Process development for high scan speed ArF immersion lithography

Abstract

It has been found that 193nm immersion lithography technology can achieve smaller patterns without any modification to the technology infrastructure of existing state-of-the-art 193nm dry lithography. This has made 193nm immersion lithography a promising technology for mass production processes. Recently, scanning speed of the exposure stage has been increasing in order to achieve high throughput for mass production. At present, the adoption of a topcoat is one of the promising candidates for this high speed scanning process. On the other hand, the demand for a non-topcoat process is being pursued from a C.O.O. (cost of ownership) point of view but there are still issues being revealed and concerns to be solved. In this report, feasibility of a comprehensive process for high scanning ArF immersion lithography was discussed. As for the topcoat process, a high receding contact angle topcoat, such as TC-A (JSR), is proving to be a good candidate for mass production using high scanning speed immersion lithography. TC-A has a similar defectivity and lithographic performance to TCX041 (JSR). On the other hand, the feasibility of a non-topcoat process was also investigated. CD uniformity, defectivity and lithography performance of AIM5120JN and AIM5570JN (JSR) data indicate that the non-topcoat process can be adopted for mass production process. An immersion cluster comprised of a high volume production immersion exposure tool, S610C (NIKON) having 1.3 NA and CLEAN TRACK^TM LITHIUS^TM i+ (TEL) track system were used in this study.