SIMS STUDY OF RAPID NITRIDATION OF SILICON DIOXIDE THICK-FILMS IN AN AMMONIA AMBIENT

Thick silicon dioxide films of 1.5 mu m thickness have been nitrided a t temperatures of 700 degrees C and 800 degrees C for 30, 60 and 300 s in a lamp-heated furnace at atmospheric pressure using ammonia. A mec hanism of interstitial diffusion of ammonia, together with its reactio n with silica, is suggested to explain the exponential shape of the ni trogen profiles in the nitrided 1.5 mu m silica films. From this analy sis we have extracted the values of the effective reaction coefficient k and of the effective diffusion coefficient D*, both correlated by x(o), the exchange length for the exchange of oxygen atoms by imine ra dicals.