EFFECT OF BULK MICRODEFECTS INDUCED IN HEAT-TREATED CZOCHRALSKI SILICON ON DIELECTRIC-BREAKDOWN OF THERMAL SIO2-FILMS

We examine the effect of bulk microdefects (BMD) intentionally introduced in Czochralski silicon substrates by heat treatment on the dielectric breakdown of thermally grown SiO2 films. Transmission electron microscope observations reveal that the BMD consist of oxygen precipitates, perfect dislocation loops, and faulted dislocation loops. When the BMD are incorporated into the SiO2 film during thermal oxidation, an apparent decrease in the breakdown field is observed. The size of the oxygen precipitates has a clear relationship with the breakdown field: larger oxygen precipitate causes greater degradation. The dislocation loops are unrelated to the breakdown field.