Dual-wavelength monolithic integrated surface emitting semiconductor laser
阅读说明:本技术 一种双波长单片集成面发射半导体激光器 (Dual-wavelength monolithic integrated surface emitting semiconductor laser ) 是由 曾丽娜 李林 李再金 李功捷 乔忠良 赵志斌 刘国军 曲轶 彭鸿雁 于 2020-06-28 设计创作,主要内容包括:本发明公开了一种双波长单片集成面发射半导体激光器,包括蓝宝石衬底,所述蓝宝石衬底顶端自下而上依次生长有缓冲层,第一底部DBR层,第一下势垒层,第一有源层,隧道结层,电流注入层,第一上势垒层,第一顶部DBR层,欧姆接触层,第二底部DBR层,第二下势垒层,第二有源层,第二上势垒层,第二顶部DBR层,盖层,第三底部DBR层,第三下势垒层,第三有源层,第三上势垒层,第三顶部DBR层,窗口层。本发明不仅能够获得高质量的高反射率腔镜,还能有效减小谐振腔的腔长,有利于芯片集成。(The invention discloses a dual-wavelength monolithic integrated surface emitting semiconductor laser, which comprises a sapphire substrate, wherein a buffer layer, a first bottom DBR layer, a first lower barrier layer, a first active layer, a tunnel junction layer, a current injection layer, a first upper barrier layer, a first top DBR layer, an ohmic contact layer, a second bottom DBR layer, a second lower barrier layer, a second active layer, a second upper barrier layer, a second top DBR layer, a cover layer, a third bottom DBR layer, a third lower barrier layer, a third active layer, a third upper barrier layer, a third top DBR layer and a window layer are sequentially grown at the top end of the sapphire substrate from bottom to top. The invention can obtain a high-quality high-reflectivity cavity mirror, can effectively reduce the cavity length of the resonant cavity and is beneficial to chip integration.)
1. A dual wavelength monolithically integrated surface emitting semiconductor laser comprising: the sapphire substrate, the sapphire substrate top grows gradually from bottom to top has the buffer layer, first bottom DBR layer, the first barrier layer that descends, the first active layer, the tunnel junction layer, the current injection layer, the first barrier layer that goes up, first top DBR layer, ohmic contact layer, the second bottom DBR layer, the barrier layer under the second, the second active layer, the barrier layer is gone up to the second, second top DBR layer, the cap layer, third bottom DBR layer, the third barrier layer down, the third active layer, the barrier layer is gone up to the third, third top DBR layer, the window layer.
2. The dual-wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein the semiconductor laser is subjected to a first ICP etching to form a first lithography ICP etching channel, said first lithography ICP etching channel extending from said tunnel junction layer to said window layer.
3. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 2 wherein semiconductor laser is subjected to a second ICP etch to form a second lithographic, ICP etched channel extending from the first bottom DBR layer to the window layer.
4. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein said first bottom DBR layer is epitaxially grown n-type n-GaN/n with different doping concentrations+-GaN DBR homojunction material, n-GaN and n+20 pairs of GaN with the thickness of 35nm and 50nm respectively and the doping concentration of n-GaN of n-1E 18/cm3,n+GaN doping concentration n-1E 19/cm3。
5. According to claim 1The double-wavelength monolithic integrated surface-emitting semiconductor laser is characterized in that the tunnel junction layer is heavily doped n+-GaN/p+-GaN,n+-GaN and p+Doping concentration of GaN was 5E19/cm3The thicknesses were 15nm and 10nm, respectively.
6. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein the first top DBR layer is epitaxially grown n-GaN/n of n-type with different doping concentrations+-GaN DBR homojunction material, n-GaN and n+-15 total pairs of GaN dbr with thicknesses of 35nm and 50nm, respectively, and n-GaN doping concentration of n-1E 18/cm3,n+GaN doping concentration n-1E 19/cm3。
7. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein the second bottom DBR layer is epitaxially grown n-type n-GaN/n with different doping concentrations+-GaN DBR homojunction material, n-GaN and n+-20 total pairs of GaN with a thickness of 40nm and 55nm, respectively, and a n-GaN doping concentration of n-1E 18/cm3,n+GaN doping concentration n-1E 19/cm3。
8. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein the second top DBR layer is epitaxially grown n-GaN/n of n-type with different doping concentrations+-GaN DBR homojunction material, n-GaN and n+-15 pairs of GaN with a thickness of 40nm and 55nm, respectively, and a n-GaN doping concentration of n-1E 18/cm3,n+GaN doping concentration n-1E 19/cm3。
9. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein the third bottom DBR layer is epitaxially grown n-type n-GaN/n with different doping concentrations+-GaN DBR homojunction material, n-GaN and n+-20 pairs of GaN with a thickness of 50nm and 70nm, respectively, and a n-GaN doping concentration of n-1E 18/cm3,n+GaN doping concentration n-1E 19/cm3。
10. A dual wavelength monolithically integrated surface emitting semiconductor laser as claimed in claim 1 wherein the third top DBR layer is epitaxially grown n-type n-GaN/n with different doping concentrations+-GaN DBR homojunction material, n-GaN and n+-15 pairs of GaN with a thickness of 50nm and 70nm, respectively, and a n-GaN doping concentration of n-1E 18/cm3,n+GaN doping concentration n-1E 19/cm3。
Technical Field
The invention belongs to the technical field of semiconductor photoelectron, and particularly relates to a dual-wavelength monolithic integrated surface emitting semiconductor laser.
Background
In recent years, GaN-based semiconductor materials have made great technological breakthrough in epitaxial growth and optoelectronic device fabrication, in which Light Emitting Diodes (LEDs) and Edge Emitting Lasers (EELs) have been industrialized. The blue-green light dual-wavelength monolithic integrated surface-emitting semiconductor laser has wide application prospect in the fields of high-density optical storage, laser display, laser printing, laser illumination, laser television, underwater communication, ocean resource detection, laser biomedicine and the like.
A surface-emitting semiconductor laser resonator is generally composed of a high-reflectivity Distributed Bragg Reflector (DBR). However, for GaN-based semiconductor lasers, it is very difficult to epitaxially grow a DBR, and a high-reflectivity resonant cavity is generally obtained from a multilayer dielectric film DBR. Because the dielectric film is not conductive, the conventional ITO film inner cavity electrode is adopted by the front-emitting semiconductor laser, and the loss caused by absorption of the ITO film inner cavity electrode and the loss caused by an ITO/GaN interface result in higher threshold current and lower light output. The dual-wavelength monolithic integrated surface emitting semiconductor laser utilizes the bonding technology to bond two laser chips with different emitting wavelengths together, and the integration level is lower. The output characteristics of the dual-wavelength laser are affected by bonding temperature, pressure, bonding agent and other factors, so that stable laser output characteristics are not easy to obtain, and chip integration is not facilitated.
Therefore, how to provide a dual-wavelength monolithically integrated surface emitting semiconductor laser is a problem that needs to be solved by those skilled in the art.
Disclosure of Invention
In view of this, the invention provides a dual-wavelength monolithic integrated surface emitting semiconductor laser, which not only can obtain a high-quality high-reflectivity cavity mirror, but also can effectively reduce the cavity length of a resonant cavity, and is beneficial to chip integration.
In order to achieve the purpose, the invention adopts the following technical scheme:
a dual wavelength monolithically integrated surface emitting semiconductor laser comprising: the sapphire substrate, the sapphire substrate top grows gradually from bottom to top has the buffer layer, first bottom DBR layer, the first barrier layer that descends, the first active layer, the tunnel junction layer, the current injection layer, the first barrier layer that goes up, first top DBR layer, ohmic contact layer, the second bottom DBR layer, the barrier layer under the second, the second active layer, the barrier layer is gone up to the second, second top DBR layer, the cap layer, third bottom DBR layer, the third barrier layer down, the third active layer, the barrier layer is gone up to the third, third top DBR layer, the window layer.
Preferably, the semiconductor laser forms a first photoetching and ICP etching channel through first ICP etching, and the first photoetching and ICP etching channel extends from the tunnel junction layer to the window layer.
Preferably, the semiconductor laser forms a second lithography and ICP etching channel by a second ICP etching, the second lithography and ICP etching channel extending from the first bottom DBR layer to the window layer.
Preferably, the first bottom DBR layer is formed by epitaxially growing n-type n-GaN/n with different doping concentrations+-GaN DBR homojunction material, n-GaN and
Preferably, the tunnel junction layer is heavily doped n+-GaN/p+-GaN,n+-GaN and p+Doping concentration of GaN was 5E19/cm3The thicknesses were 15nm and 10nm, respectively.
Preferably, the first top DBR layer is formed by epitaxially growing n-type n-GaN/n with different doping concentrations+-GaNDBR homojunction material, n-GaN and
Preferably, the second bottom DBR layer is formed by epitaxially growing n-type n-GaN/n with different doping concentrations+-GaNDBR homojunction material, n-GaN and n+-20 total pairs of GaN with a thickness of 40nm and 55nm, respectively, and a n-GaN doping concentration of n-
Preferably, the second top DBR layer is formed by epitaxially growing n-type n-GaN/n with different doping concentrations+-GaNDBR homojunction material, n-GaN and n+-15 pairs of GaN with a thickness of 40nm and 55nm, respectively, and a n-GaN doping concentration of n-
Preferably, the third bottom DBR layer is formed by epitaxially growing n-type n-GaN/n with different doping concentrations+-GaNDBR homojunction material, n-GaN and n+-20 pairs of GaN with a thickness of 50nm and 70nm, respectively, and a n-GaN doping concentration of n-
Preferably, the third top DBR layer is formed by epitaxially growing n-type n-GaN/n with different doping concentrations+-GaNDBR homojunction material, n-GaN and n+-15 pairs of GaN with a thickness of 50nm and 70nm, respectively, and a n-GaN doping concentration of n-
The invention has the beneficial effects that:
the invention has compact structure, is a surface emitting semiconductor laser structure for epitaxial growth of near ultraviolet to blue-green light wavelength, forms a near ultraviolet laser pumping blue-green dual-wavelength monolithic integrated surface emitting semiconductor laser, and all semiconductor laser structures are directly obtained by epitaxial growth, thereby solving the difficulty of epitaxial growth of DBR and realizing that three active layers with different light emitting wavelengths and a plurality of pairs of DBR layers can be completed by one-time epitaxial growth. The dual-wavelength monolithic integrated surface emitting semiconductor laser can obtain a high-quality high-reflectivity cavity mirror, effectively reduce the cavity length of a resonant cavity and is beneficial to chip integration.
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, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic diagram of the present invention.
FIG. 2 is a schematic structural diagram of a dual-wavelength monolithic integrated surface emitting semiconductor laser after two times of ICP etching.
Wherein, in the figure,
1 is a sapphire substrate, 2 is a buffer layer, 3 is a first bottom DBR layer, 4 is a first lower barrier layer, 5 is a first active layer, 6 is a tunnel junction layer, 7 is a current injection layer, 8 is a first upper barrier layer, 9 is a first top DBR layer, 10 is an ohmic contact layer, 11 is a second bottom DBR layer, 12 is a second lower barrier layer, 13 is a second active layer, 14 is a second upper barrier layer, 15 is a second top DBR layer, 16 is a cap layer, 17 is a third bottom DBR layer, 18 is a third lower barrier layer, 19 is a third active layer, 20 is a third upper barrier layer, 21 is a third top DBR layer, 22 is a window layer, 30 is a first bottom etched region, 31 is a tunnel junction etched region, 32 is a current injection aperture region, 33 is a first top DBR etched region, 34 is a second bottom DBR region, 35 is a second top etched region, 36 is a third bottom etched region, 37 is a third top DBR region, 40 is a first photoetching and ICP etching channel, and 41 is a second photoetching and ICP etching channel.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1-2, the present invention provides a dual-wavelength monolithic integrated surface emitting semiconductor laser, comprising: the sapphire substrate comprises a
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The invention provides a method for manufacturing a DBR (distributed Bragg Reflector) and a current injection aperture of a double-wavelength monolithic integrated surface-emitting semiconductor laser, which comprises the following specific steps of: firstly, by utilizing MOCVD epitaxial growth equipment, each layer of material is epitaxially grown on a substrate layer from bottom to top, and the primary epitaxial growth is completed from the epitaxial
And secondly, forming a first photoetching and
Then, the semiconductor laser is subjected to a second ICP etching to form a second photo-etched, ICP-etched
Wherein the ICP etching gas is SF6/BCl3The mixed gas (the gas volume ratio is 2:3) has the etching rate of 10nm/min, and can obtain the controllable etching rate. Etching mask material of SiO2Or Si3N4And SiO2Mask Material Using Si3N4The masking material achieves a more vertical and smooth etched sidewall.
The invention realizes the current injection aperture manufacture of the near ultraviolet surface emitting laser epitaxial wafer after the first photoetching and ICP dry etching process, and completes the blue-green light dual-wavelength monolithic integration vertical cavity surface emitting laser preparation process after the second photoetching and ICP dry etching process.
The invention provides a method for manufacturing a dual-wavelength monolithic integrated surface-emitting semiconductor laser electrode, which utilizes the electrode manufacturing process of a conventional semiconductor laser chip, and chip electrodes are respectively manufactured on an ohmic contact layer and a buffer layer.
The invention provides electric pumping laser by the first active region to generate near ultraviolet laser, injects current into the first active region to generate electric injection excited near ultraviolet laser, and pumps the second active region and the third active region by taking the near ultraviolet laser as a pumping source, thereby obtaining blue-green light dual-wavelength laser on a single chip.
The invention provides a dual-wavelength monolithic integration surface emitting semiconductor laser structure, which realizes a high-reflectivity surface emitting laser resonant cavity by epitaxial growth homojunction DBR without a high-reflectivity resonant cavity coating process, thereby ensuring to obtain high-quality cavity mirror materials and solving the problems of cavity mirror complex mode system design and high-reflectivity film and anti-reflection film preparation.
The invention has compact structure, is a surface emitting semiconductor laser structure for epitaxial growth of near ultraviolet to blue-green light wavelength, forms a near ultraviolet laser pumping blue-green dual-wavelength monolithic integrated surface emitting semiconductor laser, and all semiconductor laser structures are directly obtained by epitaxial growth, thereby solving the difficulty of epitaxial growth of DBR and realizing that three active layers with different light emitting wavelengths and a plurality of pairs of DBR layers can be completed by one-time epitaxial growth. The dual-wavelength monolithic integrated surface emitting semiconductor laser can obtain a high-quality high-reflectivity cavity mirror, effectively reduce the cavity length of a resonant cavity and is beneficial to chip integration. The invention adopts a near-ultraviolet wavelength surface-emitting semiconductor laser as a pumping light source to obtain a near-ultraviolet single-chip laser integrated pumping source, thereby realizing blue-green light dual-wavelength monolithic integrated surface-emitting semiconductor laser.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.