Ultra-long AlN Crystal Whiskers Grown by Physical Vapor Transport Method

The physical vapor transport method growth technology of AlN single crystal whisker was investigated. Through adjustment and control of growth temperature and nitrogen pressure,three kinds of AlN crystal whisker were acquired, whose morphologies were hexagonal prism, ladder and strip respectively. The prism whisker was 35 mm long and had a diameter of 1 μm. The relationship between growth morphology,crystallization orientation and growth condition of AlN crystal whiskers was studied by means of SEM and XRD. Under lower temperature lower pressure and higher supersaturation degree,AlN whisker intends to grow along the direction of [0001] and develops into thin hexagonal prism. When temperature rises,the priority growth plane transforms to { 11-02} plane and the morphology changes into straight ladder. Continue to increase pressure,{ 101-0} plane becomes the priority growth plane and the whisker grows into curly strip shape.