濺鍍法製備Ag-Ge及Ta-Ge之特性

Abstract

Silver and its alloys have bean promising in the multilevel metallization of semiconductor devices because of their superior electrical resistivity and resistance to electromigration. In this study, Ta-Ge and Ag-Ge thin films have been deposited on Si or SiO2/Si substrate by Magnetron sputtering. The as-deposited samples with Ag-Ge/Si and Ta-Ge/SiO2/Si structure were rapidly thermally annealed under Ar+H2 (5%) ambient at various temperatures. In the work, the phase and thermal stability of the thin film alloy ware mainly evaluated by employing XRD, FE-SEM and XPS and the electrical measurements was employed by 4-point probe method. The results showed that pure Ag thin film and a resistivity of 2.1 μΩcm, and that the resistivity of the Ag-Ge films increased with increasing Ge content. The Ag95Ge5 film had the lowest resistivity of 4.5 μΩcm. The XRD patterns for Ag-Ge thin film showed that grain size increased with increasing in annealing temperature, and also increased in adhesion. SEM images of Ag40Ge60 and Ag50Ge50 thin films showed that the porosity of Ag-Ge thin films increased with increasing in Ge content. The TaGe2 and Ta5Ge3 compounds could be formed within a range from 35.94% to 48.86% Ta atomic concentration from XRD results. A sharp decrease in resistance was found when the Ge51Ta49 sample was annealed at 600℃ for 30 min because of the formation of TaGe2.