Adsorption geometry of furan on Si(1 0 0)-2 × 1

We have investigated adsorption of furan on Si(1 0 0) at room temperature using high resolution photoemission spectroscopy (PES) and near edge X-ray absorption fine structure (NEXAFS) in the partial electron yield (PEY) mode. The Si 2p, C 1s, O 1s spectra of furan on Si(1 0 0) show that furan is chemisorbed on Si(1 0 0)-2 × 1 through [4 + 2] cycloaddition. NEXAFS has been conducted to characterize the adsorption geometry of furan on Si(1 0 0). Since the π∗ orbital of CC bond showed a good angle dependence in carbon K-edge NEXAFS spectra, the angle 28 ± 2° determined from NEXAFS spectra appears to deviate from a theoretical value of 19° for the [4 + 2] cycloaddition by 9°, mostly due to the intrinsic defects on the Si(1 0 0)-2 × 1 substrate surface.