A reclaiming process for solar cell silicon wafer surfaces

Area of Science:

• Materials Science
• Semiconductor Manufacturing
• Surface Engineering

Background:

• Low yield in epoxy film and Si3N4 thin-film deposition impacts semiconductor production.
• Efficient removal of these layers is crucial for wafer quality and recycling.

Purpose of the Study:

• To present a new design system for precision reclaiming of Si3N4 layers and epoxy films from silicon wafers.
• To develop a mass production system for recycling defective solar cell wafers.

Main Methods:

• Utilizing a set of three lamination-shaped electrodes as a machining tool.
• Employing micro electro-removal as a precision reclaiming process.
• Investigating the impact of electrode dimensions (thickness, length, edge radius) and process parameters (electric power, feed rate) on removal rate.

Main Results:

• Smaller anode/cathode thickness, shorter length, and smaller edge radius correlate with higher thin-film removal rates.
• Sufficient electric power and higher wafer feed rates accelerate the electro-removal process.
• The developed technology offers a clean production approach for removing surface microstructure layers.

Conclusions:

• The new micro electro-removal system provides an efficient method for reclaiming Si3N4 and epoxy films from silicon wafers.
• This precise engineering technology facilitates a mass production system for recycling solar cell wafers, reducing pollution and costs.