Published online by Cambridge University Press: 21 February 2011
Molybdenum contamination has been detected in silicon epitaxial layers and substrate wafers after processing in any one of several epitaxial silicon reactors. Greatly reduced minority carrier diffusion lengths and lifetimes are consistent with Mo concentrations measured by DLTS in the 1012 and 1013 cm−3 ranges. Depth profiling of diffusion length and the Mo deep level show much greater penetration than expected from previous reports of Mo as a slow diffuser. The data indicate a lower limit of 10−8 cm2/sec for the diffusion coefficient of Mo in silicon at 1200°C, consistent with high diffusivities measured for other transition metals.