Measurements were made of the Si diffusivity in film samples by using isotopically enriched 28Si dioxide layers which permitted relatively low 30Si concentration measurements to be performed by using secondary ion mass spectrometry. Two types of experiment were performed. An excess of 30Si atoms was introduced into a stoichiometric isotopically pure dioxide layer by using ion implantation or a pre-deposition technique. The experiments were representative of any situation in which excess Si atoms were introduced into dioxide layers during Si processing. The estimated diffusivity values were significantly higher than previously reported values for Si diffusion in a stoichiometric oxide, and were closer to reported values for excess Si diffusion in an oxide. The results could be described by:

D (cm2/s) = 1.378 x 100 exp[-4.74(eV)/kT]

D.Tsoukalas, C.Tsamis, P.Normand: Journal of Applied Physics, 2001, 89[12], 7809-13