A process and system scribe sapphire substrates, by performing the steps of mounting a sapphire substrate, carrying an array of integrated device die, on a stage such as a movable X-Y stage including a vacuum chuck; and directing UV pulses of laser energy directed at a surface of the sapphire substrate using a solid state laser and locating edges of the substrate. The cutting is stopped based on the edge location, to prevent impacting background elements. The pulses of laser energy have a wavelength below about 560 nanometers, and preferably between about 150 in 560 nanometers. In addition, energy density, spot size, and pulse duration are established at levels sufficient to induce ablation of sapphire.