Band bending and oxygen-induced defects in a -Si:H

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Journal of Vacuum Science and Technology, B: Microelectronics Processing and Phenomena; (USA)

DOI:https://doi.org/10.1116/1.584466· OSTI ID:5490223

Winer, K ^[1]

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1. Xerox Palo Alto Research Center, Palo Alto, California 94304 (US)

Total yield photoelectron spectroscopy and Kelvin probe measurements are used to monitor the adsorption of activated oxygen onto clean hydrogenated amorphous silicon ({ital a}-Si:H) surfaces at submonolayer coverages. Oxygen adsorption induces up to 3{times}10{sup 12} cm{sup {minus}2} occupied near-surface gap states in a band centered 5.15 eV below the vacuum level and results in an 0.25-eV downward band bending at both slightly {ital n}-type and intrinsic {ital a}-Si:H surfaces. It is proposed that the downward band bending is due to the transfer of electrons from overcoordinated surface oxygen atoms to neutral defects native to {ital a}-Si:H, which form negatively charged deep states in a near-surface accumulation layer. The surface donor character of adsorbed oxygen is contrary to its usual strong electronegativity but is analogous to the donor character of overcoordinated phosphorus atoms in the {ital a}-Si:H bulk, which also lead to the creation of negatively charged deep states. Doping and deep defect formation in {ital a}-Si:H are discussed.

• OSTI ID: 5490223
• Journal Information: Journal of Vacuum Science and Technology, B: Microelectronics Processing and Phenomena; (USA), Journal Name: Journal of Vacuum Science and Technology, B: Microelectronics Processing and Phenomena; (USA) Vol. 7:5; ISSN 0734-211X; ISSN JVTBD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ADSORPTION
DEFECTS
ELECTRON SPECTROSCOPY
ELECTRON TRANSFER
ELEMENTS
ENERGY RANGE
EV RANGE
HYDRIDES
HYDROGEN COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
OXYGEN
PHOSPHORS
PHOTOELECTRON SPECTROSCOPY
SILANES
SILICON COMPOUNDS
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES