Abstract
Electrical resistivities of PdCuSi thin film metallic glasses (TFMGs) are investigated as a function of annealing conditions in an attempt to control crystallization of the PdCuSi TFMG in order to reduce electrical resistivity without inducing embrittlement. Glass transition temperature T_g, crystallization temperature T x and electrical resistivity of the as-sputtered Pd_<76>Cu_6Si_<18> TFMG are 638K, 663K and 64μΩcm. Resistivity of Pd _<76>Cu_6Si_<18> TFMG is found to decrease as crystallization proceeds. Although the resistivity of Pd_<76>Cu_6Si_<18> TFMG annealed at 633K (= T_g - 5K) for 60s does not decrease, because the material remains amorphous, the resistivity of Pd_<76>Cu_6Si_<18> TFMG annealed at 633K for 600 s does decrease by a few K, even though the specimen is still amorphous. Stress relaxation of Pd_<76>Cu_6Si_<18> TFMG is thus thought to occur by glass transitions. When annealed at 633 K for over 1200s, Pd_<76>Cu_6Si_<18> TFMG becomes partially crystallized, and electrical resisitivity decreases with increasing annealing time. Pd_<76>Cu_6Si_<18> TFMG annealed at 633K for 2700s becomes completely crystallized, giving an electrical resisitivity of about 30μΩcm. Annealing Pd_<76>Cu_6Si_<18> TFMG at 643K (= T_g + 5K) for 600s also results in complete crystallization. During crystallization of Pd_<76>Cu_6Si_<18> TFMG, γ-(Pd-Cu) and Pd solid solution crystallize first out of the amorphous phase. At this point, Pd_<76>Cu_6Si_<18> TFMG exhibits a sufficiently high strength, with electrical resistance reduced to about 50μΩcm. After further annealing, Pd-silicides, Pd_4Si and Pd_3Si, are formed and Pd_<76>Cu_6Si_<18> TFMG is crystallized completely. Although this gives an electrical resistivity of about 30μΩcm, the specimens become very brittle.
