Patent ID: 7705268

Claim:
A laser-marking method of marking a semiconductor wafer to form a softmark on the wafer, the method comprising: setting a laser pulse width of one or more laser pulses to selectively provide one or more laser output pulses having one or more set pulse widths that affect the depth of a softmark that is to be formed, the mark depth to be substantially dependent on the one or more set pulse widths; setting a pulse energy of the one or more output pulses to selectively provide the one or more output pulses having a set total output energy that is within an acceptable process energy window for producing the softmark; delivering the one or more output pulses having the one or more set pulse widths and the set total output energy into a region of the wafer such that energy density within the region, as determined by the one or more set pulse widths and the set total output energy, modifies wafer material and thereby produces the softmark having a raised annular rim and a recessed center with the mark depth within a predetermined range wherein the softmark is debris free; and controllably resetting the laser pulse width without substantially changing the energy density to change the mark depth within the predetermined range wherein the mark depth is controllably adjusted and wherein the mark depth is substantially proportional to a pulse width over a substantial range of pulse widths; wherein energy in a single output pulse is in a range of about 600 microjoules to about 1100 microjoules; and wherein the acceptable process energy window is centered on a central energy in a range having a lower limit of about 10 microjoules less than the central energy and an upper limit about 10 microjoules above the central energy and wherein diameter of the softmark is about 48 microns or greater.