高纯半绝缘4H-SiC单晶衬底Si面外延石墨烯工艺研究

摘要

高纯半绝缘SiC衬底上获得大面积、高质量石墨烯是富有挑战性的工作,外延层石墨烯材料的确认和性能表征也至关重要.研究了高纯半绝缘衬底上制备大面积外延石墨烯的工艺以及相关工艺参数(压力、温度、工艺时间)对外延石墨烯质量的影响.通过激光拉曼光谱、原子力显微镜、场发射扫面电镜等分析,测试了石墨烯材料的大小、形态,为后续工艺的改进提供参考.在1 650℃、500 Pa压力下生长2h制备的外延石墨烯,具有更高品质和表面连续性,拉曼光谱中2D峰的半高宽(FWHM)约为34 cm-1,能够用单峰洛伦兹拟合,预示着单层石墨烯的形成.%It is a challenge to fabricate large area and high quality graphene on high purity semiinsulating SiC substrate.Meanwhile,it is important to confirm and characterize the properties of epitaxial graphene.The growth technology of large area graphene on SiC substrates was studied by examining the effects of growth pressure,temperature,and graphitization time on the quality of epitaxial graphene.The surface morphology and material structure of the epitaxial graphene were characterized with laser Raman spectroscopy,atomic force microscope,and field emission scanning electron microscopy,respectively.It is concluded that the high quality and continuous graphene material has formed on SiC at 1 650 ℃ for 2 h with a pressure of 500 Pa.The peak width at half height (FWHM) of the 2D peak in the Raman spectrum of this epitaxial graphene is about 34 cm1,and could be fit with single peak Lorenz,which predict the formation of monolayer graphene.