Low temperature growth of c-axis oriented A1N films on gamma-LiAlO_2 by radio frequency magnetron sputtering

摘要

Aluminum nitride (AlN) films were prepared on gamma-LiAlO_2 substrates by radio frequency (rf) magnetron sputtering. The influence of substrate temperature (T_s) and nitrogen (N_2) concentration on film growth was investigated. The X-ray diffraction (XRD) results reveal that highly c-axis oriented A1N films can be obtained in the temperature range from room temperature (RT) to 300 deg C. A smoother surface and a crystalline quality decrease with increasing N_2 concentration have been observed by XRD and atomic force microscopy (AFM) for the films deposited at lower substrate temperature. On the contrary, the degradation of the surface smoothness and the higher crystalline quality can be observed for the films deposited at a higher substrate temperature with N_2-rich ambient. The growth mechanism which leads to different crystalline quality of the films is discussed.