JPH11261111A - Light-emitting device equipped with monitoring mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device which is equipped with a monitoring mechanism, where the device can be used on visible light and lessened in size. SOLUTION: A surface-emitting type semiconductor light-emitting device 20 is provided on a semiconductor photodetecting device 30 equipped with a transparent electrode 31 on its surface, and the upper part of the light-emitting device 20 is housed in a recess 12 of a light guide/reflecting board 10. A recess 13 and a light extracting hole 18 are provided to the light guide/reflectiong board 10 which communicates with the recess 12, and a metal film 14 is formed on their inner walls. Most of the light (visible light) emitted from the semiconductor light-emitting device 20 is emitted to the outside through the light extracting hole 18. A part of the light emitted from the light-emitting device 20 is reflected from the metal film 14 formed on the inner wall of the recess 13 and is incident on the semiconductor photodetecting device 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device having a monitor function for detecting a part of light emitted from a light emitting element and performing feedback control of the light emitted from the light emitting element.

[0002]

2. Description of the Related Art FIG. 14 is a schematic view of a conventional light emitting device having a monitor mechanism.

A light emitting device 70 having a monitor mechanism includes a light emitting element 71 provided on a substrate 74, and a light receiving element 72 provided at a position facing the light emitting surface side (upward in FIG. 14) of the light emitting element 71. , A half mirror 73 provided between the light emitting element 71 and the light receiving element 72.

Light emitted from the light emitting element 71 enters a half mirror 73. The half mirror 73 is arranged so that its light incident surface has an angle of 45 degrees with respect to the traveling direction of the light emitted from the light emitting element 71. Part of the light incident on the half mirror 73 is reflected by the half mirror 73,
The light is output outside as light emitted from the light emitting element 71. Light emitting element
Another part of the light emitted from the light 71 passes through the half mirror 73 and enters the light receiving surface of the light receiving element 72.

The light transmitted through the half mirror 73 is a light receiving element
The light is received by the light source 72, whereby the light intensity, light output, and the like of the light emitted from the light emitting element 71 are detected. However, there is a problem that the light incident on the light receiving element 72 passes through the half mirror 73, causing light loss and increasing the size of the entire apparatus.

FIG. 15 is a schematic view showing another example of a light emitting device having a conventional monitor mechanism.

On a substrate 86, a light emitting element 81 and a light receiving element 82
Are arranged side by side. The entire surface of the substrate on which the light emitting element 81 and the light receiving element 82 are provided is covered by an elliptical cover 83. A light extraction hole 84 is formed in a portion of the cover 83 above the light emitting element 81. Part of the light emitted from the light emitting element 81 is emitted outside through the light extraction hole 84.

On the inner surface of the cover 83, a reflection film 85 is provided. Another part of the light emitted from the light emitting element 81 is reflected by the reflection film 85 and enters the light receiving surface of the light receiving element. The intensity, output and the like of the light emitted from the light emitting element 81 are detected.

Light emitting device 80 having a monitor mechanism shown in FIG.
Then, it is necessary to provide the light emitting element 81 and the light receiving element 82 side by side on the same surface on the substrate 86. In order to make the light emitted from the light emitting element 81 incident on the light receiving surface of the light receiving element 82, the cover 83 has a predetermined curvature, and the inner surface of the cover 83 and the light emitting element
It is necessary to ensure a certain distance between the light emitting surface of 81 and the light receiving surface of light receiving element 82. For this reason, it is difficult to reduce the size of the entire device.

FIG. 16 shows a conventional light emitting device provided with another monitor mechanism. In this light emitting device,
The light emitting device 90 includes a lower electrode 91, a substrate 92, a lower cladding layer 93,
It comprises an active layer 94, an upper cladding layer 95, and a top electrode 96 with a light exit hole 97. Light receiving element 100
Denotes a lower electrode 101, an n-type semiconductor layer 103, a p-type semiconductor layer 104
And an upper electrode 102. The lower electrode 91 of the light emitting element 90 and the upper electrode 102 of the light receiving element 100 are common. For the lower electrode 91 (upper electrode 103), a metal material (transparent electrode) that transmits light is used. As described above, in the structure in which the light receiving element 100 is formed on the rear surface side (the surface opposite to the light emitting surface) of the front emission type semiconductor light emitting element 90, of the light generated in the active layer 94 of the light emitting element 90,
By detecting the light going to the back of the light emitting element 90,
The intensity of light emitted from the light emitting element 90 is detected.

However, semiconductor materials (such as n-GaAs and n-InP) generally used for the substrate 92 of the light emitting element 90 have a property of absorbing visible light. In a structure in which light from the active layer 94 is received through the substrate 92, visible light incident on the light receiving element 100 is weak or nonexistent, and it is difficult or impossible to detect the light intensity, light output, and the like of visible light.

[0012]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a small-sized light emitting device having a monitor mechanism having a structure usable for a light emitting element of visible light.

A light emitting device having a monitor mechanism according to the present invention is a surface emitting type light emitting element in which an upper surface electrode is formed on an upper surface and a lower electrode is formed on a lower surface, and at least a part of the upper surface is a light emitting surface. A concave portion for accommodating at least the upper part of the emission type light emitting element and a light extraction hole connected to the concave portion are formed, and a part of the light emitted from the light emission surface is guided to the outside through the light extraction hole, and other light is emitted. A light guide / reflection substrate having a light guide / reflection surface formed so that a part thereof is directed downward through a side of the surface emission type light emitting element; and a lower surface of the surface emission type light emitting element is joined to a part of an upper surface. A light receiving element for receiving light traveling downward by the light guide reflection surface of the light guide reflection substrate is provided.

A surface emitting type light emitting element is generally an LED.
It is. The LED emits minute and high-brightness light. The surface emitting light emitting element may be a semiconductor laser.

According to the present invention, most of the light emitted from the light emitting surface of the light emitting element is emitted to the outside through the concave portion and the light extraction hole, and the other part is reflected by the light guide reflecting surface to receive light. Light enters the element. For this reason, even if the light emitted from the light emitting element is visible light, the light emitted from the light emitting element can be monitored. Since a part of the light emitted from the light emitting element is incident on the light receiving element with almost no loss, it is possible to monitor the faint emitted light. Furthermore, since a part of the surface emitting light emitting element bonded on the light receiving element is housed in the light guide reflection substrate, the size of the light emitting device can be reduced.

In one embodiment, the concave portion of the light guide / reflective substrate connects a first concave portion for accommodating at least an upper portion of the surface emitting type light emitting element, the first concave portion and the light extraction hole, and emits light from the surface. A second concave portion for guiding the light emitted from the mold light emitting element to the light extraction hole; a step is formed at a boundary between the first concave portion and the second concave portion; At least a part of the upper surface electrode of the surface emitting light emitting element is in contact with the step portion. The light guide reflection surface is formed on the inner surface of the second recess.

Preferably, a conductive material is used as the material of the substrate. Since the upper surface electrode of the surface-emitting type light emitting element accommodated in the recess is in contact with the substrate at the step, the upper surface electrode can be connected to a driving circuit, a control circuit, or the like provided outside through the substrate.

In another embodiment, the space between the front emission type light emitting element and the recess is filled with a transparent resin. The front emission type light emitting element is stably fixed in the concave portion. Part of the light emitted from the surface-emitting type light emitting element enters the light receiving element through the transparent resin.

By arranging a plurality of sets of light-emitting elements, light-guiding reflective substrates and light-receiving elements two-dimensionally on one substrate, the output light output can be controlled for each light-emitting element and the light emission of the array structure can be controlled. Since it is a device, a large amount of emitted light can be obtained.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show longitudinal sections of a light emitting device provided with a monitor mechanism, each having a cut surface which is different by 90 °. FIG. 1 shows an electric circuit (drive control circuit) of the light emitting device. ) Is also shown. FIG. 3 is a perspective view showing the structure (outer shape of the concave portion) of the concave portion formed in the light guide reflecting substrate 10 shown in FIGS. 1 corresponds to a section taken along line II in FIG. 3, and FIG. 2 corresponds to a section taken along line II-II in FIG.

The light emitting device provided with the monitor mechanism includes a surface emitting type semiconductor light emitting element 20 (hereinafter, referred to as a light emitting element 20), a light guide reflecting substrate 10, and a semiconductor light receiving element 30.

The light emitting element 20 has a rectangular parallelepiped outer shape. That is, the side surface of the light emitting element 20 includes a surface having one long side in the horizontal direction (long side in the longitudinal direction) and a surface having one short side (side in the short side direction). The cross section of the light emitting device 20 shown in FIG. 1 is obtained by cutting the light emitting device 20 in parallel with the longitudinal direction.
The cross section of 20 is a cross section obtained by cutting the light emitting element 20 in parallel with the lateral direction.

The light emitting element 20 is composed of a semiconductor layer 21, an upper electrode 25 formed on the upper surface of the semiconductor layer 21, and a lower electrode 26 formed on the lower surface of the semiconductor layer 21. The semiconductor layer 21 is formed by an LPE method (Liquid Phase Epitaxy).
Is formed by sequentially laminating a lower cladding layer, an active layer, and an upper cladding layer on a semiconductor substrate. 1 and 2, the detailed illustration of the semiconductor layer 21 is omitted.

The upper electrode 25 is formed in a region other than the central circular region on the upper surface of the semiconductor layer 21. The central circular region on the upper surface of the semiconductor layer 21 where the upper electrode 25 is not formed is
The light exit window 27. On the other hand, the lower electrode 26 is formed on the entire lower surface of the semiconductor layer 21. Top electrode 25 and semiconductor layer 2
1. The lower electrode 26 and the semiconductor layer 21 are preferably alloyed by annealing and are in ohmic contact. Top electrode
When a current flows between the lower electrode 25 and the lower electrode 26, visible light is generated from the semiconductor layer 21 (active layer), and this light is emitted from the light emission window 27 to the outside.

Below the light emitting element 20, a semiconductor light receiving element 30
(Hereinafter, referred to as a light receiving element 30).

As the light receiving element 30, a pn junction type in which a p-type (or n-type) semiconductor layer (upper layer) 33 is laminated on an n-type (or p-type) semiconductor layer (lower layer) 34 is shown. I have. The light receiving element 30 includes a pn junction type, a pin junction type,
Other semiconductor structures such as a Schottky type and an avalanche type can also be used.

An upper electrode 31 is formed on the entire upper surface of the p-type semiconductor layer 33 of the light receiving element 30, and a lower electrode 32 is formed on the entire lower surface of the n-type semiconductor layer 34. As a material of the upper surface electrode 31, a transparent conductive material represented by ITO (indium tin oxide) is used. ITO has a light transmittance of 90
% Or more and a material having good electrical conductivity. For the lower electrode 32, a metal material such as Au (gold) is used.

The surface (upper surface) on which the upper electrode (transparent electrode) 31 is formed is the light receiving surface of the light receiving element 30. When light enters the light receiving surface of the light receiving element 30, the light receiving element 30 outputs a light receiving signal (electric signal). This light receiving signal is extracted from the upper electrode 31 and the lower electrode 32 and input to the drive control circuit 28.

The upper surface (and lower surface) of the light receiving element 30 is wider than the lower surface (and upper surface) of the light emitting element 20. The lower electrode 26 of the light emitting element 20 is fixed to the center of the upper electrode 31 of the light receiving element 30 by anodic bonding. As will be described later, the light receiving element 30 receives a part of the visible light emitted from the light emitting element 20 on its light receiving surface (excluding the part where the light emitting element 20 is joined).

The light guide reflection substrate 10 includes the silicon substrate 9.
The silicon substrate 9 can be finely processed by performing high-precision etching.

The light guide reflecting substrate 10 has two recesses 12 and
13 are formed. The concave portion 12 is opened in a rectangular shape on the lower surface of the silicon substrate 9. Most inner walls of the concave portion 12 are inclined in a direction to become narrower. The concave portion 13 has a substantially quadrangular pyramid shape which continues to the upper portion of the concave portion 12 and becomes narrower upward. Recess
Reference numeral 13 denotes an opening above the silicon substrate 9 via the light extraction hole 18. At the boundary between the concave portions 12 and 13, there are step portions parallel to the upper and lower surfaces of the silicon substrate 9.

Inner walls of recesses 12 and 13 and light extraction hole
The metal film 14 is formed on the inner periphery of 18. For the metal film 14, a metal material having good conductivity and high light reflectance (for example, Au (gold), Al (aluminum), etc.) is used.

An SiO 2 layer 15 and a nitride film 16 are laminated on substantially the entire upper and lower surfaces of the light guide reflection substrate 10. An electrode 17 is formed on the SiO2 layer 15 and the nitride film 16 on the upper half (the right half in FIG. 1). Electrode 17
It is electrically connected to the upper surface of the light guide / reflective substrate 10 through holes (pin holes) 17a formed in the SiO2 layer 15 and the nitride film 16 (there is also an electrode member in these holes).

In the light guide reflecting substrate 10 having the above-described structure, the upper portion of the light emitting element 20 is accommodated in the concave portion 12 and the light emitting element 20 is formed.
Is arranged so as to cover the upper part. The upper surface electrode 25 of the light emitting element 20 has solder and conductive resin (not shown in the drawing) on the metal film 14 at both ends including the short side of the light guide reflection board 10 at the step portion corresponding to the boundary between the concave portions 12 and 13. ). The upper electrode 25 of the light emitting element 20 is electrically connected to the electrode 17 through the metal film 14 and the light guide reflection substrate 10 made of silicon. When a current is caused to flow between the electrode 17 and the lower electrode 26 of the light emitting element 20 by the drive control circuit 28, the light emitting element 20 emits light from the light emission window 27.

The portion including the upper longitudinal side of the light emitting element 20 does not contact the step, and there is a gap between the longitudinal side of the light emitting element 20 and the inner surface of the recess 12.

Most of the light emitted from the light emission window 27 is directly emitted to the outside through the light extraction hole 18 formed on the upper surface of the light guide reflection substrate 10. Part of the light emitted from the light emission window 27 is reflected by the metal film 14 formed on the inner wall of the recess 13. Recess 13
Is formed in a substantially quadrangular pyramid with the light extraction hole 18 as a center, so that most of the light reflected by the metal film 14
, High intensity light is emitted from the light extraction hole 18. Further, part of the light reflected by the metal film 14 is
Then, the light enters the light receiving surface of the light receiving element 30 through a gap between the side surface in the longitudinal direction and the inner surface of the concave portion 12 (see FIG. 3). Light receiving element 30
Outputs a light receiving signal corresponding to the intensity of the incident light. The light receiving signal from the light receiving element 30 is given to the drive control circuit 28.

The drive control circuit 28 drives the light emitting element 20 based on the signal obtained from the light receiving element 30 so that the intensity of the light emitted from the light emitting element 20 is always constant. This gives
The light emitting output of the light emitting element 20 is stabilized.

The inner wall of the concave portion 12 of the light guide reflecting substrate 10 and the light emitting element
A transparent resin 29 is filled in the gap between the outside and the inside of the recess 20, the inside of the concave portion 13, and the inside of the light extraction hole 18. Thereby, the light emitting element 20 is securely fixed in the recess 12.

4 and 5, the steps of manufacturing the light guide reflecting substrate 10 shown in FIGS. 1 to 3 and the steps of mounting the light emitting elements 20 on the light guide reflecting substrate 10 will be described.

A silicon substrate 9 is prepared. This silicon substrate 9 is doped with impurities such as P (phosphorus) and B (boron) (FIG. 4A). The conductivity of the silicon substrate 9 is improved by doping with impurities.

Thermal oxidation or CDV (Chemical Vapor Depositio) is applied to the entire upper and lower surfaces of the silicon substrate 9.
n: a chemical vapor deposition method) to form an SiO2 layer 15 (FIG. 4B). Subsequently, on the SiO2 layer 15 formed on the upper and lower surfaces of the silicon substrate 9, a nitride film 16 (for example, Si
₃ N ₄₎ and formed by a CVD method (FIG. 4 (C)). SiO
The two layers 15 and the nitride film 16 are used as an etching mask in an etching step as described later. SiO
By laminating the two layers 15 and the nitride film 16 in two layers, the warpage of the silicon substrate 9 is prevented.

A resist is applied on the entire surface of the nitride film 16 on the upper surface of the silicon substrate 9. The resist at the portion that is to become the light extraction hole 18 is removed by photolithography. The area where the resist was removed (light extraction hole
The SiO2 layer 15 and the nitride film 16 (the part to be 18) are removed by etching. Remove all resist. On the upper surface of the silicon substrate 9, the SiO2 layer 15 and the nitride film 16 remain in a region other than a portion to become the light extraction hole 18. Dry etching is performed using the remaining SiO2 layer 15 and nitride film 16 as an etching mask. A portion to be the light extraction hole 18 is formed (FIG. 4D).

A resist is applied over the entire surface of the nitride film 16 on the lower surface of the silicon substrate 9. By the photolithography technique, the resist in the portion that is to be the lower surface opening of the concave portion 12 is removed. Subsequently, the SiO2 film 15 and the nitride film 16 laminated on the portion where the resist has been removed are removed by etching. Remove all resist. On the lower surface of the silicon substrate 9, the SiO2 film 15 and the nitride film 16 remain in a region excluding the portion that is to be the lower surface opening of the concave portion 12. Dry etching is performed using the remaining SiO2 film 15 and nitride film 16 as an etching mask. A lower portion of the concave portion 12 (this is indicated by reference numeral 12a) is formed (FIG. 4E).

From the lower surface of the silicon substrate 9, wet etching is performed using the SiO 2 layer 15 and the nitride film 16 laminated on the lower surface of the silicon substrate 9 as a mask. In the silicon substrate 9, the upper portion of the concave portion 12a is scraped off like a cone.
An upper portion of the concave portion 12 (this is indicated by reference numeral 12b) is formed (FIG. 4F).

A nitride film 19 is formed on the outer peripheral portion of the upper bottom of the concave portion 12 (the portion to be a step). When the wet etching is performed from the concave portion 12, the silicon substrate 9 is scraped off above the concave portion 12 like a cone to form the concave portion 13 (FIG. 5 (G)).
). The recess 13 and the light extraction hole 18 communicate with each other. At the boundary between the concave portion 12 and the concave portion 13, a step portion is formed at a portion where the nitride film 19 is provided. The nitride film 19 used for the mask is removed.

The inner walls of the recesses 12 and 13 (including the step),
In addition, the metal film 14 is formed on the inner periphery of the light extraction hole 18 by vapor deposition or sputtering (FIG. 5 (H)).

SiO 2 laminated on a silicon substrate 9
A part of the layer 15 and the nitride film 16 (designated by reference numeral 17a) is removed,
Half area of the upper surface of silicon substrate 9 (right half in the drawing)
The electrode 17 is formed by vapor deposition or sputtering (see FIG. 5).
(I)). The electrode 17 and the silicon substrate 9 come into contact with each other, and these are electrically connected. The light guide reflection substrate 10 is completed.

The light emitting element 20 is accommodated in the concave portion 12 of the light guide reflecting substrate 10, and both ends of the upper surface electrode 25 of the light emitting element 20 in the short direction and the metal film 14 at the step portion are soldered or conductive resin. Then, the electrical connection state is maintained and fixed (FIG. 5 (J)).

The gap between the inner wall of the recess 12 and the outside of the light emitting element 20, the inside of the recess 13 and the inside of the light extraction hole 18
29 is filled (FIG. 5 (K)). Finally, the light guide reflection substrate 10 in which the upper part of the light emitting element 20 is accommodated is mounted on the light receiving element 30 by anodic bonding (FIGS. 1 to 3).

Preferably, a plurality of recesses 12 and 13 are regularly and two-dimensionally formed in a silicon wafer, and the light emitting element 20 is placed in each of the plurality of recesses 12 formed.
This silicon wafer is divided by dicing.
Since the light-guiding reflective substrate 10 in which the upper part of the light emitting element 20 is housed is produced in large quantities at one time, the productivity is improved.

The light emitting element 20 may be mounted on the light receiving element 30 in advance, and the light guide reflecting substrate 20 may be covered on the light emitting element 20.

In the above-described light emitting device, the light (visible light) emitted from the light emitting element 20 housed in the light guide reflecting substrate 10 is received by the light receiving element 30.
In order to make the light incident on the light-emitting element 20, a rectangular shape is used for the light-emitting element 20, and the light-emitting element 20 has a rectangular parallelepiped. Form a gap to receive light (visible light) from light emitting element 20
It is incident on 30 light receiving surfaces. In order to allow a part of the light of the light emitting element 20 to enter the light receiving element 30, various shapes can be adopted as the shape of the concave portion 12 and the shape of the light emitting element 20. For example, when the cubic light emitting element 20 is used, the lengths of two orthogonal sides forming the concave portion 20 formed in the light guide reflecting substrate 10 may be different. An optical path for the light reflected by the metal film 14 to travel to the light receiving element 30 is secured.

The height (depth) of the concave portion 13 formed above the light emitting element 20 and the portion of the light emitting element 20 from which light is emitted (2
It has been clarified by simulation that in one embodiment, the size of the light exit window 27) is related to the directivity angle of the exit light. When the light emitting element has a circular light exit window on the upper surface, the diameter of the light exit window 27 of the light emitting element 20 and the distance from the upper surface of the light emitting element 20 to the entrance of the light extraction hole 18 (the recess 13) Are equal, the smallest directional angle is obtained. In the case of a light-emitting element having a square upper surface and emitting light from almost the entire surface, the smallest length is obtained when the length of one side of the upper surface of the light-emitting element is equal to the distance from the upper surface of the light-emitting element to the entrance of the light extraction hole 18. A directional angle is obtained. The directivity angle at this time is 30 ° or less.

As the light emitting element 20, not only a light emitting diode but also a semiconductor laser can be used. A stable laser output can be obtained.

FIGS. 6 and 7 are perspective views showing other examples of the surface-emitting type semiconductor light emitting device. In the surface-emitting type semiconductor light emitting device shown in FIGS. 6 and 7, an upper surface electrode formed on the upper surface of the semiconductor layer is different from the surface emitting type semiconductor light emitting device 20 shown in FIGS.

In FIG. 6, A is formed around the upper surface of the semiconductor layer.
A metal material such as u (gold) is formed.
25a), and the upper electrode 25a is in ohmic contact with the semiconductor layer. Further, a transparent electrode 25b using a transparent conductive material such as ITO (indium tin oxide) is formed in a region on the upper surface of the semiconductor layer surrounded by the upper electrode 25a. The current efficiently flows through the entire light emitting element, and the light extraction efficiency is improved.

In FIG. 7, the upper electrode 25c is made of Au (gold).
The upper surface electrode 25c and the upper surface of the semiconductor layer are in ohmic contact with each other except that the outer periphery of the upper surface of the light emitting element is formed using a metal material such as this. A transparent electrode 25d is formed in a region surrounded by the upper electrode 25c. Since current efficiently flows through the entire light emitting element, the light extraction efficiency of the light emitting element can be improved. Light can be extracted from almost the entire surface except the outer periphery of the upper surface of the light emitting element.

FIG. 8 is a perspective view showing a light emitting device having an array structure. FIG. 9 is a perspective view showing the inside of the light emitting device having the array structure shown in FIG. 8 (in a state where the light guide reflecting substrate 41 and the light receiving substrate 42 are separated). FIG. 10 is a sectional view taken along line XX of FIG. 8, and FIG. 11 is a plan view showing a part of a light receiving substrate 42 constituting the light emitting device. The same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted.

The light emitting device having the array structure includes a light guide reflecting substrate 41.
And a plurality of light emitting elements 20 and a light receiving substrate 42.

The light guide reflection substrate 41 includes the silicon substrate 9A. An SiO2 layer 15 and a nitride film 16 are laminated on substantially the entire upper surface and the entire lower surface of the silicon substrate 9A. An electrode 17 is formed along one side of the upper surface of the silicon substrate 9A (on the SiO2 layer 15 and the nitride film 16). The electrode 17 and the silicon substrate 9A are electrically connected through the hole (pinhole) 17a.

From the lower surface of the silicon substrate 9A, a plurality of recesses (having the same shape as the recesses 12 and 13 shown in FIGS. 1 to 3)
Are regularly arranged two-dimensionally. In FIG. 8, five concave portions are formed in the light guide reflection substrate 41. The light emitting element 20 is accommodated in each of the concave portions 12. The upper surface electrodes 25 of all the light emitting elements 20 housed in the recesses 12 are electrically connected to the electrodes 17 through the metal film 14 and the silicon substrate 9A.

A plurality of light extraction holes 18 communicating with the concave portions 12 and 13 are formed on the upper surface of the light guide reflection substrate 41. Recess 12
Most of the light emitted from the light emitting element 20 stored therein is directly reflected, partly reflected by the metal film 14, and then emitted to the outside through the light extraction hole 18.

The light receiving substrate 42 has a pn junction structure.
On the upper surface, an upper surface electrode (transparent electrode) 31 is formed at a position facing the light emitting element 20 (recess 12). Transparent electrode 31
An isolation groove 45 is formed from the upper surface of the light receiving substrate 42 toward the inside. The isolation groove 45 has such a depth as to divide the pn junction surface of the light receiving substrate 42. Thus, the light receiving substrate 42 is partitioned into a plurality of electrically insulated regions. Each of the divided areas functions as a single light receiving element.

The light receiving substrate 42 may be partitioned by inverting doping the portion corresponding to the isolation groove 45 of the light receiving substrate 42. The divided adjacent regions are electrically insulated from each other. This inversion doping is performed by ion implantation or diffusion into the light receiving substrate 42.

An SiO 2 layer 44 is formed on the p-type semiconductor layer 33 of the light receiving substrate 42 and inside the isolation groove 45. The upper electrode 31 is formed on the SiO2 layer 44, and is electrically connected to the p-type semiconductor layer 33 through pinholes (not shown) formed in the SiO2 layer 44 for each section. Part of the emitted light (visible light) of the light emitting element 20 is transmitted to the metal film 14 formed in the concave portion 12 of the light guide reflection substrate 41.
Reflected by the upper electrode 31 (transparent electrode) and Si
The light passes through the O2 layer 44 (SiO2 is transparent) and enters each of the opposing light receiving areas defined by the isolation grooves 45.

On one side of the light receiving substrate 42, an SiO 2 layer 44
A plurality of wiring patterns 43 are formed on the surface of the
It is connected to each of the plurality of upper surface electrodes 31 on the upper surface of 42 (see FIG. 11).

A plurality of wiring patterns 43 are provided for each pair of the light emitting element 20 and the light receiving element (one area defined by the isolation groove) together with the electrode 17 and the lower electrode 32 of the light receiving substrate 42. Connected to a control circuit (not shown) (the electrode 17 and the lower electrode 32 of the light receiving substrate 42).
Is common to all drive control circuits). Stability control of the light emission output of the light emitting elements 20 is performed independently for each light emitting element 20.

By employing an array structure, a large amount of light output is realized. In addition, since the light emission output is stably controlled for each light emitting element 20, it is possible to obtain uniform and high output light.

FIG. 12 is a perspective view of a projector using a light emitting device having a monitor mechanism. In FIG. 11, the structure of the light emitting device is the same as that shown in FIGS.

The light emitting device 50 (the lower surface electrode 32 of the light receiving element 30) is fixed to a mounting piece of the lead frame 52. Light emitting element
The lower electrode 26 of 20 and the upper electrode 31 of the light receiving element 30 are electrically connected to the lead frame 54 by wires. The upper surface electrode 25 of the light emitting element 20 is connected to the metal film 14, the light guide reflection substrate 10, and the electrode 17 on the upper surface of the light guide reflection substrate 10,
It is electrically connected to another lead frame 53 by a wire bonded to the electrode 17. Light emitting device 5
0, the mounting piece of the lead frame 52, the upper part of the lead frame 53, the upper part of the lead frame 54, and the wires are sealed in the mold resin 55. A Fresnel lens 51 is formed on the front surface of the mold resin 55.
The light emitted from the light emitting device 50 is condensed or collimated.

On both sides of the front surface of the mold resin 55 where the Fresnel lens 51 is formed, projections 55a and 55b are formed. The projections 55a and 55b are the Fresnel lenses 51
And is formed so as to protrude at the same height as the annular protrusion of the Fresnel lens 51 or a little more than that.

Since the light emitting element 20 has a high light extraction efficiency,
High output light can be emitted. Therefore, the projector using the light emitting device 50 similarly emits high-output light.
Part of the light (visible light) emitted from the light emitting element 20 is
And a light receiving signal from the light receiving element 30 is given to a drive control circuit (not shown) provided outside. The light emission output of the light emitting device 50 is stabilized.

FIG. 13 is a schematic diagram of an optical distance sensor using a light emitting device having a monitor mechanism. In FIG. 13, the structure of the light emitting device 60 is the same as that shown in FIGS.

This optical distance sensor is composed of a light projecting unit including a light emitting device 60 and a collimating lens 61, and a light receiving side lens.
62 and a light receiving section composed of a position detecting element 63. The light emitting unit and the light receiving unit are housed in a case 64. The light projected from the light projecting unit is collimated by the collimating lens 61 and projected from the exit window 65 opened in the case 64 toward the object b. The reflected light from the device under test b enters the position detecting element 63 of the light receiving unit from the light receiving window 66 opened in the case 64.

The distance from the case 64 to the measured object or the displacement of the measured object b is measured using the principle of triangulation. That is, the reflected light from the object b is
Since the position of incidence on 63 changes according to the position of the object b, the distance or the amount of displacement is calculated based on the output signal of the position detection element 63.

The light emitting element 20 (light emitting device 60) emits light having a small diameter to the outside. Since the diameter of the beam spot projected on the object to be measured b is reduced, the resolution is improved, and accurate distance detection can be performed. In addition, since high output light is emitted, detection over a long distance can be performed. The light emission output of the light emitting device 60 is stabilized by a drive control circuit (not shown) provided outside.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a light emitting device provided with a monitor mechanism, which corresponds to a sectional view taken along line II in FIG.

FIG. 2 is a longitudinal sectional view of the light emitting device taken along a plane different from the longitudinal section shown in FIG. 1 by 90 °, and corresponds to a section taken along line II-II in FIG.

FIG. 3 is a perspective view showing an outer shape of a concave portion formed on a light guide reflecting substrate constituting the light emitting device.

FIGS. 4 (A), (B), (C), (D), (E) and (F) are cross-sectional views showing steps for manufacturing a light-guiding reflective substrate.

FIGS. 5 (G), (H), (I), (J) and (K) are cross-sectional views showing a manufacturing process of a light-guiding reflective substrate and a process of mounting a light-emitting element in a concave portion of the light-guiding reflective substrate. FIG.

FIG. 6 is a perspective view showing another example of the surface-emitting type semiconductor light emitting device.

FIG. 7 is a perspective view showing still another example of the surface-emitting type semiconductor light emitting device.

FIG. 8 is a perspective view showing a light emitting device having an array structure.

9 is a perspective view showing the inside of the light emitting device having the array structure shown in FIG. 8;

FIG. 10 is a sectional view taken along line XX in FIG. 8;

FIG. 11 is a plan view showing a part of a light receiving substrate constituting the light emitting device shown in FIGS. 8 to 10;

FIG. 12 is a perspective view of a light projector using a light emitting device having a monitor mechanism.

FIG. 13 is a schematic sectional view of an optical distance sensor using a light emitting device having a monitor mechanism.

FIG. 14 is a schematic sectional view of a light emitting device having a conventional monitor mechanism.

FIG. 15 is a schematic sectional view showing another example of a light emitting device having a conventional monitor mechanism.

FIG. 16 is a cross-sectional view showing another example of a light emitting device having a conventional monitor mechanism.

[Explanation of symbols]

 10 Light-guiding reflective substrate 12, 13 Recess 14 Metal film 18 Light extraction hole 20 Surface-emitting type semiconductor light emitting device 27 Light emitting window 29 Transparent resin 30 Semiconductor light receiving device 50, 60 Light emitting device

Claims (4)

[Claims] An upper surface electrode is formed on an upper surface, and a lower surface electrode is formed on a lower surface. A surface emitting type light emitting element in which at least a part of the upper surface is a light emitting surface, and at least an upper part of the surface emitting type light emitting element are housed. A concave portion and a light extraction hole connected to the concave portion are formed, and a part of the light emitted from the light exit surface is guided to the outside through the light extraction hole.
A light guide / reflecting substrate having a light guide / reflecting surface formed so that another part is directed downward through the side of the surface emitting type light emitting element, and a lower surface of the surface emitting type light emitting element is joined to a part of the upper surface. A light emitting device comprising a monitor mechanism comprising: a light receiving element for receiving light traveling downward by the light guide reflection surface of the light guide reflection substrate. 2. A first concave portion for accommodating at least an upper portion of the surface-emitting type light emitting element, wherein the concave portion of the light guide / reflective substrate includes:
The first concave portion is connected to the light extraction hole, and is constituted by a second concave portion for guiding light emitted from the surface emitting type light emitting element to the light extraction hole, and a boundary between the first concave portion and the second concave portion. A step is formed in the portion, and at least a part of the upper surface electrode of the surface-emitting type light-emitting element accommodated in the storage portion is
A light emitting device comprising the monitor mechanism according to claim 1, wherein the light emitting device is in contact with the step portion. 3. The light emitting device according to claim 1, wherein a space between the front emission type light emitting element and the recess is filled with a transparent resin. 4. A light emitting device having a monitor mechanism having an array structure, wherein the light emitting device having the monitor mechanism according to claim 1 is two-dimensionally arranged on one substrate. apparatus.