Research On Process Parameters Optimization Of Monocrystalline Silicon Double-sided Grinding Machine

As a representative of silicon materials,monocrystalline silicon is widely used in the field of semiconductor devices.Grinding is a key process in monocrystalline silicon processing and it’s the only way which must be passed for technological breakthroughs in the field of silicon wafer manufacturing.In order to improve the production efficiency of the monocrystalline silicon double-sided grinding machine,which is independently developed by the enterprise,and improve the quality of the finished silicon wafers,this research optimized the main process parameters of the grinding process.The specific research content includes:(1)According to the double-sided grinding material’s removal mechanism,a monocrystalline silicon material removal model is constructed;according to the movement characteristics of the double-sided grinding process,a motion model is constructed.(2)Use MATLAB software to simulate the model.Through the analysis of the material removal model’s simulation results,it is concluded that the process parameters such as the concentration of the grinding fluid,the processing pressure and the grinding speed have an important influ ence on the removal of the grinding material;through the trajectory analysis of the motion model,it is concluded that the double-sided grinding movement are mainly affected by the initial position of the silicon wafer and the rotation speed of the grinding disk.The construction of the two models and the simulation research provide theoretical basis and direction guidance for subsequent single factor experiments.(3)Design single factor experiments.Propose the silicon wafer detection indicators that are required for the experiment.Design single-factor experiments for the three main process parameters of grinding speed,grinding pressure,and grinding liquid concentration,then record and analyze the experimental data.The correctness of the theoretical model is verified by discussing the relationship between the test results and the values of each process parameter.Through single factor analysis,the ideal values of the three parameters are initially obtained.(4)Design orthogonal experiments.Consider the three process parameters comprehensively.Use the ideal range of the process parameters obtained from the single factor experiment to design an orthogonal experiment.Determine the final process parameters,the grinding liquid concentration is 28%;the grinding speed is 32r/min;the processing pressure is 4kpa.Subsequently,compare the quality of the output silicon wafers before and after the process improvement.The detection indicators Warp value,TTV value,and Ra value were slightly reduced,and the drop was 25-30%.The Bow value improvement effect was obvious,which was reduced by more than 40%,and the wafer surface accuracy and surface roughness are optimized;processing efficiency is improved significantly.Verify the effectiveness of the new process parameters plan.