Growth and characterization of InxAl1−xN films on silicon substrate by magnetron sputtering method

Abstract

In this paper, InxAl1−xN films were prepared on silicon substrate by magnetron sputtering method. By changing the sputtering conditions of InxAl1−xN films such as substrate temperature, working pressure, gas flow ratio, the films with different crystalline and surface microstructure were prepared which lead to different performances of the films. The crystalline of the films was measured by x-ray diffraction (XRD), and the surface morphology and roughness of the films was characterized by scanning electron microscope (SEM). The results showed that the microstructure of InxAl1−xN film grown when the substrate temperature, the working pressure and the flow ratio of Ar and N2 are 600 °C, 0.6 Pa and 20:20 sccm respectively, is best in as-prepared InxAl1−xN films under different processing conditions, the indium content of the film is x = 0.69, and the preferred crystalline orientation of the film is (002) planes. The properties of InxAl1−xN films were measured by Hall test system and Raman analysis instrument. Hall test results showed that the mobilities of the films are between 300 cm2 V−1s−1 and 800 cm2 V−1s−1, and the carrier concentrations are between 9.8 × 1017 cm−3 and 3.2 × 1019 cm−3. Raman analysis indicated that the film has obvious A1(LO) and E2(high) optical phonon modes. In a word, the films prepared under optimized conditions have good electrical properties and less stress, so InxAl1−xN films can have great potential to be used for high-frequency devices.