fe2O3, and NiO was achieved using chlorination and ligand-addition reactions at 250 °C. This two-step process was accomplished by first chlorinating the metal oxide with SO2Cl2. Subsequently, ligand addition to the metal chloride was performed using tetramethylethylenediamine (TMEDA). In situ quadrupole mass spectrometry (QMS) studies on metal oxide powders revealed that CoO, ZnO, Fe2O3, and NiO all formed stable and volatile MCl2(TMEDA) compounds…

  PublisherDOI

Recent grants

• Fundamental Issues for Thermal Atomic Layer Etching

  NSF · $475k · 2016–2019

• In Situ Probing of Atomic Layer Deposition: Surface Chemistry, Film Growth and Electrical Properties

  NSF · $471k · 2004–2007

• Molecular Layer Deposition of Polymers: Nucleation, Surface Chemistry and Nanocomposite Films

  NSF · $480k · 2007–2010

Frequent coauthors

• Andrew S. Cavanagh

  University of Colorado Boulder

  91 shared

• Anne C. Dillon

  Queen's University Belfast

  58 shared

• Victor M. Bright

  University of Colorado Boulder

  46 shared

• Ronggui Yang

  Peking University

  45 shared

• А. И. Абдулагатов

  Dagestan State University

  44 shared

• Alan W. Weimer

  University of Colorado Boulder

  43 shared

• Young‐Hee Lee

  37 shared

• Markus D. Groner

  Forge Nano (United States)

  37 shared

Education

• Ph.D., Chemistry

  University of California, Berkeley

  1983

• B.S., Chemistry

  Yale University

  1977

Awards & honors

• DPS Nishizawa Award from the International Symposium on Dry…
• Faculty Research Award from College of Engineering and Appli…
• University of Colorado at Boulder Faculty Assembly Excellenc…
• American Chemical Society Colorado Section Award, 2004
• R&D 100 Award for Particle-ALD, 2004

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