Design And Manufacturing Of Bionic Polishing Pad And Research On Kinematical Analysis Base On Sunflower Seed Pattern

Chemical mechanical polishing (CMP) as a critical technology in integrated circuit (IC) manufacturing is widely used to achieve a high degree of the local or global planarization of the substrate silicon wafer. And the minimum resolvable feature size decreases and the silicon wafer siza increases in IC manufacturing. In order to ensure the degree of local or global planarization of silicon surface, researchers in various fields focus on the polishing pad and the movement of chemical mechanical polishing (CMP) and the material removal volume distribution (MRVD). But to solve this problem, it is very important to research the morphology of the pad and the movement mechanism, and it also very meanful to high-quality and high-precision silicon surface.This paper presents a new kind of polishing pad has been designed based on the phyllotaxis theory of biology. After analysis the problems of movement mechanism, focus on the trajectory and the material removal volume distribution (MRVD) of bionic polishing pad.Firstly, from the theory of single grinding trajectory, base on swing polishing machine, analysis the trajectory of different phyllotaxis parameter pad, and compared with ordinary polishing pad, concluded that when the revolution speed of the polishing platen n0=50 r/min and the central angle of arm a=15°and the swing speed of the swing shankθm=25°, the trajectory of bionic pad is ideal, and received higher degree of silicon surface.Secondly, the kinematical equation and the distribution model of material removal rate (MRR) have been established on the base of the cutting theory of single abrasive gain. With the help of those equation and model, the material removal volume distribution (MRVD) is calculated and analyzed. he effects of the movement parameters of polisher and the phyllotais parameters of polishing pad on the cutting trajectory and the MRVD are obtained. The results show that the uniformity of the dimensionless distribution of the material removal volume (DDMRV) on wafer surfaces can be improved when the revolution speed of the polishing platen is between 20 r/min and 30 r/min or large than 20 r/min, its center angle may large than 15°or equal to it, the swing speed of the swing shank may between 20°and 25°, the phyllotaxis parameters between 2.0 and 2.4. And the experimental results and theoretical simulation results are basically consistent.