Microstructure and recording mechanism of Ge∕Au bilayer media for write-once optical disc

Abstract

The recording mechanism of Ge∕Au bilayer and its dynamic tests for write-once blue laser high density DVD (HD DVD) are investigated. It is found that Ge2Au3 phase is nucleated between amorphous Ge and crystalline Au layer after room temperature deposition. Crystallization of Ge∕Au interface layer at 170–190°C is induced by the nucleated Ge2Au3 sites at the interface, the bilayer structure is further heated to 200–450°C. After heating above 320°C, crystallized Ge are segregated at the grain boundary. The dynamic test results show that this Ge∕Au bilayer films can be applied to 1×–2× HD DVD-R.