Photoconductive polycrystalline silicon films on glass obtained by hot-wire CVD
- Ecole Polytechnique, Palaiseau (France). Lab. de Physique des Interfaces et des Couches Minces
Textured polycrystalline silicon films with columnar structure have been deposited on glass at low temperature (400--550 C) and high deposition rate (10 to 15 {angstrom}/s) by hot-wire chemical vapor deposition using SiH{sub 4}-H{sub 2} gases. The homogeneity of the deposited layer is {+-}5% on a 8 cm diameter. As deposited films have a poor photoconductivity. However hydrogen confinement in the films during the deposition or after the deposition is found to be the key for obtaining {micro}c/poly-Si with a significant diffusion length. Eventually reasonable values of the mobility lifetime product (>10{sup {minus}7} cm{sup 2}/V) are obtained by in situ hydrogen passivation of poly-Si films after deposition. Efficient shifting of the Fermi level is achieved by in situ B or P doping. The incorporation of boron in poly-Si network strongly influences the morphology and the crystalline structure. Undoped films have a Hall mobility of 14 {+-} 5 cm{sup 2}/V.s which decreases versus the carrier concentration.
- OSTI ID:
- 527647
- Report Number(s):
- CONF-960401--; ISBN 1-55899-323-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Impulse photoconductance of thin-film polycrystalline silicon
Plasma deposition of wide gap, highly photoconductive a-Si:H thin films from disilane-helium mixtures