Effects of Chemical Mechanical Polishing Parameters on Acoustic Emission Characteristics
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摘要: 化学机械抛光(CMP)是实现晶圆全局平坦化的主要手段,分析CMP过程的声发射特征对探究CMP机理、监测CMP过程具有重大意义。以半导体互连材料铜为对象,分析铜CMP过程的声发射特征,探索CMP过程产生声发射(AE)信号的机制。研究发现:随着抛光压力和抛光垫转速的增加,AE信号强度增大;CMP过程通入的液体成分对AE信号有较明显的影响;AE信号的能量主要分布在两个频段,其中高频成分能够表征CMP过程的划痕。Abstract: Chemical mechanical polishing (CMP) is a dominating way to realize global planarization of wafers, and acoustic emission is very sensitive to material damage. So it is of great significance to investigate acoustic emission characteristics during CMP for CMP mechanism research and process monitoring. Here acoustic emission characteristics and signal generating mechanism during CMP were studied using copper, a kind of interconnection material of semiconductors. The results demonstrate that the intensity of acoustic emission signal increases with the increase of polishing pressure and pad rotational speed. The signal is obviously influenced by the ingredient of liquid pumped in as well. Besides, signal energy distributes mainly within two frequency bands, and the higher frequency component is able to characterize scratches during CMP.
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Keywords:
- chemical mechanical polishing /
- acoustic emission /
- copper /
- scratch
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[1] CHUNG J B, ASIBU E K. Acoustic emission from plastic deformation of a pure single crystal[J]. Journal of Applied Physics, 1992, 72(5):1812-1820.
[2] MASLOV L I, GRADOV O M. Fracture energy analysis via acoustic emission[J]. International Journal of Fatigue, 1986, 8(2):67-71.
[3] DORNFELD D A, LEE Y, CHANG A. Monitoring of ultraprecision machining processes[J]. The International Journal of Advanced Manufacturing Technology, 2003, 21(8):571-578.
[4] MARINESCU I, AXINTE D. A time-frequency acoustic emission-based monitoring technique to identify workpiece surface malfunctions in milling with multiple teeth cutting simultaneously[J]. International Journal of Machine Tools and Manufacture, 2009, 49(1):53-65.
[5] BLUM T, INASAKI I. A study on acoustic emission from the orthogonal cutting process[J]. Journal of Engineering for Industry, 1990, 112(3):203-211.
[6] TANG J, DORNFELD D, PANGRLE S K, et al. In-process detection of microscratching during CMP using acoustic emission sensing technology[J]. Journal of Electronic Materials,1998,27(10):1099-1103.
[7] LEE D E, HWANG I, VALENTE C M O, et al. Precision manufacturing process monitoring with acoustic emission[J]. International Journal of Machine Tools and Manufacture,2006,46(2):176-188.
[8] KAUFMAN F B, THOMPSON D B, BROADIE R E, et al. Chemical-mechanical polishing for fabricating patterned W metal features as chip interconnects[J]. Journal of the Electrochemical Society, 1991, 138(11):3460-3465.
[9] LUO J, DORNFELD D A. Material removal mechanism in chemical mechanical polishing:theory and modeling[J]. IEEE Transactions on Semiconductor Manufacturing,2001,14(2):112-133.
[10] GUO L, SUBRAMANIAN R S. Mechanical removal in CMP of copper using alumina abrasives[J]. Journal of the Electrochemical Society, 2004, 151(2):104-108.
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