Patterning by Selective Etching of Poly-Silicon Using a High Etch Rate Single Sided Gaseous Process

Laurent Clochard; David Young; Mingzhe Yu; Ruy Sebastian Bonilla

doi:10.52825/siliconpv.v2i.1317

Authors

Laurent Clochard Nines Photovoltaics https://orcid.org/0009-0001-3833-3332
David Young National Renewable Energy Laboratory
Mingzhe Yu University of Oxford
Ruy Sebastian Bonilla University of Oxford https://orcid.org/0000-0002-5395-5850

DOI:

https://doi.org/10.52825/siliconpv.v2i.1317

Keywords:

TOPCon, Patterning, Etching, Solar Cell, Selectivity, Dry Etching, Gas-Phase Etch

Abstract

This paper presents etching process developments using a single-side gaseous etch process based on the thermal reaction of poly-Silicon and the etching gas (molecular fluorine), that results in a high etching selectivity between layers, and a high etching rate. This work was carried out in the context of the development of solar cell architectures beyond PERC and TOPCon, where more sophisticated etching steps are required in order to accurately pattern poly-silicon layers across the wafer surface.

Downloads

Download data is not yet available.

References

[1] F. Feldmann, C. Reichel, R. Müller and M. Hermle, "Si solar cells with top/rear poly-Si contacts," 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC), Portland, OR, USA, 2016, pp. 2421-2424, https://doi.org/10.1109/PVSC.2016.7750076.

[2] J. Stuckelberger, et al., EUPVSEC (2020) Industrial Solar Cells Featuring Carrier Selective Front Contacts.

[3] B. Kafle, T. Freund, S. Werner, J. Schon, A. Lorenz, A. Wolf, L. Clochard, E. Duffy, P. Saint-Cast, M. Hofmann, J. Rentsch, „On the Nature of Emitter Diffusion and Screen-Printing Contact Formation on Nanostructured Silicon Surfaces,” IEEE J. Photovoltaics. 2017 7, 136, https://doi.org/10.1109/JPHOTOV.2016.2626921.

[4] Kafle, B., Mack, S., Teßmann, C., Bashardoust, S., Clochard, L., Duffy, E., Wolf, A., Hofmann, M. and Rentsch, J. (2022), Atmospheric Pressure Dry Etching of Polysilicon Layers for Highly Reverse Bias-Stable TOPCon Solar Cells. Sol. RRL, 6: 2100481. https://doi.org/10.1002/solr.202100481.