Parylene etching techniques for microfluidics and bioMEMS

Parylene C (poly(monochloro-p-xylylene)) is a member of a unique family of thermoplastic, crystalline polymers. Compared to other polymers, parylene films are exceptionally conformal and chemically inert owing to its vapor deposition polymerization (VDP) coating process. These properties bring about many interesting possibilities for MEMS, particularly in microfluidic and bioMEMS applications. Dry etching techniques are required to define fine features in parylene films. For the first time, selective parylene C removal using oxygen-based plasmas is characterized for plasma etching, reactive ion etching (RIE), and deep reactive ion etching (DRIE) based methods. The ability of these techniques to achieve high aspect ratio (HAR) structures desirable for MEMS applications is also investigated.