The Technology Research Of Magnetic Composite Abrasive Chemical Mechanical Polishing Assisted By Pulse Magnetic Field

Magnetic Composite Abrasive Chemical Mechanical Polishing(MCA-CMP)is a new chemical mechanical polishing method with a high material removal rate,in which the magnetic polymer microspheres/SiO2 composite abrasives are anchored on a glass tool plate by the magnetic force,and the dependence between diameter of composite abrasive and morphology of tool plate is reduced.The further improvement of material removal were restricted by abrasives aggregation that formed in constant magnetic field,which was revealed in existing research.The paper presents new polishing method that used pulse magnetic field as assistant magnetic field.The distribution of magnetic polymer particles in magnetic-flow coupling field was also analyzed.The main task and conclusion are as follows:1.According to the basic principles of polishing,a magnetic field pulse assisted chemical mechanical polishing experimental platform was set up through the transformation of the existing polishing machine.2.A pulse magnetic field generating device was designed based on the process needs and theoretical calculation,and the distribution of magnetic field of the device was simulated by ANSYS.3.Because of the magnetic force,magnetic polymer particles were deposited and anchored on the tool plate.Magnetic field density was an effective factor for deposit of magnetic polymer particles,its continuing role would result in magnetic abrasives aggregation.Magnetic polymer particles were deposited and entered in to polishing area easily without magnetic abrasives aggregation,owing to the pulse magnetic field with a certain frequency.4.Experiments of polishing silicon wafer,using a pulse magnetic field with a certain frequency and duty cycle,the material removal rate was significantly improved,which is related to the coordination degree between the role and intermittent.