Substrate temperature influenced ZrO ₂ films for MOS devices

Abstract

The effect of substrate temperature on the direct current magnetron‐sputtered zirconium oxide (ZrO 2 ) dielectric films was investigated. Stoichiometric of the ZrO 2 thin films was obtained at an oxygen partial pressure of 4.0 × 10 −2 Pa. X‐ray diffraction studies revealed that the crystallite size in the layer was increased from 4.8 to 16.1 nm with increase of substrate temperature from 303 to 673 K. Metal‐oxide‐semiconductor devices were fabricated on ZrO 2 /Si stacks with Al gate electrode. The dielectric properties of ZrO 2 layer and interface quality at ZrO 2 /Si were significantly influenced by the substrate temperature. The dielectric constant increased from 15 to 25, and the leakage current density decreased from 0.12 × 10 −7 to 0.64 × 10 −9 A cm −2 with the increase of substrate temperature from 303 to 673 K.