4.结论本文中，运用分子动力学方法模拟来研究划擦过程中砷化镓材料表面划

4. Conclusion In <br>this paper, the molecular dynamics simulation is used to study the formation of scratches on the surface of gallium arsenide materials during the scratching process, and to understand the formation process of gallium arsenide scratches under different factors. The depth of scratches, the width of scratches, the amount of scratches raised, the width-to-depth ratio of scratches and the average friction coefficient were used as evaluation indicators to explore the processing parameters to reduce the formation of scratches. <br>1. For the (100) crystal face of GaAs, the simulation analysis of the scratch characteristics during the scratching process under different abrasive particle sizes is carried out. The larger the abrasive particle size, the greater the depth, width and normal of the abrasive particles. The force gradually increases, and the average coefficient of friction during the scratching process gradually decreases. As the particle size of the abrasive grains increases, the amount of ridge uplift increases first and then decreases. Increasing the particle size of the abrasive particles will increase the contact area between the abrasive particles and the surface of the material, and the time to polish the workpiece will decrease accordingly. Therefore, the selection of the particle size of the abrasive particles should be based on the actual polishing processing requirements to make it able to Meet the performance requirements of polishing, and can improve efficiency. <br>2. During the scratching process, the scratching speed has little effect on the formation of scratches on the GaAs surface. <br>3. In the process of processing, it is necessary to appropriately select the GaAs crystal plane and the processing direction of the abrasive grains. On the premise of satisfying the requirements for use, choose two scratch directions close to the (111) crystal plane and 45° and 135°. The crystal plane and crystal phase will affect the shape of the scratch and the location of the atomic stack. For GaAs (100) deviated from (111) 15° crystal planes than (100) deviated from (111) 2°, (100) deviated from (111) 6° these two crystal planes of gallium arsenide scratch width and uplift It is smaller, but the scratch depth of the 15° crystal plane is deeper than that of the other two crystal planes, causing more damage. In the simulation process of the same type of gallium arsenide crystal, the scratch depth, width and bulge in the directions of 45° and 135° are smaller than those in the directions of 0°, 90° and 180°; during the simulation of scratches, The average friction coefficient during the scratching process under different crystal planes is also different. When the scratch direction is 45°, the average friction coefficient is the largest, and the friction coefficients in the three directions of 0°, 90°, and 180° are not different.

4.Conclusions<br>In this paper, molecular dynamics simulation is used to study the formation of surface scratches of gallium arsenide materials during scratch, and to understand the formation of gallium arsenide scratches under different factors. The processing process parameters to reduce the formation of scratches were explored by using scratch depth, scratch width, scratch uplift, scratch depth ratio and average friction coefficient as evaluation indicators.<br>1. For GaAs's (100) crystal surface, the simulation and analysis of the scratch features in the stroke of different grinding particle sizes, the larger the particle size, the depth, width and the normal force of the scratches gradually increased, and the average coefficient of friction in the scratch process is gradually decreased. As the particle size increases, the uplift of the scratch is increased first and then decreased. The increase in the size of the grinding particles will increase the contact area between the grinding grain and the surface of the material, and the time of the polishing workpiece will be reduced, so the choice of the particle size should be based on the actual polishing processing requirements, so that it can meet the performance requirements of polishing, but also improve efficiency.<br>2. During the scratch process, the scratch speed has less effect on the formation of scratches on the surface of GaAs.<br>3. In the process of processing, to choose the proper processing direction of GaAs' crystal surface and grinding grains. In the premise of meeting the requirements of use, choose close to (111) crystal surface and 45 degrees, 135 degrees two scratch direction. The crystal face and the crystal phase affect the shape of the scratches and the position of the atomic build-up. For GaAs (100) partial (111) 15 degrees of the crystal face ratio (110) partial (111) 2 degrees, (100) partial (111) 6 degrees of the two crystal surface arsenic scratch width and uplift is smaller, but the 15 degrees crystal surface depth is deeper than the other two crystal surface slots deeper, resulting in greater damage. During the simulation of the same arsenide crystal surface scratch, the depth, width and uplift of the scratch in the direction of 45 degrees, 135 degrees were smaller than the three directions of 0, 90, 180 degrees, and the average friction coefficient in the process of different crystal surface scratches was also different, and the average friction coefficient was not significant in the three directions of 0, 90 degrees.

4. Conclusion<br>In this paper, molecular dynamics simulation is used to study the scratch formation of GaAs surface in the scratch process, and to understand the scratch formation process of GaAs under different factors. Based on the evaluation indexes of scratch depth, scratch width, scratch protrusion, scratch width depth ratio and average friction coefficient, the processing parameters of reducing scratch formation are explored.<br>1. For the (100) crystal surface of GaAs, the simulation analysis of scratch characteristics in the process of scratching with different particle sizes is carried out. The larger the particle size is, the deeper, wider the scratch and the normal force on the abrasive gradually increase, and the average friction coefficient in the process of scratching gradually decreases. With the increase of abrasive particle size, the amount of scratch bulge increases first and then decreases. With the increase of abrasive particle size, the contact area between abrasive particles and material surface will increase, and the time for polishing workpiece will decrease accordingly. Therefore, the selection of abrasive particle size should be based on the actual polishing processing requirements, so that it can meet the polishing performance requirements and improve efficiency.<br>2. In the process of scratch, the scratch speed has little effect on the formation of scratches on GaAs surface.<br>3. In the process of processing, the processing direction of GaAs crystal surface and abrasive should be properly selected. On the premise of meeting the use requirements, two scratch directions close to (111) crystal surface and 45 ° and 135 ° are selected. The shape of the scratch and the position of atom accumulation are affected by the crystal surface and crystal phase. For GaAs (100) biased (111) 15 ° faces, the scratch width and protrusion of GaAs (100) biased (111) 2 ° faces and (100) biased (111) 6 ° faces are smaller, but the scratch depth of 15 ° faces is deeper than that of the other two faces, resulting in greater damage. In the scratch simulation of the same GaAs crystal surface, the scratch depth, width and bulge in 45 ° and 135 ° directions are smaller than those in 0 °, 90 ° and 180 ° directions; in the scratch simulation process, the average friction coefficient in the scratch process under different crystal surfaces is also different. When the scratch direction is 45 °, the average friction coefficient is the largest, and the friction coefficient in 0 °, 90 ° and 180 ° directions is not much different.<br>