JPH05198896A - Semiconductor element - Google Patents

Abstract

PURPOSE:To obtain a wavelength control type semiconductor laser excellent in characteristics wherein the deqree of freedom of ease structure of formation is high. CONSTITUTION:On a semiconductor substrate 101 having a periodical uneven structure 106, an optical waveguide region or a light emitting region is flatly epitaxially grown, in the manner in which gain distribution and/or refractive index distribution reflects the uneven structure 106 and periodically distributes, thereby forming a wavelength control type semiconductor laser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical or electronic device, and more particularly to a wavelength control type semiconductor laser which can be integrated and is used in an information processing device such as an optical memory, an optical computer, optical measurement, etc. The present invention relates to a high-speed electronic device and a low power consumption device used in a capacity computer, a neuro computer and the like.

[0002]

2. Description of the Related Art In recent years, a distributed Bragg reflector focusing on wavelength selectivity has been developed.
ter, hereinafter DBR) laser and distributed feedback type (Dist)
A ribbed fed back (DFB) laser has been developed, but this type of laser has excellent characteristics as a single longitudinal mode laser.

The semiconductor laser shown in FIG. 11 is AlGaA.
A distributed feedback DFB semiconductor laser, which is a typical example of the s-series system, is provided along the optical guide layer 1104.
7 is incorporated. In addition, in FIG.
The structural example of a P-type DFB laser is shown. In the figure, 1001 is I
nP substrate, 1002 is a light guide layer, 1003 is an active layer,
1004 is a cladding layer, 1005 is a contact layer, 10
Reference numeral 06 denotes a diffraction grating, respectively.

The parallel reflection wavelength λ ₀ for parallel incidence by the diffraction grating is represented by λ ₀ = 2NeffΛ / m. Here, Neff is the equivalent refractive index in the diffraction grating region, Λ is the diffraction grating period, and m is the order of the diffraction grating.
DBR lasers and DFB lasers realize single longitudinal mode oscillation by utilizing this wavelength selectivity.

Furthermore, in recent years, with the aim of improving the functionality and performance of optical devices and electronic devices, a semiconductor ultra-thin film structure has been adopted, the quantum mechanical wave nature of electrons has been revealed, and various quantum effects have been applied. Research on optical devices and electronic devices is underway.

For example, a quantum well structure laser can be mentioned as an example (FIG. 11). In such a quantum well structure laser, electrons and holes are confined in the quantum well layer 1201 in the layer thickness direction and quantized by the confinement layer 1202, so that the threshold current density is small and the temperature characteristic is excellent. It has characteristics. (El as reference
electronics Letters 1982 18
No. 1095)

[0007]

Problems to be Solved by the Invention AlGa shown in FIG.
In the As-based DFB laser, the clad layer 1102, the active layer 1103, and the optical guide layer 1104 are sequentially grown on the GaAs substrate 1101 by the first epitaxial growth,
After forming the diffraction grating 1107 on the surface of the light guide layer 1104, the cladding layer 1 is formed by second epitaxial growth.
105 and the contact layer 1106 must be sequentially grown. The above structure requires at least two epitaxial growth processes. Further, there is a problem that non-radiative recombination centers are generated at the regrowth interface on the diffraction grating, resulting in a decrease in luminous efficiency and a decrease in reliability.

On the other hand, the InP-based DFB laser shown in FIG. 9 has no absorption loss of oscillation light in the substrate, unlike the AlGaAs-based DFB laser. Therefore, the diffraction grating 1006 is formed on the substrate 1001 and then epitaxial growth is performed once. Thus, the light guide layer 1002, the active layer 1003, the cladding layer 1004, and the contact layer 1005 can be sequentially formed. However, since the optical electric field intensity must be distributed on the diffraction grating 1006 formed on the substrate 1001, the waveguide region including the active layer cannot be kept away from the diffraction grating 1006. Therefore, the problems of reduced emission efficiency and reduced reliability due to non-radiative recombination centers occurring at the regrown interface on the diffraction grating cannot be avoided. Also, the degree of freedom for improving the optical characteristics is reduced.

The present invention has been made in order to solve such a problem, and it is possible to obtain a high-quality laser beam with low power consumption and no mode separation or mode hopping. Moreover, the manufacturing process is simple and the optical characteristics are excellent. An object of the present invention is to provide a semiconductor device such as a wavelength-controlled semiconductor laser which is excellent and can be integrated with a light control device or the like.

Further, in the quantum well laser shown in FIG. 11, only the quantum well is quantized in the direction perpendicular to the layer, and the quantum well is not quantized in the direction parallel to the quantum well. There is a point that the improvement of
A laser utilizing the quantum wire effect by the curved active waveguide as shown in FIG. 2 and the quantum box effect as shown in FIG. 13 has been proposed. (Patent publication No. 212084, 1986, No. 212085, 1986)
Issue, Journal of Crystal Gr
out 104 (1990) 766-772) However, these structures have one or a multi-layer active layer which is a gain region, and the layer thickness of this active layer is so thin that the quantum effect appears, and By having a undulation with a period that is so short that a quantum effect appears in the plane direction, electrons and holes are also confined in the undulation direction, and the quantum effect is adopted to achieve high performance. In order to confine holes also in the direction of undulation, it is necessary to grow and form an active region within a short distance from the formed uneven substrate, which limits the degree of freedom of the device structure.
Furthermore, it is very difficult to avoid problems such as non-radiative recombination that occur at the interface with the uneven substrate.

[0011]

The present invention comprises a waveguiding region including an active layer, an electric field intensity distribution of light or electrons guided by the waveguiding region, and an uneven portion where the distribution does not reach. The present invention provides a semiconductor device in which the uneven distribution gives a gain distribution and / or a refractive index distribution to the waveguide region.

Further, the present invention provides a semiconductor device in which the irregularities are periodically formed.

The principle of the semiconductor device according to the present invention will be described with reference to the conceptual diagram of FIG. 1 by taking a semiconductor laser as an example.
In the figure, reference numeral 101 denotes a semiconductor substrate on which a periodic uneven portion 106 is formed. The first clad layer 102, the active layer 103, the second clad layer 104, and the contact layer 105 are sequentially laminated on the periodic concavo-convex portion 106 formed on the semiconductor substrate 101 by one-time epitaxial growth to form an optical waveguide region. And forming a laser structure including a light emitting region.

The waveguide region formed by the epitaxial growth is formed substantially flat, and due to the difference in the growth mechanism on the uneven portion formed on the surface of the semiconductor substrate,
A gain distribution and / or a refractive index refractive index distribution is formed in the waveguide region, and the distribution changes in accordance with the period of the uneven portion formed on the semiconductor substrate surface.

Further, in this semiconductor laser, even if the optical field intensity distribution does not exist in the periodic unevenness formed on the surface of the semiconductor substrate, the gain distribution and / or the refractive index distribution formed in the waveguide region Light is returned.

Moreover, since the gain distribution or the refractive index distribution is formed in the optical waveguide direction by using the quantum effect structure in the waveguiding region, it is possible to form a quantum wire and a quantum box, which is greatly effective in improving the semiconductor laser characteristics. Demonstrate.

[0017]

In the present invention, it is possible to form a wavelength control type semiconductor laser structure by a single epitaxial growth, and since the optical waveguide region and the light emitting region are flat, the optical characteristics are improved. It is also effective in improving the light wave coupling efficiency. Furthermore, since there is no need for a distribution of the optical electric field strength at the regrowth interface on the uneven portion of the substrate, the degree of freedom in matching with other devices in the layer direction due to monolithicization is improved, and it is also effective in improving reliability. There is.

Further, by adopting a quantum effect structure in the waveguiding region, it is easy to further add a gain distribution or a refractive index distribution in the waveguiding direction, which makes it difficult to fabricate the quantum wire device and the quantum box. The device can be manufactured, and an optical device and an electronic device with ultra-high speed and ultra-low power consumption can be realized.

[0019]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto.

2A to 2C are a schematic view and a characteristic view of the first embodiment of the present invention. In FIG. 2A, 201 is n-
This is a GaAs substrate, and a diffraction grating 206 having a predetermined period Λ (2000 to 2500Å) is formed on one main surface of the substrate 201. This can be formed by the known two-beam interference exposure method or electron beam exposure method and etching technology. On the n-GaAs substrate 201 on which the diffraction grating 206 is formed, n-type AlGaA is formed by using the low pressure MOCVD method.
s (Al composition ratio X = 0.5)
μm, AlGaAs (Al composition ratio X = 0.13), the active layer 203 is 0.1 μm, and p-type AlGaAs (composition ratio X =
0.5) 0.5 μm clad layer 204, p-type GaAs
The contact layer 205 is sequentially grown to 1.0 μm. At this time, the growth temperature is 600 to 750 ° C., the V / III ratio is 60 to
The growth at 120 makes it possible to grow the active layer 203 flat.

After this epitaxial growth step, electrodes are formed on the epitaxial growth layer and on the back surface of the substrate 201 (not shown) to fabricate a 10 μm electrode stripe structure laser device. Figure 2 shows the typical device characteristics.
Shown in (b) and (c). FIG. 2B shows current-light output characteristics. The threshold current Ith to 110 mA, the drive current Iop to 140 mA at 10 mW, and the characteristics equivalent to those of the conventional Fabry-Perot type laser show no optical absorption loss. Therefore, the optical field intensity distribution on the n-GaAs substrate 201 is as designed. It turns out that does not exist. Also 10mW APC
The oscillation wavelength temperature dependency during pulse driving is shown in FIG. Dynamic single longitudinal mode temperature range ΔT ~ 80 ° C and good D
The FB mode characteristic is shown.

From the above results, the optical electric field intensity distribution is n-type Ga.
It shows the DFB mode operation even though it does not exist on the diffraction grating 206 formed on the As substrate 201.
This means that the active layer 203 and the optical waveguide region (202,
It is shown that the gain distribution or the refractive index distribution in (203, 204) corresponds to the period of the diffraction grating 206 formed on the n-type GaAs substrate 201.

Influenced by the plane orientation dependence of the growth rate on the diffraction grating 206 by the epitaxial growth method, stress strain corresponding to the period of the diffraction grating 206 is formed in the flat active layer and the optical waveguide region. Therefore, the gain distribution is formed equivalently. This stress strain becomes more remarkable as the difference in the mixed crystal ratio between the growth layers and the growth temperature increase.

At the same time, the amount of impurity concentration taken into the growth layer also changes due to the difference in the growth rate depending on the plane orientation forming the diffraction grating 206, thereby forming an equivalent gain distribution. It becomes possible. This can be done by making the growth rate different according to the growth temperature, the growth pressure, and the flow rate of the source gas.

FIG. 3 is a schematic diagram of the second embodiment of the present invention. FIG. 3 is a central longitudinal drawing along a plane parallel to the traveling direction of light of an AlGaAs 830 nm band semiconductor laser. In this embodiment, n-type Al is formed on the n-type GaAs substrate 301.
_{0 · 45} Ga _{0 · 55} As the diffraction grating inscription layer 302 are stacked. The n-type _{Al 0 · 45 Ga 0 · 55} As the diffraction grating embossed layer 30
A diffraction grating 307 having a predetermined period Λ (2000 to 2500Å) is formed on the two main surfaces. This can be formed by the known two-beam interference exposure method or electron beam exposure method and etching technology.

N-type Al on which the diffraction grating 307 is formed
_{0 · 45} Ga _{0 · 55} vacuum on As the diffraction grating inscription layer 302 MOC
Using the VD method, n-type Al ₀ .45 Ga _{0 .55} As clad layer 303, Al _{0 .05} Ga _{0 .95} As active layer 304, P-type Al
_{0 · 45} Ga _{0 · 55} As cladding layer 305 are successively grown a p-type GaAs contact layer 306.

At this time, the active layer 304 can be grown flat by controlling the growth temperature, the V / III ratio, and the growth layer thickness.

The difference between this embodiment and the first embodiment is that the diffraction grating engraving layer 302 and the n-type cladding layer 303 have the same Al mixed crystal ratio, so that the modulation of the refractive index in the diffraction grating 307 does not occur. Not happening. However, a gain distribution or a refractive index distribution corresponding to the period of the diffraction grating 307 is formed in the flat active layer and the optical waveguide region by the same operation as in the first embodiment, and the guided laser light is obtained. Despite the absence of geometrical diffraction grating, good D
FB mode operation becomes possible.

FIG. 4 is a schematic diagram of the third embodiment of the present invention. FIG. 4 is a longitudinal center view of an InP-based 1.3 μm band semiconductor laser along a plane parallel to the light traveling direction.

In the figure, 401 is an InP substrate, 402 is a diffraction grating engraving layer, 403 is a first cladding layer, 404 is an active layer,
405 is a second cladding layer, 406 is a contact layer, 40
Reference numerals 7 respectively indicate diffraction gratings.

The difference from the conventional structure of the InP DFB laser shown in FIG. 9 is that the active layer 404 and the diffraction grating 4 are provided.
Even if the distance from the antenna is greater than or equal to the guide wavelength (d = λ / n, where λ is the oscillation wavelength and n is the effective refractive index) (> 0.4 μm), the same effect as that of the first embodiment is obtained, and good results are obtained. DFB
The mode operation is enabled, and the electric field intensity distribution of the light guided to the waveguiding region including the active layer 404 does not exist at the regrown interface on the diffraction grating 407. Problems such as reliability can be avoided.

FIG. 5 is a schematic view of the fourth embodiment of the present invention. FIG. 5 is a central longitudinal view of a ZnCdSSe-based 460 nm band semiconductor laser along a plane parallel to the light traveling direction.

In this embodiment, a diffraction grating 510 having a predetermined period Λ is formed on the main surface of the n-type GaAs substrate 501. The period Λ of the diffraction grating 510 is 800-in the first-order diffraction grating.
1000 Å, 1600 to 2000 Å for 2nd order diffraction grating
This can be formed by the well-known electron beam exposure method and etching technology. This diffraction grating 51
MOCVD on the n-type GaAs substrate 501 on which 0 is formed
N-ZnSe buffer layer 502, ZnSSe
Cladding layer 503 (2.5 μm), ZnSeSCH layer 5
04 (0.5 μm), ZnCdSe active layer 506 (10
nm), ZnSe-SCH layer 507 (0.5 μm), Z
nSSe clad layer 508 (1.5 μm) and ZnSe
A contact layer 509 (0.1 μm) is sequentially grown.

Also in this embodiment, the active layer 506 and the optical waveguide region are flattened by controlling the MOCVD growth conditions by the same operation as in the first embodiment, and the diffraction grating 51 is used.
A gain distribution or a refractive index distribution is formed corresponding to a cycle of 0, and it becomes possible to easily obtain a DFB mode operation even in a ZnCdSSe system.

FIG. 6 is a schematic view of the fifth embodiment of the present invention. FIG. 6 is a central longitudinal drawing along a plane perpendicular to the traveling direction of light of an AlGaAs semiconductor quantum wire laser.

In FIG. 6, reference numeral 601 denotes an n-GaAs substrate, which has a predetermined period (500 to 10) on the main surface of the substrate 601.
A diffraction grating 606 of 00Å) is formed. This can be formed by a well-known technique such as an electron beam exposure method and an etching technique. N-Ga on which the diffraction grating 606 is formed
Low pressure MOCVD is performed on the As substrate 601 as in the above-described embodiment.
N-type AlGaAs cladding layer 602, Al
GaAs GRIN SCH SQW layer structure 603, p
Type AlGaAs clad layer 604 and p type GaAs contact layer 605 are sequentially formed.

Here, the difference from the above embodiment is that in this embodiment, GRIN SCH SQ is formed in the active region and the optical waveguide region.
The W layer structure 603 is provided, and the period of the diffraction grating 606 formed on the main surface of the substrate 601 is reduced to such an extent that a quantum effect appears.

With such a structure, the same effects as those of the previous embodiment can be obtained, and in addition to that, the following effects can be obtained. A gain distribution or a refractive index distribution can be given to the active region corresponding to the concave-convex period of the diffraction grating 606, and a one-dimensional quantum effect semiconductor laser can be formed. As a result, a semiconductor laser that consumes very little power and can respond at high speed can be obtained.

FIG. 7 is a schematic view of the sixth embodiment of the present invention. The difference between this embodiment and the fifth embodiment is that the periodic concavo-convex structure 706 formed on the n-type GaAs substrate 701.
A two-dimensional concavo-convex structure is used for the structure, the period is set to about 0.1 μm at which electrons can be confined, and the 780 nm band DFB is used.
The first-order diffraction grating period Λ is 0.1 μm, which can also operate as a laser diffraction grating. This periodic uneven structure can be formed by an electron beam exposure method. In addition, the first-order diffraction grating period Λ ~ 0.1 μm that enables the DFB laser operation is required for the waveguide direction of the light wave, but the electron confinement effect is more strongly exerted in the direction perpendicular to the waveguide direction of the light wave. Needless to say, it is effective to set the thickness to 0.1 μm or less.

In addition, after forming a periodic concavo-convex structure mask by the electron beam exposure method, in order to strongly reflect the influence of the periodicity of the concavo-convex structure on the active region, a typical method is reactive ion etching (RIE) using chlorine gas. It is effective to form a periodic concavo-convex structure having a large aspect ratio by using the dry etching technique described above.

The active region 7 is formed on the periodic uneven structure.
03 and the optical waveguide regions (702, 703, 704) are epitaxially grown, it is possible to form a gain distribution in the two-dimensional direction in the active region 703 corresponding to the two-dimensional periodic concavo-convex structure. From this, it is possible to obtain a zero-dimensional quantum box effect in combination with the MQW structure (703) in the layer thickness direction, and it becomes possible to fabricate an ultra-low power consumption, ultrafast DFB laser. In addition, in FIG.
Reference numeral 05 is a contact layer, and 706 is a diffraction grating.

As described above, the periodic concavo-convex structure is formed on the semiconductor substrate, and the optical waveguide region or the light emitting region is flatly grown on the periodic concavo-convex structure by one epitaxial growth. By periodically distributing the gain distribution and / or the refractive index distribution in the waveguide region and the light emitting region while reflecting the concavo-convex structure, it is possible to obtain a wavelength controlled semiconductor laser having excellent characteristics. In addition, since the light emitting region or the optical waveguide region is flat, the next generation O
It is easy to obtain high coupling efficiency with other devices for monolithicization such as EIC.

Further, a periodic uneven structure is formed on the substrate,
Moreover, since the optical electric field intensity is not distributed on the surface of the periodic uneven structure on the substrate, as means for forming the periodic uneven structure,
It is also possible to apply a dry processing process including the problem of damage.

Further, since the periodic gain distribution or the refractive index distribution is formed in the entire optical waveguide region and the light emitting region, it is also a great effect to enable the dynamic single longitudinal mode oscillation characteristic with very strong coupling efficiency. .. Moreover, it is possible to easily select the magnitude of the coupling efficiency by designing the growth conditions or the structure.

As described above, a wavelength controlled semiconductor laser capable of oscillating a dynamic single longitudinal mode, which can be a key device of the next-generation OEIC, can be easily obtained with a high degree of freedom in design and excellent characteristics can be obtained. There is an effect that is.

FIG. 8 is a schematic view of the seventh embodiment of the present invention. FIG. 8 is a structural diagram of a quantum wire transistor. Figure 8
801 is a GaAs substrate, and a period (<300Å) below the de Broglie wavelength of electrons is present on the main surface of the substrate 801.
Diffraction grating 808 is formed. This can be formed by a well-known technique such as an electron beam exposure method and an etching technique. GaAs substrate 80 having this diffraction grating 808 formed
1 on top of the GaA layer by the low pressure MOCVD method as in Example 1.
s-channel layer 802, quantum well structure AlGaAs spacer layer 803, AlGaAs carrier doping layer 80
4. A GaAs contact layer 809 is sequentially grown, and a source region 807, a gate region 806 and a drain region 805 are formed by ion diffusion. After this epitaxial growth, electrodes are formed in the respective regions to fabricate a quantum wire transistor device.

Similar to the above-described embodiment, since the band modulation is performed in the direction perpendicular to the moving direction of electrons corresponding to the period of the diffraction grating 808, when the gate voltage is changed by the quantum wire effect, the location where the electrons are localized. Changes, and the electron mobility can be changed. In this way, it becomes possible to fabricate a quantum wire transistor that can operate at low voltage and at high speed.

In the above embodiment of the present invention, AlGaAs
Although the description has been made by using the DFB laser of the system, the present invention is not limited to this, and InP system, InGaAlP are used.
Other group III-V, such as a system, or group II-VI, I-III
Similar effects can be obtained for other groups such as -V group.
Not only the DFB laser but also the DBR laser, the DR laser, the wavelength selection filter element and the like can be applied. Further, it is needless to say that the uneven portion is not limited to the periodic shape and can be applied not only to the optical device but also to the electronic device.

[0049]

As described above, according to the present invention, the characteristics of the substrate such as the band gap are not dependent, the damage of the unevenness processing does not reach the waveguide region, and the re-growth interface level can be escaped. Becomes

Further, by making the uneven portion periodic,
Single longitudinal mode oscillation can be easily obtained, electrons of single energy can be made to travel, and high speed operation can be achieved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the principle of the present invention.

FIG. 2 is a schematic view and a characteristic diagram showing a semiconductor laser device according to a first embodiment of the present invention.

FIG. 3 is a schematic diagram showing a semiconductor laser device according to a second embodiment of the present invention.

FIG. 4 is a schematic view showing a semiconductor laser device according to a third embodiment of the present invention.

FIG. 5 is a schematic diagram showing a semiconductor laser device according to a fourth embodiment of the present invention.

FIG. 6 is a schematic view showing a semiconductor laser device according to a fifth embodiment of the present invention.

FIG. 7 is a schematic view showing a semiconductor laser device according to a sixth embodiment of the present invention.

FIG. 8 is a schematic view showing a semiconductor laser device according to a seventh embodiment of the present invention.

FIG. 9 is a schematic view showing a conventional semiconductor laser device.

FIG. 10 is a schematic view showing a conventional semiconductor laser device.

FIG. 11 is a schematic view showing a conventional semiconductor laser device.

FIG. 12 is a schematic view showing a conventional semiconductor laser device.

FIG. 13 is a schematic view showing a conventional semiconductor laser device.

[Explanation of symbols]

10 substrate 11 buffer layer 12 n-type clad layer 13 first guide layer 14 active layer 15 second guide layer 16 p-type clad layer 17 cap layer 18 p-electrode 19 n-electrode 101 semiconductor substrate 102 first clad layer 103 light-emitting region 104th 2 clad layer 105 contact layer 106 periodic uneven structure 201, 301, 401, 501 601 701 8
01n type GaAs substrate 202, 303, 403, 602 702n type AlGa
As clad layer 204, 305, 405, 604 704 p-type AlGa
As clad layer 205, 306, 406, 605 p-type GaAs contact layer 203 p-type AlGaA
s Active layer 603 GRIN ・ SC
H · SQW active layer 703 MQW active layer 206, 307 Periodic uneven structure Second-order diffraction grating Λ to 2200Å 510 Periodic uneven structure First-order diffraction grating Λ to 1100Å 706 Two-dimensional periodic uneven structure ~ Λ to 1000Å 503 ZnSSe cladding layer 506 ZnCdSe active layer 508 ZnSSe clad layer 509 ZnSe contact layer 801 GaAs substrate 802 GaAs channel layer 803 quantum well structure AlGaAs spacer layer 804 AlGaAs carrier doping layer 805 drain region 806 gate 807 source region 808 diffraction grating (period <300Å)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Haruhisa Takiguchi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation

Claims (5)

[Claims] 1. A waveguide region including an active layer, an electric field intensity distribution of light or electrons guided by the waveguide region, and a concavo-convex portion where the distribution does not reach. A semiconductor device characterized by being provided with a gain distribution and / or a refractive index distribution in a wave region. 2. The semiconductor device according to claim 1, wherein the uneven portion is formed periodically. 3. The uneven portion is separated from the waveguide region including the active layer by a guide wavelength or more.
The semiconductor device described. 4. An active layer, which is a gain region, is provided on a semiconductor substrate having a periodic concavo-convex portion formed in a light or electron guiding direction, and the layer thickness of the active layer is a quantum effect. In a semiconductor element formed so thin that the gain appears in the gain region such that the gain region is flat and the unevenness distribution formed on the semiconductor substrate causes a quantum effect to appear in one direction in the plane direction of the active layer. The semiconductor device according to claim 1, wherein the semiconductor device is provided with a distribution and / or a refractive index distribution. 5. An active layer, which is a gain region, is provided on a semiconductor substrate having a periodic uneven portion formed in the direction in which light or electrons are guided, and the layer thickness of the active layer has a quantum effect. And the gain distribution is flat in the gain region and the unevenness distribution formed on the semiconductor substrate has a gain distribution and / or a gain distribution in the gain region such that quantum effects appear in at least two different plane directions of the active layer. The semiconductor device according to claim 1, wherein the semiconductor device is provided with a refractive index distribution.