Preparation And Gas Sensitivity Of Doped In_xAl_1-xN Thin Films By Magnetron Sputtering

In_xAl_1-xN is a third-generation semiconductor material.Because it has a forbidden band width continuously adjustable in the range of 0.7 to 6.2 eV,the critical breakdown voltage is high,the radiation resistance and chemical stability are good,the thermal conductivity is high,and the heat is high.The advantages of good stability,which make it can be used in electronic equipment under harsh conditions,has become a research hotspot in the field of sensing in recent years.The implantation of Si ions can replace the position of In or Al in the In_xAl_1-xN series thin film,making its carrier concentration increase to improve its performance.At present,there are few reports of Si-doped In_xAl_1-xN series thin films.Therefore,preparation and research of Si-doped In_xAl_1-xN materials are imminent.In this paper,Si-doped InN,AlN and In_xAl_1-xN thin films were prepared in magnetron sputtering system using metallic In,metallic Al and ceramic Si₃N₄ targets.The effects of four process parameters such as substrate temperature,Si₃N₄ target power,Ar:N₂ flux ratio,and In target power on the growth of the Si-doped InN thin film were studied.The optimized process parameters of the prepared thin film were obtained,and Gas sensitivity properties of prepared Si-doped InN were studied.It was found that the optimal preparation conditions of Si-doped InN were:substrate temperature 500?,Si₃N₄ target power 40 W,Ar:N₂ 20:10,In target power70 W,gas sensing results,different preparation processes,The sensitivity of materials to ethanol is also different,and the process conditions with the highest peak gas sensitivity at different test temperatures are found,and the most stable preparation conditions for gas sensitivity are also found as the test temperature changes.The Si-doped AlN thin films were studied for four processing parameters such as working pressure,Si₃N₄ target power,Ar:N₂ flow ratio,and In target power at a certain substrate temperature.The test showed that the Si-doped AlN was optimized.The preparation conditions are pressure 0.6pa,Si₃N₄ target power 60 W,Ar:N₂ 20:10,Al target power 300 W,and the mechanism analysis of the gas sensitivity test result can be concluded that the materials of different preparation processes have different sensitivity to ethanol,and the process conditions with the highest peak gas sensitivity under different test temperatures were found,and the most stable preparation conditions for gas sensitivity were also found as the test temperature was changed.Undoped and Si-doped In_xAl_1-xN thin films were prepared using the above targets.The effects of Ar:N₂ flux ratio on the growth of In_x Al_1-xN thin films were studied at 500? and 600?.The optimum Ar:N₂ ratio was 20 The effect of pressure on the growth of In_xAl_1-xN films was studied under the conditions of 20:20 and the optimized working pressure was found to be 0.6 Pa.Then the effect of Si₃N₄ target power on the growth of Si-doped In_xAl_1-xN thin films was studied.The gas-sensitivity,electrical properties,PL spectra and Raman spectra of the prepared thin film materials were studied.Gas-sensing results show that the gas-sensitivity of Si-doped In_xAl_1-xN films is better than that of undoped In_xAl_1-xN films.The electrical performance test shows that the concentration of Si-doped In_xAl_1-xN thin-film carriers increases by two.Order of magnitude;PL spectrum can be found with the increase of Si content In_xAl_1-xN film peak emission;Raman spectrum found that after Si doping E2?high?and A1?LO?have shifted to the right,indicating that the film the stress becomes larger,combined with XRD and SEM results revealed that the nano-filamentous fluffy structure is the root cause of gas-sensitivity enhancement.