Photoemission spectroscopy of heterojunctions of hydrogenated amorphous silicon with silicon oxide and nitride

Journal Article · Wed Feb 15 04:00:00 EST 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.3801· OSTI ID:6439521

Yang, L; Abeles, B; Eberhardt, W; Stasiewski, H; Sondericker, D

The growth and electronic structure of a-Si:H/a-SiN/sub x/:H and a-Si:H/a-SiO/sub x/:H heterojunctions have been studied by photoemission spectroscopy. Si 2p core-level photoemission was used to profile the chemical composition microscopically across the interfaces. With the exception of the SiO/sub x/-on-Si interface, which due to initial plasma oxidation is graded over approx.3 A, the interfaces are atomically abrupt. The offset energies between the a-Si:H valence-band edge and that of a-SiN/sub x/:H and a-SiO/sub x/:H, determined by valence-band photoemission, are 1.2 and 4.0 eV, respectively. Based on the fact that the offset energy is independent of a-Si:H layer thickness down to monolayer dimensions, we concluded that hole wave functions in a-Si:H are extremely localized. From the variation of the intensity of the Si-H bonding peak, located at approx.7 eV below the Fermi level, as a function of a-Si:H overlayer thickness, we determined that there are approx.2 x 10/sup 15/ cm/sup -2/ extra H atoms incorporated at the interface region to compensate for the large lattice mismatch at the interface. The invariance of the Si L/sub 2,3/ absorption edge with a-Si:H overlayer thickness indicates that the range of the core-hole exciton is less than 6 A.

• Research Organization: Exxon Research and Engineering Company, Clinton Township, Route 22 East, Annandale, New Jersey 08801
• OSTI ID: 6439521
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:6; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
AMORPHOUS STATE
BREMSSTRAHLUNG
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
DEPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
EXCITONS
FUNCTIONS
GROWTH
HETEROJUNCTIONS
HOLES
HYDRIDES
HYDROGEN COMPOUNDS
JUNCTIONS
NITRIDES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PNICTIDES
QUASI PARTICLES
RADIATIONS
SEMICONDUCTOR JUNCTIONS
SILANES
SILICON COMPOUNDS
SILICON NITRIDES
SILICON OXIDES
SPECTROSCOPY
SURFACE COATING
SYNCHROTRON RADIATION
ULTRAHIGH VACUUM
WAVE FUNCTIONS