JP2012195341A - Surface emission type laser element, manufacturing method thereof, surface emission type laser array element, optical scanning device, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface emission type laser technique having a structure which prevents oxidation from a side surface of an AlGaAs layer, AlAs layer or the like which constitutes a lower DBR reflector or the like and has a high Al composition.SOLUTION: A manufacturing method of a surface emission type laser element comprises: a semiconductor layer formation step (S101) of forming a lower reflector, an active layer, a current constriction layer, and an upper reflector by epitaxial growth on a surface of a semiconductor substrate; a mesa structure formation step (S102) of forming a mesa structure by etching a part of a semiconductor film formed by the semiconductor layer formation step; an element isolation groove formation step (S103) of forming an element isolation groove by etching the semiconductor film formed by the semiconductor layer formation step to a surface of the semiconductor substrate; a regrowth layer formation step (S104) of forming a regrowth layer composed of a semiconductor material on a wall surface of the element isolation groove and top and side surfaces of the mesa structure; and a protective film formation step (S105) of forming a protective film composed of an insulator on the regrowth layer.

Description

  The present invention relates to a surface-emitting laser element technology, and more particularly to a surface-emitting laser element that is prevented from being deteriorated due to oxidation, a manufacturing method thereof, a surface-emitting laser array element, an optical scanning device, and an image forming apparatus.

  A surface emitting laser element (VCSEL: Vertical Cavity Surface Emitting Laser) is a semiconductor laser that emits light in a direction perpendicular to a substrate to be formed, and is an edge emitting semiconductor laser element. Compared to low cost, it is relatively easy to make a two-dimensional array, and the high performance makes it possible to form optical communication light sources such as optical interconnections, light sources for optical pickups, and laser printers. It is used for applications such as light sources for devices.

  Specifically, the surface-emitting laser element has a pair of high-reflectivity multilayer DBR (Distributed Bragg Reflector) reflecting mirrors on the surface of the substrate. An active layer is provided between them. A spacer layer is provided between the active layer and the DBR reflector.

  Such a surface emitting laser element can be driven with a low threshold current and low power consumption because the volume of the active layer can be reduced. In addition, since the mode volume in the resonator is small, modulation of several tens of GHz is possible, which is advantageous for high-speed transmission.

  Further, the spread angle of the emitted light is small, and the coupling to the optical fiber is easy. Furthermore, unlike a surface-emitting laser element, a surface-emitting laser element can be formed and manufactured without cleavage, the element area is small, and parallelization and two-dimensional arrangement can be performed at high density. Has advantages.

  Since the surface emitting laser element (VCSEL) has the advantages as described above, it is not limited to application to a light transmission light source such as a LAN (Local Area Network). In the meantime, application to a light source for light transmission in a chip is expected.

  FIG. 10 is a diagram showing a cross-sectional structure of a conventional general surface emitting laser element. Here, the surface emitting laser element refers to each formed as a chip. For the sake of convenience, in this specification, a surface emitting laser is a light emitting point formed on a surface emitting laser element or a surface emitting laser array element.

  As shown in the figure, the conventional general surface emitting laser element includes a lower DBR reflecting mirror 312, a lower spacer layer 313, MQW (equipped by epitaxial growth on an n-type GaAs substrate 311 that is a single crystal substrate. A multiple-quantum well active layer 314, an upper spacer layer 315, a current confinement layer 316 having a current confinement structure that is oxidized at the periphery, an upper DBR reflector 317, and a contact layer 318.

  The lower spacer layer 313, MQW active layer 314, upper spacer layer 315, current confinement layer 316, upper DBR reflector 317 and contact layer 318 have a mesa structure formed by etching, and a protective film 319 is formed on the side surface of the mesa structure. The contact layer 318 is formed and connected to the p-side electrode 321, and the n-side electrode 322 is connected to the back surface of the n-type GaAs substrate 311.

  Next, a method for manufacturing the conventional general surface emitting laser element shown in FIG. 10 will be described. FIG. 11 is a process diagram of a conventional method for manufacturing a general surface emitting laser element.

  First, as shown in FIG. 11 (a), a lower portion is formed on an n-type GaAs substrate 311 by MOCVD (Metal Organic Chemical Vapor Deposition) or MBE (Molecular Beam Epitaxy). The DBR reflecting mirror 312, the lower spacer layer 313, the MQW active layer 314, the upper spacer layer 315, the current confinement layer 316, the upper DBR reflecting mirror 317, and the contact layer 318 are formed by sequentially epitaxial growth.

  The lower DBR reflecting mirror 312 changes the refractive index by changing the composition of n-type AlGaAs, and tens of pairs of n-type AlGaAs serving as a high-refractive index layer and n-type AlGaAs serving as a low-refractive index layer are alternately stacked. To form.

  The lower spacer layer 313 is formed of AlGaAs, the MQW active layer 314 is formed of AlGaAs having different compositions alternately to form a multiple quantum well structure, the upper spacer layer 315 is formed of AlGaAs, and the current confinement layer 316 is formed. Is formed of AlAs.

  Further, the upper DBR reflecting mirror 317 is formed by alternately stacking several tens of pairs of p-type AlGaAs serving as a high refractive index layer and p-type AlGaAs serving as a low refractive index layer, and the contact layer 318 is composed of p-type GaAs. Form.

  Next, as shown in FIG. 4B, the lower spacer layer 313, MQW active layer 314, upper spacer layer 315, current confinement layer 316, upper DBR reflector 317 and contact layer 318 in a predetermined region are etched. Thus, the mesa structure 330 is formed. By forming the mesa structure 330, laser oscillation can be performed efficiently, and parasitic capacitance in high-speed modulation can be reduced.

The mesa structure 330 is formed by forming a SiO ₂ film or SiN film (not shown) on the contact layer 318, applying a photoresist on the SiO ₂ film or SiN film, and forming the mesa structure 330. It develops, after exposing with an exposure apparatus so that a resist pattern may be formed on it.

Using the formed resist pattern as a mask, the SiO ₂ film or SiN film in the region where the resist pattern is not formed is removed by RIE (Reactive Ion Etching) or the like, and the SiO ₂ film or SiN film is removed. A mesa mask is formed.

  Thereafter, another different etching gas is introduced, and the lower spacer layer 313, the MQW active layer 314, the upper spacer layer 315, the current confinement layer 316, the upper DBR reflector 317, the contact in the region where the mesa mask is not formed by RIE or the like. Layer 318 is removed.

Thereafter, the mesa mask made of the SiO ₂ film or the SiN film is removed to form a mesa structure 330 as shown in FIG.

  Dry etching such as RIE is generally used because it can be etched in a direction perpendicular to the n-type GaAs substrate 311, but can also be formed by wet etching.

Next, as shown in FIG. 3C, the current confinement layer 316 is selectively oxidized.
Specifically, after the mesa structure 330 is formed, heat treatment is performed in a water vapor atmosphere, so that the current confinement layer 316 (also referred to as a selective oxidation layer) exposed on the side surface of the mesa structure 330 is oxidized from the etching surface. Let

  As a result, the peripheral portion of the mesa structure 330 is oxidized to become AlxOy which is an insulator, and a selective oxidation region 316a is formed. A current confinement layer 316 is formed by the selective oxidation region 316a and the non-oxidized current confinement region 316b in the central portion to form a current confinement structure.

Next, as shown in FIG. 4D, an element isolation groove 331 for element isolation is formed, and a protective film 319 is further formed.
Specifically, a resist pattern or the like is formed in a region other than the region where the element isolation groove 331 is formed, and etching is performed by dry etching or wet etching until the surface of the n-type GaAs substrate 311 is exposed.

  Note that there is a method of separating by chipping or the like when performing chip separation without forming the element isolation groove 331, but in this case, the side surfaces of the epitaxially grown crystal layer are preferably exposed during element isolation. Absent.

In order to protect the end face, after forming the element isolation groove 331, a SiO ₂ film or a SiN film is formed by CVD (Chemical Vapor Deposition) on the entire surface including the side surface of the mesa structure 330 and the wall surface of the element isolation groove 331. Thus, the protective film 319 is preferably formed.

  Thereafter, the protective film 319 formed on the contact layer 318 is removed by etching to form a p-side electrode 321 connected to the contact layer 318 as shown in FIG. 10, and on the back surface of the n-type GaAs substrate 311. An n-side electrode 322 is formed.

  Thereafter, by separating the elements, a surface emitting laser element can be manufactured. That is, a plurality of surface-emitting laser elements are formed on the substrate and separated into the surface-emitting laser elements. For a surface emitting semiconductor laser element having such a structure and a manufacturing method thereof, refer to Japanese Patent Application Laid-Open No. 2006-302919 (Patent Document 1).

By the way, in the case of manufacturing the above-described conventional surface emitting laser element, the protective film 319 is usually formed of a SiO ₂ film or a SiN film from the viewpoint of insulation.

However, the SiO ₂ film or the SiN film is a material different from other III-V compound semiconductors constituting the surface emitting laser element, and oxygen, water vapor, and the like pass through the protective film 319. It is difficult to form a dense film that does not occur on the side surface of the mesa structure 330 and the wall surface of the element isolation groove 331.

For this reason, even when the protective film 319 made of the SiO ₂ film or the SiN film is formed on the side surface of the mesa structure 330 and the wall surface of the element isolation groove 331, oxygen or water vapor penetrates through the protective film 319 and enters the Al composition. High AlGaAs layer and AlAs layer are gradually oxidized from the side surface of the mesa structure 330 and the wall surface of the element isolation groove 331.

  In particular, the lower DBR reflecting mirror 312 and the upper DBR reflecting mirror 317 are formed by alternately laminating a low refractive index layer having a high Al composition and a high refractive index layer having a low Al composition, and constitute a DBR. The thickness of each layer is formed so that the thickness is an integral multiple of λ / (4 × n) with respect to the laser oscillation wavelength λ, where n is the refractive index. Since several tens of layers are formed, a low refractive index layer having a high Al composition is particularly susceptible to oxidation.

  In general, the surface-emitting laser element is often configured to dissipate heat generated by laser oscillation from the n-type GaAs substrate 311 side. In this case, the low refractive index layer in the lower DBR reflector 312 includes It is advantageous to use an AlAs layer with high conductivity. However, when the element isolation trench 331 is formed, the side surface of the AlAs layer in the lower DBR reflecting mirror 312 is exposed by etching, and thus is easily oxidized by oxygen or water vapor that has entered through the protective film 319.

  As described above, when the AlAs layer constituting the surface emitting laser element, in particular, the lower DBR reflecting mirror 312 is oxidized, the volume of the oxidized layer is changed to generate stress, thereby constituting the surface emitting laser element. The element is destroyed, and this adversely affects the reliability of the device that uses the surface-emitting laser element and the device that uses the surface-emitting laser element.

  Japanese Patent Application Laid-Open No. 2007-235030 (Patent Document 2) proposes a method in which a mesa structure side surface is covered with a semiconductor regrowth layer and protected from oxygen, water vapor, or the like, but is greatly affected by oxygen or water vapor. There is no mention of easy element isolation trenches.

  The present invention has been made in view of the above, and provides a surface-emitting laser having a structure in which oxidation from the side of a layer of AlGaAs, AlAs or the like having a high Al composition constituting a lower DBR reflector is prevented. Furthermore, it is an object of the present invention to provide a highly reliable surface-emitting laser element and a manufacturing method thereof, a surface-emitting laser array element, an optical scanning device, and an image forming apparatus. .

In order to achieve the above object, the present invention has the following configuration.
A method of manufacturing a surface emitting laser device according to the present invention includes a semiconductor layer forming step of forming a lower reflecting mirror, an active layer, a current confinement layer, and an upper reflecting mirror on a substrate, and the semiconductor layer formation. An active layer, a current confinement layer formed by the process, a mesa structure forming step for forming a part of the upper reflector in a mesa structure, a lower reflector, an active layer, a current confinement layer formed by the semiconductor layer forming step, An element isolation groove forming step for removing the upper reflector and forming an element isolation groove, and a regrowth layer forming step for forming a regrowth layer made of a semiconductor material on the wall surface of the element isolation groove, the upper surface and the side surface of the mesa structure It is characterized by having.

  The surface-emitting laser element according to the present invention includes a lower reflector, an active layer, a current confinement layer in which a current confinement structure is formed, and an upper reflector provided on a substrate, A mesa structure formed by a part of the semiconductor layer forming the layer, the current confinement layer, and the upper reflector, an element isolation groove for element isolation provided on the substrate, and a wall surface of the element isolation groove And a regrowth layer made of a semiconductor material provided on the top and side surfaces of the mesa structure.

  The regrowth layer is made of GaInP and has an optical length that is an integral multiple of 1/2 of the wavelength of oscillation light obtained from the active layer.

  Furthermore, a protective film made of an insulator is provided on the regrowth layer.

The protective film is made of SiO ₂ , SiN, or a combination of SiO ₂ and SiN, and the optical length is an integral multiple of 1/2 of the wavelength of oscillation light obtained from the active layer. Features.

  A surface-emitting laser array element according to the present invention includes a plurality of surface-emitting lasers that serve as light emitting points formed on the surface-emitting laser element and are arranged on the same semiconductor substrate.

  An optical scanning device according to the present invention is an optical scanning device that scans a surface to be scanned with a laser beam, the light emitting unit having the surface emitting laser element or the surface emitting laser array element, and the light source. A deflecting unit that deflects one or more laser beams from the unit, and a scanning optical system that condenses the one or more laser beams deflected by the deflecting unit on a surface to be scanned, To do.

  An image forming apparatus according to the present invention includes the surface-emitting laser element or the surface-emitting laser array element as a writing light source, and includes at least one image carrier (photosensitive drum), At least one optical scanning device that scans one or more laser beams modulated by image information with respect to one image carrier, and the image information is color image information, The image carrier is provided for each color element constituting the color image information.

  According to the present invention, since it has a structure that prevents deterioration due to oxidation from the side surface of the AlGaAs, AlAs, etc. layer having a high Al composition that constitutes the lower DBR reflector, etc., it has a long life and high reliability. Type surface-emitting laser element and method for manufacturing the same, and a surface-emitting laser array element and an optical scanning device having high reliability by using a surface-emitting laser formed on the surface-emitting laser element An image forming apparatus can be realized.

1 is a cross-sectional view of a surface emitting laser element according to a first embodiment of the present invention. It is a figure which shows the flow of the manufacturing process of the surface emitting laser element which concerns on the 1st Embodiment of this invention. It is a manufacturing process figure of the surface emitting laser element concerning the 1st Embodiment of this invention. It is a block diagram of the image forming apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the optical scanning device which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the surface emitting laser element array which concerns on the 2nd Embodiment of this invention. It is a block diagram of an image forming apparatus capable of color printing according to a second embodiment of the present invention. It is a figure which shows the outline | summary of the optical transmission module which concerns on 3rd Embodiment. It is a figure which shows the outline | summary of the optical transmission / reception module which concerns on 4th Embodiment. It is sectional drawing of the conventional surface emitting laser element. It is process drawing of the manufacturing method of the conventional surface emitting laser element.

  Embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
A surface-emitting laser element according to the first embodiment of the present invention will be described.
The surface emitting laser element according to the present embodiment is a surface emitting semiconductor laser element formed of a III-V group compound semiconductor.

<Surface emitting laser element>
Hereinafter, the surface emitting laser element according to the present embodiment will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a surface emitting laser element according to this embodiment.

  As shown in the figure, the surface emitting laser element according to the present embodiment includes a lower DBR reflecting mirror (lower semiconductor multilayer film) 3, a lower spacer layer 4, an MQW active layer formed by epitaxial growth on an n-type GaAs substrate 1. A layer 5, an upper spacer layer 6, a current confinement layer 7 (selective oxidation region 7a, current confinement region 7b), an upper DBR reflector (upper semiconductor multilayer film) 8, and a contact layer (p-type GaAs contact layer) 9. Yes.

The lower DBR reflecting mirror 3 is formed by alternately stacking 40.5 pairs of n-type Al _0.3 Ga _0.7 As and n-type AlAs, and Se (selenium) as a dopant is 5 × It is doped with 10 ¹⁷ cm ^{−3 to} 2 × 10 ¹⁸ cm ⁻³ .

The lower DBR reflecting mirror 3 is formed by laminating a low refractive index layer and a high refractive index layer, but a layer formed of n-type AlAs becomes a low refractive index layer, and n-type Al _0.3 Ga. A layer formed of _0.7 As becomes a high refractive index layer.

The MQW active layer 5 is formed of a multiple quantum well structure in which Al _0.1 Ga _0.9 As and Al _0.3 Ga _0.7 As are alternately stacked.

  The current confinement layer 7 is formed of p-type AlAs and is selectively oxidized later to form a current confinement structure including a selective oxidation region 7a and a current confinement region 7b.

The upper DBR reflecting mirror 8 is formed by alternately stacking 21 pairs of p-type Al _0.9 Ga _0.1 As and p-type Al _0.3 Ga _0.7 As. The upper DBR reflecting mirror 8 is doped with Zn as a dopant by 5 × 10 ¹⁷ cm ^{−3 to} 6 × 10 ¹⁸ cm ⁻³ .

The upper DBR reflecting mirror 8 is formed by laminating a low refractive index layer and a high refractive index layer, but a layer formed of p-type Al _0.9 Ga _0.1 As is a low refractive index layer. The layer formed of p-type Al _0.3 Ga _0.7 As is a high refractive index layer.

The contact layer 9 is formed of a film made of p-type GaAs.
Thereafter, the mesa structure 16 is formed by etching the lower spacer layer 4, the MQW active layer 5, the upper spacer layer 6, the current confinement layer 7, the upper DBR reflector 8 and the contact layer 9 in a predetermined region. Then, the AlAs layer which is the current confinement layer 7 is selectively oxidized from the side surface to form the selective oxidation region 7a, and the current confinement region 7b which is not oxidized is left in the central portion.

  In the surface emitting laser element according to the present embodiment, the lower DBR reflector 3, the lower spacer layer 4, the MQW active layer 5, the upper spacer layer 6, the current confinement layer 7, the upper DBR reflector 8 and the contact layer 9 are provided. By etching, an element isolation groove 14 for element isolation is formed. Then, the oxide layer is removed from the entire surface including the wall surfaces of the element isolation trenches 14 and the top and side surfaces of the mesa structure 16 with an etching solution such as phosphoric acid. Further, in the reaction tube for growing the regrowth layer, thermal cleaning is performed in a high-temperature, group V gas atmosphere, and the optical length is obtained from the active layer 5 so as to cover the periphery of the mesa structure 16 and the element isolation groove 14. A GaInP regrowth layer 15 that is an integral multiple of 1/2 of the wavelength of light is formed. Further, a protective film 13 having an optical length that is an integral multiple of 1/2 of the wavelength of the oscillation light obtained from the MQW active layer 5 is formed. In the surface emitting laser element according to the present embodiment, a part of the lower DBR reflecting mirror 3 may be removed when the mesa structure 16 is formed.

  The p-side electrode 11 is formed on the protective film 13 in contact with the contact layer 9 and is formed in ohmic contact with the contact layer 9.

  The n-side electrode 2 is provided on the back surface of the n-type GaAs substrate 1 and is formed in ohmic contact with the n-type GaAs substrate 1.

  In the surface emitting laser element according to the present embodiment, the lower DBR reflecting mirror 3 and the upper DBR reflecting mirror 8 have a structure in which a high refractive index layer and a low refractive index layer are stacked. In order to reduce the electrical resistance at the interface between the layer and the low refractive index layer, a composition gradient layer having a thickness of 20 nm in which the composition of AlGaAs is changed is formed at the interface between the high refractive index layer and the low refractive index layer. Yes.

<Method for Manufacturing Surface Emitting Laser Element>
Next, a method for manufacturing the surface emitting laser element in the present embodiment will be described.
FIG. 2 is a diagram showing the flow of the manufacturing process of the surface emitting laser element according to the present embodiment.

  The surface emitting laser device manufacturing method according to the present invention includes a lower reflecting mirror formed by alternately laminating semiconductor films having different refractive indexes on the surface of a semiconductor substrate, as shown in FIG. Epitaxial growth of a lower spacer layer, an active layer made of a semiconductor film, an upper spacer layer, a current confinement layer made of a semiconductor film, and an upper reflector formed by alternately laminating semiconductor films having different refractive indexes A step of forming a semiconductor layer to be formed (step S101) is performed. Next, a mesa structure forming step (step S102) for forming a mesa structure by etching a part of the semiconductor film formed by the semiconductor layer forming step, and the semiconductor formed by the semiconductor layer forming step An element isolation groove forming step (step S103) for forming an element isolation groove by etching the film to the surface of the semiconductor substrate is performed. Further, a regrowth layer forming step (step S104) is performed in which a regrowth layer made of a semiconductor material is formed on the wall surface of the element isolation trench and on the top and side surfaces of the mesa structure. Then, a protective film forming step (step S105) for forming a protective film made of an insulator on the regrowth layer is performed. A surface emitting laser element is manufactured by performing these steps.

  FIG. 3 is a diagram showing a specific example of the method for manufacturing the surface emitting laser element according to the present embodiment.

  First, although not shown, as shown in step S101 of FIG. 2, MOCVD (Metal Organic Chemical Vapor Deposition) or MBE (Molecular Beam Epitaxy: molecular beam) is formed on the n-type GaAs substrate 1. The lower DBR reflector 3, the MQW active layer 5, the current confinement layer 7, the upper DBR reflector 8 and the contact layer 9 are sequentially formed by epitaxial growth.

The lower DBR reflecting mirror 3 is formed by alternately stacking 40.5 pairs of n-type Al _0.3 Ga _0.7 As serving as a high refractive index layer and n-type AlAs serving as a low refractive index layer.

The MQW active layer 5 forms a multiple quantum well structure by alternately laminating Al _0.1 Ga _0.9 As and Al _0.3 Ga _0.7 As, and the current confinement layer 7 is a p-type. It is made of AlAs.

Further, 21 pairs of p-type Al _0.3 Ga _0.7 As serving as a high refractive index layer and p-type Al _0.9 Ga _0.1 As serving as a low refractive index layer are alternately stacked as the upper DBR reflecting mirror 8. The contact layer 9 is formed of p-type GaAs.

  Next, as described in step S102 of FIG. 2, a mesa structure 16 is formed by etching part of the MQW active layer 5, the current confinement layer 7, the upper DBR reflector 8 and the contact layer 9 in a predetermined region. To do.

  By forming the mesa structure 16, light and current can be confined in the MQW active layer 5, and laser oscillation can be efficiently performed, and parasitic capacitance in high-speed modulation can be reduced.

Specifically, in the surface emitting laser element according to the present embodiment, a SiO ₂ film or a SiN film is formed on the contact layer 9 by CVD or the like, and a photoresist is applied on the SiO ₂ film or the SiN film, A resist pattern is formed on a region where the mesa structure 16 is formed by exposing and developing with an exposure apparatus.

Next, using the formed resist pattern as a mask, the SiO ₂ film or SiN film in the region where the resist pattern is not formed is removed by RIE (Reactive Ion Etching) or the like, and the SiO ₂ film or A protective film serving as a mesa mask made of a SiN film is formed.

Next, using a protective film serving as a mesa mask made of a SiO ₂ film or a SiN film as a mask, a gas such as Cl ₂ , BCl ₃ , SiCl _4, etc. is introduced and the MQW active layer 5, the current confinement layer 7, the upper DBR are formed by RIE or the like. The reflecting mirror 8 and the contact layer 9 are removed.

Although the mesa mask is described as being formed of a SiO ₂ film or a SiN film as an example, it may be formed of only another dielectric film or a resist.

  The mesa structure 16 is formed by the above process. Note that the etching method for forming the mesa structure 16 is a dry etching method such as inductively coupled plasma etching other than RIE (Reactive Ion Etching), a wet etching method, or an etching that combines dry etching and wet etching. It is also possible to carry out by a method.

Next, the current confinement layer 7 is selectively oxidized.
Specifically, after the mesa structure 16 is formed, heat treatment is performed in a water vapor atmosphere, so that oxidation proceeds from the side surface of the current confinement layer 7 exposed by the mesa structure 16.

  As a result, the peripheral portion of the mesa structure 16 is oxidized to form AlxOy, which is an insulator, and the selective oxidation region 7a is formed. This selective oxidation region 7a and the unconfined current confinement region 7b in the central portion form a current confinement structure by a current confinement layer.

Next, step S103 in FIG. 2 is performed, and the element isolation trench 14 is formed as shown in FIG.
Specifically, a resist pattern (not shown) is formed on a region where the element isolation groove 14 is not formed by applying a photoresist, exposing with an exposure apparatus, and developing.

  Thereafter, the lower DBR reflector 3, the lower spacer layer 4, the MQW active layer 5, the upper spacer 6, the layer current confinement layer 7, the upper DBR reflector 8 and the contact layer 9 in the region where the resist pattern is not formed are RIE or the like. The element isolation trench 14 is formed by etching and removing by the above.

An etching method for forming the element isolation trench 14 can be performed by a dry etching method other than RIE (Reactive Ion Etching), a wet etching method, or an etching method combining dry etching and wet etching. is there.
The steps so far are the same as before.

Next, step S104 in FIG. 2 is performed, and as shown in FIG. 3B, a regrowth layer 15 is formed in the state shown in FIG. That is, the regrowth layer 15 is formed after the element isolation trench 14 is formed.
Specifically, it is formed by epitaxially growing a compound semiconductor by MOCVD, MBE or the like. The material for forming the regrowth layer 15 is preferably GaInP which does not contain Al, has only V group element P, is excellent in moisture resistance, has a larger band gap than the AlGaAs active layer, and lattice-matches with GaAs. The reason for not containing Al is that if Al is included, it is easily oxidized.

  Since GaInP is not easy to selectively grow as in the prior art GaAs, it is also grown on the top surface of the mesa structure, and a portion to be contacted with the electrode is etched later, so that the electrode is ohmically connected to GaAs. In this case, GaInP is formed in the light emitting portion, but GaInP has a larger band gap than the AlGaAs active layer and absorbs less oscillation light.

  Further, the regrowth layer 15 is preferably a method by which the regrowth layer 15 having a desired film thickness can be formed on the upper surface and side surfaces of the mesa structure 16 and the wall surface of the element isolation trench 14, and therefore, the regrowth layer 15 is formed by MOCVD. Is preferably formed. Specifically, it is preferable that the optical length is formed on the contact layer 9 in such a manner that it is an integral multiple of 1/2 of the wavelength of the oscillation light obtained from the active layer.

  Since the formed regrowth film 15 is formed by epitaxial growth, it is a dense film and can prevent oxygen from entering from the wall surface of the element isolation trench 14. That is, the formed regrowth film 15 can prevent oxygen from penetrating from the end portion of the surface-emitting laser element, so that the reliability can be improved without being broken by stress or the like.

Next, step S105 of FIG. 2 is performed, and the protective film 13 is formed as shown in FIG.
Specifically, by CVD or the like, the SiO ₂ film, the SiN film, or the SiO film having an optical length that is an integral multiple of λ / 2 with respect to the oscillation wavelength λ of the surface emitting laser element in the present embodiment. _A protective film 13 composed of a combination of _two films and a SiN film is formed.

Next, as shown in FIG. 3D, the p-side electrode 11 and the n-side electrode 2 are formed.
Specifically, a photoresist (not shown) having an opening in a region where the p-side electrode 11 and the contact layer 9 are connected by applying a photoresist on the protective film 13 and performing exposure and development by an exposure apparatus. Form a pattern.

  Thereafter, the protective film 13 in the region where the resist pattern is not formed is removed by performing wet etching with buffered hydrofluoric acid or the like, and the GaInP regrowth layer 15 is removed with hydrochloric acid, sulfuric acid or the like.

  Thereafter, the p-side electrode 11 connected to the contact layer 9 is formed, and the n-side electrode 2 is formed on the back surface of the n-type GaAs substrate 1. Thereafter, the surface-emitting laser element in the present embodiment can be manufactured by separating the surface-emitting laser element along the element isolation groove 14. At this time, even if the element isolation groove 14 is separated by cleavage or the like, the wall surface of the element is not exposed, and the regrowth layer 15 and the protective layer 13 can reliably prevent the entry of oxygen or the like. .

  The contact layer 9 has a structure in which a GaInP regrowth layer 15 and a protective film 13 are laminated. Both have an optical length of λ / mm with respect to the oscillation wavelength λ of the surface emitting laser element in the present embodiment. Since it is formed with a film thickness that is an integral multiple of 2, it does not affect the characteristics of the surface emitting laser element. That is, in order not to affect the characteristics of the surface emitting laser element, the optical lengths of the GaInP regrowth layer 15 and the protective film 13 must be set to film thicknesses that are integer multiples of λ / 2.

  In the surface-emitting laser element according to the present embodiment, the upper surface and side surfaces of the mesa structure 16 and the wall surface of the element isolation groove 14 are covered with a dense GaInP regrowth film 15 formed by epitaxial growth. Therefore, the semiconductor layer can be prevented from being oxidized.

  Accordingly, it is possible to prevent the volume of the semiconductor layer from changing due to the oxidation of the semiconductor layer and applying stress, and the elements constituting the surface emitting laser element from being destroyed, thereby improving the reliability. In particular, even in the case where the element isolation groove 14 is formed in a surface emitting laser element having a structure that can prevent oxidation in the lower DBR reflecting mirror 3 having a structure using a GaAs layer and has a high heat dissipation effect, the reliability of the element is high. It is possible to obtain a surface-emitting type laser element that is highly resistant to oxidation.

<Surface emitting laser array element>
The surface-emitting laser array element in which surface-emitting lasers formed on the above-described highly reliable surface-emitting laser elements are arranged one-dimensionally or two-dimensionally includes a plurality of light sources as described in the embodiments described later. Can be irradiated in parallel, which is useful for high-speed processing.

[Second Embodiment]
The second embodiment of the present invention is an optical electronic apparatus.
Hereinafter, the optical electronic apparatus according to the present embodiment will be described.

  The optical electronic apparatus according to the present embodiment includes any optical electronic apparatus using the surface-emitting laser element or the surface-emitting laser element array according to the first embodiment, and has a surface with little deterioration due to oxidation. By using a light emitting laser element, a stable and long-life optical electronic apparatus can be realized. Hereinafter, an image forming apparatus (laser printer) and an optical disc apparatus will be described as examples of the optical electronic apparatus.

<< Image forming apparatus (laser printer) >>
First, an image forming apparatus (laser printer) will be described as an example of an optical electronic apparatus according to a second embodiment of the present invention. FIG. 4 is a configuration diagram of the image forming apparatus (laser printer) according to the present embodiment.

  As shown in the figure, a laser printer as an image forming apparatus according to the present embodiment includes an optical scanning device 100, a photosensitive drum 101, a charging charger 102, a developing roller 103, a toner cartridge 104, a cleaning blade 105, a paper feed. A tray 106, a paper feed roller 107, a registration roller pair 108, a fixing roller 109, a paper discharge tray 110, a transfer charger 111, a paper discharge roller 112, a charge removal unit 114, and the like are provided.

  Specifically, in the rotation direction of the photosensitive drum 101, the charging charger 102, the developing roller 103, the transfer charger 111, the charge eliminating unit 114, and the cleaning blade 105 are arranged in the vicinity of the photosensitive drum 101 in this order.

  A photosensitive layer is formed on the surface of the photosensitive drum 101. Here, the photosensitive drum 101 is configured to rotate clockwise as shown in the figure. The charging charger 102 has a function of uniformly charging the surface of the photosensitive drum 101.

  The optical scanning device 100 irradiates the surface of the photosensitive drum 101 charged by the charging charger 102 with light modulated based on image information from a host device such as a personal computer. By this light irradiation, a latent image corresponding to the image information is formed on the surface of the photosensitive drum 101.

  The area where the latent image is formed on the surface of the photosensitive drum 101 moves in the direction in which the developing roller 103 is provided as the photosensitive drum 101 rotates. Details of the optical scanning device 100 will be described later.

  The toner cartridge 104 stores toner, and this toner is supplied to the developing roller 103. The developing roller 103 causes the toner supplied from the toner cartridge 104 to adhere to the latent image formed on the surface of the photoconductive drum 101 to visualize the image information on the surface of the photoconductive drum 101.

  Thereafter, as the photosensitive drum 101 rotates, the area where the toner is attached to the latent image on the surface of the photosensitive drum 101 moves in the direction in which the transfer charger 111 is provided.

  Recording paper 113 is stored in the paper feed tray 106. A paper feed roller 107 is disposed in the vicinity of the paper feed tray 106, and the paper feed roller 107 takes out the recording paper 113 one by one from the paper feed tray 106 and conveys it to the registration roller pair 108.

  The registration roller pair 108 is disposed in the vicinity of the transfer charger 111, temporarily holds the recording paper 113 taken out by the paper feeding roller 107, and exposes the recording paper 113 in accordance with the rotation of the photosensitive drum 101. It is sent out toward the gap between the body drum 101 and the transfer charger 111.

  The transfer charger 111 is charged with a reverse polarity to the toner on the surface of the photoconductor 101 in order to electrically attract the toner on the surface of the photoconductor drum 101 to the recording paper 113. The toner on the surface of the photosensitive drum 101 is transferred to the recording paper 113 by this charge, that is, an image formed by the toner is transferred to the recording paper 113. Thereafter, the recording sheet 113 is sent to the fixing roller 109.

  In the fixing roller 109, heat and pressure are applied to the recording paper 113, whereby the toner is fixed on the recording paper 113. Here, the recording paper 113 on which the image is fixed is sent to the paper discharge tray 110 via the paper discharge roller 112, and is sequentially stacked on the paper discharge tray 110.

  The neutralization unit 114 neutralizes the surface of the photosensitive drum 101. The cleaning blade 105 removes toner remaining on the surface of the photosensitive drum 101 (residual toner). The removed residual toner is configured to be reusable. The surface of the photosensitive drum 101 from which the residual toner has been removed moves again in the direction in which the charging charger 102 is provided.

<Optical scanning device>
Next, the optical scanning device according to the present embodiment will be described.
FIG. 5 is a schematic diagram of the optical scanning device 100 according to the present embodiment.

  As shown in the figure, the optical scanning device 100 according to the present embodiment includes a light source unit 121, a coupling lens 122, an aperture plate (aperture) 123, a cylindrical lens 124, a polygon mirror 125, an fθ lens 126, and a toroidal lens 127. Two mirrors 128 and 129 and a main controller (not shown) that controls the above-described units are provided.

  The light source unit 121 includes a surface emitting laser array element in which a plurality of surface emitting semiconductor lasers (surface emitting lasers formed on a surface emitting laser element) according to the first embodiment are formed.

  The coupling lens 122 is for making the laser light emitted from the light source unit 121 substantially parallel light.

  The aperture plate 123 has an aperture and is for defining the beam diameter of the laser light from the coupling lens 122.

  The cylindrical lens 124 condenses the laser light that has passed through the aperture plate 123 on the reflection surface of the polygon mirror 125 via the mirror 128.

  The polygon mirror 125 is formed in a regular hexagonal column shape, and a mirror surface is formed so that the six side surfaces are reflective surfaces. The polygon mirror 125 is rotated at a constant speed in a direction indicated by an arrow by a motor (not shown), and with this rotation, the laser light is deflected at a constant angular velocity.

  The fθ lens 126 has an image height proportional to the incident angle of the laser beam from the polygon mirror 125, and the image plane of the laser beam deflected at a constant angular velocity by the polygon mirror 125 with respect to the main scanning direction. Move at a constant speed.

  The toroidal lens 127 forms an image of the laser beam from the fθ lens 126 on the surface of the photosensitive drum 101 via the mirror 129.

Next, the light source unit 121 according to the present embodiment will be described.
The light source unit 121 includes a surface emitting laser array LA (surface emitting laser array) in which surface emitting lasers of surface emitting laser elements (VCSEL) are two-dimensionally arranged in an array. .

  FIG. 6 is a schematic diagram of a surface emitting laser array LA (surface emitting laser array) constituting the light source unit 121 according to the present embodiment.

  As shown in the figure, in the surface emitting laser array LA (surface emitting laser array), each surface emitting laser is arranged with a predetermined sufficient interval in the main scanning direction. Are arranged while being shifted by an interval d2 in the sub-scanning direction. In this way, an array arranged in the main scanning direction while being shifted by an interval d2 in the sub scanning direction is formed for each pitch d1 in the sub scanning direction.

  By arranging in this way, it is possible to make the interval of the perpendiculars perpendicular to the sub-scanning direction from the center of each surface emitting laser equal (interval d2 is equal). Thus, by controlling the lighting timing of each surface emitting laser, the same configuration as that in the case where the light sources are arranged at narrow regular intervals in the sub-scanning direction on the photosensitive drum 101 can be obtained. .

  For example, when the pitch d1 of the surface emitting semiconductor lasers in the sub-scanning direction is 26.5 μm and ten surface emitting semiconductor lasers are arranged in the main scanning direction, the distance d2 between the surface emitting semiconductor lasers. Is 2.65 μm.

  If the magnification in the optical system is set to double, writing dots can be formed on the photosensitive drum 101 at intervals of 5.3 μm. This corresponds to 4800 dpi (dots / inch), and high-density writing of 4800 dpi can be performed.

  Further, by increasing the number of surface emitting semiconductor lasers arranged in the main scanning direction, narrowing the pitch d1, and further narrowing the interval d2, it is possible to perform writing with higher density. Note that the writing interval in the main scanning direction can be easily controlled by controlling the lighting timing of the surface emitting semiconductor laser as a light source.

  In the optical scanning device according to the present embodiment and the image forming apparatus using the same, since the surface emitting semiconductor laser according to the first embodiment having high reliability is used as the light source, the cost is low. Thus, it is possible to obtain an optical scanning device and an image forming apparatus that have low power consumption, high speed, and high quality.

<Image Forming Apparatus for Forming Color Image>
Next, an image forming apparatus for forming a color image will be described. This image forming apparatus is a color laser printer, which is a dandem color machine having a plurality of photosensitive drums for color images.

  FIG. 7 is a configuration diagram of an image forming apparatus (color laser printer) capable of color printing according to the present embodiment.

  As shown in the drawing, the color laser printer according to the present embodiment includes a black (K) photosensitive drum K1, a charger K2, a developing device K4, a cleaning unit K5, a transfer charging unit K6, and cyan. (C) Photosensitive drum C1, charging device C2, developing device C4, cleaning means C5, transfer charging means C6, magenta (M) photosensitive drum M1, charging device M2, developing device M4, cleaning Means M5, transfer charging means M6, yellow (Y) photosensitive drum Y1, charger Y2, developer Y4, cleaning means Y5, transfer charging means Y6, optical scanning device 100, transfer belt 201 And fixing means 202 and the like.

  In this color laser printer, the optical scanning device 100 has a semiconductor laser for black, a semiconductor laser for cyan, a semiconductor laser for magenta, and a semiconductor laser for yellow. The surface emitting semiconductor laser according to the first embodiment is configured.

  The laser beam from the black semiconductor laser is irradiated to the black photosensitive drum K1, the laser beam from the cyan semiconductor laser is irradiated to the cyan photosensitive drum C1, and the laser from the magenta semiconductor laser. Light is applied to the magenta photosensitive drum M1, and laser light from the yellow semiconductor laser is applied to the yellow photosensitive drum Y1.

  Each of the photosensitive drums K1, C1, M1, and Y1 rotates in the direction of the arrow, and in the order of the rotation direction, each of the chargers K2, C2, M2, and Y2, the developing devices K4, C4, M4, and Y4, for transfer. Charging means K6, C6, M6, Y6 and cleaning means K5, C5, M5, Y5 are arranged.

  Each of the chargers K2, C2, M2, and Y2 uniformly charges the surface of the corresponding photosensitive drum K1, C1, M1, and Y1. A structure in which an electrostatic latent image is formed on the surfaces of the photosensitive drums K1, C1, M1, and Y1 by irradiating the charged surfaces of the photosensitive drums K1, C1, M1, and Y1 with laser light from the optical scanning device 100. It has become.

  Thereafter, toner images are formed on the surfaces of the photosensitive drums K1, C1, M1, and Y1 by the developing units K4, C4, M4, and Y4, and the transfer charging units K6, C6, M6, and Y6 corresponding to the toner images are formed. Thus, the toner images of the respective colors are transferred to the recording paper, and the image is fixed on the recording paper by the fixing unit 202.

  The cleaning units K5, C5, M5, and Y5 remove residual toner remaining on the surfaces of the corresponding photosensitive drums K1, C1, M1, and Y1.

  In this embodiment, the photosensitive drum is described as the image carrier, but the image carrier may be an image forming apparatus using a silver salt film. In this case, a latent image is formed on the silver salt film by optical scanning, and this latent image can be visualized by a process similar to a developing process in a normal silver salt photographic process. Then, it can be transferred to photographic paper by the same process as the printing process in the ordinary silver salt photographic process. Such an image forming apparatus can be implemented as an optical plate making apparatus or an optical drawing apparatus that draws a CT scan image or the like.

  Further, an image forming apparatus using a color developing medium (positive photographic paper) that develops color by the heat energy of a beam spot as an image carrier may be used. In this case, a visible image can be directly formed on the image carrier by optical scanning.

  Although the embodiment according to the present invention has been described above, the above description does not limit the content of the invention, and includes all configurations that can be arbitrarily changed by those skilled in the art based on the conventional laser printer technology. Shall be.

<< Optical disk device >>
Next, an optical disc apparatus will be described as an example of the optical electronic apparatus.

  The optical disc apparatus of this example is a highly reliable surface with little deterioration due to oxidation described in the first embodiment of the present invention as a light source used for writing data on the optical disc and reproducing data written on the optical disc. By using a light emitting laser, a stable and long-life and reliable optical disc apparatus can be realized.

[Third Embodiment]
<Optical transmission module>
The third embodiment is an optical transmission module.
Hereinafter, the optical transmission module according to the present embodiment will be described with reference to the drawings.

  FIG. 8 is a schematic view of an optical transmission module. FIG. 8A shows an optical transmission module using a single surface emitting laser element and a single optical fiber, and FIG. 2 shows an optical transmission module using a surface emitting laser element array made of an optical laser and a plurality of optical fibers corresponding to each of the plurality of optical lasers.

  The optical transmission module 250 using a single surface emitting laser element is emitted from the surface emitting laser element 251 (the surface emitting laser according to the first embodiment) as shown in FIG. The laser beam 252 is input to an optical fiber (plastic optical fiber (POF)) 253 and transmitted to another device.

  The optical transmission module 260 using the surface emitting laser array corresponds to the laser light 262 emitted from each surface emitting laser element constituting the surface emitting laser array 261 as shown in FIG. This is a module that inputs to the optical fiber 263 and transmits it in parallel to other devices.

  In the present embodiment, the surface-emitting laser element is a highly reliable surface-emitting laser element that prevents deterioration of the element due to oxidation according to the first embodiment. A high optical transmission module can be realized. In addition, when an inexpensive POF is used as an optical fiber, a low-cost optical transmission module can be realized, which is effective for short-distance data communication for home use, office indoor use, and equipment.

  Further, when the optical transmission module shown in FIG. 5B is used, high-speed parallel transmission is possible, and more data can be transmitted simultaneously than in the past.

  Further, in the above case, the light emitting laser and the optical fiber are made to correspond one-to-one, but a plurality of surface emitting laser elements having different oscillation wavelengths are arranged in a one-dimensional or two-dimensional array to obtain a wavelength. The transmission rate can be further increased by multiplexing transmission.

[Fourth Embodiment]
<Optical transceiver module>
The fourth embodiment is an optical transceiver module.
Hereinafter, an optical transceiver module according to the present embodiment will be described with reference to the drawings.

  FIG. 9 is a schematic diagram of an optical transceiver module. FIG. 9A shows an optical transceiver module using a single surface emitting laser element, a single light receiving element (photodiode), and an optical fiber corresponding to each. FIG. 2B shows an optical transceiver module using a surface emitting laser array element composed of a plurality of optical lasers, a plurality of light receiving elements (photodiodes), and optical fibers corresponding to the respective elements.

  The optical transceiver module 270 using a single surface emitting laser element and a single light receiving element (photodiode) has a laser beam 272 emitted from the surface emitting laser element 271 as shown in FIG. Is input to an optical fiber (plastic optical fiber (POF)) 273 and transmitted to another device, and a laser beam 276 transmitted from the other device via an optical fiber (plastic optical fiber (POF)) 275 is received as a light receiving element. (Photodiode) This is a module that receives the signal at 277.

  The optical transmission module 280 using the surface emitting laser array element corresponds to the laser light 282 emitted from each surface emitting laser constituting the surface emitting laser array element 281 as shown in FIG. In addition to a module that inputs to an optical fiber 283 and transmits in parallel to another device, a laser beam 286 transmitted from the other device via an optical fiber (plastic optical fiber (POF)) 285 is received by a light receiving element (photodiode) array 287. It is a module that receives in

  In the present embodiment, as the surface emitting laser element, the highly reliable surface emitting laser element or surface emitting laser array element that prevents deterioration of the element due to oxidation according to the first embodiment is used. Therefore, a stable and highly reliable optical transceiver module can be realized. In addition, when an inexpensive POF is used as an optical fiber, a low-cost optical transmission / reception module can be realized, which is effective for short-distance data communication for home use, indoor use in an office, and equipment.

  Further, when the optical transceiver module shown in FIG. 5B is used, high-speed parallel transmission is possible, and more data can be transmitted simultaneously than in the past.

  Further, in the above case, the light emitting laser and the optical fiber are made to correspond one-to-one, but a plurality of surface emitting laser elements having different oscillation wavelengths are arranged in a one-dimensional or two-dimensional array to obtain a wavelength. The transmission rate can be further increased by multiplexing transmission.

[Fifth Embodiment]
<Optical communication system>
The fifth embodiment is an optical communication system.
Hereinafter, the optical communication system according to the present embodiment will be described.

  The optical communication system according to the present embodiment is a system using the optical transmission module according to the third embodiment or the optical transmission / reception module according to the fourth embodiment.

  According to the optical communication system according to the present embodiment, the light according to the third embodiment including the highly reliable surface-emitting laser element that prevents the deterioration of the element due to oxidation according to the first embodiment. Since the transmission module or the optical transmission / reception module according to the fourth embodiment including the highly reliable surface-emitting laser element that prevents deterioration of the element due to oxidation according to the first embodiment is used, A stable, low-cost and highly reliable optical communication system can be realized. Transmission between devices such as computers, data transmission between boards in devices, between LSIs on boards, between elements in LSIs, etc. In particular, it is effective for short-range communication, and an ultrahigh-speed computer system is possible.

  Note that the surface emitting laser element is suitable for a parallel transmission type optical communication system because it can reduce power consumption by an order of magnitude compared to the edge emitting laser element and can easily form a two-dimensional array.

  The embodiments described above are merely examples and do not limit the scope of rights of the present invention. The claims of the present invention are shown not by the above description of the embodiments but by the claims, and are intended to include all modifications within the meaning and scope equivalent to the claims. .

  For example, the surface emitting laser element 251, the surface emitting laser element array 261 in the third embodiment, the surface emitting laser element 271, the light receiving element (photodiode) 277 in the fourth embodiment, and the surface emitting laser. The element array 281 and the light receiving element (photodiode) array 287 may be integrally provided with a control circuit (not shown), and the surface emitting laser element 271 and the light receiving element (photodiode) in the fourth embodiment. 277, the surface emitting laser element array 281 and the light receiving element (photodiode) array 287 may be provided separately or integrally in the same package.

1,311: n-type GaAs substrate 2,322: n-side electrode 3,312: lower DBR reflector (lower semiconductor multilayer film)
4,313: Lower spacer layer 5,314: MQW (Multiple-Quantum Well) active layer (Multiple quantum well layer)
6,315: upper spacer layer 7,316: current confinement layer 7a, 316a: selective oxidation region 7b, 316b: current confinement region 8,317: upper DBR reflector (upper semiconductor multilayer film)
9, 318: p-type GaAs contact layer 11, 321: p-side electrode 13, 319: protective film 14, 331: element isolation groove 15: regrowth layer 16, 330: mesa structure 100: optical scanning device 101: photosensitive drum 102: Charging charger 103: Developing roller 104: Toner cartridge 105: Cleaning blade 106: Paper feed tray 107: Paper feed roller 108: Registration roller pair 109: Fixing roller 110: Paper discharge tray 111: Transfer charger 112: Paper discharge roller 114 : Static elimination unit 121: Light source unit 122: Coupling lens 123: Aperture plate (aperture)
124: Cylindrical lens 125: Polygon mirror 126: fθ lens 127: Toroidal lens 128, 129: Mirror 201: Transfer belt 202: Fixing means 250: Light transmission module 251: Surface emitting laser element 252: Laser light 253: Optical fiber ( Plastic optical fiber (POF)
260: Optical transmission module 261: Surface emitting laser element array 262: Laser light 263: Optical fiber 270: Optical transmission / reception module 271: Surface emitting laser element 272: Laser light 273: Optical fiber (plastic optical fiber (POF))
280: Optical transmission module 281: Surface emitting laser element array 282: Laser light 283: Optical fiber 285: Optical fiber (plastic optical fiber (POF))
286: Laser light 287: Light receiving element (photodiode) array 311: n-type GaAs substrate 312: Lower DBR reflector 313: Lower spacer layer 314: MQW (Multiple-Quantum Well) active layer 315: Upper spacer layer 316: current confinement layer 317: upper DBR reflector 318: contact layer 319: protective film 321: p-side electrode 322: n-side electrode 330: mesa structure LA: surface-emitting laser element array VCSEL: surface-emitting laser element K1: Photoconductor drum for black (K) K2: Charger for black (K) K4: Developer for black (K) K5: Cleaning means for black (K) K6: Charging for transfer for black (K) Means C1: Photosensitive drum for cyan (C) C2: Charger for cyan (C) C4: Developer for cyan (C) 5: Cleaning means for cyan (C) C6: Transfer charging means for cyan (C) M1: Photosensitive drum for magenta (M) M2: Charger for magenta (M) M4: For magenta (M) M5: Cleaning means for magenta (M) M6: Charging means for transfer for magenta (M) Y1: Photosensitive drum for yellow (Y) Y2: Charger for yellow (Y) Y4: Yellow ( Y) Developer Y5: Yellow (Y) cleaning means Y6: Yellow (Y) transfer charging means

JP 2006-302919 A JP 2007-2335030 A

Claims (12)

A semiconductor layer forming step of forming a lower reflector, an active layer, a current confinement layer, and an upper reflector on the substrate;
A mesa structure forming step of forming a part of the active layer, current confinement layer, and upper reflector formed in the semiconductor layer forming step in a mesa structure;
An element isolation groove forming step of forming an element isolation groove by removing the lower reflector, the active layer, the current confinement layer, and the upper reflector formed by the semiconductor layer formation step;
A method of manufacturing a surface emitting laser element, comprising: a regrowth layer forming step of forming a regrowth layer made of a semiconductor material on a wall surface of the element isolation groove and on an upper surface and side surfaces of the mesa structure. A lower reflector provided on the substrate, an active layer, a current confinement layer in which a current confinement structure is formed, and an upper reflector are formed,
A mesa structure formed by a part of the semiconductor layer forming the active layer, the current confinement layer, and the upper reflector;
An element isolation groove for element isolation provided on the substrate;
A surface-emitting laser element comprising: a wall surface of the element isolation groove; and a regrowth layer made of a semiconductor material provided on an upper surface and a side surface of the mesa structure.   The surface emitting laser element according to claim 2, wherein the regrowth layer is made of GaInP.   4. The surface emitting laser element according to claim 2, wherein the regrowth layer has an optical length that is an integral multiple of 1/2 of the wavelength of oscillation light obtained from the active layer.   5. The surface emitting laser element according to claim 2, further comprising a protective film made of an insulator on the regrowth layer. The surface emitting laser element according to claim ₂ , wherein the protective film is made of SiO ₂ , SiN, or a combination of SiO ₂ and SiN.   The surface-emitting laser element according to any one of claims 2 to 6, wherein the protective film has an optical length that is an integral multiple of 1/2 of the wavelength of oscillation light obtained from the active layer. .     8. A surface-emitting laser comprising a plurality of surface-emitting lasers, each of which is a light-emitting point formed on the surface-emitting laser element according to claim 2, arranged on the same semiconductor substrate. Array element. An optical scanning device that scans a surface to be scanned with laser light,
A surface-emitting laser element according to any one of claims 2 to 7, or a light source unit having the surface-emitting laser array element according to claim 8,
Deflecting means for deflecting one or more laser beams from the light source unit;
A scanning optical system for condensing one or a plurality of laser beams deflected by the deflecting unit on a surface to be scanned;
An optical scanning device comprising:   An image forming apparatus comprising the surface-emitting laser element according to claim 2 or the surface-emitting laser array element according to claim 8 as a writing light source. At least one image carrier;
11. The optical scanning device according to claim 9, further comprising at least one optical scanning device that scans the at least one image carrier with one or more laser beams modulated by image information. The image forming apparatus described in 1. 12. The image forming apparatus according to claim 11, wherein the image information is color image information, and the image carrier is provided for each color element constituting the color image information.

Images