Wafer dicing using femtosecond-based laser and plasma etch

Methods of dicing semiconductor wafers, each wafer having a plurality of integrated circuits, are described. A method includes forming a mask above the semiconductor wafer, the mask including a layer covering and protecting the integrated circuits. The mask and a portion of the semiconductor wafer are patterned with a laser scribing process to provide a patterned mask and to form trenches partially into but not through the semiconductor wafer between the integrated circuits. Each of the trenches has a width. The semiconductor wafer is plasma etched through the trenches to form corresponding trench extensions and to singulate the integrated circuits. Each of the corresponding trench extensions has the width.