3D-structuring of photosensitive glasses

Up to now it is possible to etch through the whole wafer or in a defined depth, but not with the same etching process. Structures with a defined depth had to be produced with a second UV-exposure followed by a second etching process. A new technology allows a 3D etching process in photosensitive glass. A lot of lines with a defined width and pattern are made in a chromium layer on vitreous silica. A pattern of different grey scales can be produced with that technology. The grey scale mask results in different intensities of W-light during the exposure. Due to the different intensities, the exposure of different areas is in various depths. The advantage of this technology is that structures not only with a defined depth but also with a defined design can be produced