Mask materials for powder blasting

Powder blasting, or abrasive jet machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle ma terials such as glass, silicon and ceramics. The particle jet (which expand s to about 1 cm in diameter) can be optimized for etching, while the mask d efines the small and complex structures. The quality of the mask influences the performance of powder blasting. In this study we tested and compared s everal mask types and added a new one: electroplated copper. The latter com bines a highly resistant mask material for powder blasting with the high-re solution capabilities of lithography, which makes it possible to obtain an accurate pattern transfer and small feature sizes (<50 mu m).