Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures Processing Measurement and Phenomena · 1995 · 380 citations · 0 references
EngineeringMaterials EngineeringMaterials ScienceMicrofabricationNanotechnologyPhotonicsMask FabricationMems FabricationMicrofabrication MaterialsMicrofabrication ProcessesMicromachiningSurface MicromachiningDeep Ultraviolet LithographyHigh-aspect-ratio MicromachiningHigh-aspect-ratio StructuresPhotoresist EtchingPhotoresistsReactive Ion EtchingSilicon EtchingSilicon Micromachining
This article describes a new negative-tone photoresist, SU-8, for ultrathick layer applications. An aspect ratio of 10:1 has been achieved using near-ultraviolet lithography in a 200-μm-thick layer. The use of this resist for building tall micromechanical structures by deep silicon reactive-ion etching and electroplating is demonstrated. Using SU-8 stencils, etched depths of ≳200 μm in Si and electroplated 130-μm-thick Au structures with near-vertical sidewalls have been achieved.