奈米鑽石石墨研磨墊應用於化學機械研磨移除晶圓氧化層特性之研究.

Investigation of a Novel Nanodiamond-Impregnated Polishing Pad for Oxide Chemical Mechanical Polishing

化學機械研磨為半導體製程中唯一可達到全面平坦化的關鍵技術。目前應用於化學機械研磨製程中的研磨墊，皆以聚胺酯發泡型高分子為主，因其發泡結構使得研磨墊表面佈滿孔洞可儲存研磨液，但也因孔洞直徑大小不一致，造成研磨液消耗過度。故本研究在聚胺酯高分子中添入兩種比例之奈米鑽石與石墨粉末，成型後製成無孔型奈米鑽石石墨研磨墊並搭配組合式鑽石修整器對晶圓氧化層進行化學機械研磨及機械性質之探討。添入石墨粉末目的在於石墨具備潤濕性質，可使研磨液充分的潤濕研磨墊表面，而添入奈米鑽石粉末目的在於使粉末均勻的分佈於研磨墊上，有助於晶圓氧化層移除。實驗結果顯示：DG103 （1%奈米鑽石3%石墨） 研磨墊之晶圓氧化層移除率比DG000 （聚胺酯）研磨墊來得高，且晶圓氧化層表面的均勻性亦較佳。

This paper presents a chemical mechanical polishing pad by impregnatinga polyurethane matrix with nanodiamond (5-10 nm) and graphiteparticles. Two types of pads-one containing 0.1 wt% nanodiamond with 3wt%graphite and the other comprising 1 wt% nanodiamond with 3 wt%graphite-were manufactured and their respective performances compared.The experimental results confirmed that the nanodiamond-impregnatedpolishing pads showed the smallest contact angle for the slurry, indicatingthat their ability to retain slurry was better than that of a conventionalpolishing pad. Hence, the site to be polished was lubricated better byincreased wetting, leading to faster polishing of the wafer by nanodiamond- impregnated pads without damaging the local circuitry. Oxide CMP testsproved that these nanodiamond-impregnated polishing pads produced abetter wafer removal rate.