Title :
Effects of post-deposition anneal on the electrical properties of Si3N4 gate dielectric
Author :
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.
Author_Institution :
Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore
fDate :
3/1/2002 12:00:00 AM
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/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.
Keywords :
CVD coatings; MOSFET; X-ray photoelectron spectra; annealing; dangling bonds; dielectric thin films; leakage currents; semiconductor device breakdown; semiconductor device reliability; semiconductor-insulator boundaries; silicon compounds; 0.12 micron; 950 degC; CVD Si/sub 3/N/sub 4/ films; H/sub 2/; H/sub 2/-O/sub 2/; N/sub 2/O; N/sub 2/O anneal; O/sub 2/; O/sub 2/ anneal; Si/sub 3/N/sub 4/ gate dielectric; Si/sub 3/N/sub 4/-Si; Si/sub 3/N/sub 4//Si interface; TDDB; X-ray photoelectronic spectroscopy; XPS analysis; chemical vapor deposited Si/sub 3/N/sub 4/; gate leakage current; in situ annealed films; interfacial oxide; n-MOSFET device; postdeposition annealing; rapid thermal oxidation system; reliability; structural defects elimination; thickness measurement; time-dependent dielectric breakdown; Chemicals; Hydrogen; Leakage current; MOSFET circuits; Oxidation; Rapid thermal annealing; Semiconductor films; Silicon; Spectroscopy; Thickness measurement;
Journal_Title :
Electron Device Letters, IEEE
