JPH06244502A - Surface-emission laser apparatus and its manufacture - Google Patents

Abstract

PURPOSE:To provide a surface-emission laser apparatus for emitting light according to the incoming of light to a light-receiving conductive element equipped on the electrode side of respective surface-emission laser elements of a secondary laser array. CONSTITUTION:An n-type multilayer film 2 and clad layer 3 are laminated on a substrate 1, an active layer 4, clad layer 5 and cap layer 6 are laminated on the clad layer 3 in the order named; and current block layers 7a, 7b are laminated on the clad layer 3 in the mode of burying these layers. Also, flattening layers 8a, 8b are laminated on the surface of the cap layer 6 and current block layer 7b. Further, a multilayer film 13 is formed on the flattening layer 8b being the upper layer of the active layer 4; a collector 9, base 10, emitter 11 and contact layer 12 are laminated in the position on the flattening layer 8b separated from the multilayer film by a suitable length and a light transistor T is provided therein; and a wavelength filter 14 is formed in the center of the light transistor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface emitting laser device used in an optical information processing system and a manufacturing method thereof.

[0002]

2. Description of the Related Art The emergence of optical information processing systems is expected in the advanced information society of the near future. The optical information processing system is a system that maximizes the high speed of light and parallel propagation in space, and a surface emitting laser device is mentioned as a device for realizing this system.

The structure of a conventional surface emitting laser device will be described below. FIG. 20 is a schematic cross-sectional view showing the structure of a conventional embedded surface emitting laser device. This surface emitting laser device comprises an n-type semiconductor multilayer film 92, an n-type cladding layer 93, a p-type active layer 94 and a p-type on a substrate 91 of n-type GaAs by MOCVD (metal organic chemical vapor deposition). The clad layer 95
And a p-type cap layer 96 are stacked in this order to form a double hetero structure, and a p-type current block layer 97a is formed on the cladding layer 93 and an n-type current block is formed on the double hetero structure. Layers 97b are laminated and cap layer 96
A p-type current spreading layer 98a is stacked on the current blocking layer 97b. Contact layer 98 on current spreading layer 98a
b are stacked, and a multilayer film 99 is formed in the central portion on the contact layer 98b. Then, the p-type ohmic electrode 96 ₁ is formed on the contact layer 98 b so as to surround the multilayer film 99, and the n-type ohmic electrode 96 ₂ is formed on the lower surface of the substrate 1.

Further, the applicant of the present invention has published a self-aligned surface emitting laser device in 1991, Proceedings of Japan Society of Applied Physics, 11p-ZM-1. This is n on a n-type GaAs substrate.
Type semiconductor multi-layered film and p-type GaAs active layer are stacked. The central part of the n-type block layer stacked on the active layer is removed, and the p-type flat layer is regrown by LPE. It is a thing.

Further, the applicant of the present application has proposed a method of manufacturing a self-aligned surface emitting laser device by using the selective meltback method in Japanese Patent Laid-Open No. 63-157489.
In this surface emitting laser device, a mesa portion forming layer having a mesa portion in the central portion is laminated on a p-type GaAs substrate, and a current block layer is laminated so as to surround the mesa portion, and the mesa portion is melted. It is removed by the bag. A first clad layer is grown on the first clad layer, an active layer is formed on the first clad layer, and a second clad layer is laminated on the first clad layer. An internal current constriction structure is provided in which a current block layer is provided below the active layer. ing.

[0006]

SUMMARY OF THE INVENTION Such a surface emitting laser.
The device is between the substrate surface and the epitaxial growth layer surface.
Forming a resonator, current is confined in the active layer,
It has a structure that emits light. This surface emitting laser device
Are arranged two-dimensionally and the active regions of each element are electrically separated
The surface emitting laser device of the two-dimensional laser array is
A device is formed. FIG. 21 is a schematic view of this surface emitting laser device.
3 is a perspective view showing each element L driven by a power supply. ₁, L₁…But
It emits light independently.

In such a surface emitting laser device, laser elements can be formed into a two-dimensional array, or the laser elements and peripheral electronic circuits can be integrated, and the emitted light from the laser elements has a single wavelength property. Are better. From these, it is expected that the surface-emitting laser device will be applied to an optical information processing system. Therefore, the surface-emitting laser device is required to have a function of emitting light when light is incident and controlling the incident light. Has been done.

The present invention has been made on the basis of such a technical background. A surface emitting laser element is provided with a light receiving conductive element, and light is emitted from the surface emitting laser element when light is incident on the light receiving conductive element. By providing such a surface emitting laser device in a two-dimensional manner to cause a plurality of surface emitting laser elements to emit light, and further providing a wavelength filter on the light receiving conductive element. An object of the present invention is to provide a surface emitting laser device that emits a specific laser element and a manufacturing method thereof.

[0009]

A surface emitting laser device according to a first aspect of the present invention is a surface emitting laser device comprising a surface emitting laser element that applies a voltage to electrodes to inject a current into an active layer to emit light. A light-receiving conductive element that causes a current to flow in the active layer upon incidence of light is provided such that an electrode of the surface-emission laser device serves as an electrode of the light-receiving conductive element.

A surface emitting laser device according to a second aspect of the invention is a surface emitting laser device in which a plurality of surface emitting laser elements for emitting light by applying a voltage to electrodes to inject current into an active layer are two-dimensionally arranged. A plurality of light-receiving conductive elements for flowing a current to the active layer upon incidence of light are provided such that the electrodes of the surface-emitting laser elements are the electrodes of the light-receiving conductive elements.

A surface emitting laser device according to a third invention is the first invention.
Alternatively, in the second invention, the surface emitting laser element is provided on a substrate provided with the light receiving conductive element.

A surface emitting laser device according to a fourth aspect of the present invention is the second aspect.
In the invention, at least one of the electrodes forming a pair of the plurality of light-receiving conductive elements is common.

A surface emitting laser device according to a fifth invention is characterized in that, in the first or second invention, a wavelength filter having optical wavelength selectivity is provided in the light receiving conductive element.

A surface emitting laser device according to a sixth aspect of the present invention is the fifth aspect.
In the invention, a substrate having a wavelength filter is provided on the light receiving conductive element.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a surface emitting laser device, wherein a step of forming a surface emitting laser element in which a voltage is applied to an electrode and a current is injected into an active layer to emit light, and the light receiving conductive element is formed. A step of forming electrodes so as to serve as electrodes of the surface emitting laser element, a step of forming a substrate having a wavelength filter, and a step of providing the substrate on the light receiving conductive element by associating the wavelength filter with the light receiving conductive element. It is characterized by having.

[0016]

In the surface-emitting laser device and the method of manufacturing the same according to the present invention, the light-receiving conductive element causes a current to flow through the active layer of the surface-emitting laser element upon incidence of light, whereby the surface-emitting laser element emits light. Light can be output depending on the light incident on the. Further, by arranging a plurality of surface emitting laser elements provided with light receiving conductive elements in a two-dimensional manner, a plurality of lights are output, and a wavelength filter having wavelength selectivity is provided in the light receiving conductive element, and the light is transmitted through the filter. The wavelength information of the incident light can be converted into the information of the light emission pattern.

Further, a light receiving conductive element is formed on a submount substrate such as a Si substrate, a surface emitting laser element formed in a separate step is formed on this substrate, and an electrode of the surface emitting laser element and a light receiving element are formed. By connecting the electrodes of the conductive element, the manufacturing becomes easy. Further, the wavelength filter is formed in a separate step on a substrate such as glass which transmits light, and the substrate is provided on the light receiving conductive element, whereby the manufacturing is further facilitated.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a schematic cross-sectional view showing the structure of the surface emitting laser device of the first invention. In this surface emitting laser device, Ga _0.9 Al _0.1 is formed on an n-GaAs substrate 1.
As / n-type multi-layer film 2 formed by 25 pairs of AlAs are _{stacked, n-Ga 0.6 Al 0. 4} As cladding layer 3 is laminated thereon. P-GaA is formed on the clad layer 3.
s active layer 4, p-Ga _0.6 Al _0.4 As clad layer 5 and p-Ga _0.9 Al _0.1 As cap layer 6 are formed in this order, and the clad layer 3 is filled with these.
A p-GaAs current blocking layer 7a is stacked on top of the n-GaAs current blocking layer 7b.
Then, the surface of the cap layer 6 and the current blocking layer 7b is flattened layer 8a of p-Ga _0.6 Al _0.4 As is
A flattening layer 8b of p-Ga _0.9 Al _0.1 As is stacked on top of this.

On the flattening layer 8b above the active layer 4, a multi-layered film 13 formed of 4 pairs of SiO ₂ / TiO ₂ is formed, and the flattening layer 8b is separated from this by a proper length. At the upper position, p-GaAs collector 9, n-G
A base 10 of aAs and an emitter 11 of p-GaAs are laminated in this order, and Si is formed in the central portion on the emitter 11.
A wavelength filter 14 composed of 27 layers of O ₂ / TiO ₂ is formed, and a p-GaAs contact layer 12 is laminated on the emitter 11 so as to surround the wavelength filter 14. This collector 9, base 10, emitter 11 and contact layer 12
Thus, the phototransistor T which is the light receiving conductive element is configured. Then, on the side surface of the phototransistor T opposite to the multilayer film 13, and on the planarization layer 8b, the phototransistor T is formed.
The SiO ₂ layer 15 is provided at a position opposite to the multilayer film 13 with the SiO ₂ layer 15 interposed therebetween.
Are formed. Then, the p-type electrode 16 ₁ is formed on the SiO ₂ layer 15 and the contact layer 12, and the n-type electrode 16 ₂ is formed on the lower side of the substrate 1.

Specific numerical examples of the component composition, film thickness and carrier concentration of each layer of this surface emitting laser are shown below. n-type multilayer film 2 ... Ga _0.9 Al _0.1 As, 0.0627 μm, 1.
0 × 10 ¹⁸ cm ^{-3 /} AlAs, 0.0745 μm, 1.0 × 10 ¹⁸ cm ^-3 clad layer 3 ... n-Ga _0.6 Al _0.4 As, 0.5 μm,
1.0 × 10 ¹⁸ cm ^-3 active layer 4 ... p-GaAs, 1.0 μm, 4.0 × 10 ¹⁷ cm ^-3 clad layer 5 ... p-Ga _0.6 Al _0.4 As, 0.5 μm,
1.0 × 10 ¹⁸ cm ⁻³ Cap layer 6 ... p-Ga _0.9 Al _0.1 As, 0.3 μm,
1.0 × 10 ¹⁸ cm ^-3 Current blocking layer 7a ... p-GaAs, 0.8 μm, 1.0 ×
10 ¹⁸ cm ^-3 Current blocking layer 7b ... n-GaAs, 0.8 μm, 2.0 ×
10 ¹⁸ cm ^-3 Planarization layer 8a ... p-Ga _0.6 Al _0.4 As, 3.0 μm,
1.0 × 10 ¹⁸ cm ⁻³ Flattening layer 8b ... p-Ga _0.9 Al _0.1 As, 0.5 μm,
3.0 × 10 ¹⁸ cm ^-3 collector 9 ... p-GaAs, 0.2 μm, 5.0 × 10 ¹⁶ cm ^-3 base 10 ... and n-GaAs, 0.2 μm, 1.0 × 10 ¹⁸ cm ^-3 emitter 11 ... p-GaAs, 0.3 μm, 1.0 × 10 ¹⁷ cm ⁻³ Contact layer 12 ... p-GaAs, 0.2 μm, 1.0 × 10 ¹⁸
cm ^-3

A process of forming such a surface emitting laser device will be described below. 2 to 5 are schematic cross-sectional views showing the structure of the surface emitting laser device according to the first aspect of the invention at the production stage. First, MOCVD is performed on the n-GaAs substrate 1.
Method (metalorganic vapor phase method), 0.0627 μm Ga _0.9 A
The n-type multi-layer film 2 is formed of 25 pairs of _0.1 As / 0.0745 μm AlAs, and is composed of n-Ga _0.6 Al _0.4 As.
0.5 μm clad layer 3, p-GaAs 1.0 μm
m active layer 4, 0.5 made of p-Ga _0.6 Al _0.4 As
A clad layer 5 of μm, a cap layer 6 of 0.3 μm made of p-Ga _0.9 Al _0.1 As, and a GaAlAs layer m ₁ are laminated in this order. Then, as shown in FIG. 2, wet etching is performed using a sulfuric acid-based etchant to a depth that does not reach the cladding layer 3 of the active layer 4 to form a mesa portion on the end side from the center of the element.

Then, as shown in FIG. 3, the active layer 4 remaining around the mesa portion is removed by meltback to expose the cladding layer 3, and the LPE method (liquid phase epitaxial growth method) is applied to the cladding layer 3. By using the GaAlAs layer m ₁ as a mask, the mesa portion is embedded in the p-Ga layer.
A 0.8 μm current blocking layer 7a made of As and a 0.8 μm current blocking layer 7b made of n-GaAs are grown on the current blocking layer 7a.

Then, the GaAlAs layer m ₁ is removed, and p- is formed on the surfaces of the cap layer 6 and the current blocking layer 7b.
3.0 μm flattening layer 8 made of Ga _0.6 Al _0.4 As
a, a 0.5 μm flattening layer 8b made of p-Ga _0.9 Al _0.1 As, a 0.2 μm collector layer 9 made of p-GaAs, a 0.2 μm base layer 10 made of n-GaAs 10, p-
0.3 μm emitter layer 11 made of GaAs and p-Ga
A 0.2 .mu.m contact layer 12 of As is laminated in this order. As shown in FIG. 4, first, wet etching is performed up to the surface of the planarization layer 8b using a sulfuric acid-based etchant to form the phototransistor T at a position separated from the position corresponding to the active layer 4 by an appropriate length. Next, wet etching is performed up to the surface of the emitter layer 11 to remove the substantially central portion of the contact layer 12.

Then, as shown in FIG. 5, Si of 0.152 μm is formed at a position corresponding to the active layer 4 on the flattening layer 8b.
Multilayer film consisting of 4 pairs of O ₂ /0.096 μm TiO ₂ 13
And the wavelength filter 14 is formed on the exposed emitter layer 11 of the phototransistor T. The wavelength filter 14 has 13
27 of 70 Å SiO ₂ (L) and 830 Å TiO ₂ (H)
The layers are, for example, HLH · 2L (HL) ⁴ H · 4L · H
(LH) which are stacked in the order of ⁴ · 2L · HLH. FIG. 6 is a graph showing the transmission characteristics with respect to the wavelength of light of the wavelength filter 14 having such a configuration. The horizontal axis represents the wavelength of light and the vertical axis represents the transmittance. The wavelength filter 14 is
As shown in FIG. 6, light having a wavelength of 780 nm is selectively transmitted.

Next, as shown in FIG. 1, the SiO ₂ film 15 is located on the flattening layer 8b at a position opposite to the multilayer film 13 with the phototransistor T interposed therebetween, and on the side surface of the phototransistor T opposite to the multilayer film 13. Then, the p-type electrode 16 ₁ is formed on the SiO ₂ film 15 and the contact layer 12 at a position on the side. Then, an n-type electrode 16 ₂ on the lower side of the substrate 1.

The surface emitting laser device as described above includes the electrode 1
When a predetermined voltage is applied between 6 ₁ and 16 ₂ and light from the outside enters the wavelength filter 14 and a current flows from the phototransistor T to the active layer 4, light is emitted from the multilayer film 13. . At this time, light having a wavelength of 780 nm irradiates the phototransistor T, and the phototransistor T operates and emits light from the multilayer film 13 only when this light passes through the wavelength filter 14 having a high transmittance at the wavelength 780 nm and enters. It is like this.

Next, a second embodiment of the present invention will be specifically described with reference to the drawings showing the same. FIG. 7 is a schematic plan view showing the structure of the surface emitting laser device of the second embodiment. In the figure, La is the above-described surface-emitting laser device, which is composed of a laser element having a structure that includes a phototransistor Ta provided with a wavelength filter 14a for wavelength selection of 780 nm and a multilayer film 13a, and emits light from the multilayer film 13a. . Surface emitting laser device L
b, Lc, and Ld are provided with wavelength filters 14b, 14c, and 14d for wavelength selection of 815 nm, 850 nm, and 885 nm, respectively, and a phototransistor T having respective electrodes 17a, 17b, 17c, and 17d.
b, Tc and Td, and multilayer films 13b, 13c and 13d, and the surface emitting laser devices La and L are provided on the lower surface of the substrate 1.
Common electrodes are provided for b, Lc, and Ld. For example, 780 nm is provided in the phototransistors Ta, Tb, Tc and Td of the surface emitting laser device which is two-dimensionally arranged in a 2 × 2 array.
When the light D ₁ having the wavelength is applied, the light D ₁ is transmitted only through the wavelength filter 14a of the phototransistor Ta, and only the light emission from the multilayer film 13a is obtained. Also, the 780 nm light D ₁ and 88
When irradiated with light D ₂ having a wavelength of 5 nm, the phototransistor T
The light passes through the wavelength filters 14a and 14d of a and Td,
Light emission is obtained from the multilayer films 13a and 13d. By thus providing the wavelength filters having different wavelength selectivity, the wavelength information of the incident light can be converted into the information of the light emission pattern.

Next, a third embodiment will be specifically described with reference to the drawings showing the third embodiment. FIG. 8 is a schematic plan view showing the structure of the surface emitting laser device of the third embodiment. 7 is the same as that of FIG. 7 except that the electrodes 17 of the phototransistors Ta, Tb, Tc, and Td are common electrodes, and the description thereof is omitted. When the surface emitting laser device having such a structure is irradiated with the light D ₁ having a wavelength of 780 nm, for example, the light D ₁ passes through only the wavelength filter 14a of the phototransistor Ta, and only the light emission from the multilayer film 13a is obtained. . When the light D ₂ having a wavelength of 885 nm is applied, the light D ₂ is transmitted only through the wavelength filter 14d of the phototransistor Td, and light emission from the multilayer film 13d is obtained.
Further, when the light D ₁ having a wavelength of 780 nm and the light D ₂ having a wavelength of 885 nm are simultaneously irradiated, light emission from the multilayer films 13a and 13d can be obtained. In such a surface emitting laser device, an input electric signal by a voltage applied to one electrode terminal is converted into an optical signal, and the propagation direction of the optical signal is changed by the wavelength of the control light such as the lights D ₁ and D ₂ . It can be spatially controlled.

Next, a fourth embodiment will be specifically described with reference to the drawings showing the fourth embodiment. FIG. 9 is a schematic cross-sectional view showing the structure of the surface emitting laser device of the first invention. This surface emitting laser device includes a collector layer 9 ₂ , a base layer 10 ₂ and an emitter layer.
The phototransistor T ₂ composed of 11 ₂ and the contact layer 12 ₂ has an n-type electrode 16 on the side opposite to the side where the multilayer film 13 is provided.
Equipped with ₂ surfaces. Except for this, the surface emitting laser device is the same as the above-described one, and the corresponding portions are denoted by the same reference numerals and the description thereof will be omitted. In the surface emitting laser device having such a structure, the wavelength filter 14 ₂ formed on the n-type electrode 16 ₂ side
To light is incident, transmitted through the wavelength filter 14 _2, emits light to the incident direction in the same direction from the multilayer film 13.

When a surface emitting laser device of a two-dimensional laser array is formed using such a surface emitting laser device,
The wavelength information of the incident light in the same direction as the direction in which the light should be emitted can be transmitted, that is, the incident light can be incident from the opposite side without blocking the transmission path for transmitting the information. Further, the surface distance between the light emitting multilayer film 13 and the phototransistor T ₂ can be made shorter than the case where the phototransistor T ₁ is provided on the same side as the multilayer film 13, so that the surface emitting laser device is miniaturized. be able to.

Next, a fifth embodiment will be described with reference to the drawings showing this.
I will explain in detail. FIG. 10 shows the surface emitting laser of the first invention.
It is a typical sectional view showing the structure of the device. This surface emitting
The laser device includes a p-type electrode 16 on the same side as the multilayer film 13 for emitting light.
₁On top of the collector layer 9₁， Base layer 10₁, Emitter layer 11
₁And contact layer 12₁Phototransistor T composed of
₁And n-type electrode 16 on the opposite side₂On the surface, collector
Layer 9₂， Base layer 10₂, Emitter layer 11₂And contacts
Layer 12₂Phototransistor T composed of₂Is equipped with
It Other than this, it is similar to the surface emitting laser device of the first embodiment.
Therefore, the corresponding parts are designated by the same reference numerals and the description thereof is omitted.
It In the surface emitting laser device having such a structure, the p-type electrode
16₁Wavelength filter 14 formed on the side₁And n-type electrode 16₂
Wavelength filter 14 formed on the side₂Light is incident from and waves
Long filter 14₁, 14 ₂ Through the multi-layer film 13
Emits light.

When a surface emitting laser device of a two-dimensional laser array is formed using such a surface emitting laser device,
The wavelength information of more patterns can be converted into the information of the emission pattern.

Next, a sixth embodiment will be specifically described with reference to the drawings showing the sixth embodiment. FIG. 11A is a schematic front view showing the surface emitting laser device of the sixth embodiment, and FIG. 11B is a schematic plan view thereof. In the figure, reference numeral 21 denotes a 2 × 2 surface emitting laser device, which has the same structure as that of the two-dimensional surface emitting laser device of the present invention shown in FIG. 7 described above except that a wavelength filter is not provided in the phototransistor. . Surface emitting laser device
A glass substrate 22 having filters F ₁ and F ₁ formed on its surface and a glass substrate 23 having filters F ₂ and F ₂ formed on its surface 23
Are laminated so as to face the light receiving surface of the phototransistor provided in the surface emitting laser device 21.

FIGS. 12 (a) and 12 (b) show a filter on the surface.
F₁, F₁The formation process of the glass substrate 22 on which the
It is a schematic front view, and FIG. 12 (c) is a schematic plan view thereof.
is there. As shown in Fig. 12 (a), a glass substrate that transmits light
Λ on plate 22₁The wavelength filter that transmits the light of
It Photolithographically shown in Figures 12 (b) and 12 (c).
The position of the phototransistor of the surface emitting laser device 21.
Corresponding to the wavelength filter F ₁, F₁To form. this
Similarly to the glass substrate 22 formed as₂Through the light of
Pass wavelength filter F₂, F₂Formed glass base
The plate 23 and the plate 23 are laminated to form a wavelength filter substrate 24. That
On the surface emitting laser device 21 as shown in FIG. 11 (a).
The wavelength filter substrate 24 is mounted and adhered. This glass substrate
Adhesion of 22,23 and two-dimensional surface emitting laser device 21 and wavelength filter
For example, a UV curable resin is used for adhesion with the filter 24.

In the two-dimensional surface-emitting laser device manufactured as described above, since the wavelength filter for imparting wavelength selectivity to the light-receiving conductive element such as the phototransistor is formed on another substrate, the wavelength filter is a surface-emitting laser. It can be formed in a process different from that of the device and is easy to manufacture. By irradiating such a two-dimensional surface emitting laser device with light whose wavelength is controlled, it is possible to obtain light emission from a specific surface emitting laser element.

Next, a seventh embodiment will be specifically described with reference to the drawings showing the seventh embodiment. FIG. 13 is a schematic perspective view showing the structure of the surface emitting laser device of the seventh embodiment. Figure 14 (a)
13 is a sectional view taken along line IV-IV in FIG. 13, and FIG.
3 is a schematic plan view of an α portion of 3. FIG. As shown in FIG. 13, M is a conventional 2 × 2 surface-emitting laser device, in which a lower electrode 16 ₂ (on an Au pad P ₁ formed in the center of a semi-insulating Si substrate 31 serving as a submount substrate). 14 (a)) are brought into contact with each other to be mounted and formed. The surface emitting laser device M is M
₁ , M ₂ , M ₃ and M ₄ are electrodes formed on the uppermost layer
The isolation trenches A from 16 ₁ to the depth reaching the current block layer 7a are electrically independent.

Then, the phototransistor t is formed on the Si substrate 31.
₁ , t ₂ , t ₃ , and t ₄ are surface-emitting laser devices M ₁ ,
It is formed corresponding to each of M ₂ , M ₃ and M ₄ . As shown in FIG. 14 (b), the phototransistor t ₁ has the substrate 3
An n ⁺ -type collector 32 is formed in the inside 1, and an n-type collector 33, a p-type base 34, and an n-type emitter 35 are sequentially formed. Then, a collector electrode 38 is formed on the n ⁺ type collector 32, and an emitter electrode 37 is formed on the n type emitter 35 via the SiO ₂ film 36.
A wavelength filter 39 made of a dielectric multilayer film is laminated on the phototransistor t ₁ so that only light of a specific wavelength is transmitted. This wavelength filter 39 is
It is omitted in FIG. 14 (b). The emitter electrodes 37 of the phototransistors t ₁ , t ₂ , t ₃ and t ₄ thus formed and the surface emitting laser devices M ₁ , M ₂ , M ₃ and M 4, respectively.
Electrode 16 ₁ of each of ₄ and is, Au wires Y _1, Y _2,
They are connected by Y ₃ and Y ₄ .

In the two-dimensional surface emitting laser device having the above structure, the surface emitting laser element is formed on the Si substrate on which the phototransistor which is the light receiving conductive element is formed. The element can be formed in a step different from that of the element, which facilitates manufacturing. Further, when the light receiving conductive element is formed on the Si substrate, integration of electronic circuits such as the light receiving conductive element and the driving circuit becomes easy. By irradiating such a two-dimensional surface emitting laser device with light whose wavelength is controlled, it is possible to obtain light emission from a specific surface emitting laser element.

The above-mentioned two-dimensional surface emitting laser device is a junction up type, but another type of the seventh embodiment, that is, a junction down type two-dimensional surface emitting laser device will be described below.

FIG. 15 shows a junction down type 2 ×.
It is a typical perspective view which shows the structure of the two-dimensional surface emitting laser apparatus of 2. 16A is a schematic cross-sectional view as seen from the line VV of FIG. 15, and FIG. 16B is a schematic plan view of the β portion of FIG. As shown in FIG. 15, W is a conventional 2 × 2 surface-emitting laser device, which is mounted and formed in the center of a semi-insulating Si substrate 31 which is a submount substrate. Surface emitting laser device W
Are electrically isolated from each other by the separation groove B from the lowermost electrode 54 to the depth at which the current blocking layer 48 is reached by W ₁ , W ₂ , W ₃ and W ₄ .

One element of this two-dimensional surface emitting laser element, W _1, has an embedded DBR structure in which light is emitted from the substrate 41 side, as shown in FIG. 16 (a). First, a process of forming the surface emitting laser device W will be described. FIG. 17 is a schematic cross-sectional view showing the process of forming the surface emitting laser device W _{1. As} shown in FIG. 17A, n-GaAs is formed on the substrate 41 by the MOCVD growth method. A buffer layer 42 made of GaAs, a cladding layer 43 made of n-Ga _0.65 Al _0.35 As, an active layer 44 made of p-GaAs, and p-Ga.
Clad layer 45 made of _0.65 Al _0.35 As, p-Ga _0.94
A cap layer 46 made of Al _0.06 As and p-Ga _0.55 A
A mask layer 47 made of _0.45 As layer is laminated in this order.
Then, using a sulfuric acid-based etchant, wet etching is performed to a depth that does not reach the cladding layer 43 of the active layer 44,
A mesa portion is formed on the end side from the center of the element.

Next, as shown in FIG. 17B, the active layer 44 remaining around the mesa portion is removed by meltback to expose the cladding layer 43, and the LP layer is formed on the cladding layer 43.
By the E method (liquid phase epitaxial growth method), a current block layer 48 made of p-Ga _0.55 Al _0.45 As and a current block layer 49 made of n-Ga _0.7 Al _0.3 As are grown on the mesa portion so as to be embedded. Let

Then, after removing the mask layer 47, M again.
As shown in FIG. 17C, p-Ga _0.94 Al is formed on the cap layer 46 and the current blocking layer 49 by the OCVD growth method.
_A buffer layer 50 made of _0.06 As is formed, and Ga is formed thereon.
_A p-type semiconductor multilayer film 51 consisting of 25 pairs of _0.9 Al _0.1 As / Ga _0.4 Al _0.6 As is laminated, and p-GaA is formed thereon.
A contact layer 52 of s is formed.

Next, as shown in FIG. 17D, the central portions of the substrate 41 and the buffer layer 42 are opened, and SiO ₂ / TiO _{2 is formed.
A} dielectric multilayer film 53 consisting of 4 pairs of ₂ is formed, and further,
After the separation groove B is formed by wet etching to a depth reaching the current block layer 48, the n-type electrode 55 is formed on the lower side of the substrate 41 and the p-type electrode 54 is formed on the contact layer 52.
To form. Thus, the surface emitting lasers W ₁ , W ₂ , W
₃ , W ₄ are two-dimensionally formed in 2 × 2, the electrode 52 is formed for each of the surface emitting lasers W ₁ , W _2, ... And the electrode 55 is formed commonly for the surface emitting laser elements W ₁ , W ₂ . 18 and 19
Is a p-type semiconductor multi-layer film 51 and a dielectric multi-layer film to be a reflecting mirror
53 is a graph showing the respective reflection characteristics of 53, where the horizontal axis represents the wavelength of light and the vertical axis represents the reflectance. In this way, by making the reflectance of the dielectric multilayer film 53 lower than that of the p-type semiconductor multilayer film 51, it becomes possible to emit light from the substrate 41 side of the 2 × 2 two-dimensional surface emitting laser element W.

Specific numerical examples of the component composition, film thickness and carrier concentration of each layer of this surface emitting laser are shown below. n-type buffer layer 42 ... n-GaAs, 1.0 .mu.m cladding layer 43 ... n-Ga _0.65 Al _0.35 As, 3.0 .mu.m active layer 44 ... p-GaAs, 2.0 .mu.m cladding layer 45 ... p-Ga _0.65 Al _0.35 As, 0.5 .mu.m Cap layer 46 ... p-Ga _0.94 Al _0.06 As, 0.5 μm Mask layer 47 ... p-Ga _0.55 Al _0.45 As, 0.25 μm Current blocking layer 48 ... p-Ga _0.55 Al _0.45 As, 1.3-
1,5 μm current blocking layer 49 ... n-Ga _0.7 Al _0.3 As, ~ 0.
5 μm p-type buffer layer 50 ... n-Ga _0.94 Al _0.06 As, 0.5 μ
mp type semiconductor multilayer film 51 ... Ga _0.4 Al _0.6 As, 70 nm /
Ga _0.9 Al _0.1 As, 64 nm, 25 pair contact layer 52 ... p-GaAs, 0.3 μm dielectric multilayer film 53 ... SiO ₂ , 163 nm / TiO ₂ , 98 n
m, 4 pairs

As shown in FIG. 15, the 2 × 2 surface emitting laser element formed as described above is mounted and formed on the center of the Si substrate 31 with the electrode 55 side facing upward. Si substrate
Phototransistors t ₁ , t ₂ , t ₃ , t ₄ having wavelength filters, similar to the above-mentioned junction-up type surface-emitting laser device (FIG. 13), are formed on the surface of the surface-emitting laser device 31. The electrode 54 of W is the emitter electrode 37, 37
Connected with ... Further, the Au pad P ₂ formed on the Si substrate 31 and the uppermost electrode 55 of the surface-emission laser device W are Au.
Connected by wire Y ₅ .

In the two-dimensional surface-emitting laser device having such a structure, the light-receiving conductive element can be formed in a process different from the manufacturing process. Therefore, the manufacturing is easy, and when the light whose wavelength is controlled is irradiated, It is possible to obtain light emission from a specific surface emitting laser element.

The phototransistor t ₁ of the seventh embodiment,
Wavelength is provided in t ₂ ... filter 39 ... (Fig. 1
3, FIG. 15) shows a wavelength filter substrate 24 (FIG. 11) in which a wavelength filter is formed on the substrate in a separate process as shown in the sixth embodiment, on the phototransistors t ₁ , t ₂ . It may be provided in. At this time, a hole is formed in the central portion of the wavelength filter substrate 24, and the surface emitting laser element M or the surface emitting laser element W is positioned inside the hole so as not to contact the wavelength filter substrate 24.

In this embodiment, the wavelength filter 14 is made of Si.
The case of using the O ₂ / TiO ₂ multilayer film has been described, but the present invention is not limited to this, and other dielectric material multilayer films or Ga may be used.
A semiconductor multilayer film such as AlAs / AlAs, an organic dye or the like may be used.

Further, in this embodiment, as the light receiving conductive element,
Although the case where the phototransistor is used has been described, the present invention is not limited to this, and may be, for example, a photodiode such as a photodiode that allows a current to flow therethrough.

Further, in this embodiment, one light receiving conductive element is formed on the same electrode side of the surface emitting laser element.
The present invention is not limited to this, and a plurality of light-receiving conductive elements may be formed on the same electrode side so that the electrodes are connected in series. When a surface emitting laser device of a two-dimensional laser array is formed using such a surface emitting laser device, it is possible to convert wavelength information of more patterns into light emitting pattern information.

Furthermore, in the present embodiment, the structure of the surface emitting laser device has been described using the active layer embedded type structure, but the structure is not limited to this, and a self-aligned type may be used. Alternatively, it may have a structure in which the current blocking layer is formed on the lower layer side of the active layer.

[0053]

As described above, in the present invention, the light receiving conductive element provided in the surface emitting laser element is irradiated with light,
The surface emitting laser element emits light in response to the incident light. By arranging such a surface emitting laser device two-dimensionally and irradiating the light receiving conductive element with light to form a light emitting pattern, application to an optical information processing system becomes possible. Also, by providing a wavelength filter on the light receiving conductive element,
A specific laser element can be made to emit light, the wavelength information of the incident light can be converted to the information of the light emission pattern, and the surface emitting laser element is mounted on the substrate on which the light receiving conductive element is formed with the same electrodes. By providing the wavelength filter substrate on which the wavelength filter is formed on the light-receiving conductive element, the present invention has excellent effects such that the surface-emitting laser device can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a surface emitting laser device according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the structure of a surface-emission laser device according to a first embodiment at a manufacturing stage.

FIG. 3 is a schematic cross-sectional view showing the structure of the surface-emission laser device of the first embodiment at the manufacturing stage.

FIG. 4 is a schematic cross-sectional view showing the structure of the surface-emission laser device of the first embodiment at the manufacturing stage.

FIG. 5 is a schematic cross-sectional view showing the structure of the surface-emission laser device of the first embodiment at the manufacturing stage.

FIG. 6 is a graph showing the transmission characteristics of the wavelength filter with respect to the wavelength of light.

FIG. 7 is a schematic plan view showing the structure of a surface emitting laser device according to a second embodiment.

FIG. 8 is a schematic plan view showing the structure of a surface emitting laser device according to a third embodiment.

FIG. 9 is a schematic cross-sectional view showing the structure of a surface emitting laser device according to a fourth embodiment.

FIG. 10 is a schematic sectional view showing a structure of a surface emitting laser device according to a fifth embodiment.

11A is a schematic front view showing a surface emitting laser device according to a sixth embodiment, and FIG. 11B is a plan view thereof.

12 (a) and 12 (b) are schematic front views showing a process of producing the filter substrate according to the sixth embodiment, and FIG. 12 (c) is a schematic plan view thereof.

FIG. 13 is a schematic perspective view showing a surface emitting laser device of a seventh embodiment.

14A is a sectional view taken along line VI-VI in FIG. 13, and FIG. 14B is a schematic plan view of α.

FIG. 15 is a schematic perspective view showing another type of surface emitting laser device of the seventh embodiment.

16 (a) is a cross-sectional view taken along line VV of FIG. 15, and FIG. 16 (b) is a schematic plan view of β.

FIG. 17 is a schematic cross-sectional view showing the process of forming a two-dimensional surface emitting laser device according to the seventh embodiment.

FIG. 18 is a graph showing reflection characteristics of a p-type semiconductor multilayer film.

FIG. 19 is a graph showing reflection characteristics of a dielectric multilayer film.

FIG. 20 is a schematic cross-sectional view showing the structure of a conventional surface emitting laser device.

FIG. 21 is a schematic perspective view showing the structure of a two-dimensional laser array.

[Explanation of symbols]

1,41 Substrate 3,43 Clad layer 4,44 Active layer 5,45 Clad layer 6,46 Cap layer 7,48 Block layer 12,52 Contact layer 13,51 Multilayer film 14 Wavelength filter 16 ₁ , 16 ₂ , 54, 54, 55 electrode 24 wavelength filter substrate T, t phototransistor L, M, W surface emitting laser device

Claims (7)

[Claims] 1. A surface emitting laser device comprising a surface emitting laser element which applies a voltage to an electrode and injects a current into the active layer to emit light. In the surface emitting laser device, a light receiving conductive element which causes a current to flow into the active layer upon incidence of light. Is provided so that the electrode of the surface emitting laser element serves as the electrode of the light receiving conductive element. 2. A surface emitting laser device in which a plurality of surface emitting laser elements, which emits light by injecting a current into an active layer by applying a voltage to an electrode, are two-dimensionally arranged. A surface-emitting laser device comprising a plurality of light-receiving conductive elements through which an electric current is passed such that the electrodes of the surface-emitting laser elements are electrodes of the light-receiving conductive element. 3. The surface emitting laser element is provided on a substrate provided with the light receiving conductive element.
Alternatively, the surface emitting laser device according to item 2. 4. The surface emitting laser device according to claim 2, wherein at least one electrode of the pair of electrodes of the plurality of light receiving conductive elements is common. 5. A wavelength filter having optical wavelength selectivity,
3. The surface emitting laser device according to claim 1, wherein the surface emitting laser device is provided on the light receiving conductive element. 6. The surface emitting laser device according to claim 5, wherein a substrate having a wavelength filter is provided on the light receiving conductive element. 7. A process of forming a surface emitting laser element which applies a voltage to an electrode and injects a current into an active layer to emit light, and a light receiving conductive element, the electrode being an electrode of the surface emitting laser element. And a step of forming a substrate having a wavelength filter, and a step of providing the substrate on the light-receiving conductive element by associating the light-receiving conductive element with a wavelength filter. Production method.