Effects of N2O anneal and reoxidation on thermal oxidecharacteristics

The effects of post-oxidation N₂O anneal on conventional thermal oxide are studied. The oxide thickness increase resulting from N₂O anneal is found to be self-limiting and insensitive to initial oxide thickness, which makes the thickness of the resulting oxide easy to control. The N₂O anneal leads to increased resistance against injection-induced interface-state generation and to reduced hole trapping. No further quality improvement is found when the N₂O-annealed oxide is subject to an additional reoxidation. This finding confirms that nitrogen incorporation in the absence of hydrogen is responsible for improving the quality of the conventional oxides