蓝宝石上AlN基板的MOCVD外延生长

Epitaxial Growth of High-quality AlN Template on Sapphire Substrate by Metal Organic Chemical Vapor Deposition

结合AlN成核缓冲层技术和NH3流量调制缓冲层方法,采用MOCVD在(0001)面蓝宝石衬底上生长了AlN基板,用扫描电镜、原子力显微镜及X射线衍射仪对样品进行了表征,结果表明基板无裂纹,其平均粗糙度为0.35nm,(0002)和(1012)回摆曲线FWHM分别为37″和712″。详细论述了AlN基板的生长模式、位错行为和应力释放途径。

Combining the technique of AlN nucleation buffer layer with the method of NH3 flow rate modulated buffer layer,high-quality thick AlN templates with atomically flat surface were grown on（0001）sapphire substrate by metal organic chemical vapor deposition（MOCVD）.The scanning electronic microscope（SEM）,the atomic force microscope（AFM）and high-resolution X-ray diffractometer（XRD）were used to characterize the samples.Experimental results show the surface of the AlN templates is crack-free,the root mean square（RMS）value is 0.35 nm,and the full-width at half-maximums（FWHMs）of X-ray rocking curves（XRC）for（0002）plane（ω-scan）and（1012）plane（ω-scan）are 37 arcsec and 712 arcsec,respectively.The dislocation behavior,stress and growth mode of the AlN templates are investigated in detail.