What is Wafer Recycling? Wafer recycling is an etch process which will remove most semiconductor thin films if performed correctly. This recycling process will not alter the flatness or thickness of the wafer, which is a major benefit of recycling as opposed to reclaim. Wafer recycling is not a polishing process. Noel will sort wafers that are scratched, hazed or badly damaged. Customers can then choose to have those wafers reclaimed.
What is Wafer Reclaim? Reclaimed wafers are used prime and test wafers which have been stripped of thin films and then re-polished to remove all patterns and scratches. After receiving wafers which fall short of Noel spec for recycling due to silicon haze or scratches, they are sorted for thickness and resistivity. Following the reclaim process, the wafers will perform as well as a normal test wafer. Reclaimed wafers may be slightly thinner than most virgin wafers; however, Noel will reject any wafers which could be problematic for the customer.
What is a Prime Wafer? Prime wafers are considered to be device quality wafers with extremely tight specifications for resistivity, flatness and particle count. Due to their tight uniformity, Noel recommends prime wafers Lithography Requirements as well as particle monitors and CMP qualifications.
What is a Test Wafer? Most test wafers are wafers which have fallen out of prime specifications. Test wafers may be used to run marathons, test equipment and for high end R & D. They are often a cost effective alternative to prime wafers.
What is the difference between Noel’s Reduced Particle Clean (RPC) process and the Spin Rinse Dry (SRD) clean? Noel’s Reduced Particle Clean (RPC) is a proprietary scrub process which loosens contaminants and particles, resulting in an ultra low particle clean. The tool is a single wafer cleaning scrub, as opposed to Spin Rinse Dry (SRD) clean, which is accomplished in a SRD rinser dryer in batch loads. Noel’s RPC process will result in double digit particle counts on 300mm wafers and single digit counts on smaller substrates.