High scan speed EBL containing contact hole resists with low defectivity

In the previous paper we discussed the relationship between blob defect count and the receding angle of a resist surface after development with an alkaline developer solution. This paper summarizes additional test results from our continued efforts in developing next generation embedded barrier layer (EBL) materials that render a resist film with even higher receding angle to further facilitate high speed and high acceleration scanning. How to reach a higher receding angle without sacrificing a low post development receding angle is also discussed in this paper. The ability for an EBL material to switch from a high receding angle to a receding angle of lower than 20 degrees upon development is considered a very important attribute of an EBL, which is the key to reduce blob defect count by ensuring good dynamic wetting of a resist surface to DI water during a post development rinsing step. Resist formulations with different receding angles were studied for lithography performance and defectivity under different process conditions with varying wet processes. Both good lithography performance and low defectivity were obtained for contact hole resists including those with a surface receding angle of 78 degrees.