超薄α-Ta(N)／TaN双层扩散阻挡层的微观结构与热稳定性

Microstructure and thermal stability of an ultrathin α-Ta(N)/TaN bi-layer diffusion barrier

提出利用真空室残余的低浓度N原子制备超薄α-Ta(N)/TaN双层扩散阻挡层的方法,有效地避免了异质元素的引入和高N含量导致的高电阻率。用四点探针(FPP)、X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)进行薄膜电性能和微结构的表征,分析结果表明,利用低浓度氮化工艺,能调控超薄金属Ta膜的相结构,从而获得低阻α-Ta(N)/TaN双层Cu扩散阻挡层结构。高温退火的实验结果证明,此超薄结构具有高的热稳定性,失效温度达600℃。

An uhrathin α-Ta（N）/TaN bi layers diffusion barrier with lower resistance was prepared by a magne- tron sputtering method with using low N concentration. The high resistivity of bi-layer barrier films resulted from the N integration and the introduction of heterogeneous elements for the formation of ultrathin α-Ta were avoided effectively in this deposition method. X-ray diffraction （XRD） and scanning electron microscopy （SEM） were used for characterization of the diffusion barriers microstructure before and after annealing. The results show that the as-deposited a Ta（N）/TaN bi-layer films have low resistivity and good crystallinity,and the α-Ta （N）/TaN bi layer diffusion barrier has an excellent thermally stability. Its failure temperature can be up to 600 ℃.