A technique was proposed for the simultaneous diffusion of B and P on opposite sides of a wafer. The solid dopant sources which were used in this method could be tailored so as to produce a wide range of B diffusion profiles, for a given thermal diffusion cycle. The uniformity of the sheet resistance across a 49cm2 area was often greater than 95%. A unique feature was that the resultant diffusion glass was extremely thin.

T.Krygowski, A.Rohatgi: Journal of the Electrochemical Society, 1997, 144[1], 346-52