Alternative EUV absorptive materials and novel architectures for EUV reticle in nm node technology scanner

Arash Edrisi

Research output: ThesisPd Eng ThesisAcademic

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Abstract

The 3D effects of typical EUVL masks worsen at higher numerical aperture of the imaging optics
employed in EUVL scanners. Therefore, the height of the EUV absorber layer of the reticle for
7nm node technology scanners necessarily should be reduced to the order of 30nm, as compared
to current Ta-based absorber heights which are around 50nm. Such a reduction of the absorber
height requires higher absorption per unit height or, more specifically, a higher absorption
coefficient. In this regard, the implementation of high EUV absorptive materials such as nickel
and silver were suggested. Nickel and silver grow polycrystalline which can be disadvantageous
in terms of the etching process used. Moreover, silver grows on ruthenium such that the surface
roughness is significantly unacceptable in terms of the surface roughness requirement for the
absorber layer of the reticle. As a result of these practical restrictions, two different designs were
suggested to overcome the practical issues; doping a nickel thin film with boron to suppress the
crystallization and a silver-germanium multilayer to suppress the crystallization and reduce the
surface roughness of the silver. The validations represented in section 7 showed both designs
successfully overcame the corresponding practical issues. Next, according to suggested designs,
full-size reticles must be fabricated to undergo further analyses by other stakeholders, such as
imaging tests, patterning, cleaning, and repair in order to provide further input to optimize and
validate final EUV absorber layers for 7nm node technology reticles.
Original languageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • Bijkerk, Fred, Supervisor
  • van de Kruijs, Robbert W.E., Co-Supervisor
Award date4 Mar 2019
Place of PublicationEnschede
Publisher
Publication statusPublished - 4 Mar 2019

Fingerprint

scanners
silver
reticles
absorbers
nickel
numerical aperture
cleaning
ruthenium
germanium
constrictions
surface roughness
boron
roughness
masks
etching
crystallization
requirements
thin films

Cite this

@phdthesis{b43164dbbc554d00999ec45a84f10e7a,
title = "Alternative EUV absorptive materials and novel architectures for EUV reticle in nm node technology scanner",
abstract = "The 3D effects of typical EUVL masks worsen at higher numerical aperture of the imaging opticsemployed in EUVL scanners. Therefore, the height of the EUV absorber layer of the reticle for7nm node technology scanners necessarily should be reduced to the order of 30nm, as comparedto current Ta-based absorber heights which are around 50nm. Such a reduction of the absorberheight requires higher absorption per unit height or, more specifically, a higher absorptioncoefficient. In this regard, the implementation of high EUV absorptive materials such as nickeland silver were suggested. Nickel and silver grow polycrystalline which can be disadvantageousin terms of the etching process used. Moreover, silver grows on ruthenium such that the surfaceroughness is significantly unacceptable in terms of the surface roughness requirement for theabsorber layer of the reticle. As a result of these practical restrictions, two different designs weresuggested to overcome the practical issues; doping a nickel thin film with boron to suppress thecrystallization and a silver-germanium multilayer to suppress the crystallization and reduce thesurface roughness of the silver. The validations represented in section 7 showed both designssuccessfully overcame the corresponding practical issues. Next, according to suggested designs,full-size reticles must be fabricated to undergo further analyses by other stakeholders, such asimaging tests, patterning, cleaning, and repair in order to provide further input to optimize andvalidate final EUV absorber layers for 7nm node technology reticles.",
author = "Arash Edrisi",
year = "2019",
month = "3",
day = "4",
language = "English",
publisher = "University of Twente",
address = "Netherlands",
school = "University of Twente",

}

Alternative EUV absorptive materials and novel architectures for EUV reticle in nm node technology scanner. / Edrisi, Arash .

Enschede : University of Twente, 2019. 80 p.

Research output: ThesisPd Eng ThesisAcademic

TY - THES

T1 - Alternative EUV absorptive materials and novel architectures for EUV reticle in nm node technology scanner

AU - Edrisi, Arash

PY - 2019/3/4

Y1 - 2019/3/4

N2 - The 3D effects of typical EUVL masks worsen at higher numerical aperture of the imaging opticsemployed in EUVL scanners. Therefore, the height of the EUV absorber layer of the reticle for7nm node technology scanners necessarily should be reduced to the order of 30nm, as comparedto current Ta-based absorber heights which are around 50nm. Such a reduction of the absorberheight requires higher absorption per unit height or, more specifically, a higher absorptioncoefficient. In this regard, the implementation of high EUV absorptive materials such as nickeland silver were suggested. Nickel and silver grow polycrystalline which can be disadvantageousin terms of the etching process used. Moreover, silver grows on ruthenium such that the surfaceroughness is significantly unacceptable in terms of the surface roughness requirement for theabsorber layer of the reticle. As a result of these practical restrictions, two different designs weresuggested to overcome the practical issues; doping a nickel thin film with boron to suppress thecrystallization and a silver-germanium multilayer to suppress the crystallization and reduce thesurface roughness of the silver. The validations represented in section 7 showed both designssuccessfully overcame the corresponding practical issues. Next, according to suggested designs,full-size reticles must be fabricated to undergo further analyses by other stakeholders, such asimaging tests, patterning, cleaning, and repair in order to provide further input to optimize andvalidate final EUV absorber layers for 7nm node technology reticles.

AB - The 3D effects of typical EUVL masks worsen at higher numerical aperture of the imaging opticsemployed in EUVL scanners. Therefore, the height of the EUV absorber layer of the reticle for7nm node technology scanners necessarily should be reduced to the order of 30nm, as comparedto current Ta-based absorber heights which are around 50nm. Such a reduction of the absorberheight requires higher absorption per unit height or, more specifically, a higher absorptioncoefficient. In this regard, the implementation of high EUV absorptive materials such as nickeland silver were suggested. Nickel and silver grow polycrystalline which can be disadvantageousin terms of the etching process used. Moreover, silver grows on ruthenium such that the surfaceroughness is significantly unacceptable in terms of the surface roughness requirement for theabsorber layer of the reticle. As a result of these practical restrictions, two different designs weresuggested to overcome the practical issues; doping a nickel thin film with boron to suppress thecrystallization and a silver-germanium multilayer to suppress the crystallization and reduce thesurface roughness of the silver. The validations represented in section 7 showed both designssuccessfully overcame the corresponding practical issues. Next, according to suggested designs,full-size reticles must be fabricated to undergo further analyses by other stakeholders, such asimaging tests, patterning, cleaning, and repair in order to provide further input to optimize andvalidate final EUV absorber layers for 7nm node technology reticles.

M3 - Pd Eng Thesis

PB - University of Twente

CY - Enschede

ER -