Evolution of the microstructure in titanium dioxide films during chemical vapor deposition

摘要

Chemical vapor deposition (CVD) provides fabrication of high purity conformal layers of titanium dioxide with different structure for various applications. In this work CVD of titania layers from titanium tetraisopropoxide (TTIP) and oxygen at 1 kPa and in the substrate temperature range T_s = 300-500 ℃ was studied. It was found that growth of TiO_2 is a non-stationary process. Two periods of time characterized by different deposition rates were observed. Formation of amorphous TiO_2 occurs at the initial period of the deposition process whereas polycrystalline titania with anatase crystal structure is deposited at the second period. Substrate temperature determines degree of crystallinity, texture, and microstructure of the deposited titania layers.