Formation of high quality ultrathin oxide/nitride (ON) stacked capacitors by in situ multiple rapid thermal processing [DRAM cells]

High quality, ultrathin (<30 /spl Aring/) SiO/sub 2//Si/sub 3/N/sub 4/ (ON) stacked film capacitors have been fabricated by in situ rapid-thermal multiprocessing. Si/sub 3/N/sub 4/ film was deposited on the RTN-treated poly-Si by rapid-thermal chemical vapor deposition (RTCVD) using SiH/sub 4/ and NH/sub 3/, followed by in situ low pressure rapid-thermal reoxidation in N/sub 2/O (LRTNO) or in O/sub 2/ (LRTO) ambient. While the use of low pressure reoxidation suppresses severe oxidation of ultrathin Si/sub 3/N/sub 4/ film, the use of N/sub 2/O-reoxidation significantly improves the quality of ON stacked film, resulting in ultrathin ON stacked film capacitors with excellent electrical properties and reliability.<
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