Ethanol‐Addition‐Enhanced, Chemical Vapor Deposited Tantalum Oxide Films from Ta ( OC 2 H 5 ) 5 and Oxygen Precursors

Abstract

An innovative chemical vapor deposition (CVD) technique of film from including ethanol and oxygen precursors is demonstrated in this paper. High deposition rate of approximately 10 nm/min is obtained by employing including ethanol and oxygen precursors at 350°C. Temperature‐programmed decomposition analysis shows that decomposition of ethanol, adsorbed on the film surface, into hydrogen and aldehyde begins at 250°C. These results suggest that film plays a role as a catalyst for dehydrogenation of ethanol. Under oxygen ambient, water seems to be easily generated on the surface by reaction between the hydrogen and oxygen. Hydrolysis of ethoxide on the surface promotes deposition of film. Carbon concentration included in the as‐deposited film can be remarkably reduced by the plasma oxygen annealing at 350°C. Combination of the CVD at 350°C and plasma‐activated oxygen annealing at 350°C provide favorable insulative properties for future dynamic random access memories and make it possible to form the film on the storage node while preventing oxidation of the storage node.