Impurity Redistribution Processes in Epitaxial Silicon Layers

Impurity redistribution processes occurring during the epitaxial growth of silicon layers have been investigated using radiotracer techniques. The final impurity profiles obtained have been measured by the capacitance‐voltage technique and the results compared with theoretically computed profiles. It has been shown that the occurrence of the previously postulated etch‐back mechanism is unlikely, and that all of the redistributed impurity can be accounted for in terms of solid‐state diffusion from the front of the substrate and outdiffusion from the rear. Certain anomalous diffusion rates have been observed in the case of phosphorus doped substrates.