Growth and dielectric characterizations of zinc stannate thin films deposited by RF magnetron sputtering

Abstract

The microstructures and dielectric properties of zinc stannate (Zn₂SnO₄) thin films were investigated. Zn₂SnO₄ thin films were deposited on p-Si (1 1 0) substrate using the radio frequency magnetron sputtering with various Ar/(Ar + O₂) ratios. The X-ray diffraction patterns of Zn₂SnO₄ thin films revealed that Zn₂SnO₄ is the main crystalline phase and is accompanied by small amounts of ZnSnO₃ as second phase. The Zn₂SnO₄ thin films deposited at Ar/(Ar + O₂) ratio of 1.0 showed a strong (3 1 1) preferred orientation. The grain size, thickness, and surface roughness of Zn₂SnO₄ thin films increased as the Ar/(Ar + O₂) ratio increased. Dielectric constants (${\epsilon }_r$) of 22-202 and loss factor of 0.22-0.41 of Zn₂SnO₄ thin films were measured at 1 MHz with Ar/(Ar + O₂) ratio in the range of from 0.4 to 1.0. The leakage current density increased from $6.8\times {10}^{-7}$ to $3.2\times {10}^{-4}$ A/mm² of Zn₂SnO₄ thin films applied at 0.1 MV/cm as Ar/(Ar + O₂) ratio increased from 0.4 to 1.0.

Keywords:

• Thin films
• sputtering
• dielectric properties