Characteristics of Tantalum Carbo-nitride Thin Films Deposited with Atomic Layer Deposition Process

Abstract

Tantalum carbo-nitride (TaCN) thin films were deposited on SiO2 surface with the plasma enhanced atomic layer deposition (PEALD) and thermal atomic layer deposition using tert-butylimido-tris (diethylamido)-tantalum (TBTDET) and reactive gas such as hydrogen and ammonia. It was confirmed that the film was a mixture of TaC, TaN, Ta3N5 and Ta2O5 with oxide phase formed from the post-deposition uptake of oxygen from the air. It was shown that electrical properties of TaCN film were affected by the phase composition in the film. Effect of the process parameters such as deposition temperature and plasma power was studied and their effect on phase composition and electronic properties was evaluated. The uptake of oxygen after deposition was about 10 atomic % with the PEALD process and about 30 atomic % with thermal ALD process and it is believed that denser film could be obtained with plasma.