  A method has been developed to permit the diffusion of Sb into Ge at high
temperatures (~850 C) without contamination by fast diffusing electrically
active impurities in particular by Cu. A liquid metal alloy is used as a getter
of Cu and other fast diffusing impurities. This alloy, Ga- In eutectic,
completely encloses the Ge sample although in physical contact on only one
face. The behaviour of Cu as a contaminant in Ge and the methods known to
prevent and extract (or gather) Cu contamination are reviewed briefly.
Preliminary experiments are described which demonstrate the difficulty of
removing fast diffusing impurities in spite of the use of liquid metal getter
(Ge-In and Au). The advantages and disadvantages of the technique are
discussed.
