不含抑制剂的碱性抛光液对铜布线平坦化的研究

本文提出一种碱性铜布线抛光液，其不含通用的腐蚀抑制剂，并对其化学机械抛光和平坦化 (CMP)性能进行了研究。首先研究了此抛光液对铜的静态腐蚀速率和抛光速率，并与含抑制 剂的铜抛光液做了对比实验。在静态条件下，此不含抑制剂的碱性铜抛光液对铜基本无腐蚀速率，而在动态抛光过程中对铜有较高的速率。而含抑制剂的抛光液对静态腐蚀速率略有降低，但是却大幅度降低了铜的去除速率。另外，对铜布线的化学机械平坦化研究表明，此不含抑制剂的碱性铜抛光液能够有效的去除铜布线表面的高低差，有较高的平坦化能力。此抛光液能够应用于铜CMP的第一步抛光，能够去除大量多余铜时初步实现平坦化。

Planarization properties of an alkaline slurry without an inhibitor on copper patterned wafer CMP

The chemical mechanical polishing/planarization (CMP) performance of an inhibitor-free alkaline copper slurry is investigated. The results of the Cu dissolution rate (DR) and the polish rate (PR) show that the alkaline slurry without inhibitors has a relatively high copper removal rate and considerable dissolution rate. Although the slurry with inhibitors has a somewhat low DR, the copper removal rate was significantly reduced due to the addition of inhibitors (Benzotriazole, BTA). The results obtained from pattern wafers show that the alkaline slurry without inhibitors has a better planarization efficacy; it can planarize the uneven patterned surface during the excess copper removal. These results indicate that the proposed inhibitor-free copper slurry has a considerable planarization capability for CMP of Cu pattern wafers, it can be applied in the first step of Cu CMP for copper bulk removal.