Abstract
Control of sheet resistance and surface concentration subsequent to diffusion was achieved by controlling the doping level in the oxide. The ternary system diethylphosphate (DEP)‐nitrite‐tetrahydrofurfuryl alcohol was found suitable for producing doped oxide films that can be used for base or collector diffusions. The correlation between concentration of DEP in the solution and amount of phosphorus incorporated into the oxide was determined by tracer experiments with P‐32 tagged DEP. The more dilute solutions were found to be sensitive to temperature and current density during anodization. Incorporation of alkali ions into the anodic oxide film can be avoided if the number of anodizations in the same batch of solution is limited. The out‐diffusion of phosphorus from the doped oxide source can be suppressed by placing a non‐doped anodic oxide over it. Reproducibility data for the diffusion results are given. The fabrication of simple device structures and the electrical performance of such devices are described.