化學機械拋光中鑽石修整器設計參數之研究

Study on Parameters of Diamond Dressers in Chemical Mechanical Polishing

蕭啟明(Chi-Ming Hsiao)

指導教授 ： 楊宏智

國立臺灣大學/工學院/機械工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.00304

摘要

化學機械拋光是現在半導體產業中最常被使用的平坦化製程。拋光液中化學溶液的腐蝕與磨粒的機械磨削兩者雙重的作用，使得化學機械拋光能造成晶圓薄膜表面全面平坦化的效果。製程中使用的磨粒與拋光過程中產生的碎屑、副產物，會造成拋光墊表面孔洞產生鈍化的現象，降低繼續輸送拋光液的功能，進而影響晶圓材料的拋光移除率以及表面不均勻度。利用修整器來移除拋光墊表面的鈍化層，將使得拋光墊表面再生露出新的孔洞，繼續運送拋光液的功能。可見修整器設計因數的掌握，以及修整器的加工參數選擇，是化學機械拋光製程是否能充分發揮的關鍵因素。
本研究首先利用單顆鑽石修整器去刮劃拋光墊，觀察並討論鑽石顆粒對材料為高分子聚合物的拋光墊的移除機制與現象為何；同時利用理論推導，建立修整器修整拋光墊的數學模式。接著製作不同鑽石晶形與粒度的陶瓷修整器，並利用拋光研磨機器進行修整模擬。從機台可以控制的參數：修整壓力、拋光墊轉速、修整器轉速、修整時間四者調整，設計不同的修整加工參數，將各顆修整器進行各種條件的修整模擬，得到修整後的修整移除率與表面粗糙度結果，並討論修整器的設計參數與修整參數條件對兩者的影響。最後在修整過後，採取拋光墊的樣本進行掃描式電子顯微鏡拍照，從獲得的照片來觀察拋光墊的表面狀況，對照並討論其與修整移除率、表面粗糙度值與影響輸送拋光液的能力之間的關係。

關鍵字

鑽石修整器 ； 修整加工參數 ； 修整率 ； 表面粗糙度

並列摘要

Chemical mechanical polishing (CMP) is the mostly used planarization process in the semiconductor industry today. Due to the dual actions of chemicals corrosion and abrasive abrasion in the slurry, CMP achieves the effect of global planarization on the thin film surface of wafers. The abrasive, debris and by-product generated in the process cause the pores of the pad surface glazing, which in turn renders the performance of transporting slurry to decrease. Accordingly, the removal rate (RR) and non-uniformity (NU) will be affected. The diamond dressers are used to remove the glazing layer of the pad surface. This action makes the pad restore the ability in transporting the slurry. The dressers’ design factors and the parameters of the dressing process are apparently crucial to the performance of CMP process.
This study was made to observe and discuss the mechanisms of the diamond particles in removing the polymer material. Experimental work was followed by scratching pads with single-diamond dressers, and then a mathematical model was established for dressing rate (DR). The dressing simulation was made to examine DR and the surface condition of the ceramic dressers with different diamond shapes and sizes. The dressing simulation proceeds with different dressing recipes, which consist of four parameters including dressing pressure, pad speed, disk speed, and dressing time. Then the influence of the parameters of dressers and the dressing process on DR and the surface roughness (Ra) was explored. Finally, the scanning electron microscope (SEM) pictures for the surfaces of the sample pads were investigated to explore the relationship among DR, Ra, and the ability in transporting slurry.

並列關鍵字

Diamond Dresser ； Dressing Parameters ； Dressing Rate ； Surface Roughness

參考文獻

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