A new electroplating mask for deep wet etching on glass

In this paper, a new electroplating mask regarding deep etching on glass was revealed. It consisted of sputtered Chromium and Copper layer with electroplated Chromium and Gold layer, in combination with hard baked thick photoresist AZ4620 mask layer. After more than 3 hours' immerging in the HF etching solution, the etching depth attained more than 500μm. By using hard baking photoresist, the smoother surface was achieved. In addition, increasing the pattern width may help to reduce the undercut etching level and to accelerate the etching process. Compared with other masks in the literature, this new electroplating mask was simple, low cost and compatible with lithography technology, it can be widely used in MEMS applications.