Evaluation of IDEALSmile for 90nm FLASH memory contact holes imaging with ArF scanner

摘要

According to sizes dictated by URS roadmap, contact holes are one of the most challenging features to be printed hi the semiconductor manufacturing process. The development of 90 [nm] technology NOR FLASH memories requires a robust solution for printing contact holes down to 100[nm] on 200[nm] pitch. The delay of NGL development, as well as open issues related to 157[nm] scanner introduction, pushes the industry to find a solution for printing such tight features using existing ArF scanner. IDEALSmile (Innovative Double Effective source Aided Lithography with Single Mask Implemented Lithographic Enhancement) technology from Canon was proven to be a good candidate for achieving such high resolution with sufficiently large through pitch process window using a binary mask, relatively cheap and simple to be manufactured, modified illumination, single exposure, without any negative impact on throughput and no increase of cost of ownership. This paper analyses main issues related to the introduction of this new resolution enhancement technology on a real FLASH memory device, highlighting advantages as well as known problems still under investigation.