Interaction between Arsenic and Aluminum in Germanium

The behavior of As in Ge containing regions doped with ∼5×10^20∕cc Al was studied. The solubility of As is enhanced tenfold or more by the heavy Al doping, on the basis of (1) measurements of conductivity type and (2) the negative results of a search for compounds by x‐ray diffraction. The behavior of As diffusion fronts was studied by observing the progress of the p‐n junction formed in Ge containing 10^(17)∕cc In. When a region of heavy Al doping was added, the p‐n junction was displaced. The displacements indicate that the diffusing As is attracted to regions of heavy Al doping. These results are similar to those of Reiss, Fuller, and others for Li in Si, though a detailed understanding is not yet available in the present case