Immersion lithography: New opportunities for semiconductor manufacturing

Abstract

A new purged UV spectroscopic ellipsometer to characterize thin films and multilayers at 157 nm AIP Conf.Immersion lithography has recently emerged as the preferred lithography solution for manufacturing the next generation of semiconductor devices (likely to address the 65, 45, and possibly the 32 nm nodes). Full-field immersion scanners operating at = 193 nm with de-ionized water as the immersion fluid have been recently demonstrated. In this article we report imaging results from the AT1150i prototype, a 0.75 numerical-aperture full-field scanner from ASML. We experimentally confirm the depth-of-focus improvements that immersion enables, and explore the implications of this gain for semiconductor manufacturing. This article also highlights the challenges the technology faces before it can be successfully introduced for semiconductor manufacturing. We pay particular attention to defects, in the form of particles, bubbles, and other processing residues, and highlight evaporation as a key mechanism underpinning these challenges.

Enhancement of near-field phase-shifting contact lithography by immersion technique

“…Hence, improvement in resolution by immersion unfortunately does not support any reduction in feature size. These conclusions regarding resolution enhancement appear to be validated by recent experimental studies as well [9,10].…”

“…These methods are generally called resolution enhancement techniques (RETs) [7]. One of the promising RETs that can be incorporated into NFPSCL is the immersion technique, which involves immersing the whole maskphotoresist-substrate system in a liquid medium (e.g., water) rather than air (conventional, dry environment) [8][9][10]. The refractive index of the immersion medium is certainly larger than that of air, which leads to higher spatial frequencies of light passing through the phaseshifting mask into the photoresist layer.…”

E-beam lithography experimental results and simulation for the 45-nm node

“…1 But moving to smaller k1 values required for 45 nm technologies by either increasing the NA or the use of polarization will still be dependent on the quality of masks and type of mask used. 2 Since the present plan is to stay with 4X reduction systems in the near future it is important to analyze the mask effects of CD distribution and MTT on the wafer.…”

The optical properties of monolayer amorphous Al2O3–TiO2 composite films used as HT-APSM blanks for ArF immersion lithography

“…Due to advances in the photoresist technologies plus the Cr assist features [2], the side-lobe effect can be minimized and the focus margin can be increased in the high transmittance APSM (HT-APSM) lithographic processes. The employing of HT-APSM to increase the resolution means that ArF immersion lithography could have the potential of reaching the 45 nm-or even the 32 nm-technology nodes [3] within the next two generations.…”