Texturing is an important step in the manufacturing of a Silicon solar cell. This process removes the surface damage induced by wafer sawing. It also serves to reduce the reflectance of the wafers, and incorporate light trapping in the cell, by the creation of small bumps on the surface, thus increasing cell efficiency.
Typical chemistries include KOH, KOH/IPA, NAOH, HF/HNO3 per the wafer type:
- Polycrystalline Si - HF/HNO3 process
Concentrations need to be maintained in order to get a steady etch rate and the required texture. It is also meaningful to measure the silicate residue content, as that affects the etch rate as well.
Texturing Real-time Monitoring Equipment
The WetSpec201 and WetSpec200 provide an important tool for real-time monitoring of this key process by measuring not only the basic chemical components but also the Si by-product amount!