IMPROVEMENT OF HOT-CARRIER RELIABILITY WITH DEUTERIUM ANNEALS FOR MANUFACTURING MULTILEVEL METAL DIELECTRIC MOS SYSTEMS/

This paper discusses new experimental findings critical for process in tegration of deuterium post-metal anneals to improve channel hot carri er reliability in manufacturing multilevel metal CMOS integrated circu its. Detailed account of the deuterium process optimization experiment s varying temperature, time, and ambient is given, Specifically, the f irst demonstration of the large hydrogen/deuterium isotope effect for multilevel metal/dielectric MOS systems is reported. Previous accounts of the isotope effect had been limited to CMOS structures with one-le vel of dielectric/metal and to about a 10 fold improvement in reliabil ity. Deuterium, instead of hydrogen is introduced via an optimized pos t-metal anneal process to achieve a 50-100 fold improvement in transis tor channel hot carrier lifetime. The benefits of the deuterium anneal are still observed even if the post-metal anneal is followed by the f inal SIN cap wafer passivation process. It is concluded that the deute rium post-metal anneal process is suitable for manufacturing high perf ormance CMOS products and fully compatible with traditional integrated circuit processes.