CN111244753A

CN111244753A - Vertical cavity surface emitting laser, manufacturing method thereof and array thereof

Info

Publication number: CN111244753A
Application number: CN202010143263.3A
Authority: CN
Inventors: 刘嵩; 梁栋; 张�成
Original assignee: Vertilite Co Ltd
Current assignee: Vertilite Co Ltd
Priority date: 2020-03-04
Filing date: 2020-03-04
Publication date: 2020-06-05

Abstract

The invention discloses a vertical cavity surface emitting laser, a manufacturing method thereof and an array thereof, wherein the vertical cavity surface emitting laser comprises: the structure of the light emitting device comprises a substrate, a light emitting unit, a first through hole, a second through hole and the like. The invention reduces the packaging complexity, saves the packaging cost, and reduces the parasitic inductance introduced by the gold wire in the packaging, thereby improving the performance of the device under short pulse.

Description

Vertical cavity surface emitting laser, manufacturing method thereof and array thereof

Technical Field

The invention relates to the technical field of semiconductor lasers, in particular to a vertical cavity surface emitting laser, a manufacturing method thereof and an array thereof.

Background

Vertical Cavity Surface Emitting Lasers (VCSELs) are developed based on gallium arsenide semiconductor materials, are different from other light sources such as Light Emitting Diodes (LEDs) and Laser Diodes (LDs), have the advantages of small size, circular output light spots, single longitudinal mode output, small threshold current, low price, easiness in integration into large-area arrays and the like, and are widely applied to the fields of optical communication, optical interconnection, optical storage and the like.

In a conventional front-emitting vertical cavity surface emitting laser array, a common cathode is generally arranged on the back surface of a chip, an anode pad is arranged on the front surface, or both the cathode and the anode pad are arranged on the front surface, and the pad needs to be connected with an external power supply or a driver through a gold wire bonding technology, but in the application of Time of flight (TOF), because a shorter optical pulse is needed, the circuit is affected by the inductance brought by the gold wire, so that the rise Time of light is increased.

Disclosure of Invention

In view of the defects of the prior art, the invention provides the vertical cavity surface emitting laser, the manufacturing method thereof and the array thereof, which can realize the surface mounting of a chip, avoid the use of gold wire bonding technology for electric connection on a front bonding pad, reduce the packaging complexity, save the packaging cost, and reduce the parasitic inductance introduced by gold wires in the packaging, thereby improving the performance of the device under the pulse and reducing the light rising time.

To achieve the above and other objects, the present invention provides a vertical cavity surface emitting laser including:

a substrate;

a light emitting unit formed on the first surface of the substrate, wherein the light emitting unit is provided with a second contact layer;

the first through hole is formed on the substrate and communicated between the first surface and the second surface of the substrate;

the second through hole is formed on the substrate and communicated between the first surface and the second surface of the substrate;

a first electrode contacting the first surface or the second surface of the substrate;

and a second electrode connected to the second contact layer and passing through the second via hole to be connected to a second electrode pad on the second surface of the substrate.

In an embodiment, the first electrode is formed on the second surface of the substrate.

In one embodiment, the first electrode is connected to the first surface of the substrate and passes through the first via to be connected to the first electrode pad on the second surface of the substrate.

In one embodiment, the first electrode and the second electrode are metal conductive layers.

In an embodiment, the substrate is a semi-insulating substrate, the semi-insulating substrate further comprising a first contact layer, wherein the first contact layer is formed on a first surface of the semi-insulating substrate.

In an embodiment, when the substrate is a conductive substrate, the sidewalls of the first through hole, the sidewalls of the second through hole, and the second surface of the substrate are provided with an insulating material.

Another object of the present invention is to provide a method of manufacturing a vertical cavity surface emitting laser, including:

providing a substrate;

forming a light emitting unit on the first surface of the substrate, the light emitting unit being provided with a second contact layer;

forming a first through hole on the substrate, wherein the first through hole is communicated between the first surface and the second surface of the substrate;

forming a second through hole on the substrate, wherein the second through hole is communicated between the first surface and the second surface of the substrate;

forming a first electrode on the first surface or the second surface of the substrate;

and forming a second electrode on the second contact layer, penetrating through the second through hole and connecting with a second electrode pad on the second surface of the substrate.

The present invention also relates to a vertical cavity surface emitting laser array comprising:

a substrate;

the array substrate comprises at least two light emitting units, a first substrate and a second substrate, wherein the light emitting units are arranged on the first surface of the substrate in an array mode, each light emitting unit is provided with a second contact layer, and an insulating unit is arranged between every two adjacent light emitting units;

and a second electrode connected to the second contact layer of each of the light emitting cells and connected to the second electrode pad on the second surface of the substrate through the second via hole.

In one embodiment, the second contact layers of any two of the light emitting units are connected to each other or independent of each other.

The invention provides a vertical cavity surface emitting laser, a manufacturing method thereof and an array thereof.A through hole is arranged on a substrate, and two electrodes of a light-emitting unit are connected to the back surface of the substrate for surface mounting, so that independent control can be realized, the packaging cost and complexity are also saved, the parasitic inductance introduced in packaging is reduced, and the overall performance of driving and devices under pulse is improved. The invention overcomes the defects caused by connecting a current source by using a metal bonding technology, such as the influence of the inductance caused by gold wires on the rise time of light. The invention considers the subsequent packaging mode from the beginning of the design, further changes the traditional mode of connecting the current source by using gold wire bonding, fully utilizes the space on the back surface of the substrate, and ensures that the gold wire bonding technology is not required to be used when the current source is connected, for example, in the application of Time of flight (TOF), the pulse Time is correspondingly shortened, and the distance between the measured target object and the emission source is more accurate. The invention has novel overall concept, and forms the vertical cavity surface emitting laser which can be well connected with a current source directly through surface mounting.

Drawings

FIG. 1: the schematic flow chart of the manufacturing method of the vertical cavity surface emitting laser in one embodiment of the invention;

FIG. 2: an emitter structure of the vertical cavity surface emitting laser in an embodiment of the invention is schematically illustrated;

FIG. 3: a schematic cross-sectional view of a vertical cavity surface emitting laser in an embodiment of the invention;

FIG. 4: a schematic top view of a vertical cavity surface emitting laser in an embodiment of the invention;

FIG. 5: a schematic bottom view of a vertical cavity surface emitting laser in an embodiment of the invention;

FIG. 6 a: in one embodiment of the invention, the cross-sectional view of the vertical cavity surface emitting laser substrate is a conductive substrate;

FIG. 6 b: in an embodiment of the present invention, when the vertical cavity surface emitting laser substrate is a conductive substrate, the first electrode is formed on the second surface of the substrate;

FIG. 7: the schematic flow chart of the manufacturing method of the vertical cavity surface emitting laser array in the embodiment of the invention;

FIG. 8: a schematic cross-sectional view of a vertical cavity surface emitting laser array in an embodiment of the invention;

FIG. 9: a schematic top view of a vertical cavity surface emitting laser array in an embodiment of the invention;

FIG. 10: in an embodiment of the invention, the vertical cavity surface emitting laser array is schematically viewed from the bottom;

FIG. 11: in one embodiment of the present invention, when the substrate is a conductive substrate, an implementation manner of an array is schematically illustrated;

FIG. 12: a bottom view of FIG. 11;

FIG. 13: in an embodiment of the present invention, when the substrate is a semi-insulating substrate, an implementation manner of an array is schematically illustrated;

FIG. 14: fig. 13 is a bottom view.

Description of the symbols

101 substrate

1011 first surface

1012 second surface

102 light emitting unit

1021 first contact layer

1022 second contact layer

1023 first reflecting layer

1024 active layer

1025 second reflecting layer

1026 luminous window

103 first via hole

104 second through hole

105 first electrode

106 second electrode

107 insulating layer

108 insulating unit

B first electrode pad

C second electrode pad

01 first light-emitting unit

02 second light emitting unit

03 third light-emitting unit

04 fourth light emitting unit

05 fifth light emitting unit

06 sixth light emitting unit

07 seventh light emitting unit

08 eighth light emitting unit

09 ninth light emitting unit

10 tenth light emitting unit

P1 first light-emitting unit electrode pad

P3 third light-emitting unit electrode pad

P6 sixth light emitting cell electrode pad

P245 common anode electrode pad

N1 first N type bonding pad

N2 second N type bonding pad

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.

In the present invention, it should be noted that, as the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, their indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the present application and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first" and "second," if any, are used for descriptive and distinguishing purposes only and are not to be construed as indicating or implying relative importance.

The invention provides a vertical cavity surface emitting laser, a manufacturing method thereof and an array thereof.A through hole is arranged on a substrate, two electrodes of a light-emitting unit are connected to the back surface of the substrate for surface mounting.

Referring to fig. 1, an embodiment of the invention provides a method for manufacturing a vertical cavity surface emitting laser, including:

s1, providing a substrate;

s2, forming a light-emitting unit on the first surface of the substrate, wherein the light-emitting unit is provided with a second contact layer;

s3, forming a first through hole on the substrate, wherein the first through hole is communicated between the first surface and the second surface of the substrate;

s4, forming a second through hole on the substrate, wherein the second through hole is communicated between the first surface and the second surface of the substrate;

s5, forming a first electrode on the first surface or the second surface of the substrate;

and S6, forming a second electrode on the first contact layer, penetrating through the second through hole and connecting with a second electrode pad on the second surface of the substrate.

Referring to fig. 3, in detail, in steps S1 to S6, a substrate 101 is first provided, where the substrate 101 is, for example, a semi-insulating substrate or a conductive substrate. The substrate 101 is, for example, any material suitable for forming a vertical cavity surface emitting laser, such as gallium arsenide (GaAs). The substrate 101 is, for example, an N-type doped semiconductor substrate, and is also, for example, a P-type doped semiconductor substrate, and the doping can reduce the contact resistance of ohmic contact between a subsequently formed electrode and the semiconductor substrate. In some embodiments, the substrate 101 is, for example, a sapphire substrate, or at least the top surface of the substrate 101 is comprised of one of silicon, gallium arsenide, silicon carbide, aluminum nitride, gallium nitride.

Referring to fig. 2 to 3, in detail, in step S2, the substrate 101 has a first surface 1011 and a second surface 1012, for example, the first contact layer 1021 is formed on the first surface 1011 of the substrate 101, and the light emitting unit 102 is formed on the first contact layer 1021, where, when the substrate 101 is a conductive substrate (typically, an N-type substrate), the first contact layer 1021 may not be formed, but the invention is not limited thereto. The vcsel of the present invention is, for example, a front-side vcsel, and the light emitting unit 102 includes, in order from bottom to top, a first reflective layer 1023, an active layer 1024, a second reflective layer 1025, a second contact layer 1022, and a light emitting window 1026. The first reflective layer 1023 is formed by laminating two materials having different refractive indexes, including AlGaAs and GaAs, or AlGaAs of a high aluminum composition and AlGaAs of a low aluminum composition, for example, and the first reflective layer 1023 is an N-type bragg mirror, for example. The active layer 1024 includes a quantum well composite structure stacked and composed of GaAs and AlGaAs or InGaAs and AlGaAs materials, and the active layer 1024 is used to convert electrical energy into optical energy. The second reflective layer 1025 is formed of, for example, a stack of two materials having different refractive indices, AlGaAs and GaAs, or AlGaAs of a high aluminum composition and AlGaAs of a low aluminum composition, and the second reflective layer 1025 is, for example, a P-type bragg mirror. The first reflective layer 1023 and the second reflective layer 1025 are used to enhance the reflection of light generated by the active layer 1024 and then emitted from the light emitting window 1026 on the second reflective layer 1025. In some embodiments, the first reflective layer 1023, the active layer 1024, the second reflective layer 1025, and the second contact layer 1022 are formed, for example, by chemical vapor deposition. In some embodiments, the first contact layer between the substrate 101 and the first reflective layer 1023 also has a buffer function to effectively relieve stress and dislocation filtering between the substrate 101 and the first reflective layer 1023.

Referring to fig. 2 to 5, in detail, in steps S3 to S6, the first through hole 103 is formed on the substrate 101 and the first contact layer 1021, the first through hole 103 is connected between the upper surface of the first contact layer 1021 and the second surface 1012 of the substrate 101, and the first through hole 103 is located at one side of the light emitting unit 102, for example. A second via 104 is formed on the substrate 101 and the first contact layer 1021, the second via 104 is connected between the upper surface of the first contact layer 1021 and the second surface 1012 of the substrate 101, and the second via 104 is located on the other side of the light emitting unit 102, for example. In some embodiments, the first through hole 103 and the second through hole 104 may be located on the same side of the light emitting unit 102, or the first through hole 103 and the second through hole 104 may be disposed at any position on the first surface 1011 of the substrate 101 adjacent to the light emitting unit 102 according to design, and the invention is not limited thereto. Referring to fig. 6B, when the substrate 101 is a conductive substrate (generally, an N-type substrate), the first electrode 105 may also be formed directly on the second surface 1012 of the substrate 101 instead of extending to the second surface 1012 of the substrate through the first via 103, in this embodiment, a first contact layer 1021 may also be added between the first electrode 105 and the second surface 1012 of the substrate 101 to ensure the quality of ohmic contact between the first electrode 105 and a semiconductor material, but the invention is not limited thereto. The second electrode 106 is formed on the upper surface of the second contact layer 1022, and the second electrode 106 is connected to the second electrode pad C on the second surface 1012 of the substrate 101 through the second via hole 104. The shape of the first electrode pad B and the second electrode pad C is circular, for example, the size of the first electrode pad B can be enlarged to a required size, and the first electrode pad B is accurately attached to a printed circuit board when surface mounting is carried out. The first electrode 105 and the second electrode 106 are, for example, two different metals or the same metal, such as gold, platinum, nickel or other metal materials.

Referring to fig. 2 to 5, in some embodiments, the first electrode 105 surrounds the light emitting unit 102 on the upper surface of the first contact layer 1021, passes through the first through hole 103, extends to the second surface 1012 of the substrate 101, and is connected to the first electrode pad B on the second surface 1012 of the substrate 101. The second electrode 106 is circularly disposed on the second contact layer 1022 of the light emitting unit 102, and then extends through the second via hole 104 to the second surface 1012 of the substrate 101 to be connected to the second electrode pad C on the second surface 1012 of the substrate 101. The first electrode 105 and the second electrode 106 are, for example, a metal that forms an ohmic contact with a semiconductor substrate, such as gold, and are generally formed by an electroplating or evaporation method. The invention leads the electrode on the first surface 1011 of the substrate 101 to the second surface 1012 of the substrate 101 by providing the through hole on the substrate 101, thereby packaging the electrode by surface mount technology and connecting the electrode with the current source.

Referring to fig. 2 to 5, in some embodiments, for example, an insulating unit 108 is disposed between the first electrode 105 and the second electrode 106, and between the second electrode 106 and the light emitting unit 102, and a material of the insulating unit 108 is, for example, silicon nitride or silicon oxide or other insulating materials. Referring to fig. 3, specifically, in some embodiments, before forming the insulating unit 108 on part or all of the first electrodes 105, the insulating unit 108 contacts part or all of the sidewalls of the light emitting unit 102, the insulating unit 108 may be triangular as shown in fig. 3, and in some embodiments, the insulating unit 108 may also be trapezoidal or linear, which is not limited to the present invention, and then the second electrodes 106 are formed on the upper surfaces of the second contact layers 1022, and the second electrodes 106 are connected to the second electrode pads C on the second surface 1012 of the substrate 101 through the second through holes 104 along the insulating unit 108, so as to isolate the second electrodes 105 from the light emitting unit 102 and the first electrodes 105.

Referring to fig. 2 to 3, when the vcsel operates, a current is injected from the second electrode 106, passes through the second reflective layer 1025, enters the active layer 1024, and forms laser oscillation in the resonant cavity formed by the second reflective layer 1025 and the first reflective layer 1023, thereby emitting light through the light-emitting window 1026. For example, the first electrode 105 is connected to the first contact layer 1021, passes through the first via 103, extends to the second surface 1022 of the substrate 101, is connected to the first electrode pad B on the second surface 1012 of the substrate 101, and the second electrode 106 is connected to the second contact layer 1022, extends to the second surface 1012 of the substrate 101, is connected to the second electrode pad C on the second surface 1012 of the substrate 101, injects a current from the second electrode pad C on the second surface 1012 of the substrate 101, passes through the second reflective layer 1025, enters the active layer 1024, and forms a laser oscillation in a resonant cavity formed by the second reflective layer 1025 and the first reflective layer 1023, and emits light from the light emitting window 1026.

With reference to fig. 2 to fig. 5, the present invention further provides a vertical cavity surface emitting laser, including: a substrate 101, a first contact layer 1021, a light emitting unit 102, a first via 103, a second via 104, a first electrode 105, and a second electrode 106. The light emitting unit 102 the first contact layer 1021 is formed on a first surface 1011 of the substrate 101, the light emitting unit 102 is formed on a first upper surface of the first contact layer 1021, wherein the light emitting unit 102 is provided with a second electrode 106. The first via 103 is formed on the substrate 101 and the first contact layer 1021, and is connected between an upper surface of the first contact layer 1021 and the second surface 1022 of the substrate 101. The second via 104 is formed on the substrate 101 and the first contact layer 1021, and is connected between an upper surface of the first contact layer 1021 and the second surface 1012 of the substrate 101. The first electrode 105 is connected to the first contact layer 1021 and passes through the first via 103 to be connected to the first electrode pad B on the second surface 1012 of the substrate 101. The second electrode 106 is connected to the second contact layer 1022 and passes through the second via 104 to be connected to the second electrode pad C on the second surface 1012 of the substrate 101.

Referring to fig. 2 to 5, the first through hole 103 is disposed on the substrate 101 and located at one side of the light emitting unit 102. The second via 104 is disposed on the substrate 101. The light emitting unit further includes a first reflective layer 1023, an active layer 1024, a second reflective layer 1025, a second contact layer 1022, and a light emitting window 1026. In some embodiments, the first electrode 105 is, for example, wound around the first electrode 1021 at the first contact layer 1021, and extends through the first via 103 to the second surface 1012 of the substrate 101 to connect with the first electrode pad B on the second surface 1012 of the substrate 101. The second electrode 106 is annularly disposed on the second contact layer 1022, and extends through the second through hole 104 to the second surface 1012 of the substrate 101, and is connected to the second electrode pad C on the second surface 1012 of the substrate 101. For example, an insulating unit 108 is formed between the first electrode 105 and the second electrode 106, and between the second electrode 106 and the light emitting unit 102. In some embodiments, the substrate 101 is, for example, a semi-insulating substrate or a conductive substrate.

Referring to fig. 6a to 6b, in some embodiments, when the substrate 101 is a conductive substrate, the sidewalls of the first via 103, the sidewalls of the second via 104, and the second surface 1012 of the conductive substrate are provided with an insulating material, which is denoted as an insulating layer 107. In some embodiments, when the substrate 101 is a conductive substrate (generally, an N-type substrate), the first electrode 105 may also be formed directly on the second surface 1012 of the substrate 101 instead of extending to the second surface 1012 of the substrate through the first via 103, and in some embodiments, the first contact layer 1021 may also be formed on the second surface 1012 of the substrate 101, and the first electrode 105 may also be formed on the first contact layer 1021, so as to ensure the quality of ohmic contact between the first electrode 105 and a semiconductor material, but the invention is not limited thereto.

The present invention also provides a vertical cavity surface emitting laser array formed based on the vertical cavity surface emitting lasers as shown in fig. 2 to 5, and a method of manufacturing the same.

Referring to fig. 7, an embodiment provides a method for fabricating a vertical cavity surface emitting laser array, including:

s201, providing a substrate;

s202, forming at least two light emitting units on the first surface of the substrate, wherein the at least two light emitting units are arranged in an array on the first surface of the substrate, each light emitting unit is provided with a second contact layer, and an insulating unit is arranged between every two adjacent light emitting units;

s203, forming a first through hole on the substrate, wherein the first through hole is communicated between the first surface and the second surface of the substrate;

s204, forming a second through hole on the substrate, wherein the second through hole is communicated between the first surface and the second surface of the substrate;

s205, forming a first electrode on the first surface or the second surface of the substrate;

and S206, forming a second electrode on the second contact layer, penetrating through the second through hole and connecting with a second electrode pad on the second surface of the substrate.

Referring to fig. 8 to 10, in detail, in step S201, the substrate 101 is, for example, any material suitable for forming a vertical cavity surface emitting laser, such as gallium arsenide (GaAs) or other semiconductor materials. The substrate 101 is, for example, an N-type doped semiconductor substrate, and is also, for example, a P-type doped semiconductor substrate, and the doping can reduce the contact resistance of ohmic contact between a subsequently formed electrode and the semiconductor substrate. Referring to fig. 3, in some embodiments, when the substrate 101 is a semi-insulating substrate, a contact layer is disposed on a front surface of the substrate. Referring to fig. 6a and 6b, in some embodiments, when the substrate 101 is a conductive substrate, the sidewalls of the first through hole 103, the sidewalls of the second through hole 104, and the back surface of the conductive substrate 101 are provided with an insulating material.

Referring to fig. 8 to 10, in step S202, at least two light emitting units 102 are arranged in an array on the first surface 1011 of the substrate 101, and each light emitting unit 102 has a second contact layer 1022. In the present embodiment, the light emitting units 102 are arranged regularly, for example, in an array, the array may be an M × N array (M and N represent arbitrary numbers), for example, M and N are different/the same numbers, and in some embodiments, the light emitting units 102 may also be randomly distributed. A plurality of the light emitting units 102 may be spaced closely for better pattern resolution (e.g., 10-30 microns apart). For example, an insulating unit 108 is formed between every two adjacent light emitting units 102, the material of the insulating unit 108 is, for example, silicon nitride or silicon oxide or other insulating materials, the insulating unit 108 is, for example, a rectangle as shown in fig. 8, the insulating unit 108 is, for example, a line, and the invention is not limited thereto, and the insulating unit 108 is, for example, made of silicon nitride or silicon oxide or other insulating materials, and the insulating unit 108 achieves electrical insulation between the first electrode 105 and the second electrode 106 and facilitates electrical connection between part or all of the second electrodes 106. In the present invention, when the kinds of substrates are different, the requirements for the vertical cavity surface emitting laser of the present invention are also different, for example, when the first electrode 105 or the second electrode 106 of each adjacent two of the light emitting cells 102 are connected to each other, a common anode or a common cathode is implemented between each light emitting cell 102. When the first electrodes 105 or the second electrodes 106 of every two adjacent light emitting units 102 are independent from each other, independent control is realized between each light emitting unit 102.

Referring to fig. 8 to 10, in particular, in steps S203 to S204, the first through hole 103 and the second through hole 104 are the same through holes as those in steps S3 to S4, but the positions of the through holes are changed as the number of the arrays is increased, because at least two light emitting units 102 are located between the first through hole 103 and the second through hole 104. The sizes of the first through hole 103 and the second through hole 104 are not limited, and metal can pass through the first through hole and the second through hole. In steps S205 to S206, the connection manner is similar to that in steps S5 to S6, and is not described herein again.

The invention also provides a vertical cavity surface emitting laser array manufactured by the array method.

Referring to fig. 8 to 10, an embodiment provides a vertical cavity surface emitting laser array, which includes a substrate 101, at least two light emitting units 102, a first via 103, a second via 104, a first electrode 105, and a second electrode 106. Here, the positions of the first through holes 103 and the second through holes 104 are changed as the number of arrays increases. At least two of the light emitting cells 102 disposed on the first surface of the substrate 101, each of the light emitting cells 102 having a second contact layer 1022. The first through hole 103 is formed on the substrate 101 at one side of at least two of the light emitting cells 102. The second through hole 104 is formed on the substrate 101 at the other side of at least two of the light emitting cells 102, wherein the first electrode 105 is connected to the first surface 1011 of the substrate 101 and passes through the first through hole 103 to be connected to the first electrode pad B on the second surface 1012 of the substrate 101. The second electrode 106 is connected to the second contact layer 1022 of each of the light emitting cells 102 and passes through the second via hole 104 to be connected to the second electrode pad C on the second surface 1012 of the substrate 101. When the first electrodes 105 or the second electrodes 106 of every two adjacent light emitting units 102 are connected to each other, a common anode or a common cathode is realized between each light emitting unit 102. When the first electrodes 105 or the second electrodes 106 of every two adjacent light emitting units 102 are independent from each other, independent control is realized between each light emitting unit 102.

Referring to fig. 6a, 11 to 12, in some embodiments, when the substrate 101 is a conductive substrate, an insulating material is disposed on the sidewalls of the through holes and the second surface 1012 of the substrate 101 to form an insulating layer 107, such as PBO or SiN. The first electrode 105 and the second electrode 106 extend through the first via 103 and the second via 104 onto the second surface 1012 of the substrate 101. Since the substrate 101 is conductive, an array is formed, for example, by connecting the second contact layers 1022 (e.g., P-type contact layers) of the light emitting cells on the first surface 1011 of the substrate 101 to each other to provide a connection mode. Also for example, the second contact layer 1022 (e.g., P-type contact layer) extends to the second surface 1012 of the substrate 101 through the second via 104 to form a P-type pad (for soldering) to set a connection manner, so as to form a group of independently controlled arrays, wherein the arrangement manner between the light emitting units can be matched in any combination.

As shown in fig. 11 to 13, in an embodiment, the second light emitting unit 02, the fourth light emitting unit 04, and the fifth light emitting unit 05 are connected to each other through the P-type contact layer of each light emitting unit on the first surface 1011 of the substrate 101 to form a group of arrays, and the P-type contact layer is connected to the second surface 1012 through the second through hole 104 by an electrode material to form a common anode electrode pad P245, wherein an insulating unit 108 is disposed between the second light emitting unit 02, the fourth light emitting unit 04, and the fifth light emitting unit 05 to prevent the first electrode 105 from contacting the second electrode 106 to cause a short circuit. The first light emitting unit 01, the third light emitting unit 03, and the sixth light emitting unit 06 are formed as a group of arrays by connecting P-type contact layers to the second surface 1012 through the second via hole 104 by electrode materials, respectively, to form independent P-type pads, wherein the independent P-type pads are referred to as a first light emitting unit electrode pad P1, a third light emitting unit electrode pad P3, and a sixth light emitting unit electrode pad P6, and the first light emitting unit electrode pad P1 and the third light emitting unit electrode pad P3 are connected again on the second surface 1012 to form a group of arrays. An insulating unit 108 is disposed between the first light emitting unit 01, the third light emitting unit 03 and the sixth light emitting unit 06 and the respective adjacent through holes to prevent the first electrode 105 and the second electrode 106 from contacting each other to cause a short circuit.

Referring to fig. 6b, in an embodiment, when the substrate 101 is a conductive substrate, the first electrode 105 can also be directly formed on the second surface 1012 of the substrate 101, and directly connected to a printed circuit board, so that the first electrode 105 does not need to extend to the second surface 1012 of the substrate 101 through the first through hole 103. Specifically, for example, the first contact layer 1021 is formed on the second surface 1012 of the substrate 101, and the first electrode 105 is formed on the first contact layer 1021.

Referring to fig. 6, 13-14, when the substrate is a semi-insulating substrate, there are two ways to implement the independent control array. In one embodiment, the connection is provided by the connection between the P-type contact layers or the N-type contact layers of the light emitting units on the first surface 1011. In another embodiment, the connections are provided by forming a P-type pad or an N-type pad on the second surface 1012, forming a set of independently controlled arrays. In addition, the two setting modes can be combined and matched at will. As shown in fig. 13 to 14, in an embodiment, the seventh light emitting unit 07 and the eighth light emitting unit 08 are connected through an N-type contact layer on the first surface 1011. The ninth light emitting unit 09 and the tenth light emitting unit 10 are connected through the P-type contact layer on the first surface 1011. The seventh light emitting unit 07 forms a first N-type pad N1 on the second surface 1012, the ninth light emitting unit 09 forms a second N-type pad N2 on the second surface 1012, and the first N-type pad N1 and the second N-type pad N2 are connected to each other on the second surface 1012. In this embodiment, the seventh light emitting unit 07, the eighth light emitting unit 08, the ninth light emitting unit 09, and the tenth light emitting unit 10 can be connected in any combination, that is, in multiple ways, such as common anode connection, common cathode connection, or independent connection, and each connected light emitting unit can be controlled to be turned on or turned off independently. An insulating unit 108 is disposed between the seventh light emitting unit 07, the eighth light emitting unit 08, the ninth light emitting unit 09, and the tenth light emitting unit 10 and respective adjacent through holes to prevent a short circuit caused by contact between the first electrode 105 and the second electrode 106, and an insulating unit 108 is also disposed between the ninth light emitting unit 09 and the tenth light emitting unit 0110.

In summary, the present invention provides a vertical cavity surface emitting laser, a method for manufacturing the same, and an array thereof, in which through holes are formed in a substrate, and two electrodes of a light emitting unit are connected from a first surface of the substrate to a second surface of the substrate for surface mounting, so that defects caused by using a metal bonding technology to connect to a current source, such as the influence of inductance caused by gold wires on the light rise time, are overcome. The invention considers the subsequent packaging mode from the beginning of the design, further changes the traditional mode of connecting the current source by using gold wire bonding, fully utilizes the space on the back surface of the substrate, ensures that the gold wire bonding technology is not needed when the current source is connected, correspondingly shortens the pulse Time in the application of Time of flight (TOF), and ensures that the distance between the measured target object and the emission source is more accurate. The invention has novel overall concept, and forms the vertical cavity surface emitting laser which can be well connected with a current source directly through surface mounting.

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.

Claims

1. A vertical cavity surface emitting laser, comprising:

a substrate;

2. A vertical cavity surface emitting laser according to claim 1, wherein said first electrode is formed on a second surface of said substrate.

3. A vertical cavity surface emitting laser according to claim 1, wherein said first electrode is connected to a first surface of said substrate and passes through said first via hole to be connected to a first electrode pad on a second surface of said substrate.

4. A vertical cavity surface emitting laser according to claim 1, wherein said first electrode and said second electrode are metal conductive layers.

5. A vertical cavity surface emitting laser according to claim 1, wherein said substrate is a semi-insulating substrate further comprising a first contact layer, wherein said first contact layer is formed on a first surface of said semi-insulating substrate.

6. A vertical cavity surface emitting laser according to claim 1, wherein when said substrate is a conductive substrate, insulating materials are provided on a side wall of said first via hole, a side wall of said second via hole, and a second surface of said substrate.

7. A method of manufacturing a vertical cavity surface emitting laser, comprising:

providing a substrate;

8. A vertical cavity surface emitting laser array, comprising:

a substrate;

9. The VCSEL array of claim 8, wherein the substrate is a semi-insulating substrate further comprising a first contact layer, wherein the first contact layer is formed on a first surface of the semi-insulating substrate.

10. The VCSEL array of claim 8, wherein the second contact layers of any two of the light emitting cells are connected to each other or independent from each other.