Plasma-Free Dry-Chemical Texturing Process for High-Efficiency Multicrystalline Silicon Solar Cells
The ADE (Atmospheric Dry Etching) technology provides a new way of carrying out dry gaseous etching without the limitations of other common vacuum plasma based technologies. The ADE process works at atmospheric pressure and does not require a plasma or the containment of a vacuum. It provides the solar cell manufacturing industry with a viable alternative to the long standing incumbent wet etching process, enabling the high throughput production of solar cells, now and into the future. ADE delivers superior etching rates and its specific cost of ownership is highly competitive for capacity production scenarios.
Several types of texture can be obtained using ADE, from nano-features (traditionally obtained with vacuum based RIE etchers reffered to as “black silicon”), to micro-size textures (similar to the wet etch). ADE is also compatible with any type of silicon wafer and does not require specific chemistries; one tool is suitable for all substrates (mono,multi, quasi-mono, diamond wire-cut or slurry cut), including low cost substrates and thin epitaxial layers. It provides an enabling solution for diamond wire cut mc-Si wafers. The mc-Si wafers cut using diamond-wire can not be textured with traditionnal wet chemistry. ADE provides an alternative dry solution, faster and cheaper than RIE. The etching chemistry does not produce any high global warming potential gases, and there is no water involved in the texturing process.