Elizabeth Lofano | IBM Research (original) (raw)
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Papers by Elizabeth Lofano
Advanced Energy Materials, 2018
ACS Applied Materials & Interfaces, 2016
Orientation control of thin film nanostructures derived from block copolymers (BCPs) are of great... more Orientation control of thin film nanostructures derived from block copolymers (BCPs) are of great interest for various emerging technologies like separation membranes, nanopatterning, and energy storage. While many BCP compositions have been developed for these applications, perpendicular orientation of these BCPs domains is still very challenging to achieve. Herein we report on a new, integration-friendly approach in which small amounts of a phase-preferential, surface active polymer (SAP) was used as an additive to a polycarbonate-containing BCP formulation to obtain perpendicularly oriented domains with 19 nm natural periodicity upon thermal annealing. In this work, the vertically oriented BCP domains were used to demonstrate next generation patterning applications for advanced semiconductor nodes. Furthermore, these domains were used to demonstrate pattern transfer into a hardmask layer using commonly used etch techniques and graphoepitaxy-based directed self-assembly using existing lithographic integration schemes. We believe that this novel formulationbased approach can be easily extended to other applications beyond nanopatterning.
Journal of Photopolymer Science and Technology, 2016
Advances in Resist Materials and Processing Technology XXVI, 2009
Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZE... more Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZEP function as high resolution and low roughness positive resists on the basis of radiation induced main chain scission to reduce the molecular weight while chemical amplification resists utilized in device manufacturing function on the basis of acidcatalyzed deprotection to change the polarity. In an attempt to increase the
SPIE Proceedings, 2012
ABSTRACT Electron beam resists develop a surface potential during exposure, which can lead to ima... more ABSTRACT Electron beam resists develop a surface potential during exposure, which can lead to image placement errors of up to several nanometers [1] and result in poor CD uniformity and image quality. To address this problem, we have synthesized a conductive polymer that can be coated onto a resist. Our conductive discharge layer (CDL) is water-soluble and is easily removed during subsequent processing steps. Having established that our material has a low enough resistance for full charge dissipation, we have carried out extensive tests to evaluate the impact of the layer on lithographic performance. We will report these findings, which include measurements of the effect of the CDL on the resolution, roughness, and speed of the resist.
Journal of Photopolymer Science and Technology, 2015
2 Outline § Background § Motivation: -Proc. SPIE 7972, 797218 (2011) -recent experimental results... more 2 Outline § Background § Motivation: -Proc. SPIE 7972, 797218 (2011) -recent experimental results § Materials analyzed -Bound PAG • Advantages of Bound PAG -Unbound PAG § E-beam vs EUV results comparison © 2011 IBM Corporation 3 Background: EUV vs e-beam § Similarities and differences in acid generation between e-beam (EB) and EUV by Prof Kozawa and Prof Tagawa (Jpn J. Appl. Phys. 49 (2010)): -Both radiation based phenomena -Photoacids interact with low energy electrons deposited in resist materials via ionization -EUV has a larger efficiency in acid yield Material EUV E-beam 193nm correlation Commercial 193 resist (IBM/LBNL) terrible good good bad Commercial EUV Resist (Albany) good good good good
Journal of Photopolymer Science and Technology, 2014
ABSTRACT To extend the scaling beyond the most widely used poly(styrene-b-methyl methacrylate) (P... more ABSTRACT To extend the scaling beyond the most widely used poly(styrene-b-methyl methacrylate) (PS-b-PMMA), organic high-χ block copolymers (BCPs) were developed. Vertically oriented BCP domains were obtained by simple coat and bake process without application of an additional layer of a topcoat material. In addition, process-friendly conditions including low bake temperature (< 200 °C) and short bake time (≤ 5 min) provided a simple scheme to integrate these high-χ block copolymers to standard lithography process and pre-patterns defined by 193i lithography. Successful demonstration of directed self-assembly of these high-χ block copolymers on 193i-defined guiding pre-patterns offers a simple route to access well-aligned perpendicular lamellae and cylinders with a pitch less than 20 nm.
Advances in Resist Materials and Processing Technology XXVI, 2009
Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZE... more Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZEP function as high resolution and low roughness positive resists on the basis of radiation induced main chain scission to reduce the molecular weight while chemical amplification resists utilized in device manufacturing function on the basis of acidcatalyzed deprotection to change the polarity. In an attempt to increase the
Advances in Resist Materials and Processing Technology XXIX, 2012
Advanced Energy Materials, 2018
ACS Applied Materials & Interfaces, 2016
Orientation control of thin film nanostructures derived from block copolymers (BCPs) are of great... more Orientation control of thin film nanostructures derived from block copolymers (BCPs) are of great interest for various emerging technologies like separation membranes, nanopatterning, and energy storage. While many BCP compositions have been developed for these applications, perpendicular orientation of these BCPs domains is still very challenging to achieve. Herein we report on a new, integration-friendly approach in which small amounts of a phase-preferential, surface active polymer (SAP) was used as an additive to a polycarbonate-containing BCP formulation to obtain perpendicularly oriented domains with 19 nm natural periodicity upon thermal annealing. In this work, the vertically oriented BCP domains were used to demonstrate next generation patterning applications for advanced semiconductor nodes. Furthermore, these domains were used to demonstrate pattern transfer into a hardmask layer using commonly used etch techniques and graphoepitaxy-based directed self-assembly using existing lithographic integration schemes. We believe that this novel formulationbased approach can be easily extended to other applications beyond nanopatterning.
Journal of Photopolymer Science and Technology, 2016
Advances in Resist Materials and Processing Technology XXVI, 2009
Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZE... more Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZEP function as high resolution and low roughness positive resists on the basis of radiation induced main chain scission to reduce the molecular weight while chemical amplification resists utilized in device manufacturing function on the basis of acidcatalyzed deprotection to change the polarity. In an attempt to increase the
SPIE Proceedings, 2012
ABSTRACT Electron beam resists develop a surface potential during exposure, which can lead to ima... more ABSTRACT Electron beam resists develop a surface potential during exposure, which can lead to image placement errors of up to several nanometers [1] and result in poor CD uniformity and image quality. To address this problem, we have synthesized a conductive polymer that can be coated onto a resist. Our conductive discharge layer (CDL) is water-soluble and is easily removed during subsequent processing steps. Having established that our material has a low enough resistance for full charge dissipation, we have carried out extensive tests to evaluate the impact of the layer on lithographic performance. We will report these findings, which include measurements of the effect of the CDL on the resolution, roughness, and speed of the resist.
Journal of Photopolymer Science and Technology, 2015
2 Outline § Background § Motivation: -Proc. SPIE 7972, 797218 (2011) -recent experimental results... more 2 Outline § Background § Motivation: -Proc. SPIE 7972, 797218 (2011) -recent experimental results § Materials analyzed -Bound PAG • Advantages of Bound PAG -Unbound PAG § E-beam vs EUV results comparison © 2011 IBM Corporation 3 Background: EUV vs e-beam § Similarities and differences in acid generation between e-beam (EB) and EUV by Prof Kozawa and Prof Tagawa (Jpn J. Appl. Phys. 49 (2010)): -Both radiation based phenomena -Photoacids interact with low energy electrons deposited in resist materials via ionization -EUV has a larger efficiency in acid yield Material EUV E-beam 193nm correlation Commercial 193 resist (IBM/LBNL) terrible good good bad Commercial EUV Resist (Albany) good good good good
Journal of Photopolymer Science and Technology, 2014
ABSTRACT To extend the scaling beyond the most widely used poly(styrene-b-methyl methacrylate) (P... more ABSTRACT To extend the scaling beyond the most widely used poly(styrene-b-methyl methacrylate) (PS-b-PMMA), organic high-χ block copolymers (BCPs) were developed. Vertically oriented BCP domains were obtained by simple coat and bake process without application of an additional layer of a topcoat material. In addition, process-friendly conditions including low bake temperature (< 200 °C) and short bake time (≤ 5 min) provided a simple scheme to integrate these high-χ block copolymers to standard lithography process and pre-patterns defined by 193i lithography. Successful demonstration of directed self-assembly of these high-χ block copolymers on 193i-defined guiding pre-patterns offers a simple route to access well-aligned perpendicular lamellae and cylinders with a pitch less than 20 nm.
Advances in Resist Materials and Processing Technology XXVI, 2009
Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZE... more Classical electron-beam resists such as poly(methyl methacrylate) (PMMA) and Nippon Zeon's ZEP function as high resolution and low roughness positive resists on the basis of radiation induced main chain scission to reduce the molecular weight while chemical amplification resists utilized in device manufacturing function on the basis of acidcatalyzed deprotection to change the polarity. In an attempt to increase the
Advances in Resist Materials and Processing Technology XXIX, 2012