阅读说明：本技术 一种激光器及其制造方法 (Laser and manufacturing method thereof ) 是由 梁栋 刘嵩 张�成 于 2020-04-15 设计创作，主要内容包括：本发明提出一种激光器,包括：衬底；多个发光单元,设置在所述衬底上。每一所述发光单元上设置第一欧姆金属电极；至少两个支撑单元,设置在所述衬底上,所述至少两个支撑单元通过导电连接层连接,且所述导电连接层连接第二欧姆金属电极；第一绝缘层,设置在所述多个发光单元及所述至少两个支撑单元上,且所述第一绝缘层覆盖部分所述第二欧姆金属电极；至少两个金属柱,分别设置在所述多个发光单元及所述至少两个支撑单元上；其中,所述多个发光单元发射的光线通过所述衬底出射。本发明提出的激光器可以在增强散热能力的同时,省去金线键合步骤。(The invention provides a laser, comprising: a substrate; a plurality of light emitting cells disposed on the substrate. A first ohmic metal electrode is arranged on each light-emitting unit; the at least two supporting units are arranged on the substrate and connected through a conductive connecting layer, and the conductive connecting layer is connected with the second ohmic metal electrode; a first insulating layer disposed on the plurality of light emitting cells and the at least two supporting units, and covering a portion of the second ohmic metal electrode; at least two metal columns respectively arranged on the plurality of light-emitting units and the at least two supporting units; wherein the light emitted by the plurality of light emitting units is emitted through the substrate. The laser provided by the invention can enhance the heat dissipation capability and simultaneously save the gold wire bonding step.)

1. A laser, comprising,

a substrate;

the light-emitting units are arranged on the substrate, and each light-emitting unit is provided with a first ohmic metal electrode;

the at least two supporting units are arranged on the substrate and connected through a conductive connecting layer, and the conductive connecting layer is connected with the second ohmic metal electrode;

a first insulating layer disposed on the plurality of light emitting cells and the at least two supporting units, and covering a portion of the second ohmic metal electrode;

at least two metal columns respectively arranged on the plurality of light-emitting units and the at least two supporting units;

wherein the light emitted by the plurality of light emitting units is emitted through the substrate.

2. The laser of claim 1, wherein the second ohmic metal electrode is on the substrate, and a portion of the second ohmic metal electrode is between the plurality of light emitting cells and the at least two support cells.

3. The laser of claim 1, wherein the second ohmic metal electrode surrounds the plurality of light emitting cells.

4. The laser of claim 1, wherein a portion of the conductive connection layer is located on the plurality of light emitting cells and connects to the first ohmic metal electrode to form an anode.

5. The light-emitting device according to claim 1, wherein the conductive connection layer on the supporting unit is connected to the second ohmic metal electrode to form a cathode.

6. The laser of claim 1, wherein a portion of the first insulating layer is located between the at least two support units and the conductive connection layer.

7. The laser of claim 1, wherein a second insulating layer is formed between the plurality of light emitting cells and the at least two supporting cells, the second insulating layer covering a portion of the second ohmic metal electrode.

8. The laser of claim 6, wherein the second insulating layer is further located between the plurality of light emitting cells and between the at least two support cells.

9. The laser of claim 1, wherein the height of each of the metal posts is between 25-35 microns.

10. A method for manufacturing a laser, comprising,

providing a substrate;

forming a plurality of light emitting units on the substrate, wherein a first ohmic metal electrode is arranged on each light emitting unit;

forming at least two supporting units on the substrate, wherein the at least two supporting units are connected through a conductive connecting layer, and the conductive connecting layer is connected with the second ohmic metal electrode;

forming a first insulating layer on the plurality of light emitting units and the at least two supporting units, wherein the first insulating layer covers a part of the second ohmic metal electrode;

forming at least two metal posts on the light emitting units and the at least two supporting units;

wherein the light emitted by the plurality of light emitting units is emitted through the substrate.

Technical Field

The invention relates to the technical field of laser, in particular to a laser and a manufacturing method thereof.

Background

A Vertical-Cavity Surface-Emitting laser (Vertical-Cavity Surface-Emitting L aser, referred to as VCSE L, also known as Vertical Cavity Surface Emitting laser) is a semiconductor laser, the laser is emitted perpendicularly to the top Surface, which is different from the edge Emitting laser generally emitted from the edge, along with the rapid development of technology, the research of VCSE L is deep and the application requirement is expanded, VCSE L not only plays an increasingly important role in the fields of mobile phones, consumer electronics, etc., but also is used for face recognition, 3D sensing, gesture detection and VR (virtual reality)/AR (augmented reality)/MR (mixed reality), etc.

In the existing 3D sensing device, the front emission VCSE L is mostly used, and the front emission VCSE L and the substrate need to be connected by gold wire bonding, which introduces more inductance, thereby affecting the performance of the 3D sensing device.

Disclosure of Invention

In view of the above-mentioned defects of the prior art, the present invention provides a laser, which can be used in a 3D sensing device, and can omit the gold wire bonding step, avoid the inductance effect between gold wires, and improve the performance of the 3D sensing device.

The above and other objects are achieved. The invention provides a laser, comprising,

a substrate;

the light-emitting units are arranged on the substrate, and each light-emitting unit is provided with a first ohmic metal electrode;

the at least two supporting units are arranged on the substrate and connected through a conductive connecting layer, and the conductive connecting layer is connected with the second ohmic metal electrode;

a first insulating layer disposed on the plurality of light emitting cells and the at least two supporting units, and covering a portion of the second ohmic metal electrode;

at least two metal columns respectively arranged on the plurality of light-emitting units and the at least two supporting units;

wherein the light emitted by the plurality of light emitting units is emitted through the substrate.

Further, the second ohmic metal electrode is located on the substrate, and a part of the second ohmic metal electrode is located between the plurality of light emitting units and the at least two supporting units.

Further, the second ohmic metal electrode surrounds the plurality of light emitting cells.

Further, a part of the conductive connection layer is located on the plurality of light emitting units and connected to the first ohmic metal electrode to form an anode.

Further, the conductive connection layer on the supporting unit is connected with the second ohmic electrode to form a cathode.

Further, a portion of the first insulating layer is located between the at least two supporting units and the conductive connection layer.

Further, a second insulating layer is formed between the plurality of light emitting cells and the at least two supporting units, and the second insulating layer covers a portion of the second ohmic metal electrode.

Further, the second insulating layer is also located between the plurality of light emitting units and between the at least two supporting units.

Further, the height of each metal pillar is 25-35 microns.

Furthermore, the invention also provides a manufacturing method of the laser, which comprises the following steps,

providing a substrate;

forming a plurality of light emitting units on the substrate, wherein a first ohmic metal electrode is arranged on each light emitting unit;

forming at least two supporting units on the substrate, wherein the at least two supporting units are connected through a conductive connecting layer, and the conductive connecting layer is connected with the second ohmic metal electrode;

forming a first insulating layer on the plurality of light emitting units and the at least two supporting units, wherein the first insulating layer covers a part of the second ohmic metal electrode;

forming at least two metal posts on the light emitting units and the at least two supporting units;

wherein the light emitted by the plurality of light emitting units is emitted through the substrate.

In summary, the present invention provides a laser and a method for manufacturing the same, in which a plurality of light emitting units and supporting units are formed on a substrate, and then metal pillars are formed on the light emitting units and the supporting units, and the laser is connected to a substrate through the metal pillars, thereby eliminating a gold wire bonding step and avoiding an inductance effect between gold wires. Meanwhile, the metal columns on the back-emitting laser cover the plurality of light-emitting units, so that the heat dissipation effect of the light-emitting units can be improved.

Drawings

FIG. 1: the present embodiment provides a flowchart of a method for manufacturing a laser.

FIG. 2A: the steps S1-S2 are schematic structural diagrams.

FIG. 2B: another schematic structure of steps S1-S2.

FIGS. 3-4: the structure of step S3.

FIG. 5: the structure of step S4.

FIG. 6: fig. 5 is a top view.

FIGS. 7 to 10: the structure of step S5.

FIG. 11: the structure of step S6.

FIG. 12: fig. 11 is a top view.

FIG. 13: array diagram of the laser in this example.

FIG. 14: the present embodiment provides a flowchart of a method for manufacturing a light emitting device.

FIG. 15: the steps S11-S12 are schematic structural diagrams.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

As shown in fig. 1, the present embodiment proposes a method of manufacturing a laser, which may be a back-emitting vertical cavity surface emitting laser, the method including,

s1: providing a substrate;

s2: forming an epitaxial structure on the substrate;

s3: forming a plurality of trenches in the epitaxial structure to divide the epitaxial structure into a plurality of mesa structures;

s4: forming a second ohmic metal electrode in the at least one trench;

s5: forming a first insulating layer and a second insulating layer between the plurality of mesa structures;

s6: and forming a plurality of metal columns on the plurality of mesa structures.

As shown in fig. 2A, in steps S1-S2, a substrate 101 is provided, a first reflective layer 102 is formed on the substrate 101, an active layer 103 is formed on the first reflective layer 102, a second reflective layer 104 is formed on the active layer 103, a P-type contact layer 105 is formed on the second reflective layer 104, and the first reflective layer 102, the active layer 103, the second reflective layer 104 and the P-type contact layer 105 are defined as an epitaxial structure or a stacked structure. In this embodiment, the substrate 101 may be any material suitable for forming a vertical cavity surface emitting laser, such as a substrate of gallium arsenide (GaAs) or other semiconductor material. The substrate 101 may be an N-type doped semiconductor substrate, or a P-type doped semiconductor substrate, and the doping may reduce the contact resistance of the ohmic contact between the subsequently formed ohmic metal electrode and the semiconductor substrate, in this embodiment, the substrate 101 is, for example, an N-type doped semiconductor substrate.

As shown in fig. 2B, in some embodiments, when the substrate 101 is a semi-insulating substrate, the epitaxial structure may further include a buffer layer 102a, the buffer layer 102a is located between the substrate 101 and the first reflective layer 102, the buffer layer 102a has the same doping property as the first reflective layer 102, and the buffer layer 102a may be, for example, an N-type contact layer.

As shown in fig. 2A, in the present embodiment, the first reflective layer 102 may be formed by laminating two materials having different refractive indexes, for example, AlGaAs and GaAs, or AlGaAs of a high aluminum composition and AlGaAs of a low aluminum composition, and the first reflective layer 102 may be an N-type mirror, and specifically, the first reflective layer 102 may be an N-type bragg mirror. The active layer 103 includes a quantum well composite structure formed by stacking GaAs and AlGaAs, or InGaAs and AlGaAs materials, and the active layer 103 converts electric energy into optical energy. The second reflective layer 104 may include a stack of two materials having different refractive indexes, i.e., AlGaAs and GaAs, or AlGaAs of a high aluminum composition and AlGaAs of a low aluminum composition, and the second reflective layer 104 may be a P-type mirror, and particularly, the second reflective layer 104 may be a P-type bragg mirror. The first reflective layer 102 and the second reflective layer 104 are used for reflection enhancement of light generated by the active layer 103 and then emitted from the surface of the first reflective layer 102.

In some embodiments, the first reflective layer 102 or the second reflective layer 104 comprises a series of alternating layers of materials of different refractive indices, wherein the effective optical thickness of each alternating layer (the layer thickness times the layer refractive index) is an odd integer multiple of the operating wavelength of the quarter-wavelength VCSEL, i.e., the effective optical thickness of each alternating layer is a quarter of an odd integer multiple of the operating wavelength of the VCSEL. Suitable dielectric materials for forming the alternating layers of the first reflective layer 102 or the second reflective layer 104 include tantalum oxide, titanium oxide, aluminum oxide, titanium nitride, silicon nitride, and the like. Suitable semiconducting materials for forming the alternating layers of the first reflective layer 102 or the second reflective layer 104 include gallium nitride, aluminum nitride, and aluminum gallium nitride. However, in some embodiments, the first reflective layer 102 and the second reflective layer 104 may be formed of other materials.

In some embodiments, the active layer 103 may include one or more nitride semiconductor layers including one or more quantum well layers or one or more quantum dot layers sandwiched between respective pairs of barrier layers.

As shown in fig. 2A, two first ohmic metal electrodes 109a are further formed on the P-type contact layer 105, a predetermined distance is provided between the two first ohmic metal electrodes 109a, for example, 10-15 μm, and the first ohmic metal electrodes 109a may also serve as metal contact pads of subsequent electrodes. In this embodiment, the first ohmic metal electrode 109a is, for example, a P-type ohmic metal electrode 109 a.

In some embodiments, the first reflective layer 102, the active layer 103, the second reflective layer 104 and the P-type contact layer 105 may be formed, for example, by a chemical vapor deposition method, i.e., an epitaxial structure is formed by a chemical vapor deposition method.

As shown in fig. 3-4, in step S3, a patterned photoresist layer 106 is first formed on the P-type contact layer 105, the patterned photoresist layer 106 covers the first ohmic metal electrode 109a, the patterned photoresist layer 106 exposes a portion of the P-type contact layer 105, and then the exposed epitaxial structure is etched through the patterned photoresist layer 106 to form a plurality of trenches. The arrows in fig. 3 indicate the etching direction.

As shown in fig. 4, in the present embodiment, a plurality of trenches are formed by etching from the P-type contact layer 105 down to the surface of the substrate 101 by an etching process. In the present embodiment, for example, the first trench 1071, the second trench 1072, and the third trench 1073 are formed. By forming the first trench 1071, the second trench 1072 and the third trench 1073, the epitaxial structure is divided into a plurality of mesa structures, such as a first mesa structure 1081, a second mesa structure 1082, a third mesa structure 1083 and a fourth mesa structure 1084. The first mesa structure 1081 and the second mesa structure 1082 are separated by a second trench 1072, the second mesa structure 1082 and the third mesa structure 1083 are separated by a first trench 1071, and the third mesa structure 1083 and the fourth mesa structure 1084 are separated by a third trench 1073. There are also trenches on the left side of the first mesa 1081 and on the right side of the second mesa 1082, which are not labeled in this embodiment.

As shown in fig. 4, in the present embodiment, the first and second mesa structures 1081 and 1082 are identical in structure, the third and fourth mesa structures 1083 and 1084 are identical in structure, and the first and third mesa structures 1081 and 1083 are different in that the first mesa structure 1081 further includes the first ohmic metal electrode 109a, so that the height of the first mesa structure 1081 is greater than the height of the third mesa structure 1083, in the present embodiment, the first and second mesa structures 1081 and 1082 are used to form a light emitting unit, and the third and fourth mesa structures 1083 and 1084 are used to form a supporting unit, which is not used as a light emitting unit, that is, does not emit light.

As shown in fig. 5, after forming a plurality of trenches and a plurality of mesa structures, a second ohmic metal electrode 109b is then formed on the substrate 101 by deposition. The second ohmic metal electrode 109b is located within the first trench 1071, i.e., between the second mesa structure 1082 and the third mesa structure 1083. When a voltage is applied to the first ohmic metal electrode 109a, a current flows from the P-type contact layer 105, the second reflective layer 104, the active layer 103, the first reflective layer 102, and the substrate 101 to the second ohmic metal electrode 109 b. In the present embodiment, the second ohmic metal electrode 109b is, for example, an N-type ohmic metal electrode.

As shown in fig. 6, fig. 6 is a top view of fig. 5, fig. 5 is a cross-sectional view of fig. 6 in the a-a direction, and it should be noted that fig. 6 is only a structure showing the second ohmic metal electrode 109b, fig. 6 is not a limitation of the display size, and the second ohmic metal electrode 109b on the left side of the first mesa structure 1081 is not shown in fig. 5. As can be seen from fig. 6, the second ohmic metal electrode 109b surrounds the first and second mesa structures 1081 and 1082, that is, the second ohmic metal electrode 109b surrounds the light emitting cells, for example, four light emitting cells are formed within the second ohmic metal electrode 109 b. The third and fourth mesa structures 1083 and 1084 are positioned outside the second ohmic metal electrode 109b, that is, the supporting unit is positioned outside the second ohmic metal electrode 109b, that is, the light emitting unit and the supporting unit are spaced apart by the second ohmic metal electrode 109 b.

In some embodiments, for example, two light emitting units may be disposed in the second ohmic metal electrode 109b, and two supporting units may be disposed outside the second ohmic metal electrode 109 b.

As shown in fig. 5 to 6, in the present embodiment, the first mesa structure 1081, the second mesa structure 1082, the third mesa structure 1083 and the fourth mesa structure 1084 are simultaneously formed, and the first mesa structure 1081 and the second mesa structure 1082 are used to form a light emitting unit, the third mesa structure 1083 and the fourth mesa structure 1084 do not function as a light emitting unit, and the third mesa structure 1083 and the fourth mesa structure 1084 function to increase the height of a cathode formed at a later stage, so that the third mesa structure 1083 and the fourth mesa structure 1084 may be formed of an insulating material. For example, the first and second mesa structures 1081 and 1082 are first formed, and then an insulating layer, the height of which may be identical or substantially identical to the heights of the first and second mesa structures 1081 and 1082, is formed outside the second ohmic metal electrode 109 b.

As shown in fig. 7, in step S5, after the second ohmic metal electrode 109b is formed, the sidewalls of the trench are oxidized by high temperature oxidation of highly doped aluminum to form at least one current confinement layer 110 in the second reflective layer 104 of the first mesa structure 1081, the second mesa structure 1082, the third mesa structure 1083 and the fourth mesa structure 1804. The light emitting hole of the light emitting unit is defined by the current confinement layer 110. Note that, since the top view of the first mesa structure 1081 is circular, the current confinement layer 110 is circular in the second reflective layer 105, and when the top view of the first mesa structure 1081 is rectangular, the current confinement layer 110 is annular.

As shown in fig. 7, in the present embodiment, the current confinement layer 110 extends from the sidewall of the second reflective layer 104 toward the inside of the second reflective layer 104, and thus the current confinement layer 110 is defined to be located inside the second reflective layer 104.

In some embodiments, the current confinement layer 110 may also be formed within the first reflective layer 102, and the current confinement layer 110 may also be referred to as a current confinement region.

In some embodiments, a ring-shaped light emitting hole may also be formed within the second reflective layer 104.

As shown in fig. 7, in some embodiments, the current confinement layer 110 includes one of an air pillar type current confinement structure, an ion implantation type current confinement structure, a buried heterojunction type current confinement structure and an oxidation confinement type current confinement structure, and the oxidation confinement type current confinement structure is used in this embodiment.

As shown in fig. 8, after the current confinement layer 110 is formed, the first insulating layer 111 may be formed on the first mesa structure 1081, the second mesa structure 1082, the third mesa structure 1084 and the fourth mesa structure 1084, the first insulating layer 111 may cover the second ohmic metal electrode 109b, and the first insulating layer 111 may cover the plurality of trenches. The first insulating layer 111 is used to insulate the first mesa structure 1081 and the second mesa structure 1082, and also protects the current confinement layer 110. In the present embodiment, the material of the first insulating layer 111 may be silicon nitride or silicon oxide or other insulating materials, the thickness of the first insulating layer 111 may be 100-1000nm, and the first insulating layer 111 may be formed, for example, by chemical vapor deposition.

As shown in fig. 9, after the first insulating layer 111 is formed, a first conductive connection layer 112a is formed on the first and second mesa structures 1081 and 1082, and a second conductive connection layer 112b is formed on the third and fourth mesa structures 1083 and 1084. The first conductive connection layer 112a and the second conductive connection layer 112b may be the same material and may be formed simultaneously. When forming the first conductive connection layer 112a, an opening is formed on the first insulating layer 111 on the first and second mesa structures 1081 and 1082 to expose the first ohmic metal electrode 109a, and then the first conductive connection layer 112a is formed in the opening, and the first conductive connection layer 112a is connected to the first ohmic metal electrode 109 a. When forming the second conductive connection layer 112b, first, an opening is formed on the first insulating layer 111 on the second ohmic metal electrode 109b to expose the second ohmic metal electrode 109b, and then the second conductive connection layer 112b is formed in the opening, the second conductive connection layer 112b is further located on the third mesa structure 1083 and the fourth mesa structure 1084, that is, the third mesa structure 1083 and the fourth mesa structure 1084 are connected through the second conductive connection layer 112b, and the second conductive connection layer 112b is further connected to the second ohmic metal electrode 109 b.

As shown in fig. 4 and 9, the height of the first mesa structure 1081 in fig. 4 is greater than the height of the third mesa structure 1083, and the difference between the heights of the first and third mesa structures 1081 and 1083 is the height of the first ohmic metal electrode 109 a. When the first conductive connection layer 112a and the second conductive connection layer 112b are formed, the first conductive connection layer 112a is in contact with the first ohmic electrode 109a, and the second conductive connection layer 112b on top of the third mesa structure 1083 and the fourth mesa structure 1084 is in contact with the first insulating layer 111, that is, the first insulating layer 111 compensates for the heights of the third mesa structure 1083 and the fourth mesa structure 1084, and thus, the height of the first conductive connection layer 112a may be equal to or substantially equal to the height of the second conductive connection layer 112b on top of the third mesa structure 1083 and the fourth mesa structure 1084, and it can also be described that the heights of the first mesa structure 1081, the second mesa structure 1082, the third mesa structure 1083 and the fourth mesa structure 1084 are equal to or substantially equal to each other, and the first mesa structure 1081 and the second mesa structure 2 include the first reflective layer 102, the active layer 103, the second reflective layer 104, the P-type contact layer 105, the first ohmic metal electrode 109a and the first conductive connection layer 112a, the third mesa structure 1083 and the fourth mesa structure 1084 include the first reflective layer 102, the active layer 103, the second reflective layer 104, the P-type contact layer 105, the first insulating layer 111 and the second conductive connection layer 112 b. In this embodiment, the first ohmic metal electrode 109a and the first conductive connection layer 112a may be defined as an anode, the second ohmic metal electrode 109b and the second conductive connection layer 112b may be defined as a cathode, and when a voltage is applied, a current flows out from the first conductive connection layer 112a, the first ohmic metal electrode 109a, the P-type contact layer 105, the second reflective layer 104, the active layer 103, the first reflective layer 102, the substrate 101, and the second ohmic metal electrode 109b and the second conductive connection layer 112b, so that the current does not pass through the third mesa structure 1083 and the fourth mesa structure 1084, that is, the third mesa structure 1083 and the fourth mesa structure 1084 do not serve as a light emitting unit, and the third mesa structure 1083 and the fourth mesa structure 1084 function to make the heights of the anode and the cathode equal or substantially equal.

As shown in fig. 10, after the first conductive connection layer 112a and the second conductive connection layer 112b are formed, a second insulating layer 113 may be further formed in the plurality of trenches, the second insulating layer 113 being located in the plurality of trenches, that is, between the plurality of mesa structures. For example, when the second insulating layer 113 is positioned between the second mesa structure 1082 and the third mesa structure 1083, the second insulating layer 113 covers the second ohmic metal electrode 109b and a portion of the first insulating layer 111, and the second insulating layer 113 is also positioned between the first mesa structure 1081 and the second mesa structure 1082, and between the third mesa structure 1083 and the fourth mesa structure 1084. The height of the second insulating layer 113 is less than the height of the first mesa structure 1081, e.g., the second insulating layer 113 may be flush with the first insulating layer 111 on the first mesa structure 1081. It should be noted that the second insulating layer 113 cannot cover the first conductive connection layer 112a and the second conductive connection layer 112b on top of the third and fourth mesa structures 1083 and 1084. The second insulating layer 113 may be made of other materials such as BCB organic.

As shown in fig. 10 to 11, in step S6, after the second insulating layer 113 is formed, metal pillars may be further formed on the first and second mesa structures 1081 and 1082 and on the third and fourth mesa structures 1083 and 1084, for example, a first metal pillar 114a and a second metal pillar 114b are shown in fig. 11, and the first metal pillar 114a on the first and second mesa structures 1081 and 1082 is taken as an example in the present embodiment.

As shown in fig. 11, in the present embodiment, the first metal pillar 114a is located on the first mesa structure 1081 and the second mesa structure 1082, the first metal pillar 114a includes a metal layer 1141 and an adhesive layer 1142, the adhesive layer 1142 is also electrically conductive, the adhesive layer 1142 is located on the metal layer 1141, and the metal layer 1141 is located on the first mesa structure 1081 and the second mesa structure 1082 and connected to the first electrically conductive connection layer 112 a. The second metal posts 114b on the third and fourth mesa structures 1083 and 1084 are also connected to the second conductive connection layer 112 b. In this embodiment, the metal layer 1141 may be, for example, copper metal, the adhesive layer 1141 may be, for example, silver-tin alloy, and the heights of the first metal pillar 114a and the second metal pillar 114b may be, for example, 25-35 microns, for example, 30 microns.

As shown in fig. 12, fig. 12 is a plan view of fig. 11, fig. 11 is a cross-sectional view of fig. 12 in the direction B-B, and it should be noted that the figure shows only the relationship between the metal pillar 114 and the mesa structure, and the other structures are not shown in fig. 12. As can be seen from fig. 12, the first metal pillar 114a covers four mesa structures, that is, the first metal pillar 114a covers four light emitting units, and the second metal pillar 114b covers four mesa structures, that is, the second metal pillar 114b covers four supporting units. In the embodiment, since the laser is a back-emitting structure, when the laser is disposed on the substrate, the metal pillar with a larger area covers the light-emitting unit, so as to enlarge the heat dissipation area of the light-emitting unit, and the first metal pillar 114a has good thermal conductivity, so that the heat dissipation of the light-emitting unit can be improved by the first metal pillar 114 a. It should be noted that after the metal pillar is formed, the wafer is further polished, thinned, deposited with the high-reflection film, and cut to form a complete back-emitting vertical cavity surface emitting laser structure, which is not described in this embodiment.

As shown in fig. 11-12, in this embodiment, when the laser needs to be disposed on the substrate, the circuit board connected to the substrate through the first metal pillar 114a and the second metal pillar 114b, that is, the circuit board connected to the substrate through the adhesive layer 1142 on the first metal pillar 114a and the second metal pillar 114b, can be reflowed during heating due to the adhesive layer 1142 being silver-tin alloy, which is also beneficial to the packaging operation in the later stage.

As shown in fig. 13, the present embodiment further provides a laser array 200, where the laser array 200 includes a plurality of lasers 210 and a plurality of supports 220. In the present embodiment, each laser 210 includes, for example, four light emitting cells 211 and a primary anode metal pillar 212. Each support body 220 includes four support units 221 and one cathode metal pillar 222, that is, current flows from the anode metal pillar 212 to the cathode metal pillar 222. In the present embodiment, when the laser array 200 is cut along the X direction, the plurality of lasers 210 may be, for example, separated in the X direction, and when the laser array 200 is cut along the Y direction, the plurality of lasers 210 may be, for example, connected by another metal in the Y direction. In the present embodiment, the lasers 210 in the laser array 200 may be, for example, independent of each other, so that any one of the lasers 210 may be controlled, and the laser 210 is, for example, a back-emitting vertical cavity surface emitting laser.

As shown in fig. 14, the present embodiment further provides a method for manufacturing a light emitting device, including,

s11: providing a substrate;

s12: a laser is disposed on the substrate.

As shown in fig. 15, in steps S11-S12, a substrate 410 is provided, a plurality of metal pads 411 are disposed on the substrate 410, and then the laser 420 is flipped over the substrate 410, i.e. the laser 420 is connected to the metal pads 411 through the anode metal pillar 421 and the cathode metal pillar 422 of the laser 420, for example, the anode metal pillar 421 and the cathode metal pillar 421 are connected to the metal pads 411 by soldering, so that the step of gold wire bonding is omitted, and at the same time, since the bonding layer on the anode metal pillar 421 and the cathode metal pillar 422 is silver-tin alloy, the reflow can be performed during heating, which is also beneficial for the subsequent packaging operation. The specific structure of the laser 420 can be seen, for example, in fig. 12-13. In the present embodiment, the laser 420 is, for example, a back-emitting vertical cavity surface emitting laser, and covers a plurality of light emitting cells under the anode metal pillar 421. When the light emitting device 400 is turned on, light emitted from the laser 420 exits the substrate. Since the plurality of light emitting cells are covered by the anode metal posts 421 having a large area, the heat dissipation areas of the plurality of light emitting cells are increased, and the anode metal posts 421 have good thermal conductivity, thereby improving the heat dissipation of the light emitting device 400.

In this embodiment, the laser may be used as various light sources for light emission, and may be used, for example, for laser radar, infrared camera, 3D depth recognition detector, image signal processing.

The laser in the present embodiment can be used in image forming apparatuses including laser beam printers, copiers, and facsimile machines.

In some embodiments, the laser may also be used as a light source in optical communications, such as a laser source in an optical transceiver module of a fiber optic module.

In summary, the present invention provides a laser and a method for manufacturing the same, in which a laser for back emission is flip-chip mounted on a substrate, that is, the laser is connected to the substrate through a plurality of metal posts, thereby omitting the step of bonding by gold wires, and meanwhile, a plurality of light emitting units are covered by the metal posts, so that the heat dissipation area of the light emitting units is increased, and the heat dissipation effect of the light emitting device is improved.

The above description is only a preferred embodiment of the present application and a description of the applied technical principle, and it should be understood by those skilled in the art that the scope of the present invention related to the present application is not limited to the technical solution of the specific combination of the above technical features, and also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept, for example, the technical solutions formed by mutually replacing the above features with (but not limited to) technical features having similar functions disclosed in the present application.

Other technical features than those described in the specification are known to those skilled in the art, and are not described herein in detail in order to highlight the innovative features of the present invention.