SU-8 2002 is best suited for permanent applications where it is imaged, cured and left on the device.
 It may also be exposed with e-beam or x-ray radiation.  

Upon exposure, crosslinking proceeds in two steps

 (1) formation of a strong acid during the exposure step, followed by 

(2) acid-catalyzed, thermally driven epoxy cross-linking during the post exposure bake (PEB) step.  A normal process is:  spin coat, soft bake, expose, PEB, followed by develop.  Substrate Preparation To obtain maximum process reliability, substrates should be clean and dry prior to applying SU-8 2002 resist. For best results, substrates should be cleaned with a piranha wet etch (using H2SO4 & H2O2) followed by a de-ionized water rinse.  Substrates may also be cleaned using reactive ion etching (RIE) or any barrel asher supplied with O2.  Adhesion promoters are typically not required. For applications that require electroplating it is recommended to pre-treat the substrate with MCC Primer 80/20 (HMDS). 
Features •Improved adhesion •Reduced coating stress •High aspect ratio imaging •Vertical sidewalls •Greater than 100 µm film thickness in a single coat •Excellent dry etch resistance