In our product information, we recommend developer AR 300-26 for the development of AR-P 5320, our positive photoresist for lift-off applications. A few users however prefer to work with MIF-developers. Since our strongest TMAH-developer AR 300-44 (0.24 n) turned out to be too weak for the structuring of AR-P 5320, dilutions of the MIF-remover AR 300-73 were evaluated. Good results were obtained with a 1:1 dilution of AR 300-73 (approx. 0.35 n). The sensitivity was about 290 mJ/cm2 with a very low dark erosion of less than 5 % after 10 minutes.