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In this study, a femtosecond laser etching method is proposed to pattern an aluminum nitride (AlN) film, grown by metal-organic chemical vapor deposition on sapphire. Via control of typical pulse energies, the designed pattern was precisely written in the AlN film. The morphology of the patterned structures was characterized using a three-dimensional laser scanning confocal microscope and a scanning electron microscope; crystalline quality and film strain were analyzed using a Raman spectrometer and a transmission electron microscope. The results indicate that consistent morphologies were achieved with only slight changes to the crystalline quality. The tensile stress of the AlN film was released, and the film surface was slightly compressed after laser patterning. Thus, femtosecond etching has the potential to be an in situ patterning method during film growth. [ABSTRACT FROM AUTHOR]

The self-assembly of SiC quantum dots (SiC QDs) formed on AlN films is investigated. Under optimized growth conditions, SiC QDs with a remarkably narrow size distribution on polycrystalline AlN films can be achieved with the presence of a wetting layer of SiC film by low-frequency inductively coupled plasma- (LF-ICP-) assisted magnetron sputtering. A transmission electron microscope (TEM), field-emission scanning electron microscope (FE-SEM) images, and an energy-dispersive x-ray (EDX) spectrometer clearly demonstrate that SiC QDs are formed on the polycrystalline AlN films. [ABSTRACT FROM AUTHOR]