▎ 摘 要
We produced epitaxial graphene under a moderate pressure of 4 mbar (about 400 Pa) at temperature 1600 degrees C. Raman spectroscopy and optical microscopy were used to confirm that epitaxial graphene has taken shape continually with slight thickness variations and regularly with a centimeter order of magnitude on 4H-SiC (0001) substrates. Then using X-ray photoelectron spectroscopy and Auger electron spectroscopy, we analyzed the chemical compositions and estimated the layer number of epitaxial graphene. Finally, an atomic force microscope and a scanning force microscope were used to characterize the morphological structure. Our results showed that under 4-mbar pressure, epitaxial graphene could be produced on a SiC substrate with a large area, uniform thickness but a limited morphological property. We hope our work will be of benefit to understanding the formation process of epitaxial graphene on SiC substrate in detail.