集成电路Cu金属化中的扩散阻挡层

Diffusion Barrier of Cu Metallization in ULSI

阐述了集成电路Cu互连中的技术难题,重点讨论了Cu的扩散问题,综述了扩散阻挡层的研究发展进程,重点介绍了当今研究较多的难熔金属、难熔金属氮化物及其三元结构阻挡层的最新进展情况。研究表明,阻挡层的阻挡性能与制备工艺、薄膜组分及微观结构密切相关,其失效机制多为高温下阻挡层晶化所产生的晶界为Cu扩散提供了快速通道,掺入Si或其它原子的难熔金属氮化物由于其较高的晶化温度和良好的阻挡性能正成为研究热点。

The paper reviews the urgent problems about Cu metallization in ULSI, especially introduces the problem of Cu diffusion. The paper summarizes the research development situation of diffusion barrier, and mainly introduces the newly research development of refractory metals and their ternary structure diffusion barriers. The research indicates that the diffusion barrier properties are sensitively associated to the preparation techniques, film composition and microstructures. The failure mechanism is mainly due to the grain boundaries formed after annealing which can act as fast diffusion paths for Cu. Addition of silicon and other atoms to the nitride refractory metals is widely studied because it can increase the crystal temperature and improve the diffusion barrier properties.