Improvement of electrical properties of MOCVD HfO2 by multistep deposition

Abstract

A multistep metallorganic chemical vapor deposition (MOCVD) technique of HfO2 gate dielectric and its electrical properties are reported. This technique involves steps of "deposition followed by postdeposition annealing" of HfO2 in which each step is repeated on the previously deposited and annealed HfO2. Our experiment demonstrates significant reduction of gate leakage current after high-temperature annealing for HfO2 deposited using a multistep deposition technique as compared to conventional single-step deposition. This improvement is attributed to offset of the grain boundaries and pinholes from one layer to another in a multistep deposited HfO2 which eventually leads to blockage of leakage current path. (C) 2003 The Electrochemical Society.