Flip-chip light emitting element and light emitting device

Abstract

The application provides a flip light-emitting element and a light-emitting device, which are formed with a first contact electrode electrically connected with a semiconductor layer of a first conductive type and a second contact electrode electrically connected with a semiconductor layer of a second conductive type, wherein the second contact electrode is distributed in an array, preferably on at least one concentric circle with the first contact electrode as the center. The current can be electrically connected with the P-type epitaxial layer through the first contact electrode (P-contact electrode) and be uniformly dispersed by the P-type epitaxial layer, effectively improving the problem of uneven current expansion, so that the current uniformly expands to the P-type epitaxial layer. In addition, the dot-matrix P / N contact electrode design can reduce the waste of the effective light-emitting area caused by the first contact electrode on one hand, and reduce the ohmic contact interface area between the contact electrode and the epitaxial layer on the other hand, effectively improve the current expansion capacity, and improve the light-emitting efficiency of the chip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor devices and apparatuses, and in particular to a flip-chip light-emitting element and a light-emitting apparatus. BACKGROUND

[0002] For a large-size flip-chip light-emitting element, the main problem limiting its application is current spreading. Due to the chip structure of the flip-chip or horizontal light-emitting element, the main current spreading layer is the epitaxial layer, and under large-current driving, the chip light emission is mainly concentrated near the metal electrode, the current spreading is uneven, and the light-emitting efficiency is low.

[0003] In addition, for a flip-chip LED chip, the light-emitting surface is on the substrate side away from the pad electrode, in order to improve the light-emitting efficiency, a DBR or a pad electrode with certain reflection effect is usually arranged on the side away from the substrate, but the DBR can only have high reflectivity for light of a specific wavelength and a specific angle, and the reflection effect has limitations. At the same time, there is a gap area between the pad electrodes, so the reflection effect also has limitations. The above will make the light-emitting efficiency of the LED chip low.

[0004] In view of the above, it is necessary to provide a scheme capable of effectively improving the light-emitting efficiency of a flip-chip LED chip. SUMMARY

[0005] In view of the above-mentioned defects of the flip-chip LED chip in the prior art, the present application provides a flip-chip light-emitting element and a light-emitting apparatus to solve one or more of the above problems.

[0006] An embodiment of the present application provides a flip-chip light-emitting element, which comprises:

[0007] a transparent substrate;

[0008] an epitaxial structure formed on the transparent substrate, the epitaxial structure comprising, from bottom to top, a semiconductor layer of a first conductivity type, an active layer, and a semiconductor layer of a second conductivity type;

[0009] a transparent dielectric layer formed on a surface of the epitaxial structure, the transparent dielectric layer having a first contact electrode electrically connected to the semiconductor layer of the first conductivity type and a second contact electrode electrically connected to the semiconductor layer of the second conductivity type;

[0010] a metal reflection layer formed above the transparent dielectric layer;

[0011] a first insulating protective layer formed on a surface of the metal reflection layer and a sidewall of the epitaxial structure;

[0012] a pad region above the first insulating protective layer, the pad region being formed with a first pad electrically connected to the semiconductor layer of the first conductive type and a second pad electrically connected to the semiconductor layer of the second conductive type;

[0013] wherein the first contact electrodes and the second contact electrodes are distributed in an array, and in the region corresponding to the first pad, the second contact electrodes are distributed on at least one concentric ring with the first contact electrodes as the center.

[0014] Optionally, in the region corresponding to the second pad, the first contact electrodes are formed as a plurality of finger-shaped portions, and the second contact electrodes are distributed in an array between the finger-shaped portions, the finger-shaped portions being connected to the first contact electrodes in the region corresponding to the first pad.

[0015] Optionally, a first via hole is formed in the region corresponding to the first pad, the first via hole penetrating the transparent dielectric layer and the first insulating protective layer, and the first pad is electrically connected to the first contact electrodes through the first via hole;

[0016] a second via hole is formed in the region corresponding to the second pad, the second via hole penetrating the first insulating protective layer, and the second pad is electrically connected to the metal reflective layer through the second via hole.

[0017] Optionally, the metal reflective layer is an Ag mirror reflective layer.

[0018] Optionally, in the region corresponding to the second pad, the second contact electrodes are also distributed on a plurality of concentric rings with the first contact electrodes as the center.

[0019] Optionally, the flip-chip light-emitting element further comprises:

[0020] a metal layer above the first insulating protective layer, the metal layer being distributed in a mesh shape to be electrically connected to the first contact electrodes;

[0021] a second insulating protective layer above the metal layer, and the pad region is above the second insulating protective layer, wherein

[0022] a conductive column is formed at a position corresponding to the first contact electrodes, the conductive column penetrating the transparent dielectric layer and the first insulating protective layer, and being electrically connected to the metal layer and the first contact electrodes, and the region corresponding to the first pad is formed with a third via hole penetrating the second insulating protective layer, and the first pad is electrically connected to the metal layer through the third via hole;

[0023] The second pad is electrically connected with the metal reflecting layer through a fourth through hole formed in a region corresponding to the second pad, the fourth through hole penetrating the second insulating protective layer and the first insulating protective layer.

[0024] Optionally, the flip light emitting element further comprises a transparent conductive adhesive layer between the transparent dielectric layer and the metal reflecting layer, the transparent conductive adhesive layer being distributed in a dot pattern.

[0025] Optionally, the transparent conductive adhesive layer is a dot patterned transparent ITO layer.

[0026] Optionally, the light emitting element is a red or infrared light emitting element.

[0027] Optionally, the flip light emitting element further comprises a transparent bonding layer, the epitaxial structure being bonded to the transparent substrate through the transparent bonding layer.

[0028] Optionally, the flip light emitting element further comprises a metal adhesive layer between the metal reflecting layer and the first insulating protective layer.

[0029] According to another embodiment of the present application, a light emitting device is provided, comprising a circuit substrate and a light emitting element on the circuit substrate, the light emitting element being the flip light emitting element provided by the present application.

[0030] As described above, the flip light emitting element and the light emitting device of the present application have the following beneficial effects:

[0031] The flip light emitting element of the present application is formed with a first contact electrode electrically connected with a first conductive type semiconductor layer and a second contact electrode electrically connected with a second conductive type semiconductor layer, wherein the second contact electrode is distributed in an array, preferably on at least one concentric circle with the first contact electrode as the center. The current can be electrically connected with the P-type epitaxial layer through the first contact electrode (P-contact electrode) and be evenly dispersed by the P-type epitaxial layer, effectively improving the problem of uneven current expansion, so that the current is evenly expanded to the P-type epitaxial layer. In addition, the dot array P / N contact electrode design can reduce the waste of effective light emitting area caused by the arrangement of the P-contact electrode on the one hand, and reduce the ohmic contact interface area of the contact electrode and the epitaxial layer on the other hand, effectively improve the current expansion ability, and improve the light emitting efficiency of the chip.

[0032] The light emitting element of the present application is provided with a transparent conductive adhesive layer with a certain density of uniform point structure between the metal reflecting layer and the transparent dielectric layer, which can enhance the adhesion of the metal reflecting layer and the transparent dielectric layer, and the point structure of the transparent conductive adhesive layer improves the light emitting efficiency of the chip. In addition, a metal adhesive layer can be provided between the metal reflecting layer and the first insulating protective layer, which can enhance the adhesion of the metal reflecting layer and the first insulating protective layer, and also can protect the metal reflecting layer from oxidation. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A top view of the flip chip light emitting element according to the first embodiment of the present application.

[0034] Figure 2 A cross-sectional view of the flip chip light emitting element according to the first embodiment of the present application along line A-A. Figure 1

[0035] Figure 3 A cross-sectional view of the flip chip light emitting element according to the first embodiment of the present application along line B-B. Figure 1

[0036] Figure 4 A flow chart of the manufacturing method of the flip chip light emitting element according to the first embodiment of the present application. Figure 1

[0037] Figure 5 A schematic view of growing the epitaxial structure on the growth substrate.

[0038] Figure 6 A schematic view of bonding the epitaxial structure with the transparent substrate.

[0039] Figure 7 A cross-sectional view of the flip chip light emitting element according to the first embodiment of the present application along line A-A. Figure 1

[0040] Figure 8 A cross-sectional view of the flip chip light emitting element according to the first embodiment of the present application along line B-B. Figure 1

[0041] Figure 9 A schematic view of forming the second contact electrode on the epitaxial structure.

[0042] Figure 10 A schematic view of forming the metal reflecting layer on the first and second contact electrodes.

[0043] Figure 11 A schematic view of forming the first and second through holes on the epitaxial structure.

[0044] ​​​​​Figure 12 A top view of the flip-chip light emitting device according to Embodiment 2 of the present application is shown.

[0045] Figure 13 A cross-sectional structure along the line C-C is shown. Figure 12

[0046] Figure 14 A cross-sectional structure along the line D-D is shown. Figure 12

[0047] Figure 15 A structure in which a first contact electrode is formed on the epitaxial structure is shown.

[0048] Figure 16 A structure in which a second contact electrode is formed on the epitaxial structure is shown.

[0049] Figure 17 A structure in which a metal reflective layer is formed on the epitaxial structure is shown.

[0050] Figure 18 A structure in which a metal layer is formed on the epitaxial structure is shown.

[0051] Figure 19 A structure in which a second insulating protective layer is formed on the epitaxial structure is shown.

[0052] Figure 20 A structure of the flip-chip light emitting device according to Embodiment 3 of the present application is shown.

[0053] Figure 21 A structure of the flip-chip light emitting device according to Embodiment 4 of the present application is shown.

[0054] Explanation of element reference numerals

[0055] ​​001, growth substrate; 002, concentric circles; 100 (100'), flip-chip light-emitting element; 101, transparent substrate; 102, bonding layer; 103, epitaxial structure; 1031, semiconductor layer of the first conductivity type; 1032, active layer; 1033, semiconductor layer of the second conductivity type; 104, transparent dielectric layer; 1050, first mesa; 1050', trench; 1051, first contact electrode; 1052, second contact electrode; 1053, finger portion; 1054, second mesa; 10 6, metal reflective layer; 1060, first opening; 107, first insulating protective layer; 1070, first through hole; 1072, second through hole; 1071, conductive column; 1081, first solder pad; 1082, second solder pad; 109, metal layer; 1090, second opening; 110, second insulating protective layer; 1101, third through hole; 1102, fourth through hole; 120, transparent conductive adhesion layer; 130, metal adhesion layer; 200, light-emitting device; 201, circuit substrate; 202, light-emitting unit. DETAILED DESCRIPTION

[0056] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0057] The flip-chip light-emitting element and the light-emitting device provided by the present application are now described in detail with reference to the following embodiments and drawings.

[0058] Example 1

[0059] This embodiment provides a flip-chip light-emitting element, such as Figures 1 to 3 As shown, the flip-chip light-emitting element 100 of this embodiment includes: a transparent substrate 101, an epitaxial structure 103 formed on the transparent substrate 101, a transparent dielectric layer 104 formed on the surface of the epitaxial structure 103, and a metal reflective layer 106 formed above the transparent dielectric layer 104; a first insulating protective layer 107 formed on the surface of the metal reflective layer 106 and on the sidewalls of the epitaxial structure 103; and a pad area located above the first insulating protective layer 107, the pad area being formed with a first pad 1081 electrically connected to the first conductive type semiconductor layer 1031, and a second pad 1082 electrically connected to the second conductive type semiconductor layer 1033.

[0060] Reference Figure 2 and Figure 3As shown, in this embodiment, the epitaxial structure 103 includes a first conductivity type semiconductor layer 1031, an active layer 1032, and a second conductivity type semiconductor layer 1033 stacked in sequence from the transparent substrate 101. In this embodiment, the epitaxial structure 103 is preferably a red light epitaxial structure 103 of the AlGaInP quaternary system.

[0061] The transparent dielectric layer 104 is formed on the top and sidewalls of the epitaxial structure 103. Figure 3 As shown, a first contact electrode 1051 and a second contact electrode 1052 are formed in the transparent dielectric layer 104, wherein the first contact electrode 1051 is electrically connected to the first conductive type semiconductor layer 1031, and the second contact electrode 1052 is electrically connected to the second conductive type semiconductor layer 1033. The first contact electrode 1051 is formed on a first mesa 1050 (refer to FIG. 1 ) that penetrates the second conductive type semiconductor layer 1033 and the active layer 1032 and exposes the first conductive type semiconductor layer 1031. Figure 7 The second contact electrode 1052 is formed in an opening penetrating the transparent dielectric layer 104 and exposing the second conductive type semiconductor layer 1033 .

[0062] like Figure 1 As shown, the first contact electrode 1051 and the second contact electrode 1052 are distributed in an array, and in the area corresponding to the first pad 1081, the second contact electrode 1052 is distributed on at least one concentric circle 002 with the first contact electrode 1051 as the center. The array distribution of the first contact electrode 1051 can, on the one hand, reduce the waste of effective light-emitting area caused by setting the contact electrode of the P-type semiconductor layer; on the other hand, it can reduce the area of ​​the contact interface between the first contact electrode 1051 and the first conductive type semiconductor layer 1031, thereby effectively improving the current expansion capability, thereby improving the light-emitting efficiency of the chip. Figure 1 and 2 As shown in the area corresponding to the second pad 1082, the first contact electrode 1051 is formed as a finger portion 1053, which extends from the first pad 1081 to the second pad 1082 and is connected to the first contact electrode 1051 in the area corresponding to the first pad 1081. Figure 1 As shown, the finger portion 1053 is connected to the first contact electrode 1051 in the area closest to the first pad 1081 , thereby further reducing the waste of the effective light-emitting area caused by the provision of the first contact electrode 1051 of the P-type semiconductor layer.

[0063] Likewise Figure 3As shown, the metal reflective layer 106 is formed above the transparent dielectric layer 104, and the metal reflective layer 106 is electrically connected with the second contact electrode 1052. Meanwhile, the first insulating protective layer 107 is formed above the metal reflective layer 106. Preferably, the first insulating protective layer 107 is also formed on the sidewall of the epitaxial structure 103. Above the first contact electrode 1051, the metal reflective layer 106 forms a first opening 1060, and the first insulating protective layer 107 is filled in the first opening 1060 to insulate the first pad 1081 electrically connected with the first ohmic contact.

[0064] The first insulating protective layer 107 is formed above the metal reflective layer 106, the exposed transparent dielectric layer 104, and the sidewall of the metal reflective layer 106 and the transparent dielectric layer 104, and meanwhile fills the first opening 1060 of the metal reflective layer 106 to further protect the epitaxial structure 103 of the light emitting element. As shown, Figure 3 As shown, in the area corresponding to the first pad 1081, preferably, in the position corresponding to the first opening 1060, a first via hole 1070 is formed through the first insulating protective layer 107 and the transparent dielectric layer 104, and the first via hole 1070 exposes the first contact electrode 1051. In the area corresponding to the second pad 1082, a second via hole 1072 is formed through the first insulating protective layer, and the second via hole 1072 exposes the metal reflective layer 106. As shown, Figure 1 As shown, the first pad 1081 is formed above the first insulating protective layer, and meanwhile fills the first via hole 1070 to be connected with the first contact electrode 1051, and further to be electrically connected with the first conductive type semiconductor layer 1031. The second pad 1082 is formed above the first insulating protective layer 107, and meanwhile fills the second via hole 1072 to be electrically connected with the metal reflective layer 106. Since the metal reflective layer 106 is electrically connected with the second contact electrode 1052 in the transparent dielectric layer 104, the electrical connection between the second pad 1082 and the second conductive type semiconductor layer 1033 is realized.

[0065] As shown, Figure 2 and 3 As shown, the bonding layer 102 is further included between the epitaxial structure 103 and the transparent substrate 101, and the bonding layer 102 bonds the epitaxial structure 103 to the transparent substrate 101. Preferably, the side of the bonding layer 102 bonded with the epitaxial structure 103 is formed as a roughened surface.

[0066] The embodiment also provides a manufacturing method of the flip light emitting element 100, as shown, Figure 4 The method comprises:

[0067] S101: growing an epitaxial structure;

[0068] As shown, Figure 5As shown, a second conductivity type semiconductor layer 1033, an active layer 1032, and a first conductivity type semiconductor layer 1031 are sequentially grown on a growth substrate 001 to form an epitaxial structure 103. In this embodiment, the epitaxial structure 103 is a red light epitaxial structure 103 of the AlGaInP quaternary system. The growth substrate 001 is a GaAs substrate. The GaAs substrate can meet the lattice matching requirements for epitaxial layer growth and improve the growth quality of the epitaxial structure 103. The first conductivity type semiconductor layer 1031 can be a P-type layer or an N-type layer, and the second conductivity type semiconductor layer 1033 can be an N-type layer or a P-type layer. In this embodiment, the first conductivity type semiconductor layer 1031 is preferably a P-type layer, and the second conductivity type semiconductor layer 1033 is an N-type layer.

[0069] S102: bonding the epitaxial structure to a transparent substrate;

[0070] form Figure 5 After the epitaxial structure 103 shown, Figure 6 As shown, a transparent substrate 101 is provided. In this embodiment, the transparent substrate 101 is a sapphire substrate. Since the sapphire substrate has good light transmittance and stability, it can improve the light extraction efficiency. A transparent bonding layer 102 is deposited on the surface of the first conductive type semiconductor layer 1031 of the epitaxial structure 103. The bonding layer 102 can be a silicon dioxide layer. Preferably, before depositing the transparent bonding layer 102, the surface of the first conductive type semiconductor layer 1031 is first roughened. After depositing the bonding layer 102, the side of the bonding layer 102 away from the first conductive type semiconductor layer 1031 is first polished to obtain a flat surface. The epitaxial structure 103 is bonded to the transparent substrate 101 through the flat surface of the bonding layer 102. Similarly, Figure 6 As shown, after the epitaxial structure 103 is bonded to the transparent substrate 101 , the growth substrate 001 is removed to expose the semiconductor layer 1033 of the second conductivity type.

[0071] S103: etching the epitaxial structure and forming a first contact electrode;

[0072] like Figure 7As shown, after removing the growth substrate 001, a photoresist layer is formed on the surface of the semiconductor layer 1033 of the second conductivity type, and the epitaxial structure is etched under the mask of the photoresist layer. In the region corresponding to the first pad 1081, the semiconductor layer 1033 of the second conductivity type and the active layer 1032 in the epitaxial structure 103 are etched, and the semiconductor layer 1031 of the first conductivity type is exposed to form the first mesa 1050, which is arranged in an array in the region corresponding to the first pad 1081. In addition, between adjacent light emitting elements, the first mesa 1050 is continuously etched to form the second mesa 1054, which is formed as a cutting path for cutting and separating the light emitting element later. Then, a conductive material is deposited on the first mesa 1050 to form Figure 1 The arrayed first contact electrode 1051 is shown. The conductive material may, for example, be a single-layer structure formed by one of Au, BeAu, AuZn, Pt, etc., or a multi-layer structure formed by a combination of two or more of them; or a single-layer structure formed by one of transparent conductive materials such as ITO, IZO, etc., or a multi-layer structure formed by a combination of two of them.

[0073] In this embodiment, in order to connect the semiconductor layer 1031 of the first conductivity type in the region corresponding to the second pad 1082, as shown in Figure 8 As shown, in the region corresponding to the second pad 1082, the epitaxial structure 103 is etched to form a groove 1050' that exposes the semiconductor layer 1031 of the first conductivity type, and the groove 1050' extends from the region of the second pad 1082 to the direction of the first pad 1081 and is connected to the through hole in the region corresponding to the first pad 1081. Preferably, the groove 1050' is connected to the first mesa 1050 in the region closest to the second pad 1082, and a conductive material is deposited in the groove 1050' to form a finger 1053 that is connected to the first contact electrode 1051 in the first mesa 1050.

[0074] S104: Forming a second contact electrode;

[0075] As shown in Figure 9 and Figure 10 A transparent dielectric layer 104 is deposited on the epitaxial structure 103 on which the first contact electrode 1051 and the finger 1053 are formed, covering the surface of the epitaxial structure 103 and the sidewalls of the exposed semiconductor layer 1033 of the second conductivity type and the active layer 1032, and filling the first mesa 1050 and the groove 1050', while covering and wrapping the first contact electrode 1051 and the finger 1053, to insulate the first contact electrode 1051 from the active layer 1032 and the semiconductor layer 1033 of the second conductivity type.

[0076] Then asFigure 9 and 10 As shown in Figure 9 and Figure 10 , first etch the transparent dielectric layer 104 to form an array of through holes exposing the second conductive type semiconductor layer 1033, and then deposit a conductive material in the through holes to form the second contact electrode 1052, which can be a single layer structure of one of Au, GeAuNi, Ni, Pt, etc., or a multi-layer structure of a combination of two or more of the above materials. Figure 1 As shown in Figure 1 , the second contact electrode 1052 is arrayed in the region corresponding to the first pad 1081, and is distributed along at least one concentric circle 002 centered at the first contact electrode 1051; in the region corresponding to the second pad 1082, the second contact electrode 1052 is distributed between the finger-shaped portions 1053, and is arrayed.

[0077] The above-described dot-matrix (i.e., array) design of the first contact electrode 1051 and the second contact electrode 1052 can reduce the waste of the effective light-emitting area caused by the first contact electrode 1051 (i.e., P-contact electrode), and can reduce the area of the ohmic contact interface between the contact electrode and the epitaxial layer, effectively improving the current spreading capability and the light-emitting efficiency of the chip.

[0078] S105: forming a metal reflective layer;

[0079] Referring also to Figure 10 , after forming the transparent dielectric layer 104 and the second contact electrode 1052, a metal reflective layer 106 is formed above the transparent dielectric layer 104, which covers at least the region corresponding to the second conductive type semiconductor 1033, to effectively reflect the light radiated by the active layer 1032, and to facilitate the subsequent insulating protective layer covering the sidewall of the metal reflective layer 106, preventing it from being oxidized or corroded. Optionally, the metal reflective layer 106 is formed as an Ag mirror layer, and the thickness thereof is not greater than 400 nm.

[0080] The metal reflective layer 106 is connected with the second contact electrode 1052 in the transparent dielectric layer 104 to form an electrical conduction structure. In order to prevent the first pad 1081 formed subsequently from being in communication with the metal reflective layer 106, after forming the above-described metal reflective layer 106, the metal reflective layer 106 is etched above the arrayed first contact electrode 1051 to form a first opening 1060, and preferably, the opening size of the first opening 1060 is greater than the size of the first mesa 1050.

[0081] S106: forming a first insulating protective layer;

[0082] AsFigure 11 As shown, in Figure 10 A first insulating protective layer 107 is deposited on the structure shown. The first insulating protective layer 107 covers the surface and sidewalls of the metal reflective layer 106 and fills the first opening 1060. The first insulating protective layer 107 is also formed on the sidewalls of the exposed first conductive type semiconductor layer 1031 and the sidewalls of the transparent dielectric layer 104 to protect the chip. After the first insulating protective layer 107 is formed, a patterned photoresist layer (not shown) is formed thereon and etching is performed using the patterned photoresist layer as a mask. Specifically, as shown in FIG. Figure 11 As shown, in the area corresponding to the first pad 1081, the first insulating protection layer 107 and the transparent dielectric layer 104 are etched until the first contact electrode 1051 is exposed, thereby forming a plurality of first through holes 1070 corresponding one to one to the first contact electrodes 1051; in the area corresponding to the second pad 1082, the first insulating protection layer 107 is etched until the metal reflective layer 106 is exposed, thereby forming a plurality of second through holes 1072.

[0083] S107: forming a first pad and a second pad.

[0084] Then, refer to Figures 1 to 3 As shown, in Figure 11 A metal material is deposited over the structure shown, and a metal material is deposited over the first insulating protective layer 107 to form a first pad 1081 and a second pad 1082 insulated from each other. The metal material simultaneously fills the first through-hole 1070 and the second through-hole 1072, respectively. As a result, the first pad 1081 is connected to the first contact electrode 1051, and the second pad 1082 is connected to the metal reflective layer 106, thereby forming an electrical connection with the second contact electrode 1052.

[0085] As mentioned above, when voltage is applied to the light-emitting element of this embodiment, the current can be electrically connected to the P-type epitaxial layer through the P contact electrode (i.e., the first contact electrode 1051). Since the first contact electrode 1051 is distributed in an array, the current can be evenly dispersed by the P-type epitaxial layer, effectively improving the problem of uneven current expansion, so that the current is evenly expanded to the P-type epitaxial layer, effectively improving the current expansion capability, and effectively improving the luminous efficiency of the light-emitting element.

[0086] Example 2

[0087] This embodiment also provides a flip-chip light-emitting element, referring to Figures 12 to 14The flip light emitting element 100' of the embodiment also comprises: a transparent substrate 101, an epitaxial structure 103 formed on the transparent substrate 101, a transparent dielectric layer 104 formed on the surface of the epitaxial structure 103, a metal reflective layer 106 formed above the transparent dielectric layer 104; a first insulating protective layer 107 formed on the surface of the metal reflective layer 106 and the sidewall of the epitaxial structure 103; and a pad area above the first insulating protective layer 107, which is formed with a first pad 1081 electrically connected to the semiconductor layer 1031 of the first conductive type, and a second pad 1082 electrically connected to the semiconductor layer 1033 of the second conductive type.

[0088] The same as the embodiment one will not be repeated, and the difference is that:

[0089] As shown in Figures 12 to 14 , in the flip light emitting element 100' of the embodiment, the first contact electrode 1051 and the second contact electrode 1052 are both distributed in an array in the entire epitaxial structure 103, and the second contact electrode 1052 is distributed on the concentric circle 002 with the first contact electrode 1051 as a circle. In addition, as shown in Figure 13 and Figure 14 , in the embodiment, a metal layer 109 and a second insulating protective layer 110 are further formed above the first insulating protective layer 107, wherein the metal layer 109 forms a mesh structure above the first insulating protective layer 107 to communicate the first contact electrode 1051. As shown in Figure 13 , at the position corresponding to the first contact electrode 1051, a conductive column 1071 is formed, which penetrates the transparent dielectric layer 103 and the first insulating protective layer 107 to communicate the first contact electrode 1051 and the metal layer 109.

[0090] In the area corresponding to the first pad 1081, a third through hole 1101 penetrating the second insulating protective layer 110 is formed, the first pad 1081 is formed in the third through hole 1101 and covers above the second insulating protective layer 110, the first pad 1081 is electrically connected to the first contact electrode 1051 through the metal layer 109 and the conductive column 1071, and further electrically connected to the semiconductor layer 1031 of the first conductive type. In the area corresponding to the second pad 1082, a fourth through hole 1102 is formed, which penetrates the second insulating protective layer 110 and the first insulating protective layer 107 to expose the metal reflective layer 106. Preferably, at the position corresponding to the fourth through hole 1102, the metal layer 109 is formed with a second opening 1090, and the aperture of the fourth through hole 1102 is smaller than the opening size of the second opening 1090, so as to ensure that the second pad 1082 formed in the fourth through hole 1102 is insulated from the metal layer 109 through the second insulating protective layer 110. Also as Figure 13As shown, the metal reflective layer 106 is connected to the second contact electrode 1052 . Therefore, the second pad 1082 is electrically connected to the first contact electrode 1051 via the metal reflective layer 106 , and further electrically connected to the second conductive type semiconductor layer 1033 .

[0091] In the flip-chip light-emitting element 100' of this embodiment, the first contact electrodes 1051 and the second contact electrodes 1052 are arranged in an array, with the second contact electrodes 1052 distributed along at least one concentric circle 002 centered on the first contact electrode 1051. This array arrangement of the first contact electrodes 1051 reduces the waste of effective light-emitting area caused by providing contact electrodes on the P-type semiconductor layer. Furthermore, it further reduces the area of ​​the interface between the first electrode and the first contact electrodes 1051, thereby improving the chip's luminous efficiency. The first contact electrodes 1051 are electrically connected via the mesh-like metal layer 109, facilitating current diffusion.

[0092] This embodiment also combines Figures 15 to 19 The manufacturing process of the flip-chip light-emitting element 100 ′ is described above. The difference between this process and the manufacturing method of the first embodiment is that:

[0093] like Figure 15 As shown, when etching the epitaxial structure 103 to form the first contact electrode 1051, a photoresist having an array-distributed window pattern is formed above the epitaxial structure 103, and then the second conductive type semiconductor layer 1033 and the active layer 1032 are etched through the windows to form an array-distributed first mesa 1050 exposing the first conductive type semiconductor layer 1031, and a conductive material is deposited on the first mesa 1050 to form an array-distributed first contact electrode 1051. Then, as shown in FIG. Figure 16 As shown, a transparent dielectric layer 104 is deposited on the surface and sidewalls of the epitaxial structure 103 and the first mesa 1050. The transparent dielectric layer 104 covers the first contact electrode 1051 and the surface and sidewalls of the exposed first mesa 1050. Then, as described in the first embodiment, a second contact electrode 1052 is formed in the transparent dielectric layer 104. The second contact electrodes 1052 are also distributed in an array and are distributed on at least one concentric circle 002 with the center of the first contact electrode 1051 as the center. Then, as described in the first embodiment, a second contact electrode 1052 is formed in the transparent dielectric layer 104. Figure 17 As shown, a metal reflective layer 106 is also formed, and a first opening 1060 corresponding to the first mesa 1050 is also formed in the metal reflective layer 106. Figure 18As shown, a first insulating protective layer 107 is formed above the metal reflective layer 106 and the transparent dielectric layer 104, and at the same time, the first insulating protective layer 107 and the transparent dielectric layer 104 are etched to form a via hole at the position corresponding to the first contact electrode 1051, and a conductive pillar 1071 is formed by depositing a conductive material in the via hole. The surface of the conductive pillar 1071 is flush with the surface of the first insulating protective layer 107. Then, a metal layer 109 is formed above the first insulating protective layer 107, which covers the conductive pillar 1071 and forms an electrical connection therewith. After the formation of the metal layer 109, the metal layer 109 is etched to form a second opening 1090 at the region corresponding to the second contact electrode 1052. It can be understood that, since the metal layer 109 is distributed in a mesh shape above the first insulating protective layer 107, the step of etching the metal layer 109 to form the second opening 1090 is not a necessary step, i.e., the second opening 1090 can be a mesh region formed by the mesh-shaped metal layer 109. It can be understood that the conductive pillar 1071 can be formed at the same time as the metal layer 109, i.e., after etching the first insulating protective layer 107 and the transparent dielectric layer 104 to form a via hole, a metal material is simultaneously deposited above the via hole and the first insulating layer to form the conductive pillar 1071 and the metal layer 109.

[0094] Then, as shown in Figure 19 , a second insulating protective layer 110 is formed above the metal layer 109, which covers the metal layer 109 and the exposed first insulating protective layer 107. Then, the second insulating protective layer 110 is etched to form a third via hole 1101 at the region corresponding to the first pad 1081, which exposes the metal layer 109 through the second insulating protective layer 110. The second insulating protective layer 110 and the first insulating protective layer 107 are etched to form a fourth via hole 1102 at the region corresponding to the second pad 1082, preferably at the region corresponding to the second opening 1090, which exposes the metal reflective layer 106 through the second insulating protective layer 110 and the first insulating protective layer 107. Then, referring again to Figure 13 and Figure 14 , a metal material is deposited above the structure shown in Figure 19 to form the first pad 1081 and the second pad 1082, respectively, which simultaneously fills the third via hole 1101 and the fourth via hole 1102, respectively. Thus, the first pad 1081 is electrically connected to the metal layer 109, and further forms an electrical connection with the first contact electrode 1051 and the first conductive type semiconductor layer 1031 through the conductive pillar 1071. The second pad 1082 is electrically connected to the metal reflective layer 106 and further forms an electrical connection with the second contact electrode 1052 and the second conductive type semiconductor layer 1033.

[0095] The array design of the first contact electrode 1051 and the second contact electrode 1052 of the light-emitting element of this embodiment allows the current to be electrically connected to the P-type epitaxial layer through the metal layer 109 and the P contact electrode (i.e., the first contact electrode 1051). Since the first contact electrodes 1051 are distributed in an array, the current can be evenly dispersed by the P-type epitaxial layer, further improving the problem of uneven current expansion, allowing the current to be evenly expanded to the P-type epitaxial layer, effectively improving the luminous efficiency of the light-emitting element.

[0096] Example 3

[0097] This embodiment also provides a flip-chip light-emitting element, such as Figure 20 As shown, the flip-chip light-emitting element of this embodiment also includes: a transparent substrate 101, an epitaxial structure 103 formed on the transparent substrate 101, a transparent dielectric layer 104 formed on the surface of the epitaxial structure 103, and a metal reflective layer 106 formed above the transparent dielectric layer 104; a first insulating protective layer 107 formed on the surface of the metal reflective layer 106 and on the sidewalls of the epitaxial structure 103; and a pad area located above the first insulating protective layer 107, the pad area being formed with a first pad 1081 electrically connected to the first conductive type semiconductor layer 1031, and a second pad 1082 electrically connected to the second conductive type semiconductor layer 1033.

[0098] The same points as those in Example 1 are not described in detail here, but the differences are as follows:

[0099] like Figure 20 As shown, a transparent conductive adhesive layer 120 is formed between the metal reflective layer 106 and the transparent dielectric layer 104. The transparent conductive adhesive layer 120 is formed in a dot-like structure. Preferably, the dot-like transparent conductive adhesive layer 120 is a transparent ITO layer. The thickness of the transparent conductive adhesive layer 120 is no greater than 10 nm to enhance the adhesion between the metal reflective layer 106 and the transparent dielectric layer. Furthermore, the dot-like structure of the transparent conductive adhesive layer 120 can reduce light absorption, thereby not affecting the chip's luminous efficiency and thus improving the chip's luminous efficiency.

[0100] In an alternative embodiment of this embodiment, if Figure 20 As shown, a metal adhesion layer 130 may be formed between the metal reflective layer 106 and the first insulating protective layer 107. The metal adhesion layer 130 is used to enhance the adhesion between the metal reflective layer 106 and the first insulating protective layer 107, while protecting the metal reflective layer 106 from oxidation. Optionally, the metal adhesion layer 130 may be a metal Ti layer with a thickness of no greater than 40 nm.

[0101] like Figure 20As shown, the present embodiment describes the position and thickness of the transparent conductive adhesive layer 120 and the metal adhesive layer 130 with the flip-chip light emitting element 100 shown in Embodiment One as an example. It should be understood that the flip-chip light emitting element of the present embodiment can also be the flip-chip light emitting element 100' provided in Embodiment Two, in which the transparent conductive adhesive layer 120 and the metal adhesive layer 130 described above can also be formed below and above the metal reflective layer 106. Here, no further elaboration is provided.

[0102] Embodiment Four

[0103] The present embodiment provides a light emitting device, as shown, the light emitting device 200 includes a circuit substrate 201 and a light emitting unit 202 disposed on the circuit substrate 201, wherein the light emitting unit 202 can be the flip-chip light emitting element provided in Embodiment One and / or Embodiment Two of the present application. Figure 21

[0104] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed in the present application should be covered by the claims of the present application.​

Claims

1. A flip-chip light-emitting element, characterized in that: include: transparent substrate; An epitaxial structure is formed on the transparent substrate, the epitaxial structure comprising a semiconductor layer of a first conductivity type, an active layer, and a semiconductor layer of a second conductivity type stacked in sequence from bottom to top; a transparent dielectric layer formed on a surface of the epitaxial structure, wherein a first contact electrode electrically connected to the semiconductor layer of the first conductivity type and a second contact electrode electrically connected to the semiconductor layer of the second conductivity type are formed in the transparent dielectric layer; a metal reflective layer formed above the transparent medium layer; a first insulating protective layer formed on the surface of the metal reflective layer and the sidewalls of the epitaxial structure; a pad region located above the first insulating protection layer, wherein the pad region is formed with a first pad electrically connected to the first conductive type semiconductor layer, and a second pad electrically connected to the second conductive type semiconductor layer; The first contact electrodes and the second contact electrodes are distributed in an array, and in a region corresponding to the first pad, the second contact electrodes are distributed on at least one concentric ring with the first contact electrode as the center.

2. The flip-chip light-emitting element according to claim 1, wherein: In the area corresponding to the second pad, the first contact electrode is formed into a plurality of finger-shaped portions, the second contact electrodes are distributed in an array between the finger-shaped portions, and the finger-shaped portions are connected to the first contact electrode in the area corresponding to the first pad.

3. The flip-chip light-emitting element according to claim 2, wherein: A first through hole is formed in a region corresponding to the first pad, the first through hole passing through the transparent dielectric layer and the first insulating protective layer, and the first pad is electrically connected to the first contact electrode via the first through hole; A second through hole is formed in a region corresponding to the second pad, the second through hole penetrates the first insulating protection layer, and the second pad is electrically connected to the metal reflective layer via the second through hole.

4. The flip-chip light-emitting element according to claim 1, wherein: The metal reflection layer is an Ag mirror reflection layer.

5. The flip-chip light-emitting element according to claim 1, wherein In the area corresponding to the second pad, the second contact electrodes are also distributed on a plurality of concentric rings with the first contact electrode as the center.

6. The flip-chip light-emitting element according to claim 5, wherein: Also includes: a metal layer, located above the first insulating protective layer, wherein the metal layer is distributed in a mesh shape to be electrically connected to the first contact electrode; A second insulating protective layer is located above the metal layer, and the pad area is located above the second insulating protective layer, wherein: A conductive column is formed at a position corresponding to the first contact electrode, the conductive column penetrates the transparent dielectric layer and the first insulating protective layer, and is electrically connected to the metal layer and the first contact electrode; a third through hole is formed in an area corresponding to the first pad and penetrates the second insulating protective layer, and the first pad is electrically connected to the metal layer via the third through hole; A fourth through hole is formed in a region corresponding to the second pad. The fourth through hole penetrates the second insulating protection layer and the first insulating protection layer. The second pad is electrically connected to the metal reflective layer via the fourth through hole.

7. The flip-chip light-emitting element according to claim 1, wherein: It also includes a transparent conductive adhesion layer, which is located between the transparent medium layer and the metal reflective layer, and the transparent conductive adhesion layer is distributed in a dotted manner.

8. The flip-chip light-emitting element according to claim 7, wherein: The transparent conductive adhesion layer is a dot-shaped transparent ITO layer.

9. The flip-chip light-emitting element according to claim 1, wherein: The light emitting element is a red light or infrared light emitting element.

10. The flip-chip light-emitting element according to claim 1, wherein The invention also includes a transparent bonding layer, through which the epitaxial structure is bonded to the transparent substrate.

11. The flip-chip light-emitting element according to claim 1, wherein The invention also includes a metal adhesion layer located between the metal reflective layer and the first insulating protection layer.

12. A light emitting device, characterized in that: The invention comprises a circuit substrate and a light-emitting element located on the circuit substrate, wherein the light-emitting element is the flip-chip light-emitting element according to any one of claims 1 to 11.

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