Study of the effect of substrate bias on the electrical properties of sputtered HfO2 thin film deposited on silicon substrate

Abstract

PurposeHfO2 has emerged as the most promising high k dielectric for an alternative gate material. As‐deposited HfO2 thin films have large number of defects resulting in increased oxide charge and leakage current. Film deposition condition plays an important role. This paper investigates the effect of sputtering voltage, bias sputtering and post deposition thermal annealing.Design/methodology/approachThe microstructure of the film is examined by AFM. The I‐V and C‐V characteristics is evaluated from Al‐HfO2‐Si capacitor structures and the effect of processing conditions is studied. The experimental results are reported and discussed for improving film properties.FindingsIt is found that applying substrate bias during film deposition improves interface and reduce leakage current and oxide charges.Originality/valueThe paper studies the effect of deposition voltage and thermal annealing on thin film deposition of HfO2 by rf sputtering.