碱性抛光液在CMP过程中对低k介质的影响

Effects of Alkaline Slurry on Low-k Dielectrics in CMP Process

以p型<111>硅片为衬底,经过旋涂固化制备低介电常数(低k)材料聚酰亚胺。经过化学机械抛光(CMP)过程,考察实验前后低k材料介电性能的变化。实验中分别使用阻挡层抛光液、Cu抛光液以及新型抛光液对低k材料进行抛光后,利用电参数仪对低k材料进行电性能测试。结果显示,低k材料介电常数经pH值为7.09新型抛光液抛光后,k值由2.8变为2.895,漏电流在3.35 pA以下,去除速率为59 nm/min。经新型抛光液抛光后的低k材料,在电学性能等方面均优于阻挡层抛光液和Cu抛光液,抛光后的低k材料的性能能够满足应用要求。

The low-k material Polyimide （PI） was made on the p 〈 111 〉 silicon substrate by spincoating and solidifying, which was fabricated by using chemical mechanical polishing （CMP）. After CMP process, the electrical properties of the low-k material were observed before and after experiments. In this experiment, the low-k material was polished by the barrier slurry, the Cu slurry and the new slurry, and the changes of the electrical properties of the low-k material were tested. Several types of slurries were utilized to evaluate their effects on the properties of low-k films. The results show that for the low-k material polished by the new slurry of pH 7.09, the dielectric constant changes from 2. 8 to 2. 895, the leakage current is lower than 3.35 pA and the remove rate is 59 nm/min. The low-k material polished by the new slurry is superior to the barrier slurry and Cu slurry on the electrical properties. The performance of low-k materials can be potentially applied in the manufacture after polishing.