Multilayer stack materials on silicon-based wafer dicing processes using ultraviolet laser direct dicing and milling methods

In this study, a laser power versus dicing speed models were developed to determine whether laser direct scribing or laser milling is more suitable for wafer dicing. The dicing depth of the two methods were examined. An 8-in. silicon wafer with a 0.75-mm-thick multilayer stack material was diced using a nanosecond pulsed ultraviolet laser system with a 355-nm laser wavelength. The wafer was subsequently broken by using a die separation platform. The processing parameters included a laser power of 5.1, 8.05, 8.95, and 9.58 W at a dicing speed of 50, 100, 300, 500, and 700 mm/s, all of which were examined alongside the contour at the dicing edge to evaluate the dicing quality. Moreover, field-emission scanning electron microscopy and three-dimensional confocal microscopy were used to analyze the properties of the diced materials, including surface morphology and dicing depth, as well as the chipping, microcrack, debris, and residual widths. The results revealed a relationship between the dicing quality and processing parameters that could serve as a reference for microcutting multilayer stack materials on silicon wafers in on-line production processes.