Anomalous Behavior of Copper during Acceptor Diffusions into Gallium Arsenide

Abstract

A radioactive tracer study of the behavior of copper during acceptor diffusions into gallium arsenide has clearly shown anomalous copper concentration profiles. A pronounced minimum in the copper diffusion profile was found in the vicinity of the electrical p‐n junction. The shape and position of this minimum was dependent only on those diffusion conditions (time and temperature) which affected the indiffusing acceptor. Crystal origin, crystal orientation, and annealing had no effect on the copper diffusion profile. It is felt that the minimum or dip in the profile is caused by the large built‐in field of the p‐n junction which sweeps out the singly charged copper interstitials in the vicinity of the junction.