Laser grooving on narrow scribe widths on thick flip chip wafer: The challenges and its resolution

LowK technology is continuously advancing and is a technology required for higher speed and performance for a semiconductor die. However, the high manufacturing cost of producing a LowK wafer needs to be addressed. One of the methods to lower this cost is to fit as many dies into a given wafer size, be it 6, 8, or 12 inch diameter. In order to perform this task, one of the method is to reduce the scribe widths (or street width) between the dies. These narrow scribes are an immediate challenge for a technology which requires Laser Grooving to etch off the sensitive LowK layer, in which the traditional mechanical dicing is unable to perform. The paper describes the technical challenges of dicing through narrower scribe widths on thicker flip chip wafers. It also describes the methods used to ensure that the laser grooving and mechanical placement drifts are properly addressed with the use of the Short Kerf Check (SKC) function which is jointly developed with the dicing manufacturer.