Elimination of post-release adhesion in microstructures using thin conformal fluorocarbon films

The adhesion of polysilicon microstructures to their substrates is eliminated using a thin coating of a hydrophobic fluorocarbon film. The film is grown in a plasma reactor in a field-free zone yielding a relatively conformal film growth. Experiments confirm the presence of the film on the surfaces of 100 μm undercuts with contact angles of 110°. The film eliminates the adhesion of polysilicon beams up to 230 μm-long even after direct immersion in water. Initial accelerated aging tests indicate that the film withstands temperatures up to 400°C. Wear test show the film remains effective after 10⁸ contact cycles