Investigation On Chemical Mechanical Polishing Performance Of Gallium Arsenide Substrate On Different Crystal Planes

Chemical Mechanical Polishing(CMP)processing technology is an effective way to achieve global planarization of workpiece surface.It can get high accuracy,low surface roughness and no damage surface,so it is widely used in wafer processing.In the actual production,Gallium arsenide wafers with different crystal planes are used as substrates for making different components.However,the surface quality of GaAs wafer with different crystal planes is quite different with the same chemical mechanical polishing process parameters.To this end,the study of chemical mechanical polishing properties of gallium arsenide wafers with different crystal surfaces has a guiding role in the production practice.The main research work in this paper is as follows:The use of variable load scratch experiments were repeated four times scratch test five directions of the three different crystal surface of gallium arsenide wafer in AE automatic scratch tester,automatic scratch tester measured for three wafers in five directions of friction and acoustic emission curve,friction coefficient by least square method to calculate the three chips in five directions,and the average value;then,four repeated scratch test five directions of three kinds of crystal surface of gallium arsenide wafer with constant load scratch test,using the 3D shape measurement of scratch morphology of three kinds of chips,calculated in five directions carved the hardness and the material removal rate,the results show that the friction coefficient,three the wafer in five directions of scratch hardness and material removal rate vary greatly,The values of(100)to(111)15 degree wafers are larger than those of the other two crystal planes.It is shown from these three aspects that the three kinds of gallium arsenide wafers with different crystalline surfaces have serious anisotropy.The differences in chemical and mechanical effects of three kinds of wafers in chemical mechanical polishing were simulated with single silica particles.In this experiment,the wear volume and surface morphology of three wafers under hydrogen peroxide solution and deionized water were studied by changing the loading pressure by single factor experiment.The results show that the wear volume of the three chips in the hydrogen peroxide solution is larger than that in the wear volume of deionized water,but the surface is rough,and under the same pressure(100)to(111)15° wafer the wear volume is the largest;and with the increase of pressure,the wear volume increases,but the surface morphology variation.Finally,the chemical mechanical polishing experiments of three kinds of gallium arsenide wafers with different crystal surfaces were carried out.Four single head polishing machine based on ES36B-4P-4M,the polishing pressure,polishing head speed and effect of the removal rate,surface roughness and TTV polishing speed of three kinds of wafer materials by single factor experiment method,using three-dimensional topography,precision electronic balance,digital micrometer surface morphology,don't measure three kinds of wafer polishing the quality and the thickness of the wafer.The results show that the material removal rate of the three wafers is not satisfied with the linear increase described by the Preston equation,but in a certain range,and the surface roughness of the three wafers is negatively correlated with the material removal rate.According to(100)to(111)15° wafer when the polishing pressure is 90 N,the polishing head speed of 40 r/min and polishing disc speed is 30 r/min,the best the material removal rate and quality for polishing;According to(100)to(111)2° wafer and(100)to(111)60 wafer when the polishing pressure is 90 N,the polishing head speed of 40 r/min and polishing disc speed is 40 r/min,the material removal rate and the polishing quality are the best,and the chip breakage rate is low.