CN113594846A

CN113594846A - Semiconductor laser and preparation method thereof

Info

Publication number: CN113594846A
Application number: CN202110855578.5A
Authority: CN
Inventors: 翟鲲鹏; 穆春元; 李明; 祝宁华
Original assignee: Institute of Semiconductors of CAS
Current assignee: Institute of Semiconductors of CAS
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2021-11-02

Abstract

A semiconductor laser and its preparation method, wherein, the semiconductor laser includes N electrode, N-type substrate, N-type lower limiting layer, N-type lower waveguide layer, active region, P-type upper waveguide layer, P-type upper limiting layer and P electrode that grow sequentially from bottom to top; wherein the N-type substrate includes a reserved space.

Description

Semiconductor laser and preparation method thereof

Technical Field

The invention relates to the fields of optical communication, photoelectron integration, high-speed semiconductor lasers and the like, in particular to a semiconductor laser based on a substrate hollowing technology and a preparation method thereof.

Background

With the increasing proliferation of mobile internet, cloud computing and big data, emerging applications such as 5G communication are emerging continuously, and the demand for high-speed data transmission is increasingly strong. In the backbone network and the next generation data center, the electronic chip encounters a rate bottleneck, and the optoelectronic chip becomes a development key point due to its low power consumption and high bandwidth characteristics. Aiming at the requirement of the existing high-speed optical communication, the direct modulation laser is widely applied to the optical communication due to the characteristics of low cost and easy processing. However, the bandwidth of the directly modulated laser is always a bottleneck for limiting the speed of the directly modulated laser, and the increase of the bandwidth directly improves the communication speed, so that the research on the high-speed directly modulated laser is crucial to the optical communication industry.

In the course of implementing the disclosed concept, the inventors found that high-speed directly-tuned lasers mostly focus on electrode optimization and active region optimization and structural design, and the bandwidth improvement thereof depends mostly on the growth of semiconductor materials and the matching of later electrodes, and the bandwidth improvement thereof enters the bottleneck.

Disclosure of Invention

In view of the above, the present disclosure provides a semiconductor laser based on a substrate hollowing technique and a method for manufacturing the same, so as to partially solve the problem that the bandwidth of a direct modulation laser is difficult to be increased.

According to an embodiment of the present disclosure, there is provided a semiconductor laser including an N electrode, an N-type substrate, an N-type lower confinement layer, an N-type lower waveguide layer, an active region, a P-type upper waveguide layer, a P-type upper confinement layer, and a P electrode grown in this order from bottom to top; wherein the N-type substrate includes a reserved space.

According to an embodiment of the present disclosure, the reserved space is disposed right below the active region.

According to the embodiment of the disclosure, the reserved space is filled with a material with resistivity lower than that of the substrate.

According to an embodiment of the present disclosure, the shape of the reserved space includes at least one of a rectangle and other polygons.

According to an embodiment of the present disclosure, the material filled in the reserved space includes silicone grease.

According to an embodiment of the present disclosure, the above semiconductor laser includes a stripe semiconductor laser, a ridge semiconductor laser, and a buried heterostructure semiconductor laser.

According to another embodiment of the present disclosure, there is provided a method of manufacturing a semiconductor laser, including: preparing a substrate including a reserved space; the semiconductor laser is prepared based on the substrate including the headspace.

According to an embodiment of the present disclosure, preparing a substrate including a headspace includes: preparing a mask plate with a predefined shape; and etching the substrate by utilizing a photoetching technology based on the mask plate to obtain the substrate comprising the reserved space.

According to an embodiment of the present disclosure, preparing a substrate including a headspace includes: and etching the substrate by using a plasma etching technology to obtain the substrate comprising the reserved space.

According to an embodiment of the present disclosure, fabricating the semiconductor laser based on the substrate including the headspace includes: and growing an N electrode, an N-type lower limiting layer, an N-type lower waveguide layer, an active region, a P-type upper waveguide layer, a P-type upper limiting layer and a P electrode on the basis of the substrate comprising the reserved space to obtain the semiconductor laser.

According to the technical scheme, the embodiment of the disclosure has at least the following beneficial effects:

through the substrate hollowing technology, a reserved space is arranged on the substrate layer below the active area, so that parasitic capacitance is reduced, high-frequency loss is reduced, and the effect of improving the bandwidth of the directly modulated semiconductor laser is achieved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 schematically shows a schematic structural view of a semiconductor laser based on a substrate hollowing technique.

Fig. 2 schematically shows a schematic representation of a substrate headspace.

Description of reference numerals:

1. the N-type waveguide layer comprises an N electrode, a 2N-type substrate, a 3N-type lower limiting layer and a 4N-type lower waveguide layer; 5. an active region, 6, a P-type upper waveguide layer, 7, a P-type upper limiting layer, 8, a P electrode; 9. and reserving space.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is illustrative only and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure.

In the related art, the bandwidth of the directly modulated laser is improved mostly by the growth of the semiconductor material and the matching of the later electrode, and the bandwidth is difficult to be improved. In view of the above, embodiments of the present disclosure provide a semiconductor laser based on a substrate hollowing technique.

As shown in fig. 1, an embodiment of the present disclosure includes: a semiconductor laser comprises an N electrode 1, an N-type substrate 2, an N-type lower limiting layer 3, an N-type lower waveguide layer 4, an active region 5, a P-type upper waveguide layer 6, a P-type upper limiting layer 7 and a P electrode 8 which are sequentially grown from bottom to top; wherein the N-type substrate comprises a headspace 9.

As shown in fig. 1, the placement order of the embodiments of the present disclosure is positive.

According to an embodiment of the present disclosure, the headspace 9 in the state of being placed is disposed directly below the active region.

According to the embodiment of the disclosure, the reserved space is arranged on the substrate layer below the active region, so that the parasitic capacitance is reduced, the high-frequency loss is reduced, and the effect of improving the bandwidth of the directly modulated semiconductor laser is achieved.

Fig. 2 schematically shows a schematic representation of the head space 9.

As shown in fig. 2, the shape of the headspace 9 of the embodiment of the present disclosure may be at least one of a rectangle or other polygon.

According to the embodiment of the disclosure, the size of the reserved space 9 can be optimized for different kinds of lasers to obtain the optimal matching resistance and capacitance parameters.

According to the embodiment of the disclosure, when the shape of the reserved space 9 is rectangular, the optimal matching resistance and capacitance parameters can be obtained with the bar-shaped laser.

According to an embodiment of the present disclosure, the headspace 9 may be filled with a material having a lower resistivity than the substrate.

According to the embodiment of the disclosure, the material with lower resistivity than the N-type substrate 2 is filled in the reserved space 9, so that lower capacitance and better heat dissipation effect can be obtained.

According to an embodiment of the present disclosure, the material filled in the headspace 9 may be silicone grease.

According to an embodiment of the present disclosure, the semiconductor laser includes a stripe semiconductor laser, a ridge semiconductor laser, and a buried heterostructure semiconductor laser.

According to an embodiment of the present disclosure, there is also provided a method of manufacturing a semiconductor laser, including: preparing a substrate including a reserved space; the semiconductor laser is prepared based on the substrate including the headspace.

According to the embodiment of the disclosure, the field of view of each exposure can be increased by using the photoetching technology, the compensation of the unevenness of the surface of the substrate silicon wafer is provided, and the size uniformity of the whole silicon wafer is improved.

According to the embodiment of the disclosure, the plasma etching has the advantages of high etching rate, good uniformity and selectivity, avoidance of waste liquid and waste material pollution and the like.

According to the embodiment of the disclosure, the semiconductor laser with a traditional structure is used, the existing semiconductor laser process is combined, the overall parasitic capacitance of the semiconductor laser can be reduced through the substrate reserved space 9, the loss of microwave signals caused by high material resistivity is reduced, the bypass capacitance is improved while the electromagnetic wave leakage of the substrate can be reduced by arranging the reserved space 9, the modulation bandwidth is increased, the high-speed direct modulation of the semiconductor laser is realized, and the low-cost information transmission with higher speed is achieved.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A semiconductor laser comprises an N electrode, an N-type substrate, an N-type lower limiting layer, an N-type lower waveguide layer, an active region, a P-type upper waveguide layer, a P-type upper limiting layer and a P electrode which are sequentially grown from bottom to top; wherein the N-type substrate includes a reserved space.

2. The laser of claim 1, wherein the headspace is disposed directly below the active region.

3. The laser of claim 1, wherein the headspace is filled with a material having a lower resistivity than the substrate.

4. The laser of claim 1, wherein the shape of the headspace comprises at least one of a rectangle and other polygon.

5. The laser according to claim 1, wherein the semiconductor lasers comprise stripe, ridge and buried heterostructure semiconductor lasers.

6. The laser of claim 3, wherein the material filled in the headspace comprises silicone grease.

7. A method of fabricating a semiconductor laser, comprising:

preparing a substrate including a reserved space;

the semiconductor laser is prepared based on the substrate including the headspace.

8. The method of claim 7, wherein preparing the substrate comprising the headspace comprises:

preparing a mask plate with a predefined shape;

and etching the substrate by utilizing a photoetching technology based on the mask plate to obtain the substrate comprising the reserved space.

9. The method of claim 7, wherein preparing the substrate comprising the headspace comprises:

and etching the substrate by using a plasma etching technology to obtain the substrate comprising the reserved space.

10. The method of claim 7, wherein fabricating the semiconductor laser based on the substrate including the headspace includes:

and growing an N electrode, an N-type lower limiting layer, an N-type lower waveguide layer, an active region, a P-type upper waveguide layer, a P-type upper limiting layer and a P electrode on the basis of the substrate comprising the reserved space to obtain the semiconductor laser.