Interface roughness during thermal and ion-induced regrowth of amorphous layers on Si(001)

The roughness of Si(001) amorphous/crystalline interfaces, regrown by either solid phase epitaxy (SPE) or ion-beam-induced epitaxial crystallization (IBIEC), has been studied by measuring the scattered x-ray intensity along crystal truncation rods close to Si bulk Bragg peaks. For both regrowth methods, the interface region is well described by a discrete roughness profile. The root-mean-square roughnesses are comparable and rather small: 8.0±0.6 Å and 7.4±0.6 Å for the SPE and the IBIEC regrown sample, respectively. This indicates the presence of a common smoothing mechanism.