Nd:YAG laser-induced damage on ultrathin silicon samples

The single shot laser induced damage onset and morphology of ultrathin silicon wafers is investigated using a Q-switched, single longitudinal and transverse mode Nd:YAG laser operating at 1.06 micrometers . The wafers had a thickness of 2.5 - 33 micrometers with identical front and back surface polish and <100> orientation. Comparisons are made for simultaneous front and back surface damage at the lowest level detectable surface modification. The morphology of laser damage on front and back surface due to the application of multiple shots on one site (N/1) at higher fluence values was also monitored. A scatter probe system consisting of a laser beam analyzer and a CCD array was used. It allowed the in-situ observation of the development of damage on the samples.