The Performance Of In_xAl_1-xN Films By Magnetron Sputtering Method

In view of a higher Schottky barrier,a stronger spontaneous polarization effect,high two-dimensional electron density and carrier concentration,In_xAl_1-xN has become the ideal material of high-power,high-frequency GaN-based d eVices and high electron mobility transistor in commercial and military.Furthermore,the changes of In content in the InxAl1-x,N thin film makes the band gap of the material continuously adjustable from 0.7 eV to 6.2 eV.Therefore,it is full of theoretical significance and practical value to study the influenceon different composition of In_xAl_1-xN films on the technological Parameter,growth mechanism and photoelectric properties of different thin films,which in order to d eVelop the corresponding data for the corresponding d eVices and corresponding sensors value.The AIN and InN thin films were grown on Si?111?substrates by using metal indium as In source,metal aluminum as Al source and nitrogen as N source,using magnetron sputtering system.Different thin film samples were pre Pared by changing the process parameters.And the crystal structure,element distribution and microstructure of the samples were analyzed by using X-ray Dispersive?XRD?,scanning electron microscopy?SEM?,energy dispersive spectroscopy?EDS?,X-ray photoelectron spectroscopy?XPS?and atomic force microscopy?AFM?.The results show that the ideal InN hexagonal prism fiber structure and the AIN film with very flat surface are pre Pared and the optimized process of the growth film is as follows:the substrate temperature is 600?,a working pressure of 0.6 Pa,an Ar and N₂ flow ratio of 20:20,and an ideal sputtering power?In:70 W;Al:250 W?.The result shows that the growth mechanism between InN and AIN films is the transition between 2D growth mode and 3D growth mode under the combined action of pressure,temperature and Ar and N₂ flow ratio.On the basis of InN and AIN,In_xAl_1-xN thin films were prepared by indium and Al double target co-sputtering,and the technological conditions for preparing different component films were investigated.Although it was found that In_xAl_1-xN was difficult to be pre Pared or the indium content was lower since the temperature was too high.How eVer the higher indium content of In_xAl_1-xN thin films was pre Pared by changing the substrate temperature,working pressure as well as Ar and N₂ ratio.Via the characterization and analysis of the experimental samples,the contents of In components were calculated at 0.88,0.69 and 0.52 respectively.Furthermore,analyzing the samples by Hall test and Raman test at room temperature,with the increase of the In composition,the electron mobility of the films decreased and the peak positions of A_i?LO?and E₂?high?of the samples were also decreased from 633.24 cm^-1 and 688.86 cm^-1 to 595.75 cm^-1 and 650.23cm^-1.Due to the change of the experimental Parameters,the energy of the sputtered Particles on the surface of the substrate is different,which affects the conversion between the energy in the film growth process.Therefore,although they are grown in the layer-island mode,various forms were obtained as well.Finally,the energy gap of different samples was calculated by three methods.The results showed that the band gap of In_xAl_1-xN samples?0.52?x?0.88?was between 0.83 eV to 2.19 eV.