Research On The Preparation And Performance Of The AlN Thin Films Deposited By Reactive Magnetron Sputtering

Wurtzite Aluminum nitride (AlN) belongs to III–V semiconductor compounds with a hexagonal wurtzite crystal structure. Because of its high thermal conductivity, chemical stability, high hardness, high acoustic velocity, large electromechanical coupling coefficient and a wide band gap, AlN thin films have received great interest as a promising candidate electronic material for thermal dissipation, dielectric and passivation layers, surface acoustic wave (SAW) devices and photoelectric devices. In this paper, high quality AlN thin films were deposited on the 45 steel, Si and Mo substrates, respectively, by MIS800 ion beam sputtering and magnetron sputtering techniques simultaneously.Firstly, the crystallization properties and structures of AlN films deposited on the 45 steel were characterized by X-ray Diffraction (XRD) and Scanning Electronic Microscope (SEM). The results indicated that the sbustrate temperature, the concentration of Nitrogen gas and the working pressure had great effects on the crystallization properties and structures of AlN films. By introducing AlN buffer layer, the preferred orientation of films changed from (100) to (002), and the growth model changed from island-like to layer-like. These changes increased the density of films, improved the film’s crystallization quality. Our experiment results supplied a guide to yield AlN films with high quality.Secondly, the scratch test was adopted to measure the adhesion of AlN thin films deposited on different substrates; this study demonstrated that the combination in the film/underlay interface was the key factor in influencing the adhesion of AlN thin films. The adehison of the films can be improved by cleaning the sbustrate surface by low-energy ion beam, introducing the transition buffer between the interface and different technics for different substrates. The structure and stress of AlN films were influenced by the preparation method and the technics, and the properties of AlN films can be improved by employing dual targets reactive magnetron sputtering deposition method, while the temperature of underlay and working pressure were the important parameters of this method.Finally, the electronic performance of AlN films were tested by superhigh resistor test apparatus and insulate voltage test apparatus. The resistance ratio of films can be as high as 6.4×1013?m, breakdown field can be high as 1.32MV/cm. The main factors which effected the electronic performance of AlN films were ratio of Al/N and the crystallization quality of the films.