Hello, I have not tried the method that you suggest. However, the vendor of the S1813 photoresist (I believe it is Microchem?) does also sell a developer which they claim will not attack aluminum. If you cannot get the single S1813 resist film to work, you could try calling Microchem and asking one of there technical support people about it. Good Luck, Bill -----Original Message----- From: ahajjiah Subject: [mems-talk] Problems with lift-off using S1813 photoresist Dear All, I am having a lot of problems using S1813 photoresist for my lift-off. It was recommended to me in the past to use S1813 with LOR3A or LOR5A to help me solve my lift-off problem. unfortunately, by using the bi-layer photoresist system my lift off problem was solved but the developer, the AZ400K developer, i used to do the lift off was etching my Al metal.