The dissolution behaviors of chemically amplified resists for electron beam lithography (EB CARs) have been investigated using the technique of quartz crystal microbalance (QCM) method. We report the first direct measurement of the dissolution rate of EB CARs and the comparison with CAR of using KrF exposure in wafer fabrication. The EB CAR for nano-imprint lithography mold making was also evaluated by this technique, and then resolved 50 nm line and space patterns using conventional 50 KV variable shape beam writing system. The understanding of dissolution kinetics of EB CARs is capable of designing high performance resists in near future.
We have developed PCARs for LEEPL mask making that has high resolution, good CD uniformity and process stability. The proper choice of resists and the process optimization enabled to form 60nm hole patterns and achieved the local CDU<4.0nm at 80nm hole patterns using the current 50 keV VSB exposure system. The results of the examination about PEB temperature and CD revealed that the CD of small hole patterns was controlled by the quencher diffusion rather than the generated acid diffusion. Defocus issue was also investigated and the sensitivity control of a resist was effectively method against CD error. These results in this report clearly indicate the strategy of the resist development for resolve less than 100nm feature size using EB exposure system.
We investigated the film property and the lithographic performance of five commercialized NCARs. This report focused on Cr effect and PCD stability which are critical issues on advanced mask making. Results confirmed to solve the Cr effect by controlled dissolution rate of resist film. Furthermore, PCD was occurred by PAG moving and unsuitable reaction in the resist film standing delay time. This report suggests the strategy that was design of chemical structure for the next generation NCARs.
We investigated the film property and the lithographic performance of five commercialized NCARs. This report shows the relationship between chemical structure and EB lithographic performance, such as resolution, sensitivity and environmental stability. In this study, we found the good matching the matrix polymer, the cross linker and the photo acid generator(PAG) against NCARs issues. Furthermore, we could demonstrate the trade-off relation for lithographic factor and stabilized factor by chemical characteristics. This report suggests the strategy that was design of chemical structure for the next generation NCARs.