12. What is the application range of protective coatings?

Protective coatings are available for a large variety of applications, e.g. for the protection of waferbacksides:

• for mechanical protection during transport
• as insulating layer
• for KOH- and HF-etchings (AR-PC 503, AR-PC 504 (both adhesion enlarged), SX AR-PC 5000/40)
• as temperature-stable intermediate layer for two layer procedures (SX AR-PC 5000/80).

Protective coatings are generally applied by spin coating. Protective coatings AR-PC 504, X AR-PC 5000/19, and 5000/30 contain polymethacrylate and tend to show the so-called “candy-floss“-effect at suboptimal rotational speeds. This effect can be reduced with a lower rotational speed, local exhaustion, and the removal of the “candy floss” with a glass rod during spin coating. Recommended are coatings at 1000 rpm.