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CN-121985646-A - Light-emitting chip and preparation method thereof

CN121985646ACN 121985646 ACN121985646 ACN 121985646ACN-121985646-A

Abstract

The invention discloses a light-emitting chip and a preparation method thereof, wherein the light-emitting chip comprises a driving substrate, a first substrate and a second substrate, wherein the driving substrate comprises a first surface and a second surface which are oppositely arranged; the first surface comprises at least one electrode contact, at least one light-emitting unit which is positioned on the first surface of the driving substrate, and each light-emitting unit can be independently driven by the corresponding electrode contact, wherein the light-emitting unit comprises a light-emitting epitaxial structure which is in a spherical table shape, and the area of the top surface of the light-emitting epitaxial structure is smaller than that of the bottom surface of the light-emitting epitaxial structure. The technical scheme provided by the invention improves the light emitting efficiency of the light emitting chip.

Inventors

  • Request for anonymity

Assignees

  • 烟雨半导体(湖州)有限公司

Dates

Publication Date
20260505
Application Date
20260202

Claims (11)

  1. 1. A light emitting chip, comprising: The driving substrate comprises a first surface and a second surface which are oppositely arranged, wherein the first surface comprises at least one electrode contact; at least one light emitting unit located on the first surface of the driving substrate, each of the light emitting units being capable of being individually driven by a corresponding one of the electrode contacts; the light-emitting unit comprises a light-emitting epitaxial structure, the light-emitting epitaxial structure is in a spherical table shape, and the top surface area of the light-emitting epitaxial structure is smaller than the bottom surface area of the light-emitting epitaxial structure.
  2. 2. The light emitting chip of claim 1, wherein an angle between the arcuate sidewall of the light emitting epitaxial structure and the bottom surface of the light emitting epitaxial structure is 80 ° or less and 50 ° or more.
  3. 3. The light emitting chip of claim 1, further comprising: At least one microlens positioned on a side of the light emitting unit away from the driving substrate and on a side wall of the light emitting unit; The microlenses are formed from an inorganic dielectric material or an organic dielectric material in a spherical mesa shape based on the light emitting epitaxial structure.
  4. 4. A light emitting chip according to any one of claims 1 to 3, wherein the light emitting epitaxial structure comprises: a first semiconductor layer located at one side of the driving substrate; a light emitting layer located at one side of the first semiconductor layer away from the driving substrate; A second semiconductor layer located at one side of the light emitting layer away from the driving substrate; Wherein the first semiconductor layer and the second semiconductor layer are different in conductivity type.
  5. 5. The light-emitting chip according to claim 4, wherein the light-emitting unit further comprises: A first electrode between the light emitting epitaxial structure and the drive substrate, the first electrode being electrically connected to the electrode contact, and/or, The second electrode is positioned at one side of the light-emitting epitaxial structure far away from the driving substrate; wherein the material of the first electrode comprises metal, and the material of the second electrode comprises transparent conductive material.
  6. 6. The light-emitting chip according to claim 5, wherein an overall structure formed by the second electrode and the light-emitting epitaxial structure is in a spherical table shape.
  7. 7. The light emitting chip of claim 5, further comprising: The passivation layer is positioned on the side wall of the light emitting unit and the first surface of the driving substrate which is not covered by the light emitting unit; The electrode connecting layer is positioned on the surface of the passivation layer, which is far away from the light-emitting epitaxial structure, the surface of the passivation layer, which is far away from the driving substrate, and the surface of the second electrode, which is far away from the light-emitting epitaxial structure; the ohmic contact layer is positioned between the first electrode and the first semiconductor, and the material of the ohmic contact layer, the material of the electrode connecting layer and the material of the second electrode comprise zinc tin oxide; Wherein, the contour of the lower surface of the micro lens in the light-emitting chip is matched with the contour of the upper surface of the electrode connecting layer.
  8. 8. A method for manufacturing a light emitting chip, which is used for manufacturing the light emitting chip according to any one of claims 1 to 7, comprising: providing a substrate, and forming an epitaxial layer on the substrate; bonding the driving substrate on one side of the epitaxial layer far away from the substrate, and removing the substrate; Forming a composite mask on one side of the epitaxial layer far away from the driving substrate, and patterning the composite mask; And forming a spherical table-shaped epitaxial light-emitting structure based on the patterned composite mask, wherein the top surface area of the light-emitting epitaxial structure is smaller than the bottom surface area of the light-emitting epitaxial structure.
  9. 9. The method of manufacturing a light-emitting chip according to claim 8, wherein bonding the driving substrate on a side of the epitaxial layer away from the substrate comprises: Forming a first bonding sub-layer on one side of the epitaxial layer away from the substrate; Forming a second bonding sub-layer on the first surface of the driving substrate; Bonding the driving substrate on the side of the epitaxial layer far away from the substrate through the first bonding sub-layer and the second bonding sub-layer; after forming the spherical-table-shaped epitaxial light-emitting structure based on the patterned composite mask, the method further comprises the steps of: Etching the bonding layer to form a first electrode, wherein the first electrode is positioned between the light-emitting epitaxial structure and the driving substrate.
  10. 10. The method for manufacturing a light-emitting chip according to claim 8, wherein, Before the composite mask is formed on the side, away from the driving substrate, of the epitaxial layer, the method further comprises the following steps: Forming a second electrode material layer on the surface of one side of the epitaxial layer far away from the driving substrate, wherein a composite mask is formed on the surface of one side of the second electrode material layer far away from the epitaxial layer; Based on the patterned composite mask, the method forms a spherical table-shaped epitaxial light-emitting structure and simultaneously comprises the following steps: and forming a second electrode, wherein the integral structure formed by the second electrode and the light-emitting epitaxial structure is in a spherical table shape.
  11. 11. The method for manufacturing a light-emitting chip according to claim 8, further comprising: and forming microlenses on one side of the light emitting unit far from the driving substrate and on the side wall of the light emitting unit through a deposition process based on the shape of the light emitting epitaxial structure.

Description

Light-emitting chip and preparation method thereof Technical Field The embodiment of the invention relates to the technical field of display, in particular to a light-emitting chip and a preparation method thereof. Background Display technology is being developed continuously along with the deep development of an informationized and intelligent society as a key carrier for information exchange and intelligent interaction. Among many emerging display technologies, micro LED (Micro light emitting diode) display technologies are regarded as a next generation display scheme with subversion potential due to their excellent performances in terms of brightness, contrast, power consumption, lifetime, etc., and show a wide application prospect in front-edge fields of Augmented Reality (AR), near-eye display (NED), wearable devices, etc. The Micro LED light-emitting chip is characterized in that a high-density and micrometer-scale two-dimensional array of pixel light-emitting units is integrated on a single chip. The mainstream Micro LED chip in the current industry mostly adopts a columnar or inverted trapezoid structure, and the manufacturing process mainly depends on the traditional planar semiconductor process and dry etching technology. In order to improve the light extraction efficiency, the prior art generally performs an oblique design on the chip side wall. However, even if the sidewall inclination angle is reduced to about 85 °, researches show that about 40% of photons are finally absorbed by the material after multiple reflections inside the chip, resulting in a significant reduction of optical efficiency. Therefore, how to improve the light emitting efficiency of the light emitting chip is a technical problem to be solved in the art. Disclosure of Invention The embodiment of the invention provides a light-emitting chip and a preparation method thereof, which are used for improving the light-emitting efficiency of the light-emitting chip. According to an aspect of the present invention, there is provided a light emitting chip including: The driving substrate comprises a first surface and a second surface which are oppositely arranged, wherein the first surface comprises at least one electrode contact; at least one light emitting unit located on the first surface of the driving substrate, each of the light emitting units being capable of being individually driven by a corresponding one of the electrode contacts; the light-emitting unit comprises a light-emitting epitaxial structure, the light-emitting epitaxial structure is in a spherical table shape, and the top surface area of the light-emitting epitaxial structure is smaller than the bottom surface area of the light-emitting epitaxial structure. Optionally, an included angle between the arc-shaped side wall of the light-emitting epitaxial structure and the bottom surface of the light-emitting epitaxial structure is smaller than or equal to 80 degrees and larger than or equal to 50 degrees. Optionally, the light emitting chip further includes: At least one microlens positioned on a side of the light emitting unit away from the driving substrate and on a side wall of the light emitting unit; The microlenses are formed from an inorganic dielectric material or an organic dielectric material in a spherical mesa shape based on the light emitting epitaxial structure. Optionally, the light emitting epitaxial structure includes: a first semiconductor layer located at one side of the driving substrate; a light emitting layer located at one side of the first semiconductor layer away from the driving substrate; A second semiconductor layer located at one side of the light emitting layer away from the driving substrate; Wherein the first semiconductor layer and the second semiconductor layer are different in conductivity type. Optionally, the light emitting unit further includes: a first electrode between the light emitting epitaxial structure and the drive substrate, the first electrode being electrically connected to the electrode contact, and/or, The second electrode is positioned at one side of the light-emitting epitaxial structure far away from the driving substrate; wherein the material of the first electrode comprises metal, and the material of the second electrode comprises transparent conductive material. Optionally, the integral structure formed by the second electrode and the light-emitting epitaxial structure is in a spherical table shape. Optionally, the light emitting chip further includes: The passivation layer is positioned on the side wall of the light emitting unit and the first surface of the driving substrate which is not covered by the light emitting unit; The electrode connecting layer is positioned on the surface of the passivation layer, which is far away from the light-emitting epitaxial structure, the surface of the passivation layer, which is far away from the driving substrate, and the surface of the second electrode, which is far away f