CD performance of CA-resists with a dynamically controlled multi-zone bake system

Abstract. CD-uniformity data of chemically amplified (CA) resists have been generated, by using a dynamically controlled multi-zone hotplate system, APB5000. The optimized baking procedure of the APB5000 system for Post Coat Bake (PCB) and Post Exposure Bake (PEB) is characterized by a maximum in the total temperature range on a 6025 mask substrate surface of 0.5°C during the heat-up ramping and smaller than 0.2°C at the set-point temperature of 90°C. In this experiment CD-uniformity for isolated lines was improved to 7.8nm, compared to 13nm when using conventional baking systems. Additionally, a compensation method based on the baking processes is presented to further decrease the CD-uniformity range of CA-resists. Derived from CD-uniformity data measurements, a local temperature variation from the optimized baking strategy of the APB5000 system is used to compensate CD-errors caused by other process steps. In this experiment the result of such a measure showed a 40% improvement of the CD-uniformity range for dense lines from 14.2nm to 8.0nm.