Grain-boundary states and hydrogenation of fine-grained polycrystalline silicon films deposited by molecular beams
| Autor: | D. Jousse, S. L. Delage, S. S. Iyer |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Silicon
Condensed matter physics General Chemical Engineering Fermi level Doping Dangling bond General Physics and Astronomy chemistry.chemical_element engineering.material symbols.namesake Polycrystalline silicon chemistry Electrical resistivity and conductivity symbols engineering Grain boundary Order of magnitude |
| Zdroj: | Philosophical Magazine B. 63:443-455 |
| ISSN: | 1463-6417 1364-2812 |
| DOI: | 10.1080/13642819108205949 |
| Popis: | The energy distribution of grain-boundary states is determined for polycrystalline silicon films grown under ultra-high vacuum conditions. Conductivity and electron spin resonance measurements on n-type films reveal both exponential bandtails and deep gap states corresponding to disorder-induced gap states and dangling-bond defect levels (D° and D−). The latter are responsible for the pinning of the Fermi level observed at moderate doping. Both experimental techniques agree with a location of the D− level at E C-0.30 eV and the D° level at E C-0.65eV ± 0.05eV. It is shown that a hydrogen-plasma treatment at 500°C reduces the dangling-bond density by an order of magnitude and that it also yields a conduction bandtail twice as steep. The replacement of weak Si-Si bonds by more energetic Si-H bonds would explain the steeper bandtails. This view is supported by absolute measurements by nuclear reaction showing that the hydrogen content exceeds by two orders of magnitude the original dangling-bond den... |
| Databáze: | OpenAIRE |
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