Lithographic performance of a dual-stage 0.93NA ArF step and scan system

Abstract

This paper presents lithographic performance results obtained from the newest member of ASML's TWINSCAN TM platform-based step & scan systems, the TWINSCAN TM XT:1400. The system has been designed to meet the semiconductor industry's aggressive requirements on CD control, overlay and productivity at and below the 65 nm node. This dual stage 193 nm lithographic system combines the worlds highest NA, with excellent overlay and CD control at high throughput on both 200 and 300 mm wafers and is intended for use in volume production environments. Advances in stage technology have enabled further extension of stage scan speeds and an associated increase in tool productivity. However, maximizing the number of yielding die per day also requires stringent overlay and Critical Dimension (CD) control. Tight CD control at improved resolution is supported by the Starlith TM 1400 projection lens and the extended sigma capabilities of the new AERIAL TM -E illumination system. Focus control is improved in line with the stringent requirements posed by low-k 1 imaging applications, taking full advantage of the unique dual-stage TWINSCAN TM system architecture.

Optical wafer metrology sensors for process-robust CD and overlay control in semiconductor device manufacturing

“…In order to further drive down any residual focus error, lithography tools are optionally equipped with an additional non-optical sensor that is based on measuring airflow between a nozzle and the wafer surface [11]. Height variations between the wafer surface and the nozzle will change the airflow and these changes are detected with a small built-in flow sensor.…”

Impact of polarized illumination on high NA imaging in ArF immersion lithography at 45 nm node

“…The process factor k1 has been reduced to 0.3 and even smaller by several resolution enhancement technologies (RETs) such as modified illumination, phase shifting mask (PSM), optical proximity correction and pupil filtering [1]. Currently, ArF lithography is applied to volume production, with both NA and k1 approaching the theoretical limits [2,3].…”

Benchmark of numerical versus analytical proximity curve calculations

“…The hp90 scenario is chosen as scalar imaging calculation without any pupil or lens apodization so that it is suitable for analytical calculation. The hp65 scenario [5] takes vectorial imaging effects into account and assumes a lens pupil apodization by considering the radiometric factor for an image reduction factor of 4. The bulk image computed by Solid is scaled by the refractive index, the threshold has to be adjusted accordingly.…”