Effects of post-deposition anneal on the electrical properties ofSi3N4 gate dielectric |
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Authors: | Lin W.H. Pey K.L. Dong Z. Choi S.Y.-M. Zhou M.S. Ang T.C. Ang C.H. Lau W.S. Ye J.H. |
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Affiliation: | Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore; |
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Abstract: | 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°C or N2O at 950°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 Si3N 4 film by the atomic oxygen. Good drivability is also demonstrated on a 0.12 μm n-MOSFET device |
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