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Wafer Thinning and Strength Enhancement to Meet Emerging Packaging Requirements
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IEMT Europe 2000 Symposium (IEEE/CPMT), Semicon Europa, April 2000, Munich, Germany
Authors: Ernst Gaulhofer, Heinz Oyrer
Abstract:
Thin wafers or dies with a thickness down to 100 microns are nowadays virtually a standard requirement for smartcard applications. For a long time now, the most common thickness of about 180 microns has increasingly been replaced by thinner successors. Consequently, today there is already a market requirement for "super thin" dies. In Japan, for example, there are strong efforts to standardize a new generation of contactless smartcards with a final thickness of only 250 microns. It is therefore clear that these cards, with only a third of the current thickness, require extremely thin dies. Based on these developments it can be seen that the average thickness of a thin wafer is being halved every two years. So we can expect a thickness of about 50 microns by 2002 at the latest. There are several technology approaches to thin wafers after grinding on the market, i.e. CMP-type, Plasma and Wet solutions. The first two still induce some mechanical damage to the substrate surface, the latter does not and can result in a wide range of backside surface properties ranging from mirror-like polished surface to semi-rough and rough ones. This single-wafer wet process approach will be presented as the Spin-Etch solution to overcome problems associated with other systems ....
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