Ultrathin furnace reoxidized nitrided oxide gate dielectrics for extreme submicrometer CMOS technology

The electrical characteristics of ultrathin reoxidized nitrided oxide (ROXNOX) gate dielectrics grown in a low pressure furnace at 850 degrees C have been investigated extensively. Experimental results show that a 1000 degrees C rapid thermal annealing (RTA) process after gate dielectric growth and polysilicon deposition can significantly reduce the levels of fixed charge and interface states in ROXNOX dielectrics. It has been demonstrated that a 45 AA ROXNOX gate dielectric can successfully block boron diffusion into the device channel region over a wide range of dopant activation temperatures and times. Channel mobilities for ROXNOX gate NMOS and PMOS devices are increased after the RTA process due to the improvement in dielectric quality, while the enhanced device reliability under hot carrier stress is maintained.<
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