Spatial Atomic and Molecular Layer Deposition for Flexible Barrier Applications

Daniel James Higgs, University of Colorado at Boulder


This thesis describes equipment and methods for producing and testing thin films deposited by atomic layer deposition and molecular layer deposition. Atomic layer deposition (ALD) is a thin film deposition technique based on the repeated sequential dosing of gaseous reactant (precursor) molecules. ALD films can be deposited with extreme uniformity, Ångström-level thickness control and they can be pin-hole free. The use of ALD and MLD films is desired by many industries including the nanomanufacturing of electronics and improvement of reverse osmosis desalination membranes. There are three main sections to this work.

The first main section describes critical tensile strains of 5 nm – 132 nm ALD ZnO films. Films were measured with 4-point probe and confocal laser scanning microcopy. The second main section describes a new Ca test that was developed based on quartz crystal microbalance (QCM) measurements to measure the oxidation of calcium films by water vapor. The last main section describes a new rotating drum reactor capable of spatial molecular layer deposition (S-MLD). Polyamide films were deposited using trimesoyl chloride (TMC) and m-phenylene diamine (mPD). These polyamides have applications as both gas and desalination membranes. The new spatial MLD tool enables unprecedented nanoengineering of polymer films on a molecular scale.