Atomic Layer Deposition of Manganese Silicate, Molecular Layer Deposition of Polyimide and Their Applications

Abstract

A convenient and highly controllable atomic layer deposition (ALD) of manganese silicate (MnSixOy) thin film method is presented in this thesis. This method can achieve high conformal films on any three-dimensional structures. ALD MnSixOy thin film can serve as a diffusion barrier for Cu without subsequent annealing. The elemental distribution is uniform. Its efficiency as the oxygen and water diffusion barrier for copper is confirmed with experiments. These properties are promising for applications in the semiconductor industry. A polyimide thin film deposited by molecular layer deposition (MLD) with pyromellitic dianhydride (PMDA) and ethylenediamine (EDA) precursors is also demonstrated in this work. This is an exceptionally flexible and electrical insulating organic film with high thickness controllability. This method can also achieve highly uniform coverage on complex structures, such as nanowires. To make hybridized polyimide, we used PMDA-EDA cycles to create linear polyimide layers, along with one PMDA-DETA (ethylenediamine) cycle to create a branched polyimide layer. In this MLD process, each MLD super-cycle consists of several cycles of forming linear polyimide (PMDA-EDA process) and one cycle of forming branched polyimide (PMDA-DETA process). This branched and cross-linked polymer films potentially have some improved properties compared to normal linear polymer films. Higher thermal stability, larger film density, better mechanical strength and elasticity may be achieved because of more branches and cross-linkers.