Deposition Mechanism and Electrical Property of CeO_2 Thin Films by MOCVD with H_2O Introduction

摘要

Cerium dioxide (CeO_2) thin films are prepared by means of the metal organic chemical vapor deposition (MOCVD) using tetrakis (3-methyl-3-pentoxy) cerium with and without H_2O vapor introduction. A large amount of H_2O (more than 2 sccm) acts as an oxidant and as a result the deposition rate increases by up to four times at the deposition pressure of 2.0 Pa, leading to the temperature independence of the deposition rate. At the low deposition temperature of 270 °C, a small amount of H_2O (0.1-0.2 sccm) suppresses the deposition because of its preferential occupation of the surface sites. The CeO_2 film annealed at 600 °C in the oxidizing ambient shows steep C-V characteristics with no flat band voltage shift nor hysteresis.