Highly reliable SiO/sub 2//Si/sub 3/N/sub 4/ stacked dielectric on rapid-thermal-nitrided rugged polysilicon for high-density DRAM's

Experimental results are presented demonstrating that by using rapid thermal nitridation (RTN) of rugged poly-Si surface prior to Si/sub 3/N/sub 4/ deposition, the quality and reliability of reoxidized Si/sub 3/N/sub 4/ dielectric (ON dielectric with an effective oxide thickness of about 35 AA) can be significantly improved over ON films on rugged poly-Si without RTN treatment. These improvements include significantly reduced defect-related dielectric breakdown, 10/sup 3/ * increase in TDDB lifetime, lower leakage current, and suppressed electron-hole trapping and capacitance loss during stress.<
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