The impact of airborne molecular bases on DUV photoresists

Exhaustive examination of resist characteristics for well-known parameters such as isolated and dense feature resolution, adhesion, and etch selectivi ty is ongoing. Sensitivity of resists to airborne molecular bases adds yet another parameter to be characterized. in an effort to bring the latest-gen eration processes into production more quickly, many device manufacturers h ave implemented several levels of safeguards to protect resists from bases such as ammonia, NMP, and TMA. This article compares the sensitivities of f our commercially available DUV resists to a number of airborne molecular ba ses.