利用双低温缓冲层和插入应变超晶格技术制备高质量InP-on-GaAs复合衬底的MOCVD生长

提出一种结合双低温缓冲层和应变超晶格优势的高质量InP-on-GaAs复合衬底制备技术．研究发现LT-InP/LT-GaAs的双低温缓冲层比单一低温InP缓冲层的聚集应变的效果更为显著．并且，双低温缓冲层中的低温GaAs层存在一个最优生长厚度．当低温InP生长厚度一定，低温GaAs层的生长厚度达到优化生长厚度时，LT-InP/LT-GaAs双低温缓冲层能达到调节应变的最佳状态．最后，通过插入InGaP/lnP应变超晶格，并且优化其在外延层中的插入位置．得到了高质量的InP-on-GaAs的复合衬底，2μm厚的lnP外延层XRD-ω/2θ扫描的半高宽小于200．

Growth of High-Quality InP-on-GaAs Quasi-Substrates Using Double Low-Temperature Buffers and Strained Layer Surperlattices by MOCVD

We investigate the growth of InP-on-GaAs combined with the advantages of double low-temperature (LT) buffers and strained layer surperlattices (SLSs). It is found that LT-InP/LT-GaAs double LT buffers are more effective for strain accommodation than a LT-InP single buffer in InP-on-GaAs. On the other hand, there is an optimal thickness for LT-GaAs for a given thickness of the LT-InP layer,at which the double LT buffers can reach the best state for strain adjustment. Furthermore, the position of insertion of SLSs should be carefully designed because the distance above the InP/ buffer interface plays an important role in threading dislocation interactions for dislocation reduction. As a result,the den-sity of threading dislocations in the lnP epilayer is markedly reduced. X-ray diffraction measurements show that the full width at half maximum of the ω/20 rocking curve for the 2tμm-thick InP epilayer is less than 200.