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[摘要]：Submicron wafer-to-wafer alignment is critical in wafer bonding for the fabrication of three-dimensional integrated circuits. In this work, the authors examine the sources of misalignment in traditional alignment methods and then examine the capabilities of an alternative alignment approach that uses capillary forces. A multiscale model was developed to investigate the potential of capillary assisted alignment. The model consists of a local model of a confined liquid droplet and a finite element model that predicts wafer-level distortions and misalignment. Using the model, the effect of pattern error and wafer nonflatness on misalignment in bonding was examined for both the traditional and capillary assisted methods. The results indicate that capillary assisted alignment has several distinct advantages over traditional methods that result primarily from the ability to align the wafers at many locations across the wafer. (c) 2007 American Vacuum Society. |
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