The influence of deposition conditions on structure and morphology of aluminum nitride films deposited by radio frequency reactive sputtering

摘要

Wurtzite aluminum nitride (2H-AlN) films were deposited on (100) silicon wafers by radio frequency (RF) magnetron reactive sputtering under various deposition conditions. The evolution of structure and morphology of AlN films were studied by X-ray diffraction, and field emission scanning electron microscopy. The preferred orientation was found to be sensitive to deposition conditions such as sputtering pressure, RF power, N_2 concentration. Gas flow rate showed no distinct influence on the preferred orientation, but the crystalline quality of the deposited film was improved with the increase of flow rate. Temperature influenced the preferred orientation in a complex way. A correlation between preferred orientation and morphology was observed. It was found that worm-like grains are favorable in films with (100) preferred orientation. Pebble-like grains are likely to grow in films with (002) preferred orientation. Pyramid cone structure prevails in films that show the existence of (101) peaks in XRD spectrum.