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US-12628545-B2 - Organic vapor jet printing system

US12628545B2US 12628545 B2US12628545 B2US 12628545B2US-12628545-B2

Abstract

A chuck for holding a workpiece in a deposition system is provided, which includes a base having a base surface with a flatness tolerance of not greater than 30 μm and a clamp having a surface configured to be attached to a substrate, which has a flatness tolerance of not greater than 30 μm. The clamp also includes a substrate holder configured to hold a substrate above the second clamp surface.

Inventors

  • Jeff HAWTHORNE
  • Sriram Krishnaswami
  • Kent Khuong NGUYEN

Assignees

  • UNIVERSAL DISPLAY CORPORATION

Dates

Publication Date
20260512
Application Date
20230124

Claims (19)

  1. 1 . A device for holding a workpiece in a material deposition system, the device comprising: a base having a base surface with a flatness tolerance of not greater than 30 μm; and a clamp comprising: a first clamp surface attached to the base surface; a second clamp surface configured to be attached to a substrate, the second clamp surface having a flatness tolerance of not greater than 30 μm; and a substrate holder configured to hold a substrate above the second clamp surface.
  2. 2 . The device of claim 1 , the substrate holder further comprising a vacuum chuck, a pressure-vacuum (PV) chuck, an electrostatic chuck, or a combination thereof.
  3. 3 . The device of claim 1 , wherein the flatness tolerance of the base surface is not greater than 20 μm.
  4. 4 . The device of claim 1 , wherein the flatness tolerance of the second clamp surface is not greater than 20 μm.
  5. 5 . The device of claim 4 , wherein the second clamp surface has a flatness tolerance of not greater than 0.5 μm.
  6. 6 . The device of claim 1 , wherein the second clamp surface is sufficient large to hold and support a substrate having a largest edge dimension of 3 m or more.
  7. 7 . The device of claim 6 , wherein the second clamp surface is sufficiently large to hold and support a substrate having a thickness of 7 mm or less.
  8. 8 . The device of claim 1 , further comprising a print engine disposed adjacent to the clamp such that a substrate held by the substrate holder is disposed between the print engine and the clamp.
  9. 9 . The device of claim 8 , wherein the flatness tolerance of the second clamp surface is not greater than 1 μm and the print engine extends across a width of at least 100 mm.
  10. 10 . The device of claim 1 , wherein the second clamp surface has the same flatness tolerance as the base surface.
  11. 11 . The device of claim 1 , wherein the base surface comprises glass and/or other dielectric materials.
  12. 12 . The device of claim 1 , wherein the base comprises a lattice structure.
  13. 13 . The device of claim 1 , wherein the base and/or the clamp comprise one or more through-holes for the substrate holder.
  14. 14 . The device of claim 13 , wherein the through-holes comprise gas channels for pressure and/or vacuum control.
  15. 15 . The device of claim 13 , further comprising lift pins disposed in and through the through-holes.
  16. 16 . The device of claim 1 , wherein the second clamp surface comprises raised features configured to provide for attachment of a substrate to the substrate holder.
  17. 17 . The device of claim 1 , wherein the device comprises materials that are ultra-high vacuum (UHV) compliant.
  18. 18 . A method of fabricating a pressure-vacuum chuck, the method comprising: obtaining a substrate support device having a first surface; and adjusting the flatness of the first surface using a closed-loop polishing process with optical interferometric measurement of a global surface flatness of the at least one surface.
  19. 19 . The method of claim 18 , wherein the substrate support device comprises: a base; and a clamp comprising: a first clamp surface attached to the base; a second clamp surface configured to be attached to a substrate; and a substrate holder configured to hold a substrate above the second clamp surface and comprising a vacuum chuck, a pressure-vacuum (PV) chuck, an electrostatic chuck, or a combination thereof; the method further comprising attaching the clamp and the base.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the priority benefit of U.S. Patent Application Ser. No. 63/308,455, filed Feb. 9, 2022, the entire contents of which are incorporated herein by reference. FIELD The present invention relates to devices and techniques for fabricating organic emissive devices, such as organic light emitting diodes, and devices and techniques including the same. BACKGROUND Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting diodes/devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants. OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety. One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Alternatively the OLED can be designed to emit white light. In conventional liquid crystal displays emission from a white backlight is filtered using absorption filters to produce red, green and blue emission. The same technique can also be used with OLEDs. The white OLED can be either a single EML device or a stack structure. Color may be measured using CIE coordinates, which are well known to the art. As used herein, the term “organic” includes polymeric materials as well as small molecule organic materials that may be used to fabricate organic opto-electronic devices. “Small molecule” refers to any organic material that is not a polymer, and “small molecules” may actually be quite large. Small molecules may include repeat units in some circumstances. For example, using a long chain alkyl group as a substituent does not remove a molecule from the “small molecule” class. Small molecules may also be incorporated into polymers, for example as a pendent group on a polymer backbone or as a part of the backbone. Small molecules may also serve as the core moiety of a dendrimer, which consists of a series of chemical shells built on the core moiety. The core moiety of a dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a “small molecule,” and it is believed that all dendrimers currently used in the field of OLEDs are small molecules. As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between. As used herein, “solution processible” means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium, either in solution or suspension form. A ligand may be referred to as “photoactive” when it is believed that the ligand directly contributes to the photoactive properties of an emissive material. A ligand may be referred to as “ancillary” when it is believed that the ligand does not contribute to the photoactive properties of an emissive material, although an ancillary ligand may alter the properties of a photoactive ligand. As used herein, and as would be generally understood by one skilled in the art, a first “Highest Occupied Molecular Orbital” (HOMO) or “Lowest Unoccupied Molecular Orbital” (LUMO) energy level is “greater than” or “higher than” a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since ionization potentials (IP) are measured as a negative energy relative to a vacuum level, a higher HOMO energy level corresponds to an IP having a smaller absolute value (an IP that is less negative).