低温化学气相沉积SiC的组成、组织结构及高温稳定性

Composition,Microstructure and Thermal Stability of Silicon Carbide Chemical Vapor Deposition at Lower Temperature

利用Ｘ射线衍射、Ａｕｇｅｒ能谱、Ｒａｍａｎ光谱、扫描电镜和透射电镜等分析手段，对低温（１０００～１３００℃）化学气相沉积ＳｉＣ的化学组成、组织结构及高温稳定性进行了分析。实验结果表明，在本实验的沉积温度范围内，沉积物是由３Ｃ型βＳｉＣ和少量４Ｈ型的αＳｉＣ组成，无游离Ｓｉ存在，这与高温条件下的实验结果存在明显差异。同时，在沉积物的表面还有Ｃｌ和Ｓ等吸附物及ＳｉＯ２氧化膜存在。所得到的ＳｉＣ均为１０１ｎｍ级晶粒。随着沉积温度的降低，晶粒尺寸减小，晶格失配度增大；经１５５０℃，５ｈ高温热处理后，出现明显的失重、晶粒长大和晶格失配度降低的现象。

In the present paper,silicon carbide was prepared by chemical vapor deposition at temperatures ranging from 1000 to 1300℃.The chemical composition,microstructure,and thermal stability of silicon carbide were examined with X ray diffraction,Auger multiple probe,Raman spectrum,scanning electronic microscope,and transmission electronic microscope.Experimental results indicated that the deposit was mainly consisted of beta silicon carbide with small alpha silicon carbide.Neither free silicon nor carbon was found.Chlorine,sulphur,and a very thin layer of silica existed on the surface of the deposit.The crystalline sizes of present deposit were in 10 1 nanometer scale.With the increase of deposition temperatures,the crystalline sizes were increased but the crystal lattice distortions were decreased.After the deposits were annealed at 1550℃ for