Effect of initial precursor concentration on TiO2 thin film nanostructures prepared by PCVD system

Abstract

TiO2 thin film was prepared on Si substrate by plasma chemical vapor deposition (PCVD) system and the morphologies of TiO2 thin film were controlled by adjusting the initial precursor concentration. As the initial titanium tetra-isopropoxide (TTIP) concentration increases in PCVD reactor, the shapes of TiO2 particles generated in PCVD reactor change from the spherical small-sized particles around 20 nm and spherical large-sized particles around 60 nm to aggregate particles around 100 nm. The TiO2 particles with different shapes deposit on the substrate and become the main building blocks of resulting TiO2 thin film. We observed the TiO2 thin film with smooth morphology at low initial TTIP concentration, granular morphology at medium initial TTIP concentration, and columnar morphology at high initial TTIP concentration. It is proposed that we can prepare the TiO2 thin film with controlled morphologies in one-step process just by adjusting the initial precursor concentration in PCVD.