Immersion lithography with an ultrahigh-NA in-line catadioptric lens and a high-transmission flexible polarization illumination system

Abstract

A second phase in the immersion era is starting with the introduction of ultra high NA (NA >1) systems. These systems are targeting for 45 nm node device production and beyond. ASML TWINSCAN XT:1700i features a maximum NA of 1.2 and a 26x33 mm 2 scanner field size. The projection lens is an in-line catadioptric lens design and the AERIAL XP illumination system enables conventional an off-axis illumination pupil shapes in either polarized or un-polarized modes at maximum light efficiency. In this paper a description and a performance overview of the TWINSCAN XT:1700i is given. We will present and discuss lithographic performance results, with special attention at low-k1 imaging using high NA and polarized illumination. Overlay, focus and productivity performance will also be presented.

Optimization of mask absorber stacks and illumination settings for contact hole imaging

“…The polarization of the source is defined by the intensity in the preferred state (IPS) [27]. An IPS value of 1.0 specifies perfect polarization according to the advanced polarization scheme of ASML-scanners [10], whereas IPS=0.5 corresponds to completely unpolarized light. The goal of the optimization run is to find a parameter setting with the largest overlap of process windows for IPS=1.0 and IPS=0.5, respectively.…”

“…Three different illumination options are considered in the optimization procedure: CQuad, Quadrupole, and Annular. A polarized illumination according to the advanced polarization scheme of ASML-scanners [10] is assumed in all cases. These assumptions result in the following four discrete and real valued variation parameters for the source optimization: type of illumination, σ inner , σ outer , and the opening angle Φ op of the poles.…”

EUV pellicle scanner integration for N2 nodes and beyond

“…The strong growth in computing power and data transport continues to drive evolution in Integrated Circuits (IC), and associated further increases in pattern density, as described by Moore's law 1 . This is being enabled by advances in all processing steps, but mainly by continuous advances in photolithography, by decreasing the (UV) wavelength and increasing the numerical aperture of the photolithographic tools (also known as scanners) and introducing resolution enhancements such as polarization 2 and immersion 3 . The introduction of Extreme Ultra-Violet (EUV) scanners into high-volume manufacturing has ensured that Moore's law can continue for the coming decade at least 4 .…”

High-power optical elements for 13.5 nm EUV

“…Innovations in photolithographic systems, also called scanners, are key in reducing power consumption and increasing computing performance in coming years, while simultaneously reducing the cost per die by allowing more dies on a wafer by the shrinking of all dimensions of all basic IC structures 1 . These innovations may be evolutionary, such as introducing polarization 2 and immersion 3 to extend the resolution for UV exposure wavelengths or by increasing the numerical aperture of the lithographic exposure tool. In the past years, a revolutionary step has been made with the introduction of 13.5 nm EUV as a new exposure wavelength to improve resolution towards the 10-20 nm range 4 .…”