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金属有机物化学气相沉积法(MOCVD)是半导体材料生长的一门新技术,MOCVD材料在半导体激光器等方面有着重要作用。本文用的材料是生长在掺In半绝缘GaAs上的GaAs外延膜。用扫描电镜的阴极荧光(CL)模式观察,发现有大量黑线缺陷组成“布纹状”图形。这些黑线缺陷大致沿两个互相垂直的(110)方向,如图1,一个方向较密,另一个方向较稀疏。图2是横断面的TEM照片,显示有大量位错网络存在。有的网络从衬底一直沿伸生长到处延层,有的是外延层内产生的。平面(001)样品显示的位错网络与SEMCL像相符。用衍衬法确定这些位错主要是60°位错,是滑移形成的。X射线双晶衍射发现此材料有万分之三的晶格
Metalorganic chemical vapor deposition (MOCVD) is a new technology for the growth of semiconductor materials. MOCVD materials play an important role in semiconductor lasers and other fields. The material used in this paper is a GaAs epitaxial film grown on In-doped semi-insulating GaAs. Observed by scanning electron microscopy (CL) mode, a large number of black line defects were found to form a “pattern”. These black line defects are roughly along two directions (110) perpendicular to each other, as shown in FIG. 1, one direction is dense and the other direction is sparse. Figure 2 is a cross-sectional TEM photograph showing the presence of a large number of dislocation networks. Some networks have been extended from the substrate along the extension of the extended layer, and some are generated within the epitaxial layer. The plane (001) sample shows dislocation networks consistent with SEMCL images. Using diffraction method to determine these dislocations is mainly 60 ° dislocation, is slip formed. X-ray double crystal diffraction found that the material has a three-ten-thousandth lattice