With the introduction of the NXE:3100 NA=0.25 exposure system a big step has been made to get EUV
lithography ready for High Volume Manufacturing. Over the last year, 6 exposure systems have been
shipped to various customers around the world, active in Logic, DRAM, MPU and Flash memory, covering
all major segments in the semi-conductor industry. The integration and qualification of these systems have
provided a great learning, identifying the benefits of EUV over ArF immersion and the critical parameters
of the exposure tool and how to operate it.
In this paper we will focus specifically on the imaging performance of the NXE:3100 EUV scanner.
Having been operational for more than a year a wide range of features were evaluated for lithographic
performance across the field and across wafer. CD results of 32nm contact holes, 27nm isolated and dense
lines, 27nm two-bar, 22nm dense L/S with Dipole, as well as several device features will be discussed and
benchmarked against the current ArF immersion performance. A budget verification will be presented
showing CD and contrast budgets for a selection of lithographic features. The contribution of the resist
process and the mask will be discussed as well.
The litho performance optimization will be highlighted with the 27nm twobar and isolated lines features
that are sensitive to the illuminator pupil shape and projection lens aberrations.
We will estimate the amount of resist induced contrast loss for 27 and 22nm L/S based on measurements of
Exposure Latitude and the contributors from the exposure system.
We will further present on the impact of variations in the mask blank and patterned mask on imaging, with
several new contributors to take into account compared to traditional transmission masks.
Finally, the combined results will be projected to the NXE:3300 NA=0.33 exposure system to give an
outlook for its imaging performance capabilities.