Abstract
Contact stress uniformity is a key issue for the performance of wafer-level chemical–mechanical planarization (CMP) and has been extensively studied during the past two decades. However, contact-stress-related issues are not consistently presented in the literature. In addition, a number of topics remain to be addressed in wafer-level contact analysis. The objective of this article is in twofold. First, it aims to provide a more detailed discussion and stress analysis of the inconsistent issues, including the definition of CMP uniformity, the stress indicator, and the effect of carrier films. Second, contact stress analyses of several important but rarely touched problems are also investigated. Topics to be investigated include: the effects of material hyperelasticity, the effects of a grooved pad, the effects of wafer warpage due to residual stress, and finally the possible advantages of a multizone loading manner. For the first category, this work proposes a new definition of CMP uniformity based on the width of the relatively flat zone. In addition, the contact stress distribution in terms of both von Mises and normal stress are also investigated and their relationship is qualitatively established. Furthermore, the importance of the carrier films is reinvestigated, and the conclusion indicates that their importance is not as significant as previously reported. The hyperelasticity of pad material primarily affects the pad deformation. The presence of pad grooves results in a net increase of contact stress, but the global tendency is unchanged. A warped wafer significantly reduces the contact stress uniformity. By contrast, the multizone loading manner can effectively improve the uniformity of stress distribution. Finally, the stress analyses presented are integrated with a graphic user interface to form a CMP computer-aided design system for further applications. The issues addressed and the conclusions obtained are important for improvement of CMP performance.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Zantye PB, Kumar A, Sikder AK (2004) Chemical mechanical planarization for microelectronics applications. Mater Sci Eng Rep 45:89–220 doi:10.1016/j.mser.2004.06.002
Kim AT, Seok J, Tichy JA, Cale TS (2003) A multiscale elastohydrodynamic contact model for CMP. J Electrochem Soc 150:G570–G576 doi:10.1149/1.1598215
Preston F (1927) Optimization of computer controlled polishing. Glass Tech 11:214–219
Zhou C, Shan L, Hight JR, Ng SH, Danyluk S (2002) Fluid pressure and its effects on chemical mechanical polishing. Wear 253(3–4):430–437 doi:10.1016/S0043-1648(02)00155-2
Maury A, Ouma D, Boning D, Chung J (1997) A modification to Preston’s equation and impact on pattern density effect modeling. Program Abstracts, Advanced Metalization and Interconnect Systems for ULSI Applications
Zhang F, Busnaina A (1998) The role of particle adhesion and surface deformation in chemical mechanical polishing processes. Electrochem Solid-State Lett 1(4):184–187 doi:10.1149/1.1390679
Zhao B, Shi FG (1999) Chemical mechanical polishing in IC processes: new fundamental insights. In: 1999 CMP-MIC conference, Santa Clara, CA, USA, pp 13–22
Runnels SR, Kim I, Schleuter J, Karlsrud C, Desai M (1998) A modeling tool for chemical–mechanical polishing design and evaluation. IEEE Trans Semicond Manuf 11:501–510 doi:10.1109/66.705385
Srinivasa-Murthy C, Wang D, Beaudoin SP, Bibby T, Holland K, Cale T (1997) Stress distribution in chemical–mechanical polishing. Thin Solid Films 308:533–537 doi:10.1016/S0040-6090(97)00433-1
Wang D, Lee J, Holland K, Bibby T, Beaudoin S, Cale T (1997) Von Mises stress in chemical–mechanical polishing processes. J Electrochem Soc 144:1122–1127
Lin YY, Lo SP (2003) A study on the stress and nonuniformity of the wafer surface for the chemical–mechanical polishing process. Int J Adv Manuf Technol 22:401–409 doi:10.1007/s00170-003-1544-y
Lin YY, Lo SP (2004) A study of a finite element model for the chemical mechanical polishing process. Int J Adv Manuf Technol 23:644–650 doi:10.1007/s00170-002-1469-x
Lo SP, Lin YY (2005) The prediction of wafer surface non-uniformity using FEM and ANFIS in the chemical mechanical polishing process. J Mater Process Technol 168:250–257 doi:10.1016/j.jmatprotec.2005.01.010
Chiu JT, Lin YY (2008) Modal analysis of multi-layer structure for chemical mechanical polishing process. Int J Adv Manuf Technol 37:83–91 doi:10.1007/s00170-007-0960-9
Lo SP, Lin YY, Huang JC (2007) Analysis of retaining ring using finite element simulation in chemical mechanical polishing process. Int J Adv Manuf Technol 34:547–555 doi:10.1007/s00170-006-0622-3
Fu G, Chandra A (2005) The relationship between wafer surface pressure and wafer backside loading in chemical mechanical polishing. Thin Solid Films 474:217–221 doi:10.1016/j.tsf.2004.09.010
Tseng WT, Wang YH, Chin JH (1999) Effects of film stress on the chemical mechanical polishing process. J Electrochem Soc 146:4273–4280 doi:10.1149/1.1392627
Shiu SJ, Yu CC (2004) Multivariable control of multizone chemical mechanical polishing. J Vac Sci Technol B 22(4):1679–1687 doi:10.1116/1.1761483
Liao YM, Yan HY, Wang FJ, Chen KS (2006) Mechanical properties characterization for CMP pads. In: 23rd National Conference of the Chinese Society of Mechanical Engineers, Tainan, Taiwan
Hibbit D, Karlsson B, Sorensen P (1998) ABAQUS/standard 5.8 user’s manual. Hibbit, Karlsson, and Sorensen, Pawtucket
Johhnson KL (1985) Contact mechanics. Cambridge University Press, Cambridge
Runnels SR, Renteln P (1993) Modeling the effect of polish pad deformation on wafer surface stress distributions during chemical-mechanical polishing. Dielect Sci Technol 6:110–121
Baker AR (1997) The origin of the edge effects in CMP. Proc Electrochem Soc 96:228–237
Cook RD, Young WC (1999) Advanced mechanics of materials. Prentice-Hall, Upper Saddle River
Ling FF, Lai WM, Lucca DA (2002) Fundamentals of surface mechanics: with applications. Springer, New York
Stoney GG (1909) The tension of thin metallic film deposited by electrolysis. Proc R Soc Lond, A Contain Pap Math Phys Character 82(553):172–175 doi:10.1098/rspa.1909.0021
Hubbard TJ, Antonsson EK (1997) Cellular automata in MEMS design. In Sens Mater Conf, Tokyo, Japan vol. 7, pp 437–448
Wang YC, Yang TS (2007) Effects of pad grooves on chemical mechanical planarization. J Electrochem Soc 154(6):H486–H494 doi:10.1149/1.2716558
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chen, KS., Yeh, HM., Yan, JL. et al. Finite-element analysis on wafer-level CMP contact stress: reinvestigated issues and the effects of selected process parameters. Int J Adv Manuf Technol 42, 1118–1130 (2009). https://doi.org/10.1007/s00170-008-1672-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00170-008-1672-5