JP2011142209A - Semiconductor laser element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser element capable of stably operating even at high humidity. <P>SOLUTION: The semiconductor laser element includes a substrate 101, a first electrode 113, a second electrode 117, a first reflector 102, a second reflector 120, a resonator 130 disposed between the first reflector and the second reflector and including an active layer 105 and a current constriction layer 107, a mesa post 110 formed on one principal surface of the substrate 101 and including the current constriction layer 107, a passivation film 123 covering the mesa post 110 and the one principal surface of the substrate 101, and a moisture-resistive metal film 133 which covers a base of the mesa post 110. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor laser device, and more particularly to a vertical cavity surface emitting laser (VCSEL).

As this type of surface emitting semiconductor laser element, a vertical resonator provided with a resonator in which a plurality of semiconductor layers including an active layer are stacked between upper and lower multilayer mirrors, which are DBR (Distributed Bragg Reflector) mirrors. Type surface emitting semiconductor laser elements are disclosed (see Patent Documents 1 and 2). In addition, the surface emitting semiconductor laser elements disclosed in Patent Documents 1 and 2 have a mesa post structure, and a current confinement layer is provided on the mesa post for limiting the current path and increasing the current injection efficiency. This current confinement layer has a current confinement portion made of an oxide insulator such as Al ₂ O ₃ located on the outer periphery and a current injection portion located in the center of the current confinement portion and made of an Al-containing compound semiconductor such as AlAs. Is. This current injection portion serves as a current path when current is injected into the surface emitting semiconductor laser element, and also serves as an opening through which laser light is emitted.

  However, when the semiconductor laser device having such a structure is operated under high humidity, there is a problem that reliability is lowered.

JP 2008-10827 A JP 2007-258581 A

  Accordingly, a main object of the present invention is to provide a semiconductor laser device which can operate stably even under high humidity.

  As a result of diligent research, the present inventors have found that the surface-emitting type semiconductor laser device as described above includes a passivation film made of a dielectric, but a portion of the passivation film transmits moisture, It has been found that the reliability under humidity is reduced.

The present invention is based on such knowledge, and according to the present invention,
A substrate,
A first electrode;
A second electrode;
A first reflector;
A second reflector;
A resonator formed between the first reflecting mirror and the second reflecting mirror, which narrows a current path between an active layer, the first electrode, and the second electrode. The resonator comprising a layer;
A protrusion formed on one principal surface of the substrate, the protrusion including the current confinement layer;
A passivation film covering the convex portion and one main surface of the substrate;
There is provided a semiconductor laser device comprising a moisture-resistant metal film that covers the base of the convex part directly or via the passivation film.

  Preferably, a base portion of the convex portion is covered with the passivation film, and further, the base portion is covered with the moisture-resistant metal film provided on the passivation film via the passivation film.

  The moisture-resistant metal film is preferably any metal selected from the group consisting of an Au film, a two-layer film of an Au film and an underlying Pt film, and an Au film and a two-layer film of an Mo film thereunder It is a membrane.

  In addition, it preferably further includes an adhesion improving metal film provided under the moisture resistant metal film and improving the adhesion between the moisture resistant metal film and the passivation film.

  The metal film for improving adhesion is preferably any metal film selected from the group consisting of Ti, Cr and Pd.

  The semiconductor laser element preferably further includes an electrode pad and an extraction electrode that connects the first electrode and the electrode pad, and the first electrode is provided on an upper surface of the convex portion, The extraction electrode and the moisture-resistant metal film are electrically connected.

  The semiconductor laser device further includes an electrode pad and a lead electrode connecting the first electrode and the electrode pad, the first electrode being provided on an upper surface of the convex portion, A second passivation film is provided between the extraction electrode and the moisture-resistant metal film, and the extraction electrode and the moisture-resistant metal film may not be electrically connected.

  Preferably, the base of the convex portion is covered with the moisture-resistant metal and further covered with the passivation film provided on the moisture-resistant metal.

  In this case, the moisture-resistant metal film is an alloy film of Ni, Cr, and Al or a silicide film of Ni and Cr.

  Preferably, the semiconductor laser element includes a third passivation film that covers the passivation film and the moisture-resistant metal, a second moisture-resistant metal film that covers a step portion of the third passivation film, Is further provided.

Preferably, the semiconductor laser element includes a third passivation film that covers the passivation film, the first electrode, the extraction electrode, and the moisture-resistant metal;
And a second moisture-resistant metal film covering the step portion of the third passivation film.

  Preferably, the second moisture-resistant metal film is selected from the group consisting of an Au film, a two-layer film of an Au film and an underlying Pt film, and a two-layer film of an Au film and an underlying Mo film. This metal film.

  Preferably, a second adhesion-improving metal film provided under the second moisture-resistant metal film and improving adhesion between the second moisture-resistant metal film and the third passivation film. Is further provided.

  Preferably, the second adhesion improving metal film is any metal film selected from the group consisting of Ti, Cr and Pd.

Preferably, the semiconductor laser element is
A semiconductor layer provided on the one principal surface of the semiconductor substrate;
A second electrode pad;
A second lead electrode connecting the second electrode and the second electrode pad; and
The convex portion is provided on the semiconductor layer, the convex portion includes the active layer, and the second electrode is provided on the semiconductor layer so as to be separated from the convex portion,
The third passivation film further covers the semiconductor layer, the second electrode, and the second lead electrode.

  Preferably, the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the passivation film is a part of the dielectric multilayer film reflecting mirror.

  Preferably, the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the second passivation film is a part of the dielectric multilayer film reflecting mirror.

  Preferably, the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the third passivation film is a part of the dielectric multilayer film reflecting mirror.

Preferably, the dielectric multilayer film reflecting mirror is composed of a plurality of pairs of SiO ₂ / SiN _x .

  Preferably, the current confinement layer includes an aluminum-containing compound semiconductor layer, and an oxide insulator layer provided around the aluminum-containing compound semiconductor layer and obtained by oxidizing the aluminum-containing compound semiconductor layer. .

  Preferably, the semiconductor laser device further includes a planarization dielectric film provided on the passivation film and the moisture-resistant metal.

  In this case, preferably, the semiconductor laser element further includes an electrode pad and an extraction electrode that connects the first electrode and the electrode pad, and the first electrode is provided on an upper surface of the convex portion. The lead electrode and the electrode pad are provided on the planarizing dielectric film.

Moreover, according to the present invention,
A substrate,
A first electrode;
A second electrode;
A first reflector;
A second reflector;
A resonator formed between the first reflecting mirror and the second reflecting mirror, which narrows a current path between an active layer, the first electrode, and the second electrode. The resonator comprising a layer;
A protrusion formed on one principal surface of the substrate, the protrusion including the current confinement layer;
A passivation film covering the convex portion and one main surface of the substrate;
There is provided a semiconductor laser device comprising a moisture-resistant metal film covering a bent portion of the passivation film.

  Preferably, the semiconductor laser element further includes an electrode pad, and an extraction electrode that connects the first electrode and the electrode pad, and the first electrode is provided on an upper surface of the convex portion, and the passivation is performed. The film further covers the first electrode and the electrode pad.

Preferably, the semiconductor laser element connects a semiconductor layer provided on the one main surface of the semiconductor substrate, a second electrode pad, the second electrode, and the second electrode pad. A second extraction electrode that includes:
The convex portion is provided on the semiconductor layer, the convex portion includes the active layer, and the second electrode is provided on the semiconductor layer so as to be separated from the convex portion,
The passivation film further covers the semiconductor layer, the second electrode, and the second extraction electrode.

  Preferably, the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the passivation film is a part of the dielectric multilayer film reflecting mirror or the dielectric multilayer film reflecting mirror.

  According to the present invention, there is provided a laser array including a plurality of any of the semiconductor laser elements described above.

  Moreover, according to this invention, an optical apparatus provided with one of the said semiconductor laser elements is provided.

  Moreover, according to this invention, a communication system provided with one of the said semiconductor laser elements is provided.

  According to the present invention, a semiconductor laser device that can operate stably even under high humidity is provided.

It is a schematic plan view for demonstrating the structure of the surface emitting semiconductor laser element of the preferable 1st Embodiment of this invention, and its manufacturing method. FIG. 2 is a schematic vertical sectional view taken along line X1-X1 of FIG. It is a schematic longitudinal cross-sectional view for demonstrating the structure of the surface emitting semiconductor laser element of the preferable 2nd Embodiment of this invention, and its manufacturing method. It is a schematic longitudinal cross-sectional view for demonstrating the structure of the surface emitting semiconductor laser element of the preferable 3rd Embodiment of this invention, and its manufacturing method. It is a schematic longitudinal cross-sectional view for demonstrating the structure of the surface emitting semiconductor laser element of the preferable 4th Embodiment of this invention, and its manufacturing method. It is a schematic plan view for demonstrating the structure of the surface emitting semiconductor laser element of the preferable 5th Embodiment of this invention, and its manufacturing method. It is a X2-X2 line schematic longitudinal cross-sectional view of FIG. 1 is a schematic perspective view for explaining a surface emitting laser array using a plurality of surface emitting semiconductor laser elements according to preferred first to fifth embodiments of the present invention. FIG. It is a schematic plan view for explaining a surface emitting laser array chip using a plurality of surface emitting semiconductor laser elements according to preferred first to fifth embodiments of the present invention. It is a schematic longitudinal cross-sectional view for demonstrating the surface emitting laser package using the surface emitting semiconductor laser element of the preferable 1st-5th embodiment of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the optical disk pick-up using the surface emitting semiconductor laser element of the preferable 1st-5th embodiment of this invention. It is a schematic plan view for demonstrating the optical transmission / reception module using the surface emitting semiconductor laser element of the preferable 1st-5th embodiment of this invention. Optical coupling structure of surface emitting semiconductor laser elements and optical waveguides according to preferred first to fifth embodiments of the present invention, or surface emitting semiconductor laser elements according to preferred first to fifth embodiments of the present invention. It is a schematic longitudinal cross-sectional view for demonstrating the optical coupling structure of the surface emitting laser array using two or more and an optical waveguide. Optical coupling structure of surface emitting semiconductor laser elements and optical waveguides according to preferred first to fifth embodiments of the present invention, or surface emitting semiconductor laser elements according to preferred first to fifth embodiments of the present invention. It is a schematic longitudinal cross-sectional view for demonstrating the optical coupling structure of the surface emitting laser array using two or more and an optical waveguide. Optical coupling structure of surface emitting semiconductor laser elements and optical waveguides according to preferred first to fifth embodiments of the present invention, or surface emitting semiconductor laser elements according to preferred first to fifth embodiments of the present invention. It is a schematic longitudinal cross-sectional view for demonstrating the optical coupling structure of the surface emitting laser array using two or more and an optical waveguide. A communication system using the surface emitting semiconductor laser elements according to the first to fifth preferred embodiments of the present invention, or a plurality of surface emitting semiconductor laser elements according to the first to fifth preferred embodiments of the present invention. It is a schematic block diagram for demonstrating the communication system using the surface emitting laser array which was used.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below.

(First embodiment)
A preferred first embodiment of the present invention will be described with reference to FIGS. Referring to FIGS. 1 and 2, the semiconductor laser element of the present embodiment is a surface emitting semiconductor laser element. The surface emitting semiconductor laser element 100 is formed on a substrate 101 and the substrate 101. Lower DBR mirror 102 which is a lower semiconductor multilayer mirror, buffer layer 103, n-type contact layer 104, active layer 105 having a multiple quantum well structure, current confinement portion 107a and current confinement portion 107a located on the outer periphery A current confinement layer 107 having a current injection portion 107b located at the center of the first electrode, a p-type spacer layer 109, and a p ⁺ -type contact layer 111 are sequentially stacked. The active layer 105 to the p ⁺ -type contact layer 111 constitute a cylindrical mesa post 110. The mesa post 110 is formed on the n-type contact layer 104.

The substrate 101 is made of undoped GaAs. The lower DBR mirror 102 is composed of 34 pairs of GaAs / Al _0.9 Ga _0.1 As layers. The buffer layer 103 is made of undoped GaAs. The n-type contact layer 104 is made of n-type GaAs. The active layer 105 has a structure in which an InGaAs well layer having 3 layers and a GaAs barrier layer having 4 layers are alternately stacked, and the lowermost GaAs barrier layer also functions as an n-type cladding layer. To do. As for the current confinement layer 107, the current confinement portion 107a is made of Al ₂ O ₃ and the current injection portion 107b has a diameter of 6 to 15 μm and is made of AlAs. The p-type spacer layer 109 and the p ⁺ -type contact layer 111 are made of p-type and p ⁺ -type GaAs doped with carbon, respectively. The acceptor or donor concentration (dopant concentration) of each p-type or n-type layer is, for example, about 1 × 10 ¹⁸ cm ⁻³ smaller than 2 × 10 ¹⁹ cm ⁻³ , and the acceptor concentration (dopant concentration) of the p ⁺ -type layer. ) Is, for example, 2 × 10 ¹⁹ cm ⁻³ . The refractive index of each semiconductor layer made of GaAs is about 3.45. On the p ⁺ -type contact layer 111, a ring-shaped (annular) p-side annular electrode 113 is provided. The outer diameter of the p-side annular electrode 113 is, for example, 30 μm, and the inner diameter of the opening 113a is, for example, 10 to 20 μm. The p-side annular electrode 113 is made of, for example, Pt / Au (Au and Pt below it).

In addition, a disc-shaped phase adjustment layer 114 made of silicon nitride (SiN _x ) is formed in the opening 113 a of the p-side annular electrode 113. This phase adjustment layer 114 is for adjusting the phase. A portion from the upper surface of the phase adjustment layer 114 to the bottom surface of the buffer layer 103 constitutes the resonator 130.

  The n-type contact layer 104 extends radially outward from the lower portion of the mesa post 130, and a semi-annular n-side electrode 117 made of, for example, AuGeNi / Au (Au and AuGeNi below) is formed on the surface thereof. ing. For example, the n-side electrode 117 has an outer diameter of 80 μm and an inner diameter of 40 μm.

A passivation film 123 is formed on the entire surface to cover the mesa post 130, the p-side annular electrode 113, the phase adjustment layer 114, the n-type contact layer 104, the n-side electrode 117, and the buffer layer 103 for surface protection. Yes. The passivation film 123 is composed of a lower SiO ₂ film 121 and an upper SiN _x film 122.

  At the base 131 portion of the mesa post 130, the passivation film 123 is bent and provided. A metal film 133 is provided on the passivation film 123 covering the base portion 131 of the mesa post 130 so as to cover the base portion 131 of the mesa post 130 over the entire periphery of the base portion 131 of the mesa post 130 via the passivation film 123. The metal film 133 is composed of an upper layer moisture-resistant metal film 133a and a lower layer adhesion improving metal film 133b. The moisture-resistant metal film 133a is composed of a two-layer film of an Au film, an Au film and a Pt film below the Au film, or a two-layer film of an Au film and a Mo film below the Au film. The adhesion improving metal film 133b is made of Ti, Cr, or Pd.

  When forming the passivation film 123, the reaction gas hardly flows around the base 131 portion of the mesa post 130, and the film thickness tends to be thin or the film quality tends to be deteriorated. Tend to. In the present embodiment, since the moisture-resistant metal film 133a is provided on the passivation film 123 covering the base 131 of the mesa post 130 so as to cover the base 131 of the mesa post 130 via the passivation film 123. Even if the thickness of the passivation film 123 covering the base 131 is thin or the film quality is poor, the intrusion of moisture can be effectively prevented or suppressed. As a result, it is possible to effectively prevent or suppress deterioration of the current confinement portion 107a due to the penetration of moisture.

  Further, an n-side lead electrode 118 made of Au is formed so as to come into contact with the n-side electrode 117 via an opening 141 formed in the passivation film 123. On the other hand, a p-side lead electrode 119 made of Au is also formed so as to come into contact with the p-side annular electrode 113 through an opening 142 formed in the passivation film 123. The n-side electrode 117 and the p-side annular electrode 113 are connected to the electrode pads 152 and 151 by the n-side extraction electrode 118 and the p-side extraction electrode 119, respectively. In the present embodiment, the p-side lead electrode 119 and the metal film 133 are electrically connected.

Further, a dielectric multilayer film 128 is formed on the entire surface so as to cover the passivation film 123, the metal film 133, the n-side extraction electrode 118, and the p-side extraction electrode 119. The dielectric multilayer film 128 is composed of, for example, 9 to 11 pairs of SiN _x / SiO ₂ . The passivation film 123 and the dielectric multilayer film 128 constitute an upper DBR mirror 116 that is an upper multilayer film reflecting mirror. The upper DBR mirror 116 is composed of, for example, 10-12 pairs of SiN _x / SiO ₂ . The upper DBR mirror 120 also functions as a passivation film.

The passivation film 123 also serves as a part of the upper DBR mirror 120. Therefore, the lower layer of SiO ₂ film 121 of the passivation film 123 also serves as a bottom layer of SiO ₂ film of the upper DBR mirror 120. _Therefore, the upper DBR mirror 120 made of SiN x / SiO _2, the bottom layer is a SiO ₂ film 121 of the passivation film 123, on which, provided the SiN _x film 122, on which a SiO ₂ SiN _x is alternately stacked, and the top layer is SiN _x .

  The upper DBR mirror 120 has a bent portion where a step is formed. These portions have uneven shapes formed by the presence of the mesa post 110, the metal film 133, the p-side annular electrode 113, the phase adjustment layer 114, the n-type contact layer 104, the n-side electrode 117, the buffer layer 103, and the like. It is formed by reflecting.

  A metal film 135 is provided so as to cover these bent portions where the steps are formed. The metal film 135 includes an upper layer moisture-resistant metal film 135a and a lower layer adhesion improving metal film 135b. The moisture-resistant metal film 135a is made of an Au film, a two-layer film of Pt / Au (Au film and an underlying Pt film), or a two-layer film of Mo / Au (Au film and an underlying Mo film). Yes. The adhesion improving metal film 135b is made of Ti, Cr, or Pd.

  As described above, the upper DBR mirror 120 also functions as a passivation film, but the mesa post 110, the metal film 133, the p-side annular electrode 113, the phase adjustment layer 114, the n-type contact layer 104, the n-side electrode 117, and the buffer layer. In the concavo-convex shape portion formed by the presence of 103 etc., the reactive gas is difficult to flow around when forming the dielectric multilayer film 128, and the film thickness tends to be thin or the film quality tends to be poor. Moisture tends to enter from such areas. In the present embodiment, the moisture-resistant metal film 135a is provided so as to cover the bent and stepped portion formed in the upper DBR mirror 120 reflecting such an uneven shape. Even if the film is bent and the thickness of the portion where the step is formed is thin or the film quality is poor, the intrusion of moisture can be effectively prevented or suppressed.

In addition, as shown in FIG. 1, openings 153 and 154 are provided in the upper DBR mirror 120 to expose the electrode pads 151 and 152. The electrode pads 151 and 152 are connected to an external current supply circuit (not shown). The surface-emitting type semiconductor laser device 100 is connected to an n-side electrode 117 and a p-side annular electrode 113 from an external current supply circuit (not shown) via an n-side extraction electrode 118 and a p-side extraction electrode 119, respectively. When a voltage is applied to and current is injected, the current mainly flows through the p ⁺ -type contact layer 111 having a low resistance, and the current path is confined in the current injection portion 107b by the current confinement layer 107, thereby increasing the current density. It is supplied to the active layer 105. As a result, the active layer 105 is carrier-injected and emits spontaneous emission light. Of the spontaneous emission light, light having a wavelength λ which is a laser oscillation wavelength forms a standing wave in the resonator 130 between the lower DBR mirror 102 and the upper DBR mirror 120 and is amplified by the active layer 105. When the injection current becomes equal to or greater than the threshold value, the light that forms the standing wave oscillates, and the 1060 nm band laser light is output from the opening 113 a of the p-side annular electrode 113.

  Next, a method for manufacturing the surface-emitting type semiconductor laser device 100 of the present embodiment will be described.

First, the lower DBR mirror 102, the buffer layer 103, the n-type contact layer 104, the active layer 105, the oxidized layer made of AlAs, the p-type spacer layer 109, and the p ⁺ -type contact layer 111 are sequentially formed on the substrate 101 by the epitaxial growth method. Then, a disk-like phase adjusting layer 114 made of SiN _x is selectively formed on the p ⁺ -type contact layer 111 by a plasma CVD (Chemical Vapor Deposition) method and a photolithography technique. The optical thickness of the phase adjustment layer 114 is about λ / 4.

Next, a p-side annular electrode 113 made of a Ti / Pt layer (Pt and Ti underneath) is formed on the p ⁺ type contact layer 111 around the dielectric layer 114 by using a lift-off method.

  Next, using the p-side annular electrode 113 as a metal mask, the semiconductor layer is etched to a depth reaching the n-type contact layer 104 using an acid etching solution or the like to form a cylindrical mesa post 110, and another mask. Then, the n-type contact layer 104 is etched to a depth reaching the buffer layer 103.

Next, heat treatment is performed in a steam atmosphere to selectively oxidize a layer corresponding to the current confinement layer 107 from the outer peripheral side of the mesa post 110. At this time, a chemical reaction of 2AlAs + 3H ₂ O → Al ₂ O ₃ + 2AsH ₃ occurs in the outer peripheral portion of the layer corresponding to the current confinement layer 107, and the current confinement portion 107a is formed. Since the chemical reaction proceeds uniformly from the outer peripheral side of the layer corresponding to the current confinement layer 107, the current injection portion 107b made of AlAs is formed at the center. Here, the heat treatment time or the like is adjusted so that the current injection portion 107b has a diameter of 6 to 15 μm. Since the current injection portion 107b is formed in this way, the center of the mesa post 130, the center of the current injection portion 107b, and the center of the opening 113a of the p-side annular electrode 113 can be matched with high accuracy. As a result, the surface emitting semiconductor laser device 100 can be a multimode oscillation mode laser with good reproducibility in which the number of transverse modes during oscillation is stable.

Next, a semi-circular n-side electrode 117 is formed on the surface of the n-type contact layer 104 on the outer peripheral side of the mesa post 130. Next, a passivation film 121 made of SiO ₂ and a passivation film 122 made of SiN _x are formed on the entire surface by plasma CVD to form a passivation film 123.

  Next, a metal film 133 that covers the base 131 of the mesa post 110 via the passivation film 123 is formed on the passivation film 123 using a lift-off method.

  Next, openings 141 and 142 are formed in the passivation film 123 on the n-side electrode 117 and the p-side annular electrode 113, respectively, and the n-side lead electrode that contacts the n-side electrode 117 through these openings 141 and 142 is formed. 118 and a p-side lead electrode 119 in contact with the p-side annular electrode 113 are formed. In the present embodiment, since the p-side extraction electrode 119 and the metal film 133 are electrically connected, the p-side extraction electrode 119, the n-side extraction electrode 118, and the metal film 133 can be formed simultaneously. In that case, the p-side lead electrode 119 and the n-side lead electrode 118 are composed of a moisture-resistant metal film made of Au, Pt / Au or Mo / Au and an adhesion improving metal film made of Ti, Cr or Pd. You can also

Next, a film made of SiO ₂ and a film 122 made of SiN _x are sequentially formed on the entire surface by using a plasma CVD method, a dielectric multilayer film 128 is formed, and an upper DBR mirror 120 is formed.

  Next, the lift-off method is used to form the metal film 135 so as to cover the bent portion of the upper DBR mirror 120 where the step is formed.

  Next, the back surface of the substrate 101 is polished, and the thickness of the substrate 101 is adjusted to, for example, 150 μm. Thereafter, element isolation is performed to complete the surface emitting semiconductor laser element 100.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, no dielectric film is provided between the p-side extraction electrode 119 and the metal film 133, and the p-side extraction electrode 119 and the metal film 133 are electrically connected. However, in this embodiment, the SiO ₂ film 124 and the SiN _x film 125 which are part of the upper DBR mirror 120 are provided between the p-side extraction electrode 119 and the metal film 133, and the p-side The extraction electrode 119 and the metal film 133 are different from the first embodiment in that they are not electrically connected, but the other points are the same.

In the present embodiment, the SiO ₂ film 124 covering the passivation film 123 and the metal film 133 and the SiN _x film 125 are formed over the entire surface by plasma CVD.

Next, openings 141 and 142 are formed in the passivation film 123, the SiO ₂ film 124, and the SiN _x film 125 on the n-side electrode 117 and the p-side annular electrode 113, respectively, and the openings 141 and 142 are passed through these openings 141 and 142, respectively. An n-side extraction electrode 118 that contacts the n-side electrode 117 and a p-side extraction electrode 119 that contacts the p-side annular electrode 113 are formed.

Thereafter, a dielectric multilayer film 127 is formed on the entire surface so as to cover the SiN _x film 125, the n-side extraction electrode 118, and the p-side extraction electrode 119. The dielectric multilayer film 127 is composed of, for example, 8 to 10 pairs of SiN _x / SiO ₂ . The passivation film 123, the SiO ₂ film 124, the SiN _x film 125, and the dielectric multilayer film 127 constitute the upper DBR mirror 120 that is an upper multilayer film reflecting mirror. The upper DBR mirror 120 also functions as a passivation film, and the SiO ₂ film 124 and the SiN _x film 125 are part of the upper DBR mirror 120 and also function as a passivation film.

  Any film that is a part of the upper DBR mirror 120 may be provided between the p-side extraction electrode 119 and the metal film 133.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. In the second embodiment, the p-side extraction electrode 119 is provided on the metal film 133 via the SiO ₂ film 124 and the SiN _x film 125. However, in this embodiment, the p-side extraction electrode 119 is formed on the p-side extraction electrode 119. The second embodiment differs from the second embodiment in that a metal film 133 is provided via a SiO ₂ film 124 and a SiN _x film 125, but the other points are the same.

  In this embodiment, after the passivation film 123 is formed, openings 141 and 142 are formed in the passivation film 123 on the n-side electrode 117 and the p-side annular electrode 113, respectively, and the openings 141 and 142 are interposed therebetween. Then, an n-side extraction electrode 118 that contacts the n-side electrode 117 and a p-side extraction electrode 119 that contacts the p-side annular electrode 113 are formed.

Thereafter, the SiO ₂ film 124 and the SiN _x film 125 are formed on the entire surface by plasma CVD so as to cover the passivation film 123, the n-side extraction electrode 118, and the p-side extraction electrode 119.

Next, a metal film 133 that covers the base 131 of the mesa post 110 via the passivation film 123, the SiO ₂ film 124, and the SiN _x film 125 is formed on the SiN _x film 125 using a lift-off method.

Thereafter, a dielectric multilayer film 127 is formed on the entire surface so as to cover the film 125 made of SiN _x and the metal film 133. The dielectric multilayer film 127 is composed of, for example, 8 to 10 pairs of SiN _x / SiO ₂ . The passivation film 123, the film 124 made of SiO ₂ , the film 125 made of SiN _x , and the dielectric multilayer film 127 constitute the upper DBR mirror 120 that is an upper multilayer film reflecting mirror. The upper DBR mirror 120 also functions as a passivation film, and the SiO ₂ film 124 and the SiN _x film 125 are part of the upper DBR mirror 120 and also function as a passivation film.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the first embodiment, the metal film 133 is provided on the passivation film 123 that covers the base 131 of the mesa post 130 so as to further cover the base 131 of the mesa post 130 via the passivation film 123. Then, a moisture-resistant metal film 133 that covers the base 131 of the mesa post 130 over the entire circumference of the base 131 of the mesa post 130 is provided, and the base 131 of the mesa post 130 is covered on the metal film 133 via the metal film 133. Although the point which provides the passivation film 123 differs from 1st Embodiment, the other point is the same.

  Since the moisture-resistant metal film 133 in this embodiment is formed directly over a semiconductor, a high-resistance material is used. In consideration of the difference in thermal expansion coefficient with the semiconductor layer and the fact that it does not react with the semiconductor layer, an alloy film of Ni, Cr and Al or a silicide film of Ni and Cr can be preferably used for the metal film 133.

  In the present embodiment, a metal film 133 that covers the base 131 of the mesa post 130 is provided by a lift-off method, and a passivation film 123 is formed over the entire surface of the metal film 133.

In the first to fourth embodiments described above, the passivation film 123 is composed of the lower SiO ₂ film 121 and the upper SiN _x film 122. However, any one of these layers may be used.

(Fifth embodiment)
A fifth preferred embodiment of the present invention will be described with reference to FIGS. 6 and 7, the semiconductor laser device of the present embodiment is a surface emitting semiconductor laser device. The surface emitting semiconductor laser device 200 is formed on a substrate 201 and the substrate 201. A lower DBR mirror 202, which is a lower semiconductor multilayer reflector, a lower cladding layer 203 formed on the lower DBR mirror 202, an active layer 204 formed on the lower cladding layer 203 and having a quantum well structure, and an active layer An upper clad layer 205 formed on 204 and an upper DBR mirror 206 which is an upper semiconductor multilayer film reflecting mirror formed on the upper clad layer 205 are provided. The lower clad layer 203 to the upper DBR mirror 206 constitute a cylindrical mesa post 210. The mesa post 210 is formed on the lower DBR mirror 202. The lower cladding layer 203, the active layer 204 and the upper cladding layer 205 constitute a resonator 220. An n-side electrode 230 is provided on the lower surface of the substrate 201.

  One layer of the upper DBR mirror 206 on the side closer to the active layer 204 is a current confinement layer 207 having a current confinement portion 208 located on the outer periphery and a current injection portion 209 located in the center of the current confinement portion 208.

The substrate 201 is made of n-GaAs. The lower DBR mirror 202 has an n-Al _0.9 Ga _0.1 As / n-Al _0.2 Ga ₀ layer with a thickness of λ / 4n (λ is an oscillation wavelength and n is a refractive index). _.8 35 pairs of As. The lower cladding layer 203 _is composed of _n-Al 0.4 _{Ga 0.6} As. The active layer 204 has a quantum well structure including a GaAs well layer and an Al _0.2 Ga _0.8 As barrier layer. The upper clad layer 205 is made of p-Al _0.4 Ga _0.6 As.

The upper DBR mirror 206 has p-Al _0.9 Ga _0.1 As / p-Al _0.2 Ga _{0.8 having} a thickness of each layer of λ / 4n (λ is an oscillation wavelength and n is a refractive index). It consists of 25 pairs of As. One layer of the upper DBR mirror 206 closer to the active layer 204 is formed of an AlAs layer instead of the Al _0.9 Ga _0.1 As layer, and AlAs in the surrounding region is selectively oxidized, and Al ₂ O ₃ The current confinement portion 208 is made of The current injection portion 209 located at the center of the current confinement portion 208 is made of AlAs.

  The diameter of the mesa post 210 is about 30 μm. An annular p-side electrode 231 is provided on the upper surface of the upper DBR mirror 206 that is the upper surface of the mesa post 210. The p-side electrode 231 is made of, for example, Ti / Pt. The n-side electrode 230 on the lower surface of the substrate 201 is made of, for example, AuGeNi / Au.

A passivation film 222 is provided on the entire surface covering the p-side electrode 231, the upper surface of the upper DBR mirror 206 that is the upper surface of the mesa post 210, the side surface of the mesa post 210, and the upper surface of the lower DBR mirror 202. The passivation film 222 is composed of a lower SiO ₂ film and an upper SiN _x film. The passivation film 222 may be composed of a SiO ₂ film or a SiN _x film.

  In the base 221 portion of the mesa post 210, the passivation film 222 is bent and provided. A metal film 223 is further provided on the passivation film 222 that covers the base 221 of the mesa post 210 so as to cover the base 221 of the mesa post 210 over the entire periphery of the base 221 of the mesa post 210 via the passivation film 222. The metal film 223 is composed of an upper moisture-resistant metal film 223a and a lower adhesion metal film 223b. The moisture-resistant metal film 223a is composed of a two-layer film of an Au film, an Au film and a Pt film below the Au film, or a two-layer film of an Au film and a Mo film therebelow. The adhesion improving metal film 223b is made of Ti, Cr, or Pd.

  When forming the passivation film 222, the reaction gas hardly flows around the base portion 221 of the mesa post 210, and the film thickness tends to be thin or the film quality tends to deteriorate. Tend to. In the present embodiment, the moisture-resistant metal film 223a is provided on the passivation film 222 that covers the base portion 221 of the mesa post 210 so as to further cover the base portion 221 of the mesa post 210 via the passivation film 222. Even if the thickness of the passivation film 222 covering the base portion 221 is reduced or the film quality is deteriorated, the intrusion of moisture can be effectively prevented or suppressed.

  The passivation film 222 on the upper surface of the mesa post 210 is provided with an opening 233 to expose the inner portion of the annular p-side electrode 231 and the upper surface of the upper DBR mirror 206 that is the upper surface of the mesa post 210.

  A polyimide layer 240 is formed on the entire surface so as to cover the passivation film 222 and the metal film 223. The mesa post 210 has a structure in which the periphery of the mesa post 210 is embedded with a polyimide layer 240, and is flattened. A ring-shaped p-side lead electrode 232 and an electrode pad 234 connected to the p-side lead electrode 232 are provided on the polyimide layer 240. The polyimide layer 240 does not have moisture resistance and allows moisture to permeate. However, in this embodiment, since the passivation film 222 and the moisture-resistant metal film 223 are provided, entry of moisture can be effectively prevented or suppressed.

  Next, a method for manufacturing the surface emitting semiconductor laser element 200 of the present embodiment will be described.

  First, a lower DBR mirror 202, a lower cladding layer 203, an active layer 204, a lower cladding layer 205, and an upper DBR mirror 206 having an AlAs layer below the substrate 201 are sequentially stacked on the substrate 201 by an epitaxial growth method.

  Next, an annular p-side electrode 231 made of a Ti / Pt layer is formed on the upper DBR mirror 206 using a lift-off method.

  Next, using the p-side electrode 231 as a metal mask, the semiconductor layer is etched to a depth reaching the lower DBR mirror 202 using an acid etching solution or the like to form a cylindrical mesa post 210.

Next, heat treatment is performed in a water vapor atmosphere to selectively oxidize a layer corresponding to the current confinement layer 207 from the outer peripheral side of the mesa post 210. At this time, a chemical reaction of 2AlAs + 3H ₂ O → Al ₂ O ₃ + 2AsH ₃ occurs in the outer peripheral portion of the layer corresponding to the current confinement layer 207, and the current confinement portion 208 is formed. Since the chemical reaction proceeds uniformly from the outer peripheral side of the layer corresponding to the current confinement layer 107, a current injection portion 209 made of AlAs is formed at the center.

Next, a passivation film 222 is formed by forming a SiO ₂ film and a SiN _x film on the entire surface by using a plasma CVD method.

  Next, a metal film 223 that covers the base 221 of the mesa post 210 via the passivation film 222 is formed on the passivation film 222 by using a lift-off method.

Next, an opening 233 is provided in the passivation film 222. Next, a polyimide film 240 is provided. Next, a p-side lead electrode 232 and an electrode pad 234 are selectively formed on the polyimide film 240.

  Next, the lower surface of the substrate 201 is appropriately polished to adjust the substrate thickness to, for example, 200 μm, and then the n-side electrode 230 is formed on the lower surface of the substrate 201.

  Then, element isolation is performed, and the surface emitting semiconductor laser element 200 is completed.

In the first to fourth embodiments, the current confinement layer 107 includes the current confinement portion 107a made of Al ₂ O ₃ and the current injection portion 107b made of AlAs. In the fifth embodiment, the current confinement layer 107a The constriction layer 207 includes a current confinement portion 208 made of Al ₂ O ₃ and a current injection portion 209 made of AlAs. However, the current confinement layers 107 and 207 have a small amount of AlAs (for example, 2-3 mol of Al). The current injection portion may be formed of AlGaAs substituted with% Ga, and the current confinement portion may be formed of an oxide insulator obtained by oxidizing AlGaAs.

  Next, an example of a surface emitting laser array using a plurality of surface emitting semiconductor laser elements 100 and 200 according to a preferred embodiment of the present invention will be described with reference to FIGS. As an example, as shown in FIG. 8, a surface emitting laser array chip 700 mounted on a known flat package 710 called CLCC (Ceramic Leaded Chip Carrier) is used. In the figure, the connection between the metal caster (electrode) 714 and the surface emitting laser array chip 700 is omitted for the sake of simplicity. As shown in FIG. 9, the surface emitting laser array chip 700 is provided with a plurality of surface emitting semiconductor laser elements 100 (200) provided in the central portion and a plurality of the element portions 702. A plurality of electrode pads 706 connected (not shown) to the light emitting portion. Furthermore, each electrode pad 706 is connected to a metal caster 714 of the flat package 712 (not shown). Each light emitting unit is controlled to emit light by an external control circuit (not shown) connected to the flat package 712, and emits laser light having a predetermined wavelength.

  Next, an example in which the surface emitting semiconductor laser elements 100 and 200 according to the preferred embodiments of the present invention are applied to an optical apparatus will be described with reference to the drawings. FIG. 10 is a schematic longitudinal sectional view showing a configuration when the surface emitting semiconductor laser elements 100 and 200 according to the preferred embodiment of the present invention are applied to a package of the light emitting elements. The surface emitting laser package 300 includes a surface emitting laser module including surface emitting semiconductor laser elements 100 and 200, a substrate 304 and an electrode 306, a lens 316, a housing 310, an optical fiber mount 312, and an optical fiber 314. The electrode 306 is electrically connected to an external control circuit (not shown), and the light emission of the surface emitting laser package is controlled. Laser light emitted from the surface emitting semiconductor laser elements 100 and 200 is collected by a lens 316 and coupled to an optical fiber 314.

  FIG. 11 is a schematic longitudinal sectional view showing a configuration when the surface emitting semiconductor laser elements 100 and 200 according to the preferred embodiment of the present invention are applied to a pickup of a writing / reading device for an optical storage medium. The pickup 350 includes a surface emitting laser module including a surface emitting semiconductor laser element 100, 200, a substrate 354, an electrode 356, a driving IC 358, and a resin 360 that seals these elements, a lens 376, a half mirror 370, a diffraction grating. 374, an optical sensor 380, and an optical storage medium 372. The exit surface of the resin 360 is processed into a convex shape to constitute a lens 362. The electrode 3546 is electrically connected to an external control circuit (not shown), and the light emission of the laser pickup is controlled. Laser light emitted from the surface emitting semiconductor laser elements 100 and 200 is converted into parallel light by the lens 362, reflected by the half mirror 370, collected by the lens 376, and collected at a predetermined position of the optical storage medium 372. Is done. Further, the light reflected by the optical medium is incident on the optical sensor 380. Here, the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array having a plurality of surface emitting semiconductor laser elements 100 and 200 according to a preferred embodiment of the present invention is used as a light emitting element package for communication or an optical disc. However, the present invention is not limited to this, but it is not limited to this, such as surveying instruments, laser pointers, optical mice, printers, light sources for scanning exposure of photoresist, light sources for laser pumping, light sources for processing fiber lasers, etc. It can also be used as an optical instrument.

  FIG. 12 is a schematic configuration diagram of an optical transceiver module to which the surface emitting semiconductor laser elements 100 and 200 according to the preferred embodiment of the present invention are applied. As shown in FIG. 12, the optical transceiver module 400 includes a holding member 402, an optical waveguide (optical fiber) 412, a spacer 410 for positioning the optical waveguide (optical fiber) 412 on the holding member 402, and an optical waveguide (optical fiber). ) Surface-emitting semiconductor laser elements 100 and 200 that transmit optical signals via 412 or a surface-emitting laser element array that includes a plurality of surface-emitting semiconductor laser elements 100 and 200, and a light-receiving element 404 that receives optical signals, and surface-emitting light It comprises a drive circuit 406 that controls the light emission state of the type semiconductor laser elements 100 and 200 or the surface emitting laser element array, and an amplification circuit 408 that amplifies the signal received by the light receiving element 404. The surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array is controlled to emit light via a drive circuit 406 by a control signal from an external control unit (not shown), and the signal received by the light receiving element 404 is amplified. It is transmitted to the control unit via the circuit 408. In order to avoid complication, the wire bonding of the drive circuit 406 and the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array / amplifier circuit 408 and the light receiving element 404 is omitted.

  13 to 15 are schematic configuration diagrams of an optical coupling portion between the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array in FIG. 12 and the optical waveguide 412. The substrate 500 and the surface emitting semiconductor laser element are shown in FIG. 100, 200 or the surface emitting laser element array and the optical waveguide 412 are common in FIGS. In FIG. 13, the end surface of the waveguide 412 is processed so as to be inclined at approximately 45 degrees with respect to the optical axis. Further, this inclined surface is used as a reflective surface 504 and is subjected to mirror surface processing such as coating of a reflective film. Light emitted from the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array is incident on the waveguide from the lower surface of the waveguide 412, is reflected by the inclined surface 504, and propagates through the optical waveguide 412. In FIG. 14, a mirror assembly 506 having a reflection surface 504 provided inside is provided on the side surface of the optical waveguide 412 on the surface-emitting semiconductor laser device 100, 200 or the surface-emitting laser device array. The light emitted from the laser elements 100 and 200 or the surface emitting laser element array is incident from the lower surface of the mirror assembly 506, reflected by the reflecting surface 504, and the light emitted from the mirror assembly 506 is coupled to the optical waveguide 412 to be optical. Propagates through the waveguide 412. A microlens (array) may be provided on the entrance surface and / or the exit surface of the mirror assembly 506. In FIG. 15, the optical fiber 412 is disposed in the connector housing 512, and the end portion of the curved portion 514 of the optical fiber core wire is disposed so as to face the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array. Then, light emitted from the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array is coupled to the optical fiber 412.

  Next, an example in which the surface emitting laser element 100, 200 or the surface emitting laser element array having a plurality of surface emitting semiconductor laser elements 100, 200 according to a preferred embodiment of the present invention is applied to a communication system will be described. FIG. 16 shows a configuration example of a wavelength multiplexing transmission system using the surface emitting semiconductor laser elements 100 and 200 or the surface emitting laser element array. 16 includes a computer, a board or chip 602, a communication control circuit (CPU, MPU, optical-electrical conversion circuit, electrical-optical conversion circuit, wavelength control circuit) 604, and surface emitting semiconductor laser elements 100, 200. A plurality of surface emitting laser element arrays 606, a light receiving element integrated unit 608, a multiplexer 610, a duplexer 612, an electrical wiring 616, optical fibers 617 and 618, a communication target network, a PC, a board, a chip, and the like 614. . In the wavelength division multiplex transmission system of FIG. 16, a surface emitting laser array 606 is configured by arranging a plurality of surface emitting laser elements having different oscillation wavelengths, and each oscillation light from each surface emitting laser element of the surface emitting laser array 606 is combined. It is configured to be coupled to one optical fiber through a waver. In such a configuration, a large amount of signal can be transmitted with high throughput with a single fiber. As described above, the surface emitting laser array according to the preferred embodiment of the present invention is stable in mode and stable in each oscillation wavelength. It becomes possible. In this embodiment, the output optical fiber or the input optical fiber from each surface emitting laser array 606 or the light receiving element integrated unit 608 is coupled to one optical fiber using the multiplexer 610 or the demultiplexer 612. However, depending on the application, an output optical fiber or an input optical fiber can be directly connected to a communication target network, PC, board, chip, or the like 614 to form a parallel transmission system. In this case, since the surface emitting laser array according to the preferred embodiment of the present invention has a stable mode and each wavelength is stable, a highly reliable parallel transmission system having a plurality of light sources can be constructed. It becomes easy.

  While various typical embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Accordingly, the scope of the invention is limited only by the following claims.

100, 200 Surface emitting semiconductor laser device 101, 201 Substrate 102, 202 Lower DBR mirror 103 Buffer layer 104 N-type contact layer 105, 204 Active layer 107, 207 Current confinement layer 107a, 208 Current confinement portion 107b, 209 Current injection portion 109 p-type spacer layer 110, 210 mesa post 111 p ⁺ -type contact layer 113 p-side annular electrode 113a opening 114 phase adjusting layer 117, 230 n-side electrode 118 n-side extraction electrode 119, 232 p-side extraction electrode 120, 206 upper part DBR mirror 121, 124 SiO ₂ film 122, 125 SiN _x film 123, 222 Passivation film 127, 128 Dielectric multilayer film 130, 220 Resonator 131, 221 Base 133, 223, 135 Metal film 133a, 135a 223a Moisture resistant metal film 133b, 135b, 223b Adhesion improving metal film 141, 142 Opening 151, 152, 234 Electrode pad 153, 154 Opening 203 Lower clad layer 205 Upper clad layer 231 P-side electrode 233 Opening 240 Polyimide layer

Claims (29)

A substrate,
A first electrode;
A second electrode;
A first reflector;
A second reflector;
A resonator formed between the first reflecting mirror and the second reflecting mirror, which narrows a current path between an active layer, the first electrode, and the second electrode. The resonator comprising a layer;
A protrusion formed on one principal surface of the substrate, the protrusion including the current confinement layer;
A passivation film covering the convex portion and one main surface of the substrate;
A semiconductor laser device comprising: a moisture-resistant metal film that covers a base portion of the convex portion directly or via the passivation film.   2. The semiconductor laser according to claim 1, wherein a base portion of the convex portion is covered with the passivation film, and further, the base portion is covered with the moisture-resistant metal film provided on the passivation film via the passivation film. element. An electrode pad;
A lead electrode for connecting the first electrode and the electrode pad;
3. The semiconductor laser device according to claim 2, wherein the first electrode is provided on an upper surface of the convex portion, and the extraction electrode and the moisture-resistant metal film are electrically connected. An electrode pad;
A lead electrode for connecting the first electrode and the electrode pad;
The first electrode is provided on an upper surface of the convex portion, and a second passivation film is provided between the extraction electrode and the moisture-resistant metal film, and the extraction electrode and the moisture-resistant metal are provided. 3. The semiconductor laser device according to claim 2, wherein the semiconductor laser device is not electrically connected to the film.   2. The semiconductor laser device according to claim 1, wherein a base portion of the convex portion is covered with the moisture-resistant metal and further covered with the passivation film provided on the moisture-resistant metal. A third passivation film covering the passivation film and the moisture-resistant metal;
6. The semiconductor laser device according to claim 1, further comprising: a second moisture-resistant metal film that covers a step portion of the third passivation film. A third passivation film covering the passivation film, the first electrode, the lead electrode and the moisture-resistant metal;
5. The semiconductor laser device according to claim 3, further comprising: a second moisture-resistant metal film that covers a step portion of the third passivation film. 6. A semiconductor layer provided on the one principal surface of the semiconductor substrate;
A second electrode pad;
A second lead electrode connecting the second electrode and the second electrode pad; and
The convex portion is provided on the semiconductor layer, the convex portion includes the active layer, and the second electrode is provided on the semiconductor layer so as to be separated from the convex portion,
8. The semiconductor laser device according to claim 7, wherein the third passivation film further covers the semiconductor layer, the second electrode, and the second extraction electrode.   The moisture-resistant metal film is any metal film selected from the group consisting of an Au film, a two-layer film of an Au film and an underlying Pt film, and a two-layer film of an Au film and an underlying Mo film. The semiconductor laser device according to claim 2.   10. The metal film for improving adhesion according to claim 2, further comprising a metal film for improving adhesion provided under the moisture-resistant metal film and improving adhesion between the moisture-resistant metal film and the passivation film. 11. Semiconductor laser device.   11. The semiconductor laser device according to claim 10, wherein the adhesion improving metal film is any metal film selected from the group consisting of Ti, Cr and Pd.   6. The semiconductor laser device according to claim 5, wherein the moisture-resistant metal film is an alloy film of Ni, Cr, and Al or a silicide film of Ni and Cr.   The second moisture-resistant metal film is any metal selected from the group consisting of an Au film, a two-layer film of an Au film and an underlying Pt film, and a two-layer film of an Au film and an underlying Mo film 7. The semiconductor laser device according to claim 6, wherein the semiconductor laser device is a film.   A second adhesion-improving metal film provided under the second moisture-resistant metal film to improve adhesion between the second moisture-resistant metal film and the third passivation film; The semiconductor laser device according to claim 6 or 13.   15. The semiconductor laser device according to claim 14, wherein the second adhesion improving metal film is any metal film selected from the group consisting of Ti, Cr, and Pd.   16. The semiconductor laser device according to claim 1, wherein the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the passivation film is a part of the dielectric multilayer film reflecting mirror.   5. The semiconductor laser element according to claim 4, wherein the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the second passivation film is a part of the dielectric multilayer film reflecting mirror.   8. The semiconductor laser device according to claim 6, wherein the first reflecting mirror is a dielectric multilayer film reflecting mirror, and the third passivation film is a part of the dielectric multilayer film reflecting mirror. The semiconductor laser device according to claim 16, wherein the dielectric multilayer film reflecting mirror is made of a plurality of pairs of SiO ₂ / SiN _x .   2. The current confinement layer includes an aluminum-containing compound semiconductor layer and an oxide insulator layer provided around the aluminum-containing compound semiconductor layer and obtained by oxidizing the aluminum-containing compound semiconductor layer. 20. A semiconductor laser device according to any one of items 19 to 19.   6. The semiconductor laser device according to claim 1, further comprising a planarizing dielectric film provided on the passivation film and the moisture-resistant metal. An electrode pad;
A lead electrode for connecting the first electrode and the electrode pad;
The semiconductor laser device according to claim 21, wherein the first electrode is provided on an upper surface of the convex portion, and the lead electrode and the electrode pad are provided on the planarizing dielectric film. A substrate,
A first electrode;
A second electrode;
A first reflector;
A second reflector;
A resonator formed between the first reflecting mirror and the second reflecting mirror, which narrows a current path between an active layer, the first electrode, and the second electrode. The resonator comprising a layer;
A protrusion formed on one principal surface of the substrate, the protrusion including the current confinement layer;
A passivation film covering the convex portion and one main surface of the substrate;
A semiconductor laser device comprising: a moisture-resistant metal film that covers a bent portion of the passivation film. An electrode pad;
A lead electrode for connecting the first electrode and the electrode pad;
The first electrode is provided on the upper surface of the convex portion,
24. The semiconductor laser device according to claim 23, wherein the passivation film further covers the first electrode and the electrode pad. A semiconductor layer provided on the one principal surface of the semiconductor substrate;
A second electrode pad;
A second lead electrode connecting the second electrode and the second electrode pad; and
The convex portion is provided on the semiconductor layer, the convex portion includes the active layer, and the second electrode is provided on the semiconductor layer so as to be separated from the convex portion,
25. The semiconductor laser device according to claim 24, wherein the passivation film further covers the semiconductor layer, the second electrode, and the second extraction electrode.   The first reflecting mirror is a dielectric multilayer film reflecting mirror, and the passivation film is the dielectric multilayer film reflecting mirror or a part of the dielectric multilayer film reflecting mirror. The semiconductor laser device described in 1.   A laser array comprising a plurality of the semiconductor laser elements according to claim 1.   An optical apparatus comprising the semiconductor laser element according to any one of claims 1 to 26.   A communication system comprising the semiconductor laser device according to any one of claims 1 to 26.

Images