Identification of EOR defects due to the regrowth of amorphous layers created by ion bombardment

In this paper TEM investigations have been carried out on typical EOR defects found in Ge-amorphized (001) wafers (Ge → Si, 150 keV, 2×1015 ions/cm2) after thermal annealing (RTA, 1000°C, 10 s). These defects consist of medium sized (10–50 nm) dislocation loops that have been characterized by conventional electron microscopic techniques. Most of them (~ 75%) are circular faulted Frank loops with b = a3〈111〉 vectors. The remaining (~ 25%) loops are perfect elongated hexagon-shaped loops: they have nearly t(111⊃ habit planes, with b = a2〈101〉 vectors. Hence, it is possible to deduce from only one TEM image the number of Si atoms available in the loops as well as the density of the loops for different implantation or annealing conditions. This is needed for optimization of process conditions.