The diffusion of boron into silicon has been investigated over a temperature range of 1050°C to 1350°C using an open-tube vapor-solid diffusion technique at atmospheric pressure. A p-n junction method of measuring the diffused layer was used to determine the diffusion constant. Lower diffusivities and a somewhat lower activation energy, (ΔH=81 kcal) were obtained than those reported previously. The difference is attributed to variation of diffusivity with surface concentration and is discussed on the basis of field-aided diffusion theory.

Silicon epitaxial layers of good quality have been deposited on silicon substrates by the pyrolysis of silane at low temperatures. Studies to minimize the degradation of the impurity profile of an epitaxial silicon layer caused by various sources or processes are reported. Auto doping and system doping during deposition have been minimized by using techniques such as sealing the backsides of the substrates, sealing the susceptor, and using two-temperature cycle depositions. Impurity profiles of the layers deposited by the above methods are compared with the profiles of the layers obtained from more conventional deposition conditions.

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