PULSION?-Solar, a Efficient and Cost Effective Plasma Immersion Ion Implantation Solution for Phosphorus and Boron Doping needed for high Conversion Efficiency Silicon Solar Cells

摘要

Since several years, the use of Beamline ion implantation has been proven to allow optimization of doping profiles needed for the fabrication of crystalline silicon (c-Si) solar cells while simplifying the process flow. Nevertheless the cost and complexity of such tools, associated to the difficulty to keep a small thermal budget to make high quality Boron doping for N-type cells, has slowed down the industrial introduction of ion implantation in high volume solar cell fabrication fabs.Thanks to an implant time independent to the implanted surface, and a simple tool architecture, Plasma Immersion Ion Implantation (PIII) offers an economically efficient alternative to Beamline Ion Implantation.In this paper, after having presented PULSION?-Solar, the IBS PIII tool dedicated to solar cell fabrication, we will demonstrate state of the art characteristics on different cells type either on c-Si but also on multi crystal Si where the beneficial gettering capability allowed by POCl3 is also obtained using PIII phosphorus implantation. We will also show how the PIII doping process, thanks to its unique energy distribution, can even be more efficient than beam line, especially for boron doping, allowing lower thermal budget and co-anneal with phosphorus, simplifying even more the process flow for n-type PERT solar cells.