Crystallization behaviour of amorphous Ge(1 - x)Sbx thin films☆

Abstract The crystallization behaviour of amorphous Ge 1- x Sb x thin films, deposited by sputtering at three compositions: x = 0.68, 0.73 and 0.84 have been studied. The crystallization has been induced by annealing in vacuum and monitored by optical absorption. Samples have been characterized by X-ray diffraction, energy-dispersive X-ray and transmission electron microscopy. The crystallization temperature, Θ c , is composition-depndent and decreases with Sb content. In the crystallization process, three composition intervals can be distinguished. At high Ge content, x ⩽ 0.6, crystallization leads to two separated phases, c-Ge and c-Sb. At x ⋍ 0.68 Sb crystallizes in a first step followed by Ge crystallization. At x ⩾ 0.73, only Sb crystallizes and for the eutectic composition, x = 0.84, Sb crystallizes with [0 0 1] zone axis perpendicular to the film surface as found in pure Sb films.