Cesare Clementi

The impact of F contamination induced by the process on the gate oxide reliability

The effects of F contaminants introduced by the CVD WSi2 deposition and diffused to the gate oxide interfaces by the thermal treatment performed during the process have been analyzed. High field stresses showed a degradation of the quality of the oxides contaminated by fluorine, but decreasing the stress field below a critical value of 10.5 MV/cm no more effect of fluorine on the gate oxide reliability was detectable.

Influence of charge trapping on oxide scaling down

Abstract The aim of this work is the characterization, in terms of trapped charge and charge to breakdown, of the quality of an oxide with reduced thickness. A comparison between two evaluation methods, the widely used exponentially ramped current stress (ERCS) and the constant current stress (CCS), is established obtaining contradictory results. A measurement of the charge trapped in the oxide bulk is performed by sensing the modification of the Fowler–Nordheim barrier under constant current stress. Using this technique it is possible to correlate the charge trapping characteristics with the charge to breakdown and to explain the inconsistencies.

Feasibility of steam tunnel oxide for advanced non volatile memories

Abstract In order to reduce dopant diffusion to obtain device scaling, a decrease of any thermal treatment is required. Therefore, to substitute dry thermal oxides for tunnel application in Flash Memories, the possibility of using steam oxides grown at low temperatures was studied, considering, in addition, scaling of these oxides for future generations. Results concerning oxide reliability and charge trapping for elementary structures are presented and correlated with device performance.