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

According to sizes dictated by ITRS road map, contact holes are one of the most challenging features to be printed in the semiconductor manufacturing process. The development of 90[nm] technology 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 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 simple to be manufactured, with a modified illumination and single exposure, with no impact on throughput and without any 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.