In situ X‐ray diffraction studies of aluminium‐induced crystallization of hydrogenated amorphous silicon

Thin intrinsic hydrogenated amorphous silicon (α‐Si:H) films (5000 Å thickness) were deposited on (111)‐oriented n ‐type silicon substrates by plasma‐enhanced chemical vapor deposition. A 4000 Å thick Al film was then deposited on the α‐Si:H film by vacuum evaporation. In situ annealing of these films was carried out in an evacuated temperature‐controlled (Model TTK) camera of an X‐ray diffractometer at a glancing angle of 5° using a thin‐film optics attachment. The crystallization behavior of aluminium‐capped α‐Si:H was monitored using the 111 silicon peak as a function of annealing temperature between 273–523 K. The results show that aluminium‐induced crystallization of α‐Si:H initiates at a temperature between 413 and 423 K. The crystallization rate increases with increasing temperature, and saturates for an anneal of 30 min at a temperature of 523 K.