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The use of plasma immersion ion implantation (PIII) is a relevant approach for the development of advanced solar cells technologies at lower cost (€/W p ). In this paper, we report on the development of homogeneous boron (B) doping of n-type crystalline silicon (cSi) substrate by the PIII technique. Using diborane (B 2 H 6 ) as gas precursor, various doping profiles were identified fitting the requirements for boron-doped emitters in n-type PERT solar cells. Particularly, saturation current density (J 0e ) of 50 fA/cm 2 were achieved on symmetrical samples for a 94 Ω/sg textured B-emitter passivated with SiO 2 /SiN stack. Bifacial n-type Passivated Emitter Rear Totally-diffused (n-PERT) solar cells were fabricated using the PIII technology and conversion efficiencies up to 19.8% on 239 cm 2 Cz-Si wafers were obtained. As a consequence, these results indicate that PIII can compete with beamline technology but will have lower running cost. It is therefore a promising technology to create high efficiency cSi solar cells.

Classical beam line ion implantation is limited to low energies and cannot achieve P+/N junctions requested for Compared to conventional beam line ion implantation limited to a minimum energy implantation of 200 eV, plasma immersion ion implantation (PIII) is an emerging technique to get ultimate shallow profiles (as-implanted) due to no lower limitation of energy and high dose rate. On the another hand, laser thermal processing (LTP) allows to obtain very shallow junction with no TED, abrupt profile and activated depth control. In this paper, we show the implementation of the BF3 PIII associated with the LTP. Ions from BF 3 + plasma have been implanted in 200 mm n-type silicon wafers with energies from 100 eV to 1 keV and doses from 3E14 to 5E15 at/cm2 using PULSION® (IBS PIII prototype). Then, wafers have been annealed using SOPRA VEL 15 XeCl excimer lasers (l = 308 nm, 200 ns, 15 J/pulse) with energy density from 1 to 2.5 J/cm2 and 1, 3 or 10 shots. The samples have been characterized at CEA LETI by secondary ion mass spectrometry (SIMS) combined with four points probe sheet resistance measurements.

7th International Workshop on Plasma-Based Ion Implantation, San Antonio, TX, SEP 17-19, 2003; International audience; The efficiency of plasma immersion ion implantation (PIII) is no more to prove for the realization of ultra shallow junctions (USJ) in semiconductor applications. Interest for the fabrication of submicrometer CMOS devices is well known, but the ability of PIII to implant quickly high doses at very low energy and low price makes it a good candidate for the Fabrication of solar cells. In this paper, we present results obtained by a semi-industrial prototype of PIII (PULSION(R)) designed by the French company IBS. First, metallic contamination, homogeneity, reproducibility, and SIMS profiles of ultra shallow junctions made by PULSION(R) BF3 implantation on 200-mm silicon wafers are presented. Results are compared with BF2+ implantations made on an AXCELIS NV-8200P beam line implanter and demonstrate the compatibility with semiconductor requirements. Then, results on solar cells with BF3 shallow junctions made by PIII are presented. The simulated and measured internal quality factor (IQE) with an improved behavior in blue wavelengths demonstrates the interest of PIII for this applications field. (C) 2004 Elsevier B.V. All rights reserved.