Research On The Nanomechanical Properties And Fixed Abrasive Lapping Experiment Of ?-Ga₂O₃

As a new generation of wide bandgap semiconductor materials,single crystal gallium oxide??-Ga₂O₃?has good physical and chemical properties and can be widely used in the field of semiconductor illumination,especially in the application of GaN-based LED substrate materials.The surface roughness of the substrate after ultra-precision processing of the wafer material has nanometer/sub-nanometer precision requirements,but at present,there are still few reports on the Nano-mechanical properties and ultra-precision processing technology of?-Ga₂O₃ single crystal.In this paper,the Nano-mechanical properties of?-Ga₂O₃ and the lapping process of fixed abrasives were studied in depth,which has positive guiding significance for the practical application of?-Ga₂O₃ materials.The main research contents and conclusions are as follows:The Nano-mechanical properties such as hardness and elastic modulus,as well as mechanical behaviors such as elastic deformation and plastic deformation of?-Ga₂O₃?100?and?010?crystal planes were studied by Nanoindentation and Nanoscratch test methods.Through the analysis of the results of the Nanoindentation test,it was found that the pop-in phenomenon appears in the load-displacement curves of both sides,and the indentation load of the?100?and?010?faces when pop-in occurs for the first time were:4.31mN and5.42mN,respectively.The first occurrence of pop-in in the process of Nanoindentation is the critical point of crystal material transition from elastic deformation to plastic deformation,and the corresponding internal shear stress values are 60.02GPa and60.84GPa,respectively.The normal stress values are 14.39GPa and 14.17GPa,respectively.It was found that the hardness of the?100?plane is 10.7GPa,which is lower than the hardness of?010?of 12.3GPa.With the increase of the maximum indentation load, the hardness of both crystal faces is significantly reduced and tends to be stable,showing obvious"size effect".The elastic moduli of the?100?face and the?010?face were209.6GPa and 197.7GPa,respectively.The results show that the cutting depth range of the plastic domain of the?100?and?010?planes of the?-Ga₂O₃ is 96 nm⁵76 nm and 84nm⁴21 nm,respectively.Through the fixed abrasive lapping experiment,the effects of abrasive particle size and lapping pressure on the material removal rate and surface roughness of?-Ga₂O₃ wafer lapping were investigated,and the different materials removal characteristics of?-Ga₂O₃?100?and?010?planes were analyzed.Experimental results showed that the removal rate of?-Ga₂O₃ material increases with the increase of pressure and particle size,but when the abrasive particle size is larger than W28,the influence of particle size on the change of material removal rate is not obvious.The surface roughness increases as the abrasive grain size increases,the increased lapping pressure has little effect on the surface roughness.The?-Ga₂O₃?100?surface is an easy-clear surface,under this experimental conditions,the material removal method of the?100?surface was mainly based on cleavage and peeling,and that of the?010?surface was mainly based on brittle fracture,the?100?surface material is easier to remove than the?010?surface,but the roughness after processing is not as good as the?010?surface.Through optimization experiments,with a diamond fixed abrasive grinding process using a 3%5?m particle size silicon carbide micropowder slurry,a W28 diamond abrasive grain and a grinding pressure of 110g/cm²,?-Ga₂O₃?100?and?010?planes can be processed at removal rates of 17.75?m/min and 17.28?m/min,respectively,and the surface roughness after processing is 214.12 nm and 119.88 nm,respectively.The?-Ga₂O₃ material can be efficiently removed during the rough lapping.Figure[44]table[6]reference[66]...