ULSI Cu互连CoSiN扩散阻挡薄膜的研究

CoSiN薄膜可以作为超大规模集成电路Cu布线互连材料使用。利用磁控溅射技术制备了CoSiN/Cu/CoSiN/SiO2/Si薄膜,利用四探针测试仪、薄膜测厚仪、原子力显微镜、X射线光电子能谱仪等来检测多层膜电阻率、薄膜厚度、表面形貌、元素含量及价态等。考察亚45 nm级工艺条件下CoSiN薄膜对Cu的扩散阻挡性能。实验结果表明,在氩气气氛条件下经500℃,30 min热退火处理后多层膜的电阻率和成分没有发生明显变化,CoSiN薄膜能够保持良好的铜扩散阻挡性能;经600℃,30 min热退火处理后,Cu大量出现在表面,CoSiN薄膜对Cu失去扩散阻挡性能。

Research of CoSiN Film as the Diffusion Barrier Layer in ULSI Cu Interconnection

CoSiN films can be used as Cu wiring interconnection materials in very large scale integrated(VLSI) circuits.The CoSiN/Cu/CoSiN/SiO2/Si films were prepared by magnetron sputtering technology.The resistivity,film thickness,surface morphology,composition and valence state of elements were detected by four-point-probe,film thickness gauge,atomic forced micro-scopy(AFM) and X-ray photoelectron spectroscopy(XPS).The diffusion barrier performance of the CoSiN film for Cu in the sub-45 nm level process condition was investigated.The results show that the resistivity and composition of CoSiN/Cu/CoSiN/SiO2/Si multi-layer films have not the obvious change after thermal annealing at 500 ℃ for 30 min in Ar atmosphere,and the CoSiN film can keep a good diffusion barrier performance for Cu.After thermal annealing at 600 ℃ for 30 min,Cu appeares on the surface abundantly and the CoSiN film loses the diffusion barrier performance for Cu.