Funded by National Science Foundation Research Project Improving Sustainability of Atomic Layer Deposition: a Hierarchical Systems Approach Funded by National Science Foundation Funding: $457,902 Funding period: 08/1/2012-07/31/2015

Introduction Atomic Layer Deposition (ALD): the most accurate nano-scale manufacturing technology for fabricating atomic-scale thin films. Wide Applications: Microelectronics Solar Cells Fuel Cells Lithium ion batteries MEMS OLED Photonics Catalysts Biomedical devices and many other applications (Courtesy: Cambridge Nanotech Inc.)

ALD of Al2O3 Nano-Scale Thin Films 2Al(CH3)3 +3 H2O  Al2O3 + 6CH4 Result 0.1+0.01 nm Atomic Layer Deposition of Al2O3: 2Al(CH3)3 + 3H2O  Al2O3 + 6CH4 Silicon Wafer Pulsing H2O to hydroxylate Si Wafer Step 1 Step 3 Pulsing Emission Surface Roughness < 0.3 nm Pulsing H2O to react with Al(CH3)3 Pulsing Al(CH3)3 on hydroxylated Si Wafer Step 2 H2O Al(CH3)3

Research on Improving Sustainability of ALD Three research objectives: Objective 1: Mathematical modeling and experimental investigations of ALD process emissions 1.1. Modeling and validating the ALD precursor use and emission generations 1.2. Experimental investigations of ALD nano-particle emissions Objective 2: Thermodynamic flows and energy modeling of ALD nano-manufacturing system 2.1 Modeling thermodynamic energy flows in ALD system 2.2. Development of a mathematical energy model for ALD system Objective 3: Sustainable scale-up of ALD nanotechnology for industrial productions 3.1. Sustainability of batch-size ALD production system 3.2. Sustainable development of roll-to-roll fast ALD nano-manufacturing technology

Objective 1: Modeling and Test ALD Emissions 1.1. Modeling and validating the ALD precursor use and emission generations Boltzmann equation: 1.2. Experimental investigations of ALD nano-particle emissions

Objective 2: Thermodynamic Analysis of ALD 2.1 Modeling thermodynamic energy flows in ALD system Navier-Stokes equations: 2.2. Development of a mathematical energy model for ALD system Energy consumption of ALD Al2O3

Objective 3: Sustainable Scale-up of ALD 3.1 Sustainability of batch-size ALD production system 3.2. Sustainable development of roll-to-roll fast ALD nano-manufacturing technology Precursors Electricity Substrates Products By-products Emissions/Wastes