Gate Oxide Defects in MOSLSIs and Octahedral Void Defects in Czochralski Silicon

The origin of insulator defects in gate oxides and poly-oxides was thoroughly investigated. We clarified that octahedral void defects originating in a Czochralski silicon substrate are responsible for gate-oxide defects and that polyhedral void defects produced during annealing or oxidation are responsible for defects in insulators on poly-silicon. These are expected to be the principal defects affecting the yield and reliability of next-generation metal-oxide-silicon large-scale integrated-circuits or flash memories. In addition, defects in the buried oxides of a silicon-on-insulator substrate were also examined. Octahedral defects or polyhedral defects were observed just under the buried-oxide defects. Octahedral defects and polyhedral defects may be common in standard metal-oxide-silicon large-scale integrated-circuits, flash memories, and silicon-on-insulator substrates.