摘要
本文采用物理气相传输法(PVT)及同质外延工艺,在自发生长的6 mm×7 mm Al N籽晶片上,通过4次迭代,成功生长出高质量1英寸Al N单晶锭。将生长出的单晶锭经过切片、研磨和抛光工艺加工成1英寸低表面粗糙度的单晶片,并采用拉曼光谱仪、扫描电子显微镜、高分辨率X射线衍射仪、分光光度计对籽晶片与外延晶片进行结晶质量、位错密度以及紫外透光率等性能表征。结果表明:外延晶片的拉曼E_2(high)半高宽为2. 86 cm~(-1),(002)面XRD摇摆曲线半高宽为241 arcsec,说明晶片具有很高的结晶质量;经过同质外延4次迭代后的晶片较初始籽晶片相比质量有所下降,说明生长过程中由于非平衡生长存在缺陷的增殖;外延晶片具有极其优异的紫外透光率,深紫外265～280 nm波段下的吸收系数低至19～21. 5 cm~(-1)。
In this work,1 inch bulk Al N single crystals were homoepitaxially grown by the physical vapor transport method based on a 6 mm × 7 mm freestanding Al N seed after 4 iterations. The single crystals were sliced into wafers and then lapped/polished following the common wafering standards. The obtained wafers were characterized by Raman spectroscopy,high resolution X-ray diffraction( HRXRD),Scanning electron microscopy( SEM) and UV-Visible spectrophotometer. The Raman spectroscopy exhibits an E_2( high) full width at half maximum( FWHM) of 2. 86 cm~(-1). The symmetric HRXRD rocking curves have the FWHMs of 241 arcsec. The quality of the homoepitaxially grown crystals is slightly lower than the firstgeneration Al N seed,which indicates that defects were generated due to non-equilibrium growth conditions during the homoepitaxial growth processes. Furthermore,the optical transmission spectra data reveales that the entire wafers exhibit excellent UV transparency with the absorption coefficient of 19-21. 5 cm~(-1) in the UV range of 265-280 nm.
引文
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