Photoresist removal from a substrate

Patent Pending After a photoresist is no longer needed, it must be removed from the substrate. This usually requires a liquid "resist stripper", which chemically alters the resist so that it no longer adheres to the substrate. Alternatively, photoresist may be removed by a plasma containing oxygen, which oxidizes it. This process is called ashing, and resembles dry etching. 1-Methyl-2-pyrrolidon (NMP) solvent is another method used to remove an image.