Precipitation of Copper in Germanium

The density of dislocations is shown to have a marked effect on the rate of anneal of copper in germanium. At 500°C samples containing high dislocation density (∼${10}^6$/${\mathrm{cm}}^2$) anneal in about 1 hour in contrast to material of low dislocation density (∼${10}^4$/${\mathrm{cm}}^2$) which requires about 24 hours. When copper-doped germanium is cooled from a high temperature in regions of high dislocation density, significant precipitation occurs in a cooling cycle of only a few seconds. In this case, in order to prevent precipitation the sample must be quenched from the high temperature in a time of the order of 0.1 second.