Mass production of 193-nm immersion lithography has been started. Top coat process is one of the practical solutions for
applying the conventional dry ArF resists to achieve low material leaching and good scanning property, etc... At the
present, the lithographic world requires non-topcoat process from the point of view of C.O.O. (cost of ownership),
however there are still concerns that have to be revealed and solved. In order to achieve higher scan speed, the superior
water repellent property is required at the surface of non-topcoat resist. On the other hand, the influence of water
repellent surface property to the track process has to be considered. In this report, the considered items (coating,
development, etc...) of the higher water repellent property in non-topcoat process were extracted. Material design for
optimization of surface property with JSR non-topcoat resist and novel rinse method from process were proposed as
solutions to the concerns. Optimization of surface property showed positive impact to the development and defect
performance. The novel rinse method "ADR" which has been developed by Tokyo Electron showed superior availability
to reduction of blob type defect.
Residue type defect is one of yield detractors in lithography process. It is known that occurrence of the residue type
defect is dependent on resist development process and the defect is reduced by optimized rinsing condition. However, the
defect formation is affected by resist materials and substrate conditions. Therefore, it is necessary to optimize the
development process condition by each mask level. Those optimization steps require a large amount of time and effort.
The formation mechanism is investigated from viewpoint of both material and process. The defect formation is affected
by resist material types, substrate condition and development process condition (D.I.W. rinse step). Optimized resist
formulation and new rinse technology significantly reduce the residue type defect.
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<sup>TM</sup> LITHIUS<sup>TM</sup> i+ (TEL) track system were used in this study.