Understanding, and thereby preventing or eliminating, the causes of gate-oxide breakdown is among the primary concerns in MOS technology. Specifically, the effects of preoxidation cleaning need to be understood so that these processes can be optimized, and conditions affecting the oxidation process itself need to be taken into consideration when chambers are upgraded to meet increasingly stringent requirements. In the research reported in this article, the influence on gate-oxide integrity of modified RCA cleans was investigated. Based on the experimental results, a new SC-1 formulation and the elimination of the SC-2 step under certain conditions are proposed. The effect of the time waited between cleaning and oxidation furnace loading was also assessed. Finally, furnace loading and ramp-up in an inert ambient was studied, and it was found that oxygen should be added to the inert gas to prevent wafer surface roughening.
|Original language||English (US)|
|Number of pages||10|
|State||Published - May 1992|
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