Utilizing the transparency of silicon at 2 μm, we are able to ablate the backside of 500-μm thick
silicon wafers without causing any damage to the front surface using a novel nanosecond
Tm:fiber laser system. We report on our high energy/high peak power nanosecond Tm:fiber
laser and provide an initial description of the effects of laser parameters such as pulse duration
and energy density on the ablation, and compare thresholds for front and backside machining.
The ability to selectively machine the backside of silicon wafers without disturbing the front
surface may lead to new processing techniques for advanced manufacturing in solar cell and