New deep glass etching technology

Abstract

A new masking technology useful for wet etching of glass, to a depth of more than 300µm, is reported; multilayers of metal in combination with thick SPRT220 photoresist, are used. This new method was successfully developed for fabricating a 200µm thick diaphragm for a micro peristaltic pump. Various mask materials, which can be patterned by standard photolithography and metal etching processes, were investigated. The main advantage of this newly developed method was the application of hydrofluoric acid etching to create deep cavities with a uniform membrane without pinholes, and to minimize lateral undercutting of the glass