Impact of sequential infiltration synthesis on pattern fidelity of DSA lines

Abstract

Numerous block copolymer (BCP) systems can be used in directed self-assembly (DSA) processes to form patterns useful in lithography, especially lines and spaces with lamellar phase systems and vias/pillars with cylindrical phase systems. However, most of these BCP systems with attractive pattern formation capabilities have limited plasma etch contrast between the polymer domains. One potential solution to greatly enhance this etch contrast is a recently developed technique called sequential infiltration synthesis (SIS). SIS is a self-limiting synthesis technique, like atomic layer deposition, where organometallic (OM) precursor vapours and oxidants are introduced into self-assembled block copolymer systems in multiple cycles. In the first half of each cycle the OM precursor selectively reacts with one polymer domain, and in the second half of the cycle the oxidant reacts with the OM groups in the polymer film to selectively form metallic compounds in one of the polymer domains. Thus, the polymer pattern is transformed into a metallic mask with much enhanced plasma etch contrast. We report the effects of such a block-selective SIS process of metallic compounds on the feature sizes, roughness and profiles of patterns formed with BCP systems.

Sequential Infiltration of Self-Assembled Block Copolymers: A Study by Atomic Force Microscopy

“…Moreover, the self-limiting nature of SIS leads to final features in which changes in volume are minimal and can be controlled by varying the number of SIS cycles or other SIS parameters such as adsorption/purge time or temperature . With regard to the effect of infiltration on pattern quality, there is evidence of improved line edge roughness (LER), especially for low- and midfrequency roughness regimes, whereas surface roughness, another sensitive parameter, showed a modest increase after infiltration . Roughness analysis in ref was performed on the top surface of PMMA/SIS sub-100-nm lithographic patterns.…”

Nanoplasmonic Arrays with High Spatial Resolutions, Quality, and Throughput for Quantitative Detection of Molecular Analytes

“…We had earlier shown a high degree of control over the incorporation of the organometallic precursor by using atomic layer deposition, with the resulting oxide nanostructures enabling nanolithography down to sub-10 nm regime [35]. This was followed by several other investigations in literature focusing on vapor phase incorporation of metal-organic precursors within different block copolymer DOI: http://dx.doi.org/10.5772/intechopen.89064 domains using ALD processes [87][88][89][90][91]. It is important that the nanolithography process is optimized to not widen standard deviations between the features or across the wafer.…”

Three Dimensional Assembly in Directed Self-assembly of Block Copolymers

“…Following the back-etch process, the individual samples were stained using selective growth of Al 2 O 3 in the PMMA domain using sequential infiltration synthesis (SIS) process [14,15]. SIS process, which enables growth of metal oxides inside polymer and BCP films with high selectivity to BCP polar domains [16], can be used to enhance the etch contrast between the BCP domains and improve pattern transfer [17,18]. It was recently shown that SIS is also an excellent staining process for BCPs since it results in high imaging contrast and it is highly stable under the electron beam [14,15,19].…”