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CN-122003073-A - Light-emitting display device, method for manufacturing the same, and light-emitting display system

CN122003073ACN 122003073 ACN122003073 ACN 122003073ACN-122003073-A

Abstract

The invention relates to a method for manufacturing a light emitting display device from a precursor comprising a plurality of island structures arranged on a substrate, each island structure comprising a support layer extending over the substrate, and a conductive layer extending over the support layer, the island structures being separated by trenches, the method comprising the steps of filling the trenches with insulating structural elements, forming a guard strip covering each island structure only partially and covering the structural elements, partially etching the structural elements, forming pillars under the guard strip, providing the guard strip with overhanging portions, depositing an organic layer, forming two separate portions, a first portion extending continuously over each island structure and the guard strip, and a second portion extending over the substrate. The invention also relates to a light emitting display device comprising at least one trench, at least one guard strip, at least one pillar and an organic layer. The invention also relates to a luminous display system.

Inventors

  • Clement Barlot
  • Adrian Gas
  • GUNTHER HAAS

Assignees

  • 法国原子能及替代能源委员会
  • 麦克罗欧莱德公司

Dates

Publication Date
20260508
Application Date
20251104
Priority Date
20241104

Claims (19)

  1. 1. A method (300) of manufacturing a light emitting display device (200) from a precursor (100), the precursor (100) comprising a plurality of island structures (101) arranged on a substrate (102), each island structure (101) comprising a support layer (104) extending over the substrate (102), and a conductive layer (103) extending over the support layer (104), the island structures being separated by trenches (106), the method (300) comprising the steps of: -filling each trench (106) separating the island structures (101) with a structural element (107) electrically insulating the island structures (101), the filling proceeding for each trench (106) until the structural element (107) reaches the top of the island structures (101) separated by the trench; -forming at least one guard strip (108), each guard strip (108) connecting two island structures (101) to each other by spanning a trench (102) separating the two island structures (101) and covering a structural element (107) extending in the trench (106), each guard strip (108) only partially covering each of the two island structures (101) to which it is connected; -selectively partially etching the structural element (107) with respect to the conductive layer (103) of each guard strip (108) and island structure (101), the partial etching comprising at least one isotropic etching stage, the partial etching proceeding to leave only a portion (109) of the structural element (107) disposed under each guard strip (108), said portion (109) forming a post of each guard strip (108), the partial etching further proceeding to at least a portion (110 a, 110 b) of each guard strip (108) overhanging extending beyond the post (109) supporting it, and -Anisotropically depositing the organic layer (201) at an angle substantially perpendicular to the substrate (102), forming two distinct and separate portions (201-1, 201-2) of the organic layer (201), comprising a first portion (201-1) extending continuously over each island (101) and each guard strip (108), and a second portion (201-2) extending over the substrate (102), the deposition thickness of the organic layer (201) being selected such that the second portion (203) of the organic layer (201) does not reach the at least one overhanging portion (110 a, 110 b) of each guard strip (108).
  2. 2. The method (300) according to claim 1, wherein the step of partially etching the structural element (107) proceeds to a lateral gap (D110) of the at least one overhang portion (110 a, 110 b) of each guard strip (108) with respect to the support (109) supporting it strictly greater than 100 nm.
  3. 3. The method (300) according to claim 1 or 2, characterized in that for each trench (106) filling is performed to a height of 10 to 100nm of the structural element (107) beyond the conductive layer (103) of the two island structures (101) separated by the trench.
  4. 4. A method (300) according to claim 3, characterized in that each island structure (101) comprises a sacrificial layer (105) extending over the conductive layer (103) before filling each trench (106), the step of filling each trench (106) with a structural element (107) being performed until the structural element (107) reaches the top of the sacrificial layer (105) extending over the island structure (101).
  5. 5. The method (300) of claim 4, further comprising selectively etching the sacrificial layer (105) of each island (101) with respect to the structural element (107) after filling each trench (106) and before forming each guard strip (108), the etching proceeding to the conductive layer (103) of the island (101).
  6. 6. The method (300) according to claim 4 or 5, wherein for each trench (106) filling with a structural element (107) comprises the steps of: -depositing a layer of electrically insulating material to completely fill the trench (106); Polishing the layer of insulating material until the sacrificial layer (105) of each island (101) is reached.
  7. 7. The method (300) according to claim 4 or 5, wherein for each trench (106) filling with a structural element (107) comprises the steps of: -conformally depositing (conformally depositing) a dielectric layer in the trench (106); -depositing a layer of filling material on the dielectric layer to completely fill the trench (106); Polishing the dielectric layer and the filling layer until the sacrificial layer (105) of each island structure (101) is reached.
  8. 8. The method (300) of claim 7, wherein the filler material is amorphous silicon or polysilicon.
  9. 9. The method (300) according to any one of claims 1 to 8, comprising, prior to forming each guard strip (108), creeping or expanding the structural element (107) so that it covers a portion of the conductive layer of each island (101), forming at least one continuous ridge-free surface extending from the conductive layer (103) of one island (101) to the conductive layer of the other island (101), each free surface having an inclination angle of-45 degrees to 45 degrees, preferably-20 degrees to +20 degrees, with respect to the substrate (102).
  10. 10. The method (300) according to any one of claims 1 to 9, wherein each guard strip (108) is electrically insulating.
  11. 11. The method (300) according to any one of claims 1 to 10, wherein partially etching the structural element (107) comprises at least one anisotropic etching stage and at least one isotropic etching stage (e.g. alternating), each anisotropic etching stage being performed with a directionality substantially perpendicular to the substrate (102).
  12. 12. The method (300) according to any one of claims 1 to 11, comprising anisotropically depositing an additional conductive layer (204) after depositing the organic layer (201), forming two distinct and separate portions (204-1, 204-2) of the additional conductive layer (204), comprising a first portion (204-1) of the additional conductive layer (204) extending continuously over the first portion (201-1) of the organic material layer (201), and a second portion (204-2) of the additional conductive layer (204) extending over the second portion (2021-2) of the organic layer (201), the deposition thickness of the additional conductive layer (204) being selected such that the second portion (204-2) of the additional conductive layer (204) does not touch at least one cantilever portion (110 a, 110 b) of each protective strip.
  13. 13. The method (300) according to any one of claims 1 to 12, wherein the partially etching the structural element (107) further proceeds to partially etch the support layer (104) of each island structure (101) such that for each island structure (101) at least a portion (114) of the conductive layer (103) of the island structure (101) overhangs the support layer (104) of the island structure (101).
  14. 14. A light emitting display device (200) comprising a plurality of island structures (101) disposed on a substrate (102), each island structure comprising a support layer (104) extending over the substrate (102) and a conductive layer (103) extending over the support layer (104), the device further comprising: -at least one trench (106) for separating the island-like structures (101) two by two; -at least one guard strip (108), each guard strip connecting two island structures (101) by crossing a trench (106) separating the two island structures (101), and each guard strip (108) only partially covering each (101) of the connected two island structures; -at least one pillar (109) at least partially filling the trench (106) and electrically insulating the island structures (101) separated by the trench (106), each pillar (109) reaching or exceeding the height of the two island structures (101) separated by the trench, and each pillar (109) being arranged below the guard strip (108) to support the guard strip (108) such that at least a portion (110 a, 110 b) of the guard strip (108) extends to overhang the pillar (109); -an organic layer (201) having two separate and mutually separated portions (201-1, 201-2), comprising a first portion (201-1) extending continuously over each island (101) and each guard strip (108), and comprising a second portion (201-2) extending over the substrate (102) without touching the at least one overhanging portion (110 a, 110 b) of each guard strip (108).
  15. 15. The display device (200) of claim 14, wherein the at least one overhang (110 a, 110 b) of each guard strip (108) is strictly greater than 100 nanometers with respect to a lateral gap (D110) of a pillar (109) supporting it.
  16. 16. The display device (200) according to claim 14 or 15, wherein the at least one pillar (109) is made of an electrically insulating material.
  17. 17. The display device (200) according to any one of claims 14 to 16, wherein the at least one pillar (109) comprises a dielectric layer for electrically insulating the island structures (101) separated by the at least one pillar (109), and a filler material for supporting the guard strip (108)), and wherein the dielectric layer of the at least one pillar separates the filler material of the at least one pillar from each island structure (101).
  18. 18. The display device (200) according to any one of claims 14 to 16, wherein the at least one pillar (109) has a continuous ridgeless surface over which the guard strips (108) extend, and which extends from the conductive layer (103) of one island (101) to the conductive layer (103) of the other island (101), the continuous ridgeless surface having an inclination angle with respect to the substrate (102) of between-45 degrees and 45 degrees, preferably between-20 degrees and +20 degrees.
  19. 19. A light emitting display system comprising a display device (200) according to any of claims 14 to 18, and an active addressing matrix comprising a plurality of transistors, each transistor being connected to a conductive layer (103) of one island structure (101) in the display device (200).

Description

Light-emitting display device, method for manufacturing the same, and light-emitting display system Technical Field The invention belongs to the technical field of optoelectronic devices, and particularly relates to a matrix display device with an organic light-emitting layer. The present invention relates to a method of manufacturing an Organic Light Emitting Diode (OLED) type light emitting display device, and to a method of manufacturing such a type device. The invention can be advantageously applied to the manufacture of display screens for electronic devices, in particular to the manufacture of high resolution color display screens, such as Active Matrix Organic Light Emitting Diode (AMOLED) display screens. "high resolution" herein refers to pixel sizes less than 15 microns. Background In the field of matrix display devices with organic light emitting layers, OLED-type matrix microdisplays with pixel pitches smaller than 20 micrometers (typically between 4 micrometers and 12 micrometers) are known. When such a matrix display is color, each pixel is subdivided into sub-pixels of different colors (typically red, green, and blue) that cooperate to emit light of the desired color. The surface shape of the sub-pixels may be rectangular, square or other shapes (e.g., octagons), the size of which may vary from color to color. Typical dimensions for the sub-pixels range from 1 micron to 20 microns. Each subpixel is typically composed of a plurality of superimposed layers including a lower electrode (anode) deposited on a common substrate, a plurality of organic layers (at least one of which is a light emitting layer) forming an OLED stack on each lower electrode, and an upper electrode (cathode). Patent documents FR3079909A1 and US2023/0041252A1 disclose structures for forming such small-sized OLED pixels (or OLED subpixels) and having improved industrial reliability. A common advantage of these structures is the ability to smooth discretization of the OLED stack and cathode to form pixels (or sub-pixels). "smooth discretization" refers to a structuring method that can preserve the stacking properties of the OLED. In particular, the solution provided discretizes the OLED stack by means of a non-masking and removal step, since masking and removal steps generally require environments (humidity, temperatures above 90 ℃, solvents, uv rays, etc.) that are harmful to the organic materials. Accordingly, patent document FR3079909A1 discloses a first OLED display device in which the lower electrode of each sub-pixel is separated from each other by an insulating wall protruding perpendicularly from the substrate, each wall acting as a spacer between two adjacent sub-pixels. The same document FR3079909 also discloses a second device in which the insulating walls are replaced by trenches on which an insulating layer is deposited. The insulating walls and trenches are formed prior to depositing the OLED stack by thermal evaporation and serve the same function. Since the vapor deposition technique is primarily directional, the OLED stack is preferentially deposited on the horizontal walls of the device rather than on the insulating walls or sidewalls of the trench. Thus, the OLED stack breaks (or discretizes) at the insulating walls or trenches. However, in practical applications, the directionality of the OLED stack deposition never reaches a fully ideal state. Thus, organic particles may also be deposited on the insulating walls or the sidewalls of the trenches. These particles are undesirable because they reduce the insulating properties (electrical and optical) between the sub-pixels. Adjacent sub-pixels may then interact, for example by capacitive coupling or parasitic currents. These phenomena, known as crosstalk, can lead to reduced performance of the display device. These phenomena are exacerbated when the sub-pixels are so-called "tandem" organic light emitting diodes, i.e. the sub-pixels comprise a plurality of OLED stacks stacked in series by means of interconnect layers. Patent document US2023/0041252A1 provides a solution to this problem, which discloses a sub-pixel spacer provided on a substrate and having a mushroom-shaped structure (or the term "overhang structure" used in this document). More specifically, the mushroom-shaped structure includes a lower portion (mushroom stem) having inclined sides, and an upper portion wider than the lower portion, the upper portion shielding one area of the substrate. The upper part forms a mushroom cap. The sub-pixels are formed after the mushroom shaped structures are in place. The OLED stack is then deposited on these structures and disconnected at the top. The disconnection of the OLED stack has a satisfactory reliability since the organic material cannot be deposited on the substrate area or the sidewalls of the mushroom structure that are shielded by the upper portion (the lower portion cannot be contacted from above due to the shielding by the upper portion). There