Light emitting diode structure

Abstract

The utility model relates to a light emitting diode structure. The light emitting diode comprises a substrate; the epitaxial structure is arranged on the substrate and comprises a buffer layer, a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially arranged along the substrate; the epitaxial structure comprises a middle part and side parts located on the two sides of the middle part, and the middle part further comprises a first middle part and a second middle part which are arranged at intervals; first extension steps are respectively arranged along two sides of the side part; second epitaxial steps are formed on two sides of the middle part I; the second middle part is configured to be a second groove; the current blocking layer comprises a first current blocking layer and a second current blocking layer; the transparent conducting layer covers the first current blocking layer; the P bonding pad structure comprises a P-type extension strip; the N bonding pad structure comprises a first N-type extension strip and a second N-type extension strip. According to the utility model, the light blocking effect can be effectively reduced, the current congestion risk is reduced, and the brightness and long-term reliability of the LED device are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor technology, light emitting diode technology especially is a kind of light emitting diode structure. BACKGROUND

[0002] Light emitting diode (LED) is a kind of semiconductor device that can efficiently convert electrical energy into light energy, with low energy consumption, long life, fast response, environmental protection and other advantages, has been widely used in lighting, display, backlight and other fields. However, with the continuous growth of LED application demand, higher requirements are put forward for the brightness, light emitting efficiency and long-term reliability of LED.

[0003] At present, the N region extension strip (N-Finger) in LED structure is usually designed with equal width or close width, and there is no epitaxial step below the extension strip. This design has the following defects: there is a light blocking effect, which is due to the N region extension strip shielding part of the light, resulting in reduced light extraction efficiency, affecting the overall luminous brightness of LED. To improve the light extraction efficiency, the prior art often solves it by increasing the current blocking (CB) area or raising the N region extension strip. However, when the N region extension strip and the N-type semiconductor contact area is reduced, current congestion is easy to occur at the injection point, causing high current density, and then causing the extension strip to overheat and burn out, affecting the service life of LED. SUMMARY

[0004] Therefore, the utility model provides a kind of light emitting diode structure, can effectively reduce light blocking effect, reduce current congestion risk, while improving the brightness and long-term reliability of LED device.

[0005] To solve the above technical problems, the utility model provides a kind of light emitting diode structure, comprising:

[0006] Substrate;

[0007] Epitaxial structure, disposed on the substrate, including buffer layer, first semiconductor layer, active layer and second semiconductor layer sequentially disposed along the substrate;

[0008] Wherein, the epitaxial structure includes middle part and side part located at both sides of the middle part, and the middle part further includes middle part one and middle part two arranged at intervals;

[0009] First epitaxial step extending from the second semiconductor layer to the first semiconductor layer is respectively arranged along both sides of the side part;Second epitaxial step is formed at both sides of the middle part one, and first recess is formed between the adjacent first epitaxial step;The middle part two is configured as second recess, and the second recess extends to the first epitaxial step adjacent to both sides thereof;

[0010] a current blocking layer, including a first current blocking layer disposed on the side surface and a second current blocking layer covering the surface and side surface of the middle part one;

[0011] a transparent conductive layer disposed on the side surface and covering the first current blocking layer;

[0012] a P-pad structure including a P-type extension bar in contact with the surface of the first current blocking layer;

[0013] an N-pad structure including a first N-type extension bar in contact with the surface of the second current blocking layer and a second N-type extension bar in contact with the bottom wall of the second groove.

[0014] In an embodiment of the present application, an insulating protective layer is further included, which covers the transparent conductive layer, the first epitaxial step, the second current blocking layer, the first groove and the second groove.

[0015] In an embodiment of the present application, the insulating protective layer and the current blocking layer are both made of silicon dioxide.

[0016] In an embodiment of the present application, the transparent conductive layer forms a first step structure on both sides.

[0017] In an embodiment of the present application, the length and spacing ratio of the second current blocking layer is between 2 and 10.

[0018] In an embodiment of the present application, the width ratio of the second N-type extension bar and the first N-type extension bar is between 1.5 and 5.

[0019] In an embodiment of the present application, the first current blocking layer and the second current blocking layer are at the same height.

[0020] In an embodiment of the present application, the back surface of the substrate is provided with a Bragg reflection layer.

[0021] In an embodiment of the present application, the N-pad structure includes an N-pad body connecting the first N-type extension bar and the second N-type extension bar, the P-pad structure includes a P-pad body connecting the P-type extension bar, and a second step structure is disposed on the epitaxial structure below the N-pad body.

[0022] In an embodiment of the present application, the N-pad body and the P-pad body are at the same height.

[0023] Compared with the prior art, the above technical scheme of the utility model has the following advantages:

[0024] The utility model discloses a light emitting diode structure, in the epitaxial structure of LED, adopt high density's current blocking layer distribution mode, through setting mesa step below N type extension strip, through the overall height of N area extension strip promotion, reduced the shadow effect of light in N area extension strip area. This structure not only reduces the shielding of N area extension strip to light, improves the light efficiency, and also optimizes the injection path of current, further reduces the possibility of current congestion. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to make the content of the utility model more easily be clearly understood, below according to the specific embodiment of the utility model and combining with the drawings, the utility model is further detailed.

[0026] Figure 1 It is the structure schematic diagram of the utility model light emitting diode structure.

[0027] Figure 2 It is the structure schematic diagram of the utility model light emitting diode structure. Figure 1 It is the structure schematic diagram of the utility model light emitting diode structure.

[0028] Figure 3 It is the structure schematic diagram of the utility model light emitting diode structure. Figure 1 It is the structure schematic diagram of the utility model light emitting diode structure.

[0029] Figure 4 It is the second current blocking layer distribution structure schematic diagram.

[0030] Figure 5 It is the second step structure structure schematic diagram below N pad body.

[0031] Explanation of the drawing mark of specification:

[0032] 1, substrate;

[0033] 2, epitaxial structure;2a, side part;201a, first epitaxial step;202a, first recess;2b, intermediate part one;201b, second epitaxial step;2c, intermediate part two;201c, second recess;21, buffer layer;22, first semiconductor layer;23, active layer;24, second semiconductor layer;

[0034] 3, Bragg reflection layer;

[0035] 4, current blocking layer;41, first current blocking layer;42, second current blocking layer;

[0036] 5, transparent conductive layer;51, first step structure;

[0037] 6, P-pad structure; 61, P-type extension bar; 62, P-pad body;

[0038] 7, N-pad structure; 71, first N-type extension bar; 72, second N-type extension bar; 73, N-pad body; 74, second step structure;

[0039] 8, Insulating protective layer. DETAILED DESCRIPTION

[0040] The utility model will be further explained in connection with the drawings and specific embodiments, so that the person skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation of the utility model.

[0041] In the utility model, if the direction (up, down, left, right, front and back) is described, it is only for the convenience of describing the technical scheme of the utility model, and is not indicated or implied that the indicated technical features must have a specific orientation, structure and operation, so it cannot be understood as the limitation of the utility model.

[0042] In the utility model, the meaning of "several" is one or more, and the meaning of "multiple" is two or more, and "greater than", "less than", "more than" and the like are not included in the number; "above", "below", "within" and the like are included in the number. In the description of the utility model, if "first" and "second" are described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0043] In the utility model, unless otherwise explicitly limited, the words "set", "install", "connect" and the like should be broadly understood, for example, they can be directly connected, or indirectly connected through an intermediate medium; can be fixedly connected, or can be detachably connected, or can be integrally formed; can be mechanically connected, or can be electrically connected or can communicate with each other; it can be the communication or interaction relationship between the two elements inside the two elements. The person skilled in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.

[0044] Referring to Figures 1 to 3 The utility model discloses a light emitting diode structure, including:

[0045] Substrate 1;

[0046] Epitaxial structure 2 is arranged on substrate 1, including buffer layer 21, first semiconductor layer 22, active layer 23 and second semiconductor layer 24 arranged in sequence along substrate 1;

[0047] a Bragg reflector layer 3 disposed on the back of the substrate 1;

[0048] The epitaxial structure 2 comprises a middle part and side parts 2a on both sides of the middle part, and the middle part further comprises a first middle part 2b and a second middle part 2c arranged at intervals.

[0049] First epitaxial steps 201a extending from the second semiconductor layer 24 to the first semiconductor layer 22 are arranged on both sides of the side parts 2a; second epitaxial steps 201b are formed on both sides of the first middle part 2b and first grooves 202a are formed between the adjacent first epitaxial steps 201a; the second middle part 2c is configured as a second groove 201c extending to the first epitaxial steps 201a on both sides thereof.

[0050] A current blocking layer 4 comprising a first current blocking layer 41 disposed on the surface of the side part 2a and a second current blocking layer 42 covering the surface and side surface of the first middle part 2b.

[0051] A transparent conductive layer 5 disposed on the surface of the side part 2a and covering the first current blocking layer 41.

[0052] A P-pad structure 6 comprising a P-type extension strip 61 in contact with the surface of the first current blocking layer 41.

[0053] An N-pad structure 7 comprising a first N-type extension strip 71 in contact with the surface of the second current blocking layer 42 and a second N-type extension strip 72 in contact with the bottom wall of the second groove 201c.

[0054] In one embodiment, referring to Figures 2 to 3 a protective insulating layer 8 covering the transparent conductive layer 5, the first epitaxial steps 201a, the second current blocking layer 42, the first grooves 202a and the second groove 201c.

[0055] In one embodiment, the protective insulating layer 8 and the current blocking layer 4 are both made of silicon dioxide.

[0056] In one embodiment, first step structures 51 are formed on both sides of the transparent conductive layer 5.

[0057] In one embodiment, referring to Figure 4 the ratio L1:L2 between the length and pitch of the second current blocking layer 42 is between 2 and 10.

[0058] In one embodiment, referring to Figures 2 to 3As shown, the ratio W2:W1 of the width of the second N-type extension bar 72 and the first N-type extension bar 71 is between 1.5 and 5. The N-type extension bar is widened at the low step area (i.e. the second recess 201c), reducing the light blocking effect, improving the utilization of light, and further optimizing the lighting efficiency.

[0059] In one embodiment, the first current blocking layer 41 and the second current blocking layer 42 are at the same height.

[0060] In one embodiment, the N-pad structure 7 includes an N-pad body 73 connecting the first N-type extension bar 71 and the second N-type extension bar 72, and the P-pad structure 6 includes a P-pad body 62 connecting the P-type extension bar 61, and the N-pad body 73 and the P-pad body 62 are at the same height.

[0061] In one embodiment, referring to Figure 5 As shown, a second step structure 74 is arranged on the epitaxial structure 2 below the N-pad body 73.

[0062] The convex-concave mesa step morphology of the epitaxial layer structure not only optimizes the light propagation path, reduces the reflection and absorption loss of light, but also enhances the heat management capability of the device, and promotes the effective dissipation of heat. The Mesa step is arranged below the N-CB (first N-type extension bar 71), the overall height of the N region extension bar is increased, and the shadow effect of light in the N region extension bar area is reduced. This structure not only reduces the blocking of light by the N region extension bar, improves the light collection efficiency, but also optimizes the current injection path, and further reduces the possibility of current congestion.

[0063] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A light emitting diode structure, characterized by The application relates to a semiconductor device, which comprises the following parts: a substrate (1); an epitaxial structure (2) arranged on the substrate (1) and comprising a buffer layer (21), a first semiconductor layer (22), an active layer (23) and a second semiconductor layer (24) arranged in sequence along the substrate (1); wherein the epitaxial structure (2) comprises a middle part and side parts (2a) located on both sides of the middle part, the middle part further comprises a middle part one (2b) and a middle part two (2c) arranged at intervals; first epitaxial steps (201a) extending from the second semiconductor layer (24) to the first semiconductor layer (22) are arranged on both sides of the side parts (2a); second epitaxial steps (201b) are formed on both sides of the middle part one (2b) and first grooves (202a) are formed between the second epitaxial steps (201b) and the adjacent first epitaxial steps (201a); the middle part two (2c) is configured as a second groove (201c) extending to the first epitaxial steps (201a) on both sides of the middle part two (2c); a current blocking layer (4) comprising a first current blocking layer (41) arranged on the surface of the side parts (2a) and a second current blocking layer (42) covering the surface and side surface of the middle part one (2b); a transparent conductive layer (5) arranged on the surface of the side parts (2a) and covering the first current blocking layer (41); a P-pad structure (6) comprising a P-type extension strip (61) in contact with the surface of the first current blocking layer (41); an N-pad structure (7) comprising a first N-type extension strip (71) in contact with the surface of the second current blocking layer (42) and a second N-type extension strip (72) in contact with the bottom wall of the second groove (201c).

2. A light emitting diode structure according to claim 1, wherein An insulating protective layer (8) is further arranged on the transparent conductive layer (5), the first epitaxial steps (201a), the second current blocking layer (42), the first grooves (202a) and the second groove (201c).

3. A light emitting diode structure according to claim 2, wherein Both the insulating protective layer (8) and the current blocking layer (4) are made of silicon dioxide.

4. The light emitting diode structure of claim 1, wherein, First step structures (51) are formed on both sides of the transparent conductive layer (5).

5. A light-emitting diode structure according to claim 1, characterized in that, The length-to-spacing ratio of the second current blocking layer (42) is between 2 and 10.

6. The light emitting diode structure of claim 1, wherein, The width ratio of the second N-type extension strip (72) to the first N-type extension strip (71) is between 1.5 and 5.

7. A light-emitting diode structure according to claim 1, characterized in that, The first current blocking layer (41) and the second current blocking layer (42) are located at the same height.

8. The light emitting diode structure of claim 1, wherein, A Bragg reflection layer (3) is arranged on the back surface of the substrate (1).

9. A light-emitting diode structure according to claim 1, characterized in that, The N-pad structure (7) comprises an N-pad body (73) connecting the first N-type extension strip (71) and the second N-type extension strip (72), the P-pad structure (6) comprises a P-pad body (62) connecting the P-type extension strip (61), and a second step structure (74) is arranged on the epitaxial structure (2) below the N-pad body (73).

10. A light-emitting diode structure according to claim 9, characterized in that, The N-pad body (73) and the P-pad body (62) are located at the same height.

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