Study On HVPE Simulation And Optimization Of Reaction Parameters For Gallium Oxide Growth

Gallium oxide?Ga₂O₃?is a wide bandgap oxide semiconductor material.It is a new member of the third generation of semiconductor materials after Si C and Ga N.Ga₂O₃ has excellent photoelectric properties,good thermal stability and chemical stability.Among them,?-Ga₂O₃ thin film has high transparency in the deep ultraviolet region,which is very suitable for making ultraviolet photoelectric materials.The breakdown voltage of?-Ga₂O₃ is 8MV/cm,which is much higher than the breakdown voltage of Si C and Ga N.?-Ga₂O₃ has great potential in the application of field effect transistors,Schottky diodes and other power electronic devices.At the same time,the Ga₂O₃ material is also excellent in gas-sensing characteristics and is a candidate material for preparing high-temperature oxygen-sensitive devices.Therefore,the Ga₂O₃ materials have become a research hotspot nowdays.This paper introduces the structural characteristics,basic properties,and manufacturing processes of Ga₂O₃ materials.The simulation experiments of the process of growing Ga₂O₃ films by HVPE are performed using CFD simulation software.Compared with the traditional experimental method,the method of computer software simulation can obtain the growth of Ga₂O₃ film under different conditions by adjusting the temperature in the reaction chamber,the flow velocity of the air inlet,and the geometry of the cavity,and not only can get more information,it also greatly saved manpower and material resources.In this study,a two-dimensional model of a 6-inch Ga₂O₃ thin film growth chamber for HVPEwas established,and the physical and chemical parameters required for the simulation were calculated.By sequentially adjusting key parameters such as the inlet speed of Ga Cl,O₂ and N₂,and the distance between the nozzle and the substrate,the growth process was simulated.According to the growth rate and relative uniformity of the Ga₂O₃ thin film,the parameters of chamberhave been optimized.It is concluded that it is the most suitable for the growth of Ga₂O₃when the inlet speed of Ga Cl,O₂,and N₂are 9m/s,0.03m/s,1.8m/s respectively,and the distance between the nozzle and the substrate is 15cm.Under the above conditions,the relative uniformity of the growth rate of the Ga₂O₃ film on the substrate reaches 7.24%.The study found that the concentration distribution of O₂ above the substrate was high on both sides and low on both sides,which was caused by the large distance between the nozzle and the substrate and the high inlet velocity of Ga Cl.In addition,we carried out comparative experiments on different gas mole fractions and settings for reaction activation energy in the simulation,and found that the mole fraction of the gas has a certain effect on the parameter design of the reaction chamber.In actual experiments,the inlet speed of Ga Cl can be increased appropriately.Although the activation energy parameter has a significant effect on the average growth rate,it has little effect on the optimal design of the growth rate distribution and uniformity of the sample.