High quality AlGaN grown on a high temperature AlN template by MOCVD

• 作 者: 闫建昌 王军喜 刘乃鑫 刘喆 阮军 李晋闽
• 机 构: Semiconductor Lighting R&D Center,Institute of Semiconductors,Chinese Academy of Sciences,
• 出 处: 半导体学报
• 发表日期: 2009年10期
• 关键词: AlGaN template FWHM relaxation screw MOCVD roughness sapphire ultraviolet recipr

A high temperature AlN template was grown on sapphire substrate by metalorganic chemical vapor deposition.AFM results showed that the root mean square of the surface roughness was just 0.11 nm.Optical transmission spectrum and high resolution X-ray diffraction(XRD)characterization both proved the high quality of the AlN template.The XRD(002)rocking curve full width at half maximum(FWHM)was about 53.7 arcsec and(102)FWHM was about 625 arcsec.The densities of screw threading dislocations(TDs)and edge TDs were estimated to be～6×106 cm?2 and～4.7×109 cm?2.AlGaN of Al composition 80.2%was further grown on the AlN template.The RMS of the surface roughness was about 0.51 nm.XRD reciprocal space mapping was carried out to accurately determine the Al composition and relaxation status in the AlGaN epilayer.The XRD(002)rocking curve FWHM of the AlGaN epilayer was about 140 arcsec and(102)FWHM was about 537 arcsec.The density of screw TDs was estimated to be～4×107 cm-2 and that of edge TDs was～3.3×109 cm-2.These values all prove the high quality of the AlN template and AlGaN epilayer.

A high temperature AlN template was grown on sapphire substrate by metalorganic chemical vapor deposition. AFM results showed that the root mean square of the surface roughness was just 0.11 nm. Optical transmission spectrum and high resolution X-ray diffraction (XRD) characterization both proven the high quality of the AlN template. XRD (002) rocking curve full width at half maximum (FWHM) was about 53.7 arcsec and (102) FWHM was about 625 arcsec. densities of screw threading dislocations (TDs) and edge TDs were estimated to be ~ 6 × 10 6 cm 2 and ~ 4.7 × 10 9 cm 2 2. AlGaN of Al composition 80.2% was further grown on the AlN template. RMS RMS of the surface roughness was about 0.51 nm. XRD reciprocal space mapping was carried out The exact composition of the AlGaN epilayer. XRD (002) rocking curve FWHM of the AlGaN epilayer was about 140 arcsec and (102) FWHM was about 537 arcsec. The density of screw TDs was estimated to be ~ 4 × 107 cm-2 and that of edge TDs was ~ 3.3 × 109 cm-2. These values ​​all prove the high quality of the AlN template and AlGaN epilayer.