Patent ID: 6887396
Filing Date: 2005-05-03
Classification: B81B,B81C,G02B,Y10S

Abstract:
1. A method of making a micromirror unit, the unit comprising a frame, a mirror forming base, and bridges connecting the frame to the mirror forming base, the bridges including torsion bars, the method comprising the steps of: forming a first mask pattern on a substrate for masking portions of the substrate which are processed into the frame and the mirror forming base; forming a second mask pattern on the substrate for masking portions of the substrate which are processed into the bridges, the second mask pattern differing in material and anti-etching properties from the first mask pattern; subjecting the substrate to a first etching process with the first and the second mask patterns present as masking means; removing the second mask pattern selectively by using an enchant which etches away only the second mask pattern but not the first mask pattern; subjecting the substrate to a second etching process with the first mask pattern present as masking means; and removing the first mask pattern.