【摘要】 我们利用透射X射线形貌技术观察了 n-GaAs衬底及 GaAs-Al_xGa_1-xAsDH外延片中的晶体缺陷,并且用高分辨率形貌技术与金相技术进行了对照.证明了普通X射线形貌像中的衬度是由晶体缺陷形成的.根据X射线形貌像,我们对n-GaAs衬底及GaAs-AlxGa_1-xAs DH外延片中的缺陷密度作出了评价. 采用常规的DH液相外延技术及质子轰击条形的器件工艺,将我们研究的衬底制成了激光器.测试结果表明:器件的成品率和质量与我们对衬底中缺陷密度的评价完全对应.利用X射线形貌技术挑选出的低缺陷密度的衬底,我们获得了很多性能优良的长寿命激光器.更多还原

【Abstract】 Defects in GaAs substrates and GaAs-Al_x Ga_1-xAs DH （double heterostructure）epitaxial wafers have been observed by means of transmission X-ray topography. Highresolution X-ray topography and metallographic techniques prove that the contrastin X-ray topographic photos is produced by crystal defects.An evaluation for thedensity of the defects in GaAs substrates and GaAs-Al_x Ga_1-xAs DH wafers is givenaccording to the X-ray topographic photos. The stripe lasers have been made by conventional LPE （liquid phase epitaxy）and proton bombardment. Measurement of the characteristics of the lasers shows thatthe device yield and quality correspond to our evaluation from X-ray topographyfor the density of the defects in the substrates and epitaxial wafers.更多还原