JP2002353561A - Surface-emitting laser and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-emitting laser that can be reduced in element resistance and threshold current and can be properly integrated with another device by removing its substrate, and to provide a method of manufacturing the laser. SOLUTION: This surface-emitting laser has a resonator structure, which is constituted by laminating at least a first-conductivity first multilayered semiconductor mirror layer 103, a first-polarity contact layer 105, an active layer 107, and a second-polarity second multilayered semiconductor mirror layer 111 upon a substrate 101 in this order or in the reverse order. The contact layer 105 is formed by alternately laminating semiconductor layers 105b, which are high in carrier concentration, and semiconductor layers 105a which are low carrier concentration upon another and electrically connected to the side of a electrode 115.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface emitting laser device used as a light source for laser beam recording or magneto-optical recording, a light source for optical interconnection, optical information processing, parallel optical recording, and the like, and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art A vertical cavity surface emitting laser (Verti) is known.
cal Cavity SurfaceEmitting
Laser, VCSEL) have many advantages over edge-emitting lasers, such as lower manufacturing cost, higher manufacturing yield, and easier two-dimensional arraying. , Development is underway.

A surface-emitting laser generally comprises a semiconductor multilayer mirror arranged above and below an active layer to form a resonator. In particular, a surface-emitting laser having a structure in which both p and n electrodes are provided on the surface side. Lasers are attracting attention. This structure has the following advantages.

(1) Since a lateral current injection structure can be realized, the use of a semiconductor multilayer mirror having a high resistance as a current injection path can be avoided. (2) Mounting by flip chip bonding on a circuit board on which wiring, ICs, light receiving elements, etc. are mounted becomes possible.

[0005] An example of lateral current injection is disclosed in, for example, JP-A-08-181384. A schematic diagram of this example is shown in FIG. On a GaAs substrate 1010, an n-type semiconductor multilayer mirror 1020, an active layer 102
1. It is formed by laminating p-type semiconductor multilayer mirrors 1022.
One layer in the vicinity of the active layer 1021 of the p-type semiconductor multilayer mirror 1022 is a p-type GaAs layer 1017 having an optical thickness of an odd multiple of 1/4 wavelength (however, greater than 1). 1040 is formed so as to be in contact with the GaAs layer 1017. The n-side electrode 1041 is formed to be in contact with the n-type semiconductor multilayer mirror 1020. In this example, the oscillation wavelength is GaAs substrate 10
It is transparent to 10 and extracts light from the substrate side. When the GaAs layer 1017 is a normal mirror (1
/ 4 wavelength), there is an advantage that the processing accuracy at the time of etching is eased and the resistance is reduced.

An example of flip chip bonding is disclosed, for example, in Japanese Patent Application Laid-Open No. 07-283486. FIG. 10 shows a schematic diagram of this example. The electrode 2006 on the surface emitting laser substrate side and the wiring 2008 on another substrate 2007 are bonded by solder bumps 2009. In this example, AlGaAs is used as the substrate 2001.
s is used, and light L can be extracted from the substrate side in a wavelength band of 830 nm.

[0007]

However, in the above-described conventional lateral current injection type surface emitting laser device,
To reduce the contact resistance with the p-side electrode 1040, G
It is necessary to increase the carrier concentration of the aAs layer 1017,
As a result, there is a drawback that light absorption there increases, causing an increase in threshold current and a decrease in light output. Further, since no special measures are taken for the n-type semiconductor multilayer mirror 1020, there is a limit to a reduction in contact resistance with the n-side electrode 1041. Further, this example cannot be applied to a surface emitting laser in a wavelength band such as a wavelength of 780 nm where the GaAs substrate is not transparent. For example, a GaAs layer 1017
If this is applied to this wavelength band as it is, light cannot be oscillated due to large light absorption. When the Al composition is increased to 0.3 or more, the film becomes transparent. However, there is a problem that it is difficult to obtain an ohmic contact. In addition, GaAs
Since light cannot pass through the substrate 1010, light cannot be extracted from the substrate side.

Further, in the above-mentioned example of flip chip bonding, both the p-side electrode and the n-side electrode are formed on the surface. However, there is no special contrivance for the contact layer. There is a limit. Further, the cost of the AlGaAs substrate 2001 is higher than that of the GaAs substrate. When the substrate is replaced with a GaAs substrate, it is necessary to remove the substrate depending on the wavelength band, but this point is not considered in this example.

In view of these problems, an object of the present invention is to
Element resistance can be reduced, low threshold current can be achieved, and
It is an object of the present invention to provide a surface emitting laser device capable of removing a substrate and having excellent integration with other devices, and a method of manufacturing the same. n, It is an object of the present invention to provide a surface emitting laser device having such features in a surface emitting laser device capable of easily providing both electrodes, and a method of manufacturing the same.

[0010]

In order to achieve the above object, a surface emitting laser device according to the present invention comprises at least a first semiconductor multilayer mirror layer having a first polarity on a substrate;
A contact layer of a first polarity, an active layer, a second layer of a second polarity;
A semiconductor multilayer mirror layer having a resonator structure formed by stacking layers in this order or in reverse order, wherein the first polarity contact layer includes at least one semiconductor layer having a high carrier concentration and at least one layer The semiconductor device has a structure in which semiconductor layers having a low carrier concentration are alternately stacked, and the contact layer having the first polarity and the electrode on the first pole side are electrically connected. More specifically, the composition and film of each layer constituting the contact layer of the first polarity such that the semiconductor layer having a high carrier concentration is located at a node of a standing wave of an electric field present in the resonator. It is characterized in that the thickness is set. According to the above structure, the absorption of light is reduced by arranging a semiconductor layer having a high carrier concentration, that is, a semiconductor layer having a large light absorption at a node of a standing wave of an electric field,
In addition, low contact resistance can be realized.

[0011] The first polarity contact layer may include:
It is a stacked structure of AlGaAs having different Al compositions, and a semiconductor layer with a high carrier concentration can have a smaller Al composition than a semiconductor layer with a low carrier concentration. As a result, a semiconductor layer having a high carrier concentration can be converted to an A layer having a small Al composition.
Ohmic contacts can be easily obtained by using lGaAs.

A current confining structure formed by oxidizing an AlGaAs layer including a semiconductor layer having an Al composition of at least 0.9 or more may be provided in the vicinity of the active layer. According to this structure, a surface emitting laser with a lower threshold current can be realized.

Further, a second contact layer having a second polarity, having a structure in which at least one semiconductor layer having a high carrier concentration and at least one semiconductor layer having a low carrier concentration are alternately laminated, is formed between the active layer and the second layer. A configuration inserted between the two semiconductor multilayer mirror layers can be adopted. The second contact layer of the second polarity may be configured similarly to the first contact layer of the first polarity. According to this structure, p and n
In both cases, a surface emitting laser capable of lateral current injection can be realized. In particular, on the p-side, the p-type semiconductor multilayer mirror can be bypassed, so that the effect of reducing the resistance is high.

Further, it is possible to have a post shape of a laminated structure including at least the active layer and the second or first semiconductor multilayer mirror layer. In this configuration, a second or first pole-side electrode electrically connected to a second or first semiconductor multilayer mirror is provided on the uppermost surface of the first post having two or more of the post shapes. Is formed, and on the uppermost surface of the second post, a first or second pole side electrode electrically connected to a contact layer of the first or second polarity has a side surface of the second post. A configuration formed in a round shape can be adopted. According to this structure, p and n
Since the heights of the two electrodes can be made substantially equal, mounting on another substrate becomes easy.

Further, the resonator structure on the substrate is bonded to another substrate on which electric wiring is provided at a position opposed to both electrodes of the first polarity and the second polarity, with the front surface side as the bonding surface. In addition, a configuration in which the first polarity electrode, the second polarity electrode (that is, the p-side electrode and the n-side electrode), and the electric wiring are electrically connected may be employed. More specifically, the resonator structure on the substrate and another substrate are electrically and mechanically bonded by solder bumps.

Further, the substrate may be removed while leaving the semiconductor layer forming the resonator in the resonator structure on the substrate. With this structure, light can be extracted from the back side (the side where the substrate was) even in the wavelength band absorbed by GaAs.

Further, the another substrate may be made of AlN. According to this structure, heat dissipation is improved.

Further, the another substrate is a Si substrate, on which electric wiring and a light receiver are formed,
It is possible to adopt a configuration in which the light receiver is arranged at a position where the light emitted from the surface side of the resonator can be received. With this structure,
A surface emitting laser device with a light quantity monitor can be realized.

Further, the another substrate may be a Si substrate, and an electric wiring and an electronic circuit may be integrated on the Si substrate. With this structure, a surface emitting laser device including a control or driving IC can be realized.

Further, a method of manufacturing a surface emitting laser device according to the present invention for achieving the above object, comprises the steps of: providing a first semiconductor multilayer mirror layer having a first polarity, a contact layer having a first polarity; Forming a resonator structure by laminating the active layer and the second semiconductor multilayer mirror layer of the second polarity in this order or in reverse order, and forming an active layer until the contact layer of the first polarity is exposed. Etching the layer, the second or first semiconductor multilayer mirror layer to form a post shape,
Forming a first pole side electrode on the first polarity contact layer or on the first polarity contact layer and the first semiconductor multilayer mirror layer, and on the second semiconductor multilayer mirror or substrate Forming a second pole-side electrode on the back surface of
It is characterized by including. According to this manufacturing method, the surface emitting laser device of the present invention having the above configuration can be easily manufactured.

The step of obtaining ohmic contact with the first pole-side electrode and the step of obtaining ohmic contact with the second pole-side electrode can be performed simultaneously or separately. If they are performed simultaneously, the manufacturing method is simplified. In the case where they are performed separately, the electrodes can be appropriately heated according to the respective electrode materials, so that an ohmic contact can be suitably used for each electrode.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of a surface emitting laser device according to the present invention will be described with reference to an example in which an n-type GaAs substrate is used and the oscillation wavelength is 780 nm. The structure will be described while explaining the manufacturing method.

On an n-type GaAs substrate, n-Al_0.9G
a_0.1As / n-Al_0.3Ga _0.7Consists of As
First semiconductor multilayer mirror layer, n-type feature of the present invention
Including contact layer, active layer, and Al-containing semiconductor layer
Type current confinement layer, p-Al_{0. 3}Ga_0.7As / p-A
l_0.9Ga_0.1A second semiconductor multilayer film made of As
Are stacked to form a resonator structure.

The contact layer has a carrier concentration of 6 × 10
¹⁸cm^-3N-Al_0.2Ga _0.8As and carry
A concentration 2 × 10¹⁸cm^-3N-Al_0.3Ga
_0.7As are alternately laminated. In addition,
Carrier concentration n-Al_0.2Ga _0.8As is a resonator
To be located at the node of the standing wave of the electric field existing inside
The thickness of each layer constituting the contact layer is set
The contact layer as a whole, for example, has a two-wavelength optical
Have a thickness.

Next, until the contact layer appears on the surface (in this case, it is preferable that the layer with a high carrier concentration appears on the surface, but either the layer with a high carrier concentration or the layer with a low carrier concentration appears on the surface). Is difficult to control, but
When heating to obtain an ohmic contact, this portion is alloyed to have a low resistance, so that any layer may appear and an ohmic contact can be obtained without any problem.) Etching the laminated structure to form a post, The current confinement layer is oxidized from the side to form a current confinement structure.

Next, A is formed on the contact layer as an n-side electrode.
A uGe / Au electrode is formed, and a Cr / Au electrode having a light extraction window at the top of the post is formed as a p-side electrode. Thereafter, heating is performed to obtain an ohmic contact.
As the electrode material, any material can be used as long as an ohmic contact can be obtained.

In the surface emitting laser having such a configuration, the resistance at the time of lateral current injection can be reduced by increasing the thickness of the contact layer, and the carrier concentration is high and the Al composition is low in order to easily obtain an ohmic contact. AlGaAs layer (the carrier concentration is 6 × 10 ¹⁸ cm)
^-3 n-Al _0.2 Ga _0.8 As) can suppress an increase in contact resistance. Further, AlGaAs having a high carrier concentration and a small Al composition
Although the layer has a high light absorptance, an increase in absorption can be suppressed by arranging this semiconductor layer at a node of a standing wave of an electric field existing in the resonator.

Although an n-type GaAs substrate is used in this example, a semi-insulating GaAs substrate or the like may be used.

Further, a p-type first semiconductor multilayer mirror layer, a p-type contact layer, and a p-type semiconductor layer containing an Al-containing semiconductor layer are formed on a p-type GaAs substrate or a semi-insulating GaAs substrate.
The resonator structure may be formed by laminating each of a current confining layer, an active layer, and an n-type second semiconductor multilayer mirror layer. In this case, the current can be injected by bypassing the high-resistance p-type semiconductor multilayer mirror, so that the effect of reducing the resistance is further enhanced.

Further, a configuration may be employed in which p-type and n-type contact layers are inserted above and below the active layer. According to this structure, it is possible to realize a surface emitting laser capable of injecting a lateral current in both p and n.

Further, an n-type or p-type first semiconductor multilayer mirror layer is formed on an n-type or p-type GaAs substrate.
An active layer, a p-type current confinement layer including an Al-containing semiconductor layer (this layer comes between the p-type first semiconductor multilayer mirror layer and the active layer in the case of a p-type GaAs substrate), p The resonator structure may be formed by laminating layers of a type or n-type contact layer and a p-type or n-type second semiconductor multilayer mirror layer. In this case, n-type or p-type GaAs
An embodiment in which an n-side or p-side electrode is formed on the back surface of the s substrate may be employed.

Of course, A which is transparent to the oscillation wavelength
An lGaAs substrate may be used. Also, an example of the current confinement structure by Al selective oxidation is shown, but the invention is not limited to this. For example, a high resistance region may be formed by ion implantation.

Further, one of the two or more post shapes produced at the same time may be used as a laser element, and the rest may be used as dummy posts. For example, an n-side electrode is disposed on the outermost surface of the laser element, and a p-side electrode electrically connected to the contact layer is formed on the outermost surface of the dummy post so as to extend around the side surface of the dummy post. Place it. According to this structure, the heights at which both the p and n electrodes are located are substantially equal, so that mounting on another substrate is easy and the yield is improved.

As the other substrate, a substrate having a high thermal conductivity, for example, an AlN substrate on which electric wiring is provided, or a Si substrate on which a photodetector and an electronic circuit are integrated can be used.

As a method of bonding to another substrate, for example,
It is possible to heat the solder bumps to form an alloy, to use a conductive adhesive or an anisotropic conductive adhesive (an adhesive that can be bonded by realizing conductivity only in the direction perpendicular to the bonding interface), Alternatively, solid-phase joining may be performed.

In the above embodiment, the wavelength is 780 nm
It is obvious that the composition, thickness and number of layers of each layer may be appropriately set according to the wavelength to be set.

[0037]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) A first embodiment of a surface emitting laser device according to the present invention will be described with reference to FIGS.
FIG. 1A is a sectional view of a surface emitting laser device according to the present invention. FIG. 2 is a view showing a manufacturing process.

First, the manufacturing process will be described with reference to FIG.
On an n-GaAs substrate 101, n-Al _0.9 Ga
_0.1 As (low refractive index layer 103b) / n-Al _0.3 G
a _0.7 As (high-refractive-index layer 103a) including an n-type semiconductor multilayer mirror layer 103 having 39.5 periods, an n-type contact layer 105, an active layer (high-refractive-index layer) 107, and an Al-containing semiconductor layer A p-type current confinement layer (low refractive index layer) 109;
p-Al _0.3 Ga _0.7 As (high refractive index layer 111a)
/ P-Al _{0 . 9} Ga _0.1 As (low refractive index layer 111
b) p-type semiconductor multilayer mirror layer 1 having 29.5 periods
11. The layers of the p-type contact layer 112 made of GaAs having a thickness of 50 ° are stacked to form a resonator structure (FIG. 2A).

Next, while leaving a post-shaped light emitting region, n
The semiconductor layer is dry-etched by reactive ion etching using Cl gas until the mold contact layer 105 is exposed on the surface (FIG. 2B). The light emitting area has a diameter of 2
It was a column of 0 μm.

Next, the insulating layer 110 is formed by oxidizing the current confinement layer 109 (FIG. 2C). The insulating layer 110 was formed such that the central current confinement region had a diameter of 5 μm. The oxidation conditions are as follows: 390 ° C., 7
Minutes.

Finally, Au is formed on the n-type contact layer 105.
An n-side electrode 115 made of Ge / Au is formed, and a diameter of 7 μm is formed on the uppermost p-type contact layer 112 of the post.
A p-side electrode 113 made of Cr / Au having a light extraction window is formed (FIG. 2D). Thereafter, both electrodes were heated to 375 ° C. to obtain ohmic contacts.

N-type contact layer 105, active layer 10
7. Regarding the configuration of the p-type current confinement layer 109, FIG.
This will be described in detail with reference to FIG.

The n-type contact layer 105 has a carrier concentration
Degree 6 × 10¹⁸cm^-3N-Al _0.2Ga_0.8A
s (105b) and carrier concentration 2 × 10¹⁸cm^-3of
n-Al_0.3Ga_0.7As (105a) alternately
The layer 105b has a thickness of 4.5 cycles.
Each layer is 200 °, and the layer 105a is 464 ° at both ends,
The other three layers are 928 °. With such a configuration
(The optical thickness of the entire contact layer 105 is two wavelengths.
), High carrier concentration and low Al composition
The layer 105b, which has a large absorption due to the fact, is formed in the resonator.
It is located at the node of the standing wave of the existing electric field.
You.

The active layer 107 is composed of Al _0.12 Ga _0.0.2 having a gain peak at a wavelength of 780 nm _{. 88} As (well layer)
/ Al _0.3 Ga _0.7 As (barrier layer) triple quantum well 107b was sandwiched between AlGaAs carrier block layers 107a in which the Al composition was gradually changed from 0.3 to 0.6. The thickness of each of the layers 107a and 107b was designed so that the optical thickness of the entire active layer 107 was one wavelength.

The p-type current confinement layer 109 includes a p-AlAs layer (thin layer) 109b having a high oxidation rate and a p-Al _0.9 Ga _0.1 As layer (thick layer) in which oxidation hardly proceeds. 109a. Current confinement layer 10
9 each layer 10 so that the overall optical thickness is 1/4 wavelength
The thicknesses of 9a and 109b were designed.

With such a structure, layers (layers 105b and 109b) which cause a loss due to scattering and absorption
Are located at the nodes of the standing wave of the electric field, and the active layer 107b that gives the gain is located at the antinode of the standing wave. Therefore, it is possible to operate the laser device of this embodiment at a low threshold current. Further, the n-type contact layer 10
By increasing the optical thickness of No. 5 to two wavelengths, the resistance at the time of lateral current injection is reduced, and an AlGaAs layer 105b having a high carrier concentration and a small Al composition is inserted in order to easily obtain an ohmic contact. As a result, an increase in contact resistance can be suppressed. FIG.
In the laminated structure shown in FIG. 2B, high-refractive-index layers and low-refractive-index layers are arranged alternately except for the contact layer 105.

When the surface emitting laser device according to the present embodiment was operated, the threshold current of the laser was 1.5 mA.
An optical output of 3 mW was obtained at a current of 8 mA. At this time, the oscillation wavelength was 782 nm, and the voltage was 2.4 V. For comparison, an n-type contact layer was formed using n-Al _0.2 G having a carrier concentration of 6 × 10 ¹⁸ cm ^−3.
When a device having a single layer structure of a _0.8 As was manufactured and operated, the threshold current was increased to 2.8 mA. Furthermore, the current required to obtain a light output of 3 mW is 14 m
A, and the operating voltage at that time was 2.6 V, and the characteristics deteriorated. Therefore, the effectiveness of this example was confirmed.

(Second Embodiment) A second embodiment of the surface emitting laser device according to the present invention will be described with reference to FIGS.
FIG. 3 is a sectional view of the surface emitting laser device according to the present embodiment.
FIG. 4 is a diagram showing a manufacturing process. In this embodiment, the p-side also has a lateral current injection structure.

The manufacturing process will be described with reference to FIG. n-G
a-As _0.9 Ga _0.1 As on the aAs substrate 201
/ N-Al _{0. 3} Ga _0.7 As39.5 n-type semiconductor multi-layer mirror 203 comprising periodic, n-type contact layer 205, the active layer 207, Al-containing semiconductor layer laden p-type current confinement layer 209, p-type contact layer 211, pA
l _0.3 Ga _0.7 As / p-Al _0.9 Ga _0.1 A
p-type semiconductor multilayer mirror layer 21 having s29.5 periods
P-type contact layer 21 made of 3,50 ° GaAs
4 are laminated to form a resonator structure (FIG. 4).
(A)).

Next, etching is performed twice to form a two-stage post shape in which the n-type contact layer 205 and the p-type contact layer 211 are exposed on the surface (FIG. 4).
(B)). The outer post had a cylindrical shape with a diameter of 40 μm, and the inner post had a diameter of 20 μm.

Next, the insulating layer 210 is formed by oxidizing the current confinement layer 209 (FIG. 4C). The insulating layer 210 was formed such that the central current confinement region had a diameter of 5 μm. The oxidation conditions are as follows: 390 ° C., 7
Minutes.

Finally, Au is formed on the n-type contact layer 205.
An n-side electrode 217 made of Ge / Au is formed, and a p-side electrode 215 made of Cr / Au is formed so as to cover the uppermost portion of the inner post and the p-type contact layer 211 (FIG. 4D). ). The p-side electrode 215 is provided with a light extraction window having a diameter of 7 μm. Thereafter, the resultant was heated to 375 ° C. to obtain an ohmic contact.

N-type contact layer 205, active layer 20
7. The layer configuration of the p-type current confinement layer 209 is the same as that of the contact layer 105, the active layer 107, and the p-type current confinement layer 109 in the first embodiment. Also, the p-type contact layer 21
Numeral 1 indicates that the polarity of each layer of the contact layer 105 is replaced with p-type.

By adopting such a configuration, it is possible to perform the current injection by bypassing the p-type semiconductor multilayer mirror 213 having high resistance, in addition to the effect similar to that of the first embodiment. Resistance has become possible.

When the surface emitting laser device according to the present embodiment was operated, the threshold current of the laser was 1.5 mA.
An optical output of 3 mW was obtained at a current of 8 mA. At this time, the oscillation wavelength was 782 nm, and the voltage was 2.36 V.

(Third Embodiment) A third embodiment of the surface emitting laser device according to the present invention will be described with reference to FIG. FIG.
1 is a sectional view of a surface emitting laser device according to the present embodiment. In the present embodiment, one of the two post shapes of the same layer structure produced at the same time is used as a laser element, and the other is used as a dummy post. The layer configuration and the manufacturing process are almost the same as those of the first embodiment, and the detailed description is omitted. The same members as those in the first embodiment are denoted by the same reference numerals.

In FIG. 5, the left post is the laser element, and the right post is the dummy post 450. Except for the uppermost surface of the laser element and a part of the n-type contact layer 105 (near the dummy post 450), the insulating layer 41 made of SiN _x
1 is formed. Also, a p / P made of Cr / Au having a light extraction window having a diameter of 7 μm at the uppermost part of the laser element.
A side electrode 415 is formed, and an n-side electrode 417 made of AuGe / Au is formed so as to cover the dummy post and a part of the n-type contact layer 105.

With this structure, the heights at which the p and n electrodes 415 and 417 are located can be made substantially equal. This structure is advantageous when mounting by flip-chip bonding on another substrate provided with wiring, and mounting can be easily performed with high yield.

(Fourth Embodiment) A fourth embodiment of the surface emitting laser device according to the present invention will be described with reference to FIG. The present embodiment is an example in which the surface emitting laser device according to the third embodiment is mounted on another substrate with wiring. The layer structure and the manufacturing process are almost the same as those of the first and third embodiments, and the detailed description is omitted. The same members as those in the first and third embodiments are denoted by the same reference numerals. However, a window for extracting light is not provided in the p-side electrode 416.

In FIG. 6A, 601 is an AlN substrate, 603 and 605 are wires connected to the p-side and n-side electrodes, respectively, and 607 is a solder bump made of AuSn.

The surface emitting laser device shown in the third embodiment is turned upside down, aligned and arranged on the substrate 601, and heated to melt the solder bumps 607 and bond them (FIG. 6B )).

Further, the entire surface of the GaAs substrate 101 is removed by etching with a mixed solution of ammonia and hydrogen peroxide (FIG. 6C). Reference numeral 650 in FIG. 6C is a dummy post. Although not shown in the figure, an etch stop layer made of AlAs is inserted between the GaAs substrate 101 and the n-type semiconductor multilayer mirror layer 103, so that the GaAs substrate 101 can be etched with a high yield. It is like.

In this embodiment, both the p and n electrodes 41
Since the heights of 6, 417 are uniform, the surface emitting laser device can be mounted on another substrate without tilting, and the production yield is improved.

Further, since the thermal conductivity of AlN 601 is high, the heat dissipation is improved, and light of 780 nm can be extracted from the back side (the side from which the substrate 101 is removed).

(Fifth Embodiment) A fifth embodiment of the surface emitting laser device according to the present invention will be described with reference to FIG. This embodiment is an example in which the surface emitting laser device according to the third embodiment is mounted on another substrate on which the light receiving element is integrated. Layer structure,
The manufacturing process is almost the same as in the first, third and fourth embodiments, and the detailed description is omitted. The same members as those in the first and third embodiments are denoted by the same reference numerals.

In FIG. 7, the center post is the laser element, and the right post 750 is the n-type contact layer 105.
A post 751 on the left side is a dummy post having a p-side electrode 715 electrically connected to the p-type semiconductor multilayer mirror 111 of the laser device. .

Reference numeral 701 denotes an Si substrate, 703 and 705
Is a wiring connected to the p-side and n-side electrodes 715 and 417, respectively, and 707 is a solder bump made of AuSn.
Further, a light receiving element 709 having a pin structure is integrated at a position where light from the surface side of the laser element can be received.

In this embodiment, the GaAs substrate 101
Since light is removed, light of 780 nm can be extracted from the back side, and further, by providing the light receiving element 709 on the front side, a surface emitting laser device having a light quantity monitor can be realized.

(Sixth Embodiment) A sixth embodiment of the surface emitting laser device according to the present invention will be described with reference to FIG. FIG.
1 is a sectional view of a surface emitting laser device according to the present embodiment. Although the above plurality of embodiments are surface emitting laser devices provided with both p and n electrodes on the surface side, the present invention provides a surface emitting laser device provided with p electrodes and n electrodes on both sides of the substrate. It can also be configured. The sixth embodiment is such an example.

In this embodiment, as shown in FIG.
The n-Al _{0 . 9} Ga _0.1 As
/ N-Al _0.3 Ga _{0.7 As} 39.5-period n-type semiconductor multilayer mirror layer 803, active layer 807, Al
A p-type current confinement layer 809 including a containing semiconductor layer (an insulating layer 810 is formed by oxidizing the current confinement layer 809), a p-type contact layer 811 and p-Al _0.3 G
a _0.7 As / p-Al _0.9 Ga _{0.1 As} 29.5
Periodic p-type semiconductor multilayer mirror layer 813, 50 °
Each layer of the p-type contact layer 814 made of GaAs is laminated to form a resonator structure.

The manufacturing method is almost the same as in the second embodiment. However, in the sixth embodiment, the n-GaAs substrate 80
An n-side electrode 817 made of AuGe / Au is formed on the back surface of the first substrate 1, and a p-side electrode 815 made of Cr / Au is formed so as to cover the uppermost portion of the inner post and the p-type contact layer 811. I have.

Active layer 807, p-type current confinement layer 809, p
The layer structure of the contact layer 811 is the same as that of the active layer 207, the p-type current confinement layer 209, and the p-type contact layer 211 in the second embodiment.

By adopting such a configuration, except for the effect of providing both the p and n electrodes on the surface side, the first
The same effect as that of the embodiment can be obtained.

[0075]

As described above, according to the present invention,
Particularly, in a wavelength band where GaAs is not transparent, such as 780 nm and 830 nm, a surface emitting laser device having a small element resistance, a low threshold current, and capable of removing a substrate and excellent in integration with other devices, and The manufacturing method can be provided. Further, a surface emitting laser device having both p and n electrodes on the surface side can be easily realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a layer configuration of a first embodiment according to the present invention and a relationship between each layer and an electric field intensity distribution.

FIG. 2 is a diagram illustrating a manufacturing process of the first embodiment.

FIG. 3 is a sectional view showing a second embodiment according to the present invention.

FIG. 4 illustrates a manufacturing process of a second embodiment.

FIG. 5 is a sectional view showing a third embodiment according to the present invention.

FIG. 6 is a sectional view showing a fourth embodiment according to the present invention.

FIG. 7 is a sectional view showing a fifth embodiment according to the present invention.

FIG. 8 is a sectional view showing a sixth embodiment according to the present invention.

FIG. 9 is a diagram showing a first conventional example.

FIG. 10 is a diagram showing a second conventional example.

[Explanation of symbols]

101, 201, 801 GaAs substrate 103, 203, 803 n-type semiconductor multilayer mirror 105, 205 n-type contact layer 107, 207, 807 active layer 109, 209, 809 p-type current confinement layer 110, 210, 810 insulating layer 111 , 213, 813 p-type semiconductor multilayer mirror 112, 211, 214, 811 p-type contact layer 113, 215, 415, 416, 715, 815
p-side electrode 115, 217, 417, 817 n-side electrode 411 SiN _x insulating film 450, 650 dummy post 601 AlN substrate 603, 605, 703, 705 wiring 607, 707 solder bump 701 Si substrate 709 light receiving element

Claims (27)

[Claims] 1. A method according to claim 1, wherein at least a first polarity of a first polarity is provided on the substrate.
A semiconductor multilayer mirror layer, a first polarity contact layer,
A resonator structure in which an active layer and a second semiconductor multilayer mirror layer having a second polarity are stacked in this order or in reverse order, and the contact layer having the first polarity has at least one layer. The semiconductor device has a structure in which semiconductor layers having a high carrier concentration and at least one semiconductor layer having a low carrier concentration are alternately laminated, and the first polarity contact layer and the first pole side electrode are electrically connected to each other. A surface emitting laser device which is connected. 2. A multi-layer semiconductor layer having a first polarity, a first multi-layer mirror having a first polarity, a contact layer having a first polarity, an active layer, and a second multi-layer mirror having a second polarity. , Having a resonator structure formed by laminating each layer in this order,
2. The surface emitting laser device according to claim 1, further comprising a p-side and an n-side electrode on the front side of the substrate. 3. At least a first semiconductor multilayer mirror layer of a first polarity, a contact layer of a first polarity, an active layer, and a second semiconductor multilayer mirror layer of a second polarity on the substrate. , And a resonator structure formed by laminating layers in reverse order, and a first pole-side electrode and a second pole-side electrode are provided on the front side and the back side of the substrate, respectively. The surface emitting laser device according to claim 1, wherein 4. The composition of each layer constituting the first polarity contact layer so that the semiconductor layer having a high carrier concentration is located at a node of a standing wave of an electric field existing in a resonator. 4. The surface emitting laser device according to claim 1, wherein a film thickness is set. 5. The semiconductor device according to claim 1, wherein the first polarity contact layer has a stacked structure of AlGaAs having different Al compositions, and a semiconductor layer having a high carrier concentration has a smaller Al composition than a semiconductor layer having a low carrier concentration. Claims 1 to 4
The surface emitting laser device according to any one of the above. 6. A current confinement structure formed by oxidizing an AlGaAs layer including at least a semiconductor layer having an Al composition of 0.9 or more is provided in the vicinity of an active layer. The surface emitting laser device according to any one of the above. 7. A second contact layer having a second polarity and having a structure in which at least one semiconductor layer having a high carrier concentration and at least one semiconductor layer having a low carrier concentration are alternately stacked, the active layer and the second contact layer having a second polarity are formed. 7. The surface emitting laser device according to claim 1, wherein the surface emitting laser device is inserted between the second semiconductor multilayer mirror layer and the second semiconductor multilayer mirror layer. 8. The surface emitting laser device according to claim 7, wherein the contact layer having the second polarity and the electrode on the second pole side are electrically connected. 9. The composition of each layer constituting the contact layer having the second polarity, such that the semiconductor layer having a high carrier concentration is located at a node of a standing wave of an electric field existing in the resonator; 9. The surface emitting laser device according to claim 7, wherein a film thickness is set. 10. The contact layer of the second polarity is formed of Al.
10. The surface emitting laser according to claim 7, wherein the semiconductor layer having a high carrier concentration has a smaller Al composition than a semiconductor layer having a low carrier concentration. apparatus. 11. An electrode on a first pole side or a second pole side,
A side surface of the first or second semiconductor multilayer mirror which is electrically connected to the first or second semiconductor multilayer mirror and electrically connected to the first or second polarity contact layer; The surface emitting laser device according to claim 1, wherein the surface emitting laser device is formed so as to go around. 12. At least the active layer and the second or first
12. A post having a laminated structure including the semiconductor multi-layer mirror layer of claim 1.
The surface emitting laser device according to any one of the above. 13. An electrode on a second or first pole side electrically connected to a second or first semiconductor multilayer mirror on the uppermost surface of the first post, having at least two of the post shapes. Is formed, and on the uppermost surface of the second post, a first or second pole-side electrode electrically connected to a contact layer of the first or second polarity has a side surface of the second post. 13. The surface emitting laser device according to claim 12, wherein the surface emitting laser device is formed in a round shape. 14. The surface emitting laser device according to claim 13, wherein said two or more post shapes have the same laminated structure. 15. The resonator structure on the substrate is bonded to another substrate provided with electric wiring at a position opposite to the electrodes of the first polarity and the second polarity, with the front surface side as an adhesive surface. 15. The surface according to claim 1, wherein the first polarity electrode, the second polarity electrode and the electric wiring are electrically connected. Light emitting laser device. 16. The surface emitting laser device according to claim 15, wherein the resonator structure on the substrate and another substrate are electrically and mechanically bonded by solder bumps. 17. The surface emitting laser device according to claim 15, wherein the substrate is removed from the resonator structure on the substrate except for a semiconductor layer forming the resonator. 18. The surface emitting laser device according to claim 15, wherein said another substrate is made of AlN. 19. The method according to claim 19, wherein said another substrate is a Si substrate.
18. The substrate according to claim 15, wherein an electric wiring and a light receiving device are formed on the substrate, and the light receiving device is arranged at a position capable of receiving light emitted from the surface side of the resonator.
The surface emitting laser device according to any one of the above. 20. The method according to claim 19, wherein said another substrate is a Si substrate.
18. The surface emitting laser device according to claim 15, wherein an electric wiring and an electronic circuit are integrated on the substrate. 21. The surface emitting laser device according to claim 1, wherein the oscillation wavelength is in a wavelength band absorbed by GaAs. 22. The method for manufacturing a surface emitting laser device according to claim 1, wherein a first semiconductor multilayer mirror layer having a first polarity is formed on a substrate. Forming a resonator structure by stacking and growing layers of a contact layer, an active layer, and a second semiconductor multilayer mirror layer of a second polarity in this order or in reverse order, and exposing the contact layer of the first polarity. Etching the active layer, the second or first semiconductor multilayer mirror layer until a post shape is formed, and forming on the first polarity contact layer or the first polarity contact layer and the first semiconductor Forming a first pole-side electrode on the multilayer mirror layer; and forming a second pole-side electrode on the second semiconductor multilayer mirror or on the back surface of the substrate. Of manufacturing a surface emitting laser device. 23. The method according to claim 22, wherein the step of obtaining ohmic contact with the first pole side electrode and the step of obtaining ohmic contact with the second pole side electrode are performed simultaneously or separately. A method for manufacturing a surface emitting laser device. 24. A step of growing an AlGaAs layer including a semiconductor layer having at least an Al composition of 0.9 or more during semiconductor growth, and a step of selectively oxidizing the AlGaAs layer from a side surface to form a current confinement structure. The method for manufacturing a surface emitting laser device according to claim 22 or 23, wherein 25. A step of forming at least two post shapes including at least an active layer and a second or first semiconductor multilayer mirror layer, and forming a second post on the top surface of the first post.
Alternatively, a step of forming a second or first pole side electrode electrically connected to the first semiconductor multilayer mirror, and forming a first or second polarity contact layer on the uppermost surface of the second post. 25. The surface emitting laser according to claim 22, further comprising a step of forming the first or second pole side electrode that is electrically connected so as to extend around the side surface of the second post. Device manufacturing method. 26. The surface emitting laser device according to claim 22, further comprising a step of bonding the resonator structure on the substrate to another substrate provided with electric wiring, with a front surface of the resonator structure as a bonding surface. Manufacturing method. 27. The surface emitting laser device according to claim 26, further comprising the step of removing the substrate after bonding, leaving the semiconductor layer forming the resonator out of the resonator structure on the substrate. Production method.