CN-121985638-A - Flip LED chip capable of improving brightness and preparation method thereof

CN121985638ACN 121985638 ACN121985638 ACN 121985638ACN-121985638-A

Abstract

The invention discloses a flip LED chip capable of improving brightness and a preparation method thereof, wherein a transparent conducting layer is prepared and generated on a P-GaN layer, a first insulating layer and a second insulating layer are sequentially deposited on the transparent conducting layer, and the second insulating layer covers the surface of the LED chip with the prepared transparent conducting layer; etching to generate conductive holes communicated with the P-GaN layer at the positions corresponding to the P-GaN layers of the first insulating layer and the second insulating layer according to preset intervals, etching at the positions corresponding to the N-GaN layers of the first insulating layer and the second insulating layer and exposing the N-GaN layers, evaporating to form a metal layer on the outer surface of the second insulating layer, enabling the metal layer to fill the conductive holes to form contact interfaces with the P-GaN layers, enabling the metal layer to extend to the exposed area of the N-GaN layers and cover at least part of the surface of the N-GaN layers, and depositing to form a third insulating layer and a fourth insulating layer which are stacked in sequence on the metal layer. The invention improves the overall brightness and reliability of the flip LED chip without significantly increasing the forward voltage.

Inventors

ZHENG ZHIYING
ZHANG CHUYUE
ZHANG BOYANG
CHEN BINGYANG
CAI HAIFANG

Assignees

福州华兆光电有限公司

Dates

Publication Date: 20260505
Application Date: 20260123

Claims (10)

1. The preparation method of the flip LED chip for improving the brightness is characterized by comprising the following steps of: S1, sequentially etching on a substrate to generate an N-GaN layer, a quantum well layer and a P-GaN layer; S2, preparing and generating a transparent conducting layer on the P-GaN layer, and sequentially depositing a first insulating layer and a second insulating layer on the transparent conducting layer, wherein the second insulating layer covers the surface of the LED chip on which the transparent conducting layer is prepared; S3, etching to generate conductive holes communicated with the P-GaN layer at the positions of the first insulating layer and the second insulating layer corresponding to the P-GaN layer according to a preset interval, and etching to expose the N-GaN layer at the positions of the first insulating layer and the second insulating layer corresponding to the N-GaN layer; S4, evaporating and forming a metal layer on the outer surface of the second insulating layer, filling the conductive hole by the metal layer, forming a contact interface with the P-GaN layer, and enabling the metal layer to extend to the exposed area of the N-GaN layer and cover at least part of the surface of the N-GaN layer; And S5, depositing and forming a third insulating layer and a fourth insulating layer which are stacked in sequence on the metal layer, wherein the fourth insulating layer covers the surface of the LED chip with the prepared metal layer.
2. The method for manufacturing a flip-chip LED chip with improved brightness according to claim 1, wherein in step S3, conductive holes connecting the P-GaN layers are etched at predetermined intervals at positions of the first insulating layer and the second insulating layer corresponding to the P-GaN layers, specifically comprising: And forming a plurality of conductive holes penetrating through the first insulating layer and communicated with the P-GaN layer on the first insulating layer and the second insulating layer according to a preset interval with the corresponding region of the P-GaN layer, wherein the conductive holes are distributed in an equilateral triangle array mode in the plane direction.
3. The method for manufacturing a flip-chip LED chip with improved brightness according to claim 2, wherein the preset pitch is in the range of 30-50 μm and the diameter of the conductive via is in the range of 8-12 μm.
4. The method for manufacturing a flip-chip LED chip with improved brightness according to claim 1, wherein in step S3, etching is performed at a position of the first insulating layer and the second insulating layer corresponding to the N-GaN layer to expose at least a part of the N-GaN layer, and the method specifically comprises: Etching is carried out at the positions of the first insulating layer and the second insulating layer corresponding to the N-GaN layer so as to expose at least part of the N-GaN layer, and the geometric center of the exposed area of the N-GaN layer is limited to be located at a first preset interval from the edge of the second insulating layer.
5. The method of manufacturing a flip-chip LED chip with increased brightness according to claim 4, wherein said first predetermined interval is in the range of 5-15 μm.
6. The method for manufacturing a flip-chip LED chip with improved brightness according to claim 1, wherein said step S4 further comprises: And limiting the minimum distance between the metal layer and the first insulating layer to be in a second preset interval on the contact surface of the metal layer and the N-GaN layer.
7. The method of manufacturing a flip-chip LED chip with increased brightness according to claim 6, wherein the second preset interval is in the range of 0-4 μm.
8. The method for manufacturing a flip-chip LED chip with improved brightness according to claim 1, wherein said step S2 specifically comprises: S21, preparing and generating a transparent conductive layer on the P-GaN layer; s22, depositing and forming a first insulating layer and a second insulating layer which are stacked in sequence on the transparent conducting layer, wherein the first insulating layer at least covers the P-GaN layer, the number of the second insulating layers is at least one, and at least one layer of the second insulating layer covers the surface of the LED chip with the transparent conducting layer.
9. The method for manufacturing a flip-chip LED chip with improved brightness according to claim 1, wherein the first insulating layer and the third insulating layer are made of aluminum oxide, aluminum nitride or silicon oxynitride, and the second insulating layer and the fourth insulating layer are made of silicon dioxide.
10. The flip LED chip for improving the brightness comprises an N-GaN layer, a quantum well layer, a P-GaN layer and a transparent conductive layer which are sequentially prepared on a substrate, and is characterized by further comprising: A first insulating layer and a second insulating layer sequentially deposited over the transparent conductive layer; the metal layer is formed on the surface of the second insulating layer by evaporation and is electrically connected with the P-GaN layer and the N-GaN layer respectively; and a third insulating layer and a fourth insulating layer are sequentially deposited above the metal layer.

Description

Flip LED chip capable of improving brightness and preparation method thereof Technical Field The invention relates to the technical field of LEDs, in particular to a flip LED chip capable of improving brightness and a preparation method thereof. Background Light Emitting Diodes (LEDs) are widely used in the field of lighting and display as an efficient and energy-saving solid state light source. With the continuous improvement of the requirements of the application scene on brightness and light efficiency, the flip LED chip is widely adopted due to the short current diffusion path and good heat dissipation performance. In the flip-chip structure, in order to improve the light extraction efficiency of the chip, a metal layer with higher reflectivity is generally disposed on one side of the P-type gallium nitride layer, so as to reflect the light generated inside the chip and propagating downwards, thereby improving the light extraction efficiency. However, the high-reflection metal material commonly used in the prior art has good reflection performance, and meanwhile, the high-reflection metal material is easy to migrate and cause reliability problems such as electric leakage, so that coverage range of the high-reflection metal material is usually limited or a larger distance is kept between the high-reflection metal material and the edge of the P-GaN layer, and therefore effective area of a reflection layer is limited, and the brightness enhancement space of a chip is limited. In addition, the insulation structure design of the existing flip LED chip between the metal layer and the semiconductor layer is multi-layered and single-layer protection, so that the improvement of the reflection efficiency and the long-term electrical stability are difficult to be considered at the same time, and further improvement is still left. Disclosure of Invention The invention aims to solve the technical problem of providing the flip LED chip capable of improving the overall brightness and the preparation method thereof. In order to solve the technical problems, the invention adopts the following technical scheme: a preparation method of a flip LED chip for improving brightness comprises the following steps: S1, sequentially etching on a substrate to generate an N-GaN layer, a quantum well layer and a P-GaN layer; S2, preparing and generating a transparent conducting layer on the P-GaN layer, and sequentially depositing a first insulating layer and a second insulating layer on the transparent conducting layer, wherein the second insulating layer covers the surface of the LED chip on which the transparent conducting layer is prepared; S3, etching to generate conductive holes communicated with the P-GaN layer at the positions of the first insulating layer and the second insulating layer corresponding to the P-GaN layer according to a preset interval, and etching to expose the N-GaN layer at the positions of the first insulating layer and the second insulating layer corresponding to the N-GaN layer; S4, evaporating and forming a metal layer on the outer surface of the second insulating layer, filling the conductive hole by the metal layer, forming a contact interface with the P-GaN layer, and enabling the metal layer to extend to the exposed area of the N-GaN layer and cover at least part of the surface of the N-GaN layer; And S5, depositing and forming a third insulating layer and a fourth insulating layer which are stacked in sequence on the metal layer, wherein the fourth insulating layer covers the surface of the LED chip with the prepared metal layer. In order to solve the technical problems, the invention adopts another technical scheme that: The flip LED chip capable of improving brightness comprises an N-GaN layer, a quantum well layer, a P-GaN layer and a transparent conductive layer which are sequentially prepared on a substrate, and further comprises: A first insulating layer and a second insulating layer sequentially deposited over the transparent conductive layer; the metal layer is formed on the surface of the second insulating layer by evaporation and is electrically connected with the P-GaN layer and the N-GaN layer respectively; and a third insulating layer and a fourth insulating layer are sequentially deposited above the metal layer. The flip LED chip for improving the brightness and the preparation method thereof have the beneficial effects that the first insulating layer and the second insulating layer are arranged between the transparent conducting layer and the metal layer, and the third insulating layer and the fourth insulating layer are further arranged on the outer side of the metal layer, so that the metal layer is clamped between the multi-layer insulating structures, and on the premise that the metal layer is reliably and electrically connected with the P-GaN layer and the N-GaN layer respectively, the metal migration and the leakage risk are effectively inhibited, the metal layer is allowed to be