铝由于跟硅一起加工的相容性,现在被用作大规模集成电路的金属化材料,铜由于具有低的体电阻率和优良的电迁移阻抗,似乎更好一些。但由于铜易氧化,而且在200℃这样低的温度下即可扩散到硅中并形成铜的硅化物。为了避免大规模集成电路中硅元件的降解,要求在硅和铜之间有一个扩散壁垒。钽是一种重要的壁垒材料,它的熔点高,这样 Aluminum is now used as a metallization material for large scale integrated circuits because of its processability with silicon, which seems to be better due to its low bulk resistivity and excellent electromigration resistance. However, since copper is easily oxidized, it diffuses into silicon at such a low temperature of 200 ° C to form a copper silicide. In order to avoid degradation of silicon components in LSIs, there is a need for a diffusion barrier between silicon and copper. Tantalum is an important barrier material, its melting point is high, so