摘要
采用直流磁控溅射方法在p型(100)Si衬底上制备了Cu/Ta、Cu/Ta-N和Cu/Ta-Al-N复合膜,并对薄膜样品进行了卤钨灯快速热退火。用四探针电阻测试仪(FPP)、AFM、SEM、Alpha-step IQ台阶仪和XRD等分析测试方法对样品的形貌结构与特性进行了分析表征,并对N和Al的掺杂机理进行了讨论。实验结果表明,Ta、Ta-N和Ta-Al-N膜层的Cu扩散阻挡特性逐渐增强,Ta/Si界面上的反应和Cu通过多晶Ta膜扩散到Si底并形成Cu_3Si共同导致了Ta阻挡层的失效,而Cu通过Ta-N和Ta-Al-N结晶后产生的晶界扩散到Si底并形成Cu_3Si是两者失效的唯一机制。N的掺入促进了非晶薄膜的形成且有利于消除界面反应,而Al的掺入将进一步提高薄膜的结晶温度和热稳定性。
Cu/Ta, Cu/Ta-N and Cu/Ta-AI-N multilayer structures were deposited on p-type Si（100） substrates by DC magnetron sputtering, then rapid thermally annealed by tungsten halide lamp. The surface morphology and properties of the thin-films were investigated by four-point probe（FPP） sheet resistance measurement, AFM, SEM, Alpha-step IQ profilers and XRD, also the effects of N and Al doping on diffusion barrier property were discussed. The experimental results show that the barrier properties against Cu diffusion are gradually enhanced from Ta, Ta-N to Ta-AI-N. The interface reaction of Ta/Si together with CusSi, which resulted from Cu diffusion along the grain boundaries towards Si, make Ta barrier failed, while the failure of Ta-N and Ta-AI- N are both only attributed to the formation of Cu3Si on barrier/Si interface which is due to Cu diffusion along the grain boundaries of crystallized barrier films. N doping favors the formation of amorphous thin-film and eliminates the interface reaction, while Al doping increases crystallization temperature and enhances thermochemical stability of thin-film.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第4期655-658,共4页
Journal of Functional Materials
基金
国家自然科学基金(60371046)
关键词
直流磁控溅射
Ta基纳米薄膜
Cu扩散阻挡层
阻挡特性
DC magnetron sputtering
Ta-based nanoscale thin-film
Cu diffusion barrier
diffusion barrier property
