Polishing & Reclaim

After a silicon wafer has been used by a semiconductor fab, it can be re-polished/reclaimed and reused by the fab as a test wafer at a considerably lower cost than using a new test wafer. Silicon wafers can be repolished/reclaimed up to five times, depending on the silicon removal rate. It is recommended that fab technicians handle and package wafers carefully if they plan to reclaim them, to avoid unnecessarily scratching or contaminating the wafer surface. SVM is capable of polishing/reclaiming wafers ranging in diameters from 50mm to 300mm in either a single side polish (SSP) or double side polish (DSP) process. We utilize a number of different processes for wafer reclaim ranging from a simple “strip and clean” process, to a minimal “kiss” polish to a full repolish/reclaim of the wafer.

SVM’s wafer reclaim process starts with a wafer inspection, where wafers are sorted by thickness, type and resistivity. The wafers then move into either lapping or etching, depending upon the type of film or pattern on the wafer and the general condition of the wafer at incoming inspection. After etching or lapping, the wafers are generally free of surface defects and are ready for repolishing. Polishing can be either single side polish (SSP) or double side polish (DSP) depending on the wafer diameter and specification. After polishing, the wafers proceed into the cleaning process, and then through a final inspection process, including particle inspection (surface cleanliness). The wafers are then packaged in a clean cassette, double bagged, labeled and boxed for shipment.

One popular service we provide is taking in wafers with films on them, perform a simple strip & clean of the wafer, and then reapply a new film for the customer. We refer to this as a “strip and regrow” process.