Improvement of epitaxial graphene on silicon by use of vicinal Si(111) substrates

傾斜Si(111)基板を用いたシリコン上でのエピタキシャルグラフェンの改良

原本 直樹*; 猪俣 州哉*; 高橋 良太*; 吉越 章隆 ; 寺岡 有殿; 吹留 博一*; 末光 眞希*

Haramoto, Naoki*; Inomata, Shuya*; Takahashi, Ryota*; Yoshigoe, Akitaka; Teraoka, Yuden; Fukidome, Hirokazu*; Suemitsu, Maki*

The graphene-on-silicon (GOS) process, in which epitaxial graphene (EG) is formed on Si substrates via thermal conversion of the top surface of an SiC thin film formed on Si substrates, is now viewed as one of the key technologies to introduce graphene into Si technology. We have in this study conducted a GOS formation on vicinal Si(111) substrates and have actually found improvement in the quality of 3C-SiC (111) thin film as well as of EG. It is confirmed from the X-ray diffraction analysis that a 3C-SiC(111) thin film grows on the vicinal Si(111) substrate. A rocking curve's full-width-half-maximum (FWHM) value of XRD decreases by about 13%, proving improvement in the crystallinity of the 3C-SiC film. We next annealed the films at 1523 K in high vacuum to form graphene at the top layer. According to Raman spectra for on-axis and off-axis Si substrates, we clearly observed decrease of the defect-related D peak.