Skip to Main Content
The effects of postdeposition anneal of chemical vapor deposited silicon nitride are studied. The Si3N4 films were in situ annealed in either H2(2%)/O2 at 950/spl deg/C or N2O at 950/spl deg/C in a rapid thermal oxidation system. It is found that an interfacial oxide was grown at the Si3N4/Si interface by both postdeposition anneal conditions. This was confirmed by thickness measurement and X-ray photoelectronic spectroscopy (XPS) analysis. The devices with H2(2%)/O2 anneal exhibit a lower gate leakage current and improved reliability compared to that of N2O anneal. This improvement is attributed to a greater efficiency of generating atomic oxygen in the presence of a small amount of hydrogen, leading to the elimination of structural defects in the as-deposited Si3N4 film by the atomic oxygen. Good drivability is also demonstrated on a 0.12 μm n-MOSFET device.