[17a-B309-1~10] 17.2 Graphene

[17a-B309-6] Core-level photoelectron spectroscopy study on the buffer-layer formed in approximately atmospheric pressure argon on n-type and semi-insulating SiC(0001)

〇Fumihiko Maeda¹, Makoto Takamura², Hiroki Hibino³ (1.Fukuoka Inst. of Tech., 2.NTT BRL, 3.Kwansei Gakuin Univ.)

Keywords:buffer layer, band bending, semi-insulating SiC(0001) substrate

Using core-level photoelectron spectroscopy, we studied the surface of SiC(0001)-6√3 × 6√3R30° (buffer layer surface) formed on n-type and semi-insulating substrates via the approximately-atmospheric-pressure graphitization method. When band bending of the buffer layer on the n-type and semi-insulating substrates was estimated using the peak position of Si 2p, a reasonable value of −0.05 eV was obtained for the n-type substrate. However, for the semi-insulating substrate, the Fermi level (Ef) was located at 0.05 eV below the conduction band minimum (CBM) on the surface. This is anomalous if we interpret the change in the CBM position over Ef from the bulk to the surface to be solely induced by band bending. To interpret this situation, we propose a mechanism in which the n-type region appears near the surface of the SiC bulk under the buffer layer.