A process is described for manufacturing submicron, ultra-high aspect ratio microstructures using a trench-filling etch masking technique. Deep trenches are etched into a substrate, the trenches are filled with an appropriate trench-filling material, and deep etching into the substrate ...http://www.google.fr/patents/US5770465?utm_source=gb-gplus-shareBrevet US5770465 - Trench-filling etch-masking microfabrication technique
