multiple photoresist patterning and development wet etching and or dry etching rie drie and other etch techniques can be used during different steps the multilevel structure may thereby be produced at commercially acceptable production rates allowing the method of the present application to be used in volume production of multilevel structures application_number US 20991802 A description advantages of the present invention will become more apparent from the detailed description given herein however it should be understood that the detailed description and specific examples while indicating preferred embodiments of the invention are given by way of illustration only since various changes and modification within the spirit and scope of the invention will become apparent to those skilled in the art form this detailed description fig2 a 2 f display a preferred embodiment of the invention for etching 3 level mems structures substrate 50 fig2 a e g silicon is coated with a photoresist which is patterned and developed 10 with the substrate 50 heated using intense uv light 100 and chemicals not shown the resist 10 is crosslinked 110 making it resistant to etching fig2 b the crosslinked photoresist 110 is of the order of thickness of 1 5 micrometers a second photoresist layer 120 is patterned and developed on the crosslinked photoresist 110 without affecting the crosslinked pattern the undeveloped photoresist is removed e g by a standard solvent fig2 c the substrate 50 is etched 130 fig2 d to a predetermined level then the remaining photoresist 120 is removed leaving.