A method for effecting anisotropic etching of a layer of a material without producing dimensional loss even if the photoresist is of a reverse tapered cross-sectional profile is proposed. A photoresist produced from a chemical amplification negative type photoresist tends to be of a reversely tapered...http://www.google.fr/patents/US5342481?utm_source=gb-gplus-shareBrevet US5342481 - Dry etching method
