Soft and Deep X-ray Lithography Beamline (BL-07)

Beamline overview

X-ray lithography using high intensity x-rays from synchrotron radiation (SR) sources (X-ray LIGA) is used for fabrication of high aspect ratio (10-500) micro-structures. Lithography at the soft X-ray range (photon energies from 1 to 3 keV) known as soft x-ray lithography (SXRL) achieves patterns with high lithographic resolution (< 100 nm). On the other hand, deep x-ray lithography (DXRL) is performed in hard X-ray region (> 4 keV), where few hundred microns of X-ray resist is exposed.

Soft and Deep X-ray lithography (SDXRL) beamline (BL-07) is a bending magnet based, high intensity beamline, that has been commissioned in April 2011

The Beamline
The Beamline
The  Mirror Box
The X-Ray Scanner
The Mirror Box
The X-Ray Scanner

Beamline parameters & Optical layout

This beamline consist of two mirrors system, beam position monitors, slits, Beryllium window and an x-ray scanner as experimental station. Platinum coated silicon mirrors (100 mm in width and 700 mm in length) are installed on a precision manipulator for transporting x-ray beam in the desired energy window to the experimental station at a fixed height. The first mirror is plane for defining x-ray energy cutoff and the second mirror is toroidal for vertical focusing and horizontal collimation. Depending upon the depth of the structures required in photo resist, the beamline can be operated in high energy, low energy and high flux or edge absorber modified flux (power) modes.

1. Low energy

Two mirror mode of operation : Energy band between 1.5-10 keV is available for SXRL and DXRL process. Beam sizes are variable between 2 mm (V) x 55 mm (H) to 10 mm (V) x 80 mm (H) (depending on the energy band required during exposure)

2. High Energy

Single mirror mode of operation : High energy and high flux, continuous energy spectrum from 5-10 keV. Beam sizes is 10 mm (V) x 100 mm (H).

3. High flux

White beam (No optics) mode of operation : High energy upto 40 keV is available to create high depth structures in photo resist. Beam sizes is 18 mm (V) x 100 mm (H).

BEAMLINE PARAMETERS
Energy Range1.5 keV – 20 keV
Beam Size at sample80 to 100 (H) x 2 to10 (V) mm2 (adjustable depending upon the beamline settings)
Filters 1,000-5,000


Optical layout of the SDXRL Beamline
Optical layout of the SDXRL Beamline
Mechanical design of the SDXRL beamline
Mechanical design of the SDXRL beamline

Experimental station

A custom designed and developed x-ray scanner for mask-resist exposure is installed in the experimental hutch. It scans the mask and resist assembly in vertical direction. It is possible to create three dimensional high aspect ratio micro-structures in Poly Methyl Metha Acrylate (PMMA) and SU-8 and other x-ray sensitive resists using tilt and rotation module apart from X-Y scanning of x-ray scanner. Infra Red camera images the temperature distribution of x-ray mask and resist. Temperature monitoring helps to prevent the degradation of resist and thus helps in fabrication of high quality of micro structures.

Features of X-ray Scanner
Exposure window± 90 mm (V), ± 40 mm (H)
Exposure EnvironmentVacuum, He-gas, Air(inside chamber)
Mask-Substrate Size Upto Circular Φ 100 mm and Square 100 mm × 100 mm
Photo resist thickness 1-5000 μm
Mask-Resist tilt and rotation tilt 0-90°and rotation ± 180°
Gap between mask and resist 0-100 μm
Speed of scanning stage 1-30 mm/s
Alignment accuracy between mask and resist~1 μm
(a) X-ray scanner system in Experimental Hutch, (b) Inside view of x-ray scanner, showing the mounted x-ray mask and resist on goniometer.
(a) X-ray scanner system in Experimental Hutch, (b) Inside view of x-ray scanner, showing the mounted x-ray mask and resist on goniometer.


(c) Beam at Experimental Station, (d) Gold based x-ray mask, (e)  Stainless steel x-ray mask.
(c) Beam at Experimental Station, (d) Gold based x-ray mask, (e) Stainless steel x-ray mask.


Energy power spectrum offered by the beamline
Energy power spectrum offered by the beamline

Application Areas

Quality structures consisting of micro-fluidic channel, micro-pillars, micro-cavities, high speed bearings, compound refractive lens etc have been fabricated using SDXRL beamline.

(1) Fabrication related to x-ray optics
Parabolic/cylindrical compound refractive lens
Parabolic/cylindrical compound refractive lens (CRL) on PMMA resist with geometrical aperture of 400 μm, radius is 200 μm at apex and N (no of lens) = 1, 2, 5, 10, 20, 50 are fabricated.

CRLs are designed for 9 keV x-ray energy. Wall thickness of the lens at the
(2) Fabrication related to micro-fluidics

A microfluidc channel based on ferro hydrodynamics
A microfluidc channel based on ferro hydrodynamics is fabricated on SU-8 with channel width of 400 μm and 600 μm and depth of 300-500 μm. Micro manipulation of Ferrofluid (Nickel ferrite nanoparticles dispersed in PEDG) is demonstrated. Ferrofluid speed is measured ~ 316 μm/s A microfluidc channel based on ferro hydrodynamics
(3) Fabrication of designed lattice
(3) Fabrication of designed lattice
(3) Fabrication of designed lattice
Curved neck, tapered holes fabricated in PMMA using innovative exposure techniques. The top diameter of tapered curved neck holes is 200μm and
Micro-pillars are fabricated on SU-8 at BL-07, 200 μm in diameter, 170 μm deep and 300μm pitch.


1. Puspen Mondal, Shweta Saundarkar, Nitin Khantwal, Pragya Tiwari and A. K. Srivastava,
“Fabrication of microfluidic channel of polydimethylsiloxane using X-ray lithography and its surface nanostructuring”
Journal of Micromanufacturing 1–9, 2021, DOI: 10.1177/25165984211015760
2. Thomas E. J. Moxham, David Laundy, Vishal Dhamgaye, Oliver J. L. Fox, Kawal Sawhney, and Alexander M. Korsunsky,
“Aberration characterization of x-ray optics using multi-modal ptychography and a partially coherent source”,
Appl. Phys. Lett. 118, 104104 (2021); https://doi.org/10.1063/5.0041341




1. Thomas E. J. Moxham, Aaron Parsons, Tunhe Zhou, Lucia Alianelli, Hongchang Wang, David Laundy, Vishal Dhamgaye, Oliver J. L. Fox, Kawal Sawhney and Alexander M. Korsunsky,
“Hard X-ray ptychography for optics characterization using a partially coherent synchrotron source”
J. Synchrotron Rad. (2020). 27, 1688–1695, https://doi.org/10.1107/S1600577520012151
2. Rahul Shukla, Harindra Kumar Kannojia, C. Mukherjee, P. Ram Sankar, B. S. Thakur, A. K. Sinha, Dhananjai Pandey,
“Challenges in fabrication of high aspect ratio electrostatic comb-drive microactuator using one-step X-ray lithography”,
ISSS Journal of Micro and Smart Systems, Nov. 2020, https://doi.org/10.1007/s41683-020-00064-z
3. Bhavishya B. Waghwani, Suroosh S. Ali, Shubham C, Anjankar, Suresh S. Balpande, Puspen Mondal, Jayu P. Kalambe,
“In vitro detection of water contaminants using microfluidic chip and luminescence sensing platform “,
Microfluidics and Nanofluidics (2020) 24:73, https://doi.org/10.1007/s10404-020-02381-z




1. David Laundy, Vishal Dhamgaye,Thomas Moxham, Kawal Sawhney,
“Adaptable refractive correctors for x-ray optics”,
Optica Vol. 6, No. 12 / December 2019 /1484, https://doi.org/10.1364/OPTICA.6.001484
2. David Laundy, Kawal Sawhney, Vishal Dhamgaye, Graham Duller, Gwyndaf Evans, Jose Trincao, and Anna Warren, “Optical elements for dynamically broadening the focus of micro-focus optics at synchrotron x-ray sources”, AIP Conference Proceedings 2054, 060006 (2019); https://doi.org/10.1063/1.5084637
3. Kawal Sawhney, David Laundy, Tom Moxham, Oliver Fox and Vishal Dhamgaye, “Development of pseudo-perfect x-ray optics using refractive compensators”, AIP Conference Proceedings 2054, 060003 (2019); https://doi.org/10.1063/1.5084634




1. Sonal Dhamgaye, Vishal Dhamgaye, Rekha Gadre,
“Growth Retardation at Different Stages of Bean Seedlings Developed from Seeds Exposed to Synchrotron X-Ray Beam”,
Advances in Biological Chemistry, 2018, 8, 29-35, DOI: 10.4236/abc.2018.82003





1. Rahul Shukla, Lala Abhinandan, Shivdutt Sharma,
“ Supercritical CO2 drying of poly (methyl methacrylate) photoresist for deep x-ray lithography: a brief note”,
J. Micro/Nanolith. MEMS MOEMS 16(3),034506 (2017), doi: 10.1117/1.JMM.16.3.034506.
2. Laundy David, Sawhney Kawal, Dhamgaye Vishal, Pape Ian,
“Refractive optics to compensate x-ray mirror shape-errors”,
Proc. SPIE 10386, Advances in X-Ray/EUV Optics and Components XII, 103860B (23 August 2017); doi: 10.1117/12.2275134
3. David Laundy, Kawal Sawhney and Vishal Dhamgaye,
“Using refractive optics to broaden the focus of an X-ray mirror”,
J. Synchrotron Rad. (2017). 24, 744–749, https://doi.org/10.1107/S1600577517006038
4. Paromita Sarbadhikarya,and Alok Dube,
“Enhancement of radiosensitivity of oral carcinoma cells by iodinated chlorin p6 copper complex in combination with synchrotron X-ray radiation”,
J. Synchrotron Rad. (2017). 24, 1265–1275, https://doi.org/10.1107/S1600577517012711



Science Highlights

Science Highlights

Science Highlights

Science Highlights

Team members

  1. Dr. A.K.Srivastava
  2. Dr. Pragya Tiwari
  3. Dr. Vishal Dhamgaye
  4. Shri Puspen Mondal
  5. Shri Nitin Khantwal
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