WO2023087638A1 - Epitaxial structure and manufacturing method, and light-emitting element and manufacturing method - Google Patents

Abstract

The present application provides an epitaxial structure and a manufacturing method, which are simple in manufacturing process and low in cost. The manufacturing method comprises: depositing an N-type material layer on a first substrate, and etching the N-type material layer to form a first protrusion, at least part of the surface of the first protrusion being curved; sequentially depositing a first active layer and a first P-type layer on the first protrusion; removing the first substrate, and etching the side of the N-type material layer away from the first protrusion to form a second protrusion corresponding to the first protrusion, at least part of the surface of the second protrusion being curved; and sequentially depositing a second active layer and a second P-type layer on the second protrusion, the first protrusion and the second protrusion forming an N-type layer, the first active layer and the second active layer forming an active layer, and the first P-type layer and the second P-type layer forming a P-type layer. The present application further provides a method for manufacturing a light-emitting element by using the epitaxial structure and a light-emitting element.

Description

Epitaxial structure and manufacturing method, light-emitting element and manufacturing method technical field

The present application relates to the field of display technology, in particular to an epitaxial structure and a manufacturing method, a light-emitting element and a manufacturing method thereof.

Background technique

In the field of display technology, micron light-emitting diodes (Micro Light-Emitting-Diode, Micro-LED) is a light-emitting pixel unit assembled on the drive panel to form a high-density LED array for display. With the continuous pursuit of lower-sized Micro-LED chips, ensuring their light-emitting area and luminous efficiency has become an urgent problem to be solved. At this time, by making the Micro-LED chip into a spherical shape, the light-emitting area and luminous efficiency of the chip can be improved. However, in the manufacturing process of Micro-LED chips, it is necessary to use special equipment to form a spherical epitaxial layer structure, and the use of special equipment will inevitably increase the complexity and cost of making Micro-LED chips.

technical problem

In the manufacturing process of Micro-LED chips, it is necessary to use special equipment to form a spherical epitaxial layer structure, and the use of special equipment will inevitably increase the complexity and cost of making Micro-LED chips.

technical solution

In view of the above deficiencies in the prior art, the purpose of the present application is to provide an epitaxial structure and its fabrication method, a light-emitting element fabricated on the basis of the epitaxial structure, and a light-emitting element fabrication method thereof.

A method for manufacturing an epitaxial structure, which includes: depositing an N-type material layer on a first substrate, and etching the N-type material layer to form a first protrusion; at least part of the surface of the first protrusion is a curved surface; A first active layer and a first P-type layer are sequentially deposited on a bump; the first substrate is removed, and the side of the N-type material layer away from the first bump is etched to form a layer corresponding to the first bump. The second protrusion; wherein, at least part of the surface of the second protrusion is a curved surface; the second active layer and the second P-type layer are sequentially deposited on the second protrusion; wherein, the first protrusion and the second protrusion The N-type layer is formed together, the first active layer and the second active layer constitute the active layer, and the first P-type layer and the second P-type layer constitute the P-type layer.

Optionally, the first protrusion and the second protrusion are mirror images.

Optionally, the surface of the first protrusion is hemispherical, and the surface of the second protrusion is hemispherical; the first protrusion with the hemispherical surface and the second protrusion with the hemispherical surface combine to form a spherical shape.

Optionally, the step of forming the first protrusions includes: forming first spherical particles on the N-type material layer; and etching the N-type material layer by using the first spherical particles as a mask to form the first protrusions.

Optionally, before removing the first substrate, the method further includes: forming an etching barrier layer on the first P-type layer; wherein, the side of the etching barrier layer away from the first P-type layer is a planarized surface.

Optionally, the step of forming the second protrusion includes: forming second spherical particles on the side of the N-type material layer facing away from the etching barrier layer; using the second spherical particles as a mask for the N-type material layer, the first active layer and the first P-type layer are etched to form a second protrusion; wherein, the end faces of the first active layer and the first P-type layer after etching are flush with the etching barrier layer.

Optionally, before forming the second spherical particles, it also includes: forming a first photoresist layer on the side of the N-type material layer away from the etching barrier layer; patterning the first photoresist layer; The first photoresist layer is a mask, and the N-type material layer, the first active layer, and the first P-type layer are etched to form an island structure corresponding to the first protrusion; wherein, the island structure is along the The length in the direction of extension of the etching barrier layer is at least greater than the length of the first protrusion along the direction of extension of the etching barrier layer; forming second spherical particles on the side of the N-type material layer away from the etching barrier layer is to form a second spherical particle on the island structure particle.

Optionally, the step of forming the second active layer includes: disposing a second photoresist layer on one side of the second protrusion; wherein, the second photoresist layer covers the second protrusion and the end surface of the first active layer and the end surface of the first P-type layer; the second photoresist layer is patterned to expose the end surface of the first active layer and at least part of the second protrusion; at least part of the exposed second protrusion surface and the first An active material layer is deposited on the end surface of the active layer to form a second active layer.

Optionally, the step of forming the second P-type layer includes: removing the second photoresist layer, and disposing a third photoresist layer on one side of the second protrusion; wherein, the third photoresist layer covers the second protrusion The exposed surface of the second active layer and the end face of the first P-type layer; the third photoresist layer is patterned to expose the end face of the first P-type layer and the second active layer; on the exposed second A P-type material layer is deposited on end surfaces of the active layer and the first P-type layer to form a second P-type layer.

Optionally, the step of forming the first insulating layer includes: removing the third photoresist layer, and depositing an insulating material layer on one side of the second protrusion to form the first insulating layer.

Optionally, the step of forming the second insulating layer includes: setting a second substrate on the surface of the first insulating layer;

Removing the etch barrier layer and part of the first insulating layer to expose the end faces of the first P-type layer and the first insulating layer; depositing an insulating material layer on the surface of the first P-type layer and the end faces of the first insulating layer to form a second Two insulating layers.

An embodiment of the present application provides an epitaxial structure, and the epitaxial structure is fabricated by the method of any one of the above-mentioned embodiments.

An embodiment of the present application also proposes a method for manufacturing a light-emitting element, including: providing an epitaxial structure as described above; forming an N electrode and a P electrode on the epitaxial structure; wherein, the N electrode is electrically connected to the N-type layer, and the P The electrodes are electrically connected to the P-type layer.

The present application provides a light emitting element, and the light emitting element is manufactured by using the manufacturing method of the above light emitting element.

Beneficial effect

Compared with the existing technology, the above-mentioned epitaxial structure can use the existing equipment to make spherical N-type layer, active layer, P-type layer and insulating layer, and there is no need to use special equipment to form a spherical epitaxial structure, thereby reducing the cost. Fabrication complexity and cost of spherical epitaxial structures.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic diagram of a three-dimensional structure of an epitaxial structure in an embodiment of the present application.

FIG. 2 is a schematic cross-sectional structure diagram of the epitaxial structure shown in FIG. 1 along any central axis.

3-20 are schematic cross-sectional structure diagrams corresponding to each step in the method for manufacturing the epitaxial structure shown in FIG. 2 .

Fig. 21 is a schematic cross-sectional structure diagram of the light emitting element along any central axis in the first embodiment of the present application.

FIG. 22 is a schematic cross-sectional structure diagram of making an N electrode of the light-emitting element shown in FIG. 21 in the first embodiment of the present application.

23-34 are schematic cross-sectional structural diagrams corresponding to each step in the manufacturing method of the light-emitting element shown in FIG. 21 in the second embodiment of the present application.

FIG. 35 is a schematic cross-sectional structure diagram of a light emitting element in the third embodiment of the present application.

FIG. 36 is a schematic cross-sectional structure diagram of a light emitting element in the fourth embodiment of the present application.

FIG. 37 is a schematic cross-sectional structure diagram of a light emitting element in a fifth embodiment of the present application.

Explanation of reference numerals: 100 - epitaxial structure, O - spherical center, 110 - N-type layer, 111 - first protrusion, 112 - second protrusion, 120 - active layer, 121 - first active layer, 122 -Second active layer, 123-First gap, 130-P-type layer, 131-First P-type layer, 132-Second P-type layer, 133-Second gap, 140-Insulation layer, 141-First Insulation layer, 142-second insulation layer, 150-N electrode, 160-P electrode, 170-current diffusion layer, 180-electron blocking layer, 10-N-type material layer, 20-first substrate, 30-first Spherical particle, 40-etch stop layer, 60-second spherical particle, 001-symmetry line, 70-second photoresist layer, 80-third photoresist layer, 90-second substrate, 200-light-emitting element, H1—the first opening, the end face F1 of the first active layer, the end face F2 of the first P-type layer, and the end face F3 of the first insulating layer.

Detailed ways

In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Preferred embodiments of the application are shown in the accompanying drawings. However, the present application can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terminology used herein in the description of the application is only for the purpose of describing specific embodiments, and is not intended to limit the application.

The present application provides an epitaxial structure 100 , please refer to FIG. 1 . FIG. 1 is a three-dimensional schematic diagram of the epitaxial structure 100 of the present application. As shown in FIG. 1 , the epitaxial structure 100 is spherical and has a center O. The center O is the intersection point of all central axes of the epitaxial structure 100 of the present application.

Please refer to FIG. 2 . FIG. 2 is a schematic cross-sectional structure diagram of the epitaxial structure 100 shown in FIG. 1 along any central axis. In the embodiment shown in FIG. 2 , the epitaxial structure 100 includes an N-type layer 110 , an active layer 120 , a P-type layer 130 , and an insulating layer stacked in sequence from the center O to the outer surface (that is, the outline of the epitaxial structure 100 ). 140.

As shown in FIG. 2 , the N-type layer 110 is a solid spherical structure, including a center O. It can be understood that the center O of the N-type layer 110 is the center O of the epitaxial structure 100 . The active layer 120 is a spherical layer located between the N-type layer 110 and the P-type layer 130 .

In this embodiment, the active layer 120 completely covers the N-type layer 110 and is completely covered by the P-type layer 130 . The insulating layer 140 is a spherical layer that completely covers the P-type layer 130 . The insulating layer 140 can be made of SiO2 or Si3N4 material, which is not specifically limited in this embodiment.

The insulating layer 140 can protect the insulation among multiple epitaxial structures 100 , between the epitaxial structures 100 and the outside world, and between the internal structures of the epitaxial structures 100 .

The present application also provides a method for fabricating the epitaxial structure 100 shown in FIG. 1 , please refer to FIG. 3-FIG. 20 , which are the details of each step in the fabrication of the epitaxial structure 100 shown in FIG. 2 in the first embodiment of the present application. Schematic diagram of the cross-sectional structure. As shown in FIGS. 3-20 , the fabrication of the epitaxial structure 100 includes steps: step 100, depositing an N-type material layer on the first substrate, etching the N-type material layer to form a first protrusion, and the first protrusion At least part of the surface is curved.

Step 100 specifically includes: Step S001 , please refer to FIG. 3 , which is a schematic cross-sectional structure diagram after growing an N-type material layer on the substrate.

As shown in FIG. 3 , a first substrate 20 is provided, and metal-organic compound vapor deposition (Metal-organic The N-type material layer 10 is grown by Chemical Vapor Depodition (MOCVD). The material of the N-type material layer 10 may be aluminum gallium indium phosphide (AlGaInP) or other materials, which are not specifically limited in this application.

The material of the first substrate 20 may be materials such as sapphire, quartz or ceramics. In the embodiment shown in FIG. 3 , the first substrate 20 is made of sapphire.

Step S002 , please refer to FIG. 4 . FIG. 4 is a schematic cross-sectional structure diagram of making the first protrusion 111 . As shown in Figure 4, the first spherical particles 30 are produced on the surface of the N-type material layer 10 away from the first substrate 20, and the N-type material layer 10 is etched with the first spherical particles 30 as a mask to obtain the first A protrusion 111, at least part of the surface of the first protrusion 111 is a curved surface.

The etching can be wet etching, dry etching, etc. In this embodiment, the N-type material layer 10 can be etched by dry etching.

The first spherical particles 30 can be made by spin coating or other methods, which is not specifically limited in this embodiment.

In the embodiment shown in FIG. 4, the first spherical particles 30 are formed by spin coating. In addition, the curved surface shape of the first protrusion 111 may be an ellipse curved surface, a spherical curved surface, etc. In this embodiment, the first protrusion 111 is a hemisphere whose curved surface shape is a specific spherical curved surface.

Step 200 , sequentially depositing and forming a first active layer and a first P-type layer on the first protrusion 111 .

Wherein, step 200 specifically includes: step S003 , please refer to FIG. 5 , which is a schematic cross-sectional structure diagram of forming the first active layer 121 and the first P-type layer 131 .

As shown in Figure 5, after the first spherical particles 30 are removed, a layer of active material and a layer of P-type material are sequentially grown on the surface of the first protrusion 111 and the surface of the N-type material layer 10 by MOCVD method, so as to The first active layer 121 and the first P-type layer 131 are formed, wherein the deposition thicknesses of the first active layer 121 and the first P-type layer 131 can be the same, or can be adjusted according to needs, which is not specifically limited in this application.

In the embodiment shown in FIG. 5 , the deposition thicknesses of the first active layer 121 and the first P-type layer 131 are substantially the same. The first active layer 121 covers the first protrusion 111 and the planarized surface of the N-type material layer 10 , corresponding to the first active layer 121 having a spherical layer structure covering the spherical surface of the first protrusion 111 .

The first P-type layer 131 covers the first active layer 121 , so the first P-type layer 131 has a spherical surface corresponding to the spherical layer structure of the first active layer 121 , ie has a spherical layer structure.

Among them, the material of the active material layer can be aluminum gallium indium phosphide series, aluminum gallium indium nitride series, zinc oxide series, and its structure can be single heterostructure, double heterostructure, double-sided heterostructure, multilayer Quantum wells, etc., the material of the P-type material layer may be gallium phosphide, and this embodiment does not specifically limit the material and structure of the active material layer and the P-type material layer.

Step S004 , please refer to FIG. 6 . FIG. 6 is a schematic cross-sectional structure diagram after forming an etch stop layer (Etch Stop Layer, ESL) 40 . As shown in FIG. 6 , an etch stop layer 40 is deposited on the surface of the first P-type layer 131 away from the first substrate 20 , and the surface of the etch stop layer 40 away from the first P-type layer 131 is a planarized surface.

Wherein, the etching stopper layer 40 may use SiC material or other silicon-containing materials, and the embodiment of the present application does not specifically limit the material of the etching stopper layer 40 .

In step 300, the first substrate 20 is removed, and the side of the N-type material layer 10 facing away from the first protrusion 111 is etched to form a second protrusion corresponding to the first protrusion 111, wherein the second protrusion At least part of the surface is curved.

Step 300 specifically includes: Step S005 , please refer to FIG. 7 , which is a schematic cross-sectional structure diagram after removing the first substrate 20 .

In the embodiment shown in FIG. 7 , the positions of the first substrate 20 and the etch stop layer 40 in three-dimensional space are exchanged, and the first substrate 20 is stripped and removed.

That is, the surface of the N-type material layer 10 facing away from the first protrusion 111 is exposed to facilitate subsequent processes.

Step S006 , please refer to FIG. 8 . FIG. 8 is a schematic cross-sectional structure diagram of forming an island structure corresponding to the first protrusion 111 . As shown in FIG. 8, a first photoresist layer (not shown in the figure) is formed on the surface of the N-type material layer 10 away from the etching barrier layer 40, and the first photoresist layer is patterned so that the first light The resistance layer includes a first preset pattern (not shown in the figure).

Etching the N-type material layer 10, the first active layer 121 and the first P-type layer 131 with the first photoresist layer containing the first preset pattern as a mask to form a island structure. Wherein, the length of the island structure along the extending direction of the etching barrier layer 40 is at least greater than the length of the first protrusion 111 along the extending direction of the etching barrier layer 40 .

In this embodiment, the island structure corresponding to the first protrusion 111 is that the first protrusion 111 extends from a hemispherical structure to a spherical structure, and the first active layer 121 and the first P-type layer 131 develop from a hemispherical layer to a spherical structure. The structure after the layer structure is extended.

After the island structure corresponding to the first protrusion 111 is formed, the first photoresist layer is peeled off.

Step S007 , please refer to FIG. 9 , which is a schematic cross-sectional structure diagram of the second protrusion 112 . As shown in FIG. 9 , the etching is continued on the N-type material layer 10 , the first active layer 121 and the first P-type layer 131 .

Specifically, the second spherical particles 60 are formed on the island structure, that is, the second spherical particles 60 are formed on the surface of the N-type material layer 10 away from the etch stop layer 40. The method of manufacturing the second spherical particles 60 in this embodiment Not specifically limited.

The N-type material layer 10 , the first active layer 121 and the first P-type layer 131 are etched by using the second spherical particle 60 as a mask to form the second protrusion 112 with a curved shape.

Wherein, the curved surface shape of the second protrusion 112 may be an ellipse curved surface, a spherical curved surface, etc. In this embodiment, the second protrusion 112 is a hemisphere whose curved surface shape is a specific spherical curved surface.

Further, as shown in FIG. 9, the second protrusion 112 and the first protrusion 111 are mirror-symmetrical about the symmetry line 001, and the second protrusion 112 and the first protrusion 111 are combined to form an N-type layer 110, and the N-type layer 110 The whole is a spherical structure, and its surface profile is a spherical shape. The line of symmetry 001 is the central axis of symmetry of the first protrusion 111 and the second protrusion 112 .

In addition, the end faces formed after the first active layer 121 and the first P-type layer 131 are etched are flush with the etch stop layer 40, that is, the end face F1 of the first active layer 121 and the end face of the first P-type layer 131 The end face F2 is flush with the etch stop layer 40 .

Step 400, sequentially depositing a second active layer and a second P-type layer on the second bumps, the first bumps 111 and the second bumps 112 constitute the N-type layer 110, the first active layer 121 and the second The active layer constitutes the active layer, and the first P-type layer 131 and the second P-type layer constitute the P-type layer.

Step 400 specifically includes: Step S008 , please refer to FIG. 10 , FIG. 10 is a schematic cross-sectional structure diagram of the second photoresist layer 70 after patterning.

As shown in FIG. 10, after removing the second spherical particles 60 shown in FIG. A second photoresist layer 70 is disposed on the surface of the etching barrier layer 40 .

The second photoresist layer 70 is patterned, that is, the second photoresist layer 70 is exposed and developed. After exposure and development, the second photoresist layer 70 covers the surface of the etching stopper layer 40 and the end face F2 of the first P-type layer 131, and exposes part of the surface of the N-type layer 110 and the first active layer 121, that is, Part of the spherical surface of the second protrusion 112 and the end surface F1 of the first active layer 121 are exposed.

In the embodiment shown in FIG. 10 , the entire spherical surface of the second protrusion 112 and the end surface F1 of the first active layer 121 are exposed after the second photoresist layer 70 is exposed and developed.

Step S009 , please refer to FIG. 11 . FIG. 11 is a schematic cross-sectional structure diagram of forming the second active layer 122 . A layer of active layer material can be deposited on the exposed spherical surface of the second protrusion 112, the end face F1 of the first active layer 121, and the surface of the second photoresist layer 70 by MOCVD method to obtain the second active layer 122.

Wherein, the deposition thickness of the second active layer 122 may be the same as that of the first active layer 121 .

As shown in Figure 11, the second active layer 122 covers the end face F1 of the first active layer 121, the spherical surface of the second protrusion 112 and the surface of the second photoresist layer 70, then the second active layer 122 is corresponding to A spherical layer having substantially the same structure and size as the end surface F1 of the first active layer 121 is formed on the spherical surface of the second protrusion 112 .

In this embodiment, the second active layer 122 is a hemispherical layer with a spherical surface, and the second active layer 122 is mirror-symmetrical to the first active layer 121 about the symmetry line 001 .

Further, the second active layer 122 is combined with the first active layer 121 to form the active layer 120 , and the active layer 120 is a spherical layer covering the N-type layer 110 .

Step S010 , please refer to FIG. 12 . FIG. 12 is a schematic cross-sectional structure diagram after peeling off the second photoresist layer 70 . As shown in FIG. 12 , the second photoresist layer 70 and the active layer material layer covering the surface of the second photoresist layer 70 are peeled off. And the surface of the etching stopper layer 40 , the surface of the second active layer 122 and the end surface F2 of the first P-type layer 131 are exposed.

Step S011 , please refer to FIG. 13 , which is a schematic cross-sectional structure diagram of the third photoresist layer 80 after patterning. As shown in Figure 13, the third photoresist layer 80 is coated on the surface of the etching barrier layer 40, the surface of the second active layer 122 and the end face F2 of the first P-type layer 131, and the third photoresist layer 80 is patterned processing.

In the embodiment shown in FIG. 13 , the third photoresist layer 80 is exposed and developed, so that the third photoresist layer 80 covers the surface of the etching barrier layer 40 and reveals the spherical surface of the second active layer 122 and the end face F2 of the first P-type layer 131 .

Step S012 , please refer to FIG. 14 , which is a schematic cross-sectional structure diagram of forming the second P-type layer 132 . In the embodiment shown in FIG. 14, a P-type layer can be deposited on the spherical surface of the second active layer 122, the end face F2 of the first P-type layer 131, and the surface of the third photoresist layer 80 by MOCVD method. material layer.

As shown in FIG. 14 , the P-type material layer covering the spherical surface of the second active layer 122 and the end face F2 of the first P-type layer 131 forms the second P-type layer 132, that is, the second P-type layer 132 has a spherical shape. The spherical layer on the surface, and the size of the end face of the spherical layer is basically the same as the shape and size of the end face F2 of the first P-type layer 131 .

In this embodiment, the first P-type layer 131 and the second P-type layer 132 are mirror-symmetrical about the symmetry line 001, and the first P-type layer 131 and the second P-type layer 132 are combined to form the P-type layer 130, and the P-type layer 130 It is a spherical layer covering the active layer 120 .

Step S013 , please refer to FIG. 15 . FIG. 15 is a schematic cross-sectional structure diagram after peeling off the third photoresist layer 80 . As shown in FIG. 15, the third photoresist layer 80 and the P-type material layer deposited on the surface of the third photoresist layer 80 as shown in FIG. 14 are peeled off to reveal part of the surface of the P-type layer 130 and the etching barrier 40 , that is, the spherical surface exposing the second P-type layer 132 and the flat surface of the etch stop layer 40 .

Step S014 , please refer to FIG. 16 , which is a schematic cross-sectional structure diagram of forming the first insulating layer 141 . An insulating material layer is deposited on the surface of the second P-type layer 132 and the surface of the etch stop layer 40 . As shown in FIG. 16 , the insulating material layer covering the spherical surface of the second P-type layer 132 forms a spherical surface with the same shape as the second P-type layer 132 , that is, the first insulating layer 141 .

In this embodiment, the first insulating layer 141 is a spherical layer with a spherical surface, and the size of the end face F3 (see FIG. 18 ) of the first insulating layer 141 can be basically the same as the shape and size of the end face of the P-type layer 130. The embodiment does not limit this.

Step S015 , please refer to FIG. 17 , which is a schematic cross-sectional structure diagram after the second substrate 90 is set. The second substrate 90 is disposed on the spherical surface formed of the first insulating layer 141 and the surface of the insulating material layer deposited on the etch stop layer 40 . As shown in FIG. 17 , the surface of the second substrate 90 facing away from the etch stop layer 40 may be a planarized surface.

Step S016 , please refer to FIG. 18 . FIG. 18 is a schematic diagram of a cross-sectional structure after peeling off the etching stopper layer 40 .

The etch stop layer 40 and the second substrate 90 are exchanged in three-dimensional space, and the etch stop layer 40 and the insulating material layer deposited on the etch stop layer 40 are stripped off. As shown in FIG. 18 , the surface of the second substrate 90 , the end face F3 of the first insulating layer 141 and the surface of the first P-type layer 131 are exposed to facilitate subsequent processes.

Step S017 , please refer to FIG. 19 , which is a schematic cross-sectional structure diagram of forming the second insulating layer 142 . An insulating material layer is deposited on the surface of the second substrate 90 , the surface of the first P-type layer 131 and the end surface F3 of the first insulating layer 141 , and the insulating material layer deposited on the surface of the second substrate 90 is peeled off.

As shown in FIG. 19, the insulating material layer deposited on the surface of the first P-type layer 131 forms a second insulating layer 142 covering the first P-type layer 131, that is, the second insulating layer 142 is a spherical layer with a spherical surface, Moreover, the shape and size of the end surface of the spherical layer of the second insulating layer 142 are substantially the same as the shape and size of the end surface F3 of the first insulating layer 141 .

In this implementation, the first insulating layer 141 cooperates with the second insulating layer 142 to form the insulating layer 140 , and the insulating layer 140 covers the P-type layer 130 to form a spherical layer structure.

Step S018 , please refer to FIG. 20 . FIG. 20 is a schematic cross-sectional structure diagram after peeling off the second substrate 90 . As shown in FIG. 20 , the second substrate 90 is peeled off from the surface of the first insulating layer 141 as shown in FIG. 19 to obtain the epitaxial structure 100 as shown in FIG. 2 .

The aforementioned epitaxial structure 100 can completely use existing equipment to make spherical N-type layer 110, active layer 120, P-type layer 130, and insulating layer 140, and there is no need to use special equipment to form spherical epitaxial structure 100, thereby reducing the spherical shape. Fabrication complexity and cost of the epitaxial structure 100 .

The present application also provides a light emitting element 200. In this embodiment, the light emitting element 200 is formed by forming an N electrode and a P electrode respectively on the epitaxial structure 100 shown in FIG. 2 .

Wherein, the N electrode is electrically connected to the N-type layer, the P electrode is electrically connected to the P-type layer, and the N-electrode and the P-electrode externally receive a driving signal so that the N-type layer and the P-type layer drive the active layer to emit light.

Specifically, as shown in FIG. 21 , where FIG. 21 is a schematic cross-sectional structure diagram of a light-emitting element 200 along any central axis, the light-emitting element 200 is obtained by fabricating an N electrode 150 and a P electrode 160 respectively on the basis of the epitaxial structure 100 of the present application. . Wherein, the N electrode 150 is connected to the N-type layer 110 , and the P electrode 160 is connected to the P-type layer 130 .

The present application also provides a method for fabricating a light-emitting element 200 as shown in FIG. 21 , specifically, further manufacturing the N electrode 150 and the P electrode 160 on the basis of the epitaxial structure 100 to obtain the light-emitting element 200 .

As shown in FIG. 22 , it is a schematic cross-sectional structure corresponding to each step in the manufacturing method of the light-emitting element shown in FIG. 21 in the first embodiment of the present application. In this embodiment, the N electrode is fabricated on the basis of the epitaxial structure 100 150 and P electrode 160 to obtain the light-emitting element 200 includes: through the aforementioned steps S001-S017 of making the epitaxial structure 100, the N-type layer 110, active layer 120, P-type layer 130 and insulating layer of the light-emitting element 200 of the present application can be fabricated 140.

Step S019 , please refer to FIG. 22 . FIG. 22 is a schematic cross-sectional structure diagram of the fabricated N electrode 150 . A first opening H1 is formed on the insulating layer 140 , the first opening H1 penetrates to the surface of the N-type layer 110 , and an N electrode 150 is disposed inside the first opening H1 .

Wherein, a layer of insulating material is attached to the inner wall of the first opening H1 for insulation between the N electrode 150 and other structures. In this embodiment, the material of the insulating material attached to the inner wall of the first opening H1 is not specifically limited. In the illustrated embodiment, the insulating material and the insulating layer 140 are made of the same material.

Specifically, a Si3N4 cover film or the like can be used as a mask on the surface of the insulating layer 140, and at the same time, chlorine plasma reactive ion etching is used to etch the insulating layer 140 until the surface of the N-type layer 110 is exposed to make the first opening. H1. An N electrode 150 that may be formed of a Ni/Au vapor-deposited film is disposed inside the first opening H1 , and the manufacturing method of the N electrode 150 is not specifically limited in this embodiment.

Further, this embodiment does not specifically limit the structural shape, position, material, etc. of the N electrode 150 . It can be understood that the first opening H1 and the N electrode 150 can be in the form of a long and thin strip or a square structure, etc., and are arranged along any central axis direction of the spherical outline of the light emitting element 200. The N electrode 150 makes the current flow on the N-type layer 110 Diffuses evenly without blocking light.

After the N electrode 150 is formed, the Si3N4 capping film is removed.

Step S020 , please refer to FIG. 21 . FIG. 21 is a schematic cross-sectional structure diagram of the fabricated P electrode 160 . As shown in FIG. 21 , a P-electrode 160 in ohmic contact with the P-type layer 130 is formed on the insulating layer 140 at a certain distance from the N-electrode 150 .

Specifically, in the embodiment shown in FIG. 21 , on the surface of the insulating layer 140 opposite to the N electrode 150 , a Ti/Au evaporated film is used to form a P electrode 160 in contact with the surface of the P type layer 130 .

The present application does not specifically limit the structural shape and position of the P electrode. In the embodiment shown in FIG. 21 , the orthographic projection of the P electrode 160 on a plane perpendicular to the central axis where the N electrode 150 is located is linear.

The N electrode 150 cooperates with the P electrode 160 to form a conductive path between the N-type layer 110 and the P-type layer 130, that is, the N-type layer 110, the active layer 120 and the P-type layer 130 are coordinated under the drive of the current in the power supply. Outgoing rays.

The light-emitting element 200 fabricated on the basis of the foregoing epitaxial structure 100 is not only relatively low in manufacturing complexity and cost, but also has a larger light-emitting area in the active layer 120 of the spherical layer, thereby effectively improving the light-emitting efficiency of the light-emitting element 200 .

Please refer to FIGS. 23-34 , which are schematic cross-sectional structure diagrams corresponding to each step in the manufacturing method of the light-emitting element shown in FIG. 21 in the second embodiment of the present application. In this embodiment, N The steps of obtaining the light-emitting element 200 from the electrode 150 and the P electrode 160 include: through the steps S001-S007 of making the epitaxial structure 100 described above, the N-type layer 110, the first active layer 121, and the second active layer 121 of the light-emitting element 200 of the present application can be fabricated. A P-type layer 131 .

Step S021 , please refer to FIG. 23 , which is a schematic cross-sectional structure diagram of the second photoresist layer 70 after patterning. As shown in FIG. 23 , the second photoresist layer 70 is disposed on the exposed surface of the N-type layer 110 , the exposed surface of the first active layer 121 , the exposed surface of the first P-type layer 131 and the surface of the etching barrier layer 40 . And the second photoresist layer 70 is patterned, that is, the second photoresist layer 70 is exposed and developed.

After exposure and development, the second photoresist layer 70 covers the surface of the etch stop layer 40 and the end surface of the first P-type layer 131, and exposes part of the surface of the N-type layer 110 and the first active layer 121, that is, exposes the first P-type layer 131. The partially spherical surface of the two protrusions 112 and the end surface of the first active layer 121 .

In the embodiment shown in FIG. 23 , the second photoresist layer 70 is exposed and developed to expose part of the surface of the second protrusion 112 and the end surface of the first active layer 121 .

Step S022 , please refer to FIG. 24 , which is a schematic cross-sectional structure diagram of the second active layer 122 formed. A layer of active layer material can be deposited on the partially exposed spherical surface of the second protrusion 112, the end face of the first active layer 121 and the surface of the second photoresist layer 70 by MOCVD method to obtain the second active layer 122, and the deposition thickness of the second active layer 122 is the same as that of the first active layer 121.

As shown in Figure 24, the second active layer 122 covers the end surface of the first active layer 121, the spherical surface of the exposed second protrusion 112 and the planarized surface of the second photoresist layer 70, so the second active layer 122 The layer 122 forms a spherical layer having the same size as the end surface of the first active layer 121 on the spherical surface corresponding to the second protrusion 112 .

At this time, since part of the second photoresist layer 70 is provided on the surface of the second protrusion 112, the second active layer 122 has a first gap 123, and part of the surface of the N-type layer 110 is exposed from the first gap 123. For example, the position, shape and structure of the first notch 123 are not specifically limited.

It can be understood that the second active layer 122 is a hemispherical layer with a spherical surface, and the second active layer 122 is mirror-symmetrical to the first active layer 121 about the symmetry line 001 .

Further, the second active layer 122 is combined with the first active layer 121 to form the active layer 120 , and the active layer 120 is a spherical layer covering the N-type layer 110 . It can be understood that the active layer 120 has a first gap 123 .

Step S023 , please refer to FIG. 25 . FIG. 25 is a schematic cross-sectional structure diagram after peeling off part of the second photoresist layer 70 . As shown in FIG. 25, the second photoresist layer 70 and the active layer material layer covering the surface of the second photoresist layer 70 are peeled off, so that the surface of the barrier layer 40, the surface of the second active layer 122, the first P The end surface of the N-type layer 131 is exposed, and part of the surface of the N-type layer 110 is exposed through the first gap 123 .

Step S024 , please refer to FIG. 26 , which is a schematic cross-sectional structure diagram of the third photoresist layer 80 after patterning. As shown in FIG. 26, the surface of the etching barrier layer 40, the surface of the second active layer 122, the end surface of the first P-type layer 131, and the part of the surface of the N-type layer 110 exposed from the first gap 123 are coated with a third photoconductive layer. resist layer 80, and pattern the third photoresist layer 80.

In the embodiment shown in FIG. 13 , the third photoresist layer 80 is exposed and developed, so that the third photoresist layer 80 covers the etching stopper layer 40 and part of the surface of the N-type layer 110 exposed at the first gap 123 , and expose the surface of the second active layer 122 and the end surface of the first P-type layer 131 .

Step S025 , please refer to FIG. 27 , which is a schematic cross-sectional structure diagram of forming the second P-type layer 132 . In the embodiment shown in FIG. 27 , a P-type material layer can be deposited on the exposed spherical surface of the second active layer 122, the end face of the first P-type layer 131 and the surface of the third photoresist layer 80 by MOCVD method. .

As shown in Figure 27, the P-type material layer covering the spherical surface of the second active layer 122 and the end face of the first P-type layer 131 forms the second P-type layer 132, that is, the second P-type layer 132 has a spherical surface The spherical layer, and the size of the end surface of the spherical layer is the same as the size of the end surface of the first P-type layer 131 .

Furthermore, because part of the third photoresist layer 80 is provided on the surface of the N-type layer 110 exposed from the first gap 123 , the second P-type layer 132 has a second gap 133 . And as shown in FIG. 27 , the shape, size and position of the second notch 133 correspond to the first notch 123 .

It can be understood that the first P-type layer 131 and the second P-type layer 132 are mirror-symmetrical about the symmetry line 001, and the first P-type layer 131 and the second P-type layer 132 are combined to form the P-type layer 130, and the P-type layer 130 is The spherical layer covering the active layer 120, and the P-type layer 130 has a second gap 133, and the second gap 133 and the first gap 123 combine to form the first opening H1.

Step S026 , please refer to FIG. 28 . FIG. 28 is a schematic cross-sectional structure diagram after peeling off the third photoresist layer 80 . As shown in FIG. 28, the third photoresist layer 80 and the P-type material layer deposited on the surface of the third photoresist layer 80 are peeled off to expose the surface of the second P-type layer 132, the surface of the etching barrier layer 40, and the N part of the surface of the type layer 110. Wherein, part of the surface of the N-type layer 110 is exposed from the first opening H1.

Step S027 , please refer to FIG. 29 , which is a schematic cross-sectional structure diagram of forming the first insulating layer 141 . A layer of insulating material is deposited on the surface of the second P-type layer 132 , the partially exposed surface of the N-type layer 110 , and the surface of the etching barrier layer 40 .

As shown in FIG. 29 , the insulating material layer covering the spherical surface of the second P-type layer 132 will form a spherical surface with the same shape as the second P-type layer 132 , that is, the first insulating layer 141 .

It can be understood that the first insulating layer 141 is a spherical layer with a spherical surface, and its end surface size may be the same as that of the P-type layer 130 , and may be adjusted as required, which is not limited in this embodiment.

In addition, as shown in FIG. 29 , the insulating material layer also covers the end surface of the second active layer 122 at the first gap 123 and the end surface of the second P-type layer 132 at the second gap 133 . It can be understood that a layer of insulating material is attached to the inner wall of the first opening H1.

Step S028 , please refer to FIG. 30 , which is a schematic cross-sectional structure diagram of the fabricated N electrode 150 . As shown in FIG. 30, an N electrode 150 is formed in the first opening H1. Specifically, the insulating layer material covering part of the surface of the N-type layer 110 is removed to expose part of the surface of the N-type layer 110 from the first opening H1, wherein the method of removing the insulating layer material can be by etching or other methods. There is no specific limit to the application.

On the surface of the exposed N-type layer 110 and inside the first opening H1 , an N-electrode 150 that may be formed of a Ni/Au vapor-deposited film is provided, so that the N-electrode 150 is connected to the N-type layer 110 .

It can be understood that, since the inner wall of the first opening H1 is covered with a layer of insulating material, the side of the N electrode 150 adjacent to the inner wall of the first opening H1 is wrapped by the insulating material layer, so that the N electrode 150 and the active layer 120, The P-type layers 130 are insulated. In this embodiment, the manufacturing method and material of the N electrode 150 are not specifically limited.

Further, in the embodiment shown in FIG. 30 , the surface of the N electrode 150 away from the etch stop layer 40 and the surface of the first insulating layer 141 form a complete hemispherical profile.

Step S029 , please refer to FIG. 31 , which is a schematic cross-sectional structure diagram of setting the second substrate 90 . As shown in FIG. 31 , a second substrate 90 is provided on the surface of the first insulating layer 141 .

Wherein, the second substrate 90 completely covers the first insulating layer 141 and the surface of the N electrode 150 facing away from the etching barrier layer 40 , and the surface of the second substrate 90 facing away from the etching barrier layer 40 is a planarized surface.

It can be understood that the second substrate 90 may be made of materials such as sapphire, quartz or ceramics, which is not specifically limited in this embodiment.

Step S030 , please refer to FIG. 32 , which is a schematic diagram of a cross-sectional structure after removing the etching stopper layer 40 . In the embodiment shown in FIG. 32 , the positions of the etch stop layer 40 and the second substrate 90 in the space are exchanged, that is, the planarized surface of the etch stop layer 40 is exposed. And use the solution corresponding to the etching stopper layer 40 and the insulating material layer used in this embodiment to respectively remove the etching stopper layer 40 and the insulating material layer covering the surface of the etching stopper layer 40, so that the second substrate 90 The surface adjacent to the etch stop layer 40 is exposed, and the end face F3 of the first insulating layer 141 is exposed.

Step S031 , please refer to FIG. 33 , which is a schematic cross-sectional structure diagram of forming the second insulating layer 142 . An insulating material layer is deposited on the exposed surface of the second substrate 90 , the surface of the first P-type layer 131 and the end surface of the first insulating layer 141 , and the insulating material layer deposited on the surface of the second substrate 90 is peeled off.

As shown in FIG. 33, the insulating material layer deposited on the surface of the first P-type layer 131 forms the second insulating layer 142 covering the first P-type layer 131, that is, the second insulating layer 142 is a spherical layer with a spherical surface, And the size of the end surface of the spherical layer of the second insulating layer 142 is the same as that of the first insulating layer 141 .

It can be understood that the first insulating layer 141 and the second insulating layer 142 are combined to form the insulating layer 140 , and the insulating layer 140 is a spherical layer covering the P-type layer 130 .

Step S032 , please refer to FIG. 34 , which is a schematic cross-sectional structure diagram of the fabricated P electrode 160 . A P electrode 160 in ohmic contact with the P type layer 130 is formed on the insulating layer 140 at a certain distance from the N electrode 150 .

Specifically, in the embodiment shown in FIG. 34 , on the surface of the insulating layer 140 opposite to the N electrode 150, a Ti/Au vapor-deposited film is used to form a P electrode 160 in contact with the surface of the P-type layer 130. The P electrode The orthographic projection of 160 on a plane perpendicular to the central axis where the N-electrode 150 is located is a line.

Please refer to FIG. 35 , which is a schematic cross-sectional structure diagram of the light emitting element shown in FIG. 21 in the third embodiment of the present application. As shown in FIG. 35 , the structure of the light emitting element 200 in this embodiment is basically the same as that of the light emitting element 200 shown in FIG. 21 , the only difference being the structure and position of the P electrode 160 .

Specifically, in the embodiment shown in FIG. 35 , the orthographic projection of the P-electrode 160 on a plane perpendicular to the central axis of the N-electrode 150 is a closed ring shape, which can make the current spread on the P-type layer 130 more uniform without Block out the light. That is, the luminous efficiency of the light emitting element 200 is not affected.

Alternatively, the number and position of the P electrodes 160 can be adjusted according to actual needs.

Please refer to FIG. 36 . FIG. 36 is a schematic cross-sectional structure diagram of a light emitting element 200 in the fourth embodiment of the present application. As shown in FIG. 36 , the light emitting element 200 may further include a current spreading layer 170 . The current spreading layer 170 is located between the P-type layer 130 and the insulating layer 140 , and its structure is a spherical layer covering the P-type layer 130 . It can be understood that the current spreading layer 170 can make the current spread and distribute evenly on the P-type layer 130 .

Please refer to FIG. 37 . FIG. 37 is a schematic cross-sectional structure diagram of a light emitting element 200 in the fourth embodiment of the present application. As shown in FIG. 37 , the light emitting element 200 may further include an electron blocking layer 180 . The electron blocking layer 180 is a spherical layer located between the active layer 120 and the P-type layer 130 and can cover the active layer 120 .

It can be understood that electron migration can be blocked by the electron blocking layer 180 to avoid reduction of the luminous efficiency of the active layer 120 , that is, the electron blocking layer 180 can enhance the luminous efficiency of the light emitting element 200 .

Alternatively, the current diffusion layer 170 and the electron blocking layer 180 can be adjusted according to actual needs, that is, the current diffusion layer 170 or the electron blocking layer 180 can be provided separately, or the current diffusion layer 170 and the electron blocking layer 180 can be provided at the same time. There is no specific limitation on this example.

The above is only a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Any person familiar with the technical field can easily think of various equivalents within the technical scope disclosed in the application. The modifications or replacements should be covered by the scope of protection of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (14)

A method for fabricating an epitaxial structure, comprising: Depositing an N-type material layer on the first substrate, etching the N-type material layer to form a first protrusion; at least part of the surface of the first protrusion is a curved surface; sequentially depositing and forming a first active layer and a first P-type layer on the first protrusion; removing the first substrate, and etching the side of the N-type material layer away from the first protrusion to form a second protrusion corresponding to the first protrusion; wherein, the first 2. At least part of the surface of the protrusion is curved; A second active layer and a second P-type layer are sequentially deposited on the second protrusions; wherein, the first protrusions and the second protrusions form an N-type layer, and the first active layer and the second The two active layers constitute the active layer, and the first P-type layer and the second P-type layer constitute the P-type layer. The method for fabricating an epitaxial structure according to claim 1, wherein the first protrusion and the second protrusion are mirror-image symmetrical. The method for fabricating an epitaxial structure according to claim 2, wherein the surface of the first protrusion is hemispherical, the surface of the second protrusion is hemispherical; the first protrusion having a hemispherical surface Combined with the second protrusion having a hemispherical surface to form a spherical shape. The method for manufacturing an epitaxial structure according to claim 1, wherein the step of forming the first protrusion comprises: forming first spherical particles on the N-type material layer; Etching the N-type material layer by using the first spherical particle as a mask to form the first protrusion. The method for manufacturing an epitaxial structure according to claim 1, wherein, before removing the first substrate, further comprising: An etching barrier layer is formed on the first P-type layer; wherein, the side of the etching barrier layer away from the first P-type layer is a planarized surface. The method for manufacturing an epitaxial structure according to claim 5, wherein the step of forming the second protrusion comprises: forming second spherical particles on the side of the N-type material layer away from the etching barrier layer; Etching the N-type material layer, the first active layer, and the first P-type layer by using the second spherical particles as a mask to form the second protrusion; wherein, the first active layer, The end face formed after etching of the first P-type layer is flush with the etching barrier layer. The method for manufacturing an epitaxial structure according to claim 6, wherein, before said forming the second spherical particles, further comprising: forming a first photoresist layer on the side of the N-type material layer away from the etching barrier layer; patterning the first photoresist layer; Using the patterned first photoresist layer as a mask, etch the N-type material layer, the first active layer, and the first P-type layer to form An island-shaped structure; wherein, the length of the island-shaped structure along the extending direction of the etching barrier layer is at least greater than the length of the first protrusion along the extending direction of the etching barrier layer; The forming of the second spherical particles on the side of the N-type material layer facing away from the etching barrier layer is to form the second spherical particles on the island structure. The method for manufacturing an epitaxial structure according to claim 6, wherein the step of forming the second active layer comprises: A second photoresist layer is disposed on one side of the second protrusion; wherein, the second photoresist layer covers the second protrusion, the end surface of the first active layer and the first P-type the end face of the layer; patterning the second photoresist layer to expose the end surface of the first active layer and at least part of the second protrusion; An active material layer is deposited on at least part of the exposed second protruding surface and the end surface of the first active layer to form a second active layer. The method for manufacturing an epitaxial structure according to claim 8, wherein the step of forming the second P-type layer comprises: removing the second photoresist layer, and disposing a third photoresist layer on one side of the second protrusion; wherein, the third photoresist layer covers the exposed surface of the second protrusion, the first Two active layers and the end faces of the first P-type layer; patterning the third photoresist layer to expose the end face of the first P-type layer and the second active layer; A P-type material layer is deposited on the exposed end faces of the second active layer and the first P-type layer to form a second P-type layer. The method for manufacturing an epitaxial structure according to claim 9, said method further comprising: The third photoresist layer is removed, and an insulating material layer is deposited on one side of the second protrusion to form a first insulating layer. The method for manufacturing an epitaxial structure according to claim 10, said method further comprising: setting a second substrate on the surface of the first insulating layer; removing the etch stop layer and part of the first insulating layer to expose the first p-type layer and the end faces of the first insulating layer; An insulating material layer is deposited on the surface of the first P-type layer and the end surface of the first insulating layer to form a second insulating layer. An epitaxial structure, wherein the epitaxial structure is fabricated by the method according to any one of claims 1-11. A method of manufacturing a light emitting element, comprising: providing an epitaxial structure as claimed in claim 12; An N electrode and a P electrode are formed on the epitaxial structure respectively; wherein, the N electrode is electrically connected to the N-type layer, and the P electrode is electrically connected to the P-type layer. A light-emitting element, wherein the light-emitting element is produced by the method as claimed in claim 13.