US Patent 8143686 - Laser-induced nanostructures

http://www.freepatentsonline.com/8143686.html

Pulsed laser etching can be useful in shaping microstructures but is typically not feasible to create structures smaller than the laser wavelength. This patent from Harvard teaches a 2-step laser pulsing method which allows for nanoscale structures to be formed on micron structures. Claim 1 reads:

1. A semiconductor substrate, comprising a plurality of micron-sized structures disposed in a top surface layer of the substrate, and a plurality of rod-like nano-sized structures superimposed on said micron-sized structures.