Powder blasting patterning technology for microfabrication of complex suspended structures in glass

We present a powder blasting microfabrication method and realize with it complex three-dimensional and monolithic suspended microstructures in glass. We also compare the usual metal contact mask to an alternative photosensitive flexopolymer. At normal incidence of the powder beam, the obtained profiles are similar for both methods and both the metal contact mask and the flexopolymer erosion selectivity with respect to glass is ∼ 50. By controlling the underetching induced by oblique powder blasting, suspended structures are realized, using a metal contact mask directly into the substrate. These structures can be realized in a single oblique erosion step or by a two-step normal/oblique erosion process.