Figure 1

Process flow for submicron fabrication on Parylene C: (a) Parylene C layer 10 μm thick is deposited on a silicon carrier through chemical vapor deposition; (b) larger structures, such as electrodes or contact pads, are fabricated with UV lithography, metal vaporization, and liftoff; (c) a PMMA resist bilayer 570 nm thick is prepared with spin-coating and baked at 120 °C for 20 min; (d) a chromium conducting layer is deposited—15 nm thick, and the pattern is exposed with electron beam lithography; (e) the chromium layer is removed and the resist developed; (f) the submicron pattern is metalized in 150 nm of titanium using metal evaporation and liftoff; (g) a second Parylene C layer of 10 μm thick is deposited; (h) Parylene insulation above contact pads is etched with deep reactive ion etching; (i) the completed device is removed from the silicon carrier. Parylene C, poly(chloro-p-xylylene); PMMA, poly(methyl methacrylate); UV, ultraviolet.