Evolution of Interdiffused Gaussian-Shape Nanolayer in Au-Si(111) System at Ambient Condition
Evolution of interdiffused Gaussian-shape nanolayer of Au-Si, formed due to diffusion of Au into Si(111) substrate at ambient conditions, depends strongly on the Si surface pretreatment/passivation conditions. Negligible diffusion in the Au-OSi(111) sample, confirms the strong barrier action of the oxide-layer against diffusion, while large diffusion in the Au-HSi(111) sample compared to that in the Au-BrSi(111) sample suggests that the H-passivated Si(111) surface is more stable. This nature of the Au-Si(111) system is qualitatively similar to that of the Au-Si(001) system but it differs quantitatively. The size, electronegativity and bond-energy of the passivating elements and the number of dangling bonds on the Si surface influence the instability of the Si surface. This instability, parameterized by growth-time of oxide layer alone, can be utilized to tune the amount of diffusion into the sub-surface Si region. The distribution of growth-time and fractional passivated area, which are related to the improper Si surface passivation, are against such control and needs perfection.
Andreas Öchsner, Graeme E. Murch, Ali Shokuhfar and João M.P.Q. Delgado
J.K. Bal and S. Hazra, "Evolution of Interdiffused Gaussian-Shape Nanolayer in Au-Si(111) System at Ambient Condition", Defect and Diffusion Forum, Vols. 297-301, pp. 1133-1139, 2010