CN114220895B - Light-emitting device and manufacturing method thereof - Google Patents

Abstract

The invention relates to a light-emitting device and a manufacturing method thereof. The upper surface of the side of the first insulating layer of the light emitting device, which is close to the first semiconductor layer, is provided with a gap formed by a groove partially blocked by the lower surface of the first semiconductor layer. According to the scheme provided by the invention, the gap is formed in the non-light-emitting surface area of the light-emitting device part, and the gap does not contain any solid or liquid material, so that the refractive index of photons emitted by the active layer at the gap can be greatly reduced, the reflection efficiency inside the device can be improved, and the light efficiency is improved.

Description

A light emitting device and a method for manufacturing the same

Technical Field

The present invention relates to the field of LED chip structures, and in particular to a light emitting device and a manufacturing method thereof.

Background technique

Light-emitting devices emit light by relying on photons emitted by the active layer. The photons emitted by the active layer are emitted in all directions with equal probability. Therefore, when the photons are emitted from the light-emitting direction, they will be reflected multiple times inside the device. Therefore, how to improve the reflection efficiency inside the light-emitting device and thereby increase the device's luminous efficiency is a technical problem that needs to be solved.

Summary of the invention

In order to overcome the problems existing in the related art, the present invention provides a light-emitting device and a method for manufacturing the same. By forming gaps in some non-light-emitting surface areas of the device, and the gaps do not contain any solid or liquid materials, the reflection efficiency inside the device can be improved and the light effect can be improved.

According to a first aspect of an embodiment of the present invention, there is provided a light-emitting device, comprising a first semiconductor layer, a second semiconductor layer, an active layer located between the first semiconductor layer and the second semiconductor layer, a first conductive layer electrically connected to the first semiconductor layer, a second conductive layer electrically connected to the first conductive layer, and an electrode electrically connected to the second conductive layer, wherein the first conductive layer, the second conductive layer and the electrode together constitute a first electrical connection layer, and further comprising a recess penetrating the first semiconductor layer and the active layer and extending to the inside of the second semiconductor layer, a first insulating layer covering a portion of the surface of the first semiconductor layer and partially exposed to the outside of the light-emitting device, a second insulating layer covering a sidewall of the recess and a side of the first electrical connection layer, a third conductive layer which is mostly in contact with the surface of the second insulating layer and is electrically connected to the second semiconductor layer, and a supporting substrate in contact with the third conductive layer;

An upper surface of the first insulating layer on a side close to the first semiconductor layer has a gap formed by a groove partially blocked by the lower surface of the first semiconductor layer.

Furthermore, the first conductive layer, the second conductive layer, the third conductive layer and the electrode all comprise a multi-layer metal structure.

Furthermore, when the support substrate is made of a non-conductive material, the third conductive layer is a second electrical connection layer; when the support substrate is conductive, the third conductive layer and the support substrate together constitute an electrical connection layer.

According to a second aspect of an embodiment of the present invention, there is provided a method for manufacturing a light emitting device, comprising:

Manufacturing an initial epitaxial structure, including sequentially growing a second semiconductor layer, an active layer, and a first semiconductor layer on an epitaxial growth substrate;

Making a recess that penetrates the first semiconductor layer and the active layer and extends into the second semiconductor layer;

The first conductive layer is formed on a portion of the surface of the first semiconductor layer;

A gap sacrificial layer is formed on the surface of the first semiconductor layer outside the first conductive layer;

A first insulating layer is formed on the surface of the first semiconductor layer outside the first conductive layer, wherein the first insulating layer wraps the gap sacrificial layer;

Forming a second conductive layer on a portion of the surface of the first insulating layer and on the surface of the first conductive layer;

forming a second insulating layer on the remaining surface of the first insulating layer and the surface of the second conductive layer;

forming a third conductive layer on the surface of the second insulating layer;

Making a supporting substrate on the surface of the third conductive layer;

Etching away the epitaxial growth substrate and a portion of the epitaxial layer consisting of the first semiconductor layer, the active layer and the second semiconductor layer to expose the first insulating layer and a portion of the gap sacrificial layer;

The void sacrificial layer is etched away.

Furthermore, the method further comprises:

forming an electrode on a portion of the surface of the second conductive layer;

Furthermore, the method further comprises:

The light emitting surface of the second semiconductor layer is roughened.

The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

A gap is formed in the non-light-emitting surface area of the light-emitting device, and the gap does not contain any solid or liquid material, which can greatly reduce the refractive index of photons emitted by the active layer at the gap, thereby improving the reflection efficiency inside the device and improving the light effect.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like parts throughout the exemplary embodiments of the present invention.

FIG1 is a schematic diagram of the structure of an existing light emitting device;

FIG2 is a schematic structural diagram of a light emitting device provided by an embodiment of the present invention;

FIG3 is a comparative schematic diagram of reflection of incident photons in an existing light-emitting device and a light-emitting device provided in this embodiment of the present application;

FIG4 is a flow chart of a method for manufacturing a light emitting device provided in an embodiment of the present invention;

FIG5 is a schematic diagram of the initial epitaxial structure of the light emitting device formed after step S401 is completed;

FIG6 is a schematic diagram of the structure of the light emitting device after step S402 is completed;

FIG7 is a schematic diagram of the structure of the light emitting device after step S403 is completed;

FIG8 is a schematic diagram of the structure of the light emitting device after step S404 is completed;

FIG9 is a schematic diagram of the structure of the light emitting device after step S405 is completed;

FIG10 is a schematic diagram of the structure of the light emitting device after step S406 is completed;

FIG11 is a schematic diagram of the structure of the light emitting device after steps S407-S409 are completed;

FIG12 is a schematic diagram of the structure of the light emitting device after step S410 is completed;

FIG. 13 is a schematic diagram of the structure of the light emitting device after step S411 is completed.

Explanation of the figure numbers: 1: second semiconductor layer, 2: active layer, 3: first semiconductor layer, 4: first conductive layer, 5: second conductive layer, 6: electrode, 7: recess, 8: first insulating layer, 9: second insulating layer, 10: third conductive layer, 11: supporting substrate, 12: groove, 13: gap sacrificial layer.

Detailed ways

The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

The terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "the" and "the" used in the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and/or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

It should be understood that although the terms "first", "second", "third", etc. may be used to describe various information in the present invention, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

As shown in Figure 1, it is a schematic diagram of the structure of an existing light-emitting device, including a first semiconductor layer 3, a second semiconductor layer 1, an active layer 2 located between the first semiconductor layer 3 and the second semiconductor layer, a first conductive layer 4 electrically connected to the first semiconductor layer 3, a second conductive layer 5 electrically connected to the first conductive layer 4, and an electrode 6 electrically connected to the second conductive layer 5, wherein the first conductive layer 4, the second conductive layer 5 and the electrode 6 together constitute a first electrical connection layer, and also include a recess 7 that penetrates the first semiconductor layer 3 and the active layer 2 and extends to the inside of the second semiconductor layer 1, a first insulating layer 8 covering a portion of the surface of the first semiconductor layer 3 and partially exposed to the outside of the light-emitting device, a second insulating layer 9 covering the side wall of the recess 7 and one side of the first electrical connection layer, a third conductive layer 10 that is mostly in contact with the surface of the second insulating layer 9 and is electrically connected to the second semiconductor layer 1, and a supporting substrate 11 in contact with the third conductive layer 10.

The photons emitted by the active layer 2 of the light emitting device are emitted in all directions, so when the photons are emitted from the light emitting direction, they will be reflected multiple times inside the device. Therefore, improving the reflection efficiency inside the device is an important means to increase the light efficiency of the device. Based on the above cognition, the applicant conducted the following analysis and research.

On the one hand, when light reaches the interface between different materials, reflection occurs, and reflectivity = (n1-n2) ² /(n1+n2) ² . Therefore, when n1 remains unchanged, the value of n2 decreases, the numerator on the left side of the equation increases and the denominator decreases, thereby increasing the reflectivity.

On the other hand, when light passes through the interface of high refractive index to low refractive index material, total reflection will occur. The total reflection angle = arcsin (n2/n1), n2 is the refractive index of the low refractive index material, and n1 is the refractive index of the high refractive index material. Therefore, when n2 decreases, the total reflection angle becomes smaller and the total reflection probability increases.

The lowest known refractive index is vacuum, which has a refractive index of 1. The next lowest known refractive index is air, which has a refractive index of 1.00029. Any other solid or liquid material has a higher refractive index.

Therefore, if a region without any solid or liquid material is formed at the reflective position of the light emitting device, an ideal reflective effect will be obtained.

Based on the above understanding, a structural schematic diagram of a light-emitting device provided by an embodiment of the present invention is shown in Figure 2, in which the upper surface of the first insulating layer 8 of the light-emitting device close to the first semiconductor layer 3 has a gap formed by a groove 12 partially blocked by the lower surface of the first semiconductor layer 3.

FIG3 is a comparative schematic diagram of the reflection of incident photons in an existing light-emitting device and a light-emitting device provided in this embodiment of the present application. As shown in FIG3, in the existing light-emitting device, after the incident light passes through the first conductive layer 4, it is reflected on the surface in contact with the first insulating layer 8, while based on the structure of the light-emitting device in this embodiment of the present application, after the incident light passes through the first conductive layer 4, it is reflected on the surface in contact with the gap. Since the reflection occurs between the solid material and the air or vacuum in the gap, based on the above description, the probability of total reflection is much higher than that of the existing light-emitting device.

A light-emitting device provided by an embodiment of the present invention forms a gap in a non-light-emitting surface area of the light-emitting device, and the gap does not contain any solid or liquid material, which can greatly reduce the refractive index of photons emitted by the active layer 2 at the gap, thereby improving the reflection efficiency inside the device and improving the light effect.

Optionally, in this embodiment, the first conductive layer 4, the second conductive layer 5, the third conductive layer 10 and the electrode 6 all include a multi-layer metal structure.

Optionally, in this embodiment, when the support substrate 11 is made of a non-conductive material, the third conductive layer 10 is a second electrical connection layer, and when the support substrate 11 is conductive, the third conductive layer 10 and the support substrate 11 together constitute an electrical connection layer.

The embodiment of the present invention further provides a method for manufacturing a light emitting device, as shown in FIG4 , the method comprising:

S401, manufacturing an initial epitaxial structure, including sequentially growing a second semiconductor layer 1, an active layer 2 and a first semiconductor layer 3 on an epitaxial growth substrate;

FIG. 5 is a schematic diagram of an initial epitaxial structure. The specific process may adopt existing technology, which is not described in detail in this embodiment.

S402, making a recess 7 penetrating through the first semiconductor layer 3 and the active layer 2 and extending to the inside of the second semiconductor layer 1;

In this step, UV mask patterning and chemical etching can be used to obtain a recess 7 that penetrates the first semiconductor layer 3 and the active layer 2 and extends into the second semiconductor layer 1, and its specific structure is shown in Figure 7. The specific process can adopt the existing technology, which is not described in detail in this embodiment.

S403, forming the first conductive layer 4 on a portion of the surface of the first semiconductor layer 3;

In this step, the first conductive layer 4 can be obtained by patterning with a UV mask, evaporating, and peeling. The specific structure is shown in FIG. 7 . The specific process can adopt the existing technology, which will not be described in detail in this embodiment.

S404, forming a gap sacrificial layer on the surface of the first semiconductor layer 3 outside the first conductive layer 4;

As shown in FIG. 8 , in this step, the void sacrificial layer required by the present invention can be obtained by using the known UV mask patterning, evaporation, and stripping methods.

The void sacrificial layer is a solid material that can be etched away in subsequent processes.

S405, forming a first insulating layer 8 on the surface of the first semiconductor layer 3 outside the first conductive layer 4, wherein the first insulating layer 8 wraps the gap sacrificial layer;

In this step, the first insulating layer 8 can be obtained by using known methods such as vapor deposition, UV mask patterning, and etching. As shown in FIG. 9 , most of the first insulating layer 8 is in contact with the first semiconductor and wraps the gap sacrificial layer together with the first semiconductor layer 3 .

S406, forming a second conductive layer 5 on a partial surface of the first insulating layer 8 and a surface of the first conductive layer 4;

In this step, the second conductive layer 5 can be obtained by using the known UV mask patterning, evaporation, and stripping methods. The specific structure is shown in FIG. 10 .

S407, forming a second insulating layer 9 on the remaining surface of the first insulating layer 8 and the surface of the second conductive layer 5;

S408, forming a third conductive layer 10 on the surface of the second insulating layer 9;

S409, manufacturing a supporting substrate 11 on the surface of the third conductive layer 10;

The specific structure of manufacturing the second insulating layer 9, the third conductive layer 10 and the supporting substrate 11 is shown in FIG. 11. The specific process can adopt the existing technology, which is not described in detail in this embodiment.

S410, etching away the epitaxial growth substrate and part of the epitaxial layer consisting of the first semiconductor layer 3, the active layer 2 and the second semiconductor layer 1 to expose the first insulating layer 8 and part of the gap sacrificial layer;

In this step, a portion of the epitaxial layer is etched away by patterning with an ultraviolet mask and chemical etching to expose the first insulating layer 8 and a portion of the gap sacrificial layer. The specific structure is shown in FIG. 12 .

S411, etching away the gap sacrificial layer.

In this step, an etching solution for the void sacrificial layer is used to etch away the sacrificial layer, and the void required in the present invention is obtained. The specific structure is shown in FIG. 13 .

Further, as shown in FIG4 , the method further includes:

S412, forming an electrode 6 on the surface of the second conductive layer 5;

The specific structure is shown in FIG2 , and the specific process can adopt the existing technology, which is not described in detail in this embodiment.

Further, as shown in FIG4 , the method further includes:

S413 , roughening the light-emitting surface of the second semiconductor layer 1 .

The light extraction efficiency of the light emitting device can be improved by roughening treatment. The specific structure is shown in FIG. 2 . The specific process can adopt the existing technology, which will not be described in detail in this embodiment.

The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (6)

1. A light-emitting device, comprising a first semiconductor layer, a second semiconductor layer, an active layer located between the first semiconductor layer and the second semiconductor layer, a first conductive layer electrically connected to the first semiconductor layer, a second conductive layer electrically connected to the first conductive layer, and an electrode electrically connected to the second conductive layer, wherein the first conductive layer, the second conductive layer and the electrode together constitute a first electrical connection layer, and further comprising a recess penetrating the first semiconductor layer and the active layer and extending into the interior of the second semiconductor layer, a first insulating layer covering a portion of the surface of the first semiconductor layer and partially exposed to the outside of the light-emitting device, a second insulating layer covering the sidewall of the recess and one side of the first electrical connection layer, a third conductive layer that is mostly in contact with the surface of the second insulating layer and is electrically connected to the second semiconductor layer, and a supporting substrate in contact with the third conductive layer, characterized in that a gap is formed by a groove partially blocked by a lower surface of the first semiconductor layer on the upper surface of the first insulating layer close to the first semiconductor layer. 2 . The light emitting device according to claim 1 , wherein the first conductive layer, the second conductive layer, the third conductive layer and the electrode all comprise a multi-layer metal structure. 3. A light-emitting device according to claim 1, characterized in that when the supporting substrate is a non-conductive material, the third conductive layer is a second electrical connection layer, and when the supporting substrate is conductive, the third conductive layer and the supporting substrate together constitute an electrical connection layer. 4. A method for manufacturing a light emitting device, characterized by comprising: Manufacturing an initial epitaxial structure, including sequentially growing a second semiconductor layer, an active layer, and a first semiconductor layer on an epitaxial growth substrate; Making a recess that penetrates the first semiconductor layer and the active layer and extends into the second semiconductor layer; Producing a first conductive layer on a portion of the surface of the first semiconductor layer; A gap sacrificial layer is formed on the surface of the first semiconductor layer outside the first conductive layer; A first insulating layer is formed on the surface of the first semiconductor layer outside the first conductive layer, wherein the first insulating layer wraps the gap sacrificial layer; Forming a second conductive layer on a portion of the surface of the first insulating layer and on the surface of the first conductive layer; forming a second insulating layer on the remaining surface of the first insulating layer, the surface of the second conductive layer, and the sidewall surface of the recess; forming a third conductive layer on the surface of the second insulating layer; Making a supporting substrate on the surface of the third conductive layer; Etching away the epitaxial growth substrate and a portion of the epitaxial layer consisting of the first semiconductor layer, the active layer and the second semiconductor layer to expose the first insulating layer and a portion of the gap sacrificial layer; The void sacrificial layer is etched away. 5. The method according to claim 4, further comprising: An electrode is formed on a portion of the surface of the second conductive layer. 6. The method according to claim 4, further comprising: The light emitting surface of the second semiconductor layer is roughened.