CN108538983A - LED structure - Google Patents

Abstract

The invention provides a light emitting diode structure, which comprises a substrate, a semiconductor epitaxial layer and a reflecting conductive structure layer. The semiconductor epitaxial layer is disposed on the substrate and exposes a portion of the substrate. The reflective conductive structure layer covers a portion of the semiconductor epitaxial layer and a portion of the substrate exposed by the semiconductor epitaxial layer.

Description

LED structure

The present invention is a divisional application of the invention patent application with the application number 201310331658.6 and the invention name "Light Emitting Diode Structure" filed on August 1, 2013.

technical field

The present invention relates to a semiconductor structure, and more particularly to a light emitting diode structure.

Background technique

Generally speaking, when making light-emitting diode wafers, the substrate is usually provided first, and an epitaxial structure is formed on the substrate by epitaxial growth, and then electrodes are arranged on the epitaxial structure to provide electrical energy, so that the photoelectric effect can be utilized. And glow. Afterwards, a plurality of criss-crossing cutting lines are formed in the epitaxial structure by using lithographic etching technology. Wherein, each two adjacent vertical dicing lines and two adjacent horizontal dicing lines together define a light emitting diode crystal grain. Afterwards, the subsequent grinding and dicing process is performed to divide the LED wafer into many LED crystal grains, and then complete the production of LEDs.

In order to increase the light extraction efficiency of light-emitting diodes, in the prior art, an ohmic contact layer, a reflective layer, and a barrier layer are sequentially added on the epitaxial structure, wherein the ohmic contact layer, reflective layer, and barrier layer only cover part of the epitaxial structure superior. Although the above method can increase the light extraction efficiency of the light emitting diode, the light extraction efficiency cannot meet the current requirement for high light extraction efficiency. Therefore, how to fully improve the light extraction efficiency of light emitting diodes is still an urgent problem to be overcome.

Contents of the invention

The invention provides a light-emitting diode structure with good light-emitting efficiency.

The LED structure of the embodiment of the present invention includes a substrate, a semiconductor epitaxial structure, a first insulating layer, a reflective layer, a second insulating layer and at least one electrode. The semiconductor epitaxial structure is configured on the substrate, and part of the substrate is exposed. The first insulating layer covers part of the semiconductor epitaxy structure and part of the substrate exposed by the semiconductor epitaxy structure. The reflective layer is configured on the first insulating layer, and the second insulating layer is configured on the reflective layer. The electrodes are disposed on the second insulating layer and electrically connected to the semiconductor epitaxy structure.

The LED structure of the embodiment of the present invention includes a substrate, a semiconductor epitaxial structure, a transparent conductive layer, a reflective layer, a first insulating layer and at least one electrode. The semiconductor epitaxial structure is configured on the substrate, and part of the substrate is exposed. The transparent conductive layer is configured on the semiconductor epitaxial structure. The reflective layer is configured on part of the transparent conductive layer and extends to cover part of the substrate exposed by the semiconductor epitaxial layer. The first insulating layer is configured on the reflective layer. The electrodes are arranged on the second insulating layer, and the electrodes are electrically connected to the semiconductor epitaxy structure.

The LED structure of the embodiment of the present invention includes a substrate, a semiconductor epitaxial structure, a first insulating layer, a reflective layer, a second insulating layer and at least one first electrode. The semiconductor epitaxial structure is configured on the substrate. The first insulating layer covers part of the semiconductor epitaxial structure and part of the substrate. The reflective layer is configured on the first insulating layer, and the second insulating layer is configured on the reflective layer. The first electrode is disposed on the second insulating layer, and the electrode is electrically connected to the semiconductor epitaxy structure.

The LED structure of the embodiment of the present invention includes a substrate, a semiconductor epitaxial structure, a transparent conductive layer, a reflective layer, a first insulating layer and at least one electrode. The semiconductor epitaxial structure is configured on the substrate. The transparent conductive layer is configured on the semiconductor epitaxial structure. The reflective layer is located on the substrate and covers at least part of the transparent conductive layer and at least part of the semiconductor epitaxy structure. The first insulating layer covers at least part of the reflective layer, at least part of the transparent conductive layer and at least part of the semiconductor epitaxy structure. The electrodes are arranged on the second insulating layer, and the electrodes are electrically connected to the semiconductor epitaxy structure.

Based on the above, since the LED structure of the present invention has a reflective conductive structure layer, and the reflective conductive structure layer covers part of the semiconductor epitaxial layer and the portion of the substrate exposed by the semiconductor epitaxial layer. Therefore, the reflective conductive structure layer can effectively reflect the light from the semiconductor epitaxy layer, and the portion of the substrate exposed by the semiconductor epitaxy layer also has the effect of reflection. In this way, the arrangement of the reflective conductive structure layer can effectively increase the reflective area, thereby effectively improving the light extraction efficiency of the overall light emitting diode structure.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a light emitting diode structure according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a light emitting diode structure according to another embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of a light emitting diode structure according to another embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a light emitting diode structure according to another embodiment of the present invention.

Explanation of reference signs:

100a, 100b, 100c, 100d: LED structures

110a, 110b: substrate

112a, 112b: upper surface

114b: annular inclined surface

120a: semiconductor epitaxial layer

122a: first type semiconductor layer

124a: light emitting layer

126a: second type semiconductor layer

130a, 130b, 130c, 130d: reflective conductive structural layer

132a, 132b, 132c, 132d: transparent conductive layer

134a, 134b, 134c, 134d: reflective layer

136a, 136b, 136c, 136d: barrier layer

140a, 140d: insulating layer

145a, 145d: electrical insulation layer

150a: first electrode

160a: second electrode

170a: Connection layer

A: imaginary circle

C: Depressed area

S1: The first semiconductor block

S2: Second semiconductor block

Detailed ways

FIG. 1 is a schematic cross-sectional view of a light emitting diode structure according to an embodiment of the present invention. Please refer to FIG. 1 , in the present embodiment, the LED structure 100a includes a substrate 110a, a semiconductor epitaxial layer 120a and a reflective conductive structure layer 130a. The semiconductor epitaxial layer 120a is disposed on the substrate 110a, and exposes a part of the substrate 110a (the imaginary circle A in FIG. 1 ). The reflective conductive structure layer 130a is disposed on the semiconductor epitaxial layer 120a, wherein the reflective conductive structure layer 130a covers part of the semiconductor epitaxial layer 120a and the portion of the substrate 110a exposed by the semiconductor epitaxial layer 120a.

More specifically, in this embodiment, the substrate 110a is, for example, a sapphire substrate, but not limited thereto, wherein the substrate 110a has an upper surface 112a. The semiconductor epitaxial layer 120a includes a first-type semiconductor layer 122a, a light-emitting layer 124a, and a second-type semiconductor layer 126a sequentially disposed on the substrate 110a. Here, the first-type semiconductor layer 122a is, for example, an N-type semiconductor layer, and the second-type semiconductor layer 126a is, for example, a P-type semiconductor layer, but not limited thereto. As shown in FIG. 1 , the semiconductor epitaxial layer 120 a does not completely cover the upper surface 112 a of the substrate 110 a, but exposes a part of the upper surface 112 a of the substrate 110 a.

In particular, the reflective conductive structure layer 130a of this embodiment is composed of a transparent conductive layer 132a, a reflective layer 134a, and a barrier layer 136a arranged in sequence. The transparent conductive layer 132a can be regarded as an ohmic contact layer, and its purpose is to increase the current conduction and make the current evenly spread, wherein the transparent conductive layer 132a is disposed on the semiconductor epitaxial layer 120a and the covering substrate 110a is exposed by the semiconductor epitaxial layer 120a out of the upper surface 112a. Here, the material of the transparent conductive layer 132 a is selected from indium tin oxide, aluminum-doped zinc oxide, indium zinc oxide, and one of the groups formed above. In this example, the transparent conductive layer 132a is made of indium tin oxide. The reflective layer 134a is disposed on the transparent conductive layer 132a. The reflective layer 134a can reflect the light from the semiconductor epitaxial layer 120a to the substrate 110a. When the light emitting diode structure 100a of the present invention is applied to, for example, a flip-chip light emitting diode, the light extraction efficiency can be improved. Here, the material of the reflective layer 134a is, for example, one selected from the group consisting of silver, chromium, nickel, aluminum and the above; or, the reflective layer 134a is, for example, a Bragg reflector. The reflective layer 134a in this example is made of silver. The barrier layer 136a is disposed on the reflective layer 134a and covers the upper surface 112a of the substrate 110a exposed by the semiconductor epitaxial layer 120a, wherein the barrier layer 136a not only has a reflective function, but also can protect the structure of the reflective layer 134a, Metal diffusion in the reflective layer 134a is avoided. Here, the edge of the barrier layer 136a is aligned with the edge of the substrate 110a, and the material of the barrier layer 136a is, for example, selected from titanium-tungsten alloy, titanium, tungsten, titanium nitride, tantalum, chromium, chrome-copper alloy, nitrogen Tantalum oxide and one of the groups formed above, in this embodiment, the barrier layer 136 a is composed of titanium, tungsten and titanium-tungsten alloy.

Moreover, the LED structure 100a of this embodiment further includes an insulating layer 140a, wherein the insulating layer 140a is disposed between the substrate 110a and the reflective conductive structure layer 130a and between the semiconductor epitaxial layer 120a and the reflective conductive structure layer 130a, so as to The effective electrical insulation is between the semiconductor epitaxial layer 120a and the reflective conductive structure layer 130a. As shown in FIG. 1, the insulating layer 140a of this embodiment is directly disposed on the semiconductor epitaxial layer 120a, and is extended along the sidewall of the semiconductor epitaxial layer 120a to be disposed on the substrate 110a exposed by the semiconductor epitaxial layer 120a. on the upper surface 112a. The transparent conductive layer 132a and the reflective layer 134a thereon do not completely cover the insulating layer 140a, while the barrier layer 136a extends along the sidewalls of the transparent conductive layer 132a and the reflective layer 134a to cover the insulating layer 140a. Here, the edge of the insulating layer 140a is also aligned with the edge of the barrier layer 136a and the edge of the substrate 110a.

In addition, the LED structure 100a of this embodiment further includes a first electrode 150a, a second electrode 160a and a connection layer 170a. The semiconductor epitaxial layer 120 a has a recessed region C, and the recessed region C divides the semiconductor epitaxial layer 120 a into a first semiconductor block S1 and a second semiconductor block S2 . The first electrode 150a is disposed on the first semiconductor block S1, and the second electrode 160a is disposed on the second semiconductor block S2, wherein the first electrode 150a and the second electrode 160a have electrical properties to provide electric energy. The connection layer 170a is disposed in the recessed region C and is electrically connected to the first electrode 150a and the semiconductor epitaxial layer 120a. Here, the materials of the first electrode 150a and the connection layer 170a can be the same or different, preferably different materials. The material of the first electrode 150a is selected from gold, tin, gold-tin alloy, and one of the groups formed above. The material of the connection layer 170a is selected from chromium, platinum, gold, aluminum, alloys of the above materials, and one of the groups formed by the above materials. The different materials enable better electrical connection between the first electrode 150a and the connection layer 170a, but it is not limited thereto. Here, the first electrode 150a is electrically connected to the first-type semiconductor layer 122a of the semiconductor epitaxial layer 120a through the connection layer 170a, and the second electrode 160a is connected to the second-type semiconductor layer of the semiconductor epitaxial layer 120a through the reflective conductive structure layer 130a. 126a is electrically connected to provide electrical energy through the first electrode 150a and the second electrode 160a to make the LED structure 100a emit light.

In addition, the LED structure 100a may further include an electrically insulating layer 145a, wherein the electrically insulating layer 145a is at least disposed between the first electrode 150a and the reflective conductive structure layer 130a and between the connection layer 170a and the reflective conductive structure layer 130a, for The reflective conductive structure layer 130a, the connection layer 170a and the first electrode 150a are electrically insulated. Here, the edge of the electrically insulating layer 145a is also aligned with the edge of the barrier layer 136a, the edge of the insulating layer 140 and the edge of the substrate 110a.

Since the LED structure 100a of this embodiment has a reflective conductive structure layer 130a, and the reflective conductive structure layer 130a covers part of the semiconductor epitaxial layer 120a and the portion of the substrate 110a exposed by the semiconductor epitaxial layer 120a. Therefore, the reflective conductive structure layer 130a can effectively reflect the light from the semiconductor epitaxial layer 120a, and make the portion of the substrate 110a exposed by the semiconductor epitaxial layer 120a also reflect. In this way, when the LED structure 100a is applied to, for example, a flip-chip design, the reflective conductive structure layer 130a can effectively increase the reflection area, thereby effectively improving the light extraction efficiency of the overall LED structure 100a.

It must be noted here that the following embodiments use the component numbers and part of the content of the previous embodiments, wherein the same numbers are used to denote the same or similar components, and descriptions of the same technical content are omitted. For the description of omitted parts, reference may be made to the foregoing embodiments, and the following embodiments will not be repeated.

FIG. 2 is a schematic cross-sectional view of a light emitting diode structure according to another embodiment of the present invention. Please refer to FIG. 2, the light emitting diode structure 100b of this embodiment is similar to the light emitting diode structure 100a of FIG. The inclined surface 114b, wherein the insulating layer 140b and the barrier layer 136b extend from the upper surface 112b to cover the annular inclined surface 114b. As shown in FIG. 2 , the transparent conductive layer 132 b and the reflective layer 134 b of the reflective conductive structure layer 130 b do not extend to cover the annular inclined surface 114 b.

FIG. 3 is a schematic cross-sectional view of a light emitting diode structure according to another embodiment of the present invention. Please refer to FIG. 3, the light emitting diode structure 100c of this embodiment is similar to the light emitting diode structure 100b of FIG. And the barrier layer 136c extends from the upper surface 112b to cover the annular inclined surface 114b, and the edges of the transparent conductive layer 132c, the reflective layer 134c and the barrier layer 136c are all aligned with the edge of the substrate 110b. With this design, the reflective conductive layer 130c is not only disposed on the upper surface of the substrate 110b, but also extends to cover the annular inclined surface 114b to increase the reflective area.

FIG. 4 is a schematic cross-sectional view of a light emitting diode structure according to another embodiment of the present invention. Please refer to FIG. 4, the light emitting diode structure 100d of this embodiment is similar to the light emitting diode structure 100b of FIG. The barrier layer 136d, the insulating layer 140d, and the electrical insulating layer 145d are all extended from the upper surface 112b to cover the annular inclined surface 114b and converge to the same position.

To sum up, since the LED structure of the present invention has a reflective conductive structure layer, and the reflective conductive structure layer covers part of the semiconductor epitaxial layer and the portion of the substrate exposed by the semiconductor epitaxial layer. Therefore, the reflective conductive structure layer can effectively reflect the light from the semiconductor epitaxy layer, and the portion of the substrate exposed by the semiconductor epitaxy layer also has the effect of reflection. In this way, the arrangement of the reflective conductive structure layer can effectively increase the reflective area, thereby effectively improving the light extraction efficiency of the overall light emitting diode structure.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention should be defined by the appended claims.

Claims (4)

1. a kind of light emitting diode construction, including：

Substrate has inclined surface；

Semiconductor epitaxial structure, setting on the substrate, and at least expose the inclined surface of the substrate, the semiconductor epitaxy knot Structure includes one first type semiconductor layer, a luminescent layer and one second type semiconductor layer, is sequentially arranged on the substrate, this is partly led One side surface of body epitaxial structure includes first type semiconductor layer, the luminescent layer and second type semiconductor layer；

First insulating layer covers entire side surface of the semiconductor epitaxial structure and at least partly inclined surface of the substrate, And expose the part semiconductor epitaxial structure；

First reflecting layer is at least partially disposed on the semiconductor epitaxial structure and first insulating layer；

Second reflecting layer is arranged on first reflecting layer and first insulating layer；

Second insulating layer is arranged on second reflecting layer；And

An at least electrode is arranged in the second insulating layer, and is electrically connected the semiconductor epitaxial structure.

2. a kind of light emitting diode construction, including：

Substrate has inclined surface；

Semiconductor epitaxial structure, setting on the substrate, and at least expose the inclined surface of the substrate, the semiconductor epitaxy knot Structure includes one first type semiconductor layer, a luminescent layer and one second type semiconductor layer, is sequentially arranged on the substrate, this is partly led One side surface of body epitaxial structure includes first type semiconductor layer, the luminescent layer and second type semiconductor layer；

First insulating layer covers entire side surface of the semiconductor epitaxial structure and at least partly inclined surface of the substrate, And expose the part semiconductor epitaxial structure；

Conductive layer is at least partially disposed in part semiconductor epitaxial structure that first insulating layer is exposed, and with this Semiconductor epitaxial structure is electrically connected；

First reflecting layer, setting cover at least partly inclined surface of the substrate on the conductive layer and first insulating layer；

Second reflecting layer is arranged on first reflecting layer；

Second insulating layer is arranged on second reflecting layer；And

An at least electrode is arranged on second reflecting layer, and is electrically connected the conductive layer and the semiconductor epitaxial structure.

3. light emitting diode construction according to claim 1 or 2, wherein first reflecting layer are metallic reflector or Bradley Lattice mirror layer.

4. light emitting diode construction according to claim 1 or 2, the wherein second insulating layer are also covered in the substrate extremely On the small part inclined surface.