Preparation of Strontium Titanate Film by Low Pressure Chemical Vapor Deposition

Abstract

Strontium titanate (SrTiO3; STO) film was prepared by low-pressure chemical vapor deposition (CVD). STO thin film without other crystals could be prepared on a silicon substrate under specific conditions, i.e., Xi = 0.81 at 823 K, 0.62 < Xi < 0.70 at 873 K, 0.67 < Xi < 0.78 at 973 K, and Xi = 0.85 at 1073 K. STO, titanium oxide (TiO2), and strontium-containing films (e.g., SrX; SrCO3, and SrSiO3) grown by CVD at high temperatures (> 873 K) had poor step coverage. However, at low temperatures (< 723 K), although TiO2 and SrX single-component films had poor step coverage, Sr-Ti composite film, which was amorphous, could fill in a microscale trench. At low temperatures, the surface reaction of the precursor used to prepare composite oxide is likely slower than that of the precursor for preparing TiO2 and SrX films.