A study was conducted on the reliability aspects of thin reoxidized nitrided oxides (ROXNOX), as an alternative gate dielectric to thermal silicon dioxide in submicron metal oxide semiconductor (MOS) devices. MOS capacitors, with ROXNOX gate oxides of thicknesses ranging from 7 to 10 nm, were subjected to constant voltage stressing. The density and distribution of the traps inside of the insulator were determined before and after high field stressing. The ROXNOX exhibited a high initial trap density in contrast to the normally low initial trap density in oxides. The trap generation rate, after stressing, was considerably lower than that measured in thermal oxides. The low-level leakage currents were higher in the ROXNOX than in thermal oxides, and their voltage and fluence dependences after stressing were different. Leakage currents under low fields in unstressed ROXNOX were composed of a transient component and an ohmic de component. The de resistivity of the ROXNOX increased as the thickness increased. A model was proposed to explain the mechanism of low field conduction in the ROXNOX.