阅读说明：本技术 一种低翘曲半导体激光器及其制备方法 (Low-warpage semiconductor laser and preparation method thereof ) 是由 赵武 刘恒 王俊 谷飞 苗霈 于 2021-09-14 设计创作，主要内容包括：本发明提供一种低翘曲半导体激光器及其制备方法,包括衬底、设置于衬底一侧的外延结构层和设置于所述衬底远离所述外延结构层的一侧表面的防翘曲层。位于所述外延结构层的一侧表面的防翘曲层使衬底内部产生第二内应力,所述第二内应力能够平衡外延结构层形成后衬底内部产生的第一内应力,从而降低所述衬底的翘曲程度,增大了在转移、测试和切割过程中衬底的各个位置受力的均匀程度,进而降低了破片率,提高了半导体激光器的良率。(The invention provides a low-warpage semiconductor laser and a preparation method thereof. The anti-warping layer on the surface of one side of the epitaxial structure layer enables a second internal stress to be generated inside the substrate, the second internal stress can balance a first internal stress generated inside the substrate after the epitaxial structure layer is formed, so that the warping degree of the substrate is reduced, the uniform degree of stress of each position of the substrate in the transferring, testing and cutting processes is increased, the wafer breakage rate is reduced, and the yield of the semiconductor laser is improved.)

1. A low warpage semiconductor laser, comprising:

a substrate;

an epitaxial structure layer arranged on one side of the substrate;

and the anti-warping layer is arranged on the surface of one side, far away from the epitaxial structure layer, of the substrate.

2. The low-warpage semiconductor laser as claimed in claim 1, wherein the material of the warpage preventing layer is Ti/W alloy, the mass percentage of Ti element in the Ti/W alloy is 5-20%, and the rest is W element.

3. The low warpage semiconductor laser of claim 1, wherein the material of the warpage preventing layer is Ni/W alloy, the mass percentage of Ni element in the Ni/W alloy is 5% -20%, and the rest is W element.

4. A low warp semiconductor laser as claimed in claim 2 or 3 wherein the thickness of the anti-warp layer is 30nm-450 nm.

5. A low warp semiconductor laser as claimed in claim 1 wherein said anti-warp layer comprises a titanium layer and a tungsten layer in contact with each other, and said titanium layer is located between said substrate and said tungsten layer; the thickness of the titanium layer is 15nm-100nm, and the thickness of the tungsten layer is 30nm-450 nm.

6. The low warp semiconductor laser of claim 1, wherein the warpage prevention layer comprises a nickel layer and a tungsten layer in contact with each other, and the nickel layer is located between the substrate and the tungsten layer; the thickness of the nickel layer is 15nm-100nm, and the thickness of the tungsten layer is 30nm-450 nm.

7. A low warp semiconductor laser as claimed in claim 1 wherein the thickness of the substrate is 80 μm-180 μm.

8. A low warp semiconductor laser as claimed in claim 1 further comprising: and the first electrode is arranged on the surface of one side, far away from the substrate, of the anti-warping layer.

9. A method for manufacturing a low warpage semiconductor laser, comprising:

providing an initial substrate;

forming an epitaxial structure layer on one side surface of the initial substrate;

after the epitaxial structure layer is formed, thinning the initial substrate to obtain a substrate;

and forming a warp-proof layer on the surface of one side of the substrate, which is far away from the epitaxial structure layer.

10. A method for fabricating a low warp semiconductor laser as claimed in claim 9 further comprising:

after the anti-warping layer is formed, a first electrode is formed on the surface of one side, away from the substrate, of the anti-warping layer.

Technical Field

The invention relates to the technical field of lasers, in particular to a low-warpage semiconductor laser and a preparation method thereof.

Background

A Vertical-Cavity surface-Emitting Laser (VCSEL) is a new semiconductor Laser with a Laser Emitting direction perpendicular to the chip surface. Compared with an edge-emitting Laser (EEL), the vertical cavity surface-emitting Laser has many advantages, including low threshold current, good stability, long service life, circularly symmetric light spots, high fiber coupling efficiency, high modulation rate, easy two-dimensional integration, and the like. Therefore, the vertical cavity surface emitting laser has been widely used in various high-efficiency and high-speed optical communication networks as a main light source device.

However, during the fabrication of the vertical cavity surface emitting laser, the substrate may warp. The warped substrate is prone to chipping due to uneven stress during transfer, testing and dicing, reducing the yield of such semiconductor lasers.

Disclosure of Invention

Therefore, the technical problem to be solved by the present invention is to overcome the defect of low yield of the conventional semiconductor laser, thereby providing a low warpage semiconductor laser and a method for manufacturing the same.

The invention provides a low warpage semiconductor laser, including: a substrate; an epitaxial structure layer arranged on one side of the substrate; and the anti-warping layer is arranged on the surface of one side, far away from the epitaxial structure layer, of the substrate.

Optionally, the anti-warping layer is made of a Ti/W alloy, the mass percentage of Ti elements in the Ti/W alloy is 5% -20%, and the balance is W elements.

Optionally, the anti-warping layer is made of a Ni/W alloy, the mass percentage of Ni elements in the Ni/W alloy is 5% -20%, and the balance is W elements.

Optionally, the thickness of the anti-warping layer is 30nm-450 nm.

Optionally, the warpage preventing layer includes a titanium layer and a tungsten layer that are in contact with each other, and the titanium layer is located between the substrate and the tungsten layer; the thickness of the titanium layer is 15nm-100nm, and the thickness of the tungsten layer is 30nm-450 nm.

Optionally, the warping prevention layer includes a nickel layer and a tungsten layer that are in contact with each other, and the nickel layer is located between the substrate and the tungsten layer; the thickness of the nickel layer is 15nm-100nm, and the thickness of the tungsten layer is 30nm-450 nm.

Optionally, the substrate has a thickness of 80 μm to 180 μm.

Optionally, the low warpage semiconductor laser further includes: and the first electrode is arranged on the surface of one side, far away from the substrate, of the anti-warping layer.

The invention also provides a preparation method of the low-warpage semiconductor laser, which comprises the following steps: providing an initial substrate; forming an epitaxial structure layer on one side surface of the initial substrate; after the epitaxial structure layer is formed, thinning the initial substrate to obtain a substrate; and forming a warp-proof layer on the surface of one side of the substrate, which is far away from the epitaxial structure layer.

Optionally, the method for manufacturing a low-warpage semiconductor laser further includes: after the anti-warping layer is formed, a first electrode is formed on the surface of one side, away from the substrate, of the anti-warping layer.

The technical scheme of the invention has the following advantages:

1. according to the low-warpage semiconductor laser, the anti-warpage layer positioned on the surface of one side of the epitaxial structure layer enables a second internal stress to be generated inside the substrate, and the second internal stress can balance a first internal stress generated inside the substrate after the epitaxial structure layer is formed, so that the warpage degree of the substrate is reduced, the stress uniformity degree of each position of the substrate in the transferring, testing and cutting processes is increased, the chip breaking rate is reduced, and the yield of the semiconductor laser is improved.

2. According to the low-warpage semiconductor laser provided by the invention, the magnitude of the second internal stress is regulated and controlled by limiting the mass percent of the Ti element in the Ti/W alloy and the mass percent of the Ni element in the Ni/W alloy, so that the second internal stress is balanced with the first internal stress, and the warpage degree of the substrate is reduced. Meanwhile, Ti or Ni has an adhesion effect, so that the anti-warping layer is stably adhered to the surface of the substrate.

3. According to the low-warpage semiconductor laser, the thickness of the anti-warpage layer is limited to be 30nm-450nm, and the size of the second internal stress is limited so as to reduce the warpage degree of the substrate. Specifically, when the thickness of the warp-preventing layer is too small, the second internal stress is too small, and the warp degree of the substrate cannot be reduced; when the thickness of the warp-preventing layer is too large, the second internal stress is too large, and the substrate has a risk of reverse warp.

4. According to the low-warpage semiconductor laser, the thickness of the titanium layer and the tungsten layer or the thickness of the nickel layer and the tungsten layer is limited to regulate and control the magnitude of the second internal stress, so that the second internal stress is balanced with the first internal stress, and the warpage degree of the substrate is reduced. Meanwhile, the titanium layer or the nickel layer has an adhesion effect, so that the anti-warping layer is stably adhered to the surface of the substrate.

5. According to the preparation method of the low-warpage semiconductor laser, the initial substrate is thinned after the epitaxial structure layer is formed on the surface of one side of the initial substrate, the substrate is obtained, the anti-warpage layer is formed on the surface of the side, far away from the epitaxial structure layer, of the substrate, second internal stress is generated inside the substrate, and the second internal stress can balance the first internal stress generated inside the substrate after the epitaxial structure layer is formed, so that the warpage degree of the substrate is reduced, the stress uniformity of all positions of the substrate in the transferring, testing and cutting processes is increased, the breakage rate is reduced, and the yield of the semiconductor laser is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic cross-sectional view of a semiconductor laser;

fig. 2 is a schematic cross-sectional structure diagram of a low warpage semiconductor laser provided in an embodiment of the present invention;

fig. 3 is a process flow diagram of a low warpage semiconductor laser provided in an embodiment of the present invention;

fig. 4-6 are schematic structural diagrams of a low warpage semiconductor laser provided in an embodiment of the present invention during fabrication.

Description of reference numerals:

1-a first electrode; 2-anti-warping layer; 3-a substrate; 31-an initial substrate; 4-an epitaxial structure layer; 41-a first bragg mirror layer; 42-an active layer; 43-a second bragg mirror layer; 5-a second electrode.

Detailed Description

As shown in fig. 1, a semiconductor laser includes: a substrate 3'; an epitaxial structure layer 4' disposed on one side of the substrate 3', the epitaxial structure layer 4' including: the epitaxial structure layer 4 'is provided with a plurality of grooves penetrating into the first bragg reflector layer 41', so that the epitaxial structure layer is divided into a plurality of mesa structures; the first electrode 1 'is arranged on the surface of one side, away from the epitaxial structure layer 4', of the substrate 3', and the first electrode 1' can be a germanium-gold-nickel-gold structure (Ge/Au/Ni/Au), a gold-germanium-nickel alloy and gold (AuGeNi/Au) structure, a gold-germanium alloy (AuGe) or a germanium-titanium-platinum (Ge/Ti/Pt/Au) structure; and the second electrode 5' is arranged on the surface of one side of the mesa structure, which is far away from the substrate 3', and the second electrode 5' is annular.

Due to lattice mismatch of the epitaxial structure layer 4 'and the substrate 3', a first internal stress is generated inside the substrate after the epitaxial structure layer 4 'is grown on the surface of the substrate 3', and the first internal stress is compressive stress; meanwhile, in order to make the first bragg mirror layer 41' and the second bragg mirror layer 43' reach sufficient reflectivity, the number of groups of high refractive index layers and low refractive index layers in the first bragg mirror layer 41' and the second bragg mirror layer 43' at least needs to reach more than 20, and the increase of the number of groups of high refractive index layers and low refractive index layers can cause the accumulation of first internal stress in the substrate, so that the substrate 3' is warped, and the middle area protrudes upwards; after thinning the substrate 3', the degree of warpage becomes greater, and the height of warpage can reach several millimeters. The warped wafer is easy to crack due to uneven stress in the transferring, testing and cutting processes, meanwhile, the wafer with overlarge warpage is difficult to focus in the microscopic examination process, vacuum suction is needed to forcedly flatten the wafer, the wafer is easy to crack and damage due to overlarge stress, and the yield of the semiconductor laser is reduced.

On the basis, the invention provides a low-warpage semiconductor laser, which comprises a substrate; an epitaxial structure layer arranged on one side of the substrate; and the anti-warping layer is arranged on the surface of one side, far away from the epitaxial structure layer, of the substrate. The low-warpage semiconductor laser has high yield.

The technical scheme of the invention is clearly and completely described in the following with reference to the accompanying drawings.

It is to be understood that the terms "upper", "lower", "inner", "outer", and the like, as used herein, are used in a generic and descriptive sense only and not for purposes of limitation, the terms "upper", "lower", "inner", "outer", and the like, as used herein, refer to an orientation or positional relationship illustrated in the drawings and are used to facilitate describing the invention herein and to simplify the description. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

Referring to fig. 2, the present embodiment provides a low warpage semiconductor laser including: a substrate 3; an epitaxial structure layer 4 disposed on one side of the substrate 3; and the anti-warping layer 2 is arranged on the surface of one side, far away from the epitaxial structure layer 4, of the substrate 3.

Among the above-mentioned low warpage semiconductor laser, be located the anti-warping layer 2 of one side surface of epitaxial structure layer 4 makes the inside second internal stress that produces of substrate 3, the inside first internal stress that produces of substrate 3 after epitaxial structure layer 4 formation can be balanced to the second internal stress to reduce the warping degree of substrate 3 has increased the even degree of each position atress of substrate in transfer, test and cutting process, and then has reduced the broken rate, has improved semiconductor laser's yield.

Specifically, the reason why the second internal stress is generated inside the substrate in this embodiment is that:

(1) the difference of the linear expansion coefficients of the anti-warp layer 2 and the substrate 3 is as follows: in the process of depositing the anti-warping layer 2 on the substrate 3, the temperature in the chamber where the substrate is located is high; when the anti-warping layer 2 is deposited to the required thickness, the temperature of the chamber is reduced; because the linear expansion coefficient of the anti-warping layer 2 is different from that of the substrate 3, the volume shrinkage degree of the anti-warping layer 2 is different from that of the substrate 3, and therefore second internal stress is generated inside the substrate;

(2) mismatch of the interface of the anti-warp layer 2 and the substrate 3: the lattice structure of the warp-preventing layer 2 is different from that of the substrate 3; therefore, when the anti-warp layer 2 is deposited on the surface of the substrate 3 on the side far away from the epitaxial structure layer 4, second internal stress is generated inside the substrate.

In this embodiment, the material of the anti-warp layer 2 is Ti/W alloy, the mass percentage of Ti element in the Ti/W alloy is 5% -20%, and the rest is W element; or the anti-warping layer 2 is made of Ni/W alloy, the mass percent of Ni element in the Ni/W alloy is 5% -20%, and the balance is W element. Illustratively, the mass percentage of the Ti element in the Ti/W alloy may be 5%, 7.5%, 10%, 12.5%, 15%, 17.5%, or 20%; the mass percentage of the Ti element in the Ti/W alloy can be 5%, 7.5%, 10%, 12.5%, 15%, 17.5% or 20%. And regulating the magnitude of the second internal stress by limiting the mass percent of the Ti element in the Ti/W alloy and the mass percent of the Ni element in the Ni/W alloy so as to balance the second internal stress with the first internal stress, thereby reducing the warping degree of the substrate. Meanwhile, Ti or Ni has an adhesion effect, so that the anti-warping layer is stably adhered to the surface of the substrate. In addition, the warping prevention layer also has the effects of metal shielding and water vapor isolation, and can avoid that the substrate 3 deviates from one side surface of the epitaxial structure layer 4 is corroded by water vapor.

Further, the thickness of the anti-warping layer 2 is 30nm-450 nm. Illustratively, the thickness of the anti-warp layer 2 may be 30nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, or 450 nm. By defining the thickness of the warp-preventing layer 2 to be 30nm to 450nm, the magnitude of the second internal stress is defined to reduce the degree of warp of the substrate. Specifically, when the thickness of the warp-preventing layer 2 is too small, the second internal stress is too small, and the warp degree of the substrate cannot be reduced; when the thickness of the anti-warp layer 2 is too large, the second internal stress is too large, and the substrate has a risk of reverse warp, the deposition time is increased, and the preparation cost is increased.

In the present embodiment, the material of the substrate 3 may be gallium arsenide (GaAs), indium phosphide (InP), or gallium nitride (GaN), and has a thickness of 80 μm to 180 μm; illustratively, the thickness of the substrate 3 may be 80 μm, 100 μm, 120 μm, 160 μm, or 180 μm.

In this embodiment, the epitaxial structure layer 4 includes: a first bragg reflector layer 41, an active layer 42 and a second bragg reflector layer 43 which are stacked, wherein the first bragg reflector layer 41 is located between the substrate 3 and the active layer 42; the epitaxial structure layer 4 is provided with a plurality of grooves penetrating into the first bragg reflector layer 41 to divide the epitaxial structure layer into a plurality of mesa structures. Specifically, the first bragg mirror layer 41 and the second bragg mirror layer 43 may both be of a gallium arsenide/aluminum arsenide (GaAs/AlAs) structure; the active layer 42 includes, but is not limited to, an indium gallium arsenide/gallium arsenide phosphide (InGaAs/GaAsP), gallium arsenide/aluminum gallium arsenide (GaAs/AlGaAs), indium gallium arsenide/gallium arsenide (InGaAs/GaAs), or indium gallium arsenide/aluminum gallium arsenide (InGaAs/AlGaAs) periodic multi-quantum well structure with a mesa diameter of 8 μm to 100 μm.

In this embodiment, the low warpage semiconductor laser further includes a first electrode 1 disposed on a surface of the warpage preventing layer 2 on a side away from the substrate 3. During the test of the semiconductor laser, the first electrode 1 is coated with solder to be electrically connected with a bonding wire connected with a test device. It should be understood that the contact force between the material of the anti-warping layer 2 provided in this embodiment and the solder is weak, and the solder cannot be stably coated on the surface of the first electrode 1, so that the normal test of the semiconductor laser is affected, and therefore, the first electrode 1 needs to be deposited to ensure that the solder is stably coated on the surface of the first electrode 1. Through the cooperation setting of first electrode 1 and anti-warping layer 2, make semiconductor laser not only have lower warpage degree, improved semiconductor laser's yield, still guaranteed semiconductor laser's normal test and use.

Further, the first electrode 1 may be a germanium gold nickel gold structure (Ge/Au/Ni/Au), a gold germanium nickel alloy and gold (AuGeNi/Au) structure, a gold germanium alloy (AuGe), a germanium titanium platinum (Ge/Ti/Pt/Au) structure, or a titanium gold (Ti/Au) structure. The thickness of the first electrode is 150nm-850 nm. Illustratively, the thickness of the first electrode 1 may be 150nm, 250nm, 350nm, 450nm, 550nm, 650nm, 750nm, or 850 nm.

In this embodiment, the low-warpage semiconductor laser further includes a second electrode 5 disposed on a side of the second bragg mirror layer 43 facing away from the substrate 3; specifically, the second electrode 5 is arranged on the mesa structure, the second electrode 5 is annular, and the low-warpage semiconductor laser emits light from the center of the second electrode 5, so as to obtain a circular laser beam; the second electrode 5 has an outer diameter of 5 μm to 30 μm, an inner diameter of 3 μm to 27 μm, and the second electrode 5 may be a titanium-gold alloy (Ti/Au) or a titanium-platinum-gold alloy (Ti/Pt/Au).

In this embodiment, the low-warpage semiconductor laser further includes a current confinement layer disposed between the active layer 42 and the second bragg mirror layer 43, and the current confinement layer is annular and disposed at an edge of the mesa structure. The current confinement layer functions to confine carriers.

Referring to fig. 3, the present embodiment further provides a method for manufacturing a low warpage semiconductor laser, including:

s1, providing an initial substrate 31;

s2, forming an epitaxial structure layer 4 on one side surface of the initial substrate 31;

s3, thinning the initial substrate 31 to obtain a substrate 3;

and S4, forming a warp-proof layer 2 on the surface of one side of the substrate 3 away from the epitaxial structure layer 4.

According to the preparation method of the low-warpage semiconductor laser, the anti-warpage layer is formed on the surface of one side, away from the epitaxial structure layer, of the substrate 3, so that second internal stress is generated inside the substrate 3, and the second internal stress can balance first internal stress generated inside the substrate 3 after the epitaxial structure layer is formed, so that the warpage degree of the substrate 3 is reduced, the stress uniformity of all positions of the substrate in the transferring, testing and cutting processes is increased, the breakage rate is reduced, and the yield of the semiconductor laser is improved.

The method for manufacturing the low warpage semiconductor laser will be described in detail with reference to fig. 4 to 6.

Referring to fig. 4, an epitaxial structure layer 4 is formed on one side surface of the initial substrate 31.

Specifically, the step of forming the epitaxial structure layer 4 on the surface of one side of the initial substrate 31 includes: sequentially forming a first Bragg reflector layer 41, an active layer 42 and a second Bragg reflector layer 43 on one side surface of the initial substrate 31 by adopting a metal organic chemical vapor deposition process, wherein the content of aluminum element in the first Bragg reflector layer 41 of partial layers contacting with the active layer 42 is more than 98%; depositing a second metal layer on the surface of the second bragg reflector layer 43 on the side away from the active layer 42, and then processing the second metal layer by using a photolithography process and a metal stripping process to obtain a second electrode 5; forming a dielectric layer covering the upper surface of the second electrode 5 and the second bragg reflector layer 43, and etching the dielectric layer by adopting a photoetching process and a dry etching process to obtain a mask layer; with the mask layer as a mask, etching the first bragg reflector layer 41, the active layer 42 and the second bragg reflector layer 43 to obtain a plurality of grooves, wherein the grooves penetrate through the first bragg reflector layer 41 to divide the epitaxial structure layer into a plurality of mesa structures; subjecting the mesa structure to a dilute acid or dilute base treatment, followed by wet oxidation of the mesa structure to obtain a current confinement layer.

Specifically, the thickness of the initial substrate 31 is 300 μm to 700 μm, and the initial substrate 31 may have a thickness of 300 μm, 325 μm, 350 μm, 375 μm, 600 μm, 625 μm, 650 μm, 675 μm, or 700 μm. The dielectric layer can be made of silicon nitride, and the thickness of the dielectric layer is 100nm-1000 nm. Illustratively, the dielectric layer may have a thickness of 100nm, 200nm, 300nm, 500nm, 800nm, 900nm, or 1000 nm. The dilute acid can be HCl, and the dilute base can be NH₄And (5) OH. In the wet oxidation process, the first bragg mirror layer 41 having a high aluminum element content is oxidized from the edge toward the inside, thereby forming a current confinement layer.

After obtaining the current limiting layer, the method further comprises the following steps: depositing a passivation layer on the front surface of the semiconductor laser; the second electrode 5 is subsequently exposed by a photolithographic process; depositing a second metal layer on the front surface of the semiconductor laser; then obtaining a metal interconnection pattern through a photoetching process; and then obtaining a metal interconnection structure by etching the second metal layer.

Specifically, the passivation layer may be made of silicon nitride, and the thickness of the passivation layer is 100nm to 1000 nm. Illustratively, the thickness of the passivation layer may be 100nm, 200nm, 300nm, 500nm, 800nm, 900nm, or 1000 nm. The second metal layer is made of TiAu alloy, and the required corrosive liquid comprises gold corrosive liquid and titanium corrosive liquid.

After obtaining the metal interconnection structure, the method further comprises the following steps: obtaining an electroplating pattern on the front surface of the semiconductor laser through a photoetching process; metal is then electroplated within the plating pattern by an electroplating process. Specifically, the metal pattern formed by electroplating is made of gold (Au) and has a thickness of 1-8 μm.

Referring to fig. 5, the initial substrate 31 is thinned, resulting in a substrate 3.

Specifically, the step of thinning the initial substrate 31 includes: providing a hard substrate (not shown in the figure), wherein the thickness of the hard substrate is 0.3mm-1 mm; bonding the front surface of the semiconductor laser on the hard substrate by a bonding process; and thinning the initial substrate 31 by adopting a chemical mechanical polishing process until the thickness of the initial substrate 31 is 80-180 μm, and obtaining the substrate 3. The material of the hard base plate can be a sapphire substrate.

Referring to fig. 5, a warp prevention layer 2 is formed on a surface of the substrate 3 on a side away from the epitaxial structure layer 4.

Specifically, a magnetron sputtering process is adopted to form the anti-warping layer 2 on the surface of one side of the substrate 3, which is far away from the epitaxial structure layer 4.

Referring to fig. 6, after the anti-warp layer 2 is formed, a first electrode 1 is formed on a surface of the anti-warp layer 2 on a side away from the substrate 3.

After the first electrode 1 is formed, the hard substrate is separated from the front surface of the semiconductor laser.

Example 2

The present embodiment provides a low warpage semiconductor laser, which is different from the low warpage semiconductor laser provided in embodiment 1 in that: the anti-warping layer comprises a titanium layer and a tungsten layer which are in mutual contact, and the titanium layer is located between the substrate and the tungsten layer; the thickness of the titanium layer is 15nm-100nm, and the thickness of the tungsten layer is 30nm-450 nm.

Example 3

The present embodiment provides a low warpage semiconductor laser, which is different from the low warpage semiconductor laser provided in embodiment 1 in that: the anti-warping layer comprises a nickel layer and a tungsten layer which are in contact with each other, and the nickel layer is positioned between the substrate and the tungsten layer; the thickness of the nickel layer is 15nm-100nm, and the thickness of the tungsten layer is 30nm-450 nm.

Example 4

The present embodiment provides a low warpage semiconductor laser, including:

the substrate is a gallium arsenide substrate, and the thickness of the substrate is 100 microns;

set up in the epitaxial structure layer of substrate one side, epitaxial structure layer includes: the array substrate comprises a substrate, a first Bragg reflector layer, an active layer and a second Bragg reflector layer, wherein the first Bragg reflector layer, the active layer and the second Bragg reflector layer are stacked; the epitaxial structure layer is provided with a plurality of grooves penetrating into the first Bragg reflector layer so as to divide the epitaxial structure layer into a plurality of table-board structures; the first Bragg reflector layer and the second Bragg reflector layer are both of gallium arsenide/aluminum arsenide (GaAs/AlAs) structures, the active layer is gallium arsenide/aluminum gallium arsenide (GaAs/AlGaAs), and the thickness of the epitaxial structure layer is 2 microns;

the anti-warping layer is arranged on the surface of one side, far away from the epitaxial structure layer, of the substrate, the anti-warping layer is made of Ti/W alloy, the mass percentage of Ti elements in the Ti/W alloy is 5%, and the thickness of the anti-warping layer is 30 nm.

The first electrode is arranged on the surface of one side, away from the substrate, of the anti-warping layer, the first electrode is made of gold-germanium-nickel alloy (Au/Ge/Ni), and the thickness of the first electrode is 150 nm;

and the second electrode is arranged on the mesa structure, the material of the second electrode is titanium alloy, the inner diameter of the second electrode 5 is 10 micrometers, the outer diameter of the second electrode is 20 micrometers, and the thickness of the second electrode is 150 nm.

Example 5

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 4 only in that: the mass percentage of Ti element in the Ti/W alloy is 20 percent.

Example 6

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 4 only in that: the thickness of the anti-warping layer is 450 nm.

Example 7

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 4 only in that: the anti-warping layer is made of Ni/W alloy, and the mass percentage of Ni elements in the Ni/W alloy is 5%.

Example 8

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 4 only in that: the anti-warping layer comprises a titanium layer and a tungsten layer which are in mutual contact, and the titanium layer is located between the substrate and the tungsten layer; the thickness of the titanium layer is 50nm, and the thickness of the tungsten layer is 200 nm.

Example 9

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 4 only in that: the anti-warping layer comprises a titanium layer and a tungsten layer which are in mutual contact, and the titanium layer is located between the substrate and the tungsten layer; the thickness of the titanium layer is 15nm, and the thickness of the tungsten layer is 450 nm.

Example 10

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 4 only in that: the anti-warping layer comprises a titanium layer and a tungsten layer which are in mutual contact, and the titanium layer is located between the substrate and the tungsten layer; the thickness of the titanium layer is 100nm, and the thickness of the tungsten layer is 30 nm.

Example 11

The present embodiment provides a low warpage semiconductor laser which differs from the low warpage semiconductor laser provided in embodiment 6 only in that: the anti-warping layer comprises a nickel layer and a tungsten layer which are in contact with each other, and the nickel layer is positioned between the substrate and the tungsten layer; the thickness of the nickel layer is 50nm, and the thickness of the tungsten layer is 200 nm.

Comparative example 1

This comparative example provides a semiconductor laser that differs from the low-warpage semiconductor laser provided in example 4 only in that: the semiconductor laser device in this comparative example was not provided with the warpage preventing layer.

Test examples

Comparative example 4 to the degree of warpage of example 11 and comparative example 1. The warping degree is as follows from small to large: example 8, example 11, example 5, example 4, example 7, example 6, example 9, example 10, comparative example 1.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.