This study introduces a new, simple, and viable LPCVD technique based on the injection of miscible liquid precursors. The preparation of BPSG films from liquid mixtures of TEOS, TMB, and TMP is used here as a prime example for implementing this concept. The relationship between starting solution composition and resulting film composition is investigated to provide guidelines for achieving desired stoichiometries. Variations in growth rate and composition are examined to assess the relative effects of deposition temperature, total pressure, solution composition, and injection rate. At the high boron and phosphorus levels (4 weight percent), the reaction chemistry associated with the use of TMP is seen to produce severe depletion effects. At optimum deposition conditions, select properties of BPSG films are investigated. The results indicate high compositional uniformity within the film, a dielectric constant value in close agreement with that of thermally grown, SiO2, conformal step coverage even in the case of severe aspect ratios, and desirable flow profiles at temperatures and phosphorus concentrations significantly lower than those being currently achieved with phosphosilicate glass films.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry