JP4652712B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device having a quantum nanostructure.

  In recent years, with the spread of various multimedia including the Internet, an increase in data traffic has become a problem. Therefore, in order to solve the problem, WDM (wavelength multiplex transmission) systems have made remarkable development and become widespread.

  In the WDM system, a plurality of optical signals are transmitted on different wavelengths, respectively, thereby realizing a large capacity transmission that is 100 times as large as that of a conventional fiber. In particular, the existing WDM system enables broadband and long-distance transmission by using an optical fiber amplifier such as an erbium-doped fiber amplifier (hereinafter referred to as EDFA) or a Raman amplifier.

  Here, the EDFA transmits these light by passing light having a wavelength of 1480 nm or light having a wavelength of 1550 nm, which is a transmission signal when excited by an excitation laser having a wavelength of 980 nm, through an optical fiber to which an element called erbium is added. Is an optical fiber amplifier that applies the principle that is amplified in the optical fiber.

  The Raman amplifier is an optical fiber amplifier that uses a normal transmission line fiber as a gain medium without using a special optical fiber such as an erbium-doped fiber like an EDFA, and is based on the assumption that a conventional EDFA is used. Compared to a WDM system, it has a feature that a transmission band having a wide band and a flat gain can be realized.

In order to improve the stability of the WDM system and reduce the number of relays, the optical fiber amplifier described above requires a high-power semiconductor pumping light source (pumping laser) that operates stably in the horizontal single transverse mode. .
On the other hand, in a signal light source of a WDM system, a semiconductor signal light source (signal laser) capable of single-mode oscillation capable of high-speed modulation with a narrow line width is required for large capacity and long distance transmission.
Thus, in the current optical fiber communication system, the semiconductor laser is an indispensable device. In particular, a buried hetero (BH) type semiconductor laser having a quantum well structure, preferably a multiple quantum well structure (MQW structure: Multi-Quantum Well structure) composed of a plurality of quantum wells and barrier layers as an active layer is stable. It is effective in realizing a horizontal single mode. In fact, a semiconductor laser module packaged with a semiconductor laser having these structures is used as a semiconductor pump light source for an optical fiber amplifier or a semiconductor signal light source for a WDM system. Yes.

  As a technique for realizing high output of a semiconductor laser, it is known to form an active layer with a multiple quantum well (MQW) structure, particularly a strained MQW structure. The MQW structure is realized by alternately heterojunction of a well layer and a barrier layer made of a semiconductor material, and in each heterojunction, the barrier layer has a wider band gap energy than the well layer. Yes. Further, the strained MQW structure is a structure in which the lattice constant of the semiconductor material of the well layer is different from the lattice constant of the semiconductor substrate, and it is known that higher performance can be achieved.

  Here, in order to improve characteristics such as significantly reducing the oscillation threshold and improving the temperature characteristics of the laser oscillation characteristics, the quantum well active layer uses quantum nanostructures of nano-order two-dimensional or three-dimensional structures such as quantum wires and quantum dot structures. Has been announced to be effective. This is due to the fact that carriers such as electrons or holes are confined in a two-dimensional or three-dimensional potential, thereby producing a quantum size effect, and the state density is localized or sharpened to a specific discrete order. In recent years, a method of forming a quantum dot structure using a SK (Stranski-Krastanow) mode, that is, a self-organization phenomenon during crystal growth using the strain energy of the crystal has been actively studied. . (See Non-Patent Document 1)

“Self-organization of semiconductor nanostructures”, Masashi Ozeki, Yuichiro Shimizu Applied Physics Vol. 72, No. 10 (2003)

  Non-Patent Document 1 discloses a process of forming quantum dots by SK growth using molecular beam epitaxy (MBE). Specifically, the following is disclosed. That is, when a quantum dot structure made of InAs is formed on a GaAs (001) substrate, when the amount of InAs deposited on the substrate is 1 ML (molecular layer), layer growth is performed, and a GaT from the substrate, which is a wetting layer to some extent, is formed. A GaInAs layer containing atoms is formed. Then, when the deposition amount increases to about 1.7 ML, a three-dimensional InAs island appears on the wetting layer, and quantum dots are formed. Furthermore, when the deposition amount increases to reach 2.2 ML or more, the quantum dots come into contact with each other.

  However, in such a manufacturing method, it is difficult to control the position of the quantum dots, resulting in disordered arrangement and large variations in the shape of the formed quantum dots. As a result, the density of states also fluctuates, the optical gain spectrum at the time of laser oscillation becomes a very wide spectrum, and the quantum size effect is not sufficiently exhibited.

In addition, in the quantum dot structure, it is necessary to increase the density in order to obtain a sufficient optical gain, but in the single-layer quantum dot structure, the surface density of the quantum dots, that is, the dot filling rate in the surface is reduced. Therefore, it is difficult to obtain a sufficient optical gain.
For this reason, in the conventional quantum dot structure, multilayering is indispensable for increasing the density. However, the number of quantum dots that can be multilayered while maintaining a high-quality crystal due to the strain energy accumulated in the quantum dots. As a result, it is difficult to obtain sufficient optical gain.

  The present invention has been made in view of the above problems, and by using a quantum nanostructure such as a high-density quantum dot in which the position of the quantum dot is controlled, the output of the semiconductor laser is increased, the threshold operation is reduced. An object of the present invention is to provide a semiconductor device with improved performance such as power consumption driving and improvement of light receiving sensitivity of a light receiving element.

According to the first aspect of the present invention, at least two compositions or band gaps different from those of the semiconductor substrate are used.
A semiconductor device having a waveguide layer or an absorption layer including more than one type of quantum nanostructure, wherein the lattice constant of each quantum nanostructure constituting the quantum nanostructure is positive or negative with respect to the lattice constant of the semiconductor substrate. The quantum nanostructure is formed on a layer structure having a crystal plane orientation inclined in the <011> direction from the (100) plane orientation, and the surface of the layer on which the quantum nanostructure is formed has A step formed by the inclined crystal plane orientation; and a stripe formed in a <011> direction, wherein the quantum nanostructure is a region where the step and the stripe intersect, and the stripe is formed by a semiconductor layer. If formed, the half
When formed on a conductor layer and the stripe is formed by a dielectric mask,
The dielectric mask is formed in a region where it is not formed.

The invention according to claim 3 is characterized in that the quantum nanostructure includes at least one of a quantum dot, a quantum box, and a quantum dash.

The invention according to claim 4 is characterized in that the quantum nanostructure is formed by a self-formation or self-organization phenomenon during crystal growth.

In the invention according to claim 2, the layer in which the quantum nanostructure is formed is based on the lattice constant of the semiconductor substrate.
The region having a larger lattice constant has a quantum nanostructure having compressive strain, and the semiconductor substrate
The region having a lattice constant smaller than that of the plate has a quantum nanostructure having tensile strain .

The invention according to claim 5 is characterized in that the quantum nanostructure is formed on a layered structure whose crystal plane orientation is (n11).

The invention according to claim 6 is characterized in that the surface orientation of the semiconductor substrate is (n11).

The invention according to claim 7 emits light by current injection.

  According to the present invention, a semiconductor device having a high-density quantum nanostructure can be realized. In particular, a high-density quantum nanostructure can be applied to an active layer that functions as a waveguide layer of an optical active device such as a semiconductor laser or an absorption layer of an optical passive device such as a modulator. A semiconductor device having such an active layer can significantly reduce the oscillation threshold, improve the high output operation, reduce the power consumption, and improve the temperature characteristics of the oscillation characteristics.

  Embodiments of a semiconductor device according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a semiconductor device according to the present invention, specifically, a semiconductor laser device.

  The semiconductor laser device shown in FIG. 1 has a lower clad layer 2A, a lower SCH layer 3A, an active layer 4, an upper SCH layer 3B, an upper clad layer 2B, and a contact layer 5 on a semiconductor substrate 1. An electrode 6A is formed on the contact layer 5, and an electrode 6B is formed on the surface of the semiconductor substrate 1 opposite to the surface on which the lower cladding layer 2A is formed.

  The active layer 4 is formed of a quantum dot layer 100 and a barrier layer 101. Further, the quantum dot layer 100 includes a quantum dot region 100A composed of a wetting layer 100A-1 and a quantum dot 100A-2, and the quantum dot region 100A includes quantum dots 100B having different compositions.

In general, in the quantum dot layer, the quantum dot filling rate in the surface of the layer is smaller than that of a commonly used quantum thin film structure. . In the present embodiment, two types of quantum dot regions 100A having different compositions are used.
Since the barrier layer is formed after the quantum dots 100B are formed, the occupation ratio of the quantum dots per one quantum dot layer is larger than that of the conventional structure. Further, before forming the barrier layer 1 01, between the quantum dots 100A-2 of the first quantum dot regions 100A, since as to be embedded in the second quantum dot 1 00B, due to crystal defects rolling The position can be suppressed.

The positive grid constants of the quantum dot region 100A with respect to the semiconductor substrate, by a negative relative to the quantum dot 100B lattice constant of the lattice constant a semiconductor substrate 1 of, the crystal strain in the in-plane direction It can be configured to compensate. Thereby, compared with the conventional quantum dot, it is possible to realize a quantum dot structure having excellent crystallinity with few crystal defects and dislocations even when the number of layers is increased. Note that positive and negative relationships reverse, or negative lattice constants before Symbol quantum dot region 100A with respect to the semiconductor substrate may be positive relative to the lattice constant of the lattice constant of the semiconductor substrate 1 of the quantum dot 100B.

  Further, by controlling the composition wavelength of the quantum dot region 100A and the quantum dot 100B, not only the wavelength band of the oscillation wavelength and the optical gain but also the confinement of carriers can be controlled.

  In other words, when the difference between the two composition wavelengths is large, the quantum dots with the small composition wavelength function as a barrier in the in-plane direction, and in addition to the light confinement in the in-plane direction, the injected carriers are injected into the quantum dots with the large composition wavelength. Can concentrate.

  On the other hand, when the difference in composition wavelength between the two is small, carriers are also injected into quantum dots with a small composition wavelength, and the two quantum dots function as well layers, so they have optical gain over a wide wavelength range. The semiconductor laser device can be configured.

Here, in the present embodiment, the lowermost barrier layer 101 of the active layer 4 also serves as a base layer. The underlayer is provided to control the size and shape of the quantum dots in order to achieve a desired wavelength. The active layer 4 and the lower SCH layer 3 are independent of the lowermost barrier layer.
A can be formed between A. The underlying layer may also be formed in the active layer 4.
In this case, it is preferable to form an underlayer between the barrier layer 101 and the wetting layer 100A-1. Note that the underlayer can be formed at a plurality of locations.

  It should be noted that the size and shape of the quantum dots can be controlled by using the underlying layer as a strained layer. As a result, the control region of the emission wavelength of the semiconductor laser device can be widened.

In particular, the positive grid constants of the quantum dot region 100A with respect to the semiconductor substrate (negative), the negative lattice constant of the quantum dot 100B relative to the lattice constant of the semiconductor substrate 1 (positive) and when the base layer 102 If a strain compensation structure in which the lattice constant changes positively or negatively with respect to the semiconductor substrate 1 in the plane, the following effects can be obtained. That quantum dots having a compressive strain in the region of the base layer having a larger lattice constants than the lattice constant of the semiconductor substrate 1 (base layer having a compressive strain), a smaller lattice constants than the lattice constant of the semiconductor substrate 1 Quantum dots having tensile strain can be formed preferentially in the region of the underlying layer (underlayer having tensile strain). In this way, the position of the quantum dot can be controlled more accurately.

  This is because the quantum dots are formed so that the strain energy stored in the quantum dots is minimized. For example, a quantum dot having compressive strain has a smaller strain energy accumulated in the dot when grown in the region of the underlayer having compressive strain than in the region of the underlayer having tensile strain.

The semiconductor laser device according to this example will be described. FIG. 2 is a cross-sectional view of the semiconductor laser device according to this example. Here, FIG. 2 (a) shows a longitudinal sectional view of the longitudinal direction, FIG. 2
(b) shows sectional drawing parallel to a light-projection surface. The semiconductor laser device according to this example includes an n-type lower cladding layer 2A, an undoped lower SCH (light confinement) layer 3A, an active layer 4, and an undoped upper SCH (light confinement layer) on an n-type InP semiconductor substrate 1. ) 3B, p-type upper I
The nP cladding layer 2B and the p-type GaInAsP contact layer 5 are sequentially stacked. These layers are formed by epitaxy crystal growth techniques such as MOCVD and MBE.
It is formed in order on the type InP semiconductor substrate 1.

An n-type lower electrode 6B is formed on the lower surface of the n-type InP semiconductor substrate 1, and a p-type upper electrode 6A is formed on the contact layer 5. The semiconductor layer 9 of p-type semiconductor layer 8 and the n-type shown in FIG. 2 (b) to form a current blocking layer. The p-type semiconductor layer 8 and the n-type semiconductor layer 9 are formed in adjacent regions of a mesa structure (the lower light confinement layer 3A, the active layer 4, and the upper light confinement layer 3B) formed by a photolithography technique and an etching process. Is done. Due to the presence of the current blocking layer, the active layer 4 functions as a constriction region for the injected current and realizes a stable horizontal single transverse mode. As long as a stable horizontal single mode can be realized, the shape of the mesa may be a tapered shape or a shape having a plurality of mesas with different mesa widths. Furthermore, in the present invention, the BH structure is used in order to realize a more stable horizontal single mode. However, a ridge structure or a SAS (self-aligned type) structure may be used as long as the lateral mode is controlled. .

Furthermore, as shown in FIG. 2 (a), the semiconductor laser device, the resonance by the rear end face of the light is formed by the front end face and the cleave plane opposed thereto formed in it and the cleavage plane at the surface is emitted A device length L is defined. A low reflection film 11 is coated on the front end surface so that light emission from the front surface of the resonator is easy, and a high reflection film is formed on the rear end surface so that light emission from the rear surface is suppressed. 12 is coated.

  Here, in this embodiment, the resonator length is set to 1300 μm in order to realize high output operation, but from the viewpoint of high output operation, it is 800 μm or more, preferably 1000 μm or more, and more preferably 1500 μm or more. Is desirable. On the other hand, in a laser that requires low threshold operation and high-speed modulation operation such as signal light source use, the resonator length is desirably 400 μm or less, and more desirably 300 μm or less. As described above, the optimum resonator length is determined from specifications such as a desired optical output, power consumption, and operating current of the laser module.

  In order to realize a high output operation, it is preferable to optimize not only the resonator length but also the reflectance of the low reflective film 11 according to the resonator length. For example, in a semiconductor laser device having a resonator length of 1000 μm or more, the low reflection film is preferably 5% or less, more preferably 3% or less. In this example, since the resonator length is 1300 μm, the reflectance of the low reflective film 11 is 1.5%. When the resonator length is 1000 μm or more and an external resonator such as a fiber Bragg grating is provided, the reflectance is preferably 1% or less. On the other hand, the reflectance of the high reflection film 12 is desirably 90% or more for the light output operation, but is 98% in this embodiment.

Here, the active layer 4 has a multiple quantum well (MQW) structure including a quantum dot structure, and the SCH layers 3A and 3B arranged so as to sandwich the active layer 4 have a GRIN-SCH structure.
FIG. 3 shows a band gap diagram between the conduction band and the valence band of the lower cladding layer 2A to the upper cladding layer 2B of the semiconductor laser device of this embodiment, that is, an energy band gap diagram in the stacking direction. As shown in FIG. 3, in the active layer 4, the quantum dot layers 100 and the barrier layers 101 are alternately adjacent and heterojunctioned, and the active layer 4 has an MQW structure having three wells.

As shown in FIG. 3, each of the SCH layers 3A and 3B has a plurality of layers 3A ₁ , 3A ₂ ,..., 3A _n and 3B _{1 in which} the band gap energy of each layer increases stepwise as the distance from the active layer 4 increases. , 3B ₂ ,..., 3B _n , a GRIN-SCH structure.
In the present embodiment, the composition wavelength of the barrier layer 101 of the active layer 4 is 1.2 μm, and the SCH layers 3A and 3B made of GaInAsP have composition thicknesses of 0.95 μm, 1.0 μm, 1. The layers were formed of 05 μm, 1.1 μm, 1.15 μm, and 1.2 μm.

  Further, it is desirable that the thickness (total) of each of the SCH layers 3A and 3B is 200 nm or less, preferably 100 nm or less, more preferably 30 to 40 nm, to meet the required optical output and threshold current specifications. Optimized accordingly.

In this embodiment, a multi-stage GRIN-SCH structure in which the band gap energy changes linearly as the optimum structure is adopted as the SCH layer. However, this is not limited as long as a desired output can be obtained.
In this embodiment, the upper SCH layer 3A and the lower SCH layer 3B are formed so that the position, thickness, and composition are all symmetrical with respect to the active layer 4. However, the lower SCH layer 3A is formed from the upper SCH layer 3B. A thick asymmetric structure may be used.

  The energy band relationship between the active layer 4, the SCH layers 3A and 3B, and the cladding layers 2A and 2B is such that the energy band gap of the quantum dot layer 100 in the active layer 4 (MQW structure) is the smallest, and then the active layer 4, the energy band gap increases in the order of the barrier layer 100, the SCH layers 3A and 3B, and the cladding layers 2A and 2B.

The quantum dot structure of this example has a quantum dot 100A- 2 made of InAs with a layer thickness of 5 nm.
A strained multiple quantum well structure comprising a quantum dot layer 100 comprising a quantum dot region 100A comprising GaAs, a quantum dot 100B comprising GaAs having a layer thickness of 5 nm, and a barrier layer 101 comprising GaInAsP having a layer thickness of 10 nm.

  In this embodiment, in order to control the size and position of the quantum dots, as shown in FIG. 4, the semiconductor substrate 1 made of InP inclined by 2 ° from the (100) crystal plane is used, and the first quantum dot layer A stripe 200 made of GaInAsP having a thickness of 5 nm was formed in the <011> direction on the barrier layer 101 on which 100 is formed.

  In the semiconductor substrate 1 made of InP inclined by 2 ° from the (100) crystal plane, steps are formed in the <011> direction on the surface of the semiconductor substrate 1. Since this step is transferred to each semiconductor layer formed on the semiconductor substrate 1, a step is also formed on the surface of the barrier layer 101 on which the first quantum dot layer 100 is formed. In addition, since the stripe is formed perpendicular to the step, a region where the step and the stripe intersect is a region having the lowest surface energy, and quantum dots are preferentially formed in this region.

  For this reason, it has been difficult to control the position of the quantum dots in the past, but in this embodiment, the position can be controlled such that the quantum dots are arranged in a region where the step and the stripe intersect. Further, the density, shape, and size of the quantum dots can be controlled by the shape and interval of the stripe to be formed.

Here, since the quantum dot (not shown) made of GaAs has a larger band gap than the quantum dot 100A- 2 made of InAs, carriers are not injected into the quantum dot made of GaAs at the time of carrier injection. This quantum dot functions as a barrier layer in the in-plane direction. Further, since in-plane direction refractive index of the quantum dot region 100 A is larger than the quantum dots of GaAs, the light is confined in the quantum dots 100A- 2. The band gap energy of the quantum dot 100A- 2 is GaInAsP.
Therefore, carriers are not injected into the barrier layer 101 during current injection. Further, the stripe 200 made of GaInAsP is also a quantum dot 1.
Since the band gap is larger than 00A- 2 , carriers are not injected. As a result, carrier injection is efficiently performed only on the quantum dots 100A- 2 . At this time, since the quantum dots 100A- 2 have the same size, the line width of the optical gain is narrow and the strength is high. Therefore, a semiconductor laser device that oscillates at a low current and operates with high efficiency can be obtained.

In this embodiment, the active layer 4 is doped with n-type impurities at 7 × 10 ¹⁷ cm ⁻³ to reduce the element resistance and the thermal resistance, and can operate with low power consumption and high output even at a high injection current. The laser structure was a good one. The impurity doping may be performed on at least a part of the pair including the quantum dot layer 100 constituting the multiple quantum well structure and the barrier layer 101 adjacent to the quantum dot layer 100, and is not necessarily performed on all of the pairs. Depending on the desired light output value, there is no problem whether the active layer 4 has a structure doped with p-type impurities or the active layer 4 has no impurity doped.

  In the present embodiment, it is preferable that the semiconductor substrate 1 is formed of InP and the active layer 4 and the SCH layers 3A and 3B are formed of InGaAsP as described above. However, other materials may be used. Is possible. For example, the semiconductor substrate 1 is formed of InP and the active layer 4 and the SCH layers 3A and 3B are formed of AlGaInAsP, or the semiconductor substrate 1 is formed of GaAs and the active layer 4 and the SCH layers 3A and 3B are formed of AlGaInP, AlGaInNAsP, or GaInAsP. It may be formed by, for example. In this embodiment, the conductivity type of the semiconductor substrate 1 is n-type. However, the conductivity type of each layer formed thereon can be changed in accordance with the p-type.

Furthermore, the semiconductor laser device of this embodiment has various other laminated structures as long as it has a waveguide layer or an absorption layer including at least two types of quantum nanostructures having different compositions or band gaps from the semiconductor substrate. The present invention can be applied to a realized semiconductor laser device.
For example, a laser of multiple oscillation longitudinal modes below a predetermined output value is generated by the wavelength selective characteristic of a distributed feedback (DFB) laser device, a distributed Bragg reflection (DBR) laser device, or a grating formed near the active layer. The present invention can be applied to a semiconductor laser device, a surface emitting laser device, a modulator, and the like. From the viewpoint of the volume filling rate of quantum dots, an active layer composed of three or more quantum dot layers is more suitable.

  In this embodiment, the semiconductor laser device using quantum dots has been described as an example. However, instead of the quantum dots, quantum boxes, quantum dashes, quantum wires, and quantum disks are used as quantum nanostructures. You can also combine some of these.

In this embodiment, a stripe formed by a semiconductor layer is used, but a stripe formed by a dielectric mask made of silicon oxide, silicon nitride, or the like can also be used. In this case, the position, shape, and size of the quantum dots can be controlled by taking advantage of the feature that the growth is selectively performed in the region without the dielectric mask. This is because the supply amount of atoms for effectively forming quantum dots on the surface to be grown varies depending on the shape of the dielectric mask.
In addition, in semiconductor laser devices using stripes using such a dielectric mask, when quantum dots are formed by metal organic vapor phase epitaxy, the lower the pressure during growth, the greater the growth selectivity. With a growth pressure of about 20 Torr, a high-density quantum dot structure can be realized without forming a polycrystal on the mask regardless of the crystal direction of the dielectric mask to be formed.

  In this example, a semiconductor substrate made of InP inclined by 2 ° from the (100) crystal plane was used. However, the semiconductor substrate is not limited to such a (100) crystal plane and has a specific crystal plane orientation. Even if the (n11) substrate or the (100) crystal plane is used as the substrate and the crystal plane formed by etching is used, the same effect can be obtained by the same method.

  From the above results, according to the present invention, a semiconductor device having a high-density quantum nanostructure can be realized. In particular, a high-density quantum nanostructure can be applied to an active layer that functions as a waveguide layer of an optical active element such as a semiconductor laser device or a semiconductor amplifying device. In particular, the semiconductor laser device having such an active layer has the effects that the oscillation threshold can be greatly reduced, the high output operation, the low power consumption operation, and the temperature characteristics of the oscillation characteristics can be improved.

  Further, according to the present invention, a high-density quantum nanostructure can be applied to a layer that functions as an absorption layer of an optical passive element such as a modulator or a light receiving element. In particular, a semiconductor device having such a layer has an effect that a high-performance optical switch capable of increasing the extinction ratio can be realized by utilizing a large change in refractive index when an electric field is applied.

  The present invention can also be applied to electronic devices.

It is sectional drawing of the semiconductor laser apparatus of a present Example. It is sectional drawing of the semiconductor laser apparatus shown in FIG. 2A shows a longitudinal sectional view in the longitudinal direction, and FIG. 2B shows a sectional view parallel to the light emitting surface. FIG. 2 is a diagram showing a band gap diagram between a conduction band and a valence band in a semiconductor laser device shown in FIG. 1 from a lower cladding layer to an upper cladding layer. It is a perspective view which shows the quantum dot layer vicinity of the semiconductor laser apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2A Lower clad layer 2B Upper clad layer 3A Lower SCH layer 3B Upper SCH layer 4 Active layer 100 Quantum dot layer 101 Barrier layer 5 Contact layer 6A Upper electrode 6B Lower electrode 8 Semiconductor layer 9 Semiconductor layer 11 Low reflection film 12 High Reflective film

Claims (7)

A semiconductor device having a waveguide layer or an absorption layer including at least two types of quantum nanostructures different in composition or band gap from a semiconductor substrate,
The lattice constant of each quantum nanostructure constituting the quantum nanostructure is positively or negatively different from the lattice constant of the semiconductor substrate,
The quantum nanostructure is formed on a layer structure having a crystal plane orientation inclined in a <011> direction from a (100) plane orientation,
The surface of the layer where the quantum nanostructure is formed has a step formed by the inclined crystal plane orientation, and a stripe formed in the <011> direction,
The quantum nanostructure is a region where the step and the stripe intersect,
When the stripe is formed of a semiconductor layer, it is formed on the semiconductor layer,
When the stripe is formed by a dielectric mask, the dielectric mask is formed.
A semiconductor device formed in a non- processed region . The layer in which the quantum nanostructure is formed is
A region having a lattice constant larger than the lattice constant of the semiconductor substrate has a quantum having compressive strain.
Has a nanostructure,
An amount having tensile strain in a region having a lattice constant smaller than that of the semiconductor substrate
The semiconductor device according to claim 1, having a child nanostructure . The semiconductor device according to claim 1, wherein the quantum nanostructure includes at least one of a quantum dot, a quantum box, and a quantum dash. 4. The semiconductor device according to claim 1, wherein the quantum nanostructure is formed by a self-formation or a self-organization phenomenon during crystal growth. 5. 5. The optical semiconductor device according to claim 1, wherein the quantum nanostructure is formed on a layer structure having a crystal plane orientation of (n11). 6. 6. The surface orientation of the semiconductor substrate is (n11).
The semiconductor device according to item. The semiconductor device according to claim 1, wherein the semiconductor device emits light by current injection.

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