BURIED MONOCRYSTALLINE ALUMINUM LAYERS IN BERYLLIUM USING ION-IMPLANTATION

A buried monocrystalline aluminum layer was formed in (101̄0) beryllium by implanting 200 keV Al+ to a dose of 1.1×10 18 Al/cm2 and subsequently annealing the implanted beryllium at 500°C for 1 h. Rutherford backscattering showed layer formation was critically dependent on aluminum dose. Electron microscopy revealed a correlation between this critical dependence and the dose dependence of the density of columnar beryllium defects extending through the aluminum layers from the beryllium overlayer to the beryllium bulk. Several common features found between the formation of this elemental layer and formation of buried compound layers strongly suggest that similar precipitate coarsening behavior is responsible for both.