|
Stable physical and chemical properties of aluminum nitride AlN films have high mechanical strength and good insulation properties, direct wide band gap, high thermal conductivity, low thermal expansion coefficient, widely used in acoustic surface wave devices, microelectronics and optics, Preparation of AlN films has caused widespread concern and interest. In this paper, the AlN thin films prepared by pulsed laser deposition method, by optimizing the laser energy, the growth temperature, environment bias conditions, preparation of different preferred orientation of the AlN films, respectively, using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy , scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy instrument to detect the degree of crystallinity of the sample, the structural properties of the surface topography. First, under different laser energy conditions, p-Si (100) substrate preparation (110) preferential orientation of AlN films, by using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and other instruments of the samples were tested, the results showed that the laser energy 600mJ/puls, the best prepared AlN thin crystalline surface preferred orientation best plane showed isotropic, not epitaxial growth. Second, select the laser energy the 600mJ/puls of changing the substrate temperature, The results showed that when the temperature of 600 ° C, AlN film preferred orientation of the (110) direction; when the temperature is less than 400 ° C, AlN film is no longer the (110) direction preferred orientation, but the direction of (002) preferred orientation, the direction of preferred orientation of the AlN film (002) when the substrate temperature is 250 ° C strongest, can also be grown into and used under the same conditions, and the quartz and sapphire substrate (002 AlN thin films) the direction of the preferred orientation. Finally, the AlN thin film was prepared with different environments bias, the results show that when the N2 bias is greater than 2 × 10-4Pa, the prepared AlN film crystallized under high vacuum conditions in order to prepare a preferred orientation of the AlN film. The article discusses research were prepared under different conditions of different preferential orientation of the AlN thin film, through the study showed that the most important conditions of the AlN thin film by pulsed laser deposition Preparation: the kinetic energy of AlN plasma (plume) determines the size of the degree of crystallinity and the preferential orientation , the greater the kinetic energy, the higher the degree of crystallinity, the kinetic energy is smaller, less conducive to crystallization. Were prepared by this thesis (110) and (002) preferred orientation of the AlN film. For the next step in the application of research to provide effective protection.
|