Laser ablation of high-aspect-ratio hole arrays in tungsten for X-ray applications

Chantal M. Silvestre*, Jens H. Hemmingsen, Erik S. Dreier, Jan Kehres, Ole Hansen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Periodic two-dimensional tungsten X-ray optical gratings were fabricated using a combination of pico-second laser ablation and wet chemical etch. A 200 μm thick cold-rolled sheet of tungsten (99.97%) was used as base material for the fabrication of a 1.5 × 1.5 cm2 periodic grating with an array of circular holes of approximately 12:1 aspect ratio. The laser parameters were optimized to obtain through-hole diameters slightly smaller than the desired final dimension. Subsequent wet etching was used to precisely control the diameter of through-holes. The through-hole profile was characterized using scanning electron microscopy (SEM) and showed a slight conical shape with a slope of 1.3%. The two-dimensional tungsten absorption grating was successfully tested in an X-ray phase-contrast imaging setup. The method has proven to have some relevant benefits, such as good reproducibility and fairly easy fabrication due to few manufacturing steps.
Original languageEnglish
JournalMicroelectronic Engineering
Volume209
Pages (from-to)60-65
ISSN0167-9317
DOIs
Publication statusPublished - 2019

Keywords

  • High aspect ratio gratings
  • Laser ablation
  • Medical imaging
  • Phase-contrast imaging
  • Tungsten gratings
  • X-ray optics

Cite this

@article{7612e9336bcb4076baafd7203e8a9847,
title = "Laser ablation of high-aspect-ratio hole arrays in tungsten for X-ray applications",
abstract = "Periodic two-dimensional tungsten X-ray optical gratings were fabricated using a combination of pico-second laser ablation and wet chemical etch. A 200 μm thick cold-rolled sheet of tungsten (99.97{\%}) was used as base material for the fabrication of a 1.5 × 1.5 cm2 periodic grating with an array of circular holes of approximately 12:1 aspect ratio. The laser parameters were optimized to obtain through-hole diameters slightly smaller than the desired final dimension. Subsequent wet etching was used to precisely control the diameter of through-holes. The through-hole profile was characterized using scanning electron microscopy (SEM) and showed a slight conical shape with a slope of 1.3{\%}. The two-dimensional tungsten absorption grating was successfully tested in an X-ray phase-contrast imaging setup. The method has proven to have some relevant benefits, such as good reproducibility and fairly easy fabrication due to few manufacturing steps.",
keywords = "High aspect ratio gratings, Laser ablation, Medical imaging, Phase-contrast imaging, Tungsten gratings, X-ray optics",
author = "Silvestre, {Chantal M.} and Hemmingsen, {Jens H.} and Dreier, {Erik S.} and Jan Kehres and Ole Hansen",
year = "2019",
doi = "10.1016/j.mee.2019.03.007",
language = "English",
volume = "209",
pages = "60--65",
journal = "Microelectronic Engineering",
issn = "0167-9317",
publisher = "Elsevier",

}

Laser ablation of high-aspect-ratio hole arrays in tungsten for X-ray applications. / Silvestre, Chantal M.; Hemmingsen, Jens H.; Dreier, Erik S.; Kehres, Jan; Hansen, Ole.

In: Microelectronic Engineering, Vol. 209, 2019, p. 60-65.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Laser ablation of high-aspect-ratio hole arrays in tungsten for X-ray applications

AU - Silvestre, Chantal M.

AU - Hemmingsen, Jens H.

AU - Dreier, Erik S.

AU - Kehres, Jan

AU - Hansen, Ole

PY - 2019

Y1 - 2019

N2 - Periodic two-dimensional tungsten X-ray optical gratings were fabricated using a combination of pico-second laser ablation and wet chemical etch. A 200 μm thick cold-rolled sheet of tungsten (99.97%) was used as base material for the fabrication of a 1.5 × 1.5 cm2 periodic grating with an array of circular holes of approximately 12:1 aspect ratio. The laser parameters were optimized to obtain through-hole diameters slightly smaller than the desired final dimension. Subsequent wet etching was used to precisely control the diameter of through-holes. The through-hole profile was characterized using scanning electron microscopy (SEM) and showed a slight conical shape with a slope of 1.3%. The two-dimensional tungsten absorption grating was successfully tested in an X-ray phase-contrast imaging setup. The method has proven to have some relevant benefits, such as good reproducibility and fairly easy fabrication due to few manufacturing steps.

AB - Periodic two-dimensional tungsten X-ray optical gratings were fabricated using a combination of pico-second laser ablation and wet chemical etch. A 200 μm thick cold-rolled sheet of tungsten (99.97%) was used as base material for the fabrication of a 1.5 × 1.5 cm2 periodic grating with an array of circular holes of approximately 12:1 aspect ratio. The laser parameters were optimized to obtain through-hole diameters slightly smaller than the desired final dimension. Subsequent wet etching was used to precisely control the diameter of through-holes. The through-hole profile was characterized using scanning electron microscopy (SEM) and showed a slight conical shape with a slope of 1.3%. The two-dimensional tungsten absorption grating was successfully tested in an X-ray phase-contrast imaging setup. The method has proven to have some relevant benefits, such as good reproducibility and fairly easy fabrication due to few manufacturing steps.

KW - High aspect ratio gratings

KW - Laser ablation

KW - Medical imaging

KW - Phase-contrast imaging

KW - Tungsten gratings

KW - X-ray optics

U2 - 10.1016/j.mee.2019.03.007

DO - 10.1016/j.mee.2019.03.007

M3 - Journal article

VL - 209

SP - 60

EP - 65

JO - Microelectronic Engineering

JF - Microelectronic Engineering

SN - 0167-9317

ER -