I have an image-reversal bilayer recipe, using LOR10-A and AZ5214E, appropriate for 1.5 micron thick metal lift-off, but it's not quite finalized. Would you be able to inform this thread of readers to others? In my case, I don't want to change photomasks, so I much prefer AZ5214E on the top layer in an image- reversal mode. -----Original Message----- From: mems-talk-bounces+wilsont=marshall.edu@memsnet.org [mailto:mems-talk- bounces+wilsont=marshall.edu@memsnet.org] On Behalf Of Andrew Sarangan Sent: Monday, February 28, 2011 3:02 PM To: General MEMS discussion Subject: Re: [mems-talk] why no lift-off for Si processing To add what has been said already, many etchants are developed with silicon in mind. Some may attack III-V semiconductors, or react to produce undesirable byproducts on the surface (I've had the misfortune of losing an InSb wafer due to a Cr etchant). If you can blanket coat and then pattern down, adhesion, step coverage and substrate cleanliness will be better. You can also heat the substrate, which you can't if you have resist on it. If chemical selectivity does not allow for an etch process, then lift-off is the only option. However, lift-off is not all bad either. It can work very well, even with sputter deposition, by using a bilayer resist process.