A new large area very high frequency (VHF) reactor for the high rate deposition of microcrystalline silicon for thin film solar cell applications

• Unité de recherche: INNOSUISSE
• Numéro de projet: 6947.1;6 EPRP-IW
• Titre du projet anglais: A new large area very high frequency (VHF) reactor for the high rate deposition of microcrystalline silicon for thin film solar cell applications

Description succincte (Allemand)

A new large area very high frequency (VHF) reactor for the high deposition of microcrystalline silicon for thin solar cell applications

Description succincte (Anglais)

A new large area very high frequency (VHF) reactor for the high rate deposition of microcrystalline silicon for thin film solar cell applications

Résumé des résultats (Abstract) (Anglais)

A novel very high frequency (VHF) plasma source shall be applied for large area (1m2) deposition of amorphous and microcrystalline silicon for thin film solar cell production. The use of plasma excitation frequencies (up to 100 MHz) higher than the standard 13.56 MHz excitation frequency allows to substantially increase the plasma density and gas dissociation rates without the drawback of high ion energy bombardment of the substrate and consequent damaging. Therefore higher deposition rates at good device quality can be attained. The crucial problem in very high frequency (VHF) plasma reactors, the non-uniform voltage on the RF electrode, is solved by using adequately shaped electrodes. The proof of principle of this new reactor has up till now only been made in non-reactive plasmas. In the present project, the novel RF reactor design shall be used for the first time in applications, in particular for solar cell production. The aim is to have at the end of the project a high density RF reactor operating at elevated excitation frequencies allowing industrial high rate deposition of amorphous and microcyrstalline (micromorph) silicon with a uniformity of 5-10% on large area substrates relevant for solar cells (typically 1x1 m2).