DFG SPP 1119 - Inorganic materials by gas phase synthesis: Interdisciplinary approaches to the development, understanding and control of CVD processes

The aim of the project is the complete elucidation of the decay and deposition mechanisms of a single-component precursor by purely theoretical means. The evaluation of new precursor systems is currently mostly based on empirical observations, while "ab initio" methods to elucidate the relevant phenomena are not well developed. The recently developed GaN precursor BAZIGA is interesting because it forms both thin films and nanostructures depending on the deposition conditions. Due to its essentially unimolecular decay pathways, it is ideally suited to demonstrate the feasibility, accuracy and informative value of a combined use of quantum mechanical and continuum mechanical prediction models. The latest "ab initio" quantum mechanical methods are used to identify the decisive reaction pathways and to determine the corresponding rate parameters. Together with models to describe the convective and diffusive transport of mass, momentum and energy and the thermal radiation, the deposition in a reactor can be described under real operating conditions. Based on the experience gained in the last project phase and with the help of process simulation, a new reactor is also being designed that is optimally suited for quantitative CVD experiments. The direct comparison between measured and calculated growth rates and processes allows the validation of the theoretical approach, also with regard to the application to other systems. As a result of the project, the aim is to obtain for the first time a complete picture of all processes during the MOVPE process of a non-trivial single-component precursor at the molecular-cooler level.