Study on Tip-Grit AFM Force Analysis Methods for CMP Process

以AFM顆粒式探針刮削方式分析CMP製程之研究

趙俊傑(Chun-Chieh Chao) ； 陳炤彰(Chao-Chang A. Chen) ； 黃國維(Kuo-Wei Huang) ； 傅尉恩(Wei-En Fu)

《中國機械工程學刊》 37卷5期 (2016/10) Pp. 487-496

摘要

For current integrated circuit (IC) fabrication of semiconductor industry, Chemical Mechanical Planarization/Polishing (CMP) process is one of the major processes that can achieve both global and local planarization of substrates or deposited thin films. However, the interaction force between nano-size abrasive grits and chemical passivized layer by CMP slurry has not yet been clearly observed in current CMP process. This paper is devoted to integrate the nano-scale tip force analysis by Atomic Force Microscopy (AFM) to compare with three common tip-grit (TG) force models and three tip-grit AFM (TGAFM) force analysis methods for calculating the specific tip-grit scratch energy (TGSE). Then the materials removal rate (MRR) based on the TGAFM force on the copper passivation layer of Cu-CMP have also been estimated and discussed. Experimental results show that the MRR of TGAFM in slurry environment is larger than those of Cu-CMP under the equivalent down pressure and the residual of MRR between TGAFM and Cu-CMP is calculated and also verified.

關鍵字

Tip-grit AFM ； CMP ； Cu thin film ； Nano tip force

並列摘要

在半導體生產過程中，化學機械拋光(CMP)是主要製程之一，其目的為將製程中需要平坦化的基材或薄膜，進行全面性與區域性平坦化加工，以利後續製程的順利進行與提高良率。然而，欲直接研究奈米尺寸等級的磨料顆粒、研磨液與鈍化層間的交互作用力，是一件困難的事。本文，針對相關文獻，比較常用的三種顆粒式探針力學模型與三種顆粒式探針AFM 的力分析方法，進而探討銅鈍化層的比刮削能量與銅鈍化層材料移除率。實驗結果顯示，同在研磨液環境中與等效下壓力條件下，AFM 顆粒式探針刮削實驗的材料移除率比化學機械拋光的材料移除率較高且兩者之間材料移除率的差異已被估算與證明。