Electrical and reliability characteristics of oxynitride gate dielectric grown by diluted steam rapid thermal oxidation and annealed in nitric oxide

The rapid thermal processing (RTP) system using in situ steam generation (ISSG) was employed to grown 30 إ gate oxides in this study. Experimental results indicate that oxides grown by diluted steam rapid thermal oxidation exhibit significant reduction in gate leakage current, increase in breakdown field, current derivability and device reliability, as compared to conventional furnace-grown wet oxides. The post-annealing effects of ISSG oxide in N2 and nitric oxide (NO) ambient were examined. It was found that the sample with post-annealing in NO ambient shows less charge trapping, higher charge-to-breakdown, higher electron mobility and smaller device degradation under channel hot-carrier stress. This is attributed to the improvement of structural transition layer by the incorporation of nitrogen near and at Si/SiO2 interface during NO annealing.