Very lightly nitrided oxide gate MOSFETs for deep-sub-micron CMOS devices

Abstract

The characteristics and reliability of the nitrided oxide gate n- and p-MOSFETs with less than 1 atom% nitrogen concentration gate films were investigated in detail. These very light nitridations were accomplished using NH/sub 3/ gas at low temperatures from 800 degrees C to 900 degrees C. The low nitrogen concentrations, such as 0.13 atom% were obtained by SIMS and AES (Auger electron spectroscopy) measurements. The optimum nitrogen concentration region for the deep-sub-micron device is discussed. It was shown that, with the 0.5 atom% nitrogen concentration, good drivability and good hot carrier reliability were attained at the same time, and they were equivalent to those of the oxynitride gate MOSFETs using N/sub 2/O gas. The suppression of boron penetration is also discussed.<>