Electrical and structural characteristics of thin nitrided gate oxides prepared by rapid thermal nitridation

The electrical and structural characteristics of thin nitrided thermal oxides prepared by rapid thermal nitridization (RTN) have been studied. Nitridization times vary between 3 s and 5 min in an ammonia ambient. Films have been characterized using Auger, ellipsometry, C-V and I-V techniques. RTN allows to form surface nitridized oxides (NO), surface-interface nitridized oxides (NON), and oxinitrides. The effective refractive index varies between 1.45 to 1.7. Catastrophic breakdown voltages of RTN oxides are up to 3 time higher than thermal oxides. Optically and electrically determined permitivities of RTN films agree closely. RTN induced flat band shifts for times shorter than 10 s at 1150 C and 100 A oxides are monotonic with the nitridization time and explained by positive fixed charges with a density of the order of 1 1011 cm
^-2
without significant changes in the fast interface state density. RTN oxides show an excellent potential for submicron MOS technologies.