Solar Energy Materials and Solar Cells, Vol.72, No.1-4, 277-284, 2002
Dry processing of silicon solar cells in a large area microwave plasma reactor
We report a dry Si solar cell process that replaces all wet chemistry by various microwaveexcited plasma treatments. The key steps are: (i) SF6 plasma etching to clean the wafer prior to the emitter diffusion, (ii) CHF3 plasma etching to remove the phosphor silicate glass (PSG) after diffusion, (iii) SF6 plasma treatment for mesa etching of the emitter, and (iv) the plasma deposition of an antireflection coating. We also avoid wet chemistry during the metallization, The best completely dry-processed float-zone Si cell shows a power conversion efficiency of 14.7%. The wet-processed reference has an efficiency of 15.1%. (C) 2002 Elsevier Science B.V. All rights reserved.
Keywords:dry solar cell process;plasma etching