Quantitative analysis of tungsten, oxygen and carbon concentrations in the microcrystalline silicon films deposited by hot-wire CVD
In: Proceedings of the Second International Conference on Cat-CVD (Hot Wire CVD) Process, Denver, Colorado, USA, September 10-13, 2002Thin solid films 430(1-2):110-115; Jg. 430 (2003) 1-2, S. 110-115
Konferenz
- print, 18 ref
Zugriff:
In order for hot-wire chemical vapor deposition to compete with the conventional plasma-enhanced chemical vapor deposition technique for the deposition of microcrystalline silicon, a number of key scientific problems should be cleared up. Among these points, the concentration of tungsten (nature of the filament), as well as the concentration of oxygen and carbon (elements issued when vacuum is broken between two runs), should not exceed threshold values, beyond which electronic properties of the films could be degraded, as in the case of monocrystalline silicon. Quantitative chemical analysis of these elements has been carried out using the secondary ion mass spectrometry technique through depth profiles. It has been shown that for a high effective filament surface area (Sf = 27 cm2), the W content increases steadily from 5 × 1014 to 2 × 1018 atoms cm-3 when the filament temperature Tf increases from 1500 to 1800 °C. For a fixed Tf, the W content increases with the effective surface area Sf. Thus, considering our reactor geometry, the W content does not exceed the detection limit (5 × 1014 atoms cm-3) when Tf and S, are limited to 1600 °C and 4 cm2, respectively. For O and C elements, under deposition conditions of high dilution of silane in hydrogen (96%), O and C concentrations approaching 1020 atoms cm-3 have been obtained. The introduction of an inner vessel inside the reactor, the addition of a load-lock chamber and a decrease in substrate temperature to 300 °C have led to a drastic decrease in these contents down to 3×1018 atoms cm-3, compatible with the realization of 6% efficiency HWCVD μc-Si:H solar cells.
Titel: |
Quantitative analysis of tungsten, oxygen and carbon concentrations in the microcrystalline silicon films deposited by hot-wire CVD
|
---|---|
Autor/in / Beteiligte Person: | BOUREE, J. E ; GUILLET, J ; GRATTEPAIN, C ; CHAUMONT, J |
Link: | |
Quelle: | Proceedings of the Second International Conference on Cat-CVD (Hot Wire CVD) Process, Denver, Colorado, USA, September 10-13, 2002Thin solid films 430(1-2):110-115; Jg. 430 (2003) 1-2, S. 110-115 |
Veröffentlichung: | Lausanne: Elsevier Science, 2003 |
Medientyp: | Konferenz |
Umfang: | print, 18 ref |
ISSN: | 0040-6090 (print) |
Schlagwort: |
|
Sonstiges: |
|