Resist AR-P 5900/4 is already well established on the market for many years. Structures of this positive resist are characterized by a considerably higher alkaline stability as compared to standard positive resists (e.g. AR-P 3510 or AZ resists). Used in most cases as protective coating for alkaline baths, a tempered layer is able to withstand 2 n NaOH solutions for a few minutes. If this film however is to be structured, very long exposure times and a well agitated developer bath are required to completely develop exposed areas.
For these reasons, resist SX AR-P 5900/8 was designed. Acid generators and cross-linking agents were added to this positive resist. After a soft bake at 95 °C, the resist can be structured as usual and with good sensitivity. If these structures are now tempered again at temperatures between 120 – 150 °C, the stability against alkaline solutions increases substantially. Resist structures are now able to remain more or less undamaged for up to 30 minutes (150 °C) in 2 n NaOH solutions.
If SX AR-P 5900/8 is used as protective coating, the tempering after coating has to be carried out in a range between 120 – 150 °C. Films treated in this manner can be removed with standard removers.