Multicrystalline Wafers
Application: Remove damage created in the sawing process, texturize the wafer surface and prepare the wafers for diffusion.
The process uses base solution for particle removal and acids for controlled etching and texturization and for ionic contamination removal.
Process
Purpose
Pre-clean
(recommended)
(recommended)
Use an alkaline pre-treatment solution to remove organic contamination and particles
from the wafer surface to improve texturization uniformity.
HF/HNO3
Acidic solution eliminates damage (small cracks) from sawing process that if not
eliminated would reduce the amount of energy that is outputted from the cell.
Create small bumps on the wafer to reduce the amount of light that is reflected off of the wafer surface.
Create small bumps on the wafer to reduce the amount of light that is reflected off of the wafer surface.
KOH
Alkaline solution removes the porous silicon generated from the above acidic texturization step.
HF/HCl
Final clean step removes metal impurities and oxide to maximize minority carrier
lifetime and sheet resistance to yield higher cell efficiency.
Saw Damage
Removal/Texturization
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Removal/Texturization
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Top View Drawing
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For further information or to set up a teleconference with a NAURA Akrion process expert, please send an email request to marcom@akrionsystems.com