JP2012089800A - Semiconductor laser and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser which can be easily made into a thin package by wireless connection.SOLUTION: The semiconductor laser comprises a first conductive type cladding layer 14, an active layer 16, a second conductive type cladding layer 18 and a surface electrode layer 20 sequentially arranged on a substrate 10; a rear face electrode layer 22 arranged on a rear face of the substrate 10; a first insulator layer 24a formed along a first cleavage surface 42a of the substrate 10, the first conductive type cladding layer 14, the active layer 16 and the second conductive type cladding layer 18, and extending on the surfaces of the first cleavage surface 42a and the surface electrode layer 20 and on the surface of the rear face electrode layer 22; a second insulator layer 24b formed along a second cleavage surface 42b opposed to the first cleavage surface 42a and extending on the surfaces of the second cleavage surface 42b and the surface electrode layer 20 and on the surface of the rear face electrode layer 22; and a first electrode layer 26A arranged on one part on the first insulator layer 24a and on the surface electrode layer 20.

Description

  The present invention relates to a semiconductor laser and a manufacturing method thereof, and more particularly, to a semiconductor laser and a manufacturing method thereof that can be easily formed into a thin package by wireless connection.

  Conventional light emitting diodes (LEDs) and semiconductor lasers (LDs: Laser Diodes) are epitaxially grown on a substrate due to their structures, and electrodes are formed on the epitaxial growth layer.

  At the time of assembling the element, it is necessary to perform wire bonding with respect to the electrode disposed on the epitaxial growth layer, which is an obstacle to realizing a thin package (for example, Patent Document 1 and Patent Document 2). reference.).

  A schematic bird's-eye view structure for explaining the mounting state of the LD according to the conventional example is expressed as shown in FIG. As shown in FIG. 21, the mounting structure of the LD according to the conventional example is configured such that the laser chip 401 is installed on the submount 402 with the junction up (the back side of the GaN-based semiconductor substrate is the heat sink 407 side). The p-side electrode is wire-bonded to obtain a finished product. The energization pin 403 and the p-side electrode are connected by a gold (Au) wire 405, and the energization pin 404 and the n-side electrode are connected by an Au wire 406.

  Due to the structure of the conventional LD, it is necessary to perform wire bonding when assembling the element, and it is difficult to make a thin package. Further, in the case of a surface emitting LD, the light extraction efficiency from the upper part of the element is poor.

Japanese Utility Model Publication No. 5-4529 JP 2000-77726 A

  An object of the present invention is to provide a semiconductor laser that can be easily made into a thin package by wireless connection and a method for manufacturing the same.

  According to one aspect of the present invention, a substrate, a first conductivity type cladding layer disposed on the substrate, an active layer disposed on the first conductivity type cladding layer, and disposed on the active layer. A second conductivity type cladding layer, a surface electrode layer disposed on the second conductivity type cladding layer, a back electrode layer disposed on the back surface of the substrate, the substrate, the first conductivity type cladding layer, The active layer is formed along a first cleaved surface of the second conductivity type cladding layer, and is arranged to extend on the surface of the first cleaved surface and the surface electrode layer and on the surface of the back electrode layer. And a first insulating layer and a second cleaved surface opposite to the first cleaved surface, and extends on the second cleaved surface, the surface of the surface electrode layer, and the surface of the back electrode layer. A second insulating layer arranged on the first insulating layer and the surface electrode layer A semiconductor laser and a first electrode layer disposed on a part is provided.

  According to another aspect of the present invention, a substrate, a first conductivity type cladding layer disposed on the substrate, an active layer disposed on the first conductivity type cladding layer, and disposed on the active layer. Second conductive type cladding layer, surface electrode layer disposed on the second conductive type cladding layer, back electrode layer disposed on the back surface of the substrate, the substrate, and the first conductive type cladding layer The active layer is formed along the first side surface of the second conductivity type cladding layer, and extends on the surface of the first side surface and the surface electrode layer and on the surface of the back electrode layer. There is provided a semiconductor laser comprising a first insulating layer and a first electrode layer disposed on a part of the first insulating layer and on the surface electrode layer.

  According to another aspect of the present invention, a step of forming a first conductivity type cladding layer on a substrate, a step of forming an active layer on the first conductivity type cladding layer, and a second conductivity on the active layer. Forming a mold cladding layer, forming a surface electrode layer on the second conductivity type cladding layer, forming a back electrode layer on the back surface of the substrate, the substrate, the first conductivity type Extending along the first cleaved surface of the clad layer, the active layer, and the second conductivity type clad layer on the surface of the first cleaved surface and the surface electrode layer and on the surface of the back electrode layer A step of forming one insulating layer, and a second cleaved surface facing the first cleaved surface, and extending on the surface of the second cleaved surface and the surface electrode layer and on the surface of the back electrode layer. Forming a second insulating layer, and on the first insulating layer and the surface electrode The method of manufacturing a semiconductor laser and a step of forming a first electrode layer is provided on a part of the upper.

  According to another aspect of the present invention, a step of forming a first conductivity type cladding layer on a substrate, a step of forming an active layer on the first conductivity type cladding layer, and a second conductivity on the active layer. Forming a mold cladding layer, forming a surface electrode layer on the second conductivity type cladding layer, forming a back electrode layer on the back surface of the substrate, the substrate, the first conductivity type The first insulation extends along the first side surface of the cladding layer, the active layer, and the second conductivity type cladding layer on the surface of the first side surface and the front electrode layer and on the surface of the back electrode layer. There is provided a method for manufacturing a semiconductor laser, comprising a step of forming a layer and a step of forming a first electrode layer on a part of the first insulating layer and the surface electrode layer.

  According to the present invention, it is possible to provide a semiconductor laser that can be easily packaged thinly and a manufacturing method thereof by wireless connection.

1 is a schematic bird's-eye view of a semiconductor laser according to a first embodiment of the present invention. The typical bird's-eye view which shows a mode that the semiconductor laser which concerns on the 1st Embodiment of this invention is mounted on a semiconductor mounting board | substrate. 1 is a schematic cross-sectional structure diagram in which a semiconductor laser according to a first embodiment of the present invention is mounted on a semiconductor mounting substrate. The typical plane pattern block diagram of the electrode pattern on the semiconductor mounting board | substrate of the semiconductor laser which concerns on the 1st Embodiment of this invention. 1 is a schematic bird's-eye view showing a state in which a semiconductor laser according to a first embodiment of the present invention is mounted on an insulating mounting substrate. 1 is a schematic cross-sectional structure diagram in which a semiconductor laser according to a first embodiment of the present invention is mounted on an insulating mounting substrate. The typical plane pattern block diagram of the electrode pattern on the insulated mounting board | substrate of the semiconductor laser which concerns on the 1st Embodiment of this invention. In the manufacturing method of the semiconductor laser according to the first embodiment of the present invention, (a) a schematic cross-sectional structure diagram showing one step of a wafer process (part 1), (b) a schematic showing one step of a wafer process Sectional structure diagram (No. 2), (c) Schematic sectional structure diagram showing one step of wafer process (No. 3), (d) Schematic sectional structure diagram showing one step of wafer process (No. 4). In the semiconductor laser manufacturing method according to the first embodiment of the present invention, (a) a schematic bird's-eye view showing a state of dividing an LD wafer, and (b) a plurality of LD bars formed by dividing the LD wafer. Schematic bird's-eye view. FIG. 3 is a schematic bird's-eye view showing one step of stacking an LD bar and a silicon bar and inserting the LD bar and the silicon bar into the LD bar fixing device in the semiconductor laser manufacturing method according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional structure diagram showing one step of laminating an LD bar and a silicon bar in the semiconductor laser manufacturing method according to the first embodiment of the present invention. The typical bird's-eye view of the silicon bar used for the manufacturing method of the semiconductor laser concerning a 1st embodiment of the present invention. FIG. 5 is a schematic diagram showing a step of forming an insulating layer on a side wall of a laminated LD bar, a part of a front electrode layer, and a part of a back electrode layer in the method for manufacturing a semiconductor laser according to the first embodiment of the present invention. FIG. FIG. 14 is a schematic cross-sectional structure diagram showing a step of stacking an LD bar and an inverted silicon bar after the step of FIG. 13 in the semiconductor laser manufacturing method according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional structure diagram showing a step of forming an electrode layer on the insulating layer of the laminated LD bar and a part of the surface electrode layer in the method for manufacturing a semiconductor laser according to the first embodiment of the present invention. 1 is a schematic bird's-eye view of a GaAs stripe LD applied to a semiconductor laser according to a first embodiment of the present invention. 1 is a schematic bird's-eye view of a GaN-based stripe LD applied to a semiconductor laser according to a first embodiment of the present invention. FIG. 3 is a schematic bird's-eye view of another GaN-based stripe LD applied to the semiconductor laser according to the first embodiment of the present invention. FIG. 5 is a schematic bird's-eye view of a semiconductor laser according to a second embodiment of the present invention. The typical bird's-eye view of GaAs type surface emitting LD applied to the semiconductor laser concerning a 2nd embodiment of the present invention. The typical bird's-eye view explaining the mounting mounting state of LD concerning a conventional example.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The first to second embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the embodiments of the present invention include components. The material, shape, structure, arrangement, etc. are not specified below. Various modifications can be made to the embodiment of the present invention within the scope of the claims.

[First embodiment]
A schematic bird's-eye view configuration of the semiconductor laser 1 according to the first embodiment of the present invention is expressed as shown in FIG. Further, a schematic bird's-eye view showing a state in which the semiconductor laser 1 according to the first embodiment is mounted on the semiconductor mounting substrate 32S is expressed as shown in FIG. Further, a schematic cross-sectional structure actually mounted on the semiconductor mounting substrate 32S is expressed as shown in FIG. Further, a schematic planar pattern configuration of the electrode pattern on the semiconductor mounting substrate 32S is expressed as shown in FIG. A schematic cross-sectional structure taken along line II, in which the semiconductor laser 1 according to the first embodiment is mounted on the electrode pattern of FIG. 4, corresponds to FIG.

  As shown in FIG. 1, the semiconductor laser 1 according to the first embodiment is disposed on a substrate 10, a first conductivity type cladding layer 14 disposed on the substrate 10, and the first conductivity type cladding layer 14. Active layer 16, second conductivity type cladding layer 18 disposed on active layer 16, surface electrode layer 20 disposed on second conductivity type cladding layer 18, and disposed on the back surface of substrate 10. The back electrode layer 22 is formed along the first cleaved surface 42 a of the substrate 10, the first conductivity type clad layer 14, the active layer 16, and the second conductivity type clad layer 18, and the first cleaved surface 42 a and the surface electrode layer 20 are formed. The first insulating layer 24a is disposed so as to extend on the front surface and the surface of the back electrode layer 22, and the second cleaved surface 42b is formed along the second cleaved surface 42b opposite to the first cleaved surface 42a. And on the surface of the front electrode layer 20 and the back electrode layer 2 Comprising the second insulating layer 24b which is arranged extending over the surface, and a first electrode layer 26A disposed on a part of the on the first insulating layer 24a and the surface electrode layer 20.

  As shown in FIG. 1, in the semiconductor laser 1 according to the first embodiment, the surface electrode layer 20 includes a laser stripe 80, and extends from the active layer 16 along the laser stripe 80 via the second insulating layer 24b. The laser beam hνf is emitted.

  As shown in FIG. 2 and FIG. 3, in the semiconductor laser 1 according to the first embodiment, the first electrode layer 26A connected to the front electrode layer 20 is an anode of the LD, and the back electrode layer 22 is an LD. The cathode.

  As shown in FIGS. 2 and 3, the semiconductor laser 1 according to the first embodiment includes a semiconductor mounting substrate 32S, an anode electrode pattern 30A disposed on the semiconductor mounting substrate 32S, and a semiconductor mounting substrate 32S. And a cathode electrode pattern 30K disposed via an insulating layer 30I.

  As shown in FIGS. 2 and 3, on the semiconductor mounting substrate 32S, the first electrode layer 26A is placed on and connected to the anode electrode pattern 30A, and the back electrode layer 22 is placed on the cathode electrode pattern 30K. Placed and connected. Here, the cathode electrode 28 may be integrally formed on the cathode electrode pattern 30K. Further, the cathode electrode 28 may be connected to the back electrode layer 22 in advance. In this case, the cathode electrode 28 is placed on and connected to the cathode electrode pattern 30K.

  In FIG. 2, in order to adjust the optical distance, alignment marks (not shown) are arranged on the semiconductor mounting substrate 32S and image processing is performed to adjust the position of the laser end face of the semiconductor laser 1, or The end face of the semiconductor laser 1 and the end face of the semiconductor mounting substrate 32S may be aligned.

  In the semiconductor laser 1 according to the first embodiment, for example, a silicon substrate is applied to the semiconductor mounting substrate 32S.

  A schematic bird's-eye view showing a state in which the semiconductor laser 1 according to the first embodiment is mounted on the insulating mounting substrate 32I is expressed as shown in FIG. Further, a schematic cross-sectional structure actually mounted on the insulating mounting board 32I is expressed as shown in FIG. Further, a schematic plane pattern configuration of the electrode pattern on the insulating mounting substrate 32I is expressed as shown in FIG. A schematic cross-sectional structure taken along the line II-II in which the semiconductor laser 1 according to the first embodiment is mounted on the electrode pattern of FIG. 7 corresponds to FIG.

  As shown in FIGS. 5 and 6, the semiconductor laser 1 according to the first embodiment includes an insulating mounting board 32I, an anode electrode pattern 30A disposed on the insulating mounting board 32I, and an insulating mounting board 32I. The cathode electrode pattern 30K may be provided.

  As shown in FIGS. 5 and 6, on the insulating mounting substrate 32I, the first electrode layer 26A is placed on and connected to the anode electrode pattern 30A, and the back electrode layer 22 is placed on the cathode electrode pattern 30K. Placed and connected. Here, the cathode electrode 28 may be integrally formed on the cathode electrode pattern 30K. Further, the cathode electrode 28 may be connected to the back electrode layer 22 in advance. In this case, the cathode electrode 28 is placed on and connected to the cathode electrode pattern 30K.

In the semiconductor laser 1 according to the first embodiment, for example, an aluminum nitride (AlN) substrate or an alumina (Al ₂ O ₃ ) substrate can be applied to the insulating mounting substrate 32I.

  The first electrode layer 26A may include a thin metal layer such as Au or a transparent electrode layer. As the transparent electrode layer, for example, ITO, ITZO, ZnO or the like can be applied.

  Further, in the semiconductor laser 1 according to the first embodiment, as shown in FIGS. 1, 3, and 6, the light is emitted from the active layer 16 through the first insulating layer 24a and the first electrode layer 26A. A monitor light detecting photodiode 90 for detecting the monitor light hνr may be provided. Note that it is desirable that the monitor light detecting photodiode 90 has sensitivity to the wavelength of the laser beam hνf emitted from the semiconductor laser 1.

  In the semiconductor laser 1 according to the first embodiment, the anode electrode pattern 30A and the first electrode layer 26A, and the cathode electrode pattern 30K and the back electrode layer 22 are soldered. That is, the first electrode layer 26A is connected to the anode electrode pattern 30A by die bonding, and the back electrode layer 22 is connected to the cathode electrode pattern 30K via the cathode electrode 28 by die bonding.

  Here, for example, the substrate 10 is formed of GaAs, the first conductivity type cladding layer 14 and the second conductivity type cladding layer 18 are formed of an AlInGaP layer, and the active layer 16 is formed of an InGaP / AlInGaP pair. A multi-quantum well (MQW) layer is formed.

Here, the (Al _x Ga _1-x ) _y In _1-y P (0 <= x <1, 0 <y <= 1) layer is simplified and expressed as an AlInGaP layer, and corresponds to x = 0. The Ga _y In _1-y P (0 <y <= 1) layer is simplified and displayed as an InGaP layer.

  One or both of the first insulating layer 24a and the second insulating layer 24b are formed of a silicon insulating film, a silicon nitride film, or the like.

One or both of the first insulating layer 24a and the second insulating layer 24b may include a distributed black reflection (DBR) layer. The DBR layer includes any one of ZrO ₂ , Al ₂ O ₃ , SiO ₂ , TiO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , AlN, SiN, AlON, SiON, and AlN _x (0 <x <1). It may be formed of a multilayer film. Here, AlN _x (0 <x <1) indicates a case where the composition ratio deviates from the stoichiometry control of AlN.

Further, the DBR layer has a high light reflection characteristic, and may have a laminated structure including, for example, a ZrO ₂ film and a SiO ₂ film. The thickness d1 of the ZrO ₂ film and the thickness d2 of the SiO ₂ film are formed such that d1 = λ / 4n ₁ and d2 = λ / 4n ₂ . Here, n ₁ is the refractive index 2.18 of the ZrO ₂ film, and n ₂ is the refractive index 1.46 of the SiO ₂ film.

One or both of the first insulating layer 24a and the second insulating layer 24b may include an oxygen absorption layer. As the oxygen absorbing layer, any one of ZrO ₂ , Al ₂ O ₃ , SiO ₂ , TiO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , AlN, SiN, AlON, SiON, AlN _x (0 <x <1) is used. A containing layer is applicable.

(Production method)
The semiconductor laser manufacturing method according to the first embodiment includes a step of forming a first conductivity type cladding layer 14 on a substrate 10, a step of forming an active layer 16 on the first conductivity type cladding layer 14, A step of forming the second conductivity type cladding layer 18 on the active layer 16, a step of forming the surface electrode layer 20 on the second conductivity type cladding layer 18, and a back electrode layer 22 on the back surface of the substrate 10. Process, along the first cleavage surface 42a of the substrate 10, the first conductivity type cladding layer 14, the active layer 16, and the second conductivity type cladding layer 18, on the front surface and the back surface of the first cleavage surface 42a and the surface electrode layer 20 The step of forming the first insulating layer 24a extending on the surface of the electrode layer 22, and the second cleaved surface 42b and the surface electrode layer 20 along the second cleaved surface 42b facing the first cleaved surface 42a. On the surface and on the surface of the back electrode layer 22 Mashimashi and a step of forming a second insulating layer 24b, and forming a first electrode layer 26A on a part of the on the first insulating layer 24a and the surface electrode layer 20.

  The semiconductor laser manufacturing method according to the first embodiment includes a step of forming the anode electrode pattern 30A on the semiconductor mounting substrate 32S, a step of forming the insulating layer 30I on the semiconductor mounting substrate 32S, and an insulating layer. The step of forming the cathode electrode pattern 30K on 30I, the step of forming the cathode electrode 28 on the cathode electrode pattern 30K, and the first electrode layer 26A are placed on the anode electrode pattern 30A on the semiconductor mounting substrate 32S. And a step of placing the back electrode layer 22 on the cathode electrode pattern 30K.

  The semiconductor laser manufacturing method according to the first embodiment includes a step of forming the anode electrode pattern 30A on the insulating mounting substrate 32I, a step of forming the cathode electrode pattern 30K on the insulating mounting substrate 32I, and a cathode The step of forming the cathode electrode 28 on the electrode pattern 30K, and the first electrode layer 26A is placed on the anode electrode pattern 30A and the back electrode layer 22 is placed on the cathode electrode pattern 30K on the insulating mounting substrate 32I. And a step of placing.

  In the semiconductor laser manufacturing method according to the first embodiment, a schematic cross-sectional structure showing one step of the wafer process is expressed as shown in FIGS. 8 (a) to 8 (d). In addition, a schematic bird's-eye view structure showing how the LD wafer 34 is cleaved along the cleavage plane, and a schematic bird's-eye view structure of a plurality of LD bars 36 formed by cleaving the LD wafer 34 along the cleavage plane, respectively, It is expressed as shown in FIGS. 9 (a) and 9 (b).

  Also, a schematic bird's-eye view structure showing one step of inserting the laminated structure 50 in which a plurality of LD bars 36 and silicon bars 40 are laminated into the LD bar fixing device 38 is expressed as shown in FIG.

  Further, a schematic cross-sectional structure showing one step of forming a laminated structure 50 in which a plurality of LD bars 36 and silicon bars 40 are laminated is expressed as shown in FIG.

  A schematic bird's-eye view structure of the silicon bar 40 used in the method for manufacturing the semiconductor light emitting device according to the first embodiment is expressed as shown in FIG.

  A schematic cross-sectional structure showing a process of forming the first insulating layer 24a and the second insulating layer 24b on the side wall of the laminated LD bar 36, a part of the front electrode layer 20 and a part of the back electrode layer 22 is shown in FIG. As shown in FIG.

  A schematic cross-sectional structure showing one step of stacking the LD bar 36 and the inverted silicon bar 40 after the step of FIG. 13 is expressed as shown in FIG.

  A schematic cross-sectional structure showing a step of forming the first electrode layer 26A on the first insulating layer 24a, the second insulating layer 24b, and a part of the surface electrode layer 20 of the laminated LD bar 36 is shown in FIG. It is expressed as follows.

  A method for manufacturing the semiconductor laser according to the first embodiment will be described below.

(A) First, as shown in FIG. 8A, a first conductive layer is formed on a GaAs substrate 10 by using molecular beam epitaxy (MBE), MOCVD (Metal Organic Chemical Vapor Deposition), or the like. The mold clad layer 14, the active layer (MQW) 16, and the second conductivity type clad layer 18 are sequentially formed.

(B) Next, as shown in FIG. 8B, the surface electrode layer 20 is formed on the second conductivity type cladding layer 18 by using a sputtering method, a vacuum deposition method or the like.

(C) Next, as shown in FIG. 8C, the GaAs substrate 10 is thinned from the back surface. This thinning step can be performed by, for example, lapping, polishing, chemical mechanical polishing (CMP) technology, etching technology, or the like. As a result, for example, the thickness of the substrate 10 can be formed to about 90 μm. The thickness is not limited to this, and is about 30 μm to 250 μm.

(D) Next, as shown in FIG. 8D, the back electrode layer 22 is formed on the substrate 10 using a sputtering method, a vacuum evaporation method, or the like. As the material of the back electrode layer 22, for example, an Au layer or a laminated structure made of Au / AuGe-Ni alloy / Au can be used.

(E) Next, as shown in FIG. 9A, the LD wafer 34 is cleaved along the cleavage plane. As a result, as shown in FIG. 9B, a plurality of LD bars 36 having a width W and a length L can be formed.

(F) Next, as shown in FIG. 10, a laminated structure 50 in which a plurality of LD bars 36 and silicon bars 40 are laminated is inserted into the LD bar fixing device 38. Here, the detailed structure of the laminated structure 50 is expressed as shown in FIG. Since the structure of the silicon bar 40 has a convex shape as shown in FIG. 12, in the laminated structure 50, a part of the front electrode layer 20 and a part of the back electrode layer 22 are covered with the silicon bar 40. .

(G) Next, with the stacked structure 50 inserted in the LD bar fixing device 38, as shown in FIG. 13, the first insulating layer 24a and the second insulating layer 24b are formed by sputtering. That is, the first insulating layer 24a and the second insulating layer 24b are formed on the surface of the surface electrode layer 20 by the width of W3, respectively. Further, a first insulating layer 24a and a second insulating layer 24b are formed on the surface of the back electrode layer 22 by the width of W2 + W3, respectively. Here, the width W of the LD bar 36 has a relationship of W− (W1 + 2W2) = 2W3. In FIG. 13, an insulating layer is also formed on the side wall surface of the silicon bar 40, but the illustration is omitted for the sake of simplicity. Here, the first insulating layer 24a and the second insulating layer 24b are multilayer reflective films, the reflectance of the first insulating layer 24a is about 99%, and the reflectance of the second insulating layer 24b is about 60%. It also serves as a multilayer film for normal reflectance adjustment. The values of the reflectance are not limited to these values. For example, the reflectance of the first insulating layer 24a may be selected to be about 30 to 100%, and the reflectance of the second insulating layer 24b may be selected to be about 5 to 60%. it can.

(H) Next, as shown in FIG. 14, a plurality of LD bars 36 and inverted silicon bars 40 are stacked to form a stacked structure 50a. Note that the silicon bar 40 used in FIG. 14 is not necessarily applied to the silicon bar 40 used in FIG. 14, and a silicon bar having a different size is appropriately selected according to the width of the electrode layer. Is possible. Further, instead of the silicon bar 40, the LD bar 36 may be reversed.

(I) Next, in a state where the laminated structure 50a is inserted into the LD bar fixing device 38, as shown in FIG. 15, the first electrode layer 26A is formed using a sputtering method, a vacuum evaporation method, or the like. That is, the first electrode layer 26A is formed on the surface of the surface electrode layer 20 by the width of W2 + W3. The first electrode layer 26A is connected to the surface electrode layer 20 with a width of W2. Further, the first electrode layer 26A is formed on the surface of the back electrode layer 22 by the width of W3. Here, the thicknesses D1 and D2 of the silicon bar 40 shown in FIG. 12 have a thickness that can sufficiently secure the wraparound of the first electrode layer 26A formed using a sputtering method, a vacuum deposition method, or the like. Just do it. In FIG. 15, an electrode layer is also formed on the side wall surface of the silicon bar 40, but the illustration is omitted for the sake of simplicity.

(J) Next, the laminated structure 50a is removed from the LD bar fixing device 38, and the silicon bar 40 is removed. The LD bar 36 is divided, and as a result, the semiconductor laser 1 according to the first embodiment shown in FIG. 1 is obtained.

(K) Next, as shown in FIG. 2, the anode electrode pattern 30A and the cathode electrode pattern 30K are formed on the semiconductor mounting substrate 32S by using a vacuum deposition method, a sputtering method, etc., and patterned into a predetermined stripe shape or the like. .

(L) Next, as shown in FIG. 3, the semiconductor laser 1 is mounted on the semiconductor mounting substrate 32S, and the anode electrode pattern 30A and the cathode electrode pattern 30K are respectively placed on the first electrode layer 26A and the cathode electrode pattern 30K is placed on the back surface. The electrode layer 22 is connected by die bonding.

  According to the first embodiment, wire bonding is not required when assembling the semiconductor laser, and the package can be made thin.

  According to the first embodiment, since the semiconductor laser manufacturing method is simplified, the time required for the manufacturing process until chip formation can be shortened.

(GaAs stripe LD)
A schematic bird's-eye view configuration example of a GaAs stripe LD applicable to the semiconductor laser 1 according to the first embodiment is expressed as shown in FIG. In FIG. 16, the X direction is the extending direction of the laser stripe, that is, the direction perpendicular to the cleavage plane, and the Y direction is the direction orthogonal to the extending direction of the laser stripe, that is, the direction parallel to the cleavage plane.

  As shown in FIG. 16, the GaAs stripe LD applied to the semiconductor laser 1 according to the first embodiment includes a GaAs substrate 102, an n-type cladding layer 130 disposed on the GaAs substrate 102, and an n-type. An etching stop layer 131 disposed on the cladding layer 130, an n-type cladding layer 132 disposed on the etching stop layer 131, an active layer 133 disposed on the n-type cladding layer 132, and the active layer 133 The p-type cladding layer 134 disposed, the cap layer 104 disposed on the p-type cladding layer 134, the current blocking layers 105 and 106 disposed on the side walls of the p-type cladding layer 134 and the cap layer 104, and the cap A contact layer 101 disposed on the layer 104 and the current blocking layers 105, 106; and a contact layer 101 disposed on the contact layer 101. It comprises a deposited layer 135, and a plated electrode layer 136 disposed on the deposition layer 135.

  As shown in FIG. 16, both end portions of the plated electrode layer 136 are thinner than the center portion.

The n-type cladding layers 130 and 132 are made of, for example, Al _x1 Ga _1-x1 As (0.3 ≦ x1 ≦ 0.7, for example, x1 = 0.5). The n-type cladding layers 130 and 132 are doped with, for example, about 2 × 10 ¹⁸ cm ^{−3 of} Si.

The etching stop layer 131 is made of n-type or non-doped, for example, In _0.49 Ga _0.51 P, and is formed to have a thickness of about 0.01 μm to 0.05 μm, for example.

  The total thickness of the n-type cladding layer 130, the etching stop layer 131, and the n-type cladding layer 132 is, for example, about 2 μm to 4 μm.

The active layer 133 has a bulk structure of Al _y1 Ga _1-y1 As (0.05 ≦ y1 ≦ 0.2, for example, y1 = 0.15) or Al _y2 Ga _1-y2 As (0.01 ≦ y2 ≦ 0). .1, for example, y2 = 0.05) and a barrier layer made of Al _y3 Ga _1-y3 As (0.2 ≦ y3 ≦ 0.5, y2 <y3, for example, y3 = 0.3) Single Quantum Well (SQW)
Alternatively, the overall thickness is, for example, about 0.01 μm to 0.2 μm by the MQW structure.

The p-type cladding layer 134 is made of, for example, Al _x2 Ga _1-x2 As (0.3 ≦ x2 ≦ 0.7, for example, x2 = 0.5), and is formed to have a thickness of about 0.5 μm to 4 μm, for example. The In the p-type cladding layer 134, a p-type or non-doped etch stop layer (not shown) made of, for example, In _0.49 Ga _0.51 P is formed to a thickness of about 0.01 μm to 0.05 μm, for example.

  A structure in which a light guide layer is provided between the active layer 133 and the n-type cladding layer 132, and between the active layer 133 and the p-type cladding layer 134, and a beam expansion between the active layer 133 and the n-type cladding layer 132. Other semiconductor layers such as a structure in which layers are provided may be interposed between any of the layers.

In the above-described example, the example is an AlGaAs-based compound semiconductor. However, in the case of an InGaAlP-based compound, for example, In _0.49 (Ga _{1 -u} Al _u ) _0.51 P (0.45 ≦ u ≦ 0.8). For example, the n-type clad layer 132 and the p-type clad layer 134 can be formed by the u = 0.7) layer, and In _0.49 (Ga _{1 -v 1} Al _{v 1} ) _0.51 P (0 ≦ v 1 ≦ 0.25) For example, the active layer may have an SQW structure or an MQW structure based on v1 = 0) / In _0.49 (Ga _{1 -v2} Al _v2 ) _0.51 P (0.3 ≦ v2 ≦ 0.7, for example, v2 = 0.4). 133 can be formed.

The etching stop layer 131 is not limited to In _0.49 Ga _0.51 P, and for example, In _0.49 (Ga _0.8 Al _0.2 ) _0.51 P can be used.

Etching for forming a ridge portion in the p-type cladding layer 134 is as follows. For example, a mask made of SiO ₂ or SiN _x or the like is formed by CVD or the like, and the cap layer 104 is selectively etched by dry etching or the like, and then the p-type cladding layer is etched by an etchant such as HCl. By etching 134, a ridge portion is formed in a stripe shape as shown in FIG.

The cap layer 104 is made of, for example, p-type In _0.49 Ga _0.51 P and has a thickness of, for example, about 0.01 μm to 0.05 μm. The cap layer 104 is used to prevent the oxide layer or the like from being formed on the surface of the semiconductor stacked portion when the contact layer 101 is formed in a later step, thereby preventing contamination. It may be formed of other semiconductor layers such as GaAs. Further, as long as the surface can be prevented from being contaminated, it may be omitted.

  The contact layer 101 is formed on the cap layer 104 and the current blocking layers 105 and 106 by a p-type GaAs layer, for example, to a thickness of about 0.05 μm to 10 μm.

  As the current blocking layers 105 and 106, AlGaAs, GaAs, INAlP, or the like can be used.

  In the GaAs stripe LD applied to the semiconductor laser 1 according to the first embodiment, the number of LD elements arranged on the LD bar 36 is increased to generate a multi-beam laser beam of quad beam or higher. You can also. Here, when mounting on the semiconductor mounting substrate 32S, the same configuration as in FIG. 3 is possible, and when mounting on the insulating mounting substrate 32I, the same configuration as in FIG. 6 is possible.

  In the GaAs stripe LD applied to the semiconductor light emitting device according to the first embodiment, the n-type cladding layer 132, the active layer 133, and the p-type cladding layer 134 are, for example, for infrared light emission at 780 nm wavelength. AlGaAs-based compound semiconductors and, for example, InGaAlP-based compound semiconductors that emit red light at a wavelength of 650 nm are applicable.

  Moreover, the structure of FIGS. 2 to 3 or FIGS. 5 to 6 can be applied to the mounting structure of the GaAs stripe LD described above.

(GaN-based stripe LD)
A schematic bird's-eye view configuration example of a GaN-based stripe LD applicable to the semiconductor laser according to the first embodiment is expressed as shown in FIG.

  As shown in FIG. 17, a GaN-based stripe-type LD 170 applied to the semiconductor laser according to the first embodiment includes a GaN single crystal substrate 171 and a group III nitride formed on the GaN single crystal substrate 171 by crystal growth. An n-side electrode 173 formed so as to be in contact with the back surface of the GaN single crystal substrate 171 (a surface opposite to the group III nitride semiconductor laminate structure 172), and a group III nitride semiconductor laminate structure. It is a Fabry-Perot LD including a p-side electrode 140 formed so as to be in contact with the surface of 172.

  The GaN single crystal substrate 171 has an m-plane as a main surface, and a group III nitride semiconductor multilayer structure 172 is formed by crystal growth on the m-plane. Therefore, group III nitride semiconductor multilayer structure 172 is made of a group III nitride semiconductor having an m-plane as a crystal growth main surface.

  The group III nitride semiconductor multilayer structure 172 includes a light emitting layer 180, an n-type semiconductor layer 181, and a p-type semiconductor layer 182.

  The n-type semiconductor layer 181 is disposed on the GaN single crystal substrate 171 side with respect to the light-emitting layer 180, and the p-type semiconductor layer 182 is disposed on the p-side electrode 140 side with respect to the light-emitting layer 180.

  The light emitting layer 180 is sandwiched between the n-type semiconductor layer 181 and the p-type semiconductor layer 182 to form a double heterojunction.

  The n-type semiconductor layer 181 includes an n-type GaN contact layer 183 (for example, 2 μm thickness), an n-type AlGaN cladding layer 184 (1.5 μm thickness or less, for example, 1.0 μm thickness) and an n-type in order from the GaN single crystal substrate 171 side. A GaN guide layer 185 (for example, 0.1 μm thick) is laminated.

  On the other hand, the p-type semiconductor layer 182 has a p-type AlGaN electron blocking layer 186 (for example, 20 nm thickness), a p-type GaN guide layer 187 (for example, 0.1 μm thickness), and a p-type AlGaN cladding layer on the light emitting layer 180 in order. 188 (1.5 μm thickness or less, for example, 0.4 μm thickness) and a p-type GaN contact layer 189 (for example, 0.3 μm thickness) are stacked.

The n-type GaN contact layer 183 and the p-type GaN contact layer 189 are low resistance layers for making ohmic contact with the n-side electrode 173 and the p-side electrode 140, respectively. The n-type GaN contact layer 183 is made an n-type semiconductor by doping GaN with, for example, Si as an n-type dopant at a high concentration (doping concentration is, for example, 3 × 10 ¹⁸ cm ⁻³ ). The p-type AlGaN contact layer 189 is formed as a p-type semiconductor layer by doping Mg as a p-type dopant at a high concentration (doping concentration is 3 × 10 ¹⁹ cm ⁻³ , for example).

  The n-type AlGaN cladding layer 184 and the p-type AlGaN cladding layer 188 have a light confinement effect that confines light from the light emitting layer 180 therebetween.

The n-type AlGaN cladding layer 184 is made an n-type semiconductor by doping AlGaN with, for example, Si as an n-type dopant (doping concentration is, for example, 1 × 10 ¹⁸ cm ⁻³ ). The p-type AlGaN cladding layer 188 is made into a p-type semiconductor layer by doping Mg as a p-type dopant (doping concentration is, for example, 1 × 10 ¹⁹ cm ⁻³ ). The n-type AlGaN cladding layer 184 has a wider band gap than the n-type GaN guide layer 185, and the p-type AlGaN cladding layer 188 has a wider band gap than the p-type GaN guide layer 187. Thereby, good confinement can be performed, and a low threshold and high efficiency semiconductor laser diode can be realized.

  The light emitting layer 180 has, for example, an MQW structure containing InGaN, and is a layer for generating light by recombination of electrons and holes and amplifying the generated light. Specifically, the light emitting layer 180 is configured by alternately laminating an InGaN layer (for example, 3 nm thickness) and a GaN layer (for example, 9 nm thickness) alternately for a plurality of periods. In this case, since the InGaN layer has an In composition ratio of 5% or more, the band gap becomes relatively small, and a quantum well layer is formed. On the other hand, the GaN layer functions as a barrier layer (barrier layer) having a relatively large band gap. For example, the InGaN layer and the GaN layer are alternately and repeatedly stacked for 2 to 7 periods to form the light emitting layer 180 having an MQW structure. The emission wavelength is set to 400 nm to 550 nm by adjusting the composition of In in the quantum well layer (InGaN layer). In the MQW structure, the number of quantum wells containing In is preferably 3 or less.

  A part of the p-type semiconductor layer 182 is removed to form a ridge stripe 120. More specifically, a part of the p-type contact layer 189, the p-type AlGaN cladding layer 188, and the p-type GaN guide layer 187 is removed by etching to form a ridge stripe 120 having a substantially trapezoidal shape (mesa shape) in cross section. ing. The ridge stripe 120 is formed along the c-axis direction.

  The group III nitride semiconductor multilayer structure 172 has a pair of resonator end faces 191 and 192 (cleavage planes) formed by cleavage at both longitudinal ends of the ridge stripe 120. The pair of resonator end faces 191 and 192 are parallel to each other, and both are perpendicular to the c-axis.

  The n-type GaN guide layer 185, the light emitting layer 180, and the p-type GaN guide layer 187 form a Fabry-Perot resonator having the resonator end surfaces 191 and 192 as the resonator end surfaces.

  That is, light generated in the light emitting layer 180 is amplified by stimulated emission while reciprocating between the resonator end faces 191 and 192. A part of the amplified light is extracted from the resonator end faces 191 and 192 as laser light to the outside of the element.

The n-side electrode 173 is made of, for example, Al metal, and the p-side electrode 140 is made of, for example, Al metal or a Pd / Au alloy, and is ohmically connected to the p-type contact layer 189 and the GaN single crystal substrate 171, respectively. The exposed surfaces of the n-type GaN guide layer 187 and the p-type AlGaN cladding layer 188 are covered so that the p-side electrode 140 contacts only the p-type GaN contact layer 189 on the top surface (stripe-shaped contact region) of the ridge stripe 120. An insulating layer 176 is provided. As a result, current can be concentrated on the ridge stripe 120, so that efficient laser oscillation is possible. Further, since the surface of the ridge stripe 120 is protected by covering the region excluding the contact portion with the p-side electrode 140 with the insulating layer 176, the lateral light confinement can be moderated to facilitate the control. In addition, leakage current from the side surface can be prevented. The insulating layer 176 can be made of an insulating material having a refractive index greater than 1, for example, SiO ₂ or ZrO ₂ .

  Further, the top surface of the ridge stripe 120 is an m-plane, and a p-side electrode 140 is formed on the m-plane. The back surface of the GaN single crystal substrate 171 on which the n-side electrode 173 is formed is also m-plane. As described above, since both the p-side electrode 140 and the n-side electrode 173 are formed on the m-plane, it is possible to realize reliability that can sufficiently withstand high-power laser and high-temperature operation.

  The resonator end faces 191 and 192 are respectively covered with an insulating film (not shown in FIG. 17). The resonator end surface 191 is a + c-axis side resonator end surface, and the resonator end surface 192 is a −c-axis side resonator end surface. That is, the crystal face of the resonator end face 191 is a + c plane, and the crystal face of the resonator end face 192 is a −c plane. The insulating film on the −c plane side can function as a protective film that protects the chemically weak −c plane such as being dissolved in alkali, and contributes to improving the reliability of the GaN-based stripe-type LD 170.

  A schematic bird's-eye view configuration example of another GaN-based stripe LD applicable to the semiconductor laser according to the first embodiment is expressed as shown in FIG.

  Another GaN-based stripe LD applied to the semiconductor laser according to the first embodiment is arranged on the nitride semiconductor laser body 270 and the nitride semiconductor laser body 270, as schematically shown in FIG. Laser stripe 280, nitride semiconductor laser body 270 and oxygen absorption layer 250 disposed on laser beam emission end face 200 of laser stripe 280, and laser beam emission end face of nitride semiconductor laser body 270 and laser stripe 280 200 and a rear end face protective film 260 disposed on the opposite side opposite to 200. Here, the nitride semiconductor laser body 270 may be configured similarly to the configuration of FIG.

  As shown in FIG. 18, the oxygen absorbing layer 250 and the rear end surface protective film 260 are arranged so as to cover both end surfaces of the nitride semiconductor laser main body 270 and the laser stripe 280 in common.

The oxygen absorption layer 250 is made of ZrO ₂ , Al ₂ O ₃ , SiO ₂ , TiO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , AlN, SiN, AlON, SiON, AlN _x (0 <x <1). Including.

The rear end face protective film 260 is any one of ZrO ₂ , Al ₂ O ₃ , SiO ₂ , TiO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , AlN, SiN, AlON, SiON, AlN _x (0 <x <1). It is formed by the multilayer film containing. Here, AlN _x (0 <x <1) indicates a case where the composition ratio deviates from the stoichiometry control of AlN.

  As the mounting structure of the GaN-based stripe LD described above, the configurations of FIGS. 2 to 3 or FIGS. 5 to 6 can be applied.

  According to the first embodiment, it is possible to provide a stripe-type semiconductor laser that can be easily packaged thinly and a manufacturing method thereof by wireless connection.

[Second Embodiment]
A schematic bird's-eye view configuration of the semiconductor laser 2 according to the second embodiment is expressed as shown in FIG. The semiconductor laser 2 according to the second embodiment includes a surface emitting LD having a surface emitting region 100 instead of the stripe LD. In the semiconductor laser 2 according to the second embodiment, a cavity resonator associated with laser oscillation is formed in a direction perpendicular to the crystal growth surface, the surface light emitting region 100 is used as an opening, and the laser beam hν is As shown in FIG.

  As shown in FIG. 19, the semiconductor laser 2 according to the second embodiment is disposed on the substrate 10, the first conductivity type cladding layer 14 disposed on the substrate 10, and the first conductivity type cladding layer 14. Active layer 16, second conductivity type cladding layer 18 disposed on active layer 16, surface electrode layer 20 disposed on second conductivity type cladding layer 18, and disposed on the back surface of substrate 10. The back electrode layer 22 is formed along the first side surface 42 a of the substrate 10, the first conductivity type cladding layer 14, the active layer 16, and the second conductivity type cladding layer 18, and the first side surface 42 a and the surface of the surface electrode layer 20. A first insulating layer 24a disposed extending on the top and back electrode layers 22, and a first electrode layer 26A disposed on the first insulating layer 24a and part of the front electrode layer 20 Prepare.

  As shown in FIG. 19, in the semiconductor laser 2 according to the second embodiment, the surface electrode layer 20 includes a surface emitting region 100, and the surface emitting region is provided from the active layer 16 via the second conductivity type cladding layer 18. A laser beam hν is emitted along 100.

  The surface electrode layer 20 includes a surface emitting region 100, and emits laser light along the surface emitting region 100 from the active layer 16 through the second conductivity type cladding layer 18.

  The first electrode layer may include a thin film metal layer or a transparent electrode layer.

  In the above, the 1st side 42a does not necessarily need to be constituted by a cleavage plane. Similarly, the second side surface 42b facing the first side surface 42a does not necessarily have to be a cleavage plane.

  Since the semiconductor laser 2 according to the second embodiment is a surface emitting semiconductor laser, the material of the surface electrode layer 20 is preferably a transparent conductive film. For example, a thin titanium layer and an Au layer can be used. Alternatively, it can be formed using ITO, IZTO, ZnO, or the like. The back electrode layer 22 is formed of, for example, an Au layer.

  The other configuration is the same as that of the first embodiment, and a duplicate description is omitted.

(Production method)
The manufacturing method of the semiconductor laser 2 according to the second embodiment includes a step of forming the first conductivity type cladding layer 14 on the substrate 10 and a step of forming the active layer 16 on the first conductivity type cladding layer 14. The step of forming the second conductivity type cladding layer 18 on the active layer 16, the step of forming the surface electrode layer 20 on the second conductivity type cladding layer 18, and the formation of the back electrode layer 22 on the back surface of the substrate 10. Along the first side surface 42 a of the substrate 10, the first conductivity type cladding layer 14, the active layer 16, and the second conductivity type cladding layer 18, and on the surface of the first side surface 42 a and the surface electrode layer 20, and the back electrode A step of extending the surface of the layer 22 to form the first insulating layer 24a, and a step of forming the first electrode layer 26A on the first insulating layer 24a and part of the surface electrode layer 20;

  In addition, the manufacturing method of the semiconductor laser 2 according to the second embodiment includes a step of forming the anode electrode pattern 30A on the semiconductor mounting substrate 32S, a step of forming the insulating layer 30I on the semiconductor mounting substrate 32S, The step of forming the cathode electrode pattern 30K on the layer 30I, the step of forming the cathode electrode 28 on the cathode electrode pattern 30K, and the first electrode layer 26A on the semiconductor mounting substrate 32S are mounted on the anode electrode pattern 30A. And placing the back electrode layer 22 on the cathode electrode pattern 30K.

  The method for manufacturing the semiconductor laser 2 according to the second embodiment includes a step of forming the anode electrode pattern 30A on the insulating mounting substrate 32I, a step of forming the cathode electrode pattern 30K on the insulating mounting substrate 32I, The step of forming the cathode electrode 28 on the cathode electrode pattern 30K, and the first electrode layer 26A is placed on the anode electrode pattern 30A on the insulating mounting substrate 32I, and the back electrode layer 22 is placed on the cathode electrode pattern 30K. It may have a process of mounting on.

  In the method of manufacturing the semiconductor laser 2 according to the second embodiment, the wafer process steps are expressed in the same way as in FIGS. 8A to 8D. Further, a schematic bird's-eye view structure showing a state where the LD wafer 34 is scribed along the scribe surface, and a schematic bird's-eye view structure of a plurality of LD bars 36 formed by scribing the LD wafer 34 along the scribe surface are respectively It is expressed in the same manner as in FIGS. 9A and 9B. In the manufacturing method of the semiconductor laser 2 according to the second embodiment, the other manufacturing steps are the same as those in the first embodiment, and thus the duplicate description is omitted.

(GaAs surface emitting LD)
A schematic bird's-eye view configuration example of a GaAs surface emitting LD applicable to the semiconductor laser according to the second embodiment is expressed as shown in FIG.

As shown in FIG. 20, the GaAs surface emitting LD applied to the semiconductor laser according to the second embodiment is provided on the substrate 310, the substrate 310, the Al _a Ga _1-a As layer, and the Al _b. An n-type (first conductivity type) DBR 320 formed by alternately laminating Ga _1-b As layers (a <b <1), an n-type cladding layer 330 provided on the n-type DBR 320, a first Active layer 332 provided on conductive clad layer 330, p-type (second conductive type) clad layer 334 provided on active layer 332, n-type clad layer 330, active layer 332, and p-type clad The layer 334 is provided so as to be sandwiched between the first conductivity type DBRs, and includes a p-type DBR 350 formed by alternately laminating Al _a Ga _1-a As layers and Al _b Ga _1-b As layers. The total film thickness of each of the n-type DBR 320 and the p-type DBR 350 is, for example, an optical distance of about ½ of the laser oscillation wavelength, and the film thickness of the Al _a Ga _1-a As layer is the Al _b Ga _1-b As layer. It is configured to be thinner than the film thickness.

  The substrate 310 is, for example, an n-type GaAs substrate doped with Si as an n-type dopant.

The n-type DBR 320 is formed by alternately laminating Al _a Ga _1-a As layers and Al _b Ga _1-b As layers (a <b <1) so that the number of pairs is about 50 to 80. . The p-type DBR 350 is formed by alternately laminating Al _a Ga _1-a As layers and Al _b Ga _1-b As layers (a <b <1) so that the number k of pairs is about 30-50. The The Al composition ratio a of the Al _a Ga _1-a As layer is preferably 45% ≦ a ≦ 50%. If the Al composition ratio is 45% or less, the absorption coefficient increases at the laser oscillation wavelength (660 nm) and absorbs light, and it is not preferable, and if it is 50% or more, it is not preferable for obtaining a high resonator reflectance. . The Al composition ratio b of the Al _b Ga _1-b As layer is preferably 90% ≦ b ≦ 95%. When the Al composition ratio of the Al _b Ga _1-b As layer is outside the above range, the refractive index difference between the two semiconductor layers becomes small and a high reflectance cannot be obtained. Unfavorable to get rate.

The thicknesses of the semiconductor layers constituting the n-type DBR 320 and the p-type DBR 350 are determined so as to have a low thermal resistance and a high reflectance. Therefore, in order to obtain a low thermal resistance and a high reflectance, the Al _a Ga _1-a As layer of the semiconductor layers constituting the n-type DBR 320 and the p-type DBR 350 has a film thickness of 3/20 of the laser oscillation wavelength. It is preferably thicker than the optical distance and thinner than 1/4 of the laser oscillation wavelength.

  Regarding the reflectivity of the n-type DBR 320 and the p-type DBR 350, since the layers constituting the n-type DBR 320 and the p-type DBR 350 are Al-containing semiconductor layers, the refractive index decreases as the Al composition ratio increases and the gap becomes wide. . Therefore, in order for the n-type DBR 320 and the p-type DBR 350 to obtain high reflectivity, the thickness of the semiconductor layer having a large Al composition ratio among the layers constituting the n-type DBR 320 and the p-type DBR 350 is reduced as much as possible. It is preferable.

  The n-type cladding layer 330 is made of, for example, InGaAlP doped with Si as an n-type dopant. An n-type light guide layer (not shown) made of InGaAlP doped with Si as an n-type dopant and having a function of adjusting the light density in the active layer 332 may be provided on the n-type cladding layer 330. Absent.

  In the active layer 332, electrons supplied from the n-type cladding layer 330 and holes supplied from the p-type cladding layer 334 are recombined to generate light. In the active layer 332, for example, a well layer is sandwiched between barrier layers having a band gap larger than that of the well layer (a QW structure can be used. Note that this quantum well structure does not have one well layer. The active layer 332 may be MQW, and the active layer 332 that is an MQW may have a structure in which 2 to 4 pairs of InGaAlP and InGaP are alternately stacked. For example, a p-type light guide layer (not shown) made of InGaAlP doped with Mg as a p-type dopant and having a role of adjusting the light density in the active layer 332 can be provided.

  The p-type cladding layer 334 is made of, for example, InGaAlP doped with Mg as a p-type dopant. An oxidized constricting layer 340 is provided on the p-type cladding layer 334. The oxidized constricting layer 340 is a layer having a current confinement structure in order to allow a current to selectively flow through a region serving as a waveguide. As an example, the oxidized constricting layer 340 is provided on the p-type cladding layer 334 as shown in FIG. 20, but may be provided between the active layer 332 and the p-side contact layer. The current confinement structure of the oxidation confinement layer 340 can be formed by selectively oxidizing aluminum composition layers having different oxidation rates.

  The GaAs surface emitting LD applicable to the semiconductor laser according to the second embodiment further includes a cathode electrode 360 that applies a voltage to the n-type cladding layer 330 and an anode that applies a voltage to the p-type cladding layer 334. An electrode 362 is provided. As shown in FIG. 20, the cathode electrode 360 is disposed on the back side of the substrate 310, and the anode electrode 362 is disposed on the surface of the p-type DBR 350. The cathode electrode 360 is made of, for example, Al metal, and the anode electrode 362 is made of, for example, a palladium (Pd) -gold (Au) alloy. The anode electrode 362 has a ring shape and has an opening which is a surface emitting region 100 of laser light having an aperture diameter of about 8 μm to 25 μm. The cathode electrode 360 and the anode electrode 362 are ohmically connected to the substrate 310 and the p-type DBR 350, respectively. Note that an n-type n-side contact layer may be disposed between the substrate 310 and the cathode electrode 360. A p-type p-side contact layer may be disposed between the p-type DBR 350 and the anode electrode 362.

  According to the second embodiment, by adopting the wireless connection configuration, it is not necessary to perform wire bonding on the surface electrode when the element is assembled, and the light extraction efficiency from the upper part of the element is improved. In addition, a thin package can be realized.

  The mounting structure of the above-described GaAs-based surface-emitting type LD can be applied to the configurations shown in FIGS. 2 to 3 or FIGS.

  According to the second embodiment, it is possible to provide a surface-emitting type semiconductor laser that can be easily made into a thin package and a method for manufacturing the same by wireless connection.

[Other embodiments]
As described above, the present invention has been described according to the first to second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the first to second embodiments, examples are disclosed in which the conductivity type of the substrate 10 and the first conductivity type cladding layer 14 is n-type, and the conductivity type of the second conductivity type cladding layer 18 is p-type. However, these conductivity types may be reversed. In this case, the anode electrode and the cathode electrode have opposite configurations, the first electrode layer connected to the front electrode layer 20 is connected to the cathode electrode, and the back electrode layer 22 is connected to the anode electrode.

  The silicon bar 40 is not limited to silicon, and may be a bar formed using other materials.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The semiconductor laser of the present invention can be used for all LDs having a semiconductor mounting substrate or an insulating mounting substrate, and can be applied to a wide range of fields such as an optical memory, a laser printer, a display, illumination, a massively parallel system, and an optical interconnect.

1, 2 ... Semiconductor laser 10 ... Substrate 14 ... First conductivity type cladding layer (n-type cladding layer)
16 ... Active layer (MQW)
18 ... Second conductivity type cladding layer (p-type cladding layer)
DESCRIPTION OF SYMBOLS 20 ... Front electrode layer 22 ... Back electrode layer 24a, 24b ... Insulating layer 26A ... 1st electrode layer 28 ... Cathode electrode 30A ... Anode electrode pattern 30K ... Cathode electrode pattern 30I ... Insulating layer 30S, 44 ... Solder layer 32I ... Insulation mounting Substrate 32S ... Semiconductor mounting substrate 34 ... LD wafer 36 ... LD bar 38 ... LD bar fixing device 40 ... Silicon bars 42a, 42b ... Side surfaces (cleavage surface)
50, 50a ... laminated structure 80 ... laser stripe 90 ... monitor light detecting photodiode 100 ... surface emitting region

Claims (17)

A substrate,
A first conductivity type cladding layer disposed on the substrate;
An active layer disposed on the first conductivity type cladding layer;
A second conductivity type cladding layer disposed on the active layer;
A surface electrode layer disposed on the second conductivity type cladding layer;
A back electrode layer disposed on the back surface of the substrate;
Formed along the first cleaved surface of the substrate, the first conductivity type clad layer, the active layer, and the second conductivity type clad layer, on the surface of the first cleaved surface and the surface electrode layer, and the back electrode A first insulating layer disposed extending over the surface of the layer;
A second insulation formed along a second cleavage surface opposite to the first cleavage surface and extending on the surface of the second cleavage surface, the surface electrode layer, and the surface of the back electrode layer Layers,
And a first electrode layer disposed on a part of the first insulating layer and on the surface electrode layer. The surface electrode layer comprises a laser stripe;
2. The semiconductor laser according to claim 1, wherein a laser beam is emitted from the active layer along the laser stripe through the second insulating layer.   2. The semiconductor laser according to claim 1, wherein the first electrode layer connected to the surface electrode layer is an anode, and the back electrode layer is a cathode. A semiconductor mounting substrate;
An anode electrode pattern disposed on the semiconductor mounting substrate;
A cathode electrode pattern disposed on the semiconductor mounting substrate via an insulating layer, wherein the first electrode layer is mounted on and connected to the anode electrode pattern on the semiconductor mounting substrate, and the back surface 4. The semiconductor laser according to claim 3, wherein the electrode is placed on and connected to the cathode electrode pattern. An insulated mounting board; and
An anode electrode pattern disposed on the insulating mounting substrate;
A cathode electrode pattern disposed on the insulating mounting substrate, wherein the first electrode layer is placed on and connected to the anode electrode pattern on the insulating mounting substrate, and the back electrode is connected to the cathode electrode 4. The semiconductor laser according to claim 3, wherein the semiconductor laser is mounted on and connected to an electrode pattern.   The semiconductor laser according to claim 4, wherein the semiconductor mounting substrate is a silicon substrate.   6. The semiconductor laser according to claim 5, wherein the insulating mounting substrate is an aluminum nitride substrate or an alumina substrate.   2. The semiconductor laser according to claim 1, wherein one or both of the first insulating layer and the second insulating layer includes a distributed black reflective layer.   9. The semiconductor laser according to claim 8, further comprising a monitor light detection photodiode for detecting monitor light emitted from the active layer through the first insulating layer and the first electrode layer.   6. The semiconductor laser according to claim 4, wherein the anode electrode pattern and the first electrode layer, and the cathode electrode pattern and the cathode electrode are soldered. A substrate,
A first conductivity type cladding layer disposed on the substrate;
An active layer disposed on the first conductivity type cladding layer;
A second conductivity type cladding layer disposed on the active layer;
A surface electrode layer disposed on the second conductivity type cladding layer;
A back electrode layer disposed on the back surface of the substrate;
Formed along the first side surface of the substrate, the first conductivity type cladding layer, the active layer, and the second conductivity type cladding layer, on the surface of the first side surface and the surface electrode layer, and on the back electrode layer A first insulating layer disposed extending on the surface;
And a first electrode layer disposed on a part of the first insulating layer and on the surface electrode layer. The surface electrode layer includes a surface emitting region,
12. The semiconductor laser according to claim 11, wherein a laser beam is emitted from the active layer along the surface emitting region through the second conductivity type cladding layer.   The semiconductor laser according to claim 11, wherein the first electrode layer includes a thin metal layer or a transparent electrode layer. Forming a first conductivity type cladding layer on a substrate;
Forming an active layer on the first conductivity type cladding layer;
Forming a second conductivity type cladding layer on the active layer;
Forming a surface electrode layer on the second conductivity type cladding layer;
Forming a back electrode layer on the back surface of the substrate;
Along the first cleavage surface of the substrate, the first conductivity type cladding layer, the active layer, and the second conductivity type cladding layer, on the surface of the first cleavage surface and the surface electrode layer, and on the back electrode layer Extending a surface to form a first insulating layer;
A step of forming a second insulating layer extending along the second cleaved surface facing the first cleaved surface, on the surface of the second cleaved surface, the surface electrode layer, and the surface of the back electrode layer When,
Forming a first electrode layer on a part of the first insulating layer and on the surface electrode layer. A method of manufacturing a semiconductor laser, comprising: Forming a first conductivity type cladding layer on a substrate;
Forming an active layer on the first conductivity type cladding layer;
Forming a second conductivity type cladding layer on the active layer;
Forming a surface electrode layer on the second conductivity type cladding layer;
Forming a back electrode layer on the back surface of the substrate;
Along the first side surface of the substrate, the first conductivity type cladding layer, the active layer, and the second conductivity type cladding layer, on the surface of the first side surface and the surface electrode layer, and on the surface of the back electrode layer Extending to and forming a first insulating layer;
Forming a first electrode layer on a part of the first insulating layer and on the surface electrode layer. A method of manufacturing a semiconductor laser, comprising: Forming an anode electrode pattern on a semiconductor mounting substrate;
Forming an insulating layer on the semiconductor mounting substrate;
Forming a cathode electrode pattern on the insulating layer;
The method includes: placing the first electrode layer on the anode electrode pattern and placing the back electrode layer on the cathode electrode pattern on the semiconductor mounting substrate. A method for manufacturing a semiconductor laser according to 14 or 15. Forming an anode electrode pattern on the insulating mounting substrate;
Forming a cathode electrode pattern on the insulating mounting substrate;
The method includes: placing the first electrode layer on the anode electrode pattern and placing the back electrode layer on the cathode electrode pattern on the insulating mounting substrate. A method for manufacturing a semiconductor laser according to 14 or 15.

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