THERMAL CHARACTERIZATION OF DIELECTRIC AND PHASE CHANGE MATERIALS FOR THE OPTICAL RECORDING APPLICATIONS

摘要

Advances in the phase change optical recording technology strongly depend on the optical and thermal optimizations of the metal/ZnS-SiO_2/phase change multilayer structure, which requires accurate modeling and thermal characterization of PC media structure. In the present work, the thermal conductivities of the amorphous and crystalline Ge_4Sb_1Te_5 (GST) phase change; and ZnS-SiO_2 dielectric layers of thickness in the range of 50 nm to 300 nm have been measured using the transient thermoreflectance technique. The data are between a factor of 2-4 different from the previously measured values for thin film and bulk samples. The thermal boundary resistance at metal/ZnS-SiO_2 interface is found to be around 7 x 10~(-8)m~2W~(-1). This might have serious implications for the future phase change recording application which attempts to achieve the high writing speeds by decreasing the thickness of ZnS-SiO_2 dielectric layer.