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In this work, we present results on simultaneous formation of emitter/back‐surface field or emitter/surface passivation in a single rapid thermal cycle. We have investigated the diffusion kinetics of dopant elements like phosphorus, boron (from a doped spin‐on glass (SOD) film), aluminium (from evaporated films) or aluminium‐boron (from an A1‐B SOD film). In particular, we have shown that rapid thermal co‐diffusion of P and A1 (or A1‐B) leads to low sheet resistances, optical emitter profiles and a hig h gettering effect. Furthermore, the possibility of using the remaining SOD films as a surface passivation layer was investigated. Dark saturation current measurements as deduced from the photoconductivity decay technique demonstrate the passivation effec t of the remaining SOD film. The highest efficiency of 12.8% obtained was achieved on SOD oxide‐coated solar cells.

The rapid thermal annealing of doped (SOD) and undoped (SOG) glass films spinned onto silicon from diluted or undiluted solutions has been investigated. The dilution performed by methanol has allowed to obtain oxide films as thin as 10 nm.The optical measurements of annealed SOG films have shown that good oxide films without oxygen deficiency are achievable. The electrical characteristics of Al-gate capacitors assessed by Capacitance-voltage measurements have shown a great dependence of the water content in the range of 600–850°C before reaching a typical dielectric constant value near 3.8 at higher temperatures. Low Interface state densities values obtained at temperature up to 900°C confirm the curing effect of a rapid thermal annealing.On the other hand, we have demonstrated that the efficiency of rapid thermal diffusion from boron or phosphorus SOD films deposited on Si wafers depends on the source composition and its thickness. In particular, we have shown that it is possible to control the junction depth, the surface concentration and the minority-carrier diffusion length by varying the amount of dopant concentration in the solution, the thickness of the doped oxide film and the rapid thermal processing parameters. Futhermore, the remaining doped SOG film can play the role of an efficient oxide passivation layer.

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Limiting thermal exposure time using Rapid Thermal Processing (RTP) is now emerging as a promising simplified process for manufacturing of terrestrial solar cells in a continuous way. In this work, we present results on simultaneous formation of emitter, back-surface field and surface passivation in a single rapid thermal cycle. Spin-on dopants (SOD) solutions are used as dopant sources. Optimal emitter profiles, low sheet resistances and high gettering effect are reached. The residual SOD film is used as a surface passivation layer. Solar cells with efficiencies in the range 10 -14 % are obtained depending on temperature and time processing.