Solid-state amorphization of gold and silicon bilayer films by annealing

ABSTRACT

Interfacial reactions in vacuum-deposited gold and silicon bilayer films were investigated by transmission electron microscopy and electron diffraction. By heating to 453 K, an amorphous Au–Si structure formed in gold films deposited at room temperature on both crystalline and amorphous silicon films, and the amorphization strongly depended on the grain size of the gold films. The driving force for the formation of the amorphous Au–Si structure was analyzed based on the free energy increase due to defects, such as grain boundaries, in the gold films on silicon films. The amorphization was concluded to be a transformation from the crystalline phase to the undercooled liquid Au–Si phase.

KEYWORDS:

• Au-Si bilayer films
• amorphization
• solid state reaction
• metastable phase

Disclosure statement

No potential conflict of interest was reported by the author(s).