Evaluation of microscopic structural randomness in SiO2 by analysis of photoluminescence decay profiles

Abstract

Microscopic structural randomness in SiO2, a typical electrical insulating material, was evaluated by observing the decay profile of the photoluminescence due to oxygen vacancies (≡Si‐Si≡). As samples with different degrees of randomness, an ion‐implanted thermal SiO2 film, SiO2 films formed by plasma‐enhanced chemical vapor deposition of tetraethoxysilane with and without doped fluorine, a buried oxide film prepared by SIMOX (separation by ion‐implanted oxygen), and a bulk silica glass prepared by the soot‐remelting method were tested. By analyzing the decay profile with a stretched exponential function, it was found that the deviation of the decay profile from a single exponential function is larger in the samples whose infrared absorption properties and HF etch rate suggest greater structural randomness. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119 (3): 1–6, 1997