JP2009283722A - Surface emitting laser element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable surface emitting laser element wherein the occurrence of dislocation is suppressed even when a DBR (Distributed Bragg Reflector) mirror is formed on a substrate. <P>SOLUTION: In a surface emitting laser element 100, an average distortion of a lower DBR mirror 2 and a film thickness of the lower DBR mirror 2 are so set that warpage of a substrate 1 satisfies a prescribed condition, and nitrogen is added to the lower DBR mirror 2 with a composition, for example, of 0.028 to 0.390% corresponding to the set average distortion of the lower DBR mirror 2 on the basis of the relation between the average distortion of the lower DBR mirror 2 and an average nitrogen composition included in the lower DBR mirror 2, whereby the occurrence of dislocation can be properly suppressed even when the DBR mirror is formed on the substrate 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes a lower multilayer reflector formed of a periodic structure of a high refractive index layer and a low refractive index layer, and an upper multilayer film formed of a periodic structure of a high refractive index layer and a low refractive index layer. The present invention relates to a light emitting laser element provided.

  Vertical cavity surface emitting lasers (VCSELs) are various light sources for optical communication such as optical interconnection or other various application devices. (See, for example, Patent Document 1). Since the surface emitting laser element emits laser light in a direction perpendicular to the substrate, a plurality of elements can be easily two-dimensionally arranged on the same substrate as compared with the conventional edge emitting laser element. Further, since the volume of the active layer is very small, there are many advantages such that laser oscillation is possible with extremely low threshold current and low power consumption. In such a surface emitting laser element, a DBR (Distributed Bragg Reflector) mirror is used as a mirror constituting the resonator.

  Here, when the DBR mirror is laminated on the substrate, there is a problem that dislocation occurs due to lattice mismatch between the substrate and the DBR mirror, and the reliability of the surface emitting laser element is lowered. In order to reduce this dislocation, conventionally, a surface-emitting laser element (see Patent Document 1) that employs a substrate added with In (indium) to reduce the warpage of the substrate and reduce the occurrence of dislocation, or a semiconductor that constitutes a DBR mirror. Surface emitting laser elements (see Patent Document 2 and Patent Document 3) in which nitrogen is added to the material to maintain lattice matching have been proposed.

JP-A-2005-252111 JP-A-10-173295 JP-A-6-37355

  However, the surface emitting laser element described in Patent Document 1 has a problem that it is technically very difficult to uniformly add In to the substrate. In addition, Patent Document 2 and Patent Document 3 have a description of adding nitrogen to a semiconductor material constituting a DBR mirror, but do not specifically show the amount of nitrogen that can appropriately reduce dislocation generation. There is a problem that it is difficult to actually manufacture a surface emitting laser element in which generation is suppressed.

  An object of the present invention is to provide a highly reliable surface emitting laser element that suppresses the occurrence of dislocation even when a DBR mirror is formed on a substrate.

In order to solve the above-described problems and achieve the object, a surface emitting laser element according to the present invention includes a substrate, a lower high-refractive-index layer formed on the substrate and formed of a compound containing Ga and As. A lower multilayer reflector formed of a periodic structure with a lower low refractive index layer formed of a compound containing Al and As, and an upper portion formed of a periodic structure of an upper high refractive index layer and an upper low refractive index layer In the surface emitting laser device comprising: an optical resonator having a multilayer mirror; and an active layer provided between the lower multilayer mirror and the upper multilayer mirror and generating light. The lower multilayer mirror includes nitrogen, the warp of the substrate is C (μm), the average strain of the lower multilayer mirror is S (%), and the thickness of the substrate is d (μm). ) And the diameter of the substrate is D (inch) When the film thickness of the lower multilayer reflector is T (μm), the average strain of the lower multilayer reflector and the film thickness of the lower multilayer reflector are expressed by the following mathematical formula ( 1) is set based on the following formula (2) so as to satisfy 1), and the nitrogen is expressed by the formula (2) in the relationship between the average strain and the average nitrogen composition contained in the lower multilayer mirror. The lower multilayer reflector has a composition corresponding to the average strain S set using

  Here, the average strain is: ((Lattice mismatch degree of the lower high refractive index layer with respect to the substrate × Thickness of the lower high refractive index layer + Lattice mismatch degree of the lower low refractive index layer with respect to the substrate × Lower lower refractive index layer) Thickness)) / (thickness of lower high refractive index layer + thickness of lower low refractive index layer). The average nitrogen composition is ((nitrogen composition ratio of lower high refractive index layer × thickness of lower high refractive index layer + nitrogen composition ratio of low refractive index layer × thickness of lower low refractive index layer)) / ( The thickness of the lower high refractive index layer + the thickness of the lower low refractive index layer). The nitrogen composition ratio refers to the content of an element containing nitrogen among the elements constituting the lower high refractive index layer and the lower low refractive index layer.

Further, in the surface emitting laser element according to the present invention, the relationship between the average strain and the average nitrogen composition contained in the lower multilayer reflector is such that the average nitrogen composition contained in the lower multilayer reflector is N. It is represented by the following mathematical formula (3).

  In the surface emitting laser element according to the present invention, an average nitrogen composition contained in the lower multilayer mirror is 0.028% to 0.390%.

  In the surface emitting laser element according to the present invention, the average nitrogen composition contained in the lower multilayer mirror is 0.072% or more.

  The surface emitting laser element according to the present invention is characterized in that an average nitrogen composition contained in the lower multilayer mirror is 0.263% or more.

A surface-emitting laser device according to the present invention includes a substrate, a lower high refractive index layer formed on the substrate and formed of a compound containing Ga and As, and a lower portion formed of a compound containing Al and As. An optical resonator having a lower multilayer reflector formed of a periodic structure with a refractive index layer, and an upper multilayer reflector formed of a periodic structure of an upper high refractive index layer and an upper low refractive index layer; A surface-emitting laser element provided between the lower multilayer reflector and the upper multilayer reflector and having an active layer for generating light, wherein the lower multilayer reflector includes phosphorus The warp of the substrate is C (μm), the average strain of the lower multilayer reflector is S (%), the thickness of the substrate is d (μm), and the diameter of the substrate is D (inch). And the film thickness of the lower multilayer reflector is T (μm) In this case, the average distortion of the lower multilayer reflector and the film thickness of the lower multilayer reflector are based on the following formula (5) so that the warp of the substrate satisfies the following formula (4). The phosphorus is a composition corresponding to the average strain S set using the mathematical formula (5) in the relationship between the average strain and the average phosphorus composition included in the lower multilayer mirror. It is included in the lower multilayer film reflecting mirror.

  Here, the average strain is: ((Lattice mismatch degree of the lower high refractive index layer with respect to the substrate × Thickness of the lower high refractive index layer + Lattice mismatch degree of the lower low refractive index layer with respect to the substrate × Lower lower refractive index layer) Thickness)) / (thickness of lower high refractive index layer + thickness of lower low refractive index layer). The average phosphorus composition is ((phosphorus composition ratio of lower high refractive index layer × thickness of lower high refractive index layer + phosphorus composition ratio of lower low refractive index layer × thickness of lower low refractive index layer)) / (The thickness of the lower high refractive index layer + the thickness of the lower low refractive index layer). The phosphorus composition rate means the content of an element containing phosphorus among the elements constituting the lower high refractive index layer and the lower low refractive index layer.

Further, in the surface emitting laser element according to the present invention, the relationship between the average strain and the average phosphorus composition contained in the lower multilayer reflector is such that the average phosphorus composition contained in the lower multilayer reflector is P. It is represented by the following mathematical formula (6).

  The surface emitting laser element according to the present invention is characterized in that an average phosphorus composition contained in the lower multilayer mirror is 0.169% to 2.309%.

  In the surface emitting laser element according to the present invention, the phosphorus is included in the lower low refractive index layer of the lower multilayer reflector, and the phosphorus composition included in the lower low refractive index layer is 0.338%. To 4.621%.

  In the surface emitting laser element according to the present invention, the average phosphorus composition contained in the lower multilayer mirror is 0.41% or more.

  In the surface emitting laser element according to the present invention, the average phosphorus composition contained in the lower multilayer mirror is 1.551% or more.

  According to the surface emitting laser element according to the present invention, the average strain of the lower multilayer reflector and the film thickness of the lower multilayer reflector are set so that the warpage of the substrate satisfies a predetermined condition, When a DBR mirror is formed on a substrate by adding nitrogen to the lower multilayer mirror with a composition corresponding to the set average strain based on the relationship with the average nitrogen composition contained in the multilayer mirror Even so, the occurrence of dislocations can be appropriately suppressed.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the relationship between the thickness and width of each layer, the ratio of each layer, and the like are different from the actual ones. Also in the drawings, there are included portions having different dimensional relationships and ratios.

(Embodiment 1)
FIG. 1 and FIG. 2 are diagrams showing the main configuration of the surface emitting laser element 100 according to the first embodiment. 1 is a plan view, and FIG. 2 is a cross-sectional view taken along the line II-II shown in FIG. As shown in these drawings, the surface emitting laser element 100 includes a lower DBR mirror 2 and an n-type contact layer 3 that function as a lower multilayer reflector that is laminated on a substrate 1 such as a 001 substrate having a plane orientation (001). N-type electrode 4, n-type cladding layer 5, active layer 6, p-type cladding layer 7, current confinement layer 8, p-type cladding layer 9, p-type contact layer 10, p-type electrode 11 and upper multilayer reflector A functioning upper DBR mirror 12 is provided. Among these, the n-type clad layer 5 and the active layer 6, the current confinement layer 8, the p-type clad layer 7 and the p-type clad layer 9 laminated thereon are mesa posts formed into a columnar shape by an etching process or the like. Is formed. The lower DBR mirror 2 may be formed on a GaAs buffer layer stacked on the substrate 1.

  The lower DBR mirror 2 is formed as a semiconductor multilayer mirror in which a plurality of pairs of composite semiconductor layers each having a pair of a GaAs layer functioning as a high refractive index layer and an AlAs layer or AlGaAs layer functioning as a low refractive index layer are stacked. Has been. The thickness of each layer constituting the composite semiconductor layer of the lower DBR mirror 2 is λ / 4n (λ: oscillation wavelength, n: refractive index). The lower DBR mirror 2 is added with nitrogen with a predetermined composition. Nitrogen is introduced into the constituent layers of the lower DBR mirror 2 using an RF plasma nitrogen source in the activated nitrogen state.

  The n-type contact layer 3 is formed on the lower DBR mirror 2 using, for example, n-GaAs. The n-type cladding layer 5 is formed on the n-type contact layer 3 using, for example, n-GaAs. The p-type cladding layer 7 is formed on the active layer 6 described later using, for example, p-GaAs. The p-type cladding layer 9 is formed on a current confinement layer 8 described later using, for example, p-GaAs. The p-type contact layer 10 is formed on the p-type cladding layer 9 using, for example, p-GaAs.

  The current confinement layer 8 is formed on the p-type cladding layer 7 and is composed of an opening 8a as a current confinement opening and a selective oxidation layer 8b. The current confinement layer 8 is formed of an Al-containing layer made of, for example, AlAs. The selective oxidation layer 8b is formed on the annular zone by oxidizing the Al-containing layer by a predetermined range from the outer peripheral portion along the laminated surface. The selective oxidation layer 8b has an insulating property and narrows the current injected from the p-type electrode 11 and concentrates it in the opening 8a, thereby increasing the current density in the active layer 6 immediately below the opening 8a. Yes.

  The active layer 6 has a multiple quantum well (MQW) structure in which, for example, three composite semiconductor layers made of GaInNAs / GaAs are stacked. The active layer 6 is injected from the p-type electrode 11 and is confined by the current confinement layer 8. Based on the measured current, spontaneous emission light in the 1.3 μm band is emitted. The GaInNAs layer functions as a quantum well, and the GaAs layer functions as a barrier layer. The spontaneous emission light is amplified by being resonated and amplified in a direction perpendicular to each layer including the active layer 6 between the lower DBR mirror 2 and the upper DBR mirror 12 as a resonator, and then from the upper surface portion of the upper DBR mirror 12. It is emitted as laser light.

The upper DBR mirror 12 is formed on the p-type contact layer 10. The upper DBR mirror 12 is formed as a dielectric multilayer mirror in which a plurality of pairs of composite dielectric layers made of, for example, SiN / SiO ₂ are stacked, and the thickness of each layer is λ / 4n as in the lower DBR mirror 2. Has been. For example, the upper DBR mirror 12 forms a dielectric multilayer film having a predetermined number of layers in a range including a mesa post, and etches a peripheral region other than the portion directly above the opening 8a in the dielectric multilayer film (etching step). Is formed.

The p-type electrode 11 is stacked on the p-type contact layer 10 and is formed in a ring shape so as to surround the upper DBR mirror 12. On the other hand, the n-type electrode 4 is laminated on the n-type cladding layer 3 and is formed in a C shape so as to surround the bottom surface of the mesa post along the laminated surface. The p-type electrode 11 and the n-type electrode 4 are electrically connected to an external circuit (such as a current supply circuit) (not shown) by a p-type extraction electrode 14 and an n-type extraction electrode 13, respectively. Each semiconductor layer may be grown using a growth method such as MBE, gas source MBE, CBE, or MOCVD. However, when MOCVD is used, dimethylhydrazine (DMHy) or ammonia (NH ₃ ) can be used as a nitrogen source.

  Here, conventionally, when a lower DBR mirror is laminated on a substrate, there has been a problem that dislocation occurs and the reliability of the surface emitting laser element is lowered. This dislocation is caused by the occurrence of lattice mismatch between the substrate and the lower DBR mirror due to strain accumulated in the lower DBR mirror.

In the first embodiment, a sample in which the lattice strain of the lower DBR mirror is actually changed is prepared, and the lattice strain of the lower DBR mirror where dislocations disappear is studied. FIG. 3 is a diagram showing the relationship between the lattice strain and the dislocation density of the lower DBR mirror. The results shown in FIG. 3 show that samples having different lattice strains were created by actually changing the lattice constant by changing the Al composition of the AlGaAs layer among the constituent films constituting the lower DBR mirror. It was obtained based on the result of measuring the dislocation density generated in. The dislocation density referred to here is an aggregate of lattice defect arrays caused by lattice mismatch per 1 mm ² , which was confirmed when the surface was observed with a Nomarski microscope with a Nomarski prism attached to an optical microscope. (Think of what is considered).

As shown in FIG. 3, when the lattice strain of the lower DBR mirror is about 0.14%, the dislocation density, which is as high as about 630 (mm ⁻² ), becomes lower as the lattice strain of the lower DBR mirror becomes lower. It will become. That is, the lattice strain and the dislocation density in the lower DBR mirror have a proportional relationship in which the dislocation density decreases as the lattice strain decreases, as shown by the straight line R1 in FIG. It became clear that it has the relationship shown to the following (7) Formula. In equation (7), the average strain of the lower DBR mirror is S (%), and the generated dislocation density is H (mm ⁻² ).

From this equation (7), it is considered that the dislocation density becomes 0 (mm ⁻² ) by setting the lattice strain of the lower DBR mirror to 0.126% as indicated by the arrow Y1 in FIG. Since the lattice strain and dislocation density of the lower DBR mirror have a proportional relationship that the dislocation density decreases as the lattice strain of the lower DBR mirror decreases, the dislocation disappears when the lattice strain is 0.126% or less. It is considered a thing. That is, it can be said that the upper limit value of the lattice strain of the lower DBR mirror where the dislocation of the lower DBR mirror disappears is 0.126%. Thus, from the result of FIG. 3, it was clarified that the upper limit value of the lattice strain at which the dislocation disappears is 0.126%.

  Next, the lower limit value of the lattice strain of the lower DBR mirror where dislocations disappear is examined. In general, there is a relationship that the lattice strain of the lower DBR mirror increases as the warpage of the substrate increases, and the lattice strain of the lower DBR mirror decreases as the warpage of the substrate decreases. That is, there is a relationship that the lattice strain of the lower DBR mirror changes according to the amount of warpage of the substrate. For this reason, in the first embodiment, the relationship between the amount of warpage of the substrate and the lattice strain of the lower DBR mirror is examined, and the lower portion where dislocation disappears from the relationship between the amount of warpage of the substrate and the lattice strain of the lower DBR mirror. The lower limit value of the lattice strain of the DBR mirror was obtained.

  FIG. 4 is a diagram showing the relationship between the lattice strain of the lower DBR mirror and the amount of warpage of the substrate. The amount of warpage of the substrate refers to the maximum difference between the center of the substrate and the height of the substrate edge, but the amount of warpage of the substrate shown on the horizontal axis in FIG. 4 is converted to the amount of warpage per pair of lower DBR mirrors. It is. Also, the horizontal axis of FIG. 4 shows the average value of the lattice distortion of the lower DBR mirror. FIG. 4 shows a sample S1 having a lower DBR mirror in which the lattice strain is changed by changing the Al composition of the AlGaAs layer on the 450 μm thick substrate, and the AlAs layer on the 450 μm thick substrate. A sample S2 having a DBR mirror in which the lattice strain is changed by changing the composition of nitrogen added to the substrate, and a DBR mirror in which the lattice strain is changed by changing the composition of nitrogen added to the AlAs layer on a 625 μm thick substrate A sample S3 and a sample S4 having a DBR mirror in which the lattice strain is changed by changing the composition of carbon added to the AlAs layer on a substrate having a thickness of 625 μm are measured, and the amount of warpage of the substrate of each sample is measured. And obtained based on the result of conversion into the amount of warpage per pair of the lower DBR mirrors. Here, since the atomic radius of nitrogen and carbon added to the AlAs layer constituting the low refractive index layer of the lower DBR mirror is smaller than that of As, the lattice constant of the AlAs layer is reduced by entering the As site, and the AlAs layer As a low refractive index layer, the entire lower DBR mirror has a function of reducing the lattice distortion.

  Of the straight lines shown in FIG. 4, the straight line R2 indicates the relationship between the lower DBR mirror lattice distortion and the amount of warpage of the substrate when the substrate thickness is 450 μm, and the straight line R3 indicates the substrate thickness of 625 μm. The relationship between the lattice strain and the amount of warpage of the substrate is shown. As shown by straight lines R2 and R3 in FIG. 4, the lattice strain of the lower DBR mirror and the amount of warpage of the substrate are low even when the substrate thickness is 450 μm or 625 μm. As a result, the amount of warpage of the substrate also becomes proportionally lower. That is, it can be said that the lattice strain of the lower DBR mirror and the amount of warpage of the substrate have a proportional relationship in which the amount of warpage of the substrate decreases as the lattice strain decreases.

  As shown in FIG. 4, the lattice strain of the lower DBR mirror in which the amount of warpage of the substrate is zero is about 0.053% regardless of whether the substrate thickness is 450 μm or 625 μm. In other words, from FIG. 4, the amount of warpage of the substrate does not become zero when the lattice strain of the lower DBR mirror is 0%, but the amount of warpage of the substrate when the lattice strain of the lower DBR mirror is about 0.053%. Was found to be zero. As described above, since the relationship between the lattice strain of the lower DBR mirror and the amount of warpage of the substrate shows a proportional relationship regardless of whether the substrate thickness is 450 μm or 625 μm, the lattice strain is 0.053%. It is considered that the amount of warpage of the substrate increases or decreases in proportion to the lattice strain of the lower DBR mirror as the center.

  By the way, the warpage amount of the substrate corresponding to the upper limit value 0.126% of the lattice strain of the lower DBR mirror in which the dislocation disappeared based on FIG. 3 shows a positive value as shown in FIG. Therefore, the upper limit value of 0.126% of the lattice strain of the lower DBR mirror where dislocation disappears corresponds to the amount of warpage when the substrate is warped in the positive direction (when it is convex in the stacking direction of the substrates). It is. As shown in FIG. 3, it is known that the dislocation density decreases as the lattice strain of the lower DBR mirror decreases, and further, the lattice strain of the DBR mirror decreases proportionally as the amount of warpage of the substrate decreases. It will become. Therefore, as shown in FIG. 4, dislocation occurs when the amount of warpage of the substrate is larger than the amount of warpage corresponding to the lattice strain of 0.126%, and the warpage corresponding to the lattice strain of 0.126%. It can be said that dislocation does not occur when the amount of warpage of the substrate is smaller than the amount. In other words, the warpage amount corresponding to the lattice strain of 0.126% is considered to be the upper limit value of the warpage amount of the substrate where no dislocation occurs.

  The amount of warping corresponding to the lattice strain of 0.126% is about 1.8 (μm / period) when the thickness of the substrate is 450 μm, and about 1.8 when the thickness of the substrate is 625 μm. 1.0 (μm / period), both of which correspond to the amount of warpage when the substrate is warped in the positive direction. Here, in addition to warping in the positive direction, the substrate may of course be warped in the negative direction that is opposite to the positive direction (may be convex on the opposite side of the substrate stacking direction). . Even when the substrate warps in the negative direction, the strain amount of the lattice increases in the negative direction as the substrate warps in the negative direction, and dislocations appear.

  For this reason, even when the substrate is warped in the negative direction, it is considered that dislocations due to lattice distortion occur in the same tendency as when the substrate is warped in the positive direction. In other words, it is considered that dislocations also occur when the substrate warps in the negative direction with a warp amount larger than the warp amount corresponding to the lattice strain of 0.126%. It is considered that dislocations do not occur when the substrate warps in the negative direction with a warp amount smaller than the warp amount corresponding to the lattice strain of 0.126%. That is, it is considered that the negative value of the warpage amount corresponding to the lattice strain of 0.126% is the lower limit value of the warpage amount of the substrate where no dislocation occurs. Specifically, when the thickness of the substrate is 450 μm, the warpage amount of about −1.8 (μm / period) is the lower limit value of the warpage amount of the substrate in which dislocation does not occur, and the thickness of the substrate is 625 μm. In this case, the warpage amount of about −1.0 (μm / period) is the lower limit value of the warpage amount of the substrate in which dislocation does not occur.

  As shown in FIG. 4, the amount of warpage of the substrate and the lattice strain are in a proportional relationship so that the amount of warpage of the substrate becomes zero when the lattice strain is about 0.053%. Therefore, the lower limit value of the lattice strain of the lower DBR mirror where dislocation does not occur is based on the relationship between the warpage amount of the substrate and the lattice strain of the lower DBR mirror shown in FIG. It can be obtained in correspondence with the lower limit value. Specifically, as shown in FIG. 4, for example, when the thickness of the substrate is 450 μm, the lower limit value of the warp amount of the substrate is about −1.8 (μm / period). The lower limit of the lattice distortion of the mirror can be determined to be about -0.020%.

  The relationship between the amount of warpage of the substrate and the lattice strain of the lower DBR mirror varies depending on the substrate thickness as shown in FIG. Also, the amount of warpage of the substrate changes depending on the substrate diameter. And since FIG. 4 shows the board | substrate curvature per pair which comprises a DBR mirror, when it converts into the total film thickness of all the pairs of DBR mirrors, ie, the total film thickness of a DBR mirror, The amount of warpage varies.

  Therefore, based on the relationship shown in FIG. 4, considering the substrate thickness, the substrate diameter, and the total film thickness of the DBR mirror, the relationship between the amount of warpage of the substrate caused by the DBR mirror and the amount of lattice distortion of the DBR mirror is shown. The following equation (8) was obtained. In equation (8), the substrate warpage is C (μm), the average strain of the lower DBR mirror is S (%), the substrate thickness is d (μm), and the substrate diameter is D (μm). inch), and the film thickness of the lower DBR mirror is T (μm).

  Substituting the actual sample thickness of 450 μm, substrate diameter of 3 inch, and DBR mirror total thickness of 6.09 μm into equation (8), the substrate corresponding to the upper limit of 0.126% of the lattice strain at which dislocations disappear The amount of warpage C is 61.5 μm. Since the substrate warps not only in the positive direction but also in the negative direction as described above, the range of the warp amount C of the substrate in which dislocation does not occur in this sample is set to −61.5 μm <C <61.5 μm. be able to. Here, since the warpage amount of the substrate where dislocation does not occur varies depending on the substrate thickness and the substrate diameter, when considering the substrate thickness and substrate diameter, the warpage amount C of the substrate where dislocation does not occur is as follows: (9) of the equation can be set. In the equation (9), similarly to the equation (8), the amount of warpage of the substrate is C (μm), the thickness of the substrate is d (μm), and the diameter of the substrate is D (inch).

  As described above, in the first embodiment, since the warpage amount C of the substrate where dislocation does not occur can be set, the lattice strain of the lower DBR mirror and the lower DBR mirror are set so that the warpage amount C of the substrate satisfies the equation (9). Is set based on the above-described equation (8). As a result, in the first embodiment, it is possible to appropriately set the strain (lattice strain) of the lower DBR mirror and the total film thickness of the lower DBR mirror where dislocation does not occur.

  Actually, in the case of a sample having a substrate thickness of 450 μm and a substrate diameter of 3 inches, the range of the warp amount C of the substrate in which dislocation does not occur is −61.5 μm <C <61.5 μm. When the total thickness of the lower DBR mirror is selected to be 6.09 μm, the range of the lattice strain S of the lower DBR mirror that satisfies the warp amount C of the substrate is −0.020% based on the equation (8). <S <0.126% can be obtained. For this reason, in this case, the occurrence of dislocation can be suppressed by controlling the lattice strain of the lower DBR mirror in the range of -0.020% to 0.126%.

  Next, the setting of the lattice strain of the lower DBR mirror that suppresses the occurrence of dislocation will be described. The lattice strain of the lower DBR mirror can be controlled by adding an element other than the constituent element added to the As (arsenic) site. Specifically, by adding nitrogen with a predetermined composition to the low refractive index layer or the high refractive index layer constituting the lower DBR mirror, the lower DBR has a lattice strain that satisfies the warp amount of the substrate that does not generate dislocations. Controls the lattice distortion of the mirror. Nitrogen has a smaller atomic radius than As. For this reason, by adding nitrogen to an As site such as an AlAs layer that forms the low refractive index layer of the lower DBR mirror 2, the lattice constant of the AlAs layer or the like can be reduced to reduce the lattice strain of the entire lower DBR mirror. it can. Of course, even when nitrogen is added to the As site of the GaAs layer forming the high refractive index layer of the lower DBR mirror 2, the lattice constant of the lower DBR mirror can be reduced by reducing the lattice constant of the GaAs layer. is there.

  The relationship between the composition of nitrogen added to the lower DBR mirror and the lattice strain of the lower DBR mirror can be theoretically determined. Specifically, FIG. 5 shows the relationship between the lattice strain of the lower DBR mirror and the nitrogen composition added to the DBR mirror. Here, FIG. 5 shows the calculation of the lattice distortion of the lower DBR mirror when nitrogen of each composition is added to the AlAs layer constituting the low refractive index layer of the lower DBR mirror 2, and the average nitrogen composition in the lower DBR mirror is calculated as follows. It shows the case where it is estimated by the ratio of the thickness of the high refractive index layer and the lower low refractive index layer.

  As indicated by the straight line R4 in FIG. 5, the lattice strain of the lower DBR mirror and the average nitrogen composition in the lower DBR mirror have a proportional relationship theoretically and can be expressed by the following equation (10). In equation (10), the average strain (average lattice strain) of the lower DBR mirror is S (%), and the average nitrogen composition in the DBR mirror is N (%).

  In the first embodiment, the total thickness and lattice distortion of the lower DBR mirror are set using the above equation (8) so that the warpage amount C of the substrate satisfies the above equation (9), which is a condition that does not cause dislocation. To do. In Embodiment 1, nitrogen is included in the lower DBR mirror on the average in the above formula (10) with a composition corresponding to the average strain of the lower DBR mirror set by using the above formula (8). Is set to Thus, in Embodiment 1, the occurrence of dislocations is suppressed by setting the average nitrogen composition contained in the lower DBR mirror using the above equations (8) to (10).

  For example, when a substrate having a substrate thickness of 450 μm and a substrate diameter of 3 inches is actually selected, the range of the warp amount C of the substrate in which dislocation does not occur is −61.5 μm from the above equation (9). Since <C <61.5 μm, if the total film thickness of the lower DBR mirror is further selected to be 6.09 μm, the lattice strain S of the lower DBR mirror satisfying the warpage amount C of the substrate is obtained from the above equation (8). The range of −0.020% <S <0.126%. And the lower DBR mirror average nitrogen composition corresponding to the range of the lattice strain S of this DBR mirror is determined from 0.028% to 0.390% from the above equation (10). In the first embodiment, dislocation generation can be suppressed by adding nitrogen to the lower DBR mirror 2 on the average in the range of 0.028% to 0.390%. In order to add nitrogen on the lower DBR mirror 2 on the average in the range of 0.028% to 0.390%, for example, 0.056% to the AlAs layer constituting the low refractive index layer of the lower DBR mirror 2 is used. Nitrogen may be added in a range of 0.778%.

  As described above, in the first embodiment, the total film thickness of the lower DBR mirror and the above-described equation (8) are satisfied using the above equation (8) so that the warpage amount C of the substrate satisfies the above equation (9), which is a condition that no dislocation occurs. By setting the lattice strain and adding nitrogen to the lower DBR mirror with a composition corresponding to the average strain of the lower DBR mirror set using the above equation (8), the generation of dislocations can be suppressed appropriately A surface emitting laser element can be realized. In particular, in the first embodiment, since it is only necessary to adjust the amount of nitrogen added to the semiconductor material constituting the DBR mirror, a highly reliable surface emitting laser element that appropriately suppresses the occurrence of dislocation can be easily obtained. Can be realized.

  Actually, a surface emitting laser element in which the total film thickness and lattice strain of the lower DBR mirror were set using the above equation (8) so as to satisfy the above equation (9) was created, and the presence or absence of dislocation generation was examined. For example, a substrate having a substrate thickness of 450 μm and a substrate diameter of 3 inches is used, and 30 pairs of GaAs layers (93 nm) / AlAs layers (110 nm) are stacked as the lower DBR mirror so that the total film thickness becomes 6.09 μm. When the nitrogen composition added to the AlAs layer was set to 0.14% so as to be 0.083%, the warpage amount of the substrate was 4.94 μm satisfying the formula (9), and no dislocation occurred. Also, using a substrate having a substrate thickness of 625 μm and a substrate diameter of 3 inches, 30 pairs of GaAs layers (93 nm) / AlAs layers (110 nm) were stacked as the lower DBR mirror so that the total film thickness was 6.09 μm, and the lattice distortion was When the nitrogen composition added to the AlAs layer was set to 0.14% so as to be 0.083%, the warpage amount of the substrate was 12.93 μm that satisfies the formula (9), and no dislocation occurred.

  On the other hand, using a substrate having a substrate thickness of 450 μm and a substrate diameter of 3 inches, 30 pairs of GaAs layers (93 nm) / AlAs layers (110 nm) are laminated as lower DBR mirrors so that the total film thickness becomes 6.10 μm. When nitrogen is not added to the layer and the lattice strain of the lower DBR mirror is 0.138%, which exceeds the upper limit of 0.126%, the warpage amount of the substrate is a value that does not satisfy the equation (9), which is 71.45 μm. It has become. In this case, dislocation occurred. In any of these cases, the wavelength of each output light is 1270 nm.

  Thus, the total film thickness and lattice distortion of the lower DBR mirror are set using the above equation (8) so that the warpage amount C of the substrate satisfies the above equation (9), which is a condition that no dislocation occurs. Based on the equation (10), by adding nitrogen to the lower DBR mirror with a composition corresponding to the average strain of the lower DBR mirror set using the above equation (8), dislocation generation in the surface emitting laser element is generated. It was actually verified that it can be suppressed.

  In the first embodiment, even if the amount of nitrogen added to the lower DBR mirror is further adjusted in consideration of the amount of warpage of the substrate that is increased due to the lamination of the active layer on the lower DBR mirror. Good.

  For example, when a compression strain active layer is laminated on the lower DBR mirror, the amount of warpage of the substrate further increases by about 15 μm. Here, the substrate thickness and the substrate diameter are determined as product specifications, and it is often impossible to reduce the total thickness of the lower DBR mirror in order to ensure reflectivity. For this reason, in this case, the lattice distortion of the lower DBR mirror that can suppress the occurrence of dislocations must be set in consideration of the amount of warpage of the substrate that is increased by the active layer.

Specifically, the lattice strain S ₁ corresponding to the increase in the amount of warpage of the substrate due to the active layer stacking is obtained by performing the following calculation based on the component related to the lattice strain S in the above equation (8).
(27.7 × S ₀ −1.48) /0.2×T= (27.7 × S ₁ −1.48) /0.2×T−15
Substituting the lower limit −0.020% of the lattice strain when the active layer stack is not taken into account as S _{0 in} this equation, and substituting 6.09 μm as T, the increase in the amount of warpage of the substrate due to the active layer stack is increased. A corresponding lattice strain S ₁ of 0.072% is obtained. For this reason, it can be seen that the lower limit value of the lattice strain corresponding to the increase in the amount of warpage of the substrate due to the active layer lamination is 0.072%. The average nitrogen composition in the lower DBR mirror corresponding to the lower limit 0.072% of the lattice strain corresponding to the increase in the amount of warpage of the substrate due to the lamination of the active layer is 0.072% from the equation (10). Further, the upper limit value of the average nitrogen composition in the lower DBR mirror where dislocation does not occur is 0.390% as determined above. For this reason, when an active layer is laminated on the lower DBR mirror 2, the average nitrogen composition in the lower DBR mirror needs to be 0.072% to 0.390% in order to suppress the occurrence of dislocation. That is, when an active layer is stacked on the lower DBR mirror 2, the average nitrogen composition in the lower DBR mirror needs to be 0.072% or more in order to suppress the occurrence of dislocation. Note that the dislocation-free condition in the case of stacking the tensile strain active layer does not change the composition lower limit because the DBR strain is dominant.

  Further, in the first embodiment, the amount of nitrogen added to the lower DBR mirror is further adjusted in consideration of the amount of warpage of the substrate that is increased due to the lamination of the upper DBR mirror on the active layer. Also good.

For example, when an active layer is stacked on the lower DBR mirror and an upper DBR mirror is stacked on the active layer, the amount of warpage of the substrate increases by about 15 μm due to the active layer stacking, and also due to the upper DBR mirror stacking. About 65 μm. That is, when an active layer is laminated on the lower DBR mirror and an upper DBR mirror is laminated on the active layer, the amount of warpage of the substrate increases by about 80 μm. In order to set the lattice strain that can suppress the occurrence of dislocations by further considering the amount of warping of the substrate that further increases when the active layer and the upper DBR mirror are laminated on the lower DBR mirror, the lattice strain of the above formula (8) is set. by performing the following operations component based on the related S, determine the lattice strain S ₂ corresponding to the increase of substrate warpage by the active layer and an upper DBR mirror stack.
_{(27.7 × S 0 -1.48) /0.2×T=} (27.7 × S 2 -1.48) /0.2×T-80

Substituting the lower limit of lattice strain −0.020% when the active layer stack is not taken into account as S _{0 in} this equation, and substituting 6.09 μm as T, the substrate warpage due to the active layer and the upper DBR mirror stack 0.263% as lattice strain _{S 2} corresponding to the increase in the amount is obtained. Therefore, it can be seen that the lower limit value of the lattice strain corresponding to the increase in the amount of warpage of the substrate due to the active layer and the upper DBR mirror lamination is 0.263%. The average nitrogen composition in the lower DBR mirror corresponding to the lower limit value 0.263% of the lattice strain corresponding to the increase in the amount of warpage of the substrate due to the lamination of the active layer and the upper DBR mirror is 0.263% from the equation (10). Further, the upper limit value of the average nitrogen composition in the lower DBR mirror where dislocation does not occur is 0.390% as determined above. For this reason, when the active layer and the upper DBR mirror are stacked on the lower DBR mirror 2, the average nitrogen composition in the lower DBR mirror needs to be 0.263% to 0.390% in order to suppress dislocation generation. There is. That is, when the active layer and the upper DBR mirror are stacked on the lower DBR mirror 2, the average nitrogen composition in the lower DBR mirror needs to be 0.263% or more in order to suppress dislocation generation.

  FIG. 6 shows the result of experimental determination of the relationship between the average nitrogen composition in the lower DBR mirror and the amount of warpage of the substrate. A straight line R5 in FIG. 6 corresponds to a substrate having a thickness of 450 μm, and a straight line R6 corresponds to a substrate having a thickness of 625 μm. As shown by the straight lines in FIG. 6, the relationship between the average nitrogen composition in the DBR mirror and the amount of warpage of the substrate is proportional. As shown in FIG. 5, the relationship between the lattice strain of the lower DBR mirror and the nitrogen composition added to the lower DBR mirror is also proportional. In the above description, the relationship between the lattice strain of the lower DBR mirror and the amount of warp of the substrate shown in FIG. 4 is a proportional relationship, and the lower limit value of the lattice strain that does not suppress the occurrence of dislocation is obtained. Since the relationship between the inner average nitrogen composition and the amount of warpage of the substrate and the relationship between the average nitrogen composition within the DBR mirror and the amount of warpage of the substrate are proportional, the lattice strain of the lower DBR mirror and the amount of warpage of the substrate It is considered that it is reasonable to make the relationship with the proportional relationship also without any problem.

(Embodiment 2)
Next, a second embodiment will be described. FIG. 7 is a cross-sectional view illustrating a configuration of a main part of the surface emitting laser element according to the second embodiment. The surface emitting laser element according to the second embodiment has the same planar configuration as that in FIG. As shown in FIG. 7, the surface emitting laser element 200 according to the second embodiment has a configuration including a lower DBR mirror 202 in place of the lower DBR mirror 2 in the surface emitting laser element 100 shown in FIG. The lower DBR mirror 202 is added with phosphorus (P) having an action of reducing the lattice constant in the same manner as nitrogen, instead of nitrogen. In the second embodiment, the lattice strain of the lower DBR mirror 202 is set in a range in which the occurrence of dislocations can be suppressed by adjusting the amount of phosphorus added that has the effect of reducing the lattice constant.

  In the second embodiment, similarly to the first embodiment, the amount of warpage of the substrate in which dislocation does not occur is obtained, and the lattice distortion of the lower DBR mirror 202 and the total amount of the lower DBR mirror 202 are obtained so that this amount of warpage of the substrate can be realized. Set the film thickness. That is, in the second embodiment, the lattice strain of the lower DBR mirror and the total film thickness of the lower DBR mirror are set based on the above-described equation (8) so that the warpage amount C of the substrate satisfies the equation (9). By doing so, the lattice distortion of the lower DBR mirror and the total film thickness of the lower DBR mirror can be appropriately set as in the first embodiment.

  Then, in order to set the lattice strain of the lower DBR mirror 202 that satisfies the warp amount C of the substrate that does not generate dislocation, the composition range of phosphorus added to the low refractive index layer or the high refractive index layer constituting the lower DBR mirror is set. Set as follows.

  The relationship between the composition of phosphorus added to the lower DBR mirror and the lattice strain of the lower DBR mirror can be theoretically obtained as in the case of nitrogen in the embodiment. Specifically, FIG. 8 shows the relationship between the lattice strain of the lower DBR mirror and the phosphorus composition added to the lower DBR mirror. FIG. 8 shows the lattice distortion of the DBR mirror when phosphorus of each composition is added to the AlAs layer constituting the low refractive index layer of the lower DBR mirror, and the average nitrogen composition in the DBR mirror is calculated from the lower high refractive index layer and the lower refractive index layer. It shows the case where it is estimated by the ratio of the thickness of the low refractive index layer.

  As indicated by a straight line R7 in FIG. 8, the lattice strain of the DBR mirror and the average phosphorus composition in the DBR mirror have a theoretical proportional relationship, and can be expressed by the following equation (11). In the equation (11), the average strain of the lower DBR mirror is S (%), and the average phosphorus composition in the DBR mirror is P (%).

  In the second embodiment, the total thickness and lattice strain of the lower DBR mirror are set using the above equation (8) so that the warpage amount C of the substrate satisfies the above equation (9), which is a condition that does not cause dislocation. To do. In the second embodiment, phosphorus is averaged in the lower DBR mirror with a composition corresponding to the average strain of the lower DBR mirror set using the above equation (8) based on the above equation (11). It is set to be included. Thus, in the second embodiment, by setting the average phosphorus composition contained in the lower DBR mirror using the above equations (8), (9), and (11), the occurrence of dislocation is suppressed. ing.

  For example, when a substrate having a substrate thickness of 450 μm and a substrate diameter of 3 inches is actually selected, the range of the warp amount C of the substrate in which dislocation does not occur is −61.5 μm from the above equation (9). Since <C <61.5 μm, when the total DBR mirror film thickness is selected to be 6.09 μm, the range of the lattice strain S of the DBR mirror satisfying the warp amount C of the substrate is calculated from the above equation (8). Is −0.020% <S <0.126%.

  The lower DBR mirror average phosphorus composition corresponding to the range of the lattice strain S of the DBR mirror is determined from 0.169% to 2.309% from the above equation (11). In the second embodiment, by adding phosphorus on the average to the lower DBR mirror 202 in the range of 0.169% to 2.309%, the occurrence of dislocation can be suppressed. In order to add phosphorus on the lower DBR mirror 202 on the average in the range of 0.169% to 2.309%, for example, phosphorus is added to the GaAs layer constituting the high refractive index layer of the lower DBR mirror 202. Without adding, phosphorus may be added in the range of 0.338% to 4.621% to the AlAs layer constituting the low refractive index layer of the lower DBR mirror 202.

  Thus, in the second embodiment, the total film thickness of the lower DBR mirror and the lower DBR mirror using the above equation (8) so that the warpage amount C of the substrate satisfies the above equation (9), which is a condition that no dislocation occurs. By setting the lattice strain and adding phosphorus to the lower DBR mirror with a composition corresponding to the average strain of the lower DBR mirror set using the above equation (8) obtained from the above equation (11), As in the first embodiment, it is possible to easily realize a highly reliable surface emitting laser element in which dislocation generation is appropriately suppressed.

  In the second embodiment, in the same manner as in the first embodiment, the lower DBR mirror is considered in consideration of the amount of warpage of the substrate that is increased due to the lamination of the compression strain active layer on the lower DBR mirror. The amount of nitrogen to be added may be further adjusted.

Specifically, as in the first embodiment, the amount of warpage of the substrate that is increased when an active layer is stacked on the lower DBR mirror is about 15 μm, and the lower limit value of lattice strain is −0.0195%, DBR Using, for example, 6.09 μm as the total film thickness of the mirror, 0.072% is obtained as the lattice strain S ₁ corresponding to the increase in the amount of warpage of the substrate due to the active layer lamination. The lattice strain S ₁ is the lower limit value of the lattice strain corresponding to an increase in substrate warpage by the active layer stack. The average phosphorus composition in the lower DBR mirror corresponding to the lower limit 0.072% of the lattice strain corresponding to the increase in the amount of warpage of the substrate due to the active layer stacking is 0.41% from the equation (11). Further, the upper limit value of the average phosphorus composition in the lower DBR mirror where dislocation does not occur is 2.29% as determined above. For this reason, when an active layer is laminated on the lower DBR mirror 202, the average phosphorus composition in the lower DBR mirror needs to be 0.41% to 2.29% in order to suppress the occurrence of dislocation. That is, when an active layer is stacked on the lower DBR mirror 202, the average phosphorus composition in the lower DBR mirror needs to be 0.41% or more in order to suppress the occurrence of dislocation. Note that the dislocation-free condition in the case of stacking the tensile strain active layer does not change the composition lower limit because the DBR strain is dominant.

  Further, in the second embodiment, as in the second embodiment, it is added to the lower DBR mirror in consideration of the amount of warpage of the substrate that is increased due to the stacking of the upper DBR mirror on the active layer. The amount of phosphorus to be adjusted may be further adjusted.

Specifically, as in the first embodiment, the amount of warpage of the substrate that is increased when the active layer and the upper DBR mirror are stacked on the lower DBR mirror is set to about 80 μm, and the lower limit value of the lattice strain is −0. Using, for example, 6.09 μm as the total film thickness of the DBR mirror, 0.263% is obtained as the lattice strain S ₂ corresponding to the increase in the amount of warpage of the substrate due to the lamination of the active layer and the upper DBR mirror. The lattice strain S ₂ is a lower limit value of the lattice strain corresponding to an increase in substrate warpage by the active layer and an upper DBR mirror stack. The average phosphorus composition in the lower DBR mirror corresponding to the lower limit value of 0.263% of the lattice strain corresponding to the increase in the amount of warpage of the substrate due to the active layer stacking is 1.551% from the equation (11). Further, the upper limit value of the average phosphorus composition in the lower DBR mirror where dislocation does not occur is 2.29% as determined above. Therefore, when the active layer and the upper DBR mirror are stacked on the lower DBR mirror 202, the average phosphorus composition in the lower DBR mirror is set to 1.551% to 2.29% in order to suppress dislocation generation. There is a need. That is, when the active layer and the upper DBR mirror are stacked on the lower DBR mirror 202, the average phosphorus composition in the lower DBR mirror needs to be 1.551% or more in order to suppress the occurrence of dislocation.

  In the first and second embodiments, the surface emitting laser element in which the active layer 6 is formed of a GaInNAs-based material and the oscillation wavelength is in the 1.3 μm band has been described as an example. The material which comprises an active layer etc. can be selected suitably. For example, an AlGaInP-based material and an InGaAsP-based material can be selected for a surface-emitting laser element whose oscillation wavelength is in the 650 nm band, and an InGaAs-based material is selected for a surface-emitting laser element whose oscillation wavelength is in the 1 μm band. It is possible to select a GaInAsP-based material, an AlGaInAs-based material, and a GaInNAsSb-based material for the surface emitting laser element having an oscillation wavelength in the 1.3 to 1.6 μm band.

In the first and second embodiments described above, the case where the entire upper DBR mirror 12 is configured with a dielectric film has been described as an example. Of course, only a part of the upper DBR mirror 12 is configured with a dielectric film. A part of them may be composed of a semiconductor film, or all may be composed of a semiconductor film. In the first and second embodiments, the dielectric film constituting the upper DBR mirror 12 has been described as being formed using a composite dielectric layer made of, for example, SiN / SiO _2. There is no need to interpret it in a limited manner, and any combination of SiO ₂ , SiN, a-Si, AlO, MgF, ITO, or TiO can be used. In general, SiO, SiN, and a-Si are plasma CVD devices, and SiO, a-Si, AlO, MgF, ITO, and TiO are electron beam evaporation devices, and SiO, a-Si, AlO, and ITO. Can be formed by a sputtering apparatus.

  In the first and second embodiments, the surface emitting laser elements 100 and 200 have been described. However, the present invention is also applicable to a surface emitting laser element array in which the surface emitting laser elements 100 and 200 are arranged one-dimensionally or two-dimensionally. Of course, it is applicable.

It is a top view which shows the structure of the surface emitting laser element concerning embodiment. It is sectional drawing which shows the II-II cross section shown in FIG. It is a figure which shows the relationship between the lattice distortion of a lower DBR mirror, and a dislocation density. It is a figure which shows the relationship between the average distortion (average lattice distortion) of a lower DBR mirror, and the curvature amount of a board | substrate. It is a figure which shows the relationship between the lattice distortion of a lower DBR mirror, and the nitrogen composition added to a DBR mirror. It is a figure which shows the relationship between the average nitrogen composition in a lower DBR mirror, and the curvature amount of a board | substrate. FIG. 6 is a cross-sectional view illustrating a configuration of a main part of a surface emitting laser element according to a second embodiment. It is a figure which shows the relationship between the lattice distortion of a lower DBR mirror, and the nitrogen composition added to a DBR mirror.

Explanation of symbols

100 surface emitting laser element 1 substrate 2,202 lower DBR mirror 3 n-type contact layer 4 n-type electrode 5 n-type cladding layer 6 active layer 7, 9 p-type cladding layer 8 current confinement layer 8a opening 8b selective oxide layer 10 p Type contact layer 11 p-type electrode 12 upper DBR mirror 13 n-type extraction electrode 14 p-type extraction electrode

Claims (11)

A substrate,
Lower multilayer film reflection formed from a periodic structure of a lower high refractive index layer formed by a compound containing Ga and As and a lower low refractive index layer formed by a compound containing Al and As stacked on the substrate An optical resonator having a mirror and an upper multilayer reflector formed of a periodic structure of an upper high-refractive index layer and an upper low-refractive index layer;
An active layer provided between the lower multilayer reflector and the upper multilayer reflector to generate light;
In the surface emitting laser device comprising:
The lower multilayer mirror includes nitrogen,
The warp of the substrate is C (μm), the average strain of the lower multilayer reflector is S (%), the thickness of the substrate is d (μm), the diameter of the substrate is D (inch), When the film thickness of the lower multilayer mirror is T (μm),
The average distortion of the lower multilayer reflector and the film thickness of the lower multilayer reflector are set based on the following formula (2) so that the warp of the substrate satisfies the following formula (1). ,
The nitrogen has a composition corresponding to the average strain S set using the mathematical formula (2) in the relationship between the average strain and the average nitrogen composition contained in the lower multilayer reflector. A surface-emitting laser element characterized by being included in a mirror.

The relationship between the average strain and the average nitrogen composition contained in the lower multilayer reflector is expressed by the following formula (3), where N is the average nitrogen composition contained in the lower multilayer reflector. The surface-emitting laser element according to claim 1.

  3. The surface emitting laser element according to claim 1, wherein an average nitrogen composition contained in the lower multilayer mirror is 0.028% to 0.390%. 4.   4. The surface emitting laser element according to claim 3, wherein an average nitrogen composition contained in the lower multilayer mirror is 0.072% or more.   The surface emitting laser element according to claim 3, wherein an average nitrogen composition contained in the lower multilayer mirror is 0.263% or more. A substrate,
Lower multilayer film reflection formed from a periodic structure of a lower high refractive index layer formed by a compound containing Ga and As and a lower low refractive index layer formed by a compound containing Al and As stacked on the substrate An optical resonator having a mirror and an upper multilayer reflector formed of a periodic structure of an upper high-refractive index layer and an upper low-refractive index layer;
An active layer provided between the lower multilayer reflector and the upper multilayer reflector to generate light;
In the surface emitting laser device comprising:
The lower multilayer mirror includes phosphorus,
The warp of the substrate is C (μm), the average strain of the lower multilayer reflector is S (%), the thickness of the substrate is d (μm), the diameter of the substrate is D (inch), When the film thickness of the lower multilayer mirror is T (μm),
The average strain of the lower multilayer reflector and the film thickness of the lower multilayer reflector are set based on the following formula (5) so that the warp of the substrate satisfies the following formula (4). ,
The phosphorus has a composition corresponding to the average strain S set using the equation (5) in the relationship between the average strain and the average phosphorus composition contained in the lower multilayer reflector. A surface-emitting laser element characterized by being included in a mirror.

The relationship between the average strain and the average phosphorus composition contained in the lower multilayer reflector is expressed by the following formula (6), where P is the average phosphorus composition contained in the lower multilayer reflector. The surface emitting laser element according to claim 6.

  8. The surface emitting laser element according to claim 6, wherein an average phosphorus composition contained in the lower multilayer-film reflective mirror is 0.169% to 2.309%. The phosphorus is included in the lower low refractive index layer of the lower multilayer reflector,
8. The surface emitting laser device according to claim 6, wherein a phosphorus composition contained in the lower low refractive index layer is 0.338% to 4.621%.   9. The surface emitting laser element according to claim 8, wherein an average phosphorus composition contained in the lower multilayer mirror is 0.41% or more.   9. The surface emitting laser element according to claim 8, wherein an average phosphorus composition contained in the lower multilayer-film reflective mirror is 1.551% or more.

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