Thickness-dependent change in the valence band offset of the SiO{sub 2}/Si interface studied using synchrotron-radiation photoemission spectroscopy

Journal Article · Sun Aug 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4961220· OSTI ID:22598888

Oshima, M. ^[1]

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1. Department of Applied Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan)

We have studied the thickness-dependent change in the valence band offset (VBO) of the SiO{sub 2}/Si(001) interface using synchrotron-radiation photoemission spectroscopy with soft and hard X-rays. The SiO{sub 2}-film thickness (T{sub ox}) and X-ray irradiation time (t{sub irrad}) were systematically parameterized to distinguish between the “intrinsic” T{sub ox} effects in the VBOs and the “extrinsic” differential charging phenomena in SiO{sub 2} films on Si substrates. The results revealed that at a spontaneous time (t{sub irrad} ≈ 5 s) that suppresses the differential charging phenomena as much as possible, the experimental VBO abruptly increases as a function of T{sub ox} and gradually saturates to the traditional VBO value range determined by the internal photoemission and photoconduction measurements. This effect is not attributed to the differential charging phenomena, but rather it is attributed to the “intrinsic” T{sub ox}-dependent change in the VBO. The two possible physical behaviors include electronic polarization and image charge. We have derived the electronic polarization contribution from experimental data by carefully describing the effects of the long-range image charges based on the classical dielectric-screening model.

• OSTI ID: 22598888
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DIELECTRIC MATERIALS
FILMS
HARD X RADIATION
IMAGES
INTERFACES
IRRADIATION
PHOTOELECTRON SPECTROSCOPY
PHOTOEMISSION
POLARIZATION
SCREENING
SILICA
SILICON OXIDES
SUBSTRATES
SYNCHROTRON RADIATION
SYNCHROTRONS
THICKNESS
VALENCE