| The research object of this article is6H–SiC，which is mainly used in LED lighting now.In the field of LED, powerful market traction make6H–SiC to replace Si as the thirdgeneration of semiconductor substrate materials. For SiC single crystal itself having highhardness, strong chemical stability and difficult to machining, chemical mechanical polishing(CMP) is currently the only achieveing global level of ultra-precision machining technology,but at present, Lack of understanding of the removal mechanism of CMP limit this processingtechnologyb to be widely used. The development of the polishing liquid is one of the keytechnology of chemical mechanical polishing.The purpose of this study is to develop a kind of SiC abrasive chemical mechanicalpolishing liquid crystal consolidation, and realize the high quality and high efficiency ofCMP, the performance of polishing fluid will directly affect the polishing quality andmaterial removal rate, and is directly related to the surface flat of the SiC crystal. Incombination with the chemical and physical properties of SiC crystal itself, referring to therelevant research methods, reading the related literature, and carrying out the text of thepreparation about polishing liquid, the performance measure after polishing is major ofMRR and surface roughness.This paper is based on the environment of super clean laboratory, its processingequipment is ZYP300grinding polishing machine, it analyses of the chemical properties ofSiC crystal and the effect of polishing liquid ingredient, and selects the elementary element ofthe polishing fluid by single factor experiment: oxidant, PH regulator and surfactant,optimizes the composition and content by the orthogonal experiment. Then this paper willresearch the main technology parameters that the chemical mechanical polishing involves,optimize the composition by the orthogonal experiment, and analyses of the influence law ofprocess parameters by single factor experiment. Finally by developing a high polishingefficiency and good performance of polishing liquid to make it provide the methods and testresults for SiC crystals in ultra-precision machining, provide the technical support andtheoretical basis for further improve the SiC crystal abrasive chemical mechanical polishing liquid projection.By adding different types or content of dispersant, inorganic base, organic alkali, oxidant,surface activity and so on, there are some the corresponding CMP experiment. Through theanalysis of experimental results, it can be get the most Proper composition and content，thecontent of dispersant (NaPO3)6is0.6%, PH regulator is C6H16N2O2contain0.4%,4％contentof oxidant is hydrogen peroxide, the C12H25NaO4S contain0.2%. Reference developed thebasic components of the free abrasive polishing liquid for chemical mechanical polishing ofthe fixed abrasive experiments, We refer to this formula as the basis ingredients ofConsolidation abrasive chemical polishing solution. Through the orthogonal experiment ofconsolidation abrasive chemical mechanical polishing liquid we can get basic components:dispersant sodium (NaPO3)6content0.6%, PH regulator C6H16N2O2content is0.4%, theoxidant (hydrogen peroxide) content is4%.In addition, we conclude the optimum process parameters from the orthogonalexperiment and obtain the influence of various factors on the polishing results through singlefactor experimental. The optimum process parameters: polishing speed for np=nw=60rmp,polishing pressure P=2psi, polishing time for30min, polishing liquid temperature20℃,environment temperature is20℃.The results of research show: The material removal rate of the consolidation abrasivechemical mechanical polishing is higher than the free abrasive chemical mechanical polishingand its abrasive can be Used multiple times, which Reduce the environment pollution. Theconsolidation abrasive chemical mechanical polishing is Promising flat technology. Chemicalreagent of polishing liquid effectively improve the MRR and surface quality. |
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