Hydrophobic or hydrophilic? SELF ASSEMBLING MONOLAYERS SAM Surface stiction is a major problem during fabrication of MEMS components, such as silicon sensors, microactuators or microfludic devices. In addition, the same phenomena are a limiting factor for reliability and lifetime of these components on the customer’s side. The gas-phase SAM (self-assembling monolayers) coating process for micro components reduces or eliminates adhesion related phenomena. Essential for the industrial use of hydrophobic SAM-based coatings is the existence of a process suitable to be integrated in an industrial environment for fabrication of large volumes (serial production). microfab has developed such a process and offers it for surface modification.. BENEFITS OF SAM COATING - Avoidance of sticking....during use of MEMS devices with delicate structures, like suspended membranes, movable comb structures or cantilevers - Avoidance of sticking.. during wet processing of wafers with suspended MEMS structures - Generation of a hydrophobic surface....displaying low surface energy and high contact angles > 110°, similar to Teflon - Stabilization of the treated MEMS surface....by low-temperature steps (full back-end process compatibility) - Excellent mechanical and thermal stability Up to 400°C, therefore compatible to standard-packaging-processes including solder reflow - Selective coating of hydrophilic surfaces....with OH-bonds only (metal pads are not coated) - Low-cost batch process Serial production compatible high-throughput.
