JP5170406B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device.

In recent years, a laser device having high luminance and excellent color reproducibility is expected as a light emitting device for a light source of a display device such as a projector or a display. However, speckle noise generated by irregularly reflected light on the screen surface may be a problem. For example, Japanese Patent Application Laid-Open Publication No. 2004-228620 proposes a method for reducing speckle noise by changing the speckle pattern by swinging the screen.
Japanese Patent Laid-Open No. 11-64789

  However, in the method disclosed in Patent Document 1, the screen is limited, a member such as a motor for moving the screen is required, and noise is generated from the motor or the like. Problems may occur.

  In order to reduce speckle noise, it is also conceivable to use a general LED (Light Emitting Diode) as a light emitting device for a light source. However, there are cases where a sufficient light output cannot be obtained with an LED.

  One object of the present invention is to provide a light-emitting device having a novel light-emitting element that can reduce speckle noise and has high output.

The light emitting device according to the present invention is
Mounting module;
A light emitting device mounted above the mounting module;
Including
The light emitting element is
A cladding layer;
An active layer formed above the cladding layer;
Another cladding layer formed above the active layer;
Have
At least a part of the active layer constitutes a gain region,
The gain region is provided in a direction inclined with respect to a normal to the first side surface from the first side surface to the second side surface of the active layer in a plan view.
The mounting module is
A first reflecting surface that reflects the first emitted light emitted from the first end surface on the first side surface side of the gain region toward the upper side of the light emitting element;
A second reflecting surface that reflects the second emitted light emitted from the second end surface on the second side surface of the gain region toward the upper side of the light emitting element;
Have

  In the light emitting element included in the light emitting device according to the present invention, as will be described later, laser oscillation of light generated in the gain region can be suppressed or prevented. Therefore, speckle noise can be reduced. Furthermore, in the light emitting device according to the present invention, the light generated in the gain region can travel while receiving a gain in the gain region and be emitted to the outside. Therefore, it is possible to obtain a higher output than conventional general LEDs. As described above, according to the present invention, it is possible to provide a light-emitting device having a novel light-emitting element that can reduce speckle noise and has high output.

  In the description of the present invention, the word “upper” is referred to as, for example, another specific member (hereinafter referred to as “B member”) formed “above” a “specific member (hereinafter referred to as“ A member ”). ) "Etc. In the description according to the present invention, in this case, the B member is formed directly on the A member, and the B member is formed on the A member via another member. The word “above” is used as a case where the case is included.

In the light emitting device according to the present invention,
The traveling direction of the first reflected light by the first reflecting surface and the traveling direction of the second reflected light by the second reflecting surface can be the same.

In the light emitting device according to the present invention,
The traveling direction of the first reflected light and the traveling direction of the second reflected light may be vertically upward with respect to the upper surface of the active layer.

In the light emitting device according to the present invention,
The direction in which the first emitted light travels is perpendicular to the line of intersection between the surface parallel to the upper surface of the active layer and the first reflecting surface when viewed in a plane.
The traveling direction of the second emitted light may be perpendicular to the line of intersection between the surface parallel to the upper surface of the active layer and the second reflecting surface in plan view.

In the light emitting device according to the present invention,
In the gain region, the first end surface and the second end surface may not overlap each other when viewed in plan from the first side surface side.

In the light emitting device according to the present invention,
An electrode electrically connected to the cladding layer;
Another electrode electrically connected to the other cladding layer;
Can have.

  In the description according to the present invention, the phrase “electrically connected” is used as, for example, another specific member (hereinafter “electrically connected” to “specific member (hereinafter referred to as“ C member ”)”. It is used as "D member"). In the description according to the present invention, in the case of this example, the case where the C member and the D member are directly connected and electrically connected, and the C member and the D member are the other members. The term “electrically connected” is used as a case where the case where the terminals are electrically connected to each other is included.

In the light emitting device according to the present invention,
A plurality of the gain regions are provided,
Each of the first reflecting surfaces with respect to the first end surface of the plurality of gain regions constitutes one plane as a whole,
Each of the second reflecting surfaces with respect to the second end surface of the plurality of gain regions may constitute one plane as a whole.

In the light emitting device according to the present invention,
A plurality of the gain regions are provided,
Each of the first reflecting surfaces with respect to the first end surface of the plurality of gain regions is provided at a position where the optical path lengths from the first end surface of the first emitted light to the first reflecting surface are the same,
Each of the second reflective surfaces with respect to the second end surface of the plurality of gain regions is provided at a position where the optical path lengths from the second end surface to the second reflective surface of the second emitted light are the same. be able to.

In the light emitting device according to the present invention,
The reflectivity of each of the first reflective surface and the second reflective surface may be higher than 50% and 100% or lower.

In the light emitting device according to the present invention,
The mounting module has a support member that supports the light emitting element,
The support member may have a thermal conductivity higher than that of the light emitting device.

In the light emitting device according to the present invention,
The active layer may be provided on the mounting module side of the light emitting element.

In the light emitting device according to the present invention,
Including a sealing member for sealing the light emitting element,
The first reflected light and the second reflected light can pass through the sealing member.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

1. 1. First embodiment 1.1. First, the light emitting device 1000 according to the first embodiment will be described.

  1 is a plan view schematically showing the light emitting device 1000, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1 and 3, the sealing member 148 is not shown for convenience. In FIG. 2, the light emitting element 100 is simplified for convenience.

  As illustrated in FIGS. 1 to 3, the light emitting device 1000 includes a mounting module 160 and a light emitting element 100. The light emitting device 1000 can further include, for example, an insulating member 146, a terminal 144, a first connection member 142, a second connection member 143, and a sealing member 148. Here, a case where the light emitting element 100 is an InGaAlP-based (red) semiconductor light emitting element will be described.

  The light emitting element 100 is mounted on the mounting module 160. As shown in FIGS. 1 to 3, the light emitting device 100 includes a clad layer (hereinafter referred to as “first clad layer”) 110, an active layer 108 formed thereon, and a clad layer ( (Hereinafter referred to as “second cladding layer”) 106. The light emitting element 100 further includes, for example, a substrate 102, a buffer layer 104, a contact layer 112, an electrode (hereinafter referred to as “first electrode”) 122, and an electrode (hereinafter referred to as “second electrode”) 120. Can have.

  As the substrate 102, for example, a first conductivity type (for example, n-type) GaAs substrate or the like can be used.

  The buffer layer 104 can be formed under the substrate 102 as shown in FIG. 3, for example. The buffer layer 104 can improve the crystallinity of a layer formed above the buffer layer 104, for example, in an epitaxial growth step described later (see FIG. 5). As the buffer layer 104, for example, a first conductivity type (n-type) GaAs layer, InGaP layer, or the like having better crystallinity (for example, lower defect density) than the substrate 102 can be used.

  The second cladding layer 106 is formed under the buffer layer 104. The second cladding layer 106 is made of, for example, a first conductivity type semiconductor. As the second cladding layer 106, for example, an n-type AlGaP layer can be used.

  The active layer 108 is formed under the second cladding layer 106. The active layer 108 is provided on the mounting module 160 side of the light emitting element 100, for example. In other words, the active layer 108 is provided, for example, on the light emitting element 100 below the middle in the thickness direction (on the side opposite to the substrate 102 side). The active layer 108 has, for example, a multiple quantum well (MQW) structure in which three quantum well structures each composed of an InGaP well layer and an InGaAlP barrier layer are stacked.

  A part of the active layer 108 constitutes a gain region 180. The gain region 180 can generate light, and this light can receive gain within the gain region 180. The shape of the active layer 108 is, for example, a rectangular parallelepiped (including a cube). The active layer 108 has a first side surface 107 and a second side surface 109 as shown in FIG. The first side surface 107 and the second side surface 109 face each other, for example, and are parallel, for example.

  The gain region 180 is provided from the first side surface 107 to the second side surface 109 in a direction inclined with respect to the normal line P of the first side surface 107 when viewed in plan (see FIG. 1). Thereby, laser oscillation of light generated in the gain region 180 can be suppressed or prevented. Note that the case where the gain region 180 is provided in a certain direction means that the direction corresponds to the center of the first end surface 170 on the first side face 107 side of the gain region 180 and the second direction when viewed in plan. This refers to the case where it coincides with the direction connecting the center of the second end surface 172 on the side surface 109 side.

  FIG. 4 is a plan view of the active layer 108 in the example of FIGS. 1 to 3 as seen from the first side face 107 side. In the gain region 180 according to the present embodiment, as shown in FIG. 4, the first end surface 170 on the first side surface 107 side and the second end surface 172 on the second side surface 109 side do not overlap. As a result, light generated in the gain region 180 can be prevented from being directly subjected to multiple reflection between the first end surface 170 and the second end surface 172. As a result, since a direct resonator cannot be formed, laser oscillation of light generated in the gain region 180 can be more reliably suppressed or prevented. Therefore, the light emitting element 100 can emit light that is not laser light. In this case, as shown in FIG. 4, the shift width x between the first end face 170 and the second end face 172 may be a positive value in the gain region 180.

  In the illustrated example, as shown in FIG. 1, the width a of the first end face 170 of the gain region 180 is the same as the width b of the second end face 172, but may be different. The planar shape of the gain region 180 is, for example, a parallelogram as shown in FIG.

  The first cladding layer 110 is formed under the active layer 108. The first cladding layer 110 is made of, for example, a second conductivity type (eg, p-type) semiconductor. As the first cladding layer 110, for example, a p-type AlGaP layer can be used.

  For example, the p-type first cladding layer 110, the active layer 108 not doped with impurities, and the n-type second cladding layer 106 constitute a pin diode. Each of the first cladding layer 110 and the second cladding layer 106 is a layer having a larger forbidden band width and a smaller refractive index than the active layer 108. The active layer 108 has a function of amplifying light. The first cladding layer 110 and the second cladding layer 106 have a function of confining injected carriers (electrons and holes) and light with the active layer 108 interposed therebetween.

  The contact layer 112 can be formed under the first cladding layer 110, for example, as shown in FIG. As the contact layer 112, a layer in ohmic contact with the first electrode 122 can be used. The contact layer 112 is made of, for example, a second conductivity type semiconductor. As the contact layer 112, for example, a p-type GaAs layer can be used.

  The first electrode 122 is formed under the contact layer 112. The first electrode 122 is electrically connected to the first cladding layer 110 via the contact layer 112. The first electrode 122 is one electrode for driving the light emitting element 100. As the first electrode 122, for example, a layer in which a Cr layer, an AuZn layer, and an Au layer are stacked in this order from the contact layer 112 side can be used. The upper surface of the first electrode 122 has a planar shape similar to that of the gain region 180. In the illustrated example, the current path between the electrodes 122 and 120 is determined by the planar shape of the contact surface between the first electrode 122 and the contact layer 112, and as a result, the planar shape of the gain region 180 can be determined. . Although not shown, for example, the contact surface between the second electrode 120 and the substrate 102 may have the same planar shape as the gain region 180.

  The second electrode 120 is formed on the entire surface of the substrate 102. The second electrode 120 can be in contact with a layer that is in ohmic contact with the second electrode 120 (the substrate 102 in the illustrated example). The second electrode 120 is electrically connected to the second cladding layer 106 through the substrate 102 and the buffer layer 104. The second electrode 120 is the other electrode for driving the light emitting element 100. As the second electrode 120, for example, a layer in which a Cr layer, an AuGe layer, a Ni layer, and an Au layer are stacked in this order from the substrate 102 side can be used. In addition, a second contact layer (not shown) is provided between the second cladding layer 106 and the buffer layer 104, and the second cladding layer 106 side of the second contact layer is exposed by dry etching or the like. The electrode 120 can also be provided under the second contact layer. Thereby, a single-sided electrode structure can be obtained. For example, an n-type GaAs layer can be used as the second contact layer. Although not shown, the substrate 102 and a member provided thereunder can be separated using, for example, an epitaxial lift-off (ELO) method, a laser lift-off method, or the like. That is, the light emitting element 100 may not have the substrate 102. In this case, for example, the second electrode 120 can be formed directly on the buffer layer 104.

  In the light emitting element 100, when a forward bias voltage of a pin diode is applied between the first electrode 122 and the second electrode 120, recombination of electrons and holes occurs in the gain region 180 of the active layer 108. This recombination causes light emission. Starting from this generated light, stimulated emission occurs in a chain, the light travels in the gain region 180, the light intensity is amplified in the meantime, and is emitted from the first end face 170 as the first outgoing light L1, and the second The light can be emitted from the end surface 172 as the second emitted light L2. The first emitted light L1 and the second emitted light L2 can be emitted in a direction further inclined than the inclination of the gain region 180 with respect to the perpendicular P of the first side surface 107, for example, due to light refraction.

  As illustrated in FIGS. 1 and 2, the mounting module 160 includes a first reflecting surface 162 and a second reflecting surface 164. The mounting module 160 can further include, for example, a first support member 140, a second support member 141, and a reflection portion 163.

  As shown in FIG. 2, the first reflecting surface 162 can reflect the first emitted light L <b> 1 toward the upper side of the light emitting element 100. Similarly, the second reflecting surface 164 can reflect the second emitted light L2 toward the upper side of the light emitting element 100. The first emitted light L1 is reflected by the first reflecting surface 162, and can travel, for example, vertically upward (Z direction in FIG. 1) with respect to the upper surface of the active layer 108 as the first reflected light L3. The direction in which the first emitted light L1 travels and the direction in which the first reflected light L3 travels form, for example, a right angle. Similarly, the second emitted light L2 is reflected by the second reflecting surface 164, and can travel vertically upward as the second reflected light L4 with respect to the upper surface of the active layer 108, for example. The direction in which the second emitted light L2 travels and the direction in which the second reflected light L4 travels form, for example, a right angle. Further, for example, in the illustrated example, the traveling direction of the first reflected light L3 by the first reflecting surface 162 and the traveling direction of the second reflected light L4 by the second reflecting surface 164 are the same. The reflectance of the first reflecting surface 162 with respect to the first outgoing light L1 is preferably higher than 50% and not higher than 100%. Similarly, the reflectance of the second reflecting surface 164 with respect to the second emitted light L2 is preferably higher than 50% and not higher than 100%.

  For example, as shown in FIG. 1, the traveling direction of the first emitted light L <b> 1 is perpendicular to an intersection line V between a plane parallel to the upper surface of the active layer 108 (XY plane) and the first reflecting surface 162. It is made. Similarly, the traveling direction of the second outgoing light L2 is, for example, perpendicular to the intersecting line W between the surface parallel to the upper surface of the active layer 108 and the second reflecting surface 164.

  For example, the first support member 140 can indirectly support the light emitting element 100 via the second support member 141. As the 1st support member 140, what provided the recessed part 145 in the plate-shaped (cuboid shape) member can be used, for example. The side surface of the recess 145 can be inclined, for example, 45 degrees with respect to the horizontal direction (the XY direction in FIG. 1). The number of side surfaces of the recess 145 is, for example, four. For example, the light emitting element 100 is surrounded by four side surfaces of the recess 145.

  The second support member (submount) 141 can directly support the light emitting element 100, for example. As shown in FIGS. 1 to 3, the second support member 141 is formed on the bottom surface of the concave portion 145 of the first support member 140. The light emitting element 100 is formed on the second support member 141. As the second support member 141, for example, a plate-like member can be used. For example, the first support member 140 may directly support the light emitting element 100 without providing the second support member 141.

  For example, the thermal conductivity of the first support member 140 is higher than the thermal conductivity of the second support member 141, and the thermal conductivity of the second support member 141 is higher than the thermal conductivity of the light emitting element 100, for example. The thermal conductivity of each of the support members 140 and 141 is, for example, 140 W / mK or more. Each of the support members 140 and 141 is made of, for example, Cu, Al, Mo, W, Si, C, Be, Au, a compound thereof (for example, AlN, BeO), an alloy (for example, CuMo), or the like. Can do. In addition, each of the support members 140 and 141 can be configured from a combination of these examples, for example, a multilayer structure of a copper (Cu) layer and a molybdenum (Mo) layer.

  The reflection part 163 may be formed on the side surface of the recess 145 of the first support member 140. Since the reflection part 163 is formed along the inclined side surface of the recess 145, the reflection part 163 is also inclined. Of the surface of the reflector 163, the surface on which the first outgoing light L1 is incident is the first reflective surface 162, and the surface on which the second outgoing light L2 is incident is the second reflective surface 164. The reflector 163 can be made of, for example, Al, Ag, Au, or the like. By providing the reflecting portion 163, the reflectance of the reflecting surfaces 162 and 164 can be increased. Note that, for example, the inclined side surfaces of the recesses 145 of the first support member 140 can be used as the first reflecting surface 162 and the second reflecting surface 164 without providing the reflecting portion 163.

  As shown in FIGS. 1 and 3, for example, a cylindrical through hole 147 is formed in the first support member 140. In the through hole 147, for example, a columnar terminal 144 whose side surface is covered with an insulating member 146 is provided. The insulating member 146 is made of, for example, resin, ceramics (for example, AlN). The terminal 144 is made of, for example, copper (Cu).

  The terminal 144 is connected to the second electrode 120 of the light emitting element 100 by a first connection member 142 such as a bonding wire, for example. The first connecting member 142 is provided so as not to block the optical paths of the emitted lights L1 and L2. Further, the first electrode 122 of the light emitting element 100 is connected to the second support member 141 by a second connection member 143 such as a plating bump, for example. The second support member 141 is connected to the first support member 140. Therefore, a voltage can be applied between the first electrode 122 and the second electrode 120 by applying different potentials to the terminal 144 and the first support member 140.

  For example, as illustrated in FIG. 2, the sealing member 148 is provided on the mounting module 160. For example, the sealing member 148 can seal the light emitting element 100 provided in the recess 145 by sealing the recess 145 of the first support member 140. The sealing member 148 is made of a material that is transmissive to the wavelengths of the reflected lights L3 and L4. Thereby, at least a part of the first reflected light L3 can pass through the sealing member 148, and at least a part of the second reflected light L4 can pass through the sealing member 148. . The sealing member 148 can be made of, for example, quartz, glass, quartz, plastic, or the like. These can be appropriately selected according to the wavelengths of the reflected lights L3 and L4. Thereby, the absorption loss of light can be reduced.

  The light emitting device 1000 according to the present embodiment can be applied to a light source such as a projector, a display, a lighting device, and a measurement device. The same applies to the embodiments described later.

  1.2. Next, an example of a method for manufacturing the light emitting device 1000 according to the first embodiment will be described with reference to the drawings, but is not limited to the following example.

  5 to 8 are cross-sectional views schematically showing a manufacturing process of the light-emitting device 1000, FIGS. 5 to 7 correspond to the cross-sectional view shown in FIG. 3, and FIG. 8 is shown in FIG. Corresponds to the sectional view.

  (1) First, as shown in FIG. 5, the buffer layer 104, the second cladding layer 106, the active layer 108, the first cladding layer 110, and the contact layer 112 are epitaxially grown in this order on the substrate 102. As a method for epitaxial growth, for example, MOCVD (Metal-Organic Chemical Vapor Deposition) method, MBE (Molecular Beam Epitaxy) method or the like can be used.

  (2) Next, as shown in FIG. 6, the first electrode 122 is formed on the contact layer 112. The first electrode 122 is formed, for example, by forming a conductive layer on the entire surface by a vacuum deposition method and then patterning the conductive layer using a photolithography technique and an etching technique. The first electrode 122 can also be formed in a desired shape by, for example, a combination of a vacuum deposition method and a lift-off method.

  Next, as shown in FIG. 6, the second electrode 120 is formed under the entire lower surface of the substrate 102. The manufacturing method of the second electrode 120 is the same as the example of the manufacturing method of the first electrode 122 described above, for example. Note that the order of forming the first electrode 122 and the second electrode 120 is not particularly limited.

  (3) The light emitting element 100 of this embodiment is obtained by the above process as shown in FIG. Next, the second connection member 143 can be formed on the first electrode 122 of the light emitting element 100 by, for example, plating.

  (4) Next, the first support member 140 having a desired shape can be produced by, for example, mold molding. Next, as shown in FIG. 7, a through hole 147 is provided in the first support member 140 by a known method. Next, the insulating member 146 is formed so as to cover the inner side surface of the through hole 147. The insulating member 146 is formed so as not to block the through hole 147. The insulating member 146 is formed by, for example, a CVD (Chemical Vapor Deposition) method. Next, a rod-shaped terminal 144 is inserted inside the insulating member 146. A method in which an insulating member 146 formed around the rod-shaped terminal 144 is inserted into the through hole 147 can also be used.

  (5) Next, as shown in FIG. 8, the reflective portion 163 can be formed in a desired region of the first support member 140. The reflective portion 163 can be formed using, for example, an evaporation method by covering a region other than a desired region with a mask such as a photoresist. In addition, formation of the reflection part 163 can also be performed before formation of the said through-hole 147, for example.

  (6) Next, the second support member 141 can be mounted on the first support member 140. Next, as shown in FIG. 3, the light emitting element 100 is turned over, that is, the active layer 108 side of the light emitting element 100 is directed to the mounting module 160 side (junction down), and the light emitting element is attached to the second support member 141. 100 can be flip-chip mounted. Note that the second support member 141 may be mounted on the first support member 140 after the light emitting element 100 is mounted on the second support member 141.

  Next, as illustrated in FIG. 3, the terminal 144 and the second electrode 120 of the light emitting element 100 are connected by the first connection member 142. This step is performed, for example, by wire bonding.

  Next, as shown in FIG. 2, the sealing member 148 is bonded or welded to the mounting module 160 in a nitrogen atmosphere, for example. Thereby, the light emitting element 100 can be sealed.

  (7) The light emitting device 1000 of the present embodiment is obtained by the above steps as shown in FIGS.

  1.3. In the light emitting element 100 included in the light emitting device 1000 according to this embodiment, as described above, laser oscillation of light generated in the gain region 180 can be suppressed or prevented. Therefore, speckle noise can be reduced. Furthermore, in the light emitting device 1000 according to the present embodiment, light generated in the gain region 180 can travel while receiving gain in the gain region 180 and can be emitted to the outside. Therefore, it is possible to obtain a higher output than conventional general LEDs. As described above, according to the present embodiment, it is possible to provide a light-emitting device having a novel light-emitting element that can reduce speckle noise and has high output.

  Further, in the light emitting device 1000 according to the present embodiment, the two emitted lights L1 and L2 emitted from the light emitting element 100 in the horizontal direction can be both reflected toward the upper side of the light emitting element 100. Thereby, the structure of the optical system of the back | latter stage which is not shown in figure (optical system into which reflected light L3, L4 injects) can be simplified.

  Further, in the light emitting device 1000 according to the present embodiment, the two outgoing lights L1 and L2 can be both reflected in the same direction. That is, the traveling direction of the first reflected light L3 by the first reflecting surface 162 and the traveling direction of the second reflected light L4 by the second reflecting surface 164 can be made the same. As a result, the configuration of the subsequent optical system can be further simplified, and the optical axis alignment of the subsequent optical system can be facilitated.

  Further, in the light emitting device 1000 according to the present embodiment, the reflecting surfaces 162 and 164 are provided integrally with the mounting module 160. Thereby, the light emitting device 1000 can be reduced in size.

  In the light emitting device 1000 according to the present embodiment, the reflectance of the two reflecting surfaces 162 and 164 can be made higher than 50%. Thereby, the emitted lights L1 and L2 emitted from both ends of the light emitting element 100 can be efficiently used.

  In the light emitting device 1000 according to the present embodiment, the thermal conductivity of the first support member 140 and the second support member 141 can be made higher than the thermal conductivity of the light emitting element 100. Thereby, the 1st support member 140 and the 2nd support member 141 can function as a heat sink. Therefore, according to the present embodiment, it is possible to provide the light emitting device 1000 having excellent heat dissipation. Furthermore, in the light emitting device 1000 according to the present embodiment, the active layer 108 is provided on the mounting module 160 side of the light emitting element 100. Accordingly, it is possible to provide the light emitting device 1000 that is further excellent in heat dissipation.

  In the light emitting device 1000 according to this embodiment, the light emitting element 100 can be sealed using the sealing member 148. Thereby, the reliability of the light emitting device 1000 can be improved.

  1.4. Next, a modification of the light emitting device according to this embodiment will be described. In addition, a different point from the example of the light-emitting device 1000 shown in FIGS. 1-3 mentioned above is demonstrated, and description is abbreviate | omitted about the same point.

  (1) First, a first modification will be described.

  FIG. 9 is a plan view schematically showing a light emitting device 1100 according to this modification.

  In the example of the light emitting device 1000, as illustrated in FIG. 1, the case where each of the four side surfaces of the outer edge of the first support member 140 is not parallel to each of the four side surfaces of the outer edge of the light emitting element 100 has been described. . On the other hand, in this modification, as shown in FIG. 9, each of the four side surfaces of the outer edge of the first support member 140 is made parallel to each of the four side surfaces of the outer edge of the light emitting element 100. Can do. In the illustrated example, the number of the inclined side surfaces of the concave portion of the first support member 140 is six, and the surface of the reflecting portion 163 formed on two of the two sides is the first reflecting surface 162 and the second reflecting surface. Surface 164. Also in this modification, for example, the traveling direction of the first emitted light L1 is perpendicular to the intersection line V between the horizontal plane (XY plane) and the first reflecting surface 162, and the second emitted light L2 The advancing direction can be perpendicular to the intersection line W between the horizontal plane and the second reflecting surface 164.

  (2) Next, a second modification will be described.

  FIG. 10 is a plan view schematically showing a light emitting device 1200 according to this modification. FIG. 11 is a plan view schematically showing another light emitting device 1300 according to this modification, and FIG. 12 is a cross-sectional view taken along line XII-XII in FIG.

  In the example of the light emitting device 1000, the case where one gain region 180 is provided as shown in FIG. 1 has been described. On the other hand, in this modification, a plurality of gain regions 180 (for example, three in the illustrated example) can be provided. In the present modification, for example, as shown in FIG. 10, each of the first reflecting surfaces (surfaces that reflect the first outgoing light L1) with respect to the first end surfaces 170 of the three gain regions 180 has a single flat surface 166 as a whole. Can be configured. Similarly, in the present modification, for example, each of the second reflection surfaces (surfaces that reflect the second emitted light L2) with respect to the second end surface 172 of the three gain regions 180 forms one plane 168 as a whole. Can be. In the example shown in FIG. 10, each of the optical path lengths from the first end face 170 to the first reflecting surface (that is, the plane 166) of the three first outgoing lights L1 has a different value. For example, the optical path length from the first end face 170 to the plane 166 of the first outgoing light L1 emitted from the first end face 170 that is closer to the plane 166 is shorter among the three first end faces 170. In the illustrated example, the same applies to each of the optical path lengths from the second end face 172 to the second reflecting surface (that is, the plane 168) of the three second outgoing lights L2.

  Further, in the present modification, for example, as shown in FIGS. 11 and 12, each of the first reflecting surfaces 162 with respect to the first end surfaces 170 of the three gain regions 180 is separated from the first end surface 170 of the first emitted light L1. The optical path length to the 1st reflective surface 162 can be provided in the position used as the same. Similarly, in the present modification, for example, each of the second reflection surfaces 164 with respect to the second end surfaces 172 of the three gain regions 180 has an optical path length from the second end surface 172 to the second reflection surface 164 of the second emitted light L2. Can be provided at the same position. In the example shown in FIGS. 11 and 12, unlike the example shown in FIG. 10, each of the three first reflecting surfaces 162 does not constitute one plane but is a separate plane. In the illustrated example, the same applies to each of the three second reflecting surfaces 164.

  (3) Next, a third modification will be described.

  FIG. 13 is a cross-sectional view schematically showing a light emitting device 1400 according to this modification. Note that the cross-sectional view shown in FIG. 13 corresponds to the cross-sectional view shown in FIG.

In the example of the light emitting device 1000, the case where the first electrode 122 has the same planar shape as the gain region 180 from the top to the bottom has been described. On the other hand, for example, in the example shown in FIG. 13, the lower portion of the first electrode 122 can have a planar shape different from that of the gain region 180. In this modification, the insulating layer 202 having an opening can be formed under the contact layer 112, and the first electrode 122 filling the opening can be formed. The first electrode 122 is formed in the opening and under the insulating layer (including the opening) 202. In this modification, the upper portion of the first electrode 122 has the same planar shape as the gain region 180, and the lower portion of the first electrode 122 has the same planar shape as the insulating layer 202. As the insulating layer 202, for example, a SiN layer, a SiO ₂ layer, a polyimide layer, or the like can be used. The insulating layer 202 is formed by, for example, a CVD method or a coating method. For example, the first electrode 122 is directly joined to the second support member 141. This joining is performed by, for example, alloy joining or joining using a solder paste.

  According to this modification, since the volume under the first electrode 122 can be increased as compared with the example of the light emitting device 1000, the light emitting device 1400 having excellent heat dissipation can be provided.

  (4) Next, a fourth modification will be described.

  FIG. 14 is a cross-sectional view schematically showing a light emitting device 1500 according to this modification. FIG. 15 is a cross-sectional view schematically showing another light emitting device 1600 according to this modification. Note that each of the cross-sectional views shown in FIGS. 14 and 15 corresponds to the cross-sectional view shown in FIG.

  In the example of the light emitting device 1000, as shown in FIG. 2, the case where the first reflected light L3 and the second reflected light L4 travel vertically upward (Z direction in FIG. 1) with respect to the upper surface of the active layer 108 has been described. . On the other hand, in the present modification, at least one of the first reflected light L3 and the second reflected light L4 cannot advance vertically upward with respect to the upper surface of the active layer 108. For example, as shown in FIG. 14, the first reflected light L3 and the second reflected light L4 can travel in the direction inclined to the same side from the vertical direction (Z direction in FIG. 1). In the example shown in FIG. 14, the traveling direction of the first reflected light L3 is the same as the traveling direction of the second reflected light L4. Further, for example, as shown in FIG. 15, the first reflected light L3 can travel in a direction inclined from the vertical direction to one side, and the second reflected light L4 is inclined from the vertical direction to the other side. You can go in the direction. In the example shown in FIG. 15, the traveling direction of the first reflected light L3 and the traveling direction of the second reflected light L4 are directions of spreading, but although not shown, they may be narrowing directions. Note that also in the present modification, the first reflected light L3 and the second reflected light L4 can travel toward the upper side of the light emitting element 100. In the present modification, the inclination angles of the first reflecting surface 162 and the second reflecting surface 164 are adjusted as appropriate.

  (5) Next, a fifth modification will be described.

  In the example of the light emitting device 1000, the planar shape of the gain region 180 has been described as being linear as shown in FIG. 1, but in this modification, for example, the planar shape of the gain region 180 is not illustrated. It can be a curved line or a combination of a straight line and a curved line.

  (6) Next, a sixth modification will be described.

  In the example of the light-emitting device 1000, the case where the light-emitting element 100 is an InGaAlP-based semiconductor light-emitting element has been described. However, in this modification, any material system capable of forming a light-emitting gain region can be used. As the semiconductor material, for example, an AlGaN-based, InGaN-based, GaAs-based, InGaAs-based, GaInNAs-based, or ZnCdSe-based semiconductor material can be used. Moreover, in this modification, an organic material etc. can also be used, for example.

  (7) The modified example is not limited to the above-described example. For example, it is possible to appropriately combine the modified examples. Further, these modifications can be applied to the embodiments described later as needed.

2. Second Embodiment 2.1. Next, a light emitting device 2000 according to the second embodiment will be described.

  FIG. 16 is a cross-sectional view schematically showing the light emitting device 2000. The cross-sectional view shown in FIG. 16 corresponds to the cross-sectional view shown in FIG. 3 in the light emitting device 1000 according to the first embodiment. Further, in the light emitting device 2000 according to the second embodiment, members having the same functions as those of the constituent members of the light emitting device 1000 according to the first embodiment described above are denoted by the same reference numerals, and detailed descriptions thereof are given. Omitted.

  The light emitting device 2000 includes a mounting module 160 and a light emitting element 600. The light emitting device 2000 can further include, for example, an insulating member 146, a terminal 144, a first connection member 142, and a sealing member 148.

  As shown in FIG. 16, the light emitting device 600 includes a first cladding layer 110, an active layer 108, a second cladding layer 106, and an insulating part 602. The light emitting device 600 can further include, for example, a first electrode 122, a second electrode 120, a substrate 102, a buffer layer 104, and a contact layer 112.

  The entire active layer 108 constitutes a gain region 180. For example, the second cladding layer 106, the active layer 108, the first cladding layer 110, and the contact layer 112 have the same planar shape as the gain region 180. For example, at least a portion of the contact layer 112 on the side of the contact surface with the first electrode 122 (lower portion of the contact layer 112) can constitute a columnar semiconductor deposited body (hereinafter referred to as “columnar portion”) 610. For example, as shown in FIG. 16, the second cladding layer 106, the active layer 108, the first cladding layer 110, and the contact layer 112 can constitute a columnar portion 610.

  As shown in FIG. 16, the insulating portion 602 is provided on the side of the columnar portion 610. The insulating portion 602 is formed, for example, under a layer (buffer layer 104 in the illustrated example) that is in contact with the opposite side of the columnar portion 610 to the first electrode 122 side. The insulating unit 602 is formed between the first electrode 122 and the buffer layer 104. For example, the insulating unit 602 can cover at least the side surface of the active layer 108 between the first side surface 107 and the second side surface 109 of the active layer 108. For example, of the side surfaces of the columnar portion 610, the side surfaces other than the first side surface 107 side and the second side surface 109 side are covered with the insulating portion 602. As shown in FIG. 16, the insulating portion 602 is in contact with the side surface of the columnar portion 610. The current between the electrodes 120 and 122 can flow through the columnar portion 610 sandwiched between the insulating portions 602, avoiding the insulating portions 602. For example, the current path between the electrodes 120 and 122 is determined by the planar shape of the columnar portion 610, and as a result, the planar shape of the gain region 180 is determined. Although not shown, the columnar portion 610 and the insulating portion 602 can also be formed on the substrate 102 side.

The insulating unit 602 can have a refractive index lower than that of the active layer 108, for example. For example, when the side surface of the active layer 108 is covered with the insulating portion 602, light can be efficiently confined in the active layer 108. In the light emitting device 600 according to the present embodiment, light generated in the gain region 180 is coupled to a propagation mode that is formed by the refractive index difference and propagates in the axial direction of the gain region 180 (the above-described “certain direction”). Therefore, there is almost no light that propagates in a direction different from the axial direction of the gain region 180. For example, when the first end surface 170 and the second end surface 172 facing each other in the gain region 180 overlap in a plan view from the first side surface 107 side, the first end surface 170 and the second end surface 172 are overlapped at the overlapping portion. Is different from the axial direction of the gain region 180. For this reason, there is almost no light propagating in the direction connecting the first end face 170 and the second end face 172 vertically. Therefore, the light emitting element 600 that emits light that is not laser light can be obtained by providing the gain region 180 in a direction inclined with respect to the normal line P of the first side surface 107 and suppressing or preventing multiple reflection of light. it can. As the insulating portion 602, for example, a SiN layer, a SiO ₂ layer, a polyimide layer, or the like can be used.

  For example, as shown in FIG. 16, the first electrode 122 is formed on the entire surface under the columnar portion 610 and the insulating portion 602. Thereby, since the volume of the 1st electrode 122 increases compared with the example of the light-emitting device 1000 shown in FIGS. 1-3 mentioned above, the light-emitting device 2000 excellent in heat dissipation can be provided.

  2.2. Next, an example of a method for manufacturing the light emitting device 2000 according to the second embodiment will be described with reference to the drawings, but is not limited to the following example. Note that differences from the method of manufacturing the light emitting device 1000 according to the first embodiment described above will be described, and detailed description of similar points will be omitted.

  17 and 18 are cross-sectional views schematically showing the manufacturing process of the light-emitting device 2000, and correspond to the cross-sectional view shown in FIG.

  (1) First, the buffer layer 104, the second cladding layer 106, the active layer 108, the first cladding layer 110, and the contact layer 112 are formed on the substrate 102.

  (2) Next, as shown in FIG. 17, the second cladding layer 106, the active layer 108, the first cladding layer 110, and the contact layer 112 are patterned. The patterning is performed using, for example, a photolithography technique and an etching technique. By this step, the columnar portion 610 can be formed.

  (3) Next, as shown in FIG. 18, an insulating portion 602 is formed so as to cover the side surface of the columnar portion 610. Specifically, first, an insulating layer (not shown) is formed on the entire surface of the buffer layer 104 (including on the contact layer 112) by, for example, a CVD method or a coating method. Next, the upper surface of the contact layer 112 is exposed using, for example, an etching technique. Through the above steps, the insulating portion 602 can be obtained.

  Next, as shown in FIG. 18, the first electrode 122 and the second electrode 120 are formed. Since the first electrode 122 may be formed over the entire surface of a flat surface, the risk of disconnection of the first electrode 122 can be reduced. Moreover, since the patterning process of the 1st electrode 122 is unnecessary, a manufacturing process can be simplified.

  (4) Through the above steps, the light emitting device 600 of this embodiment is obtained as shown in FIG. In the present embodiment, the second connection member 143 (see FIG. 3) may not be formed on the first electrode 122 of the light emitting element 600.

  (5) The subsequent steps are the same as the steps in the method for manufacturing the light emitting device 1000 according to the first embodiment described above.

  (6) The light emitting device 2000 of the present embodiment is obtained through the above steps.

  2.3. According to the present embodiment, as in the first embodiment described above, it is possible to provide a light emitting device having a novel light emitting element that can reduce speckle noise and has high output.

  2.4. Next, a modification of the light emitting device according to this embodiment will be described. Note that differences from the example of the light-emitting device 2000 illustrated in FIG. 16 described above will be described, and description of similar points will be omitted.

  (1) First, a first modification will be described.

  FIG. 19 is a cross-sectional view schematically showing a manufacturing process of the light emitting device according to this modification. Note that the cross-sectional view shown in FIG. 19 corresponds to the cross-sectional view shown in FIG.

  In the example of the light emitting device 2000, after forming the columnar portion 610 as shown in FIG. 17, an insulating layer (not shown) is formed, and then the contact layer 112 is exposed to form the insulating portion 602. Explained the case. On the other hand, in this modified example, first, as shown in FIG. 19, for example, the region above the gain region 180 on the contact layer 112 is covered with a mask layer 704 such as a photoresist. Next, ions 706 such as protons are implanted to a depth reaching the upper surface of the buffer layer 104, for example, using the mask layer 704 as a mask. Through the above steps, the insulating portion 602 according to the present modification can be formed.

  (2) Next, a second modification will be described.

  FIG. 20 is a cross-sectional view schematically showing a light emitting device 2100 according to this modification.

  In the example of the light emitting device 2000, as shown in FIG. 16, the case where the insulating portion 602 is a thick film has been described. On the other hand, in this modification, as shown in FIG. 20, the insulating part 602 can be a thin film. In this modification, the thickness (the length in the vertical direction) of the insulating portion 602 is the same as the thickness of the columnar portion 610 in the portion covering the columnar portion 610, but the thickness of the columnar portion 610 in the other portions. It is smaller than this.

  In the illustrated example, the first electrode 122 has the same planar shape as that of the gain region 180, as in the example of the light-emitting device 1000 illustrated in FIGS. 1 to 3 described above, and the second support member 143 provides the second support member. 141.

  (3) The modification is not limited to the above-described example. For example, it is possible to appropriately combine the modified examples. Moreover, these modifications and the example of the light-emitting device 2000 are applicable also to embodiment mentioned above as needed.

  3. Although the embodiments of the present invention have been described in detail as described above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

1 is a plan view schematically showing a light emitting device according to a first embodiment. 1 is a cross-sectional view schematically showing a light emitting device according to a first embodiment. 1 is a cross-sectional view schematically showing a light emitting device according to a first embodiment. The figure which looked at the active layer of 1st Embodiment planarly from the 1st side surface side. Sectional drawing which shows schematically the manufacturing process of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the manufacturing process of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the manufacturing process of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the manufacturing process of the light-emitting device of 1st Embodiment. The top view which shows roughly the 1st modification of the light-emitting device of 1st Embodiment. The top view which shows roughly the 2nd modification of the light-emitting device of 1st Embodiment. The top view which shows roughly the 2nd modification of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the 2nd modification of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the 3rd modification of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the 4th modification of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the 4th modification of the light-emitting device of 1st Embodiment. Sectional drawing which shows schematically the light-emitting device of 2nd Embodiment. Sectional drawing which shows schematically the manufacturing process of the light-emitting device of 2nd Embodiment. Sectional drawing which shows schematically the manufacturing process of the light-emitting device of 2nd Embodiment. Sectional drawing which shows schematically the manufacturing process of the 1st modification of the light-emitting device of 2nd Embodiment. Sectional drawing which shows schematically the 2nd modification of the light-emitting device of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Light emitting element, 102 board | substrate, 104 buffer layer, 106 2nd clad layer, 107 1st side surface, 108 active layer, 109 2nd side surface, 110 1st clad layer, 112 contact layer, 120 2nd electrode, 122 1st electrode 140, first support member, 141 second support member, 142 first connection member, 143 second connection member, 144 terminal, 145 recess, 146 insulating member, 147 through hole, 148 sealing member, 160 mounting module, 162 first 1 reflective surface, 163 reflective portion, 164 second reflective surface, 166, 168 plane, 170 first end surface, 172 second end surface, 180 gain region, 202 insulating layer, 600 light emitting element, 602 insulating portion, 610 columnar portion, 704 Mask layer, 706 ions, 1000, 1100, 1200, 1300, 1400, 15 0,1600,2000,2100 light-emitting device

Claims (12)

A light emitting element;
A mounting substrate on which the light emitting element is mounted;
Including
The light emitting element is
An active layer,
Two cladding layers sandwiching the active layer;
Have
At least a portion of the active layer constitutes a gain region where current is injected to generate and amplify light;
The gain region extends from the first side surface of the active layer to the second side surface of the active layer facing the first side surface in a plan view from the stacking direction of the active layer and the cladding layer. Provided extending in a direction inclined with respect to the vertical of the side surface,
The mounting substrate is
A first reflecting surface for reflecting the first emitted light emitted from the first end surface on the first side surface side of the gain region in a direction away from the surface on which the light emitting element of the mounting substrate is mounted;
A second reflecting surface for reflecting the second emitted light emitted from the second end surface on the second side surface of the gain region in a direction away from the surface on which the light emitting element of the mounting substrate is mounted;
I have a,
A plurality of the gain regions are provided,
Each of the first reflecting surfaces with respect to the first end surface of the plurality of gain regions is provided at a position where the optical path lengths from the first end surface of the first emitted light to the first reflecting surface are the same,
Each of the second reflecting surfaces with respect to the second end surface of the plurality of gain regions is provided at a position where the optical path lengths from the second end surface to the second reflecting surface of the second emitted light are the same.
Each of the first reflective surfaces is a separate plane;
Each of the second reflective surfaces is a separate plane;
The direction in which the light reflected by the first reflecting surface travels is the same as the direction in which the light reflected by the second reflecting surface travels . In claim 1 ,
The direction in which the light reflected by the first reflective surface travels and the direction in which the light reflected by the second reflective surface travels are vertically upward with respect to the upper surface of the active layer. In claim 1 or 2 ,
The traveling direction of the first emitted light is perpendicular to the line of intersection between the surface parallel to the upper surface of the active layer and the first reflecting surface in a plan view from the stacking direction,
The light emitting device, wherein the traveling direction of the second emitted light is perpendicular to a line of intersection between a surface parallel to the upper surface of the active layer and the second reflecting surface in a plan view from the stacking direction. In any one of Claims 1 thru | or 3 ,
In the gain region, the first end surface and the second end surface do not overlap with each other in plan view from the first side surface side. In any one of Claims 1 thru | or 4 ,
The light emitting element is
A light emitting device having an electrode electrically connected to the two cladding layers. In any one of Claims 1 thru | or 5 ,
The reflectance of each of the first reflection surface and the second reflection surface is higher than 50% and 100% or less. In any one of Claims 1 thru | or 6 .
The mounting substrate has a support member that supports the light emitting element,
The light-emitting device wherein the support member has a thermal conductivity higher than that of the light-emitting element. In any one of Claims 1 thru | or 7 ,
The light emitting device further includes a support substrate that directly or indirectly supports the active layer,
The light emitting device, wherein the active layer is provided on the mounting substrate side with respect to the support substrate. In any one of Claims 1 thru | or 8 .
Including a sealing member for sealing the light emitting element,
The light emitting device, wherein the light reflected by the first reflecting surface and the light reflected by the second reflecting surface are transmitted through the sealing member.   A semiconductor light emitting device including a first end face from which light is emitted, and a plurality of optical waveguides extending obliquely with respect to a normal direction of the first end face;
  A mounting substrate having a recess in which the semiconductor light emitting element is disposed,
  The first end surface includes a plurality of first light emitting portions corresponding to the end portions of the plurality of optical waveguides,
  The inner side wall of the recess includes a first reflecting surface that reflects light emitted from the first end surface,
  The surface of the first reflecting surface is such that the optical path lengths between the first light emitting portion and the first reflecting surface of the light emitted from each of the plurality of first light emitting portions are equal to each other. A light emitting device formed in a step shape.   In claim 10,
  The semiconductor light emitting device further includes a second end surface that is a surface opposite to the first end surface,
  The second end surface includes a plurality of second light emitting portions corresponding to the ends of the plurality of optical waveguides,
  The inner side wall of the recess includes a second reflecting surface that reflects light emitted from the second end surface,
  The surface of the second reflecting surface is such that the optical path lengths between the second light emitting portion and the second reflecting surface of the light emitted from each of the plurality of second light emitting portions are equal to each other. A light emitting device formed in a step shape.   In claim 11,
  The light emitted from each of the plurality of first light emitting units is emitted from each of the plurality of second light emitting units and the optical path length between the first light emitting unit and the first reflecting surface. The light emitting device, wherein an optical path length between the second light emitting portion of light and the second reflecting surface is equal.

Images