Preparation and Characterization of ZST Films for CMOS Applications

Abstract

Zirconium tin titanate (Zr, Sn)TiO₄ (ZST) thin films have been deposited at ambient temperature by dc magnetron sputtering from individual titanium, zirconium and tin metal targets on platinized silicon substrates. The present study demonstrates the possibility of growing zirconium tin titanium oxide films in 100% pure dc oxygen plasma. Films having thickness of the order of 450 nm have been grown starting from the metallic Zr, Ti and Sn targets in pure oxygen plasma. The grains as observed from atomic force microscope images are found to be a mixture of spherical and triangular geometry. The maximum value of dielectric constant and loss are found to be 53.7 and 0.0075 (at 5 MHz) for the films deposited at 40% Oxygen Mixing Percentage (OMP). The magnitude of current density and the breakdown field strength of the ZST films deposited at 40% OMP are found to be 9.72 × 10⁻⁷ Amp/cm² and 62.5 KV/cm respectively. The effect of processing parameters on structural, microstructural, optical, dielectric and electrical properties of the (Zr,Sn)TiO₄ films have been investigated.

Keywords:

• ZST thin films
• sputtering
• optical
• electrical
• dielectric properties

Acknowledgment

DP acknowledges Dr. Kothari's postdoctoral fellowship from UGC and KS acknowledges CSIR for SRF. Facilities provided by the ISRO, UGC, UGC-CAS, DST-FIST and DST Nanocenter are gratefully acknowledged.