Silicon dioxide thin film removal using high-power nanosecond lasers

High intensity nanosecond laser pulses of different wavelengths are used to remove thin film silicon dioxide coatings from the silicon surface. Films as thick as 0.7 μm can be removed from the surface in one shot with very minor or no damage to the bare silicon surface. The accumulated effect of multiple-pulse irradiation is studied. It is found that multiple-pulse irradiation results in some reduction of the threshold for coating removal. However, the surface quality gets significantly worse with the increasing number of shots.