Grain boundary diffusion of aluminum in polycrystalline silicon films

Grain boundary diffusion of Al in poly‐Si films has been measured by an Auger sputter profiling technique in a temperature range of 350–425 °C. The Al atoms were observed to diffuse through Si grain boundaries, then accumulated near a poly‐Si/SiO2 interface. By concentrating on the initial stage of diffusion, the diffusion problem was analyzed using a simple model in which a steady‐state flux of Al though Si grain boundaries is accumulated by an effectively infinite sink at the poly‐Si/SiO2 interface. Auger measurements yielded quantitative information regarding the concentration gradient in the middle of the poly‐Si layer and the amount of accumulation near the poly‐Si/SiO2 interface. From this information, the grain boundary diffusion coefficient of Al in Si Db was determined. The temperature dependence of Db fits an Arrhenius‐type relation with D°b =1.3×107 cm2/s and Qb =2.64 eV. The measured activation energy was found to be consistent with that of the grain boundary diffusion of P and B as well as th...

[1]  L. Tanner.  Physical properties of TiBeSi glass ribbons , 1978 .

[2]  G. Gurp,et al.  Diffusion‐limited Si precipitation in evaporated Al/Si films , 1973 .

[3]  F. Trumbore,et al.  Solid solubilities of impurity elements in germanium and silicon , 1960 .

[4]  E. D. Hondros,et al.  Use of a “BET” analogue equation to describe grain boundary segregation , 1973 .

[5]  H. Queisser,et al.  Diffusion along Small-Angle Grain Boundaries in Silicon , 1961 .

[6]  Archibald L. Fripp,et al.  Thin Films—Interdiffusion and Reactions , 1979 .

[7]  R. N. Tucker,et al.  Diffusion of Impurities in Polycrystalline Silicon , 1972 .

[8]  Akio Hiraki,et al.  Low-Temperature Migration of Silicon in Metal Films on Silicon Substrates Studied by Backscattering Techniques , 1972 .

[9]  R. Blanchard,et al.  Boron diffusion in polycrystalline silicon layers , 1975 .

[10]  J. Hwang,et al.  Measurement of grain‐boundary diffusion at low temperatures by the surface accumulation method. I. Method and analysis , 1979 .

[11]  J. K. Howard,et al.  Auger study of preferred sputtering on binary alloy surfaces , 1976 .

[12]  Kunio Nakamura,et al.  Low‐temperature diffusion of Al into polycrystalline Si , 1977 .

[13]  J. Hwang,et al.  Measurement of grain‐boundary diffusion at low temperature by the surface‐accumulation method. II. Results for gold‐silver system , 1979 .

[14]  H. Sankur,et al.  Diffusivity and Solubility of Si in the Al Metallization of Integrated Circuits , 1971 .

[15]  Takuzo Ogawa,et al.  The Deformation of Polycrystalline‐Silicon Deposited on Oxide‐Covered Single Crystal Silicon Substrates , 1977 .

[16]  K. Tu,et al.  Diffusion of arsenic along dislocations in epitaxial silicon films , 1975 .

[17]  P. Ho,et al.  Deconvolution method for composition profiling by Auger sputtering technique , 1976 .