Simulation Of SiC Induced Crystallization Behavior At Different Temperatures

Silicon carbide(SiC)is the third generation of semiconductor materials,with a wide band gap,high thermal conductivity,high breakdown electric field,high electron saturation drift speed,strong radiation resistance and other excellent performance,showing great advantages,the industry has entered the stage of rapid development.In this paper,the induced crystallization behavior of silicon carbide at different temperatures was simulated by molecular dynamics simulation.Firstly,the influence of temperature on the solid-liquid interface model of silicon carbide was investigated.Secondly,the crystallization effects of the solid-liquid model of silicon carbide on different crystal surfaces were compared.Finally,the microstructure changes at the solid-liquid interface were analyzed.(1)Different temperatures have different effects on the solid-liquid model of silicon carbide.Through exploration,the optimal growth temperature of silicon carbide can be found.At this temperature,the crystallization rate is the highest and the crystal quality is the best.We can also find the stationary temperature point of the solid-liquid coexistence,which is the thermodynamic melting point.Above the thermodynamic melting point,the solid-liquid model will melt completely,the higher the temperature,the faster the melting.(2)During the relaxation growth process of(100)crystal plane model,(110)crystal plane model and(111)crystal plane model in the simulation process,the solid atoms will induce the liquid atoms to crystallize continuously under the appropriate temperature.The fastest growth rate is(100)crystal surface.The optimal growth temperature of the three models is different:(100)the maximum optimal growth temperature of the crystal surface is 3500 K,while(110)the minimum optimal growth temperature of the crystal surface model is 3100 K,and(111)the optimal growth temperature of the crystal surface model is 3250 K between the two models.(3)The crystal structure of(100)crystal plane and(110)crystal plane is sphalerite no matter at what temperature.In the crystal surface model of(111),there are two structures: sphalerite and wurtzite.At the temperature of 3250 K,the more sphalerite structures there are,the temperature conducive to wurtzite structure is 3000 K.(4)In the induced crystallization process,the crystal surface(100)is the most obvious interface shift,followed by(110)crystal surface,from the initial smooth interface with time to concave and convex interface,new solid atoms in the interface layer by layer growth.The newly grown crystal with the best quality and fewer defects is(100)crystal plane model.(5)In the process of silicon carbide induced crystallization,the crystal defects are mainly vacancy defects,gap atomic defects and substitution defects at the interface,and dislocation defects in the crystal.