不同磨料质量分数对化学机械平坦化的影响

Effects of Different Abrasive Mass Fractions on the Chemical Mechanical Planarization

采用自主研发的碱性铜抛光液,在E460E机台上研究了不同磨料质量分数对铜和钽抛光速率与膜厚一致性的影响;分析了磨料质量分数为2%,2.8%和3.6%时,膜厚一致性对平坦化的影响。抛光结果显示:当磨料质量分数高于2.8%时,抛光液开始对钽进行有效的抛光;随着磨料浓度的增加,抛光液的膜厚一致性提高趋于平缓。磨料质量分数为2.8%和3.6%时,抛光后膜厚一致性变好,碟形坑满足工业生产要求;磨料质量分数为2%时,抛光后膜厚一致性比抛光前恶化,碟形坑相对较大。由此可见,当磨料质量分数为2.8%时,抛光液能有效去除残余铜,并且抛光后膜厚一致性好,有利于实现平坦化,尤其是对提高成品率和优品率有重要的作用。

The effects of different abrasive mass fractions on the removal rates of Cu and Ta and the uniformity of the film thickness were investigated with the self-made copper slurry on the E460E platform. Besides that, the effect of the uniformity of the film thickness on the chemical mechanical planarization was analyzed with the abrasive mass fractions of 2 %, 2.8 % and 3.6 %. The polishing results show that when the abrasive mass fraction is above 2.8 %, the slurry begins to polish Ta effectively. With the increase of the abrasive mass fraction, the uniformity of the film thickness increases slightly. When the abrasive mass fractions are 2.8 % and 3.6 %, the uniformity of the film thickness becomes good after polishing, and the values of the dishing can meet the industrial requirements. However, when the abrasive mass fraction is 2%, the uniformity of the film thickness tends bad after polishing, and the value of the dishing increases significantly. Thus, when the abrasive mass fraction is 2.8G, the slurry can remove the residual copper efficiently and the uniformity of the film thickness becomes good after polishing, which is conducive to achieving the planarization, especially to the enhancement of the yield and optimal product rate.