New Precursors and Atomic Layer Deposition Processes
Florian Preischel, Ruhr University Bochum, Bochum, GermanyMartin Wilken, Ruhr University Bochum, Bochum, Niklas Huster, Ruhr University Bochum, Bochum, Marcel Schmickler, Ruhr University Bochum, Bochum, Jan-Lucas Wree, Ruhr University Bochum, Bochum, David Zanders, Ruhr University Bochum, Bochum,
With the wide-spread application of thin films in many modern devices, atomic layer deposition (ALD) has emerged as a suitable method for the deposition of high-quality thin films. Owing to its self-limiting nature, this method offers unmatched conformality and thickness control, even on complex patterned 3D structures. Since ALD is a chemical method that relies on the evaporation of a precursor and its reaction with a substrate’s surface as well as a co-reactant to form the desired material, it is highly dependent on the availability of suitable precursor molecules. This has been the motivation for our group to design and synthesize new metalorganic compounds and demonstrate their usage as precursors for ALD. We present a series of papers featuring a new class of Al, Zn and Sn precursors for the deposition of their respective oxides, based on the 3-(dimethylamino)propyl (DMP) ligand. Furthermore, we give an overview of the development of Cu, Ag and Co precursors for ALD of metal films. Our research covers a range of different ALD methods ranging from thermal ALD to plasma-enhanced ALD (PEALD), spatial ALD and hybrid atomic/molecular layer deposition (ALD/MLD). The synthesized precursors were successfully employed for the deposition of Al2O3 as a gas-barrier layer, for SnO2 based thin film transistor (TFT) devices and ZnO as a gas sensing material. Furthermore, we demonstrated the growth of pure and highly conducting Cu and Ag metal films as well as the deposition of Co metal using new metal alkyl reducing agents. This confirms the potential of our newly developed precursors and processes to be used for a wide range of modern applications.