Preparation And Characterization Of AlInN Films By Magnetron Sputtering

Since III-V semiconductor materials have a wider band gap, higher luminous efficiency, higher quantum efficiency, higher radiation resistance, and they also have high temperature resistance, acid properties, so they are widely used in high-ultraviolet laser (LD), light-emitting diode (LED) and high electron mobility transistor (HEMT). Therefore, Ⅲ-Ⅴ semiconductor materials research has been the hot spot in recent years. Among Ⅲ-Ⅴ semiconductor materials, Al1-xInxN material, as a new ternary alloy compounds, is to become the focus of researchers attention.Compared with other III-V nitrides, Al1-xInxN has the same crystal structure. It is the hexagonal wurtzite structure. With the different components of the aluminum, the band gap has a very large range of variation, from ultraviolet to infrared. However, in the actual preparation process, AlN growth requires high temperatures and low Ⅴ/Ⅲ flow ratio, but InN requires low temperatures and high Ⅴ/Ⅲ flow ratio and it decomposes at high temperatures. Moreover, they are quite different in lattice constant and thermal stability, which make it very difficult to grow high-quality Al1-xInxN films. In this experiment, we used PEMOCVD to grow AlN films, used magnetron sputtering to grow Al1-xInxN films, and explored the effects of different preparation conditions on the properties of the films structure, composition, surface morphology and optical properties.This paper research and results are:1.Used PEMOCVD method, the high-purity trimethylaluminum Al(CH3)3(purity99.9999%) as the aluminum source, the high-purity NH3(purity99.9999%) as nitrogen source, the high purity N2(purity99.9999%) as the carrier gas, the sapphire (0001) as substrate, the growth temperature were700℃900℃, the flow pressure of the reaction chamber was2.5Torr, the ratio of the aluminum source and ammonia gas were200/1to1000/1, we prepared a series of AlN films.Used XRD, SEM, AFM and transmission spectrum to ana-lyze the films’ properties, we obtained the optimal growth conditions of usin gPEMOCVD prepared AlN:growth temperature was800℃, Ⅴ/Ⅲ flow rati owas1000/1.Compared with the AlN films prepared by MOCVD system, PE M-OCVD can effectively reduce the growth temperature, and suppress vaporp h-ase reaction.2. Used magnetron sputtering method, the target materials’Al and In atomic ratio were8:2and2:8, we used quartz as substrate, high purity argon gas (purity99.9999%) and high purity nitrogen (purity99.9999%) as working gas, prepared five groups of samples. Testing found that the temperature and pressure increase would lead to a decline of indium in the films, which may due to the incorporate efficiency decline of indium atoms at the high temperatures; indium atoms occured more frequently collision when the high pressure, the amount of the indium atoms arriving to substrate would reduce, resulted indium atoms decreased in the films. In addition, we used Al2In8target material, studied the effects of different N2and Ar flow ratio, the result showed that the increase of N2would enhance the reaction between nitrogen atoms and the metal atoms, but in a pure nitrogen atmosphere, the target materials surface might formed nitride, it might affect the subsequent deposition.