SI K X-RAY-ABSORPTION SPECTRA OF SINGLE-CRYSTAL SI AND AMORPHOUS SIO2

Fine structures near the Si K-absorption edges of single-crystal Si and amorphous SiO2 were measured for well-characterized films by a transmission method with a high-resolution double-crystal spectrometer. The spectrum of single-crystal Si was not affected by the changes of the angle between the polarization vector and the crystal axis. Both single-crystal Si and amorphous SiO2 showed strong absorption lines near the edges. Energies of the K-absorption edges were determined to be 1840.3 and 1846.1 eV for single-crystal Si and amorphous SiO2, respectively. The edge structure of single-crystal Si shows features related to the theoretical empty;conduction-band structure of Si. In amorphous SiO2, the strong absorption line can be interpreted in terms of the excitonic state.