JP2010165723A - Method of manufacturing surface emitting laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a surface emitting laser capable of accurately measuring and controlling PL peak wavelength of an active layer of the surface emitting laser. <P>SOLUTION: The method of manufacturing the surface emitting laser includes: a first step of forming a first calibration structure containing, on a substrate 1, a multilayer film reflecting mirror 11 and a resonator 12 which is stacked on the mutilayer film reflecting mirror 11 and has resonator length of (2n+1)λ/4(n is natural number and λ is wavelength); a second step of acquiring an emission peak wavelength from photoluminescence measurement of an active layer 5 in the first calibration structure; a third step of adjusting formation condition of the active layer 5 so that the emission peak wavelength of the active layer 5 comes to be a predetermined wavelength; and a fourth step of forming a surface emitting laser having a resonator containing the active layer and a multilayer film reflecting mirror provided above and below the resonator, based on the formation condition of the active layer 5 available through the third step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a surface emitting laser, and more particularly to a method for manufacturing a surface emitting laser capable of precisely controlling the wavelength.

  Surface emitting lasers (vertical cavity surface emitting lasers: VCSELs) are widely used as light sources for data communication such as public networks and fiber channels because of low cost and low power consumption. An important design parameter that affects the device characteristics of a surface emitting laser is the difference between the oscillation wavelength of the surface emitting laser and the gain peak wavelength of the active layer.

The oscillation wavelength of the surface emitting laser is a resonance peak wavelength determined by a resonator and upper and lower multilayer mirrors (DBR) sandwiching the resonator. On the other hand, the gain peak wavelength of the active layer is a wavelength at which the net gain becomes maximum when carriers are injected into the active layer by current or photoexcitation.
If the resonance peak wavelength and the gain peak wavelength coincide with each other, the oscillation threshold value becomes small and good characteristics are obtained. However, when the gain peak wavelength becomes longer than the resonance peak wavelength due to an increase in the environmental temperature, characteristics such as the oscillation threshold and the optical output rapidly decrease.

  Therefore, if the gain peak wavelength is set in advance on the shorter wavelength side than the resonance peak wavelength, even if the environmental temperature rises by several tens of degrees, the difference between the gain peak wavelength and the resonance peak wavelength changes so as to reduce. Will not drop. Thus, the difference between the resonance peak wavelength and the gain peak wavelength can be said to be an important design parameter that affects the device characteristics. In order to control this wavelength, device fabrication accuracy of several nanometers (nm) is required, and unless this is precisely controlled, the yield of the elements is reduced.

  The resonance peak wavelength can be obtained by measuring the light reflection spectrum of the epitaxial wafer of the surface emitting laser. In the light reflection spectrum of the VCSEL structure, a high DBR reflectance band called a stop bandwidth is measured. Then, a dip due to resonance (a portion where the reflectivity is slightly reduced) is measured at the substantially central portion of the high reflectivity band, and the tip of the dip becomes the resonance peak wavelength.

On the other hand, the gain peak wavelength is a wavelength at which the net gain is maximized when high-density carriers are generated in the active layer by current or photoexcitation, so that it is difficult to measure in the state of the VCSEL wafer. Therefore, it is usual to use the peak wavelength of the photoluminescence (PL) spectrum of the active layer, which has a strong correlation with the gain peak wavelength, as a guide.
Therefore, in the specification of the VCSEL wafer, it is usual to specify the resonance peak wavelength and the PL peak wavelength of the active layer.

  When the PL spectrum of the active layer fabricated in the VCSEL structure is measured through the DBR layer, the peak wavelength of the PL spectrum becomes the same as the resonance peak wavelength due to the influence of the resonator structure. That is, only the wavelength that resonates with the resonance wavelength of the resonator structure comes out through the DBR layer, and the PL peak wavelength inherent in the active layer cannot be measured.

  Therefore, in Patent Document 1, in order to measure the PL peak wavelength inherent in the active layer, only the active layer structure without the DBR structure is formed, and the PL peak of the structure is measured. The growth conditions are adjusted so that the PL peak wavelength of the active layer becomes a predetermined PL peak wavelength. In Patent Document 1, the PL peak wavelength in the VCSEL structure is controlled by laminating the active layer in the VCSEL structure using this growth condition.

JP 2002-289968 A

  However, the method for manufacturing a surface emitting laser according to the background art has the following problems. Even if the growth conditions of the active layer are the same, there is no guarantee that the PL peak wavelength of the active layer in the VCSEL structure is the same as the PL peak wavelength of the active layer structure alone. In fact, in the InGaAs active layer on the GaAs substrate, even if the growth conditions are the same, the PL peak wavelength of the active layer in the VCSEL structure may differ from the PL peak wavelength in the case of only the active layer structure by about 30 nm. The inventors have found that.

Several wafers having only the active layer structure were prepared, and the PL peak wavelength was examined. The reproducibility was very good. Therefore, it is surmised that the difference in the PL peak wavelength is not a problem of the reproducibility of the device but a structural problem due to the active layer being sandwiched between the DBRs.
Specifically, in the VCSEL structure, an active layer is continuously stacked on the lower DBR. At that time, the surface temperature of the substrate differs from the case of only the active layer structure due to the warpage of the substrate due to the influence of the underlying DBR, the change in thermal emissivity, and the like. In particular, those that are sensitive to the growth temperature, such as the In composition, vary greatly due to the influence of the substrate.

In addition, during the growth of the upper DBR, the interface of the quantum well may drift due to the thermal annealing effect, and the PL peak wavelength may shift to the short wavelength side.
Thus, the PL peak wavelength of the active layer in the VCSEL structure may be different from the PL peak wavelength in the case of only the active layer structure, and it is difficult to precisely control the PL peak wavelength of the active layer in the VCSEL structure. It becomes.

Further, as described in the background art, even if an attempt is made to measure the PL peak wavelength of the active layer in the VCSEL structure from the substrate surface through the DBR layer, the PL peak wavelength inherent in the active layer is affected by the resonator structure. Can not be measured.
Therefore, in principle, a cross-sectional micro-PL that cleaves a VCSEL structure wafer and directly measures the PL emission of the active layer from the cross-section of the layer structure is also possible. However, since the active layer is directly exposed to air, surface oxidation occurs, and in a material system having a large surface non-radiative recombination, PL light becomes weak and it is difficult to observe the spectrum.

  Thus, the PL peak wavelength of the active layer in the VCSEL structure is not necessarily the same as the PL peak wavelength in the case of only the active layer structure. In addition, it is difficult to measure the PL peak wavelength in an actual VCSEL structure, and there is a problem that checking at the wafer level cannot be performed. For this reason, unless the VCSEL structure is actually fabricated and the characteristics of the element are measured, the difference between the PL peak wavelength and the resonance peak wavelength of the active layer cannot be determined, so that the yield of the element decreases.

  Accordingly, an object of the present invention is to provide a method for manufacturing a surface emitting laser capable of precisely measuring the PL peak wavelength of an active layer of a surface emitting laser and precisely controlling the PL peak wavelength.

  A surface emitting laser manufacturing method according to the present invention includes a multilayer reflector on a substrate and a (2n + 1) λ / 4 (n is a natural number, λ is a wavelength) resonator laminated on the multilayer reflector. A first step of forming a first calibration structure having a resonator having a length; a second step of determining an emission peak wavelength from a photoluminescence measurement of an active layer in the first calibration structure; Based on the third step of adjusting the formation conditions of the active layer so that the emission peak wavelength of the active layer becomes a predetermined wavelength, and based on the formation conditions of the active layer obtained in the third step, And a fourth step of forming a surface emitting laser having a resonator including a layer and multilayer reflectors provided above and below the resonator.

  With the method for manufacturing a surface emitting laser according to the present invention, a method for manufacturing a surface emitting laser capable of precisely measuring and controlling the PL peak wavelength of the active layer of the surface emitting laser can be provided.

It is sectional drawing of a calibration structure used for manufacture of a surface emitting laser. It is a reflection spectrum of a 3λ / 4 resonator (solid line) and a λ resonator (dashed line). It is a figure for demonstrating the manufacturing method of the surface emitting laser concerning embodiment. 6 is a diagram for explaining a method of manufacturing the surface emitting laser according to Example 1. FIG. 2 shows a PL spectrum (dashed line) of a calibration structure having a 3λ / 4 resonator according to Example 1 and a PL spectrum of a VCSEL structure having a λ resonator. 6 is a diagram for explaining a method of manufacturing the surface emitting laser according to Example 2. FIG.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a calibration structure (first calibration structure) used for manufacturing the surface emitting laser according to the present embodiment. A lower multilayer reflector (DBR) 11 is stacked on the substrate 1, and a resonator 12 having a (2n + 1) λ / 4 resonator length is stacked thereon. The lower DBR 11 is an alternating multilayer film in which a pair of a low refractive index layer 2 having a λ / 4 layer thickness and a high refractive index layer 3 having a λ / 4 layer thickness is formed as a pair, and the uppermost portion is constituted by a low refractive index layer. Has been. The (2n + 1) λ / 4 resonator 12 includes a lower spacer layer 4 and an upper spacer layer 6 sandwiching the active layer portion 5, and the total layer thickness is (2n + 1) λ / 4.

  The reflection spectrum when n is 1 (3λ / 4 resonator) in this calibration structure is shown by the solid line in FIG. In FIG. 2, a region with high reflectivity (about 1010 nm to 1090 nm) is called a stop band, and reflects the reflection characteristics of the lower DBR. In the calibration structure in this case, since the resonator length is set to 3λ / 4, no dip due to resonance is observed in this stop band.

  On the other hand, when the resonator length is λ as used in a normal VCSEL, a dip 7 due to resonance appears in the stop band as shown by the broken line in FIG. This dip 7 is caused by interference between the lower DBR and the resonator section. That is, the dip is not seen in the calibration structure of the 3λ / 4 resonator length because the 3λ / 4 resonator length is a special length that does not cause this interference.

  For example, when the resonator length is slightly shorter than λ, the resonance dip appears on the shorter wavelength side than the λ resonator dip. The resonator length at which the dip disappears completely is 3λ / 4. Thus, a special resonator length that does not cause interference between the lower DBR and the resonator occurs when n is a natural number (2n + 1) λ / 4.

  The absence of interference of the lower DBR in the reflection spectrum is indispensable for measuring the intrinsic PL peak wavelength of the active layer from the wafer surface. This is because if there is interference, light emission at the dip wavelength is strengthened and has a peak at a wavelength different from the original PL peak wavelength of the active layer. Therefore, when PL measurement is performed from the surface side using a calibration structure having a resonator having a (2n + 1) λ / 4 resonator length, the original PL peak wavelength of the active layer without interference of the lower DBR can be measured. It becomes possible.

In addition, since the active layer of this calibration structure is stacked on the lower DBR having the same structure as the real VCSEL structure, it is possible to monitor the shift of the PL peak wavelength caused by the lower DBR as described above. It becomes.
Furthermore, if necessary, the calibration structure is thermally annealed at the same temperature and time as when the upper DBR is stacked, so that the PL peak wavelength can be shortened due to the thermal annealing effect generated when the upper DBR is stacked. The shift amount of the PL wavelength can be measured.
Further, in the VCSEL structure, since the upper DBR is actually laminated, the warpage is slightly larger than in the calibration structure, but the degree of the warpage tends to be saturated, so the calibration structure already warped by the lower DBR lamination is sufficient. The effect of warpage is taken into account.

  As described above, the calibration structure having the lower multilayer reflector and the resonator having the resonator length of (2n + 1) λ / 4 (n is a natural number) including the active layer laminated thereon is used. Thus, it is possible to measure the original emission peak wavelength of the same active layer as the VCSEL structure. Then, by adjusting the formation conditions of the active layer using this and using the formation conditions of the active layer, the emission peak wavelength of the active layer can be precisely adjusted to the target wavelength.

  Next, a method for manufacturing the surface emitting laser according to the present embodiment will be described with reference to FIG. The manufacturing method of the surface emitting laser according to the present embodiment includes the following steps.

First, in the first step, as shown in FIG. 1, a multilayer reflector 11 and (2n + 1) λ / 4 (n is a natural number, λ) laminated on the multilayer reflector 11 on the substrate 1. Form a calibration structure having a resonator 12 having a wavelength) resonator length.
For example, GaAs can be used for the substrate 1. In addition, for example, a Si-doped Al _0.9 Ga _0.1 As low-refractive index layer 2 and a Si-doped GaAs high-refractive index layer 3 can be used for the multilayer mirror 11.

The resonator 12 includes, for example, an AlGaAs spacer layer 4, a 3QW active layer 5 composed of an In _0.3 Ga _0.7 As quantum well layer (QW) and a GaAs (10 nm) barrier layer, and an AlGaAs spacer layer 6. Can be used. As the growth method, film forming means such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) can be used. In addition, after the calibration structure is formed if necessary, the calibration structure may be thermally annealed at the same temperature and time as when the upper DBR is stacked.

  In the second step, the emission peak wavelength (PL peak wavelength) is determined from the photoluminescence measurement of the active layer in the calibration structure. The gain peak wavelength of the active layer can be obtained based on the emission peak wavelength at this time. That is, when determining the gain peak wavelength of the active layer, the emission peak wavelength can be used as a guide.

  In the third step, the formation conditions of the active layer 5 are adjusted so that the emission peak wavelength of the active layer 5 becomes a predetermined wavelength. That is, the formation condition of the active layer 5 is determined so that the emission peak wavelength of the active layer 5 corresponding to the gain peak wavelength of the active layer 5 becomes a predetermined wavelength.

  In the fourth step, a surface emitting laser is formed using the formation conditions of the active layer 5 for obtaining the predetermined wavelength obtained in the third step. That is, when forming a surface emitting laser, a lower multilayer reflector is formed on a substrate, a resonator including an active layer is formed on the lower multilayer reflector, and an upper multilayer reflector is formed on the resonator. Form. In the fourth step, the formation conditions of the active layer obtained in the third step are used when forming the resonator including the active layer on the lower multilayer reflector.

  Since the PL peak wavelength of the active layer in the actual VCSEL structure can be measured by using the surface emitting laser manufacturing method according to the present embodiment, the PL peak wavelength of the active layer of the surface emitting laser is precisely controlled. It becomes possible. Further, since the actual active layer of the VCSEL can be manufactured as designed, the VCSEL characteristic defects caused by the wafer can be reduced, and the yield can be improved.

A method for manufacturing a surface emitting laser according to Example 1 of the present invention will be described with reference to FIG. Here, a VCSEL having an InGaAs quantum well on a GaAs substrate as an active layer will be described as an example. As the growth method, metal organic chemical vapor deposition (MOCVD) is used, but other growth means such as molecular beam epitaxy (MBE) may be used. The design oscillation wavelength λ of the VCSEL at room temperature is 1050 nm, and the target PL peak wavelength λ _aim of the active layer is about 1030 nm. The calibration structure (first calibration structure) of this embodiment is also the same as the structure shown in FIG. 1, and will be described with reference to FIG.

In the first step, an Al _0.9 Ga _0.1 As low-refractive index layer 2 having a Si-doped λ / (4n _l ) layer thickness and a Si-doped λ / The lower DBR 11 composed of 35.5 pairs (0.5 pair is the uppermost low-refractive index layer) was stacked with the GaAs high-refractive index layer 3 having a (4n _h ) layer thickness as one pair.

Here, n _l and n _h are the refractive indexes of the low refractive index layer and the high refractive index layer, respectively. Between each λ / 4 layer there may be an intermediate layer for reducing electrical resistance. A resonator 12 having a resonator length of 3λ / 4 was continuously stacked on the lower DBR 11.

First, after laminating an AlGaAs spacer layer 4 of about λ / 2, a 3QW active layer 5 composed of an In _0.3 Ga _0.7 As (5 nm) quantum well layer (QW) and a GaAs (10 nm) barrier layer is formed. Laminated. Further, an AlGaAs spacer layer 6 of about λ / 4 is laminated thereon to form a 3λ / 4 resonator 12.

As a result, a calibration structure including the DBR 11 and the resonator 12 having the 3λ / 4 resonator length can be formed.
Thereafter, the calibration structure was subjected to thermal annealing in the growth chamber for the same growth temperature and growth time as the upper p-DBR stacked in the actual VCSEL structure.

In the second step, normal room temperature photoluminescence (PL) measurement is performed on the wafer on which the calibration structure is grown, and the emission peak wavelength (PL peak wavelength) is obtained from the PL spectrum. In this example, the PL peak wavelength was 1017 nm.
On the other hand, when only the active layer was grown under the same growth conditions, the PL peak wavelength was 1039 nm. Therefore, it can be seen that the calibration structure has a wavelength as short as 22 nm.

  In the third step, based on the result, the growth condition of the active layer is adjusted so that the PL peak wavelength of the wafer on which the calibration structure is grown is about 1030 nm. In this example, the active layer growth conditions were obtained such that the peak wavelength was 1028 nm as indicated by the broken line in FIG.

In the fourth step, an actual VCSEL structure was grown using the growth conditions obtained in the third step. An actual VCSEL structure has an Al _0.9 Ga _0.1 As low refractive index layer with a resonator length of λ and an upper DBR of C-doped λ / (4n _l ) layer thickness, and a C-doped λ / (4n _h ) A structure consisting of 23 pairs in which a GaAs high refractive index layer having a layer thickness is paired.

  In order to measure the PL peak wavelength in this VCSEL structure, the room temperature PL spectrum of the active layer was measured by cross-sectional micro-PL. The result is shown by the solid line in FIG. The peak wavelength was 1027 nm, and the difference from the calibration-grown wafer was as small as 1 nm. Thus, by adjusting the growth conditions using the calibration structure wafer, it becomes possible to precisely control the PL peak wavelength of the VCSEL active layer, and to produce a VCSEL element having good characteristics with a high yield. Became possible.

  In this embodiment, an example of InGaAs is given as an active layer of a surface emitting laser, but the same effect can be expected in different wavelength bands using other material systems. In this embodiment, the number of quantum wells in the quantum well structure is set to 3. However, the present invention is not limited to this as long as a gain necessary for oscillation can be obtained. In this embodiment, the VCSEL is formed on the n-type GaAs substrate. However, the p-type substrate may be used to reverse the stacking order.

A method for manufacturing a surface emitting laser according to Example 2 of the present invention will be described with reference to FIG. Here, as in the first embodiment, a VCSEL having an InGaAs quantum well on a GaAs substrate as an active layer will be described as an example. As the growth method, metal organic chemical vapor deposition (MOCVD) is used, but other growth means such as molecular beam epitaxy (MBE) may be used. The design oscillation wavelength λ of the VCSEL at room temperature is 1050 nm, and the target PL peak wavelength λ _aim of the active layer is about 1030 nm. The difference from Example 1 is that a structure (second calibration structure) having only the active layer is formed in the third step, the PL peak wavelength of only the active layer is obtained, and growth is performed using the peak value. The point is to adjust the conditions. This will be specifically described below.

In the first step, an Al _0.9 Ga _0.1 As low-refractive index layer 2 having a Si-doped λ / (4n _l ) layer thickness and a Si-doped λ / The lower DBR 11 composed of 35.5 pairs (0.5 pair is the uppermost low-refractive index layer) was stacked with the GaAs high-refractive index layer 3 having a (4n _h ) layer thickness as one pair.

Here, n _l and n _h are the refractive indexes of the low refractive index layer and the high refractive index layer, respectively. Between each λ / 4 layer there may be an intermediate layer for reducing electrical resistance. A resonator 12 having a resonator length of 3λ / 4 was continuously stacked on the lower DBR 11.

First, after laminating an AlGaAs spacer layer 4 of about λ / 2, a 3QW active layer 5 composed of an In _0.3 Ga _0.7 As (5 nm) quantum well layer (QW) and a GaAs (10 nm) barrier layer is formed. Laminated. Further, an AlGaAs spacer layer 6 of about λ / 4 is laminated thereon to form a 3λ / 4 resonator 12.

  Thus, a first calibration structure having the DBR 11 and the resonator 12 having a 3λ / 4 resonator length can be formed.

In the second step, normal room temperature photoluminescence (PL) measurement was performed on the wafer on which the first calibration structure was grown, and an emission peak wavelength (PL peak wavelength) was obtained from the PL spectrum. In this example, the PL peak wavelength λ _a2 was 1017 nm. Here, a difference Δλ = λ _aim −λ _a2 = 13 nm from the target peak wavelength λ _aim is obtained.

In the third step, a second calibration structure having only active layers stacked under the same growth conditions as the active layer growth conditions of the first step is formed, and the PL peak wavelength λ _a0 ( In this embodiment, 1039 nm) is measured. Then, λ _a3 (λ _a3 = λ _a0 ) having different wavelengths by Δλ (Δλ = λ _aim −λ _a2 ), which is the difference between the emission peak wavelength λ _a2 of the first calibration structure and the target peak wavelength λ _aim + Δλ) is set to the target wavelength of the active layer of the second calibration structure.

That is, in this embodiment, the second calibration structure having only the active layer is used to adjust the growth condition of the active layer in the VCSEL structure. Then, in the second calibration structure, the PL peak wavelength λ _a3 (λ _a3 = λ _a0 + Δλ = 1052 nm) is set as a target value, and the growth conditions of the active layer of the second calibration structure are set so as to be the value. It is adjusted.

  Unlike the first calibration structure, the second calibration structure used in this method is composed of only the active layer portion, so that the growth time can be greatly shortened. That is, with reference to FIG. 1, in Example 3, in the third step of adjusting the formation conditions of the active layer, the formation conditions are obtained by forming the DBR 11 and the resonator 12. However, in Example 2, since the formation conditions of the active layer can be obtained by forming only the active layer 5, the formation conditions can be obtained in a shorter time.

  In this embodiment, an example of InGaAs is given as an active layer of a surface emitting laser, but the same effect can be expected in different wavelength bands using other material systems. In this embodiment, the number of quantum wells in the quantum well structure is set to 3. However, the present invention is not limited to this as long as a gain necessary for oscillation can be obtained. In this embodiment, the VCSEL is formed on the n-type GaAs substrate. However, the p-type substrate may be used to reverse the stacking order.

  The present invention can be widely applied to data communication fields such as public networks and fiber channels, laser beam printers, optical interconnects, and the like where surface emitting lasers are used.

1 Substrate 2 Low Refractive Index Layer 3 High Refractive Index Layer 4 Lower Spacer Layer 5 Active Layer 6 Upper Spacer Layer 7 Dip 11 Lower Multilayer Reflector (DBR)
12 (2n + 1) λ / 4 resonator

Claims (5)

A multilayer reflector on the substrate, and a resonator having a resonator length of (2n + 1) λ / 4 (n is a natural number and λ is a wavelength) laminated on the multilayer reflector. A first step of forming a calibration structure;
A second step of obtaining an emission peak wavelength from photoluminescence measurement of the active layer in the first calibration structure;
A third step of adjusting the formation conditions of the active layer such that the emission peak wavelength of the active layer becomes a predetermined wavelength;
Based on the formation conditions of the active layer obtained in the third step, a fourth surface-emitting laser including a resonator including the active layer and multilayer reflectors provided above and below the resonator is formed. Process,
The manufacturing method of the surface emitting laser which has.   The said 1st process further has the process of heat-processing the said 1st calibration structure on the same conditions as the conditions which form a multilayer film reflective mirror in the upper part of a resonator at the said 4th process. Manufacturing method of the surface emitting laser. The third step includes
Forming a second calibration structure having an active layer formed on a substrate;
The emission peak wavelength λ _a0 is determined from the photoluminescence measurement of the active layer in the second calibration structure,
Λ _{a3 having} a different wavelength by Δλ (Δλ = λ _aim −λ _a2 ), which is the difference between the emission peak wavelength λ _a2 obtained from the photoluminescence measurement of the active layer in the first calibration structure and the predetermined wavelength λ _aim The method for manufacturing a surface emitting laser according to claim 1, wherein the method is a step of adjusting the formation conditions of the active layer of the second calibration structure so that (λ _a3 = λ _a0 + Δλ).   The first step includes a multilayer reflector in which AlGaAs and GaAs are alternately laminated on a GaAs substrate, an AlGaAs lower spacer layer laminated on the multilayer reflector, an InGaAs quantum well layer, 4. The method of manufacturing a surface emitting laser according to claim 1, wherein the first calibration structure includes an active layer having a GaAs barrier layer and an AlGaAs upper spacer layer. The fourth step includes
A lower multilayer reflector is formed on the substrate, a lower spacer layer is formed on the lower multilayer reflector, and the active layer obtained in the third step is formed on the lower spacer layer based on the formation conditions of the active layer. The surface according to any one of claims 1 to 4, which is a step of forming an active layer, forming an upper spacer layer on the active layer, and forming an upper multilayer reflector on the upper spacer layer. Manufacturing method of light emitting laser.

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