Current noise measurements of surface defect states in amorphous silicon
Measurements of conductance fluctuations in coplanar hydrogenated amorphous silicon (a-Si:H) are reported as a function of surface etching treatments. The noise power spectrum displays a broadened Lorentzian peak, associated with surface damage by CF{sub 4} reactive ion etching (RIE), whereas surface etches using ion milling or wet chemicals remove the Lorentzian spectral feature and only a 1/f spectral form for frequency f is observed. The Lorentzian spectral feature can be explained by trapping-detrapping from surface states induced by the RIE etch, which cause fluctuations in the depletion width of the space charge region near the film surface. The thermally activated Lorentzian corner frequency is a measure of the degree of band bending and the Fermi energy at the thin film surface.
- Research Organization:
- Univ. of Minnesota, Minneapolis, MN (US)
- Sponsoring Organization:
- National Science Foundation (NSF)
- OSTI ID:
- 20107934
- Resource Relation:
- Conference: 1999 Materials Research Society Spring Meeting, San Francisco, CA (US), 04/05/1999--04/09/1999; Other Information: PBD: 1999; Related Information: In: Amorphous and heterogeneous silicon thin films: Fundamentals to devices -- 1999. Materials Research Society symposium proceedings: Volume 557, by Branz, H.M.; Collins, R.W.; Okamoto, Hiroaki; Guha, S.; Schropp, R. [eds.], 908 pages.
- Country of Publication:
- United States
- Language:
- English
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