Low interface state density SiO2 deposited at 300 °C by remote plasma-enhanced chemical vapor deposition on reconstructed Si surfaces

Abstract

A 300 °C process has been used to deposit high-quality SiO2 on Si. The process is based on remote plasma-enhanced chemical vapor deposition. In this process excited species from a remote oxygen plasma interact with silane in the deposition zone. A hydrogen plasma is used to clean the silicon surface in situ just prior to deposition. After a 400 °C post-metallization anneal, interface-state densities as low as 3.7×1010 cm−2 eV−1 were measured with a fixed charge density of 2×1011 cm−2. The films exhibited good breakdown integrity, sustaining fields of 9–10 MV cm−1. The Si/SiO2 interface-state density directly correlates with the quality of reflection high-energy electron diffraction patterns from the silicon surface just prior to oxide deposition.