Light emitting diode chip and preparation method thereof

Abstract

The invention provides a light emitting diode chip and a preparation method thereof, and belongs to the technical field of semiconductors. The light-emitting diode chip comprises an epitaxial layer, a silver mirror layer and a primary electrode, and the silver mirror layer and the primary electrode are sequentially stacked on one side of the epitaxial layer; the primary electrode comprises an ohmic contact part and a light reflecting part, the ohmic contact part is electrically connected with the light reflecting part, the ohmic contact part is electrically connected with the epitaxial layer, the light reflecting part covers one side of the silver mirror layer, and the orthographic projection area of the light reflecting part on the plane where the epitaxial layer is located is larger than that of the ohmic contact part on the plane where the epitaxial layer is located. The brightness of the light emitting diode chip can be improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a light emitting diode chip and a method for preparing the same. Background Art

[0002] A light emitting diode (LED) is a semiconductor diode that can convert electrical energy into light energy.

[0003] In the related art, the light-emitting diode chip is an important component of the light-emitting diode. The light-emitting diode chip mainly includes an epitaxial layer. In the flip-chip light-emitting diode chip, a silver mirror layer is also provided on one side of the epitaxial layer. The extremely high reflectivity of metal silver itself can effectively improve the brightness of the light-emitting diode chip. In addition, two primary electrodes are provided on the side of the silver mirror layer facing away from the epitaxial layer, namely, an N primary electrode and a P primary electrode, which are respectively used to realize the electrical connection between the N electrode and the N-type semiconductor layer of the epitaxial layer, and the electrical connection between the P electrode and the P-type semiconductor layer of the epitaxial layer.

[0004] However, the primary electrode is usually made of metal such as Cr, Ti, etc., which has a large light absorption, resulting in a low overall reflectivity of the primary electrode, which is not conducive to improving the brightness of the light-emitting diode chip. Summary of the invention

[0005] The embodiment of the present disclosure provides a light emitting diode chip and a method for manufacturing the same, which can improve the brightness of the light emitting diode chip. The technical solution is as follows:

[0006] On the one hand, an embodiment of the present disclosure provides a light-emitting diode chip, the light-emitting diode chip comprising an epitaxial layer, a silver mirror layer, and a primary electrode, wherein the silver mirror layer and the primary electrode are sequentially stacked on one side of the epitaxial layer;

[0007] The primary electrode includes an ohmic contact portion and a reflective portion, the ohmic contact portion is electrically connected to the reflective portion, the ohmic contact portion is electrically connected to the epitaxial layer, the reflective portion covers one side of the silver mirror layer, and an orthographic projection area of ​​the reflective portion on the plane where the epitaxial layer is located is greater than an orthographic projection area of ​​the ohmic contact portion on the plane where the epitaxial layer is located.

[0008] In one implementation of the present disclosure, the ohmic contact portion includes a first ohmic contact sub-portion and a second ohmic contact sub-portion;

[0009] The second ohmic contact sub-portion is stacked on a side of the first ohmic contact sub-portion facing away from the epitaxial layer;

[0010] The first ohmic contact sub-portion includes at least one metal of Cr and Ti, and the second ohmic contact sub-portion includes at least one metal of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0011] In another implementation of the present disclosure, the thickness of the first ohmic contact sub-portion is The thickness of the second ohmic contact portion is

[0012] In yet another implementation of the present disclosure, a radius of an orthographic projection of the ohmic contact portion on the plane where the epitaxial layer is located is 5-30 μm.

[0013] In yet another implementation of the present disclosure, the light reflecting portion includes a first light reflecting sub-portion and a second light reflecting sub-portion;

[0014] The second photoreflecting sub-portion is stacked on a side of the first photoreflecting sub-portion facing away from the epitaxial layer;

[0015] The first light reflecting sub-portion includes at least one metal of Ag and Al, and the second light reflecting sub-portion includes at least one metal of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0016] In another implementation of the present disclosure, the thickness of the first photoreflective sub-portion is The thickness of the second photoreflecting portion is

[0017] In yet another implementation of the present disclosure, the light emitting diode chip further includes a first insulating layer;

[0018] The first insulating layer covers the side of the silver mirror layer facing away from the epitaxial layer, and the first insulating layer is located between the silver mirror layer and the reflective portion. The first insulating layer is a SiO2 / Ti3O5 stacked structure, SiN x / SiO2 stacked structure, SiN x Either a single layer structure or a SiO2 single layer structure.

[0019] On the other hand, an embodiment of the present disclosure provides a method for preparing a light emitting diode chip, the method comprising:

[0020] growing an epitaxial layer;

[0021] preparing a silver mirror layer on one side of the epitaxial layer;

[0022] Preparing an ohmic contact portion on one side of the epitaxial layer so that the ohmic contact portion and the epitaxial layer are electrically connected;

[0023] A reflective portion is prepared on one side of the epitaxial layer so that the reflective portion covers one side of the silver mirror layer, and the reflective portion is electrically connected to the ohmic contact portion, and an orthographic projection area of ​​the reflective portion on the plane where the epitaxial layer is located is larger than an orthographic projection area of ​​the ohmic contact portion on the plane where the epitaxial layer is located.

[0024] In another implementation of the present disclosure, preparing an ohmic contact on one side of the epitaxial layer includes:

[0025] preparing a first ohmic contact sub-portion, wherein the first ohmic contact sub-portion comprises at least one metal of Cr and Ti;

[0026] A second ohmic contact sub-portion is prepared on a side of the first ohmic contact sub-portion facing away from the epitaxial layer, wherein the second ohmic contact sub-portion includes at least one metal selected from the group consisting of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0027] In one implementation of the present disclosure, preparing a reflective portion on one side of the epitaxial layer includes:

[0028] Prepare a first light-reflecting sub-portion, wherein the first light-reflecting sub-portion includes at least one metal selected from Ag and Al;

[0029] A second photoreflective sub-portion is prepared on a side of the first photoreflective sub-portion facing away from the epitaxial layer, wherein the second photoreflective sub-portion includes at least one metal selected from the group consisting of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0030] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0031] The light-emitting diode chip provided by the embodiment of the present disclosure includes an epitaxial layer, a silver mirror layer and a primary electrode. The epitaxial layer emits light after being energized, and the silver mirror layer can reflect the light and ensure its brightness, thereby realizing the light emission of the light-emitting diode chip. The primary electrode is located on the side of the silver mirror layer facing away from the epitaxial layer, and the primary electrode includes an ohmic contact portion and a reflective portion, the ohmic contact portion is electrically connected to the epitaxial layer, the ohmic contact portion is used to realize the ohmic contact between the primary electrode and the epitaxial layer, the reflective portion covers one side of the silver mirror layer, and the reflective portion is used to realize the reflection of the light generated by the epitaxial layer. In this way, the primary electrode can not only realize the ohmic contact, but also can cooperate with the silver mirror layer to reflect the light, thereby effectively improving the brightness of the light-emitting diode chip. In addition, the orthographic projection area of ​​the reflective portion on the plane where the epitaxial layer is located is greater than the orthographic projection area of ​​the ohmic contact portion on the plane where the epitaxial layer is located, so that the size of the ohmic contact portion is small, and then the degree of its light absorption is naturally small, which effectively reduces the influence of the ohmic contact portion on the brightness of the light-emitting diode chip.

[0032] That is to say, through the primary electrode, on the basis of ensuring ohmic contact, it plays a certain role in emitting light, effectively improving the brightness of the light-emitting diode chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 is a structural schematic diagram of a light-emitting diode chip provided by an embodiment of the present disclosure;

[0035] Figure 2 is a partial enlarged view of a primary electrode provided in an embodiment of the present disclosure;

[0036] Figure 3 is a flow chart of a method for preparing a light-emitting diode chip provided by an embodiment of the present disclosure;

[0037] Figure 4 It is a flow chart of another method for preparing a light emitting diode chip provided in an embodiment of the present disclosure.

[0038] The symbols in the figure mean the following:

[0039] 10. Epitaxial layer;

[0040] 110, first semiconductor layer; 120, active layer; 130, second semiconductor layer;

[0041] 20. Silver mirror layer;

[0042] 210. Transparent conductive layer;

[0043] 30. Primary electrode;

[0044] 310, ohmic contact portion; 311, first ohmic contact sub-portion; 312, second ohmic contact sub-portion; 320, light reflecting portion; 321, first light reflecting sub-portion; 322, second light reflecting sub-portion; 30a, first primary electrode; 30b, second primary electrode;

[0045] 40. a first insulating layer;

[0046] 50. substrate;

[0047] 60. Current blocking layer;

[0048] 70. Full-angle mirror layer;

[0049] 80a, first electrode; 80b, second electrode'

[0050] 90. Second insulating layer.

[0051] The above drawings show clear embodiments of the present disclosure, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present disclosure in any way, but to illustrate the concepts of the present disclosure to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0053] The embodiment of the present disclosure provides a light emitting diode chip, Figure 1 is a schematic diagram of the structure of the light emitting diode chip, see Figure 1 In this embodiment, the light emitting diode chip includes an epitaxial layer 10, a silver mirror layer 20, and a primary electrode 30, and the silver mirror layer 20 and the primary electrode 30 are sequentially stacked on one side of the epitaxial layer 10. The primary electrode 30 includes an ohmic contact portion 310 and a reflective portion 320, the ohmic contact portion 310 and the reflective portion 320 are electrically connected, the ohmic contact portion 310 and the epitaxial layer 10 are electrically connected, the reflective portion 320 covers one side of the silver mirror layer 20, and the orthographic projection area of ​​the reflective portion 320 on the plane where the epitaxial layer 10 is located is greater than the orthographic projection area of ​​the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located.

[0054] The light-emitting diode chip provided by the embodiment of the present disclosure includes an epitaxial layer 10, a silver mirror layer 20 and a primary electrode 30. The epitaxial layer 10 emits light after being energized, and the silver mirror layer 20 can reflect the light and ensure its brightness, thereby realizing the light emission of the light-emitting diode chip. The primary electrode 30 is located on the side of the silver mirror layer 20 facing away from the epitaxial layer 10. The primary electrode 30 includes an ohmic contact portion 310 and a reflective portion 320. The ohmic contact portion 310 is electrically connected to the epitaxial layer 10. The ohmic contact portion 310 is used to realize the ohmic contact between the primary electrode 30 and the epitaxial layer 10. The reflective portion 320 covers one side of the silver mirror layer 20. The reflective portion 320 is used to realize the reflection of the light generated by the epitaxial layer 10. In this way, the primary electrode 30 can not only realize the ohmic contact, but also cooperate with the silver mirror layer 20 to reflect the light, thereby effectively improving the brightness of the light-emitting diode chip. Moreover, the orthographic projection area of ​​the reflective portion 320 on the plane where the epitaxial layer 10 is located is larger than the orthographic projection area of ​​the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located, so that the size of the ohmic contact portion 310 is smaller, and the degree of its light absorption is naturally smaller, which effectively reduces the influence of the ohmic contact portion 310 on the brightness of the light-emitting diode chip.

[0055] That is to say, the primary electrode 30 plays a certain role in emitting light while ensuring ohmic contact, thereby effectively improving the brightness of the light emitting diode chip.

[0056] In this embodiment, the radius of the orthographic projection of the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located is 5-30 μm.

[0057] In the above implementation, the radius of the positive projection of the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located is designed to be within the above range. On the one hand, it can ensure the ohmic contact effect of the ohmic contact portion 310, and on the other hand, it can avoid large light absorption due to the excessive size of the ohmic contact portion 310, which is not conducive to improving the brightness of the light-emitting diode chip.

[0058] Continue to see Figure 1 In this embodiment, the epitaxial layer 10 includes a first semiconductor layer 110, an active layer 120, and a second semiconductor layer 130 stacked in sequence. The first semiconductor layer 110 is of a first conductivity type, and the second semiconductor layer 130 is of a second conductivity type, and the second conductivity type is different from the first conductivity type.

[0059] When the light emitting diode chip is working, electron transition occurs between the first semiconductor layer 110 and the second semiconductor layer 130 , and the active layer 120 emits light.

[0060] In this embodiment, the first semiconductor layer 110 is an N-type gallium nitride layer, the active layer 120 is a quantum well layer, and the second semiconductor layer 130 is a P-type gallium nitride layer. Of course, in other embodiments, the first semiconductor layer 110 may also be a P-type gallium nitride layer, the second semiconductor layer 130 may be an N-type gallium nitride layer, and the active layer 120 may be a quantum well layer, and the present disclosure is not limited thereto.

[0061] Continue to see Figure 1 In this embodiment, there are two types of primary electrodes 30, one is a first primary electrode 30a for realizing ohmic contact of the first semiconductor layer 110, and the other is a second primary electrode 30b for realizing ohmic contact of the second semiconductor layer 130. The two types of primary electrodes 30 have basically the same structure, and the difference mainly lies in the shape and position. The structure of the primary electrode 30 is first introduced below.

[0062] Figure 2 is a partial enlarged view of the primary electrode 30, combined with Figure 2In this embodiment, the ohmic contact portion 310 includes a first ohmic contact sub-portion 311 and a second ohmic contact sub-portion 312. The second ohmic contact sub-portion 312 is stacked on the side of the first ohmic contact sub-portion 311 facing away from the epitaxial layer 10, the first ohmic contact sub-portion 311 includes at least one metal of Cr and Ti, and the second ohmic contact sub-portion 312 includes at least one metal of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0063] In the above implementation, the first ohmic contact sub-portion 311 is in ohmic contact with the epitaxial layer 10, and the first ohmic contact sub-portion 311 includes at least one metal of Cr and Ti. The ohmic contact performance can be ensured by utilizing the characteristics of the above metals. The second ohmic contact sub-portion 312 is the portion of the ohmic contact portion 310 other than the first ohmic contact sub-portion 311. Since it is stacked on the side of the first ohmic contact sub-portion 311 facing away from the epitaxial layer 10, it does not directly form an ohmic contact with the epitaxial layer 10. It does not need to include at least one metal of Cr and Ti like the first ohmic contact sub-portion 311, but only includes at least one metal of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu, which is beneficial to reduce the overall light absorption of the ohmic contact portion 310.

[0064] Exemplarily, the thickness of the first ohmic contact sub-portion 311 is The thickness of the second ohmic contact sub-portion 312 is

[0065] In the above implementation, the thickness of the first ohmic contact sub-portion 311 and the second ohmic contact sub-portion 310 are both dimensions in the epitaxial growth direction. The thickness of the first ohmic contact sub-portion 311 is much smaller than the thickness of the second ohmic contact sub-portion 312, so that the ohmic contact sub-portion 310 requires less Cr and Ti metals, thereby avoiding light absorption caused by Cr and Ti metals, which is beneficial to improving the brightness of the light-emitting diode chip.

[0066] Continue to see Figure 2 In this embodiment, the light reflecting portion 320 includes a first light reflecting sub-portion 321 and a second light reflecting sub-portion 322. The second light reflecting sub-portion 322 is stacked on the side of the first light reflecting sub-portion 321 facing away from the epitaxial layer 10, the first light reflecting sub-portion 321 includes at least one metal selected from Ag and Al, and the second light reflecting sub-portion 322 includes at least one metal selected from Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0067] In the above implementation, the first photoreflective sub-portion 321 directly faces the direction of the epitaxial layer 10, that is, directly faces the direction of the light, and plays a role in reflecting the light. The first photoreflective sub-portion 321 includes at least one metal selected from Ag and Al. By utilizing the characteristics of the above metals, it is possible to ensure that the first photoreflective sub-portion 321 has a high reflectivity. The second photoreflective sub-portion 322 is the portion of the reflective portion 320 other than the first photoreflective sub-portion 321. Since it is stacked on the side of the first photoreflective sub-portion 321 facing away from the epitaxial layer 10, it does not directly face the epitaxial layer 10. It does not need to include at least one metal selected from Ag and Al like the first photoreflective sub-portion 321, but only at least one metal selected from Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu, which is beneficial to improving the conductive performance and structural strength of the reflective portion 320.

[0068] Exemplarily, the thickness of the first light-reflecting sub-portion 321 is The thickness of the second photoreflecting sub-portion 322 is

[0069] In the above implementation, the thickness of the first reflective sub-portion 321 and the second reflective sub-portion 322 are both dimensions in the epitaxial growth direction. The thickness of the first reflective sub-portion 321 is much smaller than the thickness of the second reflective sub-portion 322, so that the reflective portion 320 requires less Ag and Al metals, thereby improving the conductive performance of the reflective portion 320 on the one hand, and improving the structural strength of the reflective portion 320 on the other hand.

[0070] See again Figure 1 In this embodiment, the light emitting diode chip further includes a transparent conductive layer 210 , which covers one side of the epitaxial layer 10 , and the transparent conductive layer 210 is located between the epitaxial layer 10 and the silver mirror layer 20 .

[0071] The transparent conductive layer 210 is transparent and conductive. When the epitaxial layer 10 emits light, the light can pass through the transparent conductive layer 210 smoothly without being absorbed or scattered, thereby improving the light extraction efficiency of the light emitting diode chip and further improving the light emitting brightness of the light emitting diode chip. At the same time, the transparent conductive layer 210 is conductive and can provide current for the epitaxial layer 10.

[0072] Exemplarily, the transparent conductive layer 210 is an indium tin oxide ITO layer, and the transparent conductive layer 210 is formed by sputtering on the epitaxial layer 10 using magnetron sputtering technology. ITO has both optical transparency and high conductivity. When the epitaxial layer 10 emits light, the light can pass through the transparent conductive layer 210 smoothly. The high conductivity ensures that the current can be effectively transferred to the epitaxial layer 10, thereby improving the luminous efficiency of the light-emitting diode chip.

[0073] Continue to see Figure 1In this embodiment, the light-emitting diode chip further includes a first insulating layer 40, the first insulating layer 40 covers the side of the silver mirror layer 20 facing away from the epitaxial layer 10, and the first insulating layer 40 is located between the silver mirror layer 20 and the reflective portion 320, and the first insulating layer 40 is a SiO2 / Ti3O5 stacked structure, SiN x / SiO2 stacked structure, SiN x Either a single layer structure or a SiO2 single layer structure.

[0074] In the above implementation, the first insulating layer 40 covers the side of the silver mirror layer 20 facing away from the epitaxial layer 10, which can protect the silver mirror layer 20. x The SiO2 / SiO2 stacked structure has a high reflectivity and can cooperate with the silver mirror layer 20 to reflect the light generated by the epitaxial layer 10, thereby effectively improving the brightness of the light emitting diode chip.

[0075] Exemplarily, the first insulating layer 40 is a DBR structure layer, which can further improve the reflectivity of the first insulating layer 40 and is beneficial to improving the brightness of the light emitting diode chip.

[0076] Continue to see Figure 1 In this embodiment, the light emitting diode chip further includes a substrate 50 , which provides a basis for the growth of the epitaxial layer 10 .

[0077] Exemplarily, the substrate 50 is a sapphire substrate, a silicon wafer substrate, or other light emitting diode chip substrate materials.

[0078] Of course, in other embodiments, the light emitting diode chip may not have the substrate 50 , and the present disclosure does not limit this.

[0079] In this embodiment, the light-emitting diode chip further includes a current blocking layer 60 and a full-angle reflector layer 70 stacked in sequence. The current blocking layer 60 is a CBL layer, and the full-angle reflector layer 70 is an ODR layer. The current blocking layer 60 and the full-angle reflector layer 70 are respectively located on one side of the epitaxial layer 10 and between the epitaxial layer 10 and the first insulating layer 40.

[0080] In this embodiment, the light emitting diode chip further includes a first electrode 80 a , a second electrode 80 b and a second insulating layer 90 .

[0081] The second insulating layer 90 covers the primary electrode 30 , the first electrode 80 a passes through the second insulating layer 90 to connect with the first primary electrode 30 a , and the second electrode 80 b passes through the second insulating layer 90 to connect with the second primary electrode 30 b .

[0082] Exemplarily, the material of the first electrode 80a and the second electrode 80b is one or a combination of metals such as Cr, Al, AlCu, Ti, Ni, Pt, Au, AuSn, etc. The first electrode 80a and the second electrode 80b have the same thickness.

[0083] Exemplarily, the second insulating layer 90 is a DBR layer or a SiO2 layer, wherein the DBR layer is a stacked layer formed by SiO2 and Ti3O5.

[0084] The light-emitting diode chip in the related art was used as a control group, and the light-emitting diode provided by the embodiment of the present disclosure was used as an experimental group. Control experiments were carried out respectively, and the following Table 1 was obtained.

[0085]

[0086] Table 1

[0087] As shown in Table 1, the light emitting diode chip provided in the embodiment of the present disclosure has an optical power increased by 1.73% compared with the light emitting diode in the related art, indicating that the brightness of the light emitting diode chip can be improved.

[0088] Figure 3 is a flow chart of a method for preparing a light emitting diode chip provided by an embodiment of the present disclosure, for preparing Figure 1 The light emitting diode chip shown in this embodiment is prepared by a method comprising:

[0089] Step 301 : growing an epitaxial layer 10 .

[0090] Step 302 : preparing a silver mirror layer 20 on one side of the epitaxial layer 10 .

[0091] Step 303 : preparing an ohmic contact portion 310 on one side of the epitaxial layer 10 , so that the ohmic contact portion 310 and the epitaxial layer 10 are electrically connected.

[0092] Step 304: Prepare a reflective portion 320 on one side of the epitaxial layer 10 so that the reflective portion 320 covers one side of the silver mirror layer 20, and the reflective portion 320 is electrically connected to the ohmic contact portion 310, and the orthographic projection area of ​​the reflective portion 320 on the plane where the epitaxial layer 10 is located is larger than the orthographic projection area of ​​the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located.

[0093] The primary electrode 30 is prepared through steps 303 and 304 .

[0094] The light-emitting diode chip prepared by the preparation method provided by the embodiment of the present disclosure includes an epitaxial layer 10, a silver mirror layer 20 and a primary electrode 30. Among them, the epitaxial layer 10 emits light after being energized, and the silver mirror layer 20 can reflect the light and ensure its brightness, thereby realizing the light emission of the light-emitting diode chip. The primary electrode 30 is located on the side of the silver mirror layer 20 facing away from the epitaxial layer 10, and the primary electrode 30 includes an ohmic contact portion 310 and a reflective portion 320, the ohmic contact portion 310 is electrically connected to the epitaxial layer 10, and the ohmic contact portion 310 is used to realize the ohmic contact between the primary electrode 30 and the epitaxial layer 10, and the reflective portion 320 covers one side of the silver mirror layer 20, and the reflective portion 320 is used to realize the reflection of the light generated by the epitaxial layer 10. In this way, the primary electrode 30 can not only realize the ohmic contact, but also can cooperate with the silver mirror layer 20 to reflect the light, thereby effectively improving the brightness of the light-emitting diode chip. Moreover, the orthographic projection area of ​​the reflective portion 320 on the plane where the epitaxial layer 10 is located is larger than the orthographic projection area of ​​the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located, so that the size of the ohmic contact portion 310 is smaller, and the degree of its light absorption is naturally smaller, which effectively reduces the influence of the ohmic contact portion 310 on the brightness of the light-emitting diode chip.

[0095] That is to say, the primary electrode 30 plays a certain role in emitting light while ensuring ohmic contact, thereby effectively improving the brightness of the light emitting diode chip.

[0096] Figure 4 is a flow chart of another method for preparing a light emitting diode chip provided by an embodiment of the present disclosure, for preparing Figure 1 The light emitting diode chip shown in this embodiment is prepared by a method comprising:

[0097] Step 401: Provide a substrate.

[0098] Exemplarily, the substrate is a sapphire substrate, a silicon wafer substrate, or other light emitting diode chip substrate materials.

[0099] Step 402 : growing an epitaxial layer 10 .

[0100] Exemplarily, a metal-organic chemical vapor deposition technique Metal-organic Chemical Vapor Deposition (MOCVD) is used to sequentially grow the first semiconductor layer 110, the active layer 120, and the second semiconductor layer 130. The first semiconductor layer 110 has a first conductivity type, and the second semiconductor layer 130 has a second conductivity type different from the first conductivity type. Energy transition occurs between the first semiconductor layer 110 and the second semiconductor layer 130, and the active layer 120 emits light.

[0101] Exemplarily, the first semiconductor layer 110 is an N-type gallium nitride layer, the active layer 120 is a quantum well layer, and the second semiconductor layer 130 is a P-type gallium nitride layer.

[0102] Step 403 : growing a transparent conductive layer 210 on one side of the epitaxial layer 10 .

[0103] Exemplarily, a layer of indium tin oxide (ITO) film is deposited on the epitaxial layer 10 by magnetron sputtering technology or electron beam evaporation process, and a part of the ITO film is removed by photolithography and chemical wet etching process to form the transparent conductive layer 210 .

[0104] Step 404 : sequentially prepare a current blocking layer 60 and a full-angle reflector layer 70 on one side of the transparent conductive layer 210 .

[0105] Step 405 : preparing a silver mirror layer 20 on one side of the full-angle reflective mirror layer 70 .

[0106] Exemplarily, the silver mirror layer 20 is sputtered on the full-angle reflector layer 70 by magnetron sputtering technology or electron beam evaporation process, and the material is one or a combination of multiple materials such as Ag, Ni, Ti, and TiW.

[0107] Step 406 : preparing an ohmic contact portion 310 on one side of the silver mirror layer 20 , so that the ohmic contact portion 310 and the epitaxial layer 10 are electrically connected.

[0108] Exemplarily, step 406 includes the following steps:

[0109] First, the first ohmic contact sub-portion 311 is prepared. The first ohmic contact sub-portion 311 includes at least one metal of Cr and Ti.

[0110] Then, a second ohmic contact sub-portion 312 is prepared on the side of the first ohmic contact sub-portion 311 facing away from the epitaxial layer 10 , and the second ohmic contact sub-portion 312 includes at least one metal selected from Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0111] Step 407 : preparing a first insulating layer 40 on one side of the ohmic contact portion 310 , and etching a first through hole and a second through hole in the first insulating layer 40 .

[0112] Exemplarily, the first insulating layer 40 covers the side of the silver mirror layer 20 facing away from the epitaxial layer 10, and the first insulating layer 40 is located between the silver mirror layer 20 and the reflective portion 320, and the first insulating layer 40 is a SiO2 / Ti3O5 stacked structure, or the first insulating layer 40 is a SiN x / SiO2 stacked structure.

[0113] Step 408: preparing a reflective portion 320 on one side of the first insulating layer 40 so that the reflective portion 320 covers one side of the silver mirror layer 20, and the reflective portion 320 is electrically connected to the ohmic contact portion 310 through the first through hole and the second through hole respectively.

[0114] Exemplarily, the orthographic projection area of ​​the light reflecting portion 320 on the plane where the epitaxial layer 10 is located is greater than the orthographic projection area of ​​the ohmic contact portion 310 on the plane where the epitaxial layer 10 is located.

[0115] Exemplarily, step 408 includes the following steps:

[0116] First, the first light reflecting sub-portion 321 is prepared. The first light reflecting sub-portion 321 includes at least one metal of Ag and Al.

[0117] Then, a second photoreflective sub-portion 322 is prepared on the side of the first photoreflective sub-portion 321 facing away from the epitaxial layer 10 , and the second photoreflective sub-portion 322 includes at least one metal selected from Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

[0118] The primary electrode 30 is prepared through step 406 and step 408 .

[0119] Step 409 : preparing a second insulating layer 90 , and etching a third through hole and a fourth through hole in the second insulating layer 90 .

[0120] Step 410: Prepare a first electrode 80a to pass through the third through hole to connect with the first primary electrode 30a, and prepare a second electrode 80b to pass through the fourth through hole to connect with the second primary electrode 30b.

[0121] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0122] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A light emitting diode chip, characterized in that: It comprises an epitaxial layer (10), a silver mirror layer (20), and a primary electrode (30), wherein the silver mirror layer (20) and the primary electrode (30) are sequentially stacked on one side of the epitaxial layer (10); The primary electrode (30) comprises an ohmic contact portion (310) and a reflective portion (320), the ohmic contact portion (310) and the reflective portion (320) being electrically connected, the ohmic contact portion (310) and the epitaxial layer (10) being electrically connected, the reflective portion (320) covering one side of the silver mirror layer (20), and an orthographic projection area of ​​the reflective portion (320) on the plane where the epitaxial layer (10) is located being larger than an orthographic projection area of ​​the ohmic contact portion (310) on the plane where the epitaxial layer (10) is located.

2. The light emitting diode chip according to claim 1, characterized in that: The ohmic contact portion (310) comprises a first ohmic contact sub-portion (311) and a second ohmic contact sub-portion (312); The second ohmic contact sub-portion (312) is stacked on a side of the first ohmic contact sub-portion (311) facing away from the epitaxial layer (10); The first ohmic contact sub-portion (311) includes at least one metal selected from Cr and Ti, and the second ohmic contact sub-portion (312) includes at least one metal selected from Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

3. The light emitting diode chip according to claim 2, characterized in that: The thickness of the first ohmic contact sub-portion (311) is The thickness of the second ohmic contact sub-portion (312) is 4. The light emitting diode chip according to claim 1, characterized in that: The radius of the orthographic projection of the ohmic contact portion (310) on the plane where the epitaxial layer (10) is located is 5-30 μm.

5. The light emitting diode chip according to claim 1, characterized in that: The light reflecting portion (320) comprises a first light reflecting sub-portion (321) and a second light reflecting sub-portion (322); The second photoreflecting sub-portion (322) is stacked on a side of the first photoreflecting sub-portion (321) facing away from the epitaxial layer (10); The first light-reflecting sub-portion (321) includes at least one metal selected from Ag and Al, and the second light-reflecting sub-portion (322) includes at least one metal selected from Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

6. The light emitting diode chip according to claim 5, characterized in that: The thickness of the first light-reflecting sub-portion (321) is The thickness of the second photoreflecting sub-portion (322) is 7. The light emitting diode chip according to claim 1, characterized in that: The light-emitting diode chip further comprises a first insulating layer (40); The first insulating layer (40) covers the side of the silver mirror layer (20) facing away from the epitaxial layer (10), and the first insulating layer (40) is located between the silver mirror layer (20) and the reflective portion (320), and the first insulating layer (40) is a SiO2 / Ti3O5 stacked structure, SiN x / SiO2 stacked structure, SiN x Either a single layer structure or a SiO2 single layer structure.

8. A method for preparing a light emitting diode chip, characterized in that: include: growing an epitaxial layer (10); Preparing a silver mirror layer (20) on one side of the epitaxial layer (10); An ohmic contact portion (310) is prepared on one side of the epitaxial layer (10) so that the ohmic contact portion (310) and the epitaxial layer (10) are electrically connected; A reflective portion (320) is prepared on one side of the epitaxial layer (10) so that the reflective portion (320) covers one side of the silver mirror layer (20), and the reflective portion (320) is electrically connected to the ohmic contact portion (310), and the orthographic projection area of ​​the reflective portion (320) on the plane where the epitaxial layer (10) is located is greater than the orthographic projection area of ​​the ohmic contact portion (310) on the plane where the epitaxial layer (10) is located.

9. The preparation method according to claim 8, characterized in that: An ohmic contact portion (310) is prepared on one side of the epitaxial layer (10), comprising: Prepare a first ohmic contact sub-portion (311), wherein the first ohmic contact sub-portion (311) includes at least one metal selected from the group consisting of Cr and Ti; A second ohmic contact sub-portion (312) is prepared on the side of the first ohmic contact sub-portion (311) facing away from the epitaxial layer (10), and the second ohmic contact sub-portion (312) includes at least one metal selected from the group consisting of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

10. The preparation method according to claim 8, characterized in that: A reflective portion (320) is prepared on one side of the epitaxial layer (10), comprising: Prepare a first light-reflecting sub-portion (321), wherein the first light-reflecting sub-portion (321) comprises at least one metal selected from Ag and Al; A second photoreflective sub-portion (322) is prepared on the side of the first photoreflective sub-portion (321) facing away from the epitaxial layer (10), wherein the second photoreflective sub-portion (322) comprises at least one metal selected from the group consisting of Cr, Al, AlCu, Ti, Ni, Pt, Au, and Cu.

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