The influence of Cr-doping on the microstructure and properties of aluminum nitride (AlN) films has been investigated by means of x-ray diffraction, transmission electron microscopy, x-ray absorption near edge structure, piezoelectric force microscopy and x-ray photoelectron spectroscopy. The results indicate that Cr 3+ steadily substitutes for Al 3+ in AlN wurtzite lattice without any precipitated secondary phase formation. Moderate Cr-doping has a profound influence on the enhancement of (0 0 2) texture and crystallinity of Cr : AlN films. The residual stress for the Cr : AlN films changes from tension to compressive stress with increasing Cr concentration. The Al 0.937 Cr 0.063 N film is almost stress-free and has a piezoelectric constant of −7.1 pm V −1 which is 73% higher than that of the undoped AlN film (−4.1 pm V −1 ). Besides the enhancement of (0 0 2) texture and crystallinity of the Cr : AlN films, the decrease in Al-polarity regions and the resultant increase in the net polarity orientation by Cr-doping also contribute to the increase in AlN piezoelectric response.
No takes yet. Share an insight, caveat, or question.
Luo et al. (2009) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: