Hi, well I want to get the Al-layer in electrical contact to another metallic layer. The oxidation barrier should avoid contact problems because of an isolating oxide. Best regards, Chris -----Ursprüngliche Nachricht----- Von: mems-talk-bounces+engel.christian=gmx.de@memsnet.org [mailto:mems-talk-bounces+engel.christian=gmx.de@memsnet.org] Im Auftrag von Pramod Gupta Gesendet: Dienstag, 15. März 2011 23:22 An: General MEMS discussion Betreff: Re: [mems-talk] PVD of thick Al-Layer 1. You can use KOH or NaOH solution for wet chemical etching of Al. Even the AZ series photoresist developers work well for etching of Al because they are also KOH based solution. 2. Why do you want to use oxidation barrier? If you want to pattern the thick Al film, you can use photoresist directly on Al film without any oxidation barrier like Au. For etching the Al film in PR developer or KOH, you have to hard bake the PR at higher temp. Let me know if you have any questions. Thanks. Pramod Gupta