Studies of the thickness dependence on stress‐induced leakage current (SILC) have been performed in the thickness range of 41 to 87 A˚ for N2O‐annealed and O2‐grown oxides. N2O‐annealed oxide shows significantly reduced SILC leakage currents. Furthermore, SILC currents were found to increase with decreasing oxide thickness, as reported earlier. However, a ‘‘turn‐around’’ effect at ∼50 A˚ has been observed in these films. SILC currents begin to decrease when oxide thickness is scaled below 50 A˚. This turn‐around effect can be explained using the trap‐assisted tunneling model. For thicknesses equal or less than 41 A˚, defect‐related current and direct tunneling current become dominant over SILC current. Our results indicated that for N2O‐based oxides in the ultrathin thickness regime, stress‐induced leakage currents become less significant. ©1995 American Institute of Physics.