Wet etching and infrared absorption of AlN bulk single crystals

• Published in: Journal of semiconductors Vol. 30; no. 7; pp. 29 - 32
• Main Author: 李巍巍 赵有文 董志远 杨俊 胡炜杰 客建红
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.07.2009
• Subjects: X射线衍射; 散装; 晶体生长; 氮化铝; 红外吸收; 纤锌矿结构; 蚀刻; 铝单晶
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/30/7/073002

The defects and the lattice perfection of an AlN（0001） single crystal grown by the physical vapor trans-port（PVT） method were investigated by wet etching, X-ray diffraction（XRD）, and infrared absorption, respectively.A regular hexagonal etch pit density（EPD） of about 4000 cm-2 is observed on the（0001） Al surface of an AlN single crystal.The EPD exhibits a line array along the slip direction of the wurtzite structure, indicating a quite large thermal stress born by the crystal in the growth process.The XRD full width at half maximum（FWHM） of the single crystal is 35 arcsec, suggesting a good lattice perfection.Pronounced infrared absorption peaks are observed at wave numbers of 1790, 1850, 2000, and 3000 cm-1, respectively.These absorptions might relate to impurities O, C, Si and their complexes in AlN single crystals.