EUV imaging performance: moving towards production

ASML's two alpha demo tools (ADTs) have successfully gone through acceptance testing at the customer sites. The ADTs are full field step-and-scan exposure systems for extreme ultraviolet lithography (EUVL) and are being used for EUVL process development. The main objectives for the program are to prepare EUVL for insertion at the 27nm node, and to support the development of the global infrastructure of masks and resist. Resolution of 28nm dense L/S has been demonstrated recently. In this paper we will look at the imaging performance of the AD-tools in comparison to the requirements for the 32nm node for Memory (NAND-Flash and DRAM) and 22nm node Logic applications, as these feature sizes can be supported by the current resist performance. Process windows and MEEF are evaluated for L/S and CHs through pitch down to 32nm half pitch. Furthermore, the full wafer CD uniformity of the critical features of a NAND-Flash gate layer at 32nm half pitch is presented as well. Based on these findings the expected imaging performance of the TWINSCAN NXE:3100 at the 27nm node will be discussed.