CN211907459U - Vertical structure LED chip with double-sided transparent electrode - Google Patents

Abstract

The utility model discloses a vertical structure LED chip of two-sided transparent electrode, supreme support conducting substrate, bonding metal layer, protective metal layer, reflection metal layer, p face transparent electrode, epitaxial layer, passivation insulating layer and the transparent electrode of n face of including in proper order are down followed to the structure, wherein, the passivation insulating layer sets up the periphery of epitaxial layer, and with the epitaxial layer top forms first recess, n face transparent electrode bottom be provided with first recess assorted arch. The p-surface electrode adopts the transparent electrode, so that stable ohmic contact can be made, the voltage of the product is stable, the light transmittance performance is good, and the problem that the voltage of the LED chip in the traditional vertical structure is unstable is solved; in addition, because the n face electrode also adopts transparent electrode, can very big improvement current expansion to and avoid n electrode extinction to be in the light the problem, further promote luminance, reduce and send down the fever under the heavy current, promote the light efficiency, solve the not good problem of traditional vertical structure LED chip current expansion.

Description

Vertical structure LED chip with double-sided transparent electrode

Technical Field

The utility model relates to a LED chip makes technical field, in particular to vertical structure LED chip of two-sided transparent electrode.

Background

A Light Emitting Diode (LED) is a device that converts electrical energy into light energy by using a PN junction, and has the advantages of good controllability, fast start, long life, high light emitting efficiency, safety, energy saving, environmental protection, etc., and not only drives a deep revolution of the lighting industry, but also brings about innovation in the field of display screens.

With the development of the LED industry, high-power LEDs are more and more favored by people, in the high-power LEDs, vertical-structure LED chips are favored by various markets because of their good directions of being able to pass large current and emitting light, and various large LED chip factories also develop their own vertical-structure LED chip technologies, however, because the p-surface electrode of the current vertical-structure LED chip is a pure Ag electrode, although it has a higher reflectivity, it is not easy to make ohmic contact, and the voltage is unstable; in addition, the n-face electrode is local linear metal, the current is not well expanded, and the light is absorbed and blocked.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a vertical structure LED chip of two-sided transparent electrode can solve the technical problem that voltage instability and current expansion that traditional vertical structure LED chip exists are not good.

The technical scheme of the utility model is realized like this:

the utility model provides a vertical structure LED chip of two-sided transparent electrode, is including supporting conductive substrate, bonded metal layer, protective metal layer, reflection metal layer, p face transparent electrode, epitaxial layer, passivation insulating layer and n face transparent electrode, the bonded metal layer is installed support conductive substrate is last, the protective metal layer is installed on the bonded metal layer, the reflection metal layer is installed on the protective metal layer, p face transparent electrode is installed on the reflection metal layer, the epitaxial layer is installed on the p face transparent electrode, the passivation insulating layer sets up the periphery of epitaxial layer, and with the epitaxial layer top forms first recess, n face transparent electrode bottom be provided with first recess assorted arch.

As a further alternative of the LED chip with the vertical structure of the double-sided transparent electrode, a second groove is formed in the top of the n-sided transparent electrode.

As a further alternative of the vertical structure LED chip with the double-sided transparent electrode, the passivation insulating layer includes a pillar insulating layer disposed on the periphery of the epitaxial layer and a pillar insulating layer disposed on the top of the epitaxial layer.

As a further alternative of the LED chip with the vertical structure of the double-sided transparent electrode, the p-side transparent electrode is made of any one transparent conductive material of graphene, ITO, ZnO and Ga2O3, and the thickness of the p-side transparent electrode is 5nm-10000 nm.

As a further alternative of the LED chip with the vertical structure of the double-sided transparent electrode, the n-sided transparent electrode is made of any one transparent conductive material of graphene, ITO, ZnO and Ga2O3, and the thickness of the n-sided transparent electrode is 5nm-10000 nm.

As a further alternative of the vertical structure LED chip with the double-sided transparent electrode, the protective metal layer is a multi-metal lamination of Ti, TiW, Pt, Ni, Cr and Au, and the thickness of the protective metal layer is 100nm-5000 nm.

As a further alternative of the LED chip with the vertical structure and the double-sided transparent electrode, the bonding metal layer is any one of a stack of Ni and Sn, Ag and Sn, Au and eutectic alloy, and the thickness of the bonding metal layer is 100nm-5000 nm.

As a further alternative of the LED chip with the vertical structure and the double-sided transparent electrode, the passivation insulating layer is made of any one of SiO2, SiN and polyimide, and the thickness of the passivation insulating layer is 50nm-10000 nm.

As a further alternative of the LED chip with the vertical structure and the double-sided transparent electrode, the supporting conductive substrate is made of any one of monocrystalline silicon, monocrystalline germanium, polycrystalline silicon, polycrystalline germanium, Cu, W and Al, and the thickness of the supporting conductive substrate is 50-400 um.

As a further alternative of the LED chip with the vertical structure of the double-sided transparent electrode, the reflective metal layer is any one of a NiAg stack layer and an Al metal, and the epitaxial layer is a light-emitting GaN layer grown on a silicon-based or sapphire or SiC substrate.

A preparation method of a vertical structure LED chip with double-sided transparent electrodes comprises the following steps:

step S1, growing an epitaxial layer on the silicon substrate to form an LED epitaxial wafer;

step S2, growing a p-surface transparent electrode on the LED epitaxial wafer;

step S3, covering a reflecting metal layer on the p-surface transparent electrode and the epitaxial layer;

step S4, covering a protective metal layer and a bonding metal layer on the whole surface of the reflection metal layer;

step S5, fabricating a bonding metal layer on the supporting conductive substrate;

step S6, bonding the samples obtained in the step S4 and the step S5;

step S7, removing the substrate of the epitaxial layer;

step S8, carrying out rough treatment on the epitaxial layer;

step S9, making a square or rectangular chip pattern from the roughly processed sample, and then making a pattern required by a user;

step S10, forming a passivation insulating material by using CVD or evaporation or photoetching method, and forming a square or rectangle which corresponds to the shape of the chip and is smaller than the step S9 by using photoetching and etching methods, so that the passivation insulating material covers the side section of the chip to form a passivation insulating layer;

step S11, growing an n-face transparent electrode on the epitaxial layer and the passivation insulating layer;

and step S12, cutting and scribing to form single double-sided transparent electrode LED chips, and completing preparation.

The utility model has the advantages that: by adopting the vertical structure LED chip with the double-sided transparent electrode, the p-side electrode adopts the transparent electrode, so that stable ohmic contact can be made, the voltage of a product is stable, the light transmission performance is good, and the problem of unstable voltage of the traditional vertical structure LED chip is solved; in addition, because the n face electrode also adopts transparent electrode, can very big improvement current expansion to and avoid n electrode extinction to be in the light the problem, further promote luminance, reduce and send down the fever under the heavy current, promote the light efficiency, solve the not good problem of traditional vertical structure LED chip current expansion.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a vertical-structure LED chip with a double-sided transparent electrode according to the present invention;

fig. 2 is an assembly schematic diagram of a passivation insulating layer and an epitaxial layer in a vertical structure LED chip with a double-sided transparent electrode according to the present invention;

fig. 3 is a schematic diagram illustrating the composition of the passivation insulating layer in the LED chip with the vertical structure of the double-sided transparent electrode according to the present invention;

fig. 4 is a schematic diagram illustrating the composition of an n-side transparent electrode in a vertical structure LED chip with a double-side transparent electrode according to the present invention;

fig. 5 is a flow chart of a method for manufacturing a vertical structure LED chip with a double-sided transparent electrode according to the present invention;

description of reference numerals: 1. supporting a conductive substrate; 2. bonding the metal layer; 3. a protective metal layer; 4. a reflective metal layer; 5. a p-side transparent electrode; 6. an epitaxial layer; 7. passivating the insulating layer; 8. an n-face transparent electrode; 9. a first groove; 701. an upright column insulating layer; 702. a cross-pillar insulating layer; 801. a protrusion; 802. a second groove.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it should be apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 1 to 5, an LED chip with a vertical structure of a double-sided transparent electrode includes a supporting conductive substrate 1, a bonding metal layer 2, a protective metal layer 3, a reflective metal layer 4, a p-side transparent electrode 5, an epitaxial layer 6, a passivation insulating layer 7, and an n-side transparent electrode 8, the bonding metal layer 2 is mounted on the supporting conductive substrate 1, the protective metal layer 3 is mounted on the bonding metal layer 2, the reflective metal layer 4 is mounted on the protective metal layer 3, the p-side transparent electrode 5 is mounted on the reflective metal layer 4, the epitaxial layer 6 is arranged on the p-surface transparent electrode 5, the passivation insulating layer 7 is arranged on the periphery of the epitaxial layer 6, and a first groove 9 is formed on the top of the epitaxial layer 6, and a protrusion 801 matched with the first groove 9 is arranged at the bottom of the n-face transparent electrode 8.

In the embodiment, the p-surface electrode adopts the transparent electrode, so that stable ohmic contact can be made, the voltage of the product is stable, the light transmittance is good, and the problem that the voltage of the LED chip with the traditional vertical structure is unstable is solved; in addition, since the n-face electrode also adopts the transparent electrode, the current expansion can be greatly improved, the problem that the n-face electrode absorbs light and blocks light is avoided, the brightness is further improved, the heat emission under large current is reduced, the light efficiency is improved, and the problem that the current expansion of the traditional vertical structure LED chip is poor is solved;

preferably, the top of the n-side transparent electrode 8 is provided with a second groove 802.

Preferably, the passivation insulating layer 7 includes a pillar insulating layer 701 disposed on the periphery of the epitaxial layer 6 and a pillar insulating layer 702 disposed on the top of the epitaxial layer 6.

Preferably, the p-surface transparent electrode 5 is made of any one transparent conductive material of graphene, ITO, ZnO and Ga2O3, and the thickness of the p-surface transparent electrode 5 is 5nm-10000 nm; it should be noted that the p-side transparent electrode 5 may also be made of other transparent conductive materials.

Preferably, the n-face transparent electrode 8 is made of any one transparent conductive material of graphene, ITO, ZnO and Ga2O3, and the thickness of the n-face transparent electrode 8 is 5nm-10000 nm; it should be noted that the n-side transparent electrode 8 may also be made of other transparent conductive materials.

Preferably, the protective metal layer 3 is a multi-metal stack of Ti, TiW, Pt, Ni, Cr and Au, and the thickness of the protective metal layer 3 is 100nm to 5000 nm.

Preferably, the bonding metal layer 2 is any one of a stack of Ni and Sn, Ag and Sn, Au, and eutectic alloy, and the thickness of the bonding metal layer 2 is 100nm to 5000 nm.

In this embodiment, the bonding metal layer 2 may use Ni and Sn as a preparation material, Ag and Sn as a preparation material, Au and Sn as a preparation material, a stacked layer of Au as a preparation material, or a eutectic alloy as a preparation material.

Preferably, the passivation insulating layer 7 is made of any one insulating material of SiO2, SiN and polyimide, and the thickness of the passivation insulating layer 7 is 50nm-10000 nm; it should be noted that other insulating materials can also be used as the preparation material for the passivation insulating layer 7.

Preferably, the supporting conductive substrate 1 is made of any one of monocrystalline silicon, monocrystalline germanium, polycrystalline silicon, polycrystalline germanium, Cu, W and Al, and the thickness of the supporting conductive substrate 1 is 50um-400 um; it is to be noted that the single crystal silicon, single crystal germanium, polycrystalline silicon, and polycrystalline germanium must be highly conductive.

Preferably, the reflective metal layer 4 is any one of a NiAg stack layer and an Al metal, and the epitaxial layer 6 is a light-emitting GaN layer grown on a silicon-based or sapphire or SiC substrate; it should be noted that other metals with high reflectivity and good ohmic contact can be used for the reflective metal layer 4.

A preparation method of a vertical structure LED chip with double-sided transparent electrodes comprises the following steps:

step S1, growing an epitaxial layer 6 on a substrate of silicon, sapphire, SiC or the like by using MOCVD to form an LED epitaxial wafer;

step S2, growing a p-surface transparent electrode 5 on the LED epitaxial wafer by using a CVD or PVD or evaporation or spin coating mode;

step S3, covering a reflecting metal layer 4 on the p-surface transparent electrode 5 and the epitaxial layer 6 in an electron beam evaporation or PVD mode;

step S4, covering the whole surface of the reflecting metal layer 4 with a protective metal layer 3 and a bonding metal layer 2 by using an electron beam evaporation or PVD method;

step S5, manufacturing a bonding metal layer on the supporting conductive substrate 1 by using an electron beam evaporation or PVD method;

step S6, bonding the samples obtained in step S4 and step S5;

step S7, removing the substrate of the epitaxial layer 6 by grinding, chemical etching or plasma etching or laser stripping;

step S8, roughening the epitaxial layer 6 by chemical liquid reduction or acid solution or graphical etching method to facilitate light emergence;

step S9, using photoetching method to make square or rectangle chip pattern, then using hot acid solution or using inductance coupling plasma etching method to make needed pattern;

step S10, forming a passivation insulating material by using CVD or evaporation or photoetching method, and forming a square or rectangle corresponding to the shape of the chip but smaller than (9) by using photoetching and etching method, so that the passivation insulating material covers the side section of the chip to form a passivation insulating layer 7;

step S11, growing an n-face transparent electrode 8 on the epitaxial layer 6 and the passivation insulating layer 7 by CVD or PVD or evaporation or spin coating;

and step S12, cutting and scratching to form a single double-sided transparent electrode LED chip through testing, and completing preparation.

Embodiment 1 of the method for manufacturing a vertical-structure LED chip with double-sided transparent electrodes:

(1) growing an LED epitaxial wafer of an epitaxial layer of 2um-8um on a Si substrate by using an MOCVD epitaxial technology;

(2) respectively using acetone and isopropanol to carry out organic cleaning for 5min to remove organic dirt;

(3) then using SPM solution to carry out acid cleaning to remove inorganic metal dirt and organic dirt;

(4) flushing and spin-drying, and growing 200nm graphene at 300 ℃ by using CVD equipment;

(5) and (4) evaporating Al metal by electron beam on the whole surface for 200 nm.

(6) Electron beam evaporation of TiPtTiPt (Ti20nm-200nm, Pt20nm-300nm) protective layer and NiSn (Ni100nm-800nm, Sn100nm-2000nm) bonding metal layer

(7) And (3) evaporating a NiSn (Ni100nm-800nm, Sn100nm-2000nm) bonding metal layer on the high-conductivity Si substrate by adopting an electron beam evaporation process.

(8) And (3) bonding the samples manufactured in the steps (10) and (11) by using a bonding machine, and removing the silicon substrate by using grinding and chemical etching methods.

(9) The chip after the silicon substrate is removed is roughened by using hot alkaline solution, the percentage concentration of the KOH aqueous solution is 0.05-10%, and the temperature is 20-100 ℃.

(10) The method comprises the steps of manufacturing a square LED pattern (1005um to 1005um) covered by glue by using a photoetching method, and etching the epitaxial layer region without the glue by using phosphoric acid to form a cutting channel.

(11) Growing SiO2 with the thickness of 600nm by using PECVD equipment;

(12) the pattern is made by using a photoetching technology, and is matched with the LED pattern but is smaller than 10um, and the hollow pattern is 995um x 995 um; etching the SiO2 corresponding to the pattern by using a BOE solution, removing the photoresist and drying;

(13) and growing 1000nm graphene by using a CVD (chemical vapor deposition) device.

(14) And cutting the channel by using laser, splitting by using a splitter, expanding the film to form a single LED chip, and manufacturing the LED chip with the double-sided transparent electrode by the above process.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The LED chip with the vertical structure and the double-sided transparent electrode is characterized by comprising a supporting conductive substrate (1), a bonding metal layer (2), a protective metal layer (3), a reflective metal layer (4), a p-side transparent electrode (5), an epitaxial layer (6), a passivation insulating layer (7) and an n-side transparent electrode (8), wherein the bonding metal layer (2) is arranged on the supporting conductive substrate (1), the protective metal layer (3) is arranged on the bonding metal layer (2), the reflective metal layer (4) is arranged on the protective metal layer (3), the p-side transparent electrode (5) is arranged on the reflective metal layer (4), the epitaxial layer (6) is arranged on the p-side transparent electrode (5), the passivation insulating layer (7) is arranged on the periphery of the epitaxial layer (6) and forms a first groove (9) with the top of the epitaxial layer (6), and the bottom of the n-surface transparent electrode (8) is provided with a bulge (801) matched with the first groove (9).

2. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 1, wherein the top of the n-sided transparent electrode (8) is provided with a second groove (802).

3. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 2, wherein the passivation insulating layer (7) comprises a pillar insulating layer (701) disposed at the periphery of the epitaxial layer (6) and a pillar insulating layer (702) disposed at the top of the epitaxial layer (6).

4. The LED chip with the vertical structure and the double-sided transparent electrode as claimed in claim 3, wherein the p-side transparent electrode (5) is made of any one transparent conductive material selected from graphene, ITO, ZnO and Ga2O3, and the thickness of the p-side transparent electrode (5) is 5nm-10000 nm.

5. The vertical structure LED chip of the double-sided transparent electrode as claimed in claim 4, wherein the n-sided transparent electrode (8) is made of any one transparent conductive material selected from graphene, ITO, ZnO and Ga2O3, and the thickness of the n-sided transparent electrode (8) is 5nm-10000 nm.

6. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 5, characterized in that the protective metal layer (3) is a multi-metal stack of Ti, TiW, Pt, Ni, Cr and Au, and the thickness of the protective metal layer (3) is 100nm-5000 nm.

7. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 6, wherein the bonding metal layer (2) is any one of a stack and eutectic alloy of Ni and Sn, Ag and Sn, Au, and the thickness of the bonding metal layer (2) is 100nm-5000 nm.

8. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 7, wherein the passivation insulating layer (7) is any one of SiO2, SiN and polyimide, and the thickness of the passivation insulating layer (7) is 50nm-10000 nm.

9. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 8, wherein the supporting conductive substrate (1) is made of any one of monocrystalline silicon, monocrystalline germanium, polycrystalline silicon, polycrystalline germanium, Cu, W and Al, and the thickness of the supporting conductive substrate (1) is 50-400 um.

10. The vertical structure LED chip with double-sided transparent electrodes as claimed in claim 9, wherein the reflective metal layer (4) is any one of NiAg lamination and Al metal, and the epitaxial layer (6) is a luminescent GaN layer grown on a silicon-based or sapphire or SiC substrate.

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