RESEARCH ON NEW QUANTUM FUNCTIONAL MATERIALS BY SEMICONDUCTOR/INSULATOR/METAL HYBRID STRUCTURES

为了实现半导体/绝缘体/金属这种新型量子功能材料的混杂结构，传统的生长技术是无能为力的。异质界面必须控制在一个单层精度。我们在OMVPE系统中开发了一种新的反应器结构，它有4个桶，避免了源气体的混合，并在每个桶中引入不同的气体。衬底以旋转或来回的方式移动。为了测试新的生长系统的基本性能，我们生长了InP、GaAs、GaP、InGaAs和AlGaP，证实了每一层外延层的高质量。成功地生长了InP/InAs/InP应变层状超晶格，需要改变不同的V族源气体而不相互混合。用多个SSD和高聚焦的SOR X射线成功地对InP中一个或更少的InAs进行了荧光检测EXAFS，并揭示了InP中As原子周围的局域结构。用价力场模型模拟了InP的晶格弛豫过程，阐明了一个非常缓慢的过程。X射线CTR散射技术被成功地应用于InP中1个分子或1/10个分子的InAs，清晰地揭示了As在InP中的分布。用该技术研究了V族气孔在异质界面上的交换过程。

To realize such a hybrid structure as smiconductor/insulator/metal for a new quantum functional materials, conventional growth techniques are of no use. The hetero-interface must be controlled to one monolayr accuracy. We have developed a new reactor structure in OMVPE system with 4 barrells where intermixing of source gases are avoided and different gases are introduced to each barrell. Substrate travels rotationally or in a back-and forth mode. To test the basic capability of the new growth system, InP,GaAs, GaP,InGaAs and AlGap were grown and a high quality of each epitaxial layr was confirmed. Strained-layr superlattices of InP/InAs/InP where different group-V source gases are required to change without intermixing with each other were successfully grown.Fluorescence-detected EXAFS for one monolayr, or less, of InAs in InP were successfully conducted with multiple SSDs and highly focused SOR X-rays, and local structures around As atoms in InP were revealed. The lattice relaxation processes were simulated by Valence-Force Field model and a very slow process was clarified.X-ray CTR scattering technique was successfully applied to one momolyer or 1/10 of momolayr of InAs in InP and the profiles of As distributions in InP were clearly revealed to an atomic level accuracy. Exchange processes of the group-V stoms at the hetero-interfaces were investigated by this technique.