Realization of ultra shallow junctions by PIII: application to solar cells

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®) designed by the French company IBS. First, metallic contamination, homogeneity, reproducibility, and SIMS profiles of ultra shallow junctions made by PULSION® BF 3 implantation on 200-mm silicon wafers are presented. Results are compared with BF 2 + implantations made on an AXCELIS NV-8200P beam line implanter and demonstrate the compatibility with semiconductor requirements. Then, results on solar cells with BF 3 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.