Polyimide planarization for increased transmission of large-area x-ray windows

Risto Mutikainen, Veli-Pekka Viitanen

Research output: Contribution to journalArticleScientificpeer-review

2 Citations (Scopus)

Abstract

The substrate roughness has previously set the limit for the minimum thickness of X-ray windows based on technology where planar tungsten grids are used for the membrane support, because the window membrane is built directly onto the substrate. Here this restriction is precluded by using a planarizing layer on the foil combined with retarded etchstop removal, which allows further reduction in the membrane thickness. A polyimide resin has been selected for the planarizing film, which can be removed either by solvents or by plasma etching. The fabrication process presented is capable of producing pressure-enduring X-ray window membranes in large formats down to the membrane polyimide thickness of 250 nm. The fabrication procedures of the windows are presented in detail to correlate the observed behaviour to the window structure. The test windows prepared are analyzed by pressure endurance and leak measurements and their X-ray transmission properties are presented.
Original languageEnglish
Pages (from-to)575-582
Number of pages8
JournalNuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Volume351
Issue number2-3
DOIs
Publication statusPublished - 1994
MoE publication typeA1 Journal article-refereed

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polyimides
Polyimides
Membranes
X rays
membranes
x rays
polyimide resins
Fabrication
Plasma etching
Substrates
fabrication
endurance
Metal foil
plasma etching
Tungsten
Durability
Resins
Surface roughness
format
foils

Cite this

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title = "Polyimide planarization for increased transmission of large-area x-ray windows",
abstract = "The substrate roughness has previously set the limit for the minimum thickness of X-ray windows based on technology where planar tungsten grids are used for the membrane support, because the window membrane is built directly onto the substrate. Here this restriction is precluded by using a planarizing layer on the foil combined with retarded etchstop removal, which allows further reduction in the membrane thickness. A polyimide resin has been selected for the planarizing film, which can be removed either by solvents or by plasma etching. The fabrication process presented is capable of producing pressure-enduring X-ray window membranes in large formats down to the membrane polyimide thickness of 250 nm. The fabrication procedures of the windows are presented in detail to correlate the observed behaviour to the window structure. The test windows prepared are analyzed by pressure endurance and leak measurements and their X-ray transmission properties are presented.",
author = "Risto Mutikainen and Veli-Pekka Viitanen",
note = "Project code: ELET3021",
year = "1994",
doi = "10.1016/0168-9002(94)91389-7",
language = "English",
volume = "351",
pages = "575--582",
journal = "Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment",
issn = "0168-9002",
publisher = "Elsevier",
number = "2-3",

}

Polyimide planarization for increased transmission of large-area x-ray windows. / Mutikainen, Risto; Viitanen, Veli-Pekka.

In: Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 351, No. 2-3, 1994, p. 575-582.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Polyimide planarization for increased transmission of large-area x-ray windows

AU - Mutikainen, Risto

AU - Viitanen, Veli-Pekka

N1 - Project code: ELET3021

PY - 1994

Y1 - 1994

N2 - The substrate roughness has previously set the limit for the minimum thickness of X-ray windows based on technology where planar tungsten grids are used for the membrane support, because the window membrane is built directly onto the substrate. Here this restriction is precluded by using a planarizing layer on the foil combined with retarded etchstop removal, which allows further reduction in the membrane thickness. A polyimide resin has been selected for the planarizing film, which can be removed either by solvents or by plasma etching. The fabrication process presented is capable of producing pressure-enduring X-ray window membranes in large formats down to the membrane polyimide thickness of 250 nm. The fabrication procedures of the windows are presented in detail to correlate the observed behaviour to the window structure. The test windows prepared are analyzed by pressure endurance and leak measurements and their X-ray transmission properties are presented.

AB - The substrate roughness has previously set the limit for the minimum thickness of X-ray windows based on technology where planar tungsten grids are used for the membrane support, because the window membrane is built directly onto the substrate. Here this restriction is precluded by using a planarizing layer on the foil combined with retarded etchstop removal, which allows further reduction in the membrane thickness. A polyimide resin has been selected for the planarizing film, which can be removed either by solvents or by plasma etching. The fabrication process presented is capable of producing pressure-enduring X-ray window membranes in large formats down to the membrane polyimide thickness of 250 nm. The fabrication procedures of the windows are presented in detail to correlate the observed behaviour to the window structure. The test windows prepared are analyzed by pressure endurance and leak measurements and their X-ray transmission properties are presented.

U2 - 10.1016/0168-9002(94)91389-7

DO - 10.1016/0168-9002(94)91389-7

M3 - Article

VL - 351

SP - 575

EP - 582

JO - Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

JF - Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

SN - 0168-9002

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ER -