CN111900623B

CN111900623B - Laser device and manufacturing method and application thereof

Info

Publication number: CN111900623B
Application number: CN202010761459.9A
Authority: CN
Inventors: 梁栋; 张�成; 刘嵩
Original assignee: Vertilite Co Ltd
Current assignee: Vertilite Co Ltd
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2021-11-30
Anticipated expiration: 2040-07-31
Also published as: CN111900623A

Abstract

The invention provides a laser and a manufacturing method and application thereof, comprising the following steps: providing a laser chip, wherein the laser chip comprises at least two platform-shaped structures, a cutting channel is arranged between every two adjacent platform-shaped structures, and a light-emitting hole is formed in each platform-shaped structure; forming an optical element on the laser chip, wherein the laser beam emitted by the light emitting hole is emitted through the optical element; and cutting through the cutting channels to form a plurality of lasers, wherein each laser comprises at least one table-shaped structure. The manufacturing method of the laser can reduce the thickness of the laser.

Description

Laser device and manufacturing method and application thereof

Technical Field

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

Background

A Vertical Cavity Surface Emitting Laser (VCSEL) is developed based on a gallium arsenide semiconductor material, is different from other light sources such as an LED (light Emitting Diode) and an LD (Laser Diode), has the advantages of small volume, circular output light spot, single longitudinal mode output, small threshold current, low price, easy integration into a large-area array, and the like, and is widely applied to the fields of optical communication, optical interconnection, optical storage, and the like.

In the application of three-dimensional Sensing (3D Sensing), the vcsel usually needs to work in combination with other optical elements, and the optical elements are usually fixed on the optical elements through a bracket, so the optical module is thick and cannot be applied to miniaturized and ultra-thin electronic devices.

In other prior art techniques, the optical element may be deposited on the laser chip and then the optical element may be imprinted with an optical pattern, but damage may be caused to the laser chip during the imprinting process.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a laser and a manufacturing method and application thereof, which improve the manufacturing method of the laser by integrating an optical element on a laser chip, reduce the thickness of the laser, and avoid damage to the laser chip.

To achieve the above and other objects, the present invention provides a method of manufacturing a laser, including:

providing a laser chip, wherein the laser chip comprises at least two platform-shaped structures, a cutting channel is arranged between every two adjacent platform-shaped structures, and a light-emitting hole is formed in each platform-shaped structure;

forming an optical element on the laser chip, wherein the laser beam emitted by the light emitting hole is emitted through the optical element;

cutting through the cutting streets to form a plurality of the lasers, the lasers including at least one of the mesa structures;

wherein the optical element is disposed on the laser chip through an adhesive layer having a thickness greater than a thickness of the optical element;

wherein the optical element comprises:

a first material layer;

a second material layer on the first material layer;

a transparent top liner positioned on the second material layer;

the first material layer and the second material layer have different refractive indexes, and have mutually matched optical patterns which are irregular in undulation.

Further, the mesa structure is located on the substrate, the mesa structure including:

a first reflective layer having a first surface and a second surface;

an active layer on the first surface;

a second reflective layer on the active layer.

Further, when the laser is in a front-side configuration, the optical element is located on the first surface of the first reflective layer; when the laser is in a back-side configuration, the optical element is located on the second surface of the first reflective layer.

Further, when the laser is a front structure, at least one through hole is formed on the first reflective layer before the optical element is formed, the through hole communicating the first surface and the second surface; and the first electrode on the mesa structure is positioned in the through hole.

Further, after forming the optical element, the method further includes peeling off the substrate and depositing a first electrode on a second surface of the first reflective layer, the first electrode on the second surface being connected to the first electrode in the through hole.

Further, when the laser is in a front structure, the laser further includes a second electrode located on the first surface or the second surface of the first reflective layer.

Further, when the laser is of a backside structure, the substrate is also thinned before the optical element is formed.

Further, when the laser is a back structure, the laser further includes a first electrode and a second electrode, the first electrode is located on the mesa structure, and the second electrode is located on the first reflective layer or the support structure.

Further, the present invention also provides a laser, including:

at least one table structure, wherein the table structure is internally provided with a light emitting hole;

an optical element disposed on the laser chip, through which the laser beam emitted from the light emitting hole exits;

wherein the optical element comprises:

a first material layer;

a second material layer on the first material layer;

a transparent top liner positioned on the second material layer;

Further, the present invention also provides an electronic device, comprising:

the light emitting module is used for emitting laser beams, and the laser beams are reflected by the target object to form reflected beams;

the light receiving module is used for receiving the reflected light beam;

wherein, the optical transmission module includes at least one laser instrument, the laser instrument includes:

wherein the optical element comprises:

a first material layer;

a second material layer on the first material layer;

a transparent top liner positioned on the second material layer;

In summary, the present invention provides a laser and a method for manufacturing the same, in which an adhesive layer is disposed on a laser chip, and then an optical element is disposed on the adhesive layer, and a laser beam emitted from the laser chip is emitted through the optical element, thereby integrating the optical element on the laser chip. In the manufacturing method, the optical element is not arranged on the laser chip through other structures, so that the process can be simplified, and the thickness of the laser can be reduced.

Meanwhile, as the distance between the light emitting hole in the laser chip and the optical element is increased, light spots on the optical element become larger, the number of microstructures covering the optical element by the light spots becomes larger, and therefore the uniformity of a far field of an emitting end is better.

Meanwhile, because the optical element is already formed with the optical pattern before being fixed on the adhesive layer, when the optical element is fixed on the adhesive layer, the optical element is not required to be subjected to nano-imprinting, so that damage to the laser chip can be avoided.

Drawings

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

FIG. 2: the steps S1-S2 correspond to the schematic structural diagram.

FIG. 3: step S3 is shown in the corresponding schematic diagram.

FIG. 4: the structure of the table structure is schematically shown.

FIG. 5: the structure of the through hole is shown schematically.

FIG. 6: the structure of the first electrode is schematically shown.

FIG. 7: schematic structural representations of the adhesive layer and the optical element.

FIG. 8: the structure of the laser is schematically shown.

FIG. 9: another structure schematic diagram of the laser.

FIG. 10: another schematic of an optical pattern.

FIG. 11: schematic diagram of the cutting path.

FIG. 12: fig. 10 is a side view.

FIG. 13: the structure of the laser is schematically shown.

FIG. 14: another structure schematic diagram of the laser.

FIG. 15: another structure schematic diagram of the laser.

FIG. 16: another structure schematic diagram of the laser.

FIG. 17: another structure schematic diagram of the laser.

FIG. 18: another structure schematic diagram of the laser.

FIG. 19: the laser array forms a brief schematic of the spot.

FIG. 20: another schematic of the laser array forming the spot.

FIG. 21: a schematic diagram of the electronic device in this embodiment.

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 provides a method for manufacturing a laser, including:

s1: providing a laser chip, wherein the laser chip comprises at least two platform-shaped structures, a cutting channel is arranged between every two adjacent platform-shaped structures, and a light-emitting hole is formed in each platform-shaped structure;

s2: forming an optical element on the laser chip, wherein the laser beam emitted by the light emitting hole is emitted through the optical element;

s3: and cutting through the cutting channels to form a plurality of lasers, wherein each laser comprises at least one table-shaped structure.

As shown in fig. 2, in steps S1-S2, a laser chip 10 is first provided, and the laser chip 10 may include at least two mesa structures, each mesa structure having a light emitting hole therein for emitting a laser beam. An optical element 30 is formed on the upper surface of the laser chip 10, and the optical element 30 may be disposed on the upper surface of the laser chip 10 through an adhesive layer 20. A first electrode 10a and a second electrode 10b are provided on the lower surface of the laser chip 10, and the first electrode 10a and the second electrode 10b are provided at an interval.

As shown in fig. 3, in step S3, a plurality of scribe lines (not shown) are provided on the laser chip 10, the scribe lines being located between the first electrode 10a and the second electrode 10 b. The dicing is performed by a laser, thereby forming a plurality of lasers 100.

As shown in fig. 2 to 3, in the present embodiment, the laser chip 10 and the optical element 30 are first separately manufactured, and then the optical element 30 is fixed on the laser chip 10 by the adhesive layer 20, and then the laser 100 is formed by dicing. Since the optical element 30 is integrated on the laser chip 10, the thickness of the laser 100 can be reduced.

As shown in fig. 2 and 4, in forming the laser chip 10, a semiconductor substrate 101 is first provided, and then a first reflective layer 102, an active layer 103, and a second reflective layer 104 are sequentially formed on the semiconductor substrate 101.

As shown in fig. 4, the semiconductor substrate 101 may be any material suitable for forming a vertical cavity surface emitting laser, such as gallium arsenide (GaAs). The semiconductor 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 electrode and the semiconductor substrate, in this embodiment, the semiconductor substrate 101 is an N-type doped semiconductor substrate.

In some embodiments, the semiconductor substrate 101 may be a sapphire substrate or other material substrate, or at least the top surface of the semiconductor substrate 101 is composed of one of silicon, gallium arsenide, silicon carbide, aluminum nitride, gallium nitride.

As shown in fig. 3 to 4, in the present embodiment, the first reflective layer 102 is located on the semiconductor substrate 101, the first reflective layer 102 may be formed by laminating two materials having different refractive indexes, including AlGaAs and GaAs, or AlGaAs of high aluminum composition and AlGaAs of low aluminum composition, for example, the first reflective layer 102 may be an N-type mirror, and the first reflective layer 102 may be an N-type bragg mirror.

As shown in fig. 4, in the present embodiment, an active layer 103 is positioned on the first reflective layer 102, and the active layer 103 includes a first semiconductor layer 1031, an active region 1032, and a second semiconductor layer 1033. The active region 1032 is located between the first semiconductor layer 1031 and the second semiconductor layer 1033. In fig. 4, the first semiconductor layer 1031 and the second semiconductor layer 1033 include one single material layer, but both the first semiconductor layer 1031 and the second semiconductor layer 1033 may include more than two layers. The first semiconductor layer 1031 and the second semiconductor layer 1033 may include InGaAs, GaAs, and AlGaAs, wherein the first semiconductor layer 1031 may be doped N-type and the second semiconductor layer 1033 may be doped P-type. In some embodiments, the first semiconductor layer 1031 and the second semiconductor layer 1033 may also comprise other materials that are specifically configured with different doping. In this embodiment, the active region 1032 may also be referred to as an active region, and the active region 1032 includes a plurality of quantum structure layers therein, the quantum structure layers having a bandgap wavelength, each of the quantum structure layers emitting light at an operating wavelength.

As shown in fig. 4, in the present embodiment, the second reflective layer 104 may include a stack of two materials having different refractive indexes, i.e., AlGaAs and GaAs, or AlGaAs with a high aluminum composition and AlGaAs with a low aluminum composition, the second reflective layer 104 may be a P-type mirror, and 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 or the second reflective layer 104.

As shown in FIG. 4, 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 VCSEL, i.e., the effective optical thickness of each alternating layer is an odd integer multiple of a quarter 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.

As shown in fig. 4, in the present embodiment, the first reflective layer 102, the active layer 103, and the second reflective layer 104 may be defined as mesa structures 108, trenches 107 may be formed between the mesa structures 108, and scribe lines may be formed in the trenches 107. The laser is cut through the cutting path, and the laser can be divided into two subunits. Of course, in some embodiments, the active layer 103 and the second reflective layer 104 may also be defined as a mesa structure 108.

As shown in fig. 4, in the present embodiment, a conductive contact layer 105 is further disposed on the mesa structure 108, that is, the conductive contact layer 105 is located on the second reflective layer 104, the conductive contact layer 105 can be used as a reference for photolithography calibration in a subsequent process, so as to prepare a vertical cavity surface emitting laser with higher precision, and the conductive contact layer 105 can also be used as a metal contact pad of a subsequent first electrode. The material of the conductive contact layer 105 may include one or a combination of Au metal, Ag metal, Pt metal, Ge metal, Ti metal, and Ni metal, and may be selected according to the requirement. In this embodiment, the shape of the conductive contact layer 105 may be, for example, a circular ring shape, and in some embodiments, the shape of the conductive contact layer 105 may also be an elliptical ring shape, a rectangular ring shape, or a hexagonal ring shape, and the shape of the conductive contact layer 105 may be selected as needed. The conductive contact layer 105 may be formed, for example, by a chemical vapor deposition method.

As shown in fig. 4, after the mesa structure 108 is formed, a current confinement layer 106 is then formed in the second semiconductor layer 1033, one end of the current confinement layer 106 is connected to a sidewall of the second semiconductor layer 1033, and the other end of the current confinement layer 106 extends within the second semiconductor layer 1033 to form a light emitting hole in the second semiconductor layer 1033. The current confinement layer 106 may be formed, for example, by high temperature oxidation of highly doped aluminum. In this embodiment, since the reflectivity of the first reflective layer 102 is greater than the reflectivity of the second reflective layer 104, the laser 100 has a front structure, i.e., the laser beam emitted from the light emitting hole exits through the second reflective layer 104.

As shown in fig. 4, in some embodiments, the current confinement layer 106 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. 5, after forming the mesa structure 108, at least one via 109 is first formed in the trench 107, one via 109 being shown in fig. 5. The through hole 109 penetrates the first reflective layer 102, that is, the through hole 109 exposes the semiconductor substrate 101. In this embodiment, an upper surface of the first reflective layer 102 may be defined as a first surface, and a lower surface of the first reflective layer 102 may be defined as a second surface. The active layer 103 may be on a first surface of the first reflective layer 102.

As shown in fig. 6, after the via 109 is formed, an insulating layer 110 is first formed on the mesa structure 108, the insulating layer 110 substantially covering the mesa structure 108. In this embodiment, the insulating layer 110 extends from the top of the mesa structure 108 onto the first surface of the first reflective layer 102. The insulating layer 110 is further located in the through hole 109, it should be noted that the insulating layer 110 is located on a sidewall of the through hole 109, and the insulating layer 110 does not completely fill the through hole 109. It should be noted that after the insulating layer 110 is formed, a portion of the insulating layer 110 on the conductive contact layer 105 needs to be removed, so that the conductive contact layer 105 can be connected to a first electrode formed later. The insulating layer 110 may be silicon nitride or silicon oxide or other insulating materials, the thickness of the insulating layer 110 may be 100-300nm, the insulating layer 110 may protect the current confinement layer 106, and in this embodiment, the insulating layer 110 may be formed, for example, by chemical vapor deposition.

As shown in fig. 6, after the insulating layer 110 is formed, the first electrode 10a is then formed on the insulating layer 110, the first electrode 10a is in contact with the conductive contact layer 105, and the first electrode 10a extends from the conductive contact layer 105 along the sidewall of the mesa structure 108 and then extends into the via hole 109. As can be seen from fig. 6, the first electrodes 10a of the two mesa-shaped structures 108 are connected, i.e. the two mesa-shaped structures 108 share the first electrode 10a, so that the two mesa-shaped structures 108 can be lit up simultaneously. Of course, in some embodiments, the first electrodes 10a of the two mesa-shaped structures 108 may be separated, for example, an insulating layer 110 is formed again in the through holes 109, and the insulating layer 110 is located between the first electrodes 10a, thereby separating the first electrodes 10a of the two mesa-shaped structures 108, and thus realizing the independent control of the two mesa-shaped structures 108. Of course, in some embodiments, when two through holes 109 are formed between the mesa structures 108, the first electrodes 10a of the two mesa structures 108 may be separated, thereby achieving independent control of the two mesa structures 108. The first electrode 10a is, for example, a P-type electrode, the first electrode 10a is, for example, an anode, and the material of the first electrode 10a may include one or a combination of Au metal, Ag metal, Pt metal, Ge metal, Ti metal, and Ni metal.

As shown in fig. 7, after the first electrode 10a is formed, an adhesive layer 20 is fixed on the mesa structure 108, the adhesive layer 20 being located on the first surface of the first reflective layer 102, the adhesive layer 20 having a height greater than that of the mesa structure 108, i.e., the adhesive layer 20 covering the mesa structure 108. In the present embodiment, the adhesive layer 20 extends from the first reflective layer 102, specifically, the bottom of the adhesive layer 20 contacts the first electrode 10a first, then fills the trench 107, and then the top of the adhesive layer 20 is a planar structure on the top of the mesa structure 108. In the present embodiment, the thickness of the bonding layer 20 may be 20 to 1000 micrometers, for example, 500 micrometers. On top of the adhesive layer 20 there is an optical element 30, the thickness of the adhesive layer 20 being larger than the thickness of the optical element 30. The optical element 30 comprises a first layer of material 31, a second layer of material 32 and a transparent top liner 33. A first material layer 31 is positioned on the adhesive layer 20, a second material layer 32 is positioned on the first material layer 31, and a transparent top liner 33 is positioned on the second material layer 32. The refractive index of the first material layer 31 is lower than that of the second material layer 32, the refractive index of the first material layer 31 may be between 1.0 and 2.0, and the refractive index of the second material layer 32 may be between 1.5 and 4.0. The first material layer 31 may be a low refractive index material such as silicon dioxide or silicon nitride or a polymer. Second material layer 32 may be a low index of refraction material such as silicon dioxide or silicon nitride or a polymer. The thickness of the first material layer 31 may be between 20-1000 microns, for example 30 microns; second material layer 32 may have a thickness of between 20-1000 microns, such as 30 microns. The contact surfaces of the first material layer 31 and the second material layer 32 have mutually matched optical patterns 34, the optical patterns 34 may have irregular undulations, and the optical patterns 34 may be formed by a nano-imprinting or etching process. In an embodiment, the transparent top substrate 33 may be a sapphire substrate, a silicon dioxide substrate, a glass substrate, or the like. The optical element 30 may be any one or combination of a diffuser, refractive optical element, diffractive optical element, grating structure, superstructure or super-surface. Note that the refractive index of the adhesive layer 20 is not limited in this embodiment.

As shown in fig. 8, after the optical element 30 is fixed on the adhesive layer 30, the semiconductor substrate 101 is first peeled off to expose the second surface of the first reflective layer 102. Then, depositing an insulating layer 110 on the second surface of the first reflective layer 102, wherein the insulating layer 110 on the second surface is connected to the insulating layer 110 in the through hole 109; then, the region corresponding to the active layer 103 on the second surface and the region corresponding to the through hole 109 are removed; then, a deposition step is performed to form a first electrode 10a and a second electrode 10b on the second surface of the first reflective layer 102, wherein the first electrode 10a on the second surface of the first reflective layer 102 is connected to the first electrode 10a in the through hole 109, and an insulating layer 110 is disposed between the first electrode 10a on the second surface of the first reflective layer 102 and the first reflective layer 102. The second electrode 10b is in direct contact with the first reflective layer 102. The second electrode 10b is, for example, an N-type electrode, and the second electrode 10b is, for example, a cathode. The material of the second electrode 10b may include one or a combination of Au metal, Ag metal, Pt metal, Ge metal, Ti metal, and Ni metal.

As shown in fig. 8, in the present embodiment, the laser has a front structure, that is, the optical element 30 is located on the light emitting region, and the laser beam is emitted through the optical element 30. Since the distance between the light emitting hole and the optical element 30 is increased, the light spot impinging on the optical element becomes larger, the number of microstructures covering the optical element of the light spot becomes larger, and therefore the uniformity of the far field of the emission end is better.

As shown in fig. 9, the present embodiment further provides a laser, which has a back structure. The back structure laser is fabricated in a similar manner to the front structure laser. The laser manufacturing method comprises the steps of firstly providing a semiconductor substrate 101, and then forming a mesa structure 108 on the lower surface of the semiconductor substrate 101, so as to form a laser chip. The laser chip is a back surface structure, an adhesive layer 20 is provided on the upper surface of the semiconductor substrate 101, an optical element 30 is fixed on the adhesive layer 20, and a laser beam emitted from the laser chip is emitted from the optical element 30.

As shown in fig. 9, in the present embodiment, the laser includes a semiconductor substrate 101, and a first reflective layer 102 is formed on a lower surface of the semiconductor substrate 101, where a surface of the first reflective layer 102 contacting the semiconductor substrate 101 is defined as a second surface, and a surface of the first reflective layer 102 away from the semiconductor substrate 101 is defined as a first surface. Two mesa-shaped structures 108 are arranged on the first surface of the first reflective layer 102, and a support structure 111 is further arranged between the two mesa-shaped structures 108. The mesa structure 108 includes an active layer 103 and a second reflective layer 104, and the active layer 103 includes a first semiconductor layer 1031, an active region 1032 and a second semiconductor layer 1032. A current confinement layer 106 is provided in the second semiconductor layer 1032, and a light emitting hole is defined by the current confinement layer 106. The mesa structure 108 is further provided with a first electrode 10a, and an insulating layer 110 is further provided between the first electrode 10a and the mesa structure 108. A second electrode 10b is further disposed on the support structure 111, and the second electrode 10b is insulated from the first electrode 10a by an insulating layer 110. The height of the support structure 111 may correspond to the height of the mesa structure 108. It should be noted that the structure of the support structure 111 is similar to that of the mesa structure 108, and the active region in the support structure 111 is not formed with the light emitting hole, so that the support structure 111 cannot emit light. The two first electrodes 10a on the two mesa structures 108 are separated from each other, and thus either mesa structure 108 can be lit. Since the laser chip is of a back surface structure, the laser beam emitted from the light emitting hole exits through the semiconductor substrate 101.

As shown in fig. 9, in the present embodiment, a thinning process is performed on the semiconductor substrate 101, then the adhesive layer 20 is disposed on the upper surface of the semiconductor substrate 101, the optical element 30 is disposed on the adhesive layer 20, the thickness of the adhesive layer 20 may be 20 to 1000 micrometers, for example, 60 micrometers, and the thickness of the adhesive layer 20 may be greater than the thickness of the optical element 30. The laser beam may pass through the adhesive layer 20. The optical element 30 comprises a first layer of material 31, a second layer of material 32 and a transparent top liner 33. The contact surface of the first material layer 31 and the second material layer 32 forms an optical pattern 34, and the optical pattern 34 may have an irregular undulation. The refractive index of the first material layer 31 may be smaller than the refractive index of the second material layer 32. In the present embodiment, the optical element 30 is fixed on the semiconductor substrate 101 by the adhesive layer 20, so that the distance between the light emitting hole and the optical element 30 is increased, and therefore, the light spot impinging on the optical element becomes large, the number of microstructures of which the light spot covers the optical element becomes large, and therefore, the uniformity of the far field of the emission end is better.

As shown in fig. 8 to 9, in the present embodiment, the laser in fig. 8 is of a front structure, the laser in fig. 9 is of a rear structure, and the optical elements 30 in fig. 8 to 9 are fixed on the laser chip by the adhesive layer 20. The lasers in fig. 8-9 each include two mesa structures 108.

As shown in fig. 8-9, in the present embodiment, an optical pattern 34 may be formed on top of the first material layer 31, for example, by means of nano-imprinting or etching. As can be seen in fig. 8-9, the optical pattern 34 is a non-periodic relief, and is a non-regular relief.

As shown in fig. 10, in some embodiments, the shape of the optical pattern 34 may also be a regular relief, and the optical pattern 34 is also a periodic relief. For example, the optical pattern in fig. 10 is a regular arc-shaped structure, and is a periodic arc-shaped structure.

As shown in fig. 11-12, this embodiment also proposes another laser, each of which includes a mesa structure 108 therein. As can be seen from the figure, a plurality of mesa structures 108 are disposed on the semiconductor substrate 101, and dicing streets 101c are also disposed between the mesa structures 108 on the upper surface 101a of the semiconductor substrate 101 in the mesa structures 108. The streets 101c may be aligned in a first direction and a second direction, the first direction may be an X direction, and the second direction may be a Y direction. Of course, in some embodiments, the cutting street 101c may also be located on the second surface 101 b. It should be noted that the cutting line 101c in fig. 2 is only for illustration. In the present embodiment, after cutting by the scribe line 101c, a plurality of lasers, which may be vertical cavity surface emitting lasers, may be formed.

As shown in fig. 13, the present embodiment also proposes another laser, which includes a mesa structure 108, and the mesa structure 108 includes a first reflective layer 102, an active layer 103, and a second reflective layer 104. The active layer 103 includes a first semiconductor layer 1031, an active region 1032, and a second semiconductor layer 1033. The first semiconductor layer 1031 is positioned on the first reflective layer 102, the active region 1032 is positioned on the first semiconductor layer 1031, and the second semiconductor layer 1033 is positioned on the active region 1032. The second reflective layer 104 is on the second semiconductor layer 1032. A current confinement layer 106 is also formed in the active region 1032, and a light-emitting aperture is defined by the current confinement layer 106.

As shown in fig. 13, in the present embodiment, a conductive contact layer 105 is further disposed on the mesa structure 108, the conductive contact layer 105 is located on the second reflective layer 104, a first electrode 10a is further disposed on the mesa structure 108, the first electrode 10a extends from the top of the mesa structure 108 to the first reflective layer 102, and the first electrode 10a is in contact with the conductive contact layer 105. An insulating layer 110 is also provided between the first electrode 10a and the mesa structure 108. A second electrode 10b is also provided on the second surface of the first reflective layer 102.

As shown in fig. 13, in the present embodiment, since the reflectance of the first reflective layer 102 is larger than that of the second reflective layer 104, the laser beam exits from the second reflective layer 102, and thus the mesa structure 108 is a front surface structure.

As shown in fig. 13, an adhesive layer 20 is further disposed on the mesa structure 108, and the bottom of the adhesive layer 20 is in contact with the first electrode 102 on the first reflective layer 102, that is, the first material layer 31 covers the entire active layer 103 and the second reflective layer 104. An optical element 30 is also disposed over the adhesive layer 20, the optical element 30 including a first material layer 31, a second material layer 32, and a transparent top liner 33. A first material layer 31 is positioned on the adhesive layer 20, a second material layer 32 is positioned on the first material layer 31, and a transparent top liner 33 is positioned on the second material layer 32. The optical pattern 34 is provided on the surface of the first material layer 31 in contact with the second material layer 32, and the shape of the optical pattern 34 is a relief, specifically, the shape of the optical pattern 34 is an irregular relief. In this embodiment, the first material layer 31 may be a dielectric material with a low refractive index, the refractive index of the first material layer 31 may be between 1.0 and 2.0, and the material of the first material layer 31 may be silicon dioxide or silicon nitride or a polymer material. The laser beam emitted from the light emitting hole may exit through the first material layer 31, and thus the path of the laser beam may be extended. Second material layer 32 may be a high index of refraction dielectric material. The refractive index of the second material layer 32 may be between 1.5-4.0, and the refractive index of the second material layer 32 may be smaller than the refractive index of the first material layer 31. The thickness of the second material layer 32 may be smaller than the thickness of the first material layer 31. The material of the second material layer 32 may be silicon dioxide or silicon nitride or a polymer material. Second material layer 32 may also be a one-layer or multi-layer structure.

As shown in fig. 13, in the present embodiment, the lower surface of the second material layer 32 is matched with the optical pattern 34, so that the optical pattern 34 can also be said to form a surface microstructure of the second material layer 32. The microstructure of the second material layer 32 can perform functions such as laser beam collimation, beam shaping (beam shaping) or beam steering (beam steering), and achieve far-field distribution, such as flat-top distribution and dot cloud distribution. After forming the second material layer 32, a transparent top liner 33 is disposed on the second material layer 32, and the transparent top liner 33 is used to protect the second material layer 32. The transparent top substrate 33 may be a sapphire substrate or a glass substrate. In the present embodiment, the first material layer 31, the second material layer 32, and the transparent top liner 33 are defined as the optical element 30. In the present embodiment, the optical element 30 may be any one of a diffuser, a refractive optical element, a diffractive optical element, a grating structure, a superstructure, and a super surface. In forming this laser, a mesa structure is first formed on a semiconductor substrate, and after forming an optical element, the semiconductor substrate needs to be peeled off. The manufacturing method of the laser can be seen in fig. 1.

As shown in fig. 14, the present embodiment also proposes another laser, and the structure of the laser in fig. 14 is similar to that of the laser in fig. 13, except that: the laser in fig. 14 is not provided with a transparent top substrate, and the mesa structure 108 is provided on the upper surface of the semiconductor substrate 101, and the second electrode 10b is located on the lower surface of the semiconductor substrate 101. That is, the semiconductor substrate 101 is not peeled off when the laser is formed.

As shown in fig. 15, the present embodiment also proposes another laser, and the structure of the laser in fig. 15 is similar to that of the laser in fig. 13, except that: the first electrode 10a and the second electrode 10b are located on the same side of the first reflective layer 102.

As shown in fig. 16, this embodiment also proposes another laser, and the structure of the laser in fig. 16 is similar to that of the laser in fig. 15, except that: the laser in fig. 16 is not provided with a transparent top substrate, and the mesa structure 108 is provided on the upper surface of the semiconductor substrate 101, that is, the semiconductor substrate 101 is not peeled off at the time of forming the laser.

As shown in fig. 13-16, in the present embodiment, the laser is a front emission structure, that is, the laser beam emitted by the laser exits through the optical element 30 or the second material layer 32.

As shown in fig. 17, in the present embodiment, another laser is also proposed, in which a mesa structure 108 is formed on the upper surface of the semiconductor substrate 101, and the first electrode 10a and the second electrode 10b are both located on the upper surface of the semiconductor substrate 101. An adhesive layer 20 and an optical element 30 are provided on the lower surface of the semiconductor substrate 101.

As shown in fig. 18, in the present embodiment, another laser is also proposed, in which a mesa structure 108 is formed on the upper surface of the semiconductor substrate 101, and the first electrode 10a and the second electrode 10b are both located on the upper surface of the semiconductor substrate 101. An adhesive layer 20 and a first material layer 31 and a second material layer 32 are provided on the lower surface of the semiconductor substrate 101.

As shown in fig. 17 to 18, in the present embodiment, the laser is a back-emission structure, and a laser beam emitted by the laser exits through the optical element 30 or the second material layer 32. When the adhesive layer 20 is fixed to the semiconductor substrate 101, it is necessary to perform thinning processing on the semiconductor substrate 101. Meanwhile, when the first electrode 10a is formed, the first electrode 10a completely covers the top of the mesa structure 108, and the first electrode 10a and the conductive contact layer are formed in one step.

As shown in fig. 19-20, fig. 19-20 are schematic views of an excitation laser array. As can be seen from fig. 19 and 20, when the laser array is excited, the laser beam emitted from the light emitting hole exits through the first material layer 31, and due to the existence of the first material layer 31, the distance between the light emitting hole and the optical pattern is increased, that is, the path of the laser beam is lengthened, so that the spot hitting on the optical pattern is enlarged, the number of the spots covering the optical pattern is increased or the area is enlarged, and therefore, the uniformity of the far field at the emitting end is better. The laser array in fig. 19 has a front structure, and the laser array in fig. 20 has a back structure.

As shown in fig. 21, the present embodiment further provides an electronic device 40, where the electronic device 40 includes a light emitting module 41 and a light receiving module 42. At least one laser is disposed in the light emitting module 41, the laser is used for emitting a laser beam, the laser may be integrated with an optical element, and the structure of the laser may refer to fig. 7 or fig. 8 or fig. 13 or fig. 14. When the laser beam is reflected by the target object, a reflected beam is formed. The light receiving module 42 is used for receiving the reflected light beam and forming a sensing signal. The electronic device 40 may be a three-dimensional perception device.

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 method of fabricating a laser, comprising:

a groove is arranged between two adjacent platform-shaped structures, and the cutting path is positioned in the groove;

wherein the optical element comprises:

a first material layer;

a second material layer on the first material layer;

a transparent top liner positioned on the second material layer;

2. The method of manufacturing of claim 1, wherein the mesa structure is on the substrate, the mesa structure comprising:

a first reflective layer having a first surface and a second surface;

an active layer on the first surface;

a second reflective layer on the active layer.

3. The method of manufacturing according to claim 2, wherein the optical element is located on the first surface of the first reflective layer when the laser is a front-side structure; when the laser is in a back-side configuration, the optical element is located on the second surface of the first reflective layer.

4. The manufacturing method according to claim 2, wherein when the laser is a front-surface structure, at least one through hole that communicates the first surface and the second surface is formed on the first reflective layer before the optical element is formed; and the first electrode on the mesa structure is positioned in the through hole.

5. The method of manufacturing according to claim 4, further comprising, after forming the optical element, peeling off the substrate and depositing a first electrode on a second surface of the first reflective layer, the first electrode on the second surface being connected to the first electrode in the through hole.

6. The method of manufacturing according to claim 2, wherein when the laser is a front-side structure, the laser further comprises a second electrode on the first surface or the second surface of the first reflective layer.

7. The manufacturing method according to claim 2, wherein when the laser is a backside structure, the substrate is further subjected to a thinning process before the optical element is formed.

8. A method of manufacturing according to claim 2, wherein when the laser is a back-side structure, the laser further comprises a first electrode on the mesa structure and a second electrode on the first reflective layer or support structure.

9. A laser, comprising:

a groove is arranged between two adjacent platform-shaped structures, and a cutting path is positioned in the groove;

wherein the optical element comprises:

a first material layer;

a second material layer on the first material layer;

a transparent top liner positioned on the second material layer;

10. An electronic device, comprising:

the light receiving module is used for receiving the reflected light beam;

wherein the optical element comprises:

a first material layer;

a second material layer on the first material layer;

a transparent top liner positioned on the second material layer;