Can Silicon Wafers Be Recycled?  


August 8, 2022

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While thousands of wafers are manufactured annually, it's no surprise that this material can produce a significantly high volume of waste. Thin silicon wafers have proven to be a problem since recycling this material takes a lot of work and sophisticated understanding. Fortunately, numerous strategies are being tested to help decrease the volume of waste being produced.  

inspecting thin silicon wafers 

A Method to Recycle Silicon Wafers  

Silicon Recycling Processes  

Waste from silicon wafers is gathered and examined using scanning electron microscopy, X-ray diffraction (XRD), and particle morphology (SEM). The silicon sludge is then grounded into tiny particles and subjected to a high-temperature SHS reaction to create a ceramic material called SiAlON.    

Due to low nitrogen pressure, the XRD data unequivocally demonstrates that only 50% of the silicon sludge can be transformed into SiAlON. After that, the SiAlON powder was combined with 25% weight percent of Y2O3-stabilized ZrO2, formed into pellets, and sintered at 1,600°C to 92% of the theoretical density. The highest Vickers hardness of these materials was just 4.6 GPa, which is significantly less than the predicted range of 12–15 GPa.  

The Outcome of the Process  

This experiment proved that silicon wafer production wastes might be turned into SiAlON ceramics via a high-temperature SHS reaction. However, it was discovered that a higher nitrogen operating pressure than the current SHS reactor system is needed to convert silicon sludge into SiAlON ultimately. Other prospective ceramic material developments, such as TiN from Ti or AlN from waste Al, were also investigated in the SHS autoclave.  

Alternative Solution  

Scientists from the Key Laboratory of Urban Pollutant Conversion may have developed an alternative that entirely skips the energy-intensive ingot manufacture stage. According to the group's research, skipping the steps of producing silicon ingots and cutting wafers can reduce the cost of producing PV modules by about 40%. Some experts have previously suggested that the best course of action is shifting this silicon to uses with lower purity requirements.  

a worker handling thin silicon wafers 

Are You Interested in Learning More About Thin Silicon Wafers?  

Silicon wafers are an industry standard when it comes to advanced electronics. Here at Wafer World, our team manufactures wafers with superior quality. Give us a call today to learn more about our services.

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