JP2007294741A - Surface-emitting semiconductor laser, optical transmission module, and optical transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical resonance surface-emitting semiconductor laser that is excellent in high-frequency characteristics without causing deterioration in mechanical strength. <P>SOLUTION: A p-type upper DBR 107 (including an AlAs layer 106), an upper spacer layer 105, a multiple quantum well active layer 104, and a lower spacer layer 103 that are located under a wiring 113 and bonding pad 114 (-Z side) are removed by etching so as to be planarized after implanting polyimide 111. A permittivity of polyimide is a small value of about one-third of that of each semiconductor layer. Therefore, an insulating dielectric having a lower permittivity is thickly provided between the wiring 113/bonding pad 114 and an n-side ohmic electrode 115 so as to have a thickness of several μm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surface emitting semiconductor laser, an optical transmission module, and an optical transmission system. More specifically, the present invention includes a vertical cavity surface emitting semiconductor laser, an optical transmission module having the surface emitting semiconductor laser, and the optical transmission module. The present invention relates to an optical transmission system.

  In recent years, optical transmission technology has been developed not only for trunk transmission networks but also for LANs, optical access systems, home networks, and the like. As a light source for LAN and optical interconnection, a vertical cavity surface emitting laser (VCSEL) has been used. A VCSEL has lower power consumption than a conventional end facet type semiconductor laser, and does not require cleavage in the manufacturing process, and can be inspected in a wafer state, and thus is excellent in cost reduction.

  By the way, in this VCSEL, a part of a semiconductor layer having a high aluminum (Al) concentration in a stacked body in which a plurality of semiconductor layers are stacked is oxidized and insulated to form a current confinement structure. However, since the oxide layer is distorted by volume contraction, the bond between the oxide layer and the upper and lower semiconductor layers is weakened, and defects such as dislocations and cracks may occur. These defects can reduce the reliability of the VCSEL. Therefore, by forming grooves and holes in a part of the stacked body and partially combining the region (element region) that becomes the VCSEL and the surrounding region (external region), surface emission that prevents the occurrence of defects Lasers have been proposed (see, for example, Patent Document 1 and Patent Document 2).

  In the surface emitting laser disclosed in Patent Document 1, a substantially cylindrical mesa region and an external region are connected by a bridge girder provided in a groove. An upper electrode is provided on the surface of the mesa region, and the upper electrode is connected to a bonding pad provided in the external region through the bridge beam. The bonding pad and the wiring connecting the bonding pad and the upper electrode are formed on the surface of the semiconductor layer where no groove is provided. An insulating film is provided between the bonding pad and wiring and the lower electrode. However, since the insulating film thickness is thin, the capacity is increased and the high frequency characteristics of the element are deteriorated.

  In the surface emitting laser disclosed in Patent Document 2, a C-type trench is formed. The upper electrode, wiring, and bonding pad are formed on the surface of the semiconductor layer where no trench is formed. In the surface emitting laser disclosed in Patent Document 2, in order to reduce the parasitic capacitance of the bonding pad, proton ions are implanted into the semiconductor layer located under the bonding pad. However, since the dielectric constant of the semiconductor layer is relatively large, the parasitic capacitance is not sufficiently reduced.

  Patent Document 3 discloses a configuration of a surface emitting semiconductor laser element in FIG. In this surface emitting semiconductor laser element, one groove is formed, and the AlAs layer is selectively oxidized therefrom. In this case, the entire periphery of the element portion is surrounded by the groove, and the region where the distortion due to oxidation in the AlAs layer is not generated is only the non-oxidized current injection portion. Since the current injection portion has a small area, the mechanical strength of the element portion becomes weak. Further, since the element portion and the peripheral portion are not connected, the heat dissipation path is reduced, which causes deterioration of the element due to heat generation.

JP-A-2005-45107 JP 2002-94180 A JP 2003-133303 A

  The present invention has been made under such circumstances, and a first object thereof is to provide a vertical cavity surface emitting semiconductor laser having excellent high frequency characteristics without causing a decrease in mechanical strength. .

  A second object of the present invention is to provide an optical transmission module that enables optical transmission at high speed.

  A third object of the present invention is to provide an optical transmission system capable of performing optical transmission at high speed.

  According to a first aspect of the present invention, a lower multilayer reflector, a resonator structure including an active layer, and an upper multilayer reflector are laminated on a substrate, and the lower multilayer reflector and the resonator structure are stacked. And a vertical resonance type in which an upper electrode and a bonding pad are formed on the upper surface of a laminate having an oxidized layer containing aluminum in any of the upper multilayer mirrors, and the upper electrode is connected to the bonding pad by wiring In the surface emitting semiconductor laser, the stacked body is etched to remove at least the oxidized layer located below the wiring and the bonding pad to form a recess, and an insulating dielectric is formed in the recess. A surface emitting semiconductor laser characterized by being embedded.

  According to this, in the laminated body, at least the oxidized layer located below the wiring and the bonding pad is removed by etching to form a recess, and an insulating dielectric is embedded in the recess. Therefore, as a result, it is possible to suppress a decrease in high-frequency characteristics without causing a decrease in mechanical strength.

  According to a second aspect of the present invention, there is provided an optical transmission module for generating an optical signal corresponding to an input electric signal, the surface emitting semiconductor laser of the present invention; An optical transmission module comprising: a driving device that is driven according to an electrical signal.

  According to this, since the surface emitting semiconductor laser of the present invention having excellent high frequency characteristics is provided, high-speed optical transmission can be achieved.

  According to a third aspect of the present invention, there is provided an optical transmission module of the present invention that generates an optical signal according to an input electric signal; an optical transmission means that transmits the optical signal; An optical transmission system comprising: a conversion device that converts an optical signal into an electrical signal.

  According to this, since the optical transmission module of the present invention is provided, it is possible to perform optical transmission at high speed.

<< First Embodiment >>
A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic configuration of a vertical cavity surface emitting semiconductor laser (VCSEL) 100 according to the first embodiment of the present invention. In FIG. 1, the left-right direction of the paper surface is the X-axis direction, the vertical direction of the paper surface is the Y-axis direction, and the direction perpendicular to the paper surface is the Z-axis direction. FIG. 2 shows an AA cross section of the VCSEL 100 of FIG.

  In the VCSEL 100, as shown in FIG. 2, an n-type lower distributed Bragg reflector (hereinafter also referred to as “n-type lower DBR”) 102 and a lower spacer layer 103 are formed on an n-type GaAs substrate 101 (+ Z side). , Semiconductor layers such as a multiple quantum well (MQW) active layer 104, an upper spacer layer 105, and a p-type upper distributed Bragg reflector (hereinafter also referred to as “p-type upper DBR”) 107 are sequentially stacked by epitaxial growth. . Hereinafter, a structure in which a plurality of semiconductor layers are stacked in this way is also referred to as a “stacked body” for convenience.

In the n-type lower DBR 102, a high refractive index layer made of n-type Al _0.2 Ga _0.8 As and a low refractive index layer made of n-type Al _0.9 Ga _0.1 As each have an oscillation wavelength ( 850 nm) with a thickness that becomes a quarter of the optical length.

The lower spacer layer 103 is a layer made of Al _0.2 Ga _0.8 As.

The multiple quantum well active layer 104 is a layer made of GaAs / Al _0.4 Ga _0.6 As.

The upper spacer layer 105 is a layer made of Al _0.2 Ga _0.8 As.

The p-type upper DBR 107 has a high refractive index layer made of p-type Al _0.2 Ga _0.8 As and a low refractive index layer made of p-type Al _0.9 Ga _0.1 As each having an oscillation wavelength. The layers are alternately stacked with a thickness that provides a quarter of the optical length. The p-type upper DBR 107 has an AlAs layer 106 in the vicinity of the boundary with the upper spacer layer 105.

  A region sandwiched between the n-type lower DBR 102 and the p-type upper DBR 107 has a thickness that is an optical length corresponding to one wavelength of the oscillation wavelength, and constitutes a so-called resonator structure.

  An n-side ohmic electrode 115 is formed on the back surface (the surface on the −Z side) of the n-type GaAs substrate 101.

  As shown in FIG. 1, four grooves (108a, 108b, 108c, and 108d) are formed in the laminated body by etching. In particular, the groove 108 d is formed in a size larger than the wiring 113 and the bonding pad 114. Each groove has a depth at least across the AlAs layer 106. Here, as an example, the bottom surface of each groove reaches the n-type lower DBR 102. That is, each groove is formed by removing the p-type upper DBR 107 and the resonator structure.

  The AlAs layer 106 is selectively oxidized from the inner side surface of the groove to form an Al oxide layer 109 (see FIG. 2). In the region surrounded by the four grooves, a non-oxidized region 117 surrounded by the Al oxide layer 109 is formed, and current is concentrated in the non-oxidized region 117. In addition, the inner side surface of each groove is covered with an insulating layer 110.

  In the region surrounded by the four grooves, the p-side ohmic electrode 112 is formed on the surface of the p-type upper DBR 107 except for the light emitting portion 116.

  In the groove 108d, polyimide 111 is embedded to flatten the groove. A bonding pad 114 is formed on the polyimide 111. The bonding pad 114 is connected to the p-side ohmic electrode 112 through the wiring 113.

  By flowing a forward current between the p-side ohmic electrode 112 and the n-side ohmic electrode 115, carriers are injected into the multiple quantum well active layer 104 to emit light. At this time, the current is confined to the central non-oxidized region 117 by the Al oxide layer 109. The light emitted from the multiple quantum well active layer 104 resonates at the resonator structure and is emitted in the + Z direction as laser light having a wavelength of 850 nm.

  That is, the region surrounded by the four grooves in the stacked body is a portion contributing to laser oscillation (hereinafter referred to as “element portion”).

  As described above, according to the VCSEL 100 according to the first embodiment, the element portion and the outer region (hereinafter referred to as “external region”) are connected by a so-called epi (crystal growth layer). In the Al oxide layer 109, the selectively oxidized portion and the non-oxidized portion are connected as a whole. Thereby, the mechanical strength of the laminate is increased, thereby reducing the influence of the stress generated in the Al oxide layer 109, and the generation of defects from the Al oxide layer 109 can be suppressed. As a result, the lifetime can be extended.

  In addition, according to the VCSEL 100 according to the first embodiment, each semiconductor layer has a relatively high thermal conductivity, and thus is generated in the element portion via a plurality of semiconductor layers left between the grooves. Heat can be easily released to the external area. Therefore, the temperature rise of the multiple quantum well active layer 104 is suppressed, and the light output characteristics and temperature characteristics are improved.

  Further, according to the VCSEL 100 according to the first embodiment, the p-type upper DBR 107 and the resonator structure are removed and planarized with the polyimide 111 under the wiring 113 and the bonding pad 114 (on the −Z side). . The dielectric constant of polyimide is as small as about one third of each semiconductor layer, and an insulating dielectric having a low dielectric constant is several μm between the wiring 113 and the bonding pad 114 and the n-side ohmic electrode 115. It will be thick. Therefore, the parasitic capacitance formed by the wiring 113 and the bonding pad 114 and the n-side ohmic electrode 115 can be significantly reduced. Therefore, the modulation frequency can be increased.

<< Second Embodiment >>
The second embodiment of the present invention will be described below with reference to FIGS. FIG. 3 shows a schematic configuration of a VCSEL 200 according to the second embodiment of the present invention. In FIG. 3, the left-right direction of the paper is the X-axis direction, the vertical direction of the paper is the Y-axis direction, and the direction perpendicular to the paper is the Z-axis direction. FIG. 4 shows an AA cross section of the VCSEL 200 of FIG.

  The VCSEL 200 is different from the VCSEL 100 according to the first embodiment in that proton ions are implanted into each semiconductor layer other than the current path surrounded by the Al oxide layer 109 to form a high resistance region 210. Has characteristics. In the following description, differences from the first embodiment will be mainly described, and the same reference numerals are used for the same or equivalent components as in the first embodiment, and the description thereof will be simplified or omitted. Shall.

  In the VCSEL 200, as shown in FIG. 4, an n-type lower DBR 202, a lower spacer layer 203, a multiple quantum well (MQW) active layer 204, an upper spacer layer 205, and an upper spacer layer 205 are formed on the n-type GaAs substrate 101 (+ Z side). Semiconductor layers such as p-type upper DBR 207 are sequentially stacked by epitaxial growth.

The n-type lower DBR 202 includes a high-refractive index layer made of n-type GaAs and a low-refractive index layer made of n-type Al _0.9 Ga _0.1 As, each having a quarter of the oscillation wavelength (980 nm). The layers are alternately stacked with a thickness that provides an optical length.

  The lower spacer layer 203 is a layer made of GaAs.

  The multiple quantum well active layer 204 is a layer made of GaInAs / GaAs.

  The upper spacer layer 205 is a layer made of GaAs.

In the p-type upper DBR 207, a high refractive index layer made of p-type GaAs and a low refractive index layer made of p-type Al _0.9 Ga _0.1 As each have an optical length of ¼ of the oscillation wavelength. Are alternately stacked with a thickness of The p-type upper DBR 207 has an AlAs layer 106 in the vicinity of the boundary with the upper spacer layer 205.

  A region sandwiched between the n-type lower DBR 202 and the p-type upper DBR 207 has a thickness that is an optical length corresponding to one wavelength of the oscillation wavelength, and constitutes a so-called resonator structure.

  By flowing a forward current between the p-side ohmic electrode 112 and the n-side ohmic electrode 115, carriers are injected into the multiple quantum well active layer 204 to emit light. At this time, the current is confined to the central non-oxidized region 117 by the Al oxide layer 109. The light emitted from the multiple quantum well active layer 204 resonates at the resonator structure and is emitted in the + Z direction as laser light having a wavelength of 980 nm.

  As described above, according to the VCSEL 200 according to the second embodiment, since the element portion and its external region are connected by epi (crystal growth layer), the Al oxide layer 109 is selectively oxidized. And the non-oxidized part are connected as a whole. Thereby, the mechanical strength of the laminate is increased, thereby reducing the influence of the stress generated in the Al oxide layer 109, and the generation of defects from the Al oxide layer 109 can be suppressed. As a result, the lifetime can be extended.

  In addition, according to the VCSEL 200 according to the second embodiment, each semiconductor layer has a relatively high thermal conductivity, and thus is generated in the element portion via a plurality of semiconductor layers left between the grooves. Heat can be easily released to the external area. Therefore, the temperature rise of the multiple quantum well active layer 204 is suppressed, and the light output characteristics and temperature characteristics are improved.

  Further, according to the VCSEL 200 according to the second embodiment, the p-type upper DBR 207 and the resonator structure are removed and planarized with the polyimide 111 under the wiring 113 and the bonding pad 114 (on the −Z side). . The dielectric constant of polyimide is as small as about one third of each semiconductor layer, and an insulating dielectric having a low dielectric constant is several μm between the wiring 113 and the bonding pad 114 and the n-side ohmic electrode 115. It will be thick. Therefore, the parasitic capacitance formed by the wiring 113 and the bonding pad 114 and the n-side ohmic electrode 115 can be significantly reduced.

  Further, according to the VCSEL 200 according to the second embodiment, since the high resistance region 210 exists between the p-type ohmic electrode 112 and the n-type ohmic electrode 115, the p-type ohmic electrode 112 and the n-type ohmic electrode 115 are present. , And the modulation frequency can be further increased.

  Further, according to the VCSEL 200 according to the second embodiment, the leakage of current to the outside of the current path can be further reduced by the high resistance region 210, and the threshold current is lower than that of the VCSEL 100 in the first embodiment. It becomes possible to operate with.

<< Third Embodiment >>
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 shows a schematic configuration of a VCSEL 300 according to the third embodiment of the present invention. In FIG. 5, the left-right direction of the paper surface is the X-axis direction, the vertical direction of the paper surface is the Y-axis direction, and the direction perpendicular to the paper surface is the Z-axis direction. FIG. 6 shows an AA cross section of the VCSEL 200 of FIG.

  This VCSEL 300 is characterized in that the components of the multiple quantum well active layer are different from the VCSEL 200 in the second embodiment described above. In the following description, the differences from the first and second embodiments will be mainly described, and the same or equivalent components as those in the first and second embodiments will be denoted by the same reference numerals, and the description thereof will be made. Shall be simplified or omitted.

  In the VCSEL 300, as shown in FIG. 6, an n-type lower DBR 202, a lower spacer layer 203, a multiple quantum well (MQW) active layer 304, an upper spacer layer 205, and an n-type GaAs substrate 101 (+ Z side) Semiconductor layers such as p-type upper DBR 207 are sequentially stacked by epitaxial growth.

In the n-type lower DBR 202, a high-refractive index layer made of n-type GaAs and a low-refractive index layer made of n-type Al _0.9 Ga _0.1 As each have a quarter of the oscillation wavelength (1300 nm). The layers are alternately stacked with a thickness that provides an optical length.

  The multiple quantum well active layer 304 is a layer made of GaInNAs / GaNAs.

In the p-type upper DBR 207, a high refractive index layer made of p-type GaAs and a low refractive index layer made of p-type Al _0.9 Ga _0.1 As have an optical length of one quarter of the oscillation wavelength. Are alternately stacked with a thickness of The p-type upper DBR 207 has an AlAs layer 106 in the vicinity of the boundary with the upper spacer layer 205.

  A region sandwiched between the n-type lower DBR 202 and the p-type upper DBR 207 has a thickness that is an optical length corresponding to one wavelength of the oscillation wavelength, and constitutes a so-called resonator structure.

  As shown in FIG. 5, three grooves (302a, 302b, 302c) are formed in the laminate. In particular, the groove 302 c is formed in a size larger than the wiring 113 and the bonding pad 114. Each groove has a depth at least across the AlAs layer 106. Here, as an example, the bottom surface of each groove reaches the n-type lower DBR 202. That is, each groove is formed by removing the p-type upper DBR 207 and the resonator structure.

  In the groove 302c, polyimide 111 is embedded to flatten the groove. A bonding pad 114 is formed on the polyimide 111. The bonding pad 114 is connected to the p-side ohmic electrode 112 through the wiring 113.

  By flowing a forward current between the p-side ohmic electrode 112 and the n-side ohmic electrode 115, carriers are injected into the multiple quantum well active layer 304 to emit light. At this time, the current is confined to the central non-oxidized region 117 by the Al oxide layer 109. The light emitted from the multiple quantum well active layer 304 resonates at the resonator structure and is emitted in the + Z direction as laser light having a wavelength of 1300 nm.

  That is, a region surrounded by three grooves in the stacked body is an element portion.

  As described above, according to the VCSEL 300 according to the third embodiment, since the element portion and its external region are connected by epi (crystal growth layer), the Al oxide layer 109 is selectively oxidized. And the non-oxidized part are connected as a whole. Thereby, the mechanical strength of the laminate is increased, thereby reducing the influence of the stress generated in the Al oxide layer 109, and the generation of defects from the Al oxide layer 109 can be suppressed. As a result, the lifetime can be extended.

  In addition, according to the VCSEL 300 according to the third embodiment, each semiconductor layer has a relatively high thermal conductivity, and thus is generated in the element portion via a plurality of semiconductor layers left between the grooves. Heat can be easily released to the external area. Therefore, the temperature rise of the multiple quantum well active layer 304 is suppressed, and the light output characteristics and temperature characteristics are improved.

  Further, according to the VCSEL 300 according to the third embodiment, the p-type upper DBR 207 and the resonator structure are removed and planarized with the polyimide 111 under the wiring 113 and the bonding pad 114 (on the −Z side). . The dielectric constant of polyimide is as small as about one third of each semiconductor layer, and an insulating dielectric having a low dielectric constant is several μm between the wiring 113 and the bonding pad 114 and the n-side ohmic electrode 115. It will be thick. Therefore, the parasitic capacitance formed by the wiring 113 and the bonding pad 114 and the n-side ohmic electrode 115 can be significantly reduced.

  Further, according to the VCSEL 300 according to the third embodiment, since the high resistance region 210 exists between the p-type ohmic electrode 112 and the n-type ohmic electrode 115, the p-type ohmic electrode 112 and the n-type ohmic electrode 115 are present. , And the modulation frequency can be further increased.

  Further, according to the VCSEL 300 according to the third embodiment, the leakage of current to the outside of the current path can be further reduced by the high resistance region 210, and the threshold current is lower than that of the VCSEL 100 in the first embodiment. It becomes possible to operate with.

  Further, according to the VCSEL 300 according to the third embodiment, GaInNAs which is a mixed crystal semiconductor of nitrogen and another group V element is used as the multiple quantum well active layer 304. GaInNAs can increase the confinement barrier height of conduction band electrons with a spacer layer (barrier layer) such as GaAs to about 300 meV, so that the overflow of electrons from the multiple quantum well active layer 304 can be suppressed. . GaInNAs can be epitaxially grown on the n-type lower DBR 202 having high reflectivity and high thermal conductivity, and a VCSEL with good performance having an oscillation wavelength of 1.3 μm band can be obtained.

  Note that mixed crystal semiconductors containing nitrogen and other group V elements include GaNAs, GaInNAs, AlGaNAs, AlGaInNAs, GaNAsP, GaInNAsP, AlGaNAsP, AlGaInNAsP, GaNAsSb, GaInNAsSb, AlGaNAsSb, AlGaInNASSPS, GaNAPSPS, InGaPSPS, InGaPS There is.

  In each of the above embodiments, the case where the p-type upper DBR has the AlAs layer 106 has been described. However, the present invention is not limited to this. In short, any one of the p-type upper DBR, the resonator structure, and the n-type lower DBR may have the AlAs layer 106.

  In each of the above embodiments, the case where the p-type upper DBR and the resonator structure located under the wiring 113 and the bonding pad 114 (on the −Z side) and the resonator structure are removed and planarized with the polyimide 111 has been described. However, the present invention is not limited to this, and the AlAs layer 106 positioned below (−Z side) the wiring 113 and the bonding pad 114 may be cut.

  FIG. 7 shows a schematic configuration of an optical transmission system 400 according to an embodiment of the present invention. In this optical transmission system 400, an optical transmission module 401 and an optical reception module 405 are connected by an optical fiber cable 404, and one-way optical communication from the optical transmission module 401 to the optical reception module 405 is possible.

  The optical transmission module 401 includes a light source 402 including any one of the VCSELs 100, 200, and 300, and a drive circuit that modulates the light intensity of the laser light emitted from the light source 402 in accordance with an electrical signal input from the outside. 403.

  The optical signal output from the light source 402 is coupled to the optical fiber cable 404, guided through the optical fiber cable 404, and input to the optical reception module 405.

  The optical receiving module 405 includes a light receiving element 406 that converts an optical signal into an electric signal, and a receiving circuit 407 that performs signal amplification, waveform shaping, and the like on the electric signal output from the light receiving element 406.

  According to the optical transmission module 401 according to the present embodiment, since the light source 402 includes any one of the VCSELs 100, 200, and 300, it can be operated at a high modulation frequency. Therefore, high-capacity optical transmission with low power consumption and high speed can be realized.

  In addition, the optical transmission system 400 according to the present embodiment includes the optical transmission module 401 that can be operated at a high modulation frequency, and thus can perform high-capacity optical transmission with low power consumption and high speed. It becomes possible.

  In the present embodiment, a configuration example of unidirectional communication of a single channel is shown, but a configuration of bidirectional communication, a parallel transmission method, a wavelength division multiplex transmission method, or the like can also be adopted. In short, the light source 402 only needs to include one of the VCSELs 100, 200, and 300.

  As described above, the vertical cavity surface emitting semiconductor laser according to the present invention is suitable for suppressing a decrease in high-frequency characteristics without causing a decrease in mechanical strength. Further, the optical transmission module of the present invention is suitable for enabling high-speed optical transmission. The optical transmission system of the present invention is suitable for performing optical transmission at high speed.

It is a figure for demonstrating schematic structure of VCSEL which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the AA cross section of VCSEL of FIG. It is a figure for demonstrating schematic structure of VCSEL which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the AA cross section of VCSEL of FIG. It is a figure for demonstrating schematic structure of VCSEL which concerns on the 3rd Embodiment of this invention. It is a figure for demonstrating the AA cross section of VCSEL of FIG. It is a figure for demonstrating schematic structure of the optical transmission module and optical transmission system which concern on one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... VCSEL, 101 ... n-type GaAs substrate, 102 ... Lower distributed Bragg reflector, 103 ... Lower spacer layer, 104 ... Multiple quantum well active layer, 105 ... Upper spacer layer, 106 ... AlAs layer, 107 ... Upper distributed Bragg reflection Mirror, 108a ... groove, 108b ... groove, 108c ... groove, 108d ... groove, 109 ... Al oxide layer, 111 ... polyimide, 112 ... p-side ohmic electrode, 113 ... wiring, 114 ... bonding pad, 115 ... n-side ohmic electrode , 200 ... VCSEL, 204 ... multiple quantum well active layer, 300 ... VCSEL, 302a ... groove, 302b ... groove, 302c ... groove, 304 ... multiple quantum well active layer, 400 ... optical transmission system, 401 ... optical transmission module.

Claims (7)

A lower multilayer reflector, a resonator structure including an active layer, and an upper multilayer reflector are stacked on a substrate, and aluminum is provided in any of the lower multilayer reflector, the resonator structure, and the upper multilayer reflector. In a vertical cavity surface emitting semiconductor laser in which an upper electrode and a bonding pad are formed on an upper surface of a stacked body including an oxidizable layer including: the upper electrode is connected to the bonding pad by a wiring;
In the laminate, at least the layer to be oxidized located under the wiring and the bonding pad is removed by etching to form a recess, and an insulating dielectric is embedded in the recess. A surface emitting semiconductor laser.   The surface emitting semiconductor laser according to claim 1, wherein the insulating dielectric is polyimide.   3. A proton ion is implanted into at least a part of the stacked body excluding a current path surrounded by an insulating region formed by selectively oxidizing the layer to be oxidized. The light emitting semiconductor laser described in 1.   The surface-emitting semiconductor laser according to claim 1, wherein the active layer is made of a mixed crystal semiconductor containing nitrogen and another group V element. In addition to the recess in which the insulating dielectric is embedded, at least one recess from which at least the oxidized layer is removed by etching is further formed in the laminate.
The surface emitting semiconductor laser according to claim 1, wherein the oxidized layer is selectively oxidized through the plurality of recesses. An optical transmission module that generates an optical signal according to an input electrical signal,
A surface emitting semiconductor laser according to claim 1;
An optical transmission module comprising: a driving device that drives the surface-emitting semiconductor laser according to the input electrical signal. The optical transmission module according to claim 6, which generates an optical signal corresponding to an input electrical signal;
An optical transmission means for transmitting the optical signal;
An optical transmission system comprising: a conversion device that converts an optical signal via the optical transmission means into an electrical signal.

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