Chemical mechanical polishing (CMP) has already become a mainstream technology in global planarization of wafer. The nonuniformity of material removal on wafer surface has a main influence on surface profile of silicon wafer in CMP process. However, the formation mechanism of nonuniformity in wafer CMP has not been fully understood and the influences of CMP process variables on nonuniformity are not fully clear. The nonuniformity of material removal on wafer surface has not been fully understood and the influences of CMP process variables on nonuniformity are not fully clear in CMP process. In this paper, firstly, the equation of particle movement trajectories on wafer surface was built by the movement relationship between the wafer and the polishing pad on a single head CMP machine with line oscillation of carrier. Then the distribution of abrasive trajectories on wafer surface was analyzed at different rotational speed. By the analysis, the relationship between the movement variables of the CMP machine and the With-In-Wafer Nonuniformity (WIWNU) of material removal on wafer surface had been derived. Last, the WIWNU tests were conducted on CP-4 machine. The analysis results are in accord with experimental results. The results will provide some theoretical guide for designing the CMP equipment, selecting the movement variables in CMP and further understanding the material removal mechanism in wafer CMP.

Chemical mechanical polishing (CMP) has become the most widely used planarization technology in the metal and hard-brittle crystal substrate manufacturing process. In this paper, the distinguish method of lubricating behavior in CMP had been analyzed in theory firstly. Then, the tests of CMP with silicon wafer and deposited copper wafer at different polishing pressure had been done. By the test results, the Stribeck curves obtained showed obvious smooth. But in normal CMP conditions, the friction coefficient of polishing area was above 0.1. By analyzing the experimental results, it was concluded that the lubrication state in CMP interface is belong to the boundary lubrication and the material removal is the process of bringing and removed of the chemical reaction boundary lubricating film on hard-brittle crystal substrate surface constantly. The contact form between the workpiece and the polishing pad is the solid-solid contact. These results will provide theoretical guide to further understand the material removal mechanism of in hard-brittle crystal substrate CMP.

In order to understand the material removal mechanism in the process of chemical mechanical polishing (CMP), the states of abrasives in the slurry and on the polishing pad in CMP process have been studied by testing. It was concluded that although the abrasive in the slurry is in the form of agglomeration, but the abrasive on the polishing pad are in approximately uniform layer distribution. The different CMP slurries had been designed for CMP test of MRR. According to analyzing the test results, it was concluded that the mechanical action produced by the abrasive is the main mechanical action in wafer CMP process and the MRR mainly results from the interaction between the mechanical action of the abrasives and the chemical action of slurry. These results will provide a reliable basis for the building of abrasive trajectory model and a theoretical guide to further understanding the material removal mechanism in wafer CMP.

Based on mechanical kinetics theory, the torsional vibration equation of Twist drill is built and solved. Then, according to the characteristics of axial vibration drilling, its torsional vibration performance is analyzed deeply. The result shows that the average torsional deformation of low-frequency axial vibration drilling is less than that of common drilling and the torsional deformation of ultrasonic axial vibration drilling is approach to zero, so vibration drilling has a better surface quality and tool life than common drilling.

According to the law of rigid body around fixed axis rotation, established the mathematical model of motor drive current and instantaneous rotational speed. From the ideal situation of the simulation, according to the same discrete interval of time equal to the same increment of spindle angular velocity conditions, established the discrete closed-loop control system model. In allusion to the disadvantage of calculating corresponding braking current by the instantaneous speed and the instantaneous braking torque measured during the last interval, proposed the control method of calculating braking current by the instantaneous speed and the instantaneous braking torque measured all discrete intervals before current time. Discussed emphatically the computer controlled method based on the discrete closed-loop and phase-locked loop theory which can be used to design the braking current. Evaluated the advantages and disadvantages of the model, and proposed the improved direction.