JP2008205240A - Surface-emitting semiconductor laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-emitting semiconductor laser which can easily be manufactured by a method of sufficient productivity and can stabilize a polarization direction of a laser beam in one direction. <P>SOLUTION: A lower DBR mirror layer 11, a lower spacer layer 12, an active layer 13, an upper spacer layer 14, a current constriction layer 15, an upper DBR mirror layer 16, a polarization control layer 17 and a contact layer 18 are installed on a substrate 10. The polarization control layer 17 has a lattice constant different from the substrate 10 and has an anisotropic concavo-convex part 17A on a surface of a confronted region with at least a light emitting region 13A. Since reflection factor anisotropy arises in the concavo-convex part 17A, anisotropy of a gain occurs. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surface-emitting type semiconductor laser that emits laser light from its upper surface, and more particularly to a surface-emitting type semiconductor laser that can be suitably applied to applications requiring polarization control.

  A surface emitting semiconductor laser emits light in a direction orthogonal to a substrate, unlike a conventional edge emitting type laser, and a large number of elements are arranged in a two-dimensional array on the same substrate. In recent years, it has attracted attention as a light source for digital copiers and printers.

  Conventionally, this type of surface-emitting type semiconductor laser has a pair of multilayer reflectors formed on a semiconductor substrate, and has an active layer serving as a light emitting region between the pair of multilayer reflectors. One multilayer reflector is provided with a current confinement layer having a structure in which the current injection region is narrowed in order to increase the current injection efficiency into the active layer and reduce the threshold current. Further, a lower electrode is provided on the lower surface side, and a p-side electrode is provided on the upper surface side, and a light emission port is provided on the p-side electrode for emitting laser light. In this surface-emitting type semiconductor laser, a current is confined by a current confinement layer and then injected into an active layer, where it emits light, which is reflected by a pair of multilayer reflectors as a laser beam and emitted from the p-side electrode. It is injected from the exit.

  By the way, the surface emitting semiconductor laser described above generally has non-uniformity in which the polarization direction varies due to variations in elements, and instability in which the polarization direction changes depending on output and environmental temperature. Therefore, when such a surface-emitting type semiconductor laser is applied to a polarization-dependent optical element such as a mirror or a beam splitter, for example, when used as a light source for a digital copying machine or a printer, There is a problem that the variation causes a difference in image formation position and output, and blurring and color unevenness occur.

  In order to solve this problem, several techniques have been reported in which a polarization control function is provided inside a surface emitting semiconductor laser element to stabilize the polarization direction in one direction.

  For example, as one of such techniques, there is one using a high-angle inclined substrate (GaAs inclined substrate) with the (311) plane as a normal. When a surface-emitting type semiconductor laser device is configured using such a high-angle tilted substrate, the gain characteristic with respect to the [−233] direction becomes high, and the polarization direction of the laser light can be controlled in this direction. . Further, the polarization ratio of the laser light is very high, and this is an effective technique for stabilizing the polarization direction of the surface emitting semiconductor laser element in one direction.

  Patent Document 1 discloses a technique for obtaining polarized light parallel to the side surface by narrowing the width in one in-plane direction of the mesa portion so that light is subjected to diffraction loss on the side surface of the mesa portion. ing.

  Further, in Patent Document 2, a discontinuous portion is formed in a part of the metal contact layer that does not affect the characteristics of the laser light emitted from the light emission port, and is parallel to the boundary of the discontinuous portion. A technique for obtaining polarized light forming the following is disclosed.

  Patent Document 3 discloses a technique for oscillating in a specific polarization direction by providing a grating structure in one of the reflection mirrors constituting the vertical resonator.

Japanese Patent No. 2891133 JP-T-2001-525995 Japanese Patent Laid-Open No. 5-21889

  However, the above-mentioned inclined substrate with a high angle is a special substrate having a (311) plane as a normal line, and is therefore very expensive compared to a standard substrate (001) plane or the like. . In addition, when such a high-angle inclined substrate is used, the epitaxial growth conditions such as the growth temperature, doping conditions, and gas flow rate are completely different from those of the (001) plane substrate, so that it is not easy to manufacture easily. .

  Further, in the technique disclosed in Patent Document 1, since the diameter of the mesa portion needs to be extremely small, the resistance of the vertical resonator is increased. Further, the output of the laser beam is as low as about 1 mW, which is not a practical size for use as a light source for a digital copying machine or a printer. In addition, when laser light is emitted from the substrate side, it is necessary to etch off the GaAs substrate to the immediate vicinity of the DBR layer in order to suppress laser absorption by the GaAs substrate, which complicates the manufacturing process. Furthermore, since the mesa portion has a small diameter, it may be damaged in the manufacturing process, and it is not easy to manufacture stably.

  Moreover, in the said patent document 2, what formed the groove | channel (discontinuous part) of the depth of 4.0-4.5 micrometers in the position 7 micrometers away from the edge part of the light emission port is described as an Example. In this way, polarized light that is parallel to the groove is obtained. However, since the polarization direction cannot be stabilized in one direction unless the distance on the short side of the resonance region is reduced to such an extent that the diffraction loss effect occurs, the range in which the diffraction loss effect cannot be obtained (the short side) It seems that the discontinuity formed at a distance of 7 μm) cannot be stabilized. In addition, if such stabilization of the polarization direction is an effect due to stress or strain due to groove formation, the influence of stress from other factors applied to the element during crystal growth or formation process can be considered.

  Further, in Patent Document 3, a method of providing a grating structure in one of the reflection mirrors constituting the vertical resonator is not clarified. However, in order to form a grating structure that can actually control polarization, an electron beam is used. It is necessary to use lithography or the like. Therefore, the technology described in Patent Document 3 is not excellent in mass productivity.

  As described above, in the conventional technique, it is not easy to easily manufacture a surface emitting semiconductor laser element capable of stabilizing the polarization direction of laser light in one direction by a method with high mass productivity. was there.

  The present invention has been made in view of such problems, and the object thereof is surface emission that can be easily manufactured by a mass-productive method and can stabilize the polarization direction of laser light in one direction. It is to provide a type semiconductor laser.

  The surface-emitting type semiconductor laser of the present invention comprises a first multilayer reflector, an active layer having a light emitting region, a second multilayer reflector, and a polarization control layer in this order from the substrate side. The polarization control layer has a lattice constant different from that of the substrate, and has an anisotropic uneven portion at least on the surface of the region facing the light emitting region. In addition, between the substrate and the first multilayer reflector, between the first multilayer reflector and the active layer, between the active layer and the second multilayer reflector, or between the second multilayer reflector and the polarization control. Some layer may be inserted between the layers. Further, the substrate need not be a high-angle inclined substrate such as an (n11) plane substrate (n is an integer), and may be a standard (001) plane substrate.

  In the surface-emitting type semiconductor laser of the present invention, a polarization control layer having an anisotropic concavo-convex portion on at least the surface of the region facing the light emitting region is provided on the second multilayer reflector. As a result, reflectance anisotropy occurs in the concavo-convex portion, and thus gain anisotropy occurs.

  Here, when the concavo-convex portion is formed by arranging a plurality of stripe-shaped convex portions in parallel, the reflectance of light having a polarization direction in the extending direction of the convex portions and the polarization direction in the arrangement direction of the convex portions Therefore, the gain of light having a polarization direction in one of the extending direction of the protrusions and the arrangement direction of the protrusions is different from the gain of light having the polarization direction in the other direction. Is also relatively large.

  In the present invention, since the polarization control layer is formed of a material having a lattice constant different from that of the substrate, the uneven portion of the polarization control layer can be formed by epitaxial crystal growth. That is, the uneven portion can be formed without etching.

  According to the surface-emitting type semiconductor laser of the present invention, since the polarization control layer having an anisotropic uneven portion is provided on the second multilayer mirror at least on the surface of the region facing the light emitting region, the gain Anisotropy can be generated. This makes it possible to stabilize the polarization direction of the laser light in one direction. Further, the concavo-convex portion can be formed by epitaxial crystal growth, and since it is not necessary to use a high-angle inclined substrate, it can be easily manufactured by a method with good mass productivity.

  As described above, the surface-emitting type semiconductor laser of the present invention can be easily manufactured by a method with good mass productivity and can stabilize the polarization direction of the laser light in one direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of a surface emitting semiconductor laser 1 according to an embodiment of the present invention. 2 shows a cross-sectional configuration of the surface-emitting semiconductor laser 1 in FIG. 1 in the direction of arrows AA, and FIG. 3 shows a cross-sectional structure of the surface-emitting type semiconductor laser 1 in FIG. Is. 1 to 3 are schematic representations, and are different from actual dimensions and shapes.

  The surface emitting semiconductor laser 1 includes a lower DBR mirror layer 11 (first multilayer reflector), a lower spacer layer 12, an active layer 13, an upper spacer layer 14, a current confinement layer 15, and an upper DBR on one side of a substrate 10. A laser structure portion in which a mirror layer 16 (second multilayer mirror), a polarization control layer 17 and a contact layer 18 are laminated in this order is provided. Here, the upper portion of the lower spacer layer 12, the active layer 13, the upper spacer layer 14, the current confinement layer 15, the upper DBR mirror layer 16, the polarization control layer 17 and the contact layer 18 are formed up to the contact layer 18, and then the upper surface. The columnar mesa portion 30 having a width of about 40 μm, for example, is formed by being selectively etched.

  The substrate 10, the lower DBR mirror layer 11, the lower spacer layer 12, the active layer 13, the upper spacer layer 14, the upper DBR mirror layer 16, and the contact layer 18 are each composed of, for example, a GaAs (gallium arsenide) based compound semiconductor. Yes. The GaAs compound semiconductor is a compound semiconductor containing at least gallium (Ga) among the group 3B elements in the short period type periodic table and at least arsenic (As) among the group 5B elements in the short period type periodic table. Say.

The substrate 10 is made of, for example, n-type GaAs. The substrate 10 is preferably a standard (001) plane substrate, but may be a high angle inclined substrate such as an (n11) plane substrate (n is an integer). The lower DBR mirror layer 11 is configured, for example, by laminating a plurality of sets of a low refractive index layer and a high refractive index layer. Low refractive index layer, for example a thickness of λ / 4n _a (λ is the oscillation wavelength, _{n a} is the refractive index) n-type _Al x1 _Ga 1-x1 As the (0 <x1 <1), the high refractive index layer, For example, each is formed of n-type Al _x2 Ga _1-x2 As (0 <x2 <x1) having a thickness of λ / 4n _b (where n _b is a refractive index). Examples of the n-type impurity include silicon (Si) and selenium (Se).

The lower spacer layer 12 is made of, for example, Al _x3 Ga _1-x3 As (0 <x3 <1). The active layer 13 is made of, for example, a GaAs material. In the active layer 13, a region facing the current injection region 11C-1 is a light emitting region 13A. The upper spacer layer 14 is made of, for example, Al _x4 Ga _1-x4 As (0 <x4 <1). Here, it is desirable that the lower spacer layer 12, the active layer 13, and the upper spacer layer 14 contain no impurities, but may contain p-type or n-type impurities. Examples of p-type impurities include zinc (Zn), magnesium (Mg), and beryllium (Be).

The current confinement layer 15 has a ring-shaped current confinement region 15A in a region from the side surface of the mesa portion 30 to a predetermined depth, and the other region is a current injection region 15B. Here, the current injection region 15B is made of, for example, p-type Al _x5 Ga _1-x5 As (0 <x5 ≦ 1). The current confinement region 15A includes Al ₂ O ₃ (aluminum oxide) and is obtained by oxidizing a current confinement layer 15D made of p-type Al _x5 Ga _1-x5 As from its side surface, as will be described later. It is a thing. Therefore, the current confinement layer 25 has a function of confining current.

The upper DBR mirror layer 16 is configured by, for example, stacking a plurality of sets of low refractive index layers and high refractive index layers, and the uppermost layer of the upper DBR mirror layer 16 is a high refractive index layer. It has become. Here, the low refractive index layer is, for example p-type Al _x6 Ga _1-x6 As a thickness of λ _/ 4n _{c (n} c is the refractive index) (0 <x6 <1) , the high refractive index layer is, for example, a thickness Saga λ _/ 4n _{d (n} d is a refractive index) are formed by p-type _Al x7 _Ga 1-x7 As the (0 <x7 <x6).

  The contact layer 18 is made of, for example, p-type GaAs. The contact layer 18 may be provided corresponding to the entire upper surface of the mesa unit 30, or may be provided only in a region facing the upper electrode 21 (described later) on the upper surface of the mesa unit 30.

  A protective film 20 is provided on the center and side surfaces of the upper surface of the mesa unit 30 and the surface around the mesa unit 30. An upper electrode 21 is formed on the upper edge of the mesa portion 30 (on the upper surface of the mesa portion 30 where the protective film 20 is not formed) and on the side surface. The upper electrode 21 has an opening 21A at the center of the upper surface of the mesa portion 30. The opening 21A serves as a laser light emission window. A pad portion 22 connected to the upper electrode 21 is formed on the upper surface around the mesa portion 30. A lower electrode 23 is formed on the back surface of the substrate 10.

  Here, the protective film 20 is made of an insulating material such as oxide or nitride. The upper electrode 21 is formed by laminating, for example, a titanium (Ti) layer, a platinum (Pt) layer, and a gold (Au) layer in this order. The upper electrode 21 is electrically connected to the contact layer 18 at the upper edge of the mesa portion 30. Connected. The pad portion 22 is made of the same material as the upper electrode 21 and is electrically connected to the upper electrode 21. The pad portion 22 has a flat plate shape having a surface area sufficient for wire bonding. The lower electrode 23 has, for example, a structure in which an alloy layer of gold (Au) and germanium (Ge), a nickel (Ni) layer, and a gold (Au) layer are sequentially stacked from the substrate 10 side. 10 is electrically connected.

  Next, the polarization control layer 17 that is one of the characteristic portions of the present embodiment will be described.

  For example, the polarization control layer 17 mainly includes InGaP or InAlAs. When the polarization control layer 17 mainly contains InGaP, the In composition ratio of InGaP is larger than 0.6 and smaller than 0.75. When the polarization control layer 17 mainly contains InAlAs, the In composition ratio of InAlAs is larger than 0.12 and smaller than 0.27. That is, the polarization control layer 17 has a lattice constant different from that of the substrate 10 (larger than that of the substrate 10), and a distortion having a magnitude corresponding to the lattice mismatch ratio is generated inside the polarization control layer 17. Yes. Specifically, when the In composition ratio of InGaP is larger than 0.6 and smaller than 0.75, or when the In composition ratio of InAlAs is larger than 0.12 and smaller than 0.27, Is approximately 1% to 2%. Accordingly, it can be said that the In composition ratio of InGaP and the In composition ratio of InAlAs are adjusted to such values that a strain of 1% to 2% is generated inside the polarization control layer 17.

  The polarization control layer 17 has an anisotropic concavo-convex portion 17A on at least the surface of the region facing the light emitting region 13A (see FIGS. 1 and 3). The uneven portion 17A has shape anisotropy, and is formed, for example, by arranging a plurality of stripe-shaped convex portions 17B in parallel. Here, the “stripe shape” is a concept including not only a case where the convex portion 17B is linear, but also a case where the convex portion 17B is wavy, and a case where the width of the convex portion 17B is uneven. The anisotropic shape of the concavo-convex portion 17A is naturally formed by epitaxial crystal growth as will be described later. That is, the concavo-convex portion 17A is not formed through other processes such as etching. As described above, strain of 1% to 2% is generated inside the polarization control layer 17, and the surface of crystal growth is performed by performing epitaxial crystal growth in a state where such large strain is generated. It is possible to form a fine uneven shape.

  When a GaAs substrate having a (001) plane is used as the substrate 10, it is possible to form stripe-shaped convex portions 17B extending in the [-1, 1, 0] direction. The shape of the portion 17A may be cross-hatched due to some influence. In order to prevent such cross-hatching from being formed, it is preferable to use an inclined substrate (off substrate) having a surface different from the (001) surface as the substrate 10. However, when an inclined substrate is used as the substrate 10, it is preferable to lower the inclination angle of the substrate 10 (about 2 to 5 degrees) so that the difficulty of epitaxial crystal growth does not become so high.

  Moreover, since the shape of the concavo-convex portion 17A starts to be formed when the thickness of the polarization control layer 17 exceeds the critical film thickness, in order to form the anisotropic concavo-convex portion 17A on the surface of the polarization control layer 17, It is necessary to grow the crystal until it becomes at least thicker than the critical film thickness. That is, the portion of the polarization control layer 17 excluding the concavo-convex portion 17A has a thickness greater than or equal to the critical film thickness.

  The surface emitting semiconductor laser 1 according to the present embodiment can be manufactured, for example, as follows.

  7A, 7B to 9A, 9B show the manufacturing method in the order of steps. 7A, 7B, 8A, and 8B are cross-sectional views taken along the same direction as the direction of arrows BB in FIG. 9 (A) and 9 (B) each represent a configuration of a cross section obtained by cutting an element in the manufacturing process in the same direction as the direction of arrows AA in FIG.

The compound semiconductor layer on the substrate 10 made of GaAs is formed by, for example, MOCVD (Metal Organic Chemical Vapor Deposition) method. At this time, for example, trimethylaluminum (TMA), trimethylgallium (TMG), trimethylindium (TMIn), and arsine (AsH3) are used as the raw material of the III-V group compound semiconductor. Phosphine (PH ₃ ), donor impurities For example, H2 Se is used as a raw material, and dimethyl zinc (DMZ) is used as a raw material for acceptor impurities.

  First, as shown in FIG. 4A, on the substrate 10, the lower DBR mirror layer 11, the lower spacer layer 12, the active layer 13, the upper spacer layer 14, the current confinement layer 15D, the upper DBR mirror layer 16, the polarization The control layer 17 and the contact layer 18 are laminated in this order.

  At this time, as shown in FIG. 4B, since the uneven portion 17A is formed on the upper surface of the polarization control layer 17, an uneven shape is also formed on the upper surface of the contact layer 18 formed thereon.

  Next, after forming a resist layer (not shown), the contact layer 18, the polarization control layer 17, the upper DBR mirror layer 16, the current confinement layer 15D, for example, by reactive ion etching (RIE) method. The mesa portion 30 is formed by selectively removing a part of the upper spacer layer 14, the active layer 13 and the lower spacer layer 12.

  Next, an oxidation process is performed at a high temperature in a water vapor atmosphere to selectively oxidize Al in the current confinement layer 15D from the outside of the mesa unit 30. Thereby, the edge portion of the current confinement layer 15D becomes an insulating layer (aluminum oxide). That is, the current confinement layer 11C is formed in which the edge portion is the current confinement region 11C-2 and only the central region is the current injection region 11C-1.

  Next, the above-described insulating material is deposited on the surface of the mesa portion 30 and the upper surface around it by, for example, a CVD (Chemical Vapor Deposition) method. Thereafter, a portion of the insulating material corresponding to the upper edge portion of the mesa portion 30 is selectively removed by etching. Thereby, the protective film 20 is formed. Note that an insulating material having a different material or thickness from the side surface of the mesa unit 30 and the upper surface of the periphery thereof may be formed in a separate step with respect to the central portion of the upper surface of the mesa unit 30.

  Next, after laminating the aforementioned metal material on the mesa unit 30 and the peripheral substrate of the mesa unit 30 by, for example, a vacuum deposition method, an opening 21A is provided at the center of the upper surface of the mesa unit 30 by, for example, selective etching. The upper electrode 21 is formed, and the pad portion 22 is formed on the surface around the mesa portion 30.

  Next, after the back surface of the substrate 10 is appropriately polished and the thickness thereof is adjusted, the lower electrode 23 is formed on the back surface of the substrate 10. In this way, the surface emitting semiconductor laser 1 is manufactured.

  In the surface emitting semiconductor laser 1 having such a configuration, when a predetermined voltage is applied between the lower electrode 23 and the upper electrode 21, current is injected into the active layer 13 through the current injection region 15A in the current confinement layer 15. As a result, light emission is caused by recombination of electrons and holes. This light is reflected by the pair of lower DBR mirror layer 11 and upper DBR mirror layer 16, causes laser oscillation at a predetermined wavelength, and is emitted to the outside as a laser beam.

  At this time, in the present embodiment, a polarization control layer 17 having an anisotropic uneven portion 17A is provided on the upper DBR mirror layer 16 at least on the surface of the region facing the light emitting region 13A. Thereby, since the reflectance anisotropy occurs in the uneven portion 17A, anisotropy of the gain occurs. Here, since the concavo-convex portion 17A is formed by arranging a plurality of stripe-shaped convex portions 17B in parallel, the reflectance of light having a polarization direction in the extending direction of the convex portion 17B and the arrangement direction of the convex portions 17B. The reflectance of light having a polarization direction is different from each other. In the present embodiment, the reflectance of light having the polarization direction in the extending direction of the convex portion 17B is greater than the reflectance of light having the polarization direction in the arrangement direction of the convex portions. The gain of the light having the polarization direction in the existing direction is larger than the gain of the light having the polarization direction in the arrangement direction of the convex portions. As a result, the polarization direction of the laser light can be stabilized in one direction.

  For example, when a GaAs substrate having a (001) plane or a tilted substrate having a plane slightly inclined (about 2 to 5 degrees) from the (001) plane is used as the substrate 10, [-1, 1, 0 The stripe-shaped projections 17B extending in the direction of [] are formed, and the reflectance of the light having the polarization direction in the [-1, 1, 0] direction has the polarization direction in the [1, 1, 0] direction. It becomes larger than the reflectance of light. As a result, the gain of light having a polarization direction in the [-1, 1, 0] direction is larger than the gain of light having a polarization direction in the [1, 1, 0] direction. It is possible to align in the 1,1,0] direction.

  In the present embodiment, since the polarization control layer 17 is formed of a material having a lattice constant different from that of the substrate 10, the uneven portion 17A of the polarization control layer 17 can be formed by epitaxial crystal growth. . That is, the uneven portion can be formed without etching. Further, it is not necessary to use a high-angle inclined substrate in order to form the uneven portion 17A. Therefore, it can be easily manufactured by a method with good mass productivity.

  Thus, the surface-emitting type semiconductor laser 1 of the present embodiment can be easily manufactured by a method with good mass productivity, and the polarization direction of the laser light can be stabilized in one direction.

  The present invention has been described with reference to the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made.

  For example, in the embodiment described above, when the polarization control layer 17 mainly contains InGaP, the In composition ratio of InGaP is adjusted to form the uneven portion 17A as a result. As a result, it is possible to form the concavo-convex portion 17A by adjusting the composition ratio of Sb within a range of larger than 0.016 and smaller than 0.064 as a group III ratio.

  Moreover, in the said embodiment, although the contact layer 17 and the protective film 20 were provided on the part facing the opening part 21A among the polarization control layers 17, these may be eliminated.

  In the above embodiment, the present invention has been described by taking a GaAs compound semiconductor laser as an example. However, other compound semiconductor lasers such as GaInP, AlGaInP, InGaAs, GaInP, InP, GaN, The present invention is also applicable to compound semiconductor lasers such as GaInN-based and GaInNAs-based.

1 is a perspective view of a surface emitting semiconductor laser according to an embodiment of the present invention. It is a cross-sectional block diagram of the AA arrow direction of the laser of FIG. It is a cross-sectional block diagram of the BB arrow direction of the laser of FIG. FIG. 2 is a cross-sectional configuration diagram for explaining a manufacturing process of the laser of FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Surface emitting semiconductor laser, 10 ... Substrate, 11 ... Lower DBR mirror layer, 12 ... Lower spacer layer, 13 ... Active layer, 13A ... Light emitting region, 14 ... Upper spacer layer, 15, 15D ... Current confinement layer, 15A DESCRIPTION OF SYMBOLS ... Current injection area | region, 15B ... Current confinement area | region, 16 ... Upper DBR mirror layer, 17 ... Polarization control layer, 17A ... Uneven part, 17B ... Convex part, 18 ... Contact layer, 20 ... Protective film, 21 ... Upper electrode, 21A ... Opening part, 22 ... Pad part, 23 ... Lower electrode, 30 ... Mesa part.

Claims (10)

On the substrate, the first multilayer reflector, the active layer, the second multilayer reflector and the polarization control layer are provided in this order from the substrate side,
The surface-emitting type semiconductor laser, wherein the polarization control layer has a lattice constant different from that of the substrate and has a plurality of stripe-shaped convex portions arranged in parallel on at least a part of the surface. The active layer has a light emitting region;
Each said convex part is formed in the surface of the area | region facing at least the said light emission area | region. The surface emitting semiconductor laser characterized by the above-mentioned. The surface-emitting type semiconductor laser according to claim 1, wherein each of the convex portions is formed by epitaxial crystal growth. 2. The surface-emitting type semiconductor laser according to claim 1, wherein a portion of the polarization control layer excluding the convex portions has a thickness equal to or greater than a critical thickness. The substrate mainly comprises GaAs;
The surface emitting semiconductor laser according to claim 1, wherein the polarization control layer mainly contains InGaP or InAlAs. The surface-emitting type semiconductor laser according to claim 5, wherein the polarization control layer has a larger lattice constant than the substrate. The surface emitting semiconductor laser according to claim 5, wherein when the polarization control layer mainly contains InGaP, the In composition ratio is larger than 0.6 and smaller than 0.75. The surface emitting semiconductor laser according to claim 5, wherein when the polarization control layer mainly contains InAlAs, the In composition ratio is larger than 0.12 and smaller than 0.27. The surface emitting semiconductor laser according to claim 1, wherein the substrate is a substrate having a (001) plane. The surface emitting semiconductor laser according to claim 1, wherein the substrate is an inclined substrate having a surface inclined from a (001) plane.

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