Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2722
標題: 晶片化學機械平坦化之機械磨耗機制研究與實驗探討
study and experimental investigation of mechanical wear mechanisms for the chemical planarization of silicon wafer
作者: 蔡明義
Tsai, Ming-Yi
關鍵字: CMP;拋光
出版社: 機械工程學系
摘要: 
化學機械平坦化(CMP)技術為進入深次微米半導體元件製程中不可或缺的關鍵技術之一,然而對這種結合化學反應與機械研磨的製程之瞭解依然有限,因此使得CMP相關製程調整與控制的發展倍加艱辛,本研究主要以機械作用的觀點出發,探討在晶片表面-磨漿-拋光墊之間的機械磨耗機制包括磨粒磨耗機制(abrasive-based wear mechanism)與液動磨耗機制(fluid-based wear mechanism),並透過移除率之數學模式分析來討論影響製程之主要參數。另外,由於CMP製程之變數甚多,因此吾人利用田口方法來進行實驗設計,以最少實驗,尋求機械磨耗機制之最佳化加工條件。
實驗結果顯示,移除率會隨著壓力與速度增加而增加,然到一定程度後有下降的趨勢,這種情況與兩個磨耗機制之預測於一定範圍內相符合,而不均勻性會隨著速度增加而快速增加。
另外無背壓補償時,其邊緣的移除率較內緣的移除率嚴重,適度的背壓補償確實有改善不均勻性之效果,此實驗結果與壓力分佈之理論分析相符合。文中亦透過訊號雜音比(S/N ratio)分析及變異數分析,主要影響移除率及不均勻性之因子為壓力、拋光盤速度及磨粒固體含量,而移除率的因子水準越大其值有越佳之趨勢,相反的,不均勻性因子水準越小其值有越佳之趨勢。

Chemical-mechanical planarization or polishing (CMP) is an emerging process used in surface planarization and polishing for silicon wafer with multilevel interconnections. The process combines the chemical reaction between slurry and wafer surface and the mechanical abrasion for material removal. Process model of CMP, however, is not well understood yet as the microscopic chemical and mechanical processes and the interaction between them are still unclear. This paper discusses the wear mechanism of the CMP process form mechanical aspect, including abrasive-based and flow-based wear mechanism and The dominant parameters on the CMP process by these mathematical models. As the CMP process is affected by many parameters, experiments are designed and conducted by the Taguchi method in order to find optimal parameters with minimum experiments.
The material removal rate (RR) and non-uniformity(NU) from experiments show consistency with the two wear mechanism in a certain range. RR increase as polishing pressure and polishing velocity increases while NU becomes worse as polishing velocity increases. It also shows RR at the edge of the wafer is higher than that at the center without back pressure. The NU, therefore, can be improved by suitable back pressure. Experimental result also shows consistency with theoretical analysis of pressure distribution. By the analysis of signal noise to ratio and the analysis of variable, It show that The RR and the NU are dominated by the polishing pressure, polishing velocity and the abrasive content of slurry. The RR increases as these factors increases but the NU becomes worse at the same time.
URI: http://hdl.handle.net/11455/2722
Appears in Collections:機械工程學系所

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