Kinematic Optimization for Chemical Mechanical Polishing Based On Statistical Analysis of Particle Trajectories

• Published in: IEEE transactions on semiconductor manufacturing Vol. 26; no. 4; pp. 556 - 563
• Main Authors: Zhao, Dewen, Wang, Tongqing, He, Yongyong, Lu, Xinchun
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Chemical mechanical polishing (CMP); Chemical-mechanical polishing; Chemicals; Couplings; Density; Electronics; Exact sciences and technology; Kinematics; Mathematical model; Mathematical models; Mechanical polishing; Microelectronic fabrication (materials and surfaces technology); nonuniformity; particle trajectory; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Slurries; Trajectories; Trajectory; trajectory density; Variability; Statistical method; Microelectronic fabrication; Numerical simulation; Chemical mechanical polishing (CMP); kinematics; nonuniformity; Chemical mechanical polishing; Non uniform distribution; Optimization; Wafer; particle trajectory; trajectory density
• ISSN: 0894-6507; 1558-2345
• DOI: 10.1109/TSM.2013.2281218

The abrasive effect of particles is one of the basic mechanical actions in chemical mechanical polishing (CMP). In this paper, numerical simulations of particle sliding trajectories are performed to examine the influence of the kinematic parameters on the polishing uniformity of typical rotary-type CMP equipment. The trajectory simulations are carried out based on the kinematic analysis. The results reveal that the speed ratio α and the period ratio k T0 , which represent the coupling relationships among the three basic motions of CMP, are the two major factors affecting the trajectory distribution. Further, a trajectory density parameter is proposed to quantitatively evaluate the global uniformity of the trajectory distributions and to optimize the kinematic parameters for better uniformity. The statistical results of the trajectory density analysis reveal that the trajectory of the wafer edge is denser than that of the wafer central area. To obtain better trajectory uniformity, some particular values of α and k T0 , that is, α = 1 and k T0 =1, which imply that the basic motions have a special coupling relationship, should be excluded; the preferred kinematic parameter values for CMP are α = 0.91-0.93 and k T0 =5-7. This paper provides a basic guide to the kinematic parameter settings of CMP.