Search

EP-4735376-A1 - LITHOGRAPHIC MASKING DEVICE AND PARALLEL-FLOW PROVIDER DEVICE FOR A STOP FLOW LITHOGRAPHY APPARATUS

EP4735376A1EP 4735376 A1EP4735376 A1EP 4735376A1EP-4735376-A1

Abstract

A lithographic masking device for a stop flow lithography apparatus comprises a substrate, a lithographic mask arranged above the substrate, and a first flow channel defining an inner volume thereof. The substrate is adapted to transmit blue or UV light, wherein the blue or UV light comprises a wavelength in a wavelength range from 320 nm to 500 nm. Side portions and an upper portion of the first flow channel are arranged above the substrate, such that the inner volume of the flow channel is arranged above the lithographic mask and that a shortest distance between the lithographic mask and the inner volume of the first flow channel is at most 30 µm.

Inventors

  • TAIEDINEJAD, Ebrahim
  • DESTGEER, GHULAM
  • SAHIN, Mehmet Akif
  • WERNER, Helen
  • DIETZEL, ANDREAS
  • ERFLE, Peer

Assignees

  • Technische Universität München, in Vertretung des Freistaates Bayern

Dates

Publication Date
20260506
Application Date
20240517

Claims (20)

  1. 1. A lithographic masking device (10a) for a stop flow lithography apparatus (to), the lithographic masking device (10a) comprising: a substrate (16), wherein the substrate (16) is adapted to transmit blue or UV light, wherein the blue or UV light comprises a wavelength in a wavelength range from 320 nm to 500 nm; a lithographic mask (18) arranged above the substrate (16); and a first flow channel (2a) defining an inner volume (32) thereof; wherein side portions (30b) and an upper portion (30a) of the first flow channel (2a) are arranged above the substrate (16), such that the inner volume (32) of the first flow channel (2a) is arranged above the lithographic mask (18) and that a shortest distance between the lithographic mask (18) and the inner volume (32) of the first flow channel (2a) is at most 30 pm.
  2. 2. The lithographic masking device (10a) according to claim 1, wherein the inner volume (32) of the first flow channel (2a) is in direct physical contact with the lithographic mask (18).
  3. 3. The lithographic masking device (10a) according to claim 1 or claim 2, wherein the lithographic mask (18) is arranged inside the inner volume (32) of the first flow channel (2a).
  4. 4. The lithographic masking device (10a) according to any of the preceding claims, wherein the side portions (30b) and/or the upper portion (30a) of the first flow channel (2a) comprise(s) or is/are composed of a polymer material.
  5. 5. The lithographic masking device (10a) according to any of the preceding claims, wherein the side portions (30b) and/or the upper portion (30a) of the first flow channel (2a) are planar;
  6. 6. The lithographic masking device (10a) according to any of the preceding claims, wherein the first flow channel (2a) comprises a rectangular or quadratic inner cross section and/or outer cross section.
  7. 7. The lithographic masking device (10a) according to any of the preceding claims, wherein a footprint of the lithographic mask (18) on the substrate (16) is fully comprised in a footprint of the first flow channel (2a) on the substrate (16).
  8. 8. The lithographic masking device (10a) according to any of the preceding claims, wherein the lithographic mask (18) comprises openings (20) for transmitting the blue or UV light, and wherein a footprint of the openings (20) on the substrate (16) is fully comprised in a footprint of the first flow channel (2a) on the substrate (16), in particular between left and right inner walls (78) of the first flow channel (2a).
  9. 9. The lithographic masking device (10a) according to any of the preceding claims, wherein the first flow channel (2a) extends along a first direction (x) defined by a center line extending along the longitudinal direction of the first flow channel (2a) through its center, and wherein the lithographic mask (18) comprises openings (20).
  10. 10. The lithographic masking device (10a) according to claim 9, wherein widths of the openings (20) are less than too pm.
  11. 11. The lithographic masking device (10a) according to claim 9 or 10, wherein the openings (20) comprise first slit-shaped portions (20a), wherein longitudinal axes of the first slit-shaped portions (20a) are orientated perpendicular to the first direction (x).
  12. 12. The lithographic masking device (10a) according to claim 11, wherein widths of the first slitshaped portions (20a) are less than too pm.
  13. 13. The lithographic masking device (10a) according to claim 11 or 12, wherein the openings (20) comprise second slit-shaped portions (20b, 2ob-i, 2ob-2, 2ob-3, 2ob-4), wherein the second slit-shaped portions (20b, 2ob-i, 2ob-2, 2ob-3, 2ob-4) are connected to the first slitshaped portions (20a) and/or extend away from the first slit-shaped portions (20a).
  14. 14- The lithographic masking device (10a) according to claim 13, wherein widths of the second slit-shaped portions (20b, 2ob-i, 2ob-2, 2ob-3, 2ob-4) are less than too pm.
  15. 15. The lithographic masking device (10a) according to any of the previous claims, wherein the lithographic mask (18) comprises or is composed of a metal, such as gold or silver, or of ZnO.
  16. 16. The lithographic masking device (10a) according to any of the previous claims, wherein a thickness of the lithographic mask (18) is at most 1 pm.
  17. 17. The lithographic masking device (10a) according to any of the previous claims, wherein the lithographic masking device (10a) further comprises a first valve (34) adapted to stop the parallel flows of the fluids (40, 40-1, 40-2, 40-3, 40-4),
  18. 18. The lithographic masking device (10a) according to claim 17, wherein the first valve (34) is arranged in the first flow channel (2a) or in a downstream extension of the first flow channel (2a).
  19. 19. A parallel-flow provider device (10b) for providing parallel flows of fluids (40, 40-1, 40-2, 40-3, 40-4) for a stop flow lithography apparatus (10), the parallel-flow provider device (10b) comprising: a second flow channel (2b), comprising at least four inlet openings (6, 6-1, 6-2, 6-3, 6- 4) for introducing fluids into the second flow channel (2b), wherein the second flow channel (2b) extends along a second direction (x); at least three nozzle structures (4, 4-1, 4-2, 4-3) arranged in the second flow channel (2b) in series along the second direction (x), the nozzle structures (4, 4-1, 4-2, 4-3) comprising respective nozzle structure outlets (4a, 4a-i, 4a-2, 43-3), nozzle structure inlets (4b, 4b-i, 4b- 2, 4b-3), and nozzle structure bodies (4c, 4C-1, 4C-2, 4C-3, 4C-4), the nozzle structure bodies (4c, 4C-1, 4C-2, 4C-3, 4C-4) providing fluid-connections between the nozzle structure inlets (4b, 4b-i, 4b-2, 4b-3) and the respective nozzle structure outlets (4a, 4a-i, 4a-2, 43-3); wherein the inlet openings (6, 6-1, 6-2, 6-3, 6-4) and the nozzle structure inlets (4b, 4b- 1, 4b-2, 4b-3) are arranged alternatingly one after the other along the second direction (x).
  20. 20. The parallel-flow provider device (10b) according to claim 19, wherein a width of the nozzle structure outlets (4a, 4a-i, 4a-2, 43-3) or of at least one of the nozzle structure outlets (4a, 4a- 1, 4a-2, 43-3) is in a range from 60 pm to 90 pm, or in a range from 65 pm to 85 pm, or in a range from 70 pm to 80 pm.

Description

LITHOGRAPHIC MASKING DEVICE AND PARALLEL-FLOW PROVIDER DEVICE FOR A STOP FLOW LITHOGRAPHY APPARATUS TECHNICAL FIELD The disclosure relates to improvements in stop flow lithography, in particular to improve the size and shape control over the produced polymer particles, such as by improving the lithographic resolution and/or the control over the parallel flow of the precursor-containing fluids. BACKGROUND In stop flow lithography, a flow of a fluid containing a photochemical precursor is generated in a flow channel with a sub-millimeter diameter. This flow is temporarily stopped, such that the precursor-containing fluid is temporarily static inside the flow channel. While this is the case, the precursor-containing fluid is irradiated through a lithographic mask with blue or UV light to photo-induce a polymerization of the irradiated precursor. This process generates, from the polymerized precursor, polymer particles in the flow channel, with shapes determined by both the lithographic mask and the shape of the static, precursor-containing fluid in the flow channel. However, if the fluid is not perfectly static during the irradiation but still flows to some degree, this smears out the shape of the generated polymer particles. In other words, the accuracy to which the flow is stopped and becomes static, or to which a - typically undesired - flow remains, respectively, also determines the shape of the generated polymer particles. After the polymer particles have been generated, the flow of the precursor-containing fluid in the flow channel is restarted. The flow transports the generated polymer particles away from the region with the irradiation through the lithographic mask, and provides non-polymerized precursor-containing fluid to this region. The flow is stopped again, and the process is iterated. The generated polymer particles are collected at the end of the flow channel. OVERVIEW In view of the technical problems laid out above, there is a need for improvements in stop flow lithography. This objective is achieved with a lithographic masking device according to claim i, a parallel-flow provider device according to claim 19, a stop flow lithography apparatus according to claim 43, a stop flow lithography method according to claim 55, and with polymer particles according to claim 63. The dependent claims refer to advantageous embodiments. In a first aspect, a lithographic masking device for a stop flow lithography apparatus comprises a substrate, a lithographic mask arranged above the substrate, and a first flow channel defining an inner volume thereof. The substrate is adapted to transmit blue or UV light, wherein the blue or UV light comprises a wavelength in a wavelength range from 320 nm to 500 nm. Side portions and an upper portion of the first flow channel are arranged above the substrate, such that the inner volume of the first flow channel is arranged above the lithographic mask and that a shortest distance between the lithographic mask and the inner volume of the first flow channel is at most 30 pm. The upper portion of the first flow channel may alternatively be referred to as the upper wall of the first flow channel. The side portions of the first flow channel may alternatively be referred to as the side walls of the first flow channel. The first flow channel may be adapted to guide a flow through the first flow channel along the first direction. The substrate maybe adapted to transmit at least one wavelength in the wavelength range from 320 nm to 500 nm, for example, with a transmittance of at least 30% or at least 50% or at least 70%. As compared to the prior art, this arrangement reduces the distance between the lithographic mask and the inner volume of the flow channel, or to the polymer containing precursor which may be arranged therein, respectively, and thus improves the resolution of the lithographic process step. Consequently, the shape control over the generated polymer particles is improved, and particles can be fabricated with a higher resolution or with smaller sizes, in particular with sizes smaller than too pm. The short distance may be achieved by an additive process, such as 3D printing or two-photon printing, the side portions and the upper portion of the first flow channel onto the substrate with the lithographic mask arranged thereover. In contrast, in the prior art, the flow channel is produced separately from the lithographic mask, and the lithographic mask is added to the stop flow apparatus at a later stage. Consequently, in the prior art, the distance between the lithographic mask and the inner volume of the flow channel is at least in the range of a wall thickness of the flow channel, which is typically at least too pm. This large distance limits the lithographic resolution of the prior art devices. According to some embodiments, the inner volume of the first flow channel is in direct physical contact with the lithographic mask and/or the lithographic mask is arranged i