High speed, laser-based marking method and system for producing machine readable marks on workpieces and semiconductor devices with reduced subsurface damage produced thereby

A method of laser marking a semiconductor wafer during at least one step of a semiconductor manufacturing process, the wafer having a first side with circuit features, and a second side having a rough wafer surface portion to be marked, the method comprising:

• generating a q-switched laser output for wafer marking, the output comprising an output wavelength less than an absorption edge of the semiconductor wafer material, a laser output power of at least about 3W at the wavelength, a plurality of pulses, each pulse having a pulse width less than about 50 ns, at least one pulse having a pulse width in the range of about 10–15 ns, the temporal spacing between at least some consecutive pulses of the plurality of pulses corresponding to a repetition rate of at least 15 Khz;
• and
• irradiating the semiconductor wafer with the output over at least one spot having a diameter in the range of less than about 60 microns to produce a shallow mark having sufficient contrast for machine readability, whereby the at least one pulse irradiates at least about 108 W/cm2 over the diameter while avoiding undesirable subsurface damage to the semiconductor wafer.