In this paper, stress-induced leakage current (SILC) is studied in ult
rathin (approximately 50 angstrom) gate oxides grown in N2O or O2 ambi
ent, using rapid thermal processing (N2O oxide or control oxide, respe
ctively). MOS capacitors with N2O oxides exhibit much suppressed SILC
compared to control oxide for successive ramp-up, constant voltage dc,
and ac (bipolar and unipolar) stresses. The mechanism for SILC is dis
cussed and the suppressed SILC in N2O oxide is attributed to the suppr
essed interface state generation due to the nitrogen incorporation at
the Si/SiO2 interface during N2O oxidation.