CN119209203A - Epitaxial structure of vertical cavity surface emitting laser and its verification method - Google Patents
Epitaxial structure of vertical cavity surface emitting laser and its verification method Download PDFInfo
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- H—ELECTRICITY
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- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
- H01S5/3403—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers having a strained layer structure in which the strain performs a special function, e.g. general strain effects, strain versus polarisation
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- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
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- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
- H01S5/18308—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] having a special structure for lateral current or light confinement
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- H—ELECTRICITY
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- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
- H01S5/18361—Structure of the reflectors, e.g. hybrid mirrors
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- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
- H01S5/343—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser
- H01S5/34313—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs
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Abstract
The invention provides an epitaxial structure of a vertical cavity surface emitting laser and a verification method thereof, wherein the verification method is characterized in that an epitaxial structure of a GaAs substrate of which the mole fraction of Al is more than 60% is adopted as a buffer layer for carrying out epitaxial verification, epitaxial growth of the AlGaAs buffer layer is monitored in situ during the epitaxial verification, so that the frequency of trial production is reduced, the epitaxial verification efficiency is improved, in addition, the AlGaAs buffer layer of which the mole fraction of Al is more than 60% is grown on the GaAs substrate by adopting an epitaxial process, and meanwhile, an AlGaAs material of which the mole fraction of Al is more than 60% is deposited on the inner wall of an epitaxial process chamber in the epitaxial process as an inner wall protection layer, so that defects formed on the surface of an epitaxially grown film layer due to falling of impurity particles in the epitaxial process chamber during epitaxial growth can be reduced or even avoided, and simultaneously, the heat of depositing the inner wall protection layer on the inner wall of the epitaxial process chamber can be removed, and the epitaxial verification efficiency is further improved.
Description
Technical Field
The invention relates to the field of semiconductor lasers, in particular to an epitaxial structure of a vertical cavity surface emitting laser and a verification method thereof.
Background
The resonator of the vertical cavity Surface emitting laser (VCSEL, vertical Cavity Surface EMITTING LASER) is formed by a bragg mirror, which causes the laser light to exit along the material epitaxial direction, i.e., perpendicular to the substrate. The method has the advantages of high beam quality, single longitudinal mode lasing, low threshold current density, on-chip test, easiness in two-dimensional array integration and the like, and is widely applied to the fields of optical interconnection, optical communication, face recognition, laser radar and the like.
In order to improve the quality of the film layer of the epitaxial structure of the vertical cavity surface emitting laser, and further improve the yield of the epitaxial structure of the vertical cavity surface emitting laser, the epitaxial structure needs to be checked, after the epitaxial equipment of the vertical cavity surface emitting laser is subjected to maintenance such as replacement of epitaxial process chamber fittings and the like which affect the growth result, the epitaxial process chamber is baked at a high temperature, and then a material with stronger adhesiveness is deposited on the inner wall in the epitaxial process chamber to serve as an inner wall protection layer, so that defects formed on the surface of the epitaxially grown film layer due to falling of impurity particles are reduced or even avoided, and further the performance of the vertical cavity surface emitting laser is affected. And after depositing the inner wall protective layer, performing trial production of the epitaxial structure of the vertical cavity surface emitting laser, and adjusting corresponding growth parameters according to the trial growth result until the trial production result meets the preset requirement, and performing formal continuous production of the epitaxial structure of the vertical cavity surface emitting laser.
The conventional epitaxial structure of the vertical cavity surface emitting laser in the prior art comprises a GaAs substrate, a GaAs buffer layer, an N-type AlGaAs Bragg reflector layer, an InGaAs quantum well active region layer, an AlGaAs oxidation limiting region layer and a P-type AlGaAs Bragg reflector layer from bottom to top, wherein when the epitaxial structure is used for epitaxial verification, the GaAs buffer layer has no refractive index difference with the GaAs substrate material, and can not obtain growth state change in the first time through an in-situ monitoring means, so that the performance of the epitaxial structure of the vertical cavity surface emitting laser is influenced, the frequency of test production is further increased, and the efficiency of epitaxial verification is influenced.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide an epitaxial structure of a vertical cavity surface emitting laser and a calibration method thereof, which are used for solving the problems that when conventional epitaxial structures in the prior art are used for epitaxial calibration, the performance of the epitaxial structure of the vertical cavity surface emitting laser is affected, the number of times of trial production is increased, and the efficiency of epitaxial calibration is affected due to the need of depositing a protective layer on the inner wall of an epitaxial process chamber and the inability to perform in-situ monitoring on an epitaxially grown GaAs buffer layer.
In order to achieve the above and other related objects, the present invention provides an epitaxial structure of a vertical cavity surface emitting laser, which sequentially comprises, from bottom to top, a GaAs substrate, an AlGaAs buffer layer, an N-type AlGaAs bragg reflector layer, an InGaAs quantum well active region layer, an AlGaAs oxidation restriction layer, and a P-type AlGaAs bragg reflector layer, wherein the material composition of the AlGaAs buffer layer is Al xGa(1-x) As, and 0.6< x <1.
Optionally, the epitaxial structure of the vertical cavity surface emitting laser further comprises a GaAs ohmic contact layer over the P-type AlGaAs bragg reflector layer.
Optionally, the thickness of the AlGaAs buffer layer is 100 nm-1000 nm.
Optionally, the number of quantum wells in the InGaAs quantum well active region layer is 3-6, and the N-type AlGaAs bragg reflector layer is provided with 42 pairs of bragg reflectors.
The invention also provides a verification method of the epitaxial structure of the vertical cavity surface emitting laser, which adopts the epitaxial structure of the vertical cavity surface emitting laser to carry out epitaxial verification, and comprises the following steps:
S1, performing trial production of the epitaxial structure of the vertical cavity surface emitting laser, firstly growing the AlGaAs buffer layer on the GaAs substrate by adopting an epitaxial process, simultaneously depositing an AlGaAs material forming the AlGaAs buffer layer on the inner wall of an epitaxial process chamber in the epitaxial process as an inner wall protection layer, and monitoring trial growth parameters of the AlGaAs buffer layer;
S2, continuing the trial production to continue epitaxial growth of other film layers of the epitaxial structure of the vertical cavity surface emitting laser above the AlGaAs buffer layer, and monitoring trial growth parameters of the other film layers;
s3, judging whether the trial production result meets a preset requirement or not, correspondingly adjusting the trial production parameters according to the trial production result if the trial production result does not meet the preset requirement, and continuing to perform the steps S1, S2 and S3 based on the adjusted production parameters until the trial production result meets the preset requirement;
s4, the test production result reaches the preset requirement, and formal continuous production of the epitaxial structure of the vertical cavity surface emitting laser is carried out.
Optionally, before the production test of the vertical cavity surface emitting laser epitaxial structure, the method further comprises the steps of maintaining equipment of the epitaxial process chamber and baking the epitaxial process chamber.
Optionally, the method for monitoring the growth state of the AlGaAs buffer layer is EpiTT technology in-situ monitoring.
Optionally, the test growth parameters include film thickness, growth rate, molar composition metering, and surface morphology.
Optionally, when performing the formal continuous production of the epitaxial structure of the vertical cavity surface emitting laser, determining whether the result of the formal continuous production meets the preset requirement, and if not, repeating steps S1 to S4.
Optionally, the number of times of trial production is 1-2 times.
The epitaxial structure of the vertical cavity surface emitting laser and the verification method thereof have the advantages that the epitaxial verification is carried out by adopting the epitaxial structure of the vertical cavity surface emitting laser with the mole fraction of Al being more than 60% as the buffer layer, so that the AlGaAs buffer layer is different from a GaAs substrate material, the epitaxial growth of the AlGaAs buffer layer can be monitored in situ during the epitaxial verification, the test growth parameters can be timely adjusted during the epitaxial verification, the test production times are further reduced, the epitaxial verification efficiency is improved, in addition, the AlGaAs buffer layer with the mole fraction of Al being more than 60% is grown on the GaAs substrate by adopting the epitaxial process, and the AlGaAs material with the mole fraction of Al being more than 60% is deposited on the inner wall of the epitaxial process chamber in the epitaxial process as the inner wall protection layer, so that the defect that impurity particles in the epitaxial process chamber drop on the surface of the epitaxially grown film layer is formed during the epitaxial growth is reduced, the performance of the epitaxial structure of the vertical cavity surface emitting laser is further influenced, the inner wall deposition protection layer on the inner wall of the epitaxial process chamber is removed, and the epitaxial verification efficiency is further improved.
Drawings
Fig. 1 is a schematic cross-sectional view showing the epitaxial structure of the vertical cavity surface emitting laser according to the present invention.
Fig. 2 is a flow chart of a verification method of the epitaxial structure of the vertical cavity surface emitting laser of the present invention.
Description of element reference numerals
10 GaAs substrate
11 AlGaAs buffer layer
12 N-type AlGaAs Bragg reflector layer
13 InGaAs quantum well active region layer
14 AlGaAs oxidation confinement layer
15 P-type AlGaAs Bragg reflector layer
16 GaAs ohmic contact layer
S1-S4 step
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
Please refer to fig. 1-2. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings rather than the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.
The embodiment provides an epitaxial structure of a vertical cavity surface emitting laser, as shown in fig. 1, which sequentially comprises a GaAs substrate 10, an AlGaAs buffer layer 11, an N-type AlGaAs Bragg reflector layer 12, an InGaAs quantum well active region layer 13, an AlGaAs oxidation limiting layer 14 and a P-type AlGaAs Bragg reflector layer 15 from bottom to top, wherein the material composition of the AlGaAs buffer layer 11 is Al xGa(1-x) As, and 0.6< x <1.
The epitaxial structure of the vertical cavity surface emitting laser of the embodiment adopts AlGaAs as the buffer layer, so that the epitaxial structure is different from a GaAs substrate material, and in-situ monitoring can be carried out when the AlGaAs buffer layer grows in an epitaxial mode, a high-quality buffer layer film layer is obtained, and further the performance of the epitaxial structure of the vertical cavity surface emitting laser is improved. In addition, the epitaxial structure of the vertical cavity surface emitting laser can be adopted for epitaxial verification, and epitaxial growth of the AlGaAs buffer layer can be monitored in situ during epitaxial verification, so that the test growth parameters can be timely adjusted in the epitaxial process, the test production frequency can be further reduced, the verification efficiency is improved, and the AlGaAs buffer layer with the mole fraction of Al being more than 60% is grown on the GaAs substrate by adopting an epitaxial process, and meanwhile, alGaAs materials with the mole fraction of Al being more than 60% are deposited on the inner wall of the epitaxial process chamber in the epitaxial process as an inner wall protection layer, so that defects formed on the surface of an epitaxially grown film layer due to falling of impurity particles in the epitaxial process chamber during epitaxial growth can be reduced or even avoided, the performance of the epitaxial structure of the vertical cavity surface emitting laser is further influenced, and meanwhile, the heat of depositing an inner wall protection layer on the inner wall of the epitaxial process chamber can be removed, and the verification efficiency is further improved.
The material composition of the AlGaAs buffer layer 11 is Al xGa(1-x) As, wherein 0.6< x <1, that is, the molar fraction of Al is x and the molar fraction of Ga is 1-x in the AlGaAs buffer layer 11, which may be expressed herein As the molar fraction of Al of the AlGaAs buffer layer 11 is greater than 60%.
As an example, the epitaxial structure of the vcsels further includes a GaAs ohmic contact layer 16 located above the P-AlGaAs bragg reflector layer 15, where the thickness of the GaAs ohmic contact layer 16 may be 50 nm-2000 nm, and the GaAs ohmic contact layer 16 may form a top electrode of the vcsels epitaxial structure, so as to drive the vcsels to work, and the GaAs ohmic contact layer 16 not only helps to improve the electrical injection efficiency of the vcsels, but also can reduce the contact resistance, thereby reducing the power loss.
The thickness of the AlGaAs buffer layer 11 may be adjusted according to the performance specification requirement of the target device, for example, the thickness of the AlGaAs buffer layer 11 may be set to 100 nm-1000 nm, so as to reduce the stress caused by lattice constant mismatch of the GaAs substrate 10 and the N-type AlGaAs bragg reflector layer 12 material, and the AlGaAs buffer layer provides a smooth initial surface, which is favorable for the uniform growth of the subsequent epitaxial layer, and maintains the film quality of the epitaxial layer of the N-type AlGaAs bragg reflector layer 12.
The logarithm, the material composition and the light-emitting wavelength of the N-type AlGaAs bragg reflector layer 12 and the P-type AlGaAs bragg reflector layer 15 can be adjusted according to the performance specification requirement of the target device, as a specific example, the N-type AlGaAs bragg reflector layer 12 is an N-type AlGaAs bragg reflector with 42 pairs of material compositions of Al 0.9Ga0.1 As or Al 0.06Ga0.94 As, the bragg center wavelength is 940nm, the P-type AlGaAs bragg reflector layer 15 is a P-type AlGaAs bragg reflector with 20 pairs of material compositions of Al 0.9Ga0.1 As or Al 0.06Ga0.94 As, and the bragg center wavelength is 940nm.
The material composition of the AlGaAs oxidation restriction layer 14 may also be adjusted according to the performance specification requirements of the target device, and As a specific example, the material composition of the AlGaAs oxidation restriction layer 14 is Al 0.98Ga0.02 As.
As an example, the InGaAs quantum well active region layer 13 includes 3 to 6 InGaAs quantum wells, and the InGaAs quantum wells emit light at a wavelength of 920nm at room temperature.
AlGaAs material with the mole fraction of Al being more than 60% is deposited on the inner wall of the epitaxial process chamber as an inner wall protection layer, the AlGaAs material with the higher mole fraction of Al has stronger adhesion capability on impurity particles in the epitaxial process chamber, can be deposited on the inner wall of the epitaxial process chamber in an adhering manner, reduces or even avoids defects formed on the surface of an epitaxially grown film layer due to dropping of the impurity particles, and further influences the performance of the epitaxial structure of the vertical cavity surface emitting laser.
As described in the background art, in the conventional verification method of the vertical cavity surface emitting laser epitaxial structure, before test production, that is, before epitaxially growing a GaAs buffer layer on a GaAs substrate, an inner wall protection layer needs to be deposited on the inner wall of the epitaxial process chamber, so as to reduce or even avoid defects formed on the surface of the epitaxially grown film layer due to dropping of impurity particles. In addition, the GaAs buffer layer has no refractive index difference as the GaAs substrate material, and can not obtain the growth state change in the first time by an in-situ monitoring means, so that the performance of the epitaxial structure of the vertical cavity surface emitting laser is affected, the frequency of trial production is increased, and the epitaxial verification efficiency is affected.
In this embodiment, the process of performing one epitaxial growth is referred to as one heat, and all the heat for performing the whole epitaxial verification process, that is, performing deposition of the inner wall protection layer, performing trial production, and performing formal continuous production, is referred to as one heat, and the whole heat is taken as an example, wherein at least 1 heat is required for depositing the inner wall protection layer, and since the GaAs buffer layer is the same as the GaAs substrate material, there is no refractive index difference, the growth state change cannot be obtained in the first time by the in-situ monitoring means, and at least 2 to 3 heat are required for the trial production, so that at least 3 to 4 heat is required before the formal continuous production, and at least 15 to 20% of the whole heat is required for performing the formal continuous production, thereby affecting the epitaxial verification efficiency.
Based on this, this embodiment also provides a method for verifying an epitaxial structure of a vcsels, as shown in fig. 1 and fig. 2, where the epitaxial verification is performed by using the epitaxial structure of a vcsels according to any one of the above, and the verification method is shown in fig. 2, and includes the following steps:
S1, performing trial production of the epitaxial structure of the vertical cavity surface emitting laser, firstly adopting an epitaxial process to grow the AlGaAs buffer layer 11 on the GaAs substrate 10, simultaneously depositing an AlGaAs material forming the AlGaAs buffer layer 11 on the inner wall of an epitaxial process chamber in the epitaxial process as an inner wall protection layer, and monitoring trial growth parameters of the AlGaAs buffer layer 11;
s2, continuing the trial production to continue epitaxial growth of other film layers of the epitaxial structure of the vertical cavity surface emitting laser above the AlGaAs buffer layer 11, and monitoring trial growth parameters of the other film layers;
s3, judging whether the trial production result meets a preset requirement or not, correspondingly adjusting the trial production parameters according to the trial production result if the trial production result does not meet the preset requirement, and continuing to perform the steps S1, S2 and S3 based on the adjusted production parameters until the trial production result meets the preset requirement;
s4, the test production result reaches the preset requirement, and formal continuous production of the epitaxial structure of the vertical cavity surface emitting laser is carried out.
The verification method of the epitaxial structure of the vertical cavity surface emitting laser of the embodiment adopts the epitaxial structure of the vertical cavity surface emitting laser taking AlGaAs as the buffer layer as the verification structure, so that the AlGaAs buffer layer is different from the GaAs substrate material, therefore, the epitaxial growth of the AlGaAs buffer layer can be monitored in situ during epitaxial verification, the times of trial production are reduced, the verification efficiency is improved, in addition, the AlGaAs buffer layer with the mole fraction of Al larger than 60 percent is grown on the GaAs substrate by adopting an epitaxial process on the GaAs substrate, simultaneously, alGaAs material with mole fraction of Al being more than 60% is deposited on the inner wall of the epitaxial process chamber in the epitaxial process as an inner wall protection layer, so that defects formed by the fact that impurity particles in the epitaxial process chamber fall on the surface of an epitaxially grown film layer during epitaxial growth are reduced or even avoided, the performance of the epitaxial structure of the vertical cavity surface emitting laser is further affected, meanwhile, the furnace number of depositing the inner wall protection layer on the inner wall of the epitaxial process chamber alone can be removed, and the efficiency of epitaxial verification is further improved.
As an example, during the epitaxial verification, before the test production of the epitaxial structure of the vertical cavity surface emitting laser is performed, the method further includes the steps of maintaining the epitaxial equipment of the vertical cavity surface emitting laser by replacing the parts of the epitaxial process chamber and the like according to the growth result, and baking the epitaxial process chamber to remove moisture and other volatile substances in the epitaxial process chamber, thereby reducing or even avoiding the occurrence of film defects in the epitaxial growth process, further affecting the performance of the epitaxial structure of the vertical cavity surface emitting laser, and reducing or even avoiding the oxidation or corrosion of the parts in the epitaxial process chamber.
The rest of the film layers in the step S2 include the N-type AlGaAs bragg mirror layer 12, the InGaAs quantum well active region layer 13, the AlGaAs oxidation restriction layer 14, and the P-type AlGaAs bragg mirror layer 15 in order from bottom to top.
In the verification method, the AlGaAs buffer layer 11 and the rest of film layers need to be monitored for test growth parameters, which include film thickness, growth rate, molar component measurement and surface morphology, as an example, preferably, the method for monitoring the growth state of the AlGaAs buffer layer 11 in this embodiment is EpiTT technology in-situ monitoring, and the EpiTT technology in-situ monitoring can monitor and control the test growth parameters in real time, so as to ensure the stability of the epitaxial growth process and the performance stability of the epitaxial structure of the vertical cavity surface emitting laser.
In step S3, it is required to determine whether the test production result reaches the preset result, where the preset result may be formulated according to the specification of the target vcsels, and the preset result includes, for example, output optical power, threshold current, reflection spectrum wavelength, quantum well wavelength, spectrum width, and/or operation reliability test.
As an example, when the formal continuous production of the epitaxial structure of the vertical cavity surface emitting laser is performed, the method further includes determining whether the result of the formal continuous production meets the preset requirement, and if the result of the formal continuous production does not meet the preset requirement, performing steps S1 to S4 again, that is, performing the epitaxial verification again. As examples, the formal continuous production results include output optical power, threshold current, reflectance spectrum wavelength, quantum well wavelength, spectral width, and/or operational reliability tests, among others.
Taking the whole furnace period of 20 furnace times as an example, wherein the AlGaAs buffer layer 11 is epitaxially grown on the GaAs substrate 10, and simultaneously, the AlGaAs material forming the AlGaAs buffer layer 11 is deposited on the inner wall of the epitaxial process chamber as the inner wall protection layer in the epitaxy process, and the AlGaAs buffer layer 11 can be monitored for test growth parameters in the embodiment, so that the number of test growth is reduced, the test production can be reduced to 1-2 furnace times, namely, 1-2 furnace times are taken before the formal continuous production, which accounts for 5% -10% of the whole furnace period.
In summary, the invention provides an epitaxial structure of a vertical cavity surface emitting laser and a verification method thereof, and the verification method performs epitaxial verification by adopting an epitaxial structure of the vertical cavity surface emitting laser with Al mole fraction larger than 60% as a buffer layer, so that the AlGaAs buffer layer is different from a GaAs substrate material, and therefore, during the epitaxial verification, the epitaxial growth of the AlGaAs buffer layer can be monitored in situ, so that the test growth parameters can be timely adjusted during the epitaxial process, the times of test production can be further reduced, the epitaxial verification efficiency can be improved, in addition, the AlGaAs buffer layer with Al mole fraction larger than 60% is grown on the GaAs substrate by adopting an epitaxial process, and meanwhile, the AlGaAs material with Al mole fraction larger than 60% is deposited on the inner wall of an epitaxial process chamber in the epitaxial process as an inner wall protection layer, thereby reducing or even avoiding the defect that impurity particles in the epitaxial process chamber drop on the surface of the epitaxially grown film layer during the epitaxial growth, further affecting the performance of the vertical cavity surface emitting laser epitaxial structure, and further improving the verification efficiency by removing the furnace times of depositing the inner wall protection layer on the epitaxial process chamber alone. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (10)
1. The epitaxial structure of the vertical cavity surface emitting laser is characterized by sequentially comprising a GaAs substrate, an AlGaAs buffer layer, an N-type AlGaAs Bragg reflector layer, an InGaAs quantum well active region layer, an AlGaAs oxidation limiting layer and a P-type AlGaAs Bragg reflector layer from bottom to top, wherein the material composition of the AlGaAs buffer layer is Al xGa(1-x) As, and the x is 0.6< 1.
2. The epitaxial structure of the vertical cavity surface emitting laser according to claim 1, wherein: the epitaxial structure of the vertical cavity surface emitting laser further comprises a GaAs ohmic contact layer positioned above the P-type AlGaAs Bragg reflector layer.
3. The epitaxial structure of the VCSEL of claim 1 wherein the AlGaAs buffer layer has a thickness of 100 nm-1000 nm.
4. The epitaxial structure of claim 1, wherein the number of quantum wells in the InGaAs quantum well active region layer is 3-6, and the N-type AlGaAs Bragg reflector layer has 42 pairs of Bragg reflectors.
5. A method for verifying an epitaxial structure of a vertical cavity surface emitting laser, characterized in that the epitaxial structure of the vertical cavity surface emitting laser according to any one of claims 1 to 4 is used for performing epitaxial verification, the method comprising the steps of:
S1, performing trial production of the epitaxial structure of the vertical cavity surface emitting laser, firstly growing the AlGaAs buffer layer on the GaAs substrate by adopting an epitaxial process, simultaneously depositing an AlGaAs material forming the AlGaAs buffer layer on the inner wall of an epitaxial process chamber in the epitaxial process as an inner wall protection layer, and monitoring trial growth parameters of the AlGaAs buffer layer;
S2, continuing the trial production to continue epitaxial growth of other film layers of the epitaxial structure of the vertical cavity surface emitting laser above the AlGaAs buffer layer, and monitoring trial growth parameters of the other film layers;
s3, judging whether the trial production result meets a preset requirement or not, correspondingly adjusting the trial production parameters according to the trial production result if the trial production result does not meet the preset requirement, and continuing to perform the steps S1, S2 and S3 based on the adjusted production parameters until the trial production result meets the preset requirement;
s4, the test production result reaches the preset requirement, and formal continuous production of the epitaxial structure of the vertical cavity surface emitting laser is carried out.
6. The method of calibrating a VCSEL epitaxial structure of claim 5 further comprising performing equipment maintenance on the epitaxial process chamber and baking the epitaxial process chamber prior to performing the trial production of the VCSEL epitaxial structure.
7. The method of verifying an epitaxial structure of a VCSEL as set forth in claim 5 wherein the method of monitoring the growth state of the AlGaAs buffer layer is EpiTT in-situ.
8. The method of verifying a VCSEL epitaxial structure of claim 5, wherein the test growth parameters include film thickness, growth rate, molar fraction measurement, and surface morphology.
9. The method of verifying the epitaxial structure of a VCSEL as set forth in claim 5, wherein the step of performing the normal continuous production of the VCSEL epitaxial structure further includes determining whether the normal continuous production result meets the predetermined requirement, and if not, performing steps S1 to S4 again.
10. The method for verifying the epitaxial structure of the VCSEL of claim 5, wherein the number of times of trial production is 1-2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411301648.2A CN119209203A (en) | 2024-09-18 | 2024-09-18 | Epitaxial structure of vertical cavity surface emitting laser and its verification method |
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| KR20210015713A (en) * | 2019-08-02 | 2021-02-10 | 주식회사 레이아이알 | Laser device |
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