A novel design of handling system for silicon wafer thinning

TSV fabrication consists of five major processes: via formation, via filling, wafer thinning, wafer handling, and die/wafer bonding [1-2]. Wafer thinning is one of key TSV processes which contributes more than 20% of TSV manufacturing cost and should be studied in a systematic manner. In wafer thinning process, especially for ultra-thin wafers, a reliable handling system is indispensable. The best known solution for thin wafer handling system is based on perforated carrier wafers, which are bonded by an adhesive to the customer wafer and de-bonded by solvent release of the adhesive [3]. The internal structure of the carrier wafer is important, which can affect several crucial parameters of the customer wafer after thinning process, such as wafer warpage and flatness. etc. Therefore, a feasible and satisfactory design for thin wafer handling is strongly demanded. In this paper, a low cost and reliable carrier system is presented. In our system, a novel room temperature debonding process can be achieved, and a carrier wafer with specific internal structure was designed.