JP2945546B2 - Stripe laser diode and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a laser diode, and more particularly to an improvement in a laser diode having a stripe structure.

With the widespread use of laser diodes in society, for example, storage of information on a magneto-optical disk, reading of a bar code in a so-called POS system, or optical recording performed in a printer, light at a short wavelength, particularly a visible light wavelength, is used. There is a need for a laser diode that can generate a beam. If a short wavelength beam can be used in the field of optical recording, the recording capacity of an optical information recording device can be greatly increased. The use of visible light is also advantageous in other fields, such as POS devices.

In an optical information recording apparatus for recording and reproducing information on a recording medium by using a converging light beam, a laser diode is used to generate a light beam other than the ordinary conditions such as low threshold current, high output, and high reliability. Low astigmatism is required. Particularly, in an optical recording / reproducing apparatus, it is desirable that the light beam has a very small and circular beam shape when converged on a recording medium such as an optical disk. If the astigmatism is large, the light beam has a long and thin elliptical shape having a circular shape, and the major axis direction of the ellipse changes depending on the imaging state of the focal point. Various efforts have been made to solve such an astigmatism problem.

[0004]

2. Description of the Related Art FIG. 41 shows a configuration of a conventional laser diode having a so-called ridge structure and capable of forming a light beam in a visible wavelength range.

Referring to FIG. 41, a laser diode is formed on a (100) plane of an n-type GaAs substrate 101. On the (100) plane, a buffer layer 102 of n-type GaAs is epitaxially grown, and on the buffer layer 102, an intermediate layer 103 of n-type InGaP is epitaxially grown.

On the intermediate layer 103, an n-type InGaAlP
A cladding layer 104 is epitaxially grown,
Further, an active layer 105 made of undoped InGaP is epitaxially grown on the cladding layer 104. On the other hand, on the active layer 105, a clad layer 106 made of p-type InGaAlP is formed.
An etching stopper layer 107 made of nGaP is formed on the cladding layer 106. Furthermore, p-type InGaAl
Another cladding layer 109 made of P and an intermediate layer 110 made of InGaP are sequentially formed to form a layered semiconductor structure. Furthermore, a silicon oxide layer (not shown) is deposited on the layered semiconductor structure on the layer 110. The deposited silicon oxide layer is patterned corresponding to the ridge structure, and the layered semiconductor structure is subjected to wet etching using the patterned silicon oxide layer as a mask. As a result of the etching, a ridge structure including the layers 109 to 110 is formed, and n-type GaAs is deposited using the same silicon oxide mask. As a result, n-type Ga
As regions 108a and 108b are formed on both sides of the ridge structure as shown.

In the structure shown in FIG . 41 , the ridge structure is formed so as to be supported by the n-type GaAs regions 108a and 108b from the left and right . Therefore, the ridge structure forms a so-called loss guide and is formed in the active layer 105. The emitted light is guided along the ridge structure. This is because GaAs on both sides of the ridge structure has a smaller band gap than InGaP or InGaAlP and absorbs light formed in the active layer, and as a result, the refractive index changes in the regions 108a and 108b. Further, in such a ridge structure, since the GaAs regions 108a and 108b on both sides of the ridge are doped with n-type, the drive current is also subjected to current constriction so as to flow through the ridge structure. As a result of such current constriction, FIG.
Laser diodes have the advantage of a low threshold. Also,
Since InGaP is used for the active layer 105, about 68
Oscillation at a wavelength of 0 nm is possible. That is, FIG.
Can oscillate in the visible light region.

On the other hand, the laser diode shown in FIG. 41 has a problem that the generated light beam includes astigmatism. More specifically, the position of the focal point of the light beam emitted from the end face of the laser diode differs depending on whether the diverging surface of the beam is horizontal or vertical to the active layer. FIG.
2 is a diagram showing the problem of astigmatism, showing a case where a light beam emitted from a laser diode has two focal points f ₁ and f ₂ . That is, while the light beam diverges from the first focal point f _{1 in} the vertical plane, it diverges from the second focal point f _{2 in} the horizontal plane, and the focal points f ₁ and f ₂ are separated from each other by several microns. I have. Since the focus is shifted as described above, the light beam has an elliptical beam shape that is not preferable in an optical information recording device or the like. As described above, the major axis direction of the elliptical beam changes depending on the focusing state of the light beam.

It is considered that such astigmatism is mainly caused by the difference between the efficiency of light confinement in the horizontal direction and the efficiency of light confinement in the vertical direction with respect to the active layer. That is, as long as a loss guide structure having no refractive index structure for confining light in the lateral direction is used, the problem of astigmatism cannot be solved. In order to solve the problem of astigmatism, the inventor of the present invention has previously published European Patent Application Publication No. 0454476.
A laser diode in which a mesa structure is formed on a substrate and an active layer is formed so as to extend along the mesa structure was proposed.

FIG. 43 shows the structure of the laser diode proposed in the prior art.

Referring to FIG. 43, a laser diode is formed on a GaAs substrate 201 doped with, for example, p-type, and the substrate is formed to have a (100) main surface. Further, a mesa structure 201a is formed on the substrate 201, which is defined by a main surface composed of a (100) plane and side walls composed of a (111) B plane formed on both sides thereof. The (100) plane forming the mesa structure 201a extends in the longitudinal direction of the laser diode, and forms a basic structure of a stripe structure.

A current confinement structure 202 is formed on the substrate 201 thus formed by epitaxially depositing n-type GaAs with the main surface of the mesa structure 201a covered with a silicon oxide mask. (11) extending obliquely to the (100) plane of the GaAs substrate 201
1) When epitaxial growth is performed on the B plane,
(Since the growth rate of the (311) B plane is slow, the (311) B plane tends to develop selectively. In other words, the epitaxial layer 202 thus formed extends to both sides of the mesa structure 202a. And has a (311) B plane inclined with respect to the (100) plane of GaAs.
As a result, the (311) B plane forms another mesa structure extending in conformity with the stripe structure of the laser diode.

After the layer 202 is formed and the mask is removed, a buffer layer 203 made of p-type GaAs is epitaxially grown to obtain a good crystal plane required for the subsequent epitaxial growth . 11
An intermediate layer 204 of p-type InGaP corresponding to 0 is epitaxially grown on the buffer layer 203. A cladding layer 205 made of p-type InGaAlP is further epitaxially grown on the intermediate layer 204, and an active layer 20 made of undoped InGaP is further formed on the cladding layer 205.
6 is epitaxially grown. . That is, the laser diode of FIG. 41 can oscillate in the visible light region.

Further, an n-type InGa
A clad layer 207 of AlP is epitaxially grown, and n-type InGaAs corresponding to the intermediate layer 103 of FIG.
An intermediate layer 208 of IP is epitaxially grown. Further, a contact layer 209 made of n ⁺ -type GaAs is epitaxially grown on the intermediate layer 208, and an upper electrode and a lower electrode (not shown) are formed on the upper main surface of the contact layer 209 and the lower main surface of the substrate 201, respectively. Is formed. These epitaxial layers are formed by MOCVD because they require precise control of the composition, and dopants are introduced as needed during the epitaxial process. Usually, An is used as the p-type dopant, and Se or Si is used as the n-type dopant. Zn is introduced by mixing dimethyl zinc ((CH ₃ ) ₂ Zn) with a source gas for forming an epitaxial layer, while Se is selenium hydride (H ₂ S).
e) is introduced by mixing. When Si is used, silane (SiH ₄ ) or disilane (Si ₂ H ₆ ) is used.

In the laser diode of FIG. 43, a forward bias voltage is applied between an upper electrode and a lower electrode to
The operation is performed by injecting carriers into the cell. In the illustrated example, holes are injected into the p-type substrate 201 and the active layer 20 is removed.
6, and when passing through the mesa structure 201a, the n-type GaAs layers 202 formed on both sides of the mesa structure 201a cause a narrowing effect of carriers. As a result, holes are selectively injected into the central portion of the cladding layer 205, and further flow from the cladding layer 205 to the active layer 206, where the layers 209, 20
The electrons recombine with the electrons injected into the active layer 206 through 8 and 207. The recombination of the electron and the hole causes a well-known stimulated emission, and a reflector is provided at both ends in the longitudinal direction of the laser diode to reflect the light beam back and forth, thereby amplifying the light beam.

In such a laser diode configuration, all of the layers 203 to 209 have a shape matching the surface shape of the second mesa structure, and each layer has a mesa structure 201.
An elongated stripe region characterized by a (100) plane corresponding to the (100) plane of a is formed. Further, each stripe region is defined in the lateral direction by a slope having a plane index (311) B corresponding to the (311) B plane of the layer 202 formed on both sides of the (100) plane. Of course, the (100) plane is flat and extends parallel to the upper main surface of the mesa structure 201a. In such a structure, the light beam is confined in the stripe region of the active layer due to the light confinement effect in the lateral direction, so that the recombination of carriers mainly occurs in the stripe region of the active layer. Can solve the problem.

[0017]

In such a structure, since each epitaxial layer has a crystallographically non-equivalent plane, the properties of the epitaxial layer change depending on the orientation of the crystal plane. Occurs.

In the apparatus shown in FIG.
5 is composed of three regions each characterized by three crystallographically unequal crystal planes. That is, the first region is a region characterized by the (100) plane, the second and third regions are characterized by the (311) B plane, and are formed on both sides of the first region. Extend in the longitudinal direction or the optical axis direction. As will be discussed in detail later, it has been found that in such a structure, the dopant concentration level changes in the first to third regions of the cladding layer 205. More specifically, the concentration level of Zn is (311) B
The second and third regions characterized by the plane are higher than in the first region characterized by the (100) plane, and the carrier density increases with the change in the concentration level of the dopant. There is a tendency that the region is higher than the first region. When such a change in the carrier density occurs, the resistivity of the cladding layer 205 becomes higher in the first region than in the second and third regions on both sides of the first region, and the injected current becomes as shown by an arrow in FIG. Tends to flow preferentially in the slope region rather than in the stripe region. In other words, the injected driving current flows bypassing the stripe region of the active layer 206, and the effect of current constriction is reduced, and the efficiency of the laser diode is also reduced.

Further, the conventional laser diode shown in FIG. 43 has a problem in that the concentration of Zn contained in the epitaxial layer is low. More specifically, since the Zn concentration in the epitaxial layer is low, the hole concentration is low in the p-type layer. Therefore, the conventional laser diode has a problem that the resistance is large and a large output cannot be obtained. That is, in such a laser diode, when the injection current is increased, excessive heat is generated. The reason for the low Zn concentration in such an epitaxial layer is that MOCVD
It is believed that the vapor pressure of Zn, which is in equilibrium with the crystal phase during the process, is high, so that Zn evaporates from the crystal phase and concentrates in the gas phase. Therefore, this tendency becomes more remarkable as the growth temperature of the epitaxial phase becomes higher. On the other hand, in order to obtain a high-quality crystal layer, it is desirable to increase the growth temperature. Therefore, the requirement to obtain such a high-quality crystal layer contradicts the requirement to realize a high Zn concentration in the epitaxial layer.

Accordingly, it is a general object of the present invention to provide a new and useful laser diode which solves the above-mentioned problems, and a method for manufacturing the same.

A more specific object of the present invention is to provide a laser diode and a method of manufacturing the same, which can generate a light beam at a visible light wavelength without causing large astigmatism.

Another object of the present invention is to provide a method for forming a laser diode on a substrate having a stripe structure including a crystallographically non-equivalent plane and extending in a predetermined direction. An object of the present invention is to provide a laser diode manufacturing method for manufacturing a laser diode having a low resistance by increasing the concentration.

Still another object of the present invention is to provide a simple laser diode manufacturing method capable of realizing effective current confinement.

[0024]

[Means for Solving the Problems]The present invention has the above object.
To As described in claim 1, on the surface of the semiconductor substrate,
A plurality of extending in parallel with each other in a predetermined direction on the substrate surface
First strike defined by crystallographically non-equivalent crystal faces
A lip structure is formed, and on the surface of the semiconductor substrate, the
InGaAlP layer so as to include a first stripe structure
From the decomposition of the gaseous raw materials of In, Ga, Al and P
While maintaining epitaxy for the semiconductor substrate.
In this case, the InGaAlP layer is provided with the first
Multiple crystallographically non-equivalents corresponding to stripe structures
A second stripe structure defined by various crystal planes is formed.
In a method of manufacturing a laser diode having a configuration,
During the growth of the InGaAlP layer, the In, Ga, A
Adding Mg vapor phase raw material to l and P vapor phase raw materials
The InGaAlP layer is formed by the second strike
A substantially uniform key regardless of the crystal planes forming the
A p-type doping at a carrier concentration,
In the step of doping the GaAlP layer, the vapor phase source of Mg is used.
The supply of material starts the growth of the InGaAlP layer.
Starting before the step of growing the InGaAlP layer
From the beginning to the end of Mg in the InGaAlP layer.
Characterized in that it is introduced at a substantially uniform concentration.
By the method of manufacturing the laser diode, or As described in claim 2, the vapor phase raw material of Mg has a formula
(C _Five H5) _Two Biscyclopentadiene represented by Mg
2. The composition according to claim 1, which contains magnesium.
By way or As described in claim 3, the stripe structure has a structure of <
An upper main surface in a stripe shape extending in the <011>direction;
1> a pair of striped side walls extending in the direction
A mesa structure formed, wherein the upper main surface is a (100) surface
And the side wall surface has a (311) B plane orientation.
A method according to claim 1, or As further described in claim 4, further comprising the InGaAl
After the P layer is formed, an epitaxial layer is formed on the InGaAlP layer.
While maintaining taxi, including the stripe structure
Has a narrower band gap than InGaAlP
Including a step of growing an undoped semiconductor layer as an active layer
A method according to claim 1, or 6. The method as claimed in claim 5, further comprising:
Before the growth of the InGaAlP layer is started,
Forming a p-type semiconductor layer by decomposition of a phase material
The step of forming the p-type semiconductor layer comprises the step of:
To supply p-type dopants other than Mg simultaneously with the raw material
And adding the Mg vapor source to the semiconductor layer vapor source.
By this, it becomes the step of starting the supply of Mg,
From the beginning of the step of forming the InGaAlP layer,
2. The method according to claim 1, wherein the introduction is performed at a concentration level.
By way or As further described in claim 6, further comprising the InGaAl
Before the formation of the P layer is started, the InGaAlP
Than undoped semiconductors with narrower band gaps
Active layer matching the stripe structure on the substrate.
And maintain epitaxy on the substrate
Forming the InGaAlP layer on the active layer.
Doping the InGaAlP layer.
The process involves adding dopants other than Mg in the form of
It is supplied simultaneously with the start of the step of forming the InGaAlP layer.
And introducing Mg to the InGaAlP layer at a sufficient concentration.
Interrupting the supply of Mg after entering
By the method of claim 1, or As described in claim 7, formed on the surface of the semiconductor substrate.
In addition, a plurality including the surface, each being flat with each other in a predetermined direction.
Defined by crystallographically non-equivalent crystal planes extending in rows
A first stripe structure, and the first
In, Ga, Al, etc.
And the decomposition of the gaseous phase material of P
InGaAl formed while maintaining epitaxy
P layer and the first stripe on the InGaAlP layer.
It is formed corresponding to the structure and has several crystallographically
On the crystal face And a second stripe structure more defined
In the method for manufacturing a laser diode, the InGaAs
During the growth of the IP layer, the vapor of In, Ga, Al and P
P-type dopant and n-type dopant in gas phase
By adding in the form of raw materials, the InGaAlP layer
The electrical properties are determined by the drive current of the laser diode,
At least one of the first and second stripe structures
The InGaAs is formed so as to selectively flow on a specific crystal plane.
characterized in that it is changed according to the crystal plane of the IP layer.
Depending on the method of manufacturing the laser diode, or 9. The plurality of crystallographically unequals as recited in claim 8.
Valuable crystal planes include (100) plane and (311) B plane.
The step of doping the InGaAlP layer is a p-type dopant.
-Mate gas phase raw material as punt and n-type dopant
And a step of simultaneously adding the gaseous raw material of Se and
The concentration of Se is such that the InGaAsP layer is doped p-type.
At this time, the carrier concentration in the region grown on the (100) plane is
The degree is higher than the carrier concentration of the region grown on the (311) B plane.
Claims:
By the method described in item 7, or As described in claim 9, the InGaAlP layer comprises:
Mg causes the Mg concentration in the InGaAlP layer to be:
Each area on (100) plane and (311) B plane
1 × 10 ¹⁸ cm ^-3 Doped to become
Further, Se causes the Se concentration in the InGaAlP layer to decrease.
4 × 10 in the area on the (100) plane ¹⁷ cm ^-3 , (3
11) 8 × 10 in area on plane B ¹⁷ cm ^-3 Will be
9. The method according to claim 8, wherein the doping is carried out.
By or As set forth in claim 10, the plurality of crystallographically non-
Equivalent crystal planes include (100) plane and (311) B plane.
The step of doping the InGaAlP layer is a p-type dopant.
-Mate gas phase raw material as punt and n-type dopant
And a step of simultaneously adding the gaseous raw material of Se and
The concentration of Se is such that the InGaAsP layer is on the (100) plane.
Is doped p-type in the region of
That the region is doped n-type Features Claim
According to the method of Item 7, or The InGaAlP layer as claimed in claim 11.
Is the Mg concentration in the InGaAlP layer due to Mg.
In each region on the (100) plane and the (311) B plane
1 × 10 ¹⁸ cm ^-3 Doped to be
And the Se concentration in the InGaAlP layer is increased by Se.
The degree is 6 × 10 in the area on the (100) plane. ¹⁷ cm ^-3 ,
(311) 1.2 × 10 in area on plane B ¹⁸ cm ^-3
11. The semiconductor device according to claim 10, which is doped to become
By the method described, or As set forth in claim 12, the plurality of crystallographically non-
Equivalent crystal planes include (100) plane and (311) B plane.
The step of doping the InGaAlP layer is a p-type dopant.
-A Zn gaseous source material as a punt and an n-type dopant
And simultaneously adding a vapor phase material of Se and Zn
The concentration of Se is such that the InGaAsP layer is doped n-type.
The carrier concentration level in the region on the (100) plane
(311) It is set to be higher than the area on the B plane.
The method according to claim 7, wherein
Or 14. The InGaAlP layer as claimed in claim 13.
Is the Zn concentration in the InGaAlP layer due to Zn
Is 6 × 10 in the area on the (100) plane. ¹⁷ cm ^-3 To
In the region on the (311) B plane, 1.
8 × 10 ¹⁸ cm ^-3 Doped to become
Thus, the Se concentration in the InGaAlP layer is (100)
1 × 10 in the area on the surface ¹⁸ cm ^-3 , (311) Side B
2 × 10 in the upper area ¹⁸ cm ^-3 Dope to become
The method according to claim 12, wherein
Or As described in claim 14, the plurality of crystallographically non-
Equivalent crystal planes include (100) plane and (311) B plane.
The step of doping the InGaAlP layer is a p-type dopant.
-A Zn gaseous source material as a punt and an n-type dopant
And simultaneously adding a vapor phase material of Se and Zn
The concentration of Se is such that the InGaAsP layer is on the (100) plane.
In the region on the (311) B plane
Claims: It is set to be p-type.
By the method described in item 7, or The InGaAlP layer as claimed in claim 15.
Is the Zn concentration in the InGaAlP layer due to Zn
Is 7 × 10 in the area on the (100) plane. ¹⁷ cm ^-3 To
1. In the region on the (311) B plane,
1 × 10 ¹⁸ cm ^-3 Doped to become
Thus, the Se concentration in the InGaAlP layer is (100)
1 × 10 in the area on the surface ¹⁸ cm ^-3 , (311) Side B
2 × 10 in the upper area ¹⁸ cm ^-3 Dope to become
The method according to claim 14, wherein
Or As set forth in claim 16, the plurality of crystallographically non-
Equivalent crystal planes include (100) plane and (311) A plane.
The step of doping the InGaAlP layer is a p-type dopant.
-A Zn gaseous source material as a punt and an n-type dopant
And simultaneously adding a vapor phase material of Se and Zn
The concentration of Se is such that the InGaAsP layer is on the (100) plane.
In the region on the (311) B plane
Claims: It is set to be p-type.
By the method described in item 7, or 18. The InGaAlP layer as claimed in claim 17
Is the Zn concentration in the InGaAlP layer due to Zn
Is 2 × 10 in the area on the (100) plane. ¹⁶ cm ^-3 To
1 × in the region on the (311) A plane.
10 ¹⁸ cm ^-3 Doped to become
The Se concentration in the InGaAlP layer is (100) plane.
1 × 10 in the upper area ¹⁸ cm ^-3 , (311) on the A side
6 × 10 in the area of ¹⁸ cm ^-3 Doped to be
15. The method according to claim 14, wherein
Or 19. The method of claim 18, further comprising:
An n-type second InGaAlP layer is formed adjacent to the IP layer.
A pn junction between the first and second InGaAlP layers
Are formed corresponding to the region on the (311) A plane.
17. The method of claim 16, further comprising the step of:
By the method described, or As described in claim 19, the plurality of crystallographically non-
Equivalent crystal planes include (100) plane and (311) A plane.
The step of doping the InGaAlP layer is a p-type dopant.
-Zn as punt Gas-phase raw material and n-type dopant
And simultaneously adding a vapor phase material of Se and Zn
The concentration of Se is such that the InGaAsP layer is on the (100) plane.
Region becomes n-type and has the first resistivity.
And in the region on the (311) A plane, the region becomes p-type.
Set to have a greater resistivity of 2
By the method of claim 7, or As set forth in claim 20, the plurality of crystallographically non-
The equivalent crystal plane is a first crystal that corresponds to the main surface of the substrate.
Plane and a second crystal having a different orientation from the first crystal plane.
And the second crystal plane is a step at the substrate surface.
8. The method according to claim 7, wherein a portion is formed.
Or As described in claim 21, the InGaAlP layer is
The doping step is such that the InGaAlP layer is
The first conductivity type in the region on the crystal plane of
To have a second, opposite conductivity type in the region on the crystal plane
21. The method according to claim 20, further comprising:
More or As described in claim 22, the second crystal plane is (3
11) Form A-plane, and the InGaAlP layer is formed by a second
The stripe structure corresponds to the second crystal plane (31)
21. The method according to claim 20, wherein 1) including the A-plane.
By or As described in claim 23, the second crystal plane is (4
11) A step is formed on the substrate, composed of the A surface.
The InGaAlP layer has the second stripe structure.
Structure includes a (411) A plane corresponding to the second crystal plane.
21. The recording medium according to claim 20, wherein:
By the method described above, or As described in claim 24, the first stripe structure.
Forming a structure, as a main surface of the semiconductor substrate,
Forming a crystal plane inclined with respect to the (100) plane;
21. The method according to claim 20, wherein
Or As described in claim 25, Further, the first In
A second separate InGaAlP layer adjacent to the GaAlP layer
Between the first and second InGaAlP layers.
A pn junction is formed except for a region corresponding to the second crystal plane.
Claims characterized by including the step of forming
Item 20; or 27. The method of claim 26, wherein the p-type dopant and
The step of adding the n-type dopant may be performed simultaneously.
Any one of claims 20 to 25, characterized in that:
By the method described in the paragraph, or As described in claim 27, further comprising a source of Ga and As.
By decomposing the material, the GaAs layer is converted to the semiconductor substrate.
While maintaining epitaxy on the plate, the Ga
The As layer corresponds to the first and second stripe structures.
To form a third striped structure
And the third stripe structure includes the first and second stripe structures.
And a crystal plane corresponding to the crystal plane forming the second stripe structure.
Forming a GaAs layer defined by a crystal plane
The process is performed by adding a gaseous raw material of Zn and Se.
The GaAs layer is simultaneously formed by Zn and Se.
The electrical properties of the GaAs layer grow on the (100) plane.
Between the region grown on the other crystal plane and the
8. The method according to claim 7, further comprising the step of doping.
By way or 29. The method as claimed in claim 28, wherein the GaAs layer is doped.
Is performed so that the resistivity of the GaAs layer is set on the (100) plane.
In the grown region, the region grown on another crystal plane
Claims:
27. or 30. The method of claim 29, wherein the GaAs layer is doped.
The GaAs layer is formed by growing the GaAs layer on the (100) plane.
Region becomes p-type and grows on other crystal planes.
And the process is performed so as to be n-type.
By the method of claim 27, or As set forth in claim 30, from the first end to the second end.
A semiconductor substrate extending in the longitudinal direction;
Formed on the substrate in the longitudinal direction.
( 100) plane, and the first stripe plane
On both sides of one of the stripe surfaces, it extends in the longitudinal direction.
Each with a different crystal plane from the (100) plane
Consists of a defined pair of different stripe surfaces
A first stripe structure; Extending longitudinally from a first end to a second end on the substrate;
And is formed so as to exist with the first stripe structure.
Of InGaAlP including a corresponding stripe structure
1 cladding layer; On the first cladding layer, from a first end to a second end
The first strut is formed to extend in the longitudinal direction, and
A stripe structure corresponding to the first structure;
The band gap is narrower than the band gap of the cladding layer.
An active layer composed of an undoped semiconductor material; On the active layer, longitudinally from a first end to a second end
Extending to the first stripe structure.
InGaAlP layer with corresponding stripe structure
A second cladding layer; A first electrode provided on the lower surface of the substrate and in ohmic contact
Means; Ohmic contact provided on the second cladding layer
In a laser diode comprising the second electrode means,
One of the first and second cladding layers is made of Mg.
A substantially uniform darkness regardless of the stripe structure.
The first and second claddings, which are heavily doped
Characterized in that the other of the layers is doped n-type.
By a laser diode, or 32. The method of claim 31, wherein the first conductivity type is doped.
Semi-conductor extending longitudinally from a first end to a second end
A body substrate; Formed as part of the substrate surface, the
A crystal plane having a first crystal orientation extending in the longitudinal direction
A first stripe surface, and the first stripe surface
Is formed to extend in the longitudinal direction adjacent to
A second plane defined by crystal planes having different crystal orientations;
A first stripe composed of two stripe surfaces
Structure; Extending longitudinally from a first end to a second end on the substrate;
A first layer of InGaAlP formed to be
A cladding layer; On the first cladding layer, the first stripe structure
Longitudinally from a first end to a second end in alignment with
Formed to extend as part of the first cladding layer
Corresponding to the first stripe surface,
And extending from the crystal plane having the first crystal orientation.
A third stripe surface formed and the second stripe
The second crystallographic direction, corresponding to the plane, extending in the longitudinal direction.
Fourth stripe surface formed by a crystal plane having a phase
A second stripe structure defined by: On the first cladding layer, from a first end to a second end
Undoped semiconductor material formed to extend in the longitudinal direction
And a first carrier of a first polarity and a second carrier of a first polarity.
A second carrier having a reverse polarity is supplied to the first carrier;
A light beam is formed by recombination of the rear and the second carrier.
An active layer; The first and second stripe structures are arranged on the active layer.
Combined from the first end to the second end in the longitudinal direction,
Formed so as to extend as a part of the layer,
3 corresponding to the stripe surface, extending in the longitudinal direction,
A fifth crystal plane formed from the crystal plane having the first crystal orientation;
Corresponding to the stripe surface and the fourth stripe surface,
A crystal extending in the longitudinal direction and having the second crystal orientation
Defined by a sixth stripe surface formed by the surface
A third stripe structure; On the active layer, longitudinally from a first end to a second end
A fourth layer made of an InGaAlP layer formed so as to extend.
2 cladding layers; The first to third strikes are formed on the second clad layer.
Longitudinally from the first end to the second end in alignment with the loop structure
So as to extend as a part of the second cladding layer.
And corresponds to the fifth stripe surface.
A crystal extending in the longitudinal direction and having the first crystal orientation
A seventh stripe surface formed from the surface and the sixth stripe surface.
The second surface corresponding to the tripe surface and extending in the longitudinal direction;
Eighth strike formed by a crystal plane having a crystal orientation of
A fourth stripe structure defined by a rib surface; Provided on the lower surface of the substrate, in ohmic contact with the
Before the first career The first cladding is formed on the active layer.
First electrode means for injecting through the layer; An ohmic layer provided on the second cladding layer.
Contacting the second carrier with the active layer,
A second electrode means for injecting through a cladding layer of
Laser diode, wherein the first and second laser diodes
One of the lad layers is at least partially p-type dopant and
And n-type dopants
The drive current of the diode is supplied to the active layer and the third
A portion defined by the fifth stripe region in the ip structure
Laser injection characterized by selective injection through
By iod or As described in claim 32, the p-type dopant is
Made of Zn, and the n-type dopant is made of Se
32. The laser diode according to claim 31, wherein
Or As described in claim 33, the first, third, fifth and fifth aspects are described.
And the seventh stripe surface comprises a (100) surface,
The second, fourth, sixth and eighth stripe surfaces are (31
1) The first to eighth stripe surfaces are composed of a B surface.
31. The device according to claim 31, wherein
Or by a laser diode according to 32, or As described in claim 34, the first, third, fifth and fifth aspects are described.
And the seventh stripe surface are the second, fourth, sixth and
Is a pair of (311) B planes forming the eighth stripe plane
Between the side surfaces of the pair of stripes.
The (311) B plane that constitutes the side is seen in the <011> direction
In the first case, the other (311) B plane is <
011> direction, it is inclined in the second opposite direction.
34. The laser diode according to claim 33, wherein:
By or As described in claim 35, the first, third, fifth and fifth aspects are described.
And the seventh stripe surface is formed from a (100) surface,
At this time, the second, fourth, sixth and eighth stripe surfaces are (3
11) The first to eighth stripes formed from plane A
The surface extends in the <01-1> direction.
By a laser diode according to item 31, or As described in claim 36, the first, third, fifth and fifth aspects are described.
And each of the seventh stripe surface is, from the side,
One for forming the second, fourth, sixth or eighth stripe surface;
The pair of (311) A surfaces are sandwiched, and the pair of (311) A
1) One of the A surfaces is the first when viewed in the <01-1> direction.
Tilting in the second direction and the other tilting in the opposite direction
36. The laser diode according to claim 35, wherein:
Or As described in claim 37, the first, third, fifth and fifth aspects are described.
And the seventh stripe surface is inclined with respect to the main surface of the substrate.
The second, fourth, sixth, and the fourth
The stripe plane of No. 8 is different from the crystal plane constituting the main surface of the substrate.
32. The method according to claim 31, wherein the crystal faces are identical.
With the laser diode listed above, or As set forth in claim 38, the first, third, fifth and fifth aspects are described.
And the seventh stripe surface is composed of (311) A surface
The laser diode according to claim 37, wherein
Or As set forth in claim 39, the first, third, fifth and fifth aspects are described.
And the seventh stripe surface is composed of (411) A surface
The laser diode according to claim 37, wherein
Or As described in claim 40, the first and third clips
Either one of the lad layers is at least partially
A first transistor having one of the first and second conductivity types;
A dopant and a second dopant having the other conductivity type
At the same time as the laser diode drive.
Kinetic current is applied to the fifth stripe surface in the active layer.
Form a current constriction structure that selectively injects into the corresponding area
And; The cladding layer forming the current constriction structure is a first sub-block.
A lad layer and a second sub-cladding layer; The first sub-cladding layer includes the first and second dopants.
The doping level at the same time
Wherein the respective doping levels are
The first sub-cladding layer is formed on the fifth stripe surface.
In the corresponding region having the first crystal orientation, the first
Doped to the conductivity type of the dopant To carry again
The density is set to increase, and the sixth strike
In the region having the second crystal orientation corresponding to the live plane
To be doped to the conductivity type of the second dopant.
Set; The second sub-cladding layer comprises the first dopant and
To the first conductivity type by the dopant having the same conductivity type
The first stripe corresponding to the fifth stripe surface.
In a region having a crystal orientation, the sixth stripe surface
Having a higher carrier concentration than the region corresponding to
By the laser diode according to claim 31,
Or 42. The method according to claim 41, wherein the first conductivity type is doped.
Semi-conductor extending longitudinally from a first end to a second end
A body substrate; Formed as part of the substrate surface, the
A crystal plane having a first crystal orientation extending in the longitudinal direction
A first stripe surface, and the first stripe surface
Is formed to extend in the longitudinal direction adjacent to
A second plane defined by crystal planes having different crystal orientations;
A first stripe composed of two stripe surfaces
Structure; Extending longitudinally from a first end to a second end on the substrate;
A first semiconductor comprising a compound semiconductor formed to exist
With a lad layer; On the first cladding layer, the first stripe structure
Longitudinally from a first end to a second end in alignment with
Formed to extend as part of the first cladding layer
Corresponding to the first stripe surface,
And extending from the crystal plane having the first crystal orientation.
A third stripe surface formed and the second stripe
The second crystallographic direction, corresponding to the plane, extending in the longitudinal direction.
Fourth stripe surface formed by a crystal plane having a phase
A second stripe structure defined by: On the first cladding layer, from a first end to a second end
Undoped semiconductor material formed to extend in the longitudinal direction
And a first carrier of a first polarity and a second carrier of a first polarity.
A second carrier having a reverse polarity is supplied to the first carrier;
A light beam is formed by recombination of the rear and the second carrier.
An active layer; The first and second stripe structures are arranged on the active layer.
Combined from the first end to the second end in the longitudinal direction,
Formed so as to extend as a part of the layer,
3 corresponding to the stripe surface, extending in the longitudinal direction,
A fifth crystal plane formed from the crystal plane having the first crystal orientation;
Corresponding to the stripe surface and the fourth stripe surface,
A crystal extending in the longitudinal direction and having the second crystal orientation
Defined by a sixth stripe surface formed by the surface
A third stripe structure; On the active layer, longitudinally from a first end to a second end
A second compound semiconductor layer formed so as to extend;
A cladding layer; The first to third strikes are formed on the second clad layer.
Longitudinally from the first end to the second end in alignment with the loop structure
So as to extend as a part of the second cladding layer.
And corresponds to the fifth stripe surface.
A crystal extending in the longitudinal direction and having the first crystal orientation
A seventh stripe surface formed from the surface and the sixth stripe surface.
The second surface corresponding to the tripe surface and extending in the longitudinal direction;
Eighth strike formed by a crystal plane having a crystal orientation of
A fourth stripe structure defined by a rib surface; Provided on the lower surface of the substrate, in ohmic contact with the
The first carrier is provided on the active layer and the first cladding is provided on the active layer.
First electrode means for injecting through the layer; An ohmic layer provided on the second cladding layer.
Contacting the second carrier with the active layer,
A second electrode means for injecting through a cladding layer of
In the laser diode, the second crystal orientation is:
A crystal plane corresponding to the main surface of the substrate is defined, and the second crystal is formed.
The crystal orientation defines a crystal plane inclined with respect to the main surface of the substrate.
And; One of the first and second cladding layers has at least
Partially one of the first and second conductivity types
And a first dopant having the other conductivity type.
Laser die doped with two dopants
The drive current of the diode is applied to the active layer,
Part defined by the fifth stripe region in the loop structure
Forming a current constriction structure for selective injection through The cladding layer forming the current constriction structure includes first and second cladding layers.
Consisting of two sub-cladding layers; The first sub-cladding layer includes the first and second dopants.
-Doped to each doping level by punting,
At this time, the respective doping levels are adjusted to the first level.
A bucladding layer corresponds to the fifth stripe surface and has a first
The first dopant in a region having a crystal orientation of
And the carrier concentration is increased.
Is set to be large and the sixth stripe surface
In a region having a corresponding second crystal orientation, the second
Set to be doped with the conductivity type of the dopant of; The second sub-cladding layer comprises the first dopant and
To the first conductivity type by the dopant having the same conductivity type
The first stripe corresponding to the fifth stripe surface.
In a region having a crystal orientation, the sixth stripe surface
Having a higher carrier concentration than the region corresponding to
By a characteristic laser diode or As described in claim 42, the first crystal orientation is:
The (311) A plane and the (411) A plane are
Claims characterized by being inclined at an angle in the range between
By a laser diode according to 41, or As set forth in claim 43, the first crystal orientation is:
The (311) A plane is defined.
42, or As described in claim 44, the first crystal orientation is:
The (411) A plane is defined.
42, or As set forth in claim 45, wherein the active layer comprises the first layer.
In a region having a crystal orientation of the second crystal orientation
Characterized in that the thickness is greater than the region having
A laser diode according to claim 41, or As described in claim 46, the first and second clips
Each of the lad layers is formed in a region having the first crystal orientation.
The thickness is larger than that of the region having the second crystal orientation.
It is especially important that Claim 41 or 45.
With the laser diode listed above, or As described in claim 47, the second crystal orientation is:
Crystal plane inclined from (100) plane to (111) A plane direction
Claims 41 to 46, wherein:
By a laser diode according to any one of the above, or As set forth in claim 48, said first stripe structure.
The structure consists of a groove extending in the longitudinal direction on the main surface of the substrate.
The groove is pinched from the side by a pair of opposing side walls.
At that time, the first The stripe surface is the pair of opposing
The second to fourth stripes
The structures are the first cladding layer, the active layer and the active layer, respectively.
And forming a corresponding groove on the second cladding layer,
The second electrode means fills a groove on the second cladding layer.
Having a flattened main surface.
47. A laser diode according to claim 46,
Decide.

[0025]

According to the first feature of the present invention, the distribution of the dopant in the cladding layer can be made substantially constant regardless of the crystal plane under the cladding layer. In other words, unlike the conventional case where Zn is used as a dopant, even when the cladding layer is formed on a stripe structure including a crystallographically non-equivalent plane, the distribution of Mg in the cladding layer is substantially uniform. Can be Therefore, the present invention is particularly effective for avoiding the divergence of the driving current in the laser diode formed on the GaAs substrate having such a stripe structure. Further, by using Mg as a dopant, high-concentration level doping becomes possible. Furthermore, by forming the Mg-doped cladding layer prior to the formation of the undoped active layer, a clear conductivity type boundary can be formed between the cladding layer and the active layer grown thereon. . By shutting off the supply of Mg, the introduction of Mg into the cladding layer is immediately stopped. On the other hand, when Mg doping is performed on a clad layer grown on an active layer that has already been formed, there is a tendency that the incorporation of Mg into the clad layer tends to be delayed. There is a possibility that the boundary of the essential conductivity type deviates from the physical boundary between the active layer and the cladding layer.

According to a second feature of the present invention, an n-type region and a p-type region are formed in the same cladding layer by a single MOCVD method.
The mold region can be formed such that the n-type region is laterally sandwiched between the pair of p-type regions or vice versa. For example, such a structure can be formed by using Mg or Zn as a p-type dopant and further using Se as an n-type dopant. Or p
By appropriately setting the doping levels of the type dopant and the n-type dopant, the carrier density of the portion formed on the first stripe surface in the cladding layer can be set higher than other portions, As a result, current confinement can be performed in the cladding layer, and the operating efficiency of the laser diode is greatly improved. Further, by growing the active layer on the clad layer formed in this way, it is possible to concentrate the current in the active layer corresponding to the stripe structure portion. That is, the shape of the stripe structure formed on the substrate and having a crystallographically non-equivalent stripe surface is the first cladding layer and the active layer formed thereon, and the second cladding layer formed on the active layer. Therefore, in such a structure, a portion of the active layer deposited on the first clad layer corresponding to the first stripe surface is transferred to the first stripe surface. It is configured to be sandwiched from the side by a second cladding layer portion formed on another stripe surface inclined with respect to the other. In other words, the light radiation formed by the active layer is confined vertically and horizontally by the first and second cladding layers, thereby substantially eliminating the astigmatism problem.

According to the third feature of the present invention, it is possible to obtain a cladding layer in which the conductivity type is selectively changed by a single deposition step. Therefore, a laser diode having an excellent current confinement effect can be easily manufactured.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing embodiments of the present invention, experimental facts underlying the present invention will be briefly described.

It is well known that the properties of semiconductor materials change with the crystal plane or orientation. This is also applicable to crystal growth by an epitaxial process, which considers the dependence of physical properties known as crystal anisotropy on plane orientation. In particular, the composition of a semiconductor layer grown by MOCVD may change depending on the crystal plane. For example, In
It has been reported that the amount of Zn introduced into a GaAlP crystal varies depending on the inclination angle of the crystal plane on which epitaxial growth is performed with respect to the (100) plane.

FIG. 1 is a diagram showing the concentration levels of Zn and Mg added to the epitaxial layer made of InGaAlP for each crystal plane. However, the data of Zn and Mg were found by the present inventors (Kondo,
M., Anayama, C., Takanashi, T. And Yamazaki, S., Si
xth International Conference on Metalorganic Vapor
Phase Epitaxy, IEEE Catalog # 92THO459-8, June 8-
11, 1992). FIG. 1 also shows Zn data reported in other documents. Mg and Zn doping is InG
When growing the aAlP layer by MOCVD, Al,
Dimethyl zinc ((C ₅ H) was used as the source gas for In, Ga, and P.
_{5) 2} Mg) or executed by the incorporation of bis (cyclopentadienyl) source gas such as magnesium. In FIG. 1, black circles and white circles, black squares and white squares show the experimental results by the inventor of the present invention, among which white circles and white squares show the results of SIMS analysis, and black circles and black squares show the results of CV measurement. To represent. Table 1 shows the growth conditions by the MOCVD method.

[0031]

[Table 1]

FIG. 1 is a diagram showing the Zn concentration and the Mg concentration in the InGaAlP layer normalized with respect to the Zn concentration on the (100) plane. As shown in FIG. The concentration is (11)
1) It can be seen that as the inclination angle to the A-plane increases, it increases sharply. The Zn concentration becomes substantially maximum when the crystal plane is the (311) A plane, and starts decreasing when the inclination angle is further increased. However, (31) inclined in the (111) A direction
1) The plane forms the Ga plane, and thus becomes the (311) A plane. On the other hand, the (311) plane inclined in the (111) B direction forms the As plane, and thus becomes the (311) B plane. When the crystal plane is inclined toward the (311) B plane as shown as the B direction in the figure, the Zn concentration increases more slowly, and the (311)
It becomes substantially maximum at the inclination angle corresponding to the B surface. If the tilt angle is further increased, the Zn concentration starts to decrease.

On the other hand, in the case of Mg, it can be seen that the Mg concentration level hardly changes even if the crystal plane is inclined in the (311) B plane direction. In other words, the Mg concentration is the same between the (100) plane and the (311) B plane. On the other hand, when the crystal plane is inclined in the (311) A plane direction, M
The g concentration increases with the tilt angle. Further, it can be seen that the Mg concentration is higher than the Zn concentration in any crystal plane. As explained above, this indicates that the equilibrium vapor pressure of Zn is much higher than that of Mg. In other words, Zn easily escapes from InGaAlP into the gas phase by evaporation, and this tendency becomes more pronounced as the deposition temperature is increased.

FIG. 2 shows that S introduced in the InGaAlP layer.
The concentration of e is shown for each crystal plane. InG
The aAlP layer is grown by MOCVD under the same conditions as shown in Table 1. Referring to FIG. 2, the Se concentration is slightly increased in the (311) B plane as compared with the (100) plane,
When the inclination angle exceeds the angle corresponding to the (311) B plane, it suddenly starts increasing. On the other hand, in the direction A, the Se concentration sharply decreases as the inclination angle from the (100) plane increases.

FIG. 3 shows the (100) plane of the InGaAlP layer.
FIG. 8 is a diagram showing the effect of Mg doping on the present invention. See FIG.
In comparison, the source gas of the group III element (C_FiveH
_Five) _TwoThe molar ratio of Mg is 3 × 10^-FourSet to about
4 × 10¹⁷cm^-3Can be obtained. Hope
Good hole concentration about 1 × 10¹⁸cm^-3If
1 × 10^-3Should be set to. Mg is InGaAs
Occupies group III elements in the IP crystal
It acts as a gate and emits holes.

FIG. 4 is a view similar to FIG.
The effect of Zn doping on each crystal plane of 1P is shown.
As shown in FIG. 4, the Zn concentration increases as the molar ratio of the Zn source gas increases, and differs from one crystal plane to another. It can be seen that the hole concentration is much lower than that of Mg in FIG. 3 corresponding to the result of FIG.

When Zn doping is used to grow the p-type cladding layer 205 in the laser diode shown in FIG. 43, the slope of the layer 205 grown on the (311) B plane is (100) as shown in FIG. The Zn concentration becomes higher than that of the flat portion grown on the surface. As a result, the carrier concentration in the (100) plane part where the stripe structure is formed decreases, and accordingly, the resistance of the stripe structure part of the clad layer 205 on which the main part of the active layer is formed becomes lower. It gets bigger. As a result, the current injected from the lower electrode flows around the stripe portion of the active layer, and the laser oscillation efficiency is significantly reduced.

In general, the results of FIG. 1 show that the problem of the increase in the resistance of the InGaAlP layer in the stripe structure corresponding to the (100) plane is that Mg is replaced by Mg instead of Zn doping.
This shows that the use of doping can be avoided.
FIG. 6 shows the (100) plane and a pair of (3) formed on both sides thereof.
11) InGaAs formed on a mesa structure including B-plane
The Mg concentration distribution and the hole concentration distribution in the IP layer, and the corresponding resistivity distributions are shown. FIG.
It can be understood from the results that the Mg concentration level and the hole concentration level are almost constant irrespective of the crystal plane.

Next, a description will be given of a first embodiment of the present invention in which the current confinement is improved by doping the cladding layer with Mg.

FIG. 7 shows a laser diode according to a first embodiment of the present invention.
It is a figure showing the structure of an iod. Laser according to the present embodiment
The diode has a carrier concentration of about 1 × 1 by Zn, for example.
0 ¹⁹cm^-3On a doped p-type GaAs substrate 301
Be composed. All the GaAs substrates 301 are (100)
It has an upper main surface and a lower main surface consisting of
Has no mesa structure 301a in the longitudinal direction of the laser diode
It is formed to extend in the optical axis direction. However,
Laser diode extends in <011> direction of substrate 301
It is formed so that. All mesa structures are (111)
A pair of slopes 301b composed of side B₁, 301b_TwoBy
The sides are defined and coincide with the longitudinal direction of the laser diode
Stripe surface 301c consisting of a (100) plane extending
including.

On the upper main surface of the substrate 301, n-type GaAs
Current constriction layer 302 is formed with a thickness of about 1 μm,
The stripe surface 301c of the GaAs substrate is exposed on the current confinement layer 302 and extends in the longitudinal direction. The current confinement layer 302 is made of about 5 × 10 ¹⁸ c
Doping is performed at a carrier concentration level of m ⁻³ , and slopes 303b ₁ and 303b ₂ are formed on both sides of the stripe surface 301c. These slopes 303b ₁ and 303b ₂ are equivalent to each other and form a (311) B plane. In other words, a second mesa structure is formed on the first mesa structure so as to share a stripe surface 301c of (100) plane,
In the second mesa structure, inclined surfaces 303b ₁ and 303b ₂ each having a (311) B surface are formed on both sides of the stripe surface 301c. At that time, it can be considered that the substrate 301 and the current confinement layer 302 form the substrate structure 300, and the main part of the laser diode is formed on the substrate structure 300 by the MOCVD method. When an epitaxial layer constituting a main part of a laser diode is grown by MOCVD, trimethylindium (TMI) is used as a source of In and trimethylgallium (TMG) is used as a source of Ga, as is usually performed. , Al is triethylaluminum (TEA). Further, arsine is used as the source of As and phosphine is used as the source of P, and the growth is performed under almost the same conditions as shown in Table 1.

On the substrate structure 300, a buffer layer 303 made of GaAs doped with Zn and / or Mg to a carrier density of 1 × 10 ¹⁸ cm ⁻³ is formed by MOCVD.
It is epitaxially grown to a thickness of about 0.1 to 0.2 μm by the method. In addition, Zn and / or Mg
InGa doped to a carrier concentration of × 10 ¹⁸ cm ^-3
A first intermediate layer 304 of P is epitaxially grown on the buffer layer 303 by MOCVD to a thickness of about 0.1 μm. At this time, the shape of the second mesa structure on the substrate structure 300 is changed to the epitaxial layers 303 and 3.
04, and consequently, the thus grown In
The mesa structure corresponding to the upper main surface is transferred to the GaP layer 304 as well. In other words, the mesa structure transferred to the InGaP layer 304 also has a (100) plane extending in the <011> direction and a pair of (3) formed on both sides thereof.
11) An inclined surface composed of a B surface. Middle layer 3
04 acts like the intermediate layers 110 and 204 to reduce spikes appearing in the valence band and to facilitate carrier flow.

On the layer 304, p, which is a main part of the present embodiment, is formed.
A first cladding layer 305 of type InGaAlP is formed. The layer 305 has a composition (Al _0.7 Ga _0.3 ) _0.5 I
has n _{0. 5,} by MOCVD, is grown to a thickness of about 1 [mu] m. The doping of the layer 305 is performed by TMI, T
Bis (cyclopentadienyl) magnesium is mixed with a source gas composed of EG, TMA and phosphine by setting the flow rate so that the carrier density becomes 1 × 10 ¹⁸ cm ⁻³ according to the relationship shown in FIG. Done. Further, the mesa structure of the substrate structure 300 is also transferred to the upper main surface of the first clad layer 305 thus grown.
In other words, (10)
0) plane and (311) B on both sides
A mesa structure including a slope formed of a surface is formed corresponding to the mesa structure on the substrate and the layer 304.

On the upper main surface of the cladding layer 305, an active layer 306 made of undoped InGaP is formed to a thickness of 0.07 μm. The active layer 306 also has a mesa structure corresponding to the mesa structure of the cladding layer 305 transferred onto the upper main surface. In other words, a mesa structure composed of a stripe surface composed of the (100) plane and a slope composed of the (311) B plane on both sides thereof is transferred to the active layer 306. further,
A second cladding layer 307 made of InGaAlP and doped n-type is formed on the active layer 306 with a thickness of about 1 μm. In this case, doping to n-type is In, Ga,
This is performed by mixing selenium hydride or silane such as monosilane or disilane with the source gas of Al and P, and performing growth under the conditions shown in Table 1. In the structure in which such an active layer is formed on the mesa structure, the (100) plane of the active layer is sandwiched between the right and left sides of the slope of the cladding layer 307.

The thus formed second cladding layer 3
07 is about 1 × 10 ¹⁸ cm ⁻³ by Se or Si.
A second intermediate layer 308 made of n-type InGaP doped to a carrier concentration of about 0.1 μm,
Further, a contact layer 309 made of n-type GaAs doped with a carrier density of about 3 × 10 ¹⁸ cm ⁻³ is formed on the intermediate layer 308 to a thickness of about 1 μm. The second
Is for reducing spikes in the conduction band as in the case of the first intermediate layer 304. Further, upper electrode 310 and lower electrode 311 are formed so as to make ohmic contact with the upper main surface of contact layer 309 and the lower main surface of substrate 301, respectively. The end faces of the laser diode facing each other in the longitudinal direction constitute a reflector, similarly to a normal laser diode.

In the present embodiment, the cladding layer 305 can be uniformly doped irrespective of the crystal plane, thereby solving the problem of divergence of the injection current. further,
By sandwiching the stripe region of the active layer between the left and right sides of the slope of the cladding layer 307, the problem of astigmatism can be solved.

In the apparatus shown in FIG. 7, it is possible to reverse the conductivity type of the epitaxial layer. In this case, an n-type GaAs substrate is used instead of the p-type GaAs substrate 301, and Mg doping is performed on the second cladding layer 307. However, in this case, a considerable delay occurs in the incorporation of Mg into the epitaxial layer. Therefore, a laser diode formed on a p-type substrate has a structure in which an Mg-doped cladding layer is formed and a structure formed on an n-type substrate. There is a substantial difference from the case where a Mg-doped cladding layer is formed in a laser diode. Such Mg
The delay in the incorporation of organic molecules (C ₅ H ₅ ) in the reaction vessel
₂ Mg atoms released from Mg are selectively deposited on the vessel wall made of quartz, and Mg
Is believed to occur after the vessel walls have been coated with Mg.

FIG. 8A shows an apparatus formed on an n-type GaAs substrate.
The doping sequence when introducing by the method D is shown.

Referring to FIG. 8A, the cladding layer 30
7 begins after the undoped InGaP active layer 306 is formed. As can be seen from this figure, the incorporation of Mg into the cladding layer 307 starts after a considerable time has elapsed since the growth of the cladding layer 307 was started. In other words, it means that the cladding layer 307 formed in such a sequence becomes undoped immediately above the active layer 306 unless another doping process is used simultaneously. If the cladding layer 307 is not doped, injection of carriers into the active layer 306 does not occur. To avoid this problem, in the process of FIG. 8A, doping with Zn is also used in order to compensate for the depletion of Mg in the portion of the cladding layer 307 in contact with the active layer. That is, at the same time when the growth of the cladding layer 307 starts, Z
n is mixed with a source gas of Al, Ga, In, P in the form of, for example, dimethylzinc. In this case, the incorporation of Zn is started immediately, and the cladding layer 307 surely becomes p-type. Furthermore, after the time required for Mg to cover the vessel wall of the reaction vessel has elapsed, the supply of Zn is stopped, and the incorporation of Mg into the cladding layer 307 at a substantial concentration level is started.

On the other hand, the process of FIG.
Applies to the case of s substrate. In this case, when the GaAs buffer layer 303 is formed on the p-type substrate structure 300, a step of doping the layer 303 with p-type by introducing Zn is included. Further, supply of Mg is performed while the growth of the layer 303 is still continued, and the GaAs layer 303 is supplied.
Is started by mixing bis (cyclopentadienyl) magnesium with the source gas. At this time, the amount of Mg increases with the growth of the GaAs buffer layer 303, and becomes almost constant when the intermediate layer 304 is grown on the buffer layer 303. Further, the supply of Zn is stopped simultaneously with the start of the growth of the intermediate layer 304. The incorporation of Zn into the epitaxial layer is stopped immediately when the supply of Zn is stopped. Even after the growth of the intermediate layer 304 is stopped, the supply of Mg is continued, and the growth of the first cladding layer 305 is started. As a result of such growth, the hole concentration levels of layers 304 and 305 are substantially constant. When the clad layer 305 has grown to a predetermined thickness, the supply of Mg is stopped, and at the same time, the growth of the undoped active layer 306 in which the source of the epitaxial layer is changed is started. Further, a second cladding layer 307 made of InGaAlP doped with Se or Si is formed on the active layer 306 thus grown.
Is formed.

In the process shown in FIG. 8B, a clear boundary of the conductivity type is formed corresponding to the physical boundary between the first cladding layer 305 and the active layer 306 grown thereon, for example. It can be obtained without using another doping process such as doping the layer 305 with Zn. That is, the process of FIG. 8B corresponding to the structure of FIG. 7 is more preferable than the process in which the conductivity types of the semiconductor substrate and the epitaxial layer formed thereon are reversed. However, this does not deny the usefulness of the process of FIG.

Next, the manufacturing process of the structure of FIG.
This will be described with reference to FIGS. 10A and 10B and FIGS. 10C and 10D.

In the first step of FIG. 9A, the silicon oxide layer forms the upper main surface of the p-type GaAs substrate 301 (10
0) deposited on the surface and then patterned to <01
A silicon oxide stripe mask extending in the 1> direction is formed. Further, the substrate 301 is provided with a silicon oxide stripe mask 21 having the main surface on the substrate formed in this manner.
While being protected by wet etching in a mixed etching solution of H ₂ SO ₄ , H ₂ O ₂ and H ₂ O, <01
A mesa structure 301a having a stripe-shaped (100) surface extending in the 1> direction at the top is formed with a width of about 5 μm. The mesa structure 301a thus formed is (100)
The sides of the stripe surface are defined by a pair of slopes composed of the (111) B surface. On the left and right sides of the mesa structure 301a, upper main surfaces of the GaAs substrate 301 are formed (100).
A plane extends parallel to the top (100) plane of the mesa structure.

Next, in the step of FIG.
The n-type GaAs layer 30 is formed on the structure obtained in the step (A).
2 is the (100) stripe surface of the mesa structure 301a.
Deposited by MOCVD with the mask protected by mask 21
It forms by doing. The mask 21 is made of silicon oxide
GaAs layer on the mask 21 because it is formed
Does not occur. Therefore, the GaAs layer 302 has a mesa structure.
(1) of the GaAs substrate 301 extending on both sides of the structure 301a.
00) deposited on the upper main surface, at which time as shown in FIG.
The main surface of the GaAs layer 302 has a (100) stripe
A slope 303 having a face index of (311) B on both sides of the face
b₁, 303b_TwoIs (111) B of the mesa structure 301a.
It is formed corresponding to the surface. At that time, the slope 303
b₁, 303b _TwoIs second with (100) stripe face
To form a mesa structure.

Next, the silicon oxide mask 21 is removed from the structure obtained in FIG.
The layers are sequentially deposited by the OCVD method. At that time, layers 304,
The deposition of 305 is performed, for example, according to the procedure described with reference to FIG. As a result, a layered semiconductor structure shown in FIGS. 10C and 10D is obtained. After the structure of FIG. 10C is formed, the upper and lower electrodes 310 and 311 are respectively connected to the contact layer 3.
09 on the upper main surface of the substrate 301 and the lower main surface of the substrate 301, and FIG.
The laser diode shown in (D) is completed.

The structure of the current confinement structure described in the first embodiment is also effective when the conductivity type of the epitaxial layer is reversed. More specifically, when an n-type GaAs substrate is used instead of the p-type substrate 301, the conductivity type of each epitaxial layer is inverted, and the growth of the p-type cladding layer 307 is performed in the procedure described with reference to FIG. Done.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS.
However, FIGS. 11A and 11B are diagrams showing the principle of the second embodiment.

FIG. 11A is a diagram showing the concentration levels of Mg and Se during the epitaxial growth of InGaAlP for various crystal planes, where the concentration of Se is (311).
It can be seen that the B surface increases more than the (100) surface. In other words, the Se concentration, and thus the electron concentration, is InG
In the aAlP layer, the value is slightly reduced in the (100) plane than in the (311) B plane. On the other hand, it can be seen that the concentration level of Mg doped simultaneously with Se in the InGaAlP layer and the concentration level of the corresponding hole are almost constant regardless of the crystal plane. Further, in the example of FIG. 11A, the Mg concentration is set higher than the Se concentration in both the (311) B plane and the (100) plane.
As a result, the InGaAlP layer is doped p-type irrespective of the crystal plane, and the resistivity changes according to the crystal plane due to the difference in carrier concentration between the (311) B plane and the (100) plane. More specifically, the hole concentration is lower than on the (311) B plane due to the low electron concentration on the (100) plane.
Is also higher on the ( 100) plane. Therefore, FIG.
By using the principle of (A), the resistance index of the cladding layer is selectively decreased by (100) plane stripe portion of the mesa structure is formed so as to selectively increase at the same time (311) B Slope Becomes possible.

FIG. 11B shows another principle of the second embodiment. In the case of FIG. 11B, Mg and Se are co-doped.
Is set such that the conductivity type of the InGaAlP layer changes depending on the crystal plane. That is, the concentration levels of Mg and Se are set so that InGaAlP becomes n-type at the portion grown on the (311) B plane and p-type at the portion grown on the (100) plane.

FIG. 12 is a cross-sectional view of a laser diode according to a second embodiment of the present invention, in which current confinement is performed using the above principle. 12, the device structure itself is substantially the same as that of FIG. 7, and only the main parts will be described below.

In the apparatus shown in FIG. 12, the first clad layer 30
5 during the growth of Mg and Se, and the Mg concentration level is Se.
Is doped so as to be higher than the concentration level of both the (311) B plane and the (100) plane. For example, M
The concentration levels of g and Se are set in the InGaAlP cladding layer 30.
5 are set as shown in Table 2.

[0062]

[Table 2]

That is, by setting the doping level as shown in Table 2, the resistivity of the cladding layer 305 becomes
As shown by the hatched portion in FIG. 12, the portion grown on the (311) B plane is set to be selectively increased. As a result, the drive current supplied to the electrode 311 becomes n-type GaAs
After being confined by the layer 302, it is injected into the stripe portion of the active layer 306 through the low resistance portion of the cladding layer 305 located immediately above the (100) stripe surface of the mesa structure.
As a result, efficient laser oscillation can be performed.

A modification of the second embodiment is based on the principle of FIG. 11B, and the doping levels of Mg and Se are set as shown in Table 3 below.

[0065]

[Table 3]

[0066] If you use the doping levels of Table 3, Figure 12
The indicated (311) the conductivity type of the B-side portion by portions with diagonal lines selectively can be reversed to thereby clad layer 305
It is possible to block the drive current on the slope portion. As a result, the injected driving current is intensively injected into the stripe surface of the active layer 306 corresponding to the (100) stripe surface of the mesa structure as indicated by the arrow in the figure, and the laser oscillation efficiency is improved. .

In any of the above two modifications, since the current confinement structure is formed in the cladding layer formed immediately above the active layer, there is a problem that the drive current diverges after the current is confined. Is substantially eliminated. In other words, the device of FIG. 12 has higher current confinement efficiency than the device of FIG.

Further, by doping the cladding layer 207 with Se and Zn at the same time, it is possible to form a current confinement structure in the cladding layer 207 as shown by the hatched portion in FIG.

FIGS. 13A and 13B show the principle of such a current confinement structure. FIG.
Similarly, when the GaAlP layer 307 grows on the (100) plane and also on the (311) B plane, n
FIG. 13B shows the case where the conductivity type changes in the crystal plane. In the embodiment of FIG. 15A, the conductivity type is not changed, and only the electron concentration is (3
11) The portion grown on the B plane is lower than that grown on the (100) plane.

When the doping in FIGS. 13A and 13B is used for doping the cladding layer 307, the driving current is applied to the mesa structure region grown on the (100) stripe surface as shown in FIG. It is possible to concentrate the current constriction, and it is possible to improve the current confinement efficiency as compared with the embodiment in which the current confinement structure is formed only in the cladding layer 305. The doping shown in FIG. 13A can be realized using the doping levels shown in Table 4 below. On the other hand, the doping shown in FIG. 13B is realized by the doping levels shown in Table 5.

[0071]

[Table 4]

[0072]

[Table 5]

Next, the cladding layers 305 and 307
The present invention is characterized in that another current confinement structure is embedded.
A third embodiment will be described.

First, the principle of the present embodiment will be described with reference to FIGS. Here, FIG. 14 shows the concentration level of Zn introduced into the GaAs layer grown by the MOCVD method for each crystal plane of the GaAs layer, while FIG. 15 shows the concentration level of Se introduced into the GaAs layer similarly. The crystal plane is shown. From FIG. 14, the Zn concentration is (10
On the other hand, the Se concentration decreases as the crystal plane inclines toward the (111) B plane with respect to the (0) plane, while the Se concentration is (111) B.
It can be seen that it increases as the inclination in the B-plane direction increases. On the other hand, the Zn concentration increases as the inclination in the (111) A plane direction increases, and reaches a maximum at an inclination angle corresponding to the (311) A plane. On the other hand, the Se concentration is (11
1) It monotonically increases as the inclination angle in the A-plane direction increases. As described above, by simultaneously introducing Zn and Se into a GaAs layer grown by MOCVD on a plane including different crystal planes, electronic properties such as resistivity and conductivity type can be changed to crystal planes. Can be changed correspondingly.

FIG. 16 shows G grown by MOCVD.
5 shows a change in conductivity type occurring in the aAs layer. Referring to FIG. 16 , a GaAs layer was grown on the (100) plane,
It can be seen that when both Se and Zn are simultaneously doped at a concentration of about 1 × 10 ¹⁸ cm ⁻³ , a high resistance layer can be obtained.
On the other hand, when the crystal plane on which the GaAs layer is grown is inclined in the (111) B plane direction with respect to the (100) plane, the Zn concentration gradually decreases as the inclination angle increases, and the GaAs layer is doped with n-type. You. Further, when the Se concentration level is set slightly lower than that of Zn, the GaAs layer grows on the (100) plane and becomes excessively p-type due to excessive holes released from Zn, but the inclination angle increases. As the temperature increases, the Zn concentration gradually decreases, and as can be seen from FIG. 16, the conductivity type is inverted at an inclination angle of about 10 degrees.

FIG. 17 shows the structure of a laser diode according to a third embodiment of the present invention in which a current confinement layer is embedded in a cladding layer.

Referring to FIG. 17, the laser diode shown in FIG. 7 or FIG.
It has almost the same configuration as the second laser diode.
Therefore, the same reference numerals are given to the parts described in the previous embodiment, and the description will be omitted.

In this embodiment, a thin film is formed in the cladding layer 305.
GaAs layer 312 is provided so that layer 305
It is divided into a lower part 305a and an upper part 305b. Ga
The As layer 312 has a thickness of about 8 nm and forms a mesa structure.
(100) formed on and parallel to the stripe surface
A first stripe region 312a extending in the
(311) on both sides of region 312a formed on plane B
A pair of slope areas 312b extending parallel to this₁, 31
2b_Twoincluding. The GaAs layer 312 is formed by MOCVD.
The region 312a is grown to a p-type by Zn and Se.
Area 312b ₁, 312b_TwoIs an n-type
Will be The doping of such a layer 312 depends on the concentration of Zn and Se.
This is possible by setting the level as shown in FIG.
You. More specifically, when growing the GaAs layer 312, Ga
Dimethylzinc is added to As growth gas, TEG and arsine
And hydrogenated Se, the Zn concentration level on the (100) plane
About 1 × 10¹⁸cm^-3And the concentration of Se
Bell is also about 5 × 10 on the (100) plane¹⁷cm^-3Nana
Set to As a result, n-type region 312b₁, 3
12b_TwoIs doped n-type and injected into the active layer 306
Block with current. As a result, the efficiency of current confinement is further improved.
Up.

FIG. 18 shows a modification of the third embodiment. In this example, the laser diode has substantially the same structure as that of FIG.
The difference is that the conductivity type of the As substrate is inverted. More specifically, the laser diode is formed with a mesa structure 321a corresponding to the mesa structure 301a of the substrate 301.
17 is formed on a GaAs type substrate, and FIG.
The epitaxial layers 322 to 329 corresponding to the epitaxial layers 302 to 309 are formed similarly except that the conductivity types are inverted. The configuration of the apparatus shown in FIG. 18 is clear from FIG. 17, and a detailed description thereof will be omitted.

In the apparatus shown in FIG. 18, the thin GaAs layer 331 having a thickness of about 8 nm
7 so that the cladding layer 327 is
1 and the second layer 3 above the layer 331.
27b. The layer 331 is simultaneously doped with Zn and Se, and the layer 327 is a p-type region 331a formed on the (100) stripe surface of the mesa structure and n-type regions formed on both sides thereof corresponding to the (311) B surface. Slope part 3
31b ₁ and 331b ₂ . The doping of the GaAs layer 331 is performed in the same manner as in the case of the layer 312, and thus the description is omitted.

FIG. 19 shows another modification of the third embodiment.
Referring to FIG. 19, the laser diode according to the present modification includes an n-type GaAs current blocking layer 342 corresponding to layer 302.
Are formed on a p-type GaAs substrate 341 on which is formed a groove 341 reaching the substrate 341 on the upper main surface of the layer 342.
a is formed. The groove 341a forms a negative mesa structure, and has a stripe-shaped bottom surface 341c having a (100) plane orientation.
Defined by a pair of inclined surfaces 341b _1, 341b ₂ of which is formed on both sides (111) B plane orientation. However, the bottom surface 341c is formed from the exposed surface of the GaAs substrate 341. The stripe surface, as in the previous embodiment, typically has a width of about 5 μm.

On the upper main surface of the layer 342 having the negative mesa structure 341a formed in this manner, a silicon oxide mask 52 is formed except for the mesa structure, and a p-type GaAs layer is deposited in this state. You. See FIG. As a result, the p-type region 343 is formed on the exposed surface of the negative mesa structure 341a.
Is selectively grown, and the grown p-type region 343 corresponds to the first mesa structure 341a, and has a stripe-shaped bottom surface 343a having a (100) plane orientation and (311) B on both sides thereof.
A second mesa structure 341 is formed, characterized by the inclined planes 343b ₁ and 343b ₂ having the plane orientation. p-type GaAs substrate 34
1, n-type GaAs layer 342 and p-type GaAs 343
Forms the substrate structure 340, and the main part of the laser diode is formed on the substrate structure pair 340.

On the substrate structure 340, a thickness of about 0.2
A μm p-type GaAs buffer layer 344 is epitaxially grown in conformity with the shape of the second mesa structure, and a first cladding layer 345 made of p-type InGaAlP is formed on the buffer layer 344 in the second mesa structure. Formed in alignment. The cladding layer 345 is doped with Mg as described in the first embodiment. Alternatively, as described in the second embodiment, doping may be performed simultaneously with Mg and Se.

On the upper main surface of the cladding layer 345, Zn and S
In the current blocking layer 346 made of GaAs doped by introducing e simultaneously, the portion grown on the (100) plane is doped p-type, and the portion grown on the (311) B plane is doped n-type. It is formed as follows. Furthermore, p
A second cladding layer 347 of type InGaAlP is grown on the current blocking layer 346. Furthermore, undoped InG
An active layer 348 made of aP is formed on the cladding layer 347. The n-type cladding layer 34 is formed on the active layer 348.
20 is grown, and a contact layer 350 made of n-type GaAs is formed on the cladding layer 349.
The structure shown in (B) is obtained. The above-described epitaxial growth process can be performed using a well-known MOCVD method. After the layered structure of FIG. 20B is formed, the upper electrode 351 and the lower electrode 352 are formed on the upper main surface of the contact layer 350 and the lower main surface of the substrate 341 respectively, and the structure of FIG. 19 is obtained.

Also in this embodiment, p-type InGaAlP
The Mg and Se concentration levels of the cladding layers 345 and 347 are doped p-type in the region where the cladding layers are grown on the (100) stripe surface of the mesa structure, and (311)
The region grown on the B-plane may be set to be doped n-type. Alternatively, the cladding layers 345 and 347 may be uniformly doped with Mg. In any of these cases, a GaAs layer 346 is formed in the cladding layer, and (3)
11) By blocking the drive current by the n-type region grown on the B plane, it is possible to obtain an effective current confinement effect.

Next, a fourth embodiment of the present invention will be described. Before describing the embodiment, the principle of the present embodiment will be described with reference to FIG.

FIG. 21 is a diagram showing the relationship between the carrier concentration and the crystal plane in an InGaAlP layer simultaneously doped with Zn and Se. In the figure, the filled circles indicate the concentration level of the electrons emitted by Se as a function of the tilt angle of the crystal plane in the direction of the (111) A plane, while the open circles indicate the concentration level of the holes emitted from Zn. It is shown as a function of the plane tilt angle. The black and white triangles are InG
FIG. 9 shows a change in the electron concentration level and a change in the hole concentration level when the aAlP layer is simultaneously doped with Zn and Se.
As can be seen from FIG. 21, the epitaxial layer (10
When grown on the (0) plane, the concentration of electrons emitted from Se exceeds the concentration of holes emitted from Zn, but the epitaxial layer has a (411) A plane or a ( 31 ) plane.
1) When grown on the A-plane, this relationship is reversed to match the relationship of FIGS. More specifically , (41
1) The epitaxial layer grown on the A-plane or ( 311) A-plane is doped p-type, while the (100)
The epitaxial layer grown on the surface is doped n-type. In the example of FIG. 21, about 1 × 10 ¹⁸ on the (100) plane
An electron concentration level of about 6 × 10 ¹⁶ cm ⁻³ is obtained on the (311) A plane under the same conditions, while an electron concentration level of cm ^{−3 and} a hole concentration level of 2 × 10 ¹⁶ cm ⁻³ are obtained. And a hole concentration level of about 1 × 10 ¹⁸ cm ⁻³ .

As described above, the relationship of FIG.
This is useful for controlling the conductivity type of the P layer based on the crystal plane on which the layer is grown. That is, the principle of FIG. 21 simply sets the extending direction of the (100) plane stripe plane to <01-
By setting the 1> direction and setting the slope of the mesa structure to the (311) A plane instead of the (311) B plane, it can be applied to any of the above-described embodiments. (311) A
Since the change width of the carrier concentration is larger when the plane is used than when the (311) B plane is used, a more effective current confining action can be obtained. The embodiment described below is characterized by utilizing such a large change in carrier concentration.

FIG. 22A shows a first setting example of the concentrations of Zn and Se. In this example, the concentration levels of Zn and Se are set so that the conductivity type does not change between the epitaxial layer part grown on the (100) plane and the epitaxial layer part grown on the (311) A plane. . Even in this case, the carrier concentration level and the resistivity are substantially increased in the portion of the epitaxial layer grown on the (100) plane. Therefore, the doping of FIG. It is possible to narrow the current.

On the other hand, in FIG. 22B, Zn and S
e concentration level is (100) in the InGaAlP layer.
The value is set such that the conductivity type changes between the portion grown on the surface and the portion grown on the (311) A surface. In this case, the concentration of Se exceeds the concentration of Zn in the portion grown on the (100) plane, while this relationship is reversed in the portion grown on the (311) A plane.

Next, a laser diode according to a fifth embodiment of the present invention will be described with reference to FIG.

[0092] Referring to FIG. 23, the laser diode of this embodiment will be formed on the p-type GaAs substrate 401, a mesa structure 401a corresponding to the main support structure 301a of FIG. 12 is formed on a substrate 401 ing. That is, the mesa structure 401a extends in the <01-1> direction (10
0) Stripe plane 401c with plane orientation, and slopes 401b ₁ and 401b ₂ with (311) A plane orientation extending on both sides of the stripe plane 401c.
It is defined, on the substrate 401 to correspond to the server <br/> Ffa layer 3 03 of FIG. 12 is formed the buffer layer 402 by a. Furthermore, the intermediate layer 403 corresponding to the tier 304 in Figure 12 is formed on the buffer layer 402. Middle layer 4
On 03, it is clad layer 404 corresponding to the clad layer 305 of FIG. 12 to form a Mg as a dopant, so that the cladding layer 404 is uniformly doped p-type.

On the upper main surface of the cladding layer 404, an undoped active layer 405 is epitaxially grown as in the previous embodiment, and a first cladding layer 406 made of n-type InGaAlP is formed on the active layer 405. It is formed. The cladding layer 406 is doped with Se so that any portion becomes n-type. Further, on the cladding layer 406, n
Another cladding layer 407 of type InGaAlP doped simultaneously with Zn and Se is grown by MOCVD. At this time, the concentrations of Zn and Se are set as shown in FIG. 22 (A) or (B), and as a result, the cladding layer 407 has a slope portion 40 grown on the (311) A plane.
The resistivity increases at 7b ₁ and 407b ₂ . Alternatively, in the case of FIG. 22B, the regions 407b ₁ , 40
Shows a p-type conductivity in 7b _2.

On the cladding layer 407, there is shown a diagram of the previous embodiment .
N-type intermediate layer 408 made of InGaP which corresponds to the tier 308 of the 12 is grown, the current blocking layer 409 made of p-type GaAs is grown on the intermediate layer 408. further,
The layer 409 is patterned so that the intermediate layer 408 is exposed at the mesa structure, and the n-type GaAs contact layer 41 is patterned.
Zero is deposited on the current blocking layer 409 so as to contact the exposed surface of the intermediate layer 408. Further, upper and lower electrodes 411 and 412 are formed so as to make ohmic contact with the upper main surface of layer 410 and the lower main surface of substrate 401, respectively.

In the laser diode of FIG.
In addition to the current confinement effect of the As layer 409, the p-type regions 407b ₁ and 407 formed in the n-type cladding layer 407
current confinement effect by b ₂ is obtained. As a result, it is possible to improve the efficiency of laser oscillation. The intermediate layer 408 is also co-doped with Zn and Se, and the layer 408 is made of a first region 408a having a low resistivity and a pair of first regions 408a having a large resistivity, as in the case of FIG. The second region 408b ₁ and the second region 408b ₂ can also be formed separately. Further, when the intermediate layer 408 is doped, FIG.
In response to (B), the region 408a has an n-type
8b ₁ and 408b ₂ may be formed in a p-type.

FIG. 24 shows an example in which an n-type substrate 421 is used instead of the p-type substrate 401. The substrate 421 has (10
0) The stripe surface 421a having the plane orientation and (11) on both sides thereof
1) mesa structure 421a defined by the inclined surfaces 421b _1, 421b ₂ of the A plane orientation is formed, further p-type Ga
An As layer 422 is formed on the substrate 421 in the same manner as the layer 322 in FIG.

As in the case of the layer 322, the p-type GaAs layer 422 has a (100) plane stripe and (3)
11) A second mesa structure composed of slopes 423b ₁ and 423b _{2 having} A-plane orientation is formed, and n-type GaAs is further formed.
A buffer layer 423 is grown on layer 422.
The on the buffer layer 423 is grown intermediate layer 424 made of n-type InGaAlP, first cladding layer 425 ₁ is grown on the intermediate layer 424, further composed of n-type InGaAlP. Layer 425 ₁ is doped simultaneously with Zn and Se, and has a first region 425a grown on the (100) plane;
It includes a pair of second regions 425b ₁ and 425b ₂ grown on the (311) A plane on both sides of the first region 425a.

As described with reference to FIG. 22A, the carrier concentration in the regions 425b ₁ and 425b ₂ can be selectively reduced by appropriately setting the doping concentrations of Zn and Se. FIG. 22 (B)
By setting the doping concentrations of Zn and Se as shown in ( ₁₎ , the conductivity type of the regions 425b ₁ and 425b ₂ can be selectively set to p-type.

[0099] Further, another cladding layer of InGaAlP which is Se doped on the cladding layer 425 ₁ 425
₂ and an active layer 42 of undoped InGaP
6 on the layer 425 ₂ is formed in a shape matching the mesa structure. On the active layer 406, a cladding layer 427 made of p-type InGaAlP is epitaxially grown.
The intermediate layer 428 made of InGaP is a clad layer 427.
A contact layer 429, formed of p-type GaAs, is grown on layer 428 as usual. After the layered semiconductor structure is thus formed, the upper electrode 4
30 is deposited on the upper main surface of the p-type GaAs contact layer, and a lower electrode 431 is formed on the lower main surface of the n-type GaAs substrate 421.
Is formed.

According to this embodiment, the injected carriers can be effectively narrowed by the regions 425b ₁ and 425b ₂ . The effect of such current confinement is that Z
It can be further increased by performing simultaneous doping of n and Se.

FIG. 25 shows another modification of the fourth embodiment.
In this modification, the laser diode is an n-type GaAs substrate 4
41, and p-type GaAs is formed on the upper surface of the substrate 441.
The layer 442 on which the current constriction layer 442 is formed and the substrate 441 have a negative mesa structure 441a formed similarly to the mesa structure 341a of FIG.
An intermediate layer 443 is formed on the layer 442 so as to cover the mesa structure 441a.

[0102] On the intermediate layer 443 is first cladding layer 444 ₁ is epitaxially grown of n-type InGaAlP, so that when the cladding layer 444 ₁ are shown in FIG. 22 (A) or FIG. 22 (B), Zn And Se at the same time. With the relationship shown in FIG.
And when Se is doped, low-resistance region 444a of the cladding layer 444 ₁ (100) grown n-type on the surface
When a pair of n-type high resistance region grown on the mesa structure (311) A plane 444b _1, it made 444b ₂ Togae, cladding layer 444 ₁ acts as an effective current confinement structure.
On the other hand, when Zn and Se are doped according to the relationship shown in FIG. 22B, the region 444a is doped n-type, while the regions 444b ₁ and 444b ₂ are doped p-type.
Therefore, the regions 444b ₁ and 444b ₂ form a current blocking structure that acts as an effective current confinement structure.

Clad layer 444₁On top is n-type InGaAs
Another cladding layer 444 of IP _TwoIs epitaxial
The grown active layer 445 made of undoped InGaP
Layer 444_TwoGrow on. Furthermore, p-type InGaAl
The cladding layer 446 made of P is on the upper main surface of the active layer 445.
And an intermediate layer 447 made of p-type InGaP
Grown on 446. On top of layer 446 is a further p-type
A tact layer 448 is formed as shown. Furthermore, on
The part electrode 451 and the lower electrode 452 form a contact layer 448
Formed on the upper main surface of the substrate and the lower main surface of the substrate 441, respectively.
It is.

FIG. 26 shows another modification of the fourth embodiment.
The laser diode of the present modification has a GaAs substrate 441 and a GaAs layer 44 shown in FIG.
2, a negative mesa structure similar to the mesa structure 441a is formed on the substrate structure 441 '.

[0105] On the substrate 441 'is epitaxial layer corresponding to each d Pitaki <br/> interstitial layer in FIG. 25 443'～44
8 'are sequentially formed with the opposite conductivity type. That is, the epitaxial layer 443 'corresponds to the epitaxial layer 443, and the epitaxial layer 444'
4, epitaxial layer 445 'corresponds to epitaxial layer 445, epitaxial layer 446' corresponds to epitaxial layer 446, and epitaxial layer 44
7 ′ corresponds to the epitaxial layer 447, the epitaxial layer 448 ′ corresponds to the epitaxial layer 448, and the epitaxial 449 ′ corresponds to the epitaxial layer 449. However, the layers 445, 44 constituting the undoped active layer
Except for 5 ', the conductivity types are reversed. In addition, layer 4
The configuration of 44 'is different in that it is composed of a single layer of p-type InGaAlP. Similarly, the configuration of layer 446 '
Two layers 6 ', that is different in terms of the layer of the lower layer 446 ₁ and the upper layer 446 _2.

Layer 446 ₁ is uniformly doped n-type by doping Se, whereas layer 446 ₂ is doped n-type by doping Zn and Se simultaneously. Further, the concentration levels of Zn and Se are shown in FIG.
By appropriately setting according to the principle of (A), the layer 4
46 ₂ Slope 446 growing on (311) A-plane
a, 446b can be selectively increased with respect to the stripe region 446c grown on the (100) plane stripe surface. Alternatively, the conductivity type can be selectively inverted in the regions 446a and 446b by setting the doping level of Zn in accordance with the relationship of Se in FIG. With any of these methods, the injection current can be confined to the mesa structure 441a, and efficient laser oscillation becomes possible.

Next, a fifth embodiment of the present invention will be described with reference to the laser diode of FIG. 27 having a configuration similar to that of FIG. In FIG. 27, portions corresponding to FIG. 25 are denoted by the same reference numerals, and description thereof will be omitted.

[0108] Referring to FIG 27, the cladding layer 406 is constituted by a lower layer 406 ₁ and the upper layer 406 _2, the upper layer 406 ₂ is doped uniformly n-type by introducing a Se respect, the lower layer 406 ₁ is Zn and S
Simultaneous doping of e, the first region 61a of the n-type layer 406 in _1, second region 61b _1, 61b of p-type on both sides
It is characterized by being formed so as to be sandwiched by _two . As a result, n-type upper layer 406 ₂ and the area 61b _1, 61b ₂
A pn junction is formed between the pn junction and the pn junction, and the pn junction forms a remote junction that acts as a barrier to carriers injected into the active layer 405. That is,
(311) The drive current flowing through the A surface is blocked by the remote junction, and the efficiency of current confinement is further improved.

FIG. 28 shows a modification of the fifth embodiment.
It has almost the same configuration as the laser diode No. 4.
However, the cladding layer 425 ₂ is constituted by a lower layer 425 ₂₁ doped n-type with Se and an upper layer 425 ₂₂ doped simultaneously with Zn and Se.
Reference numeral 5 ₂₂ denotes a first region 425 ₂₂ a corresponding to a mesa structure stripe surface having a (100) plane orientation and doped n-type, and a region 4
A pair of p-type regions 425 ₂₂ b ₁ and 425 ₂₂ b ₂ formed on both sides of 25 ₂₂ a corresponding to the (311) A plane,
n-type layer 425 ₁₂ and region 425 ₂₂ b ₁ or 425 ₂₂ b
_A remote junction is formed between the _two . As a result, (3
11) The driving current flowing through the A surface is blocked by the potential barrier associated with the remote junction, and the driving current is reduced to the region 425.
it is possible to perform current confinement to flow a and 425 ₂₂ a.

FIG. 29 shows another modification of the fifth embodiment.
In this example, the laser diode is substantially similar to that of FIG.
, But the cladding layer 444_TwoIs n by Se
Mold doped lower layer 444_{twenty one}And Zn and Se
When doped top layer 444 _{twenty two}And formed. Further
The upper layer 444_{twenty two}Is a (100) stripe with a mesa structure
N-type doped first region 444 corresponding to the surface_{twenty two}a and
(311) A pair of p-type doped regions corresponding to the A-plane
444_{twenty two}b₁And 444_{twenty two}b_TwoAnd the layer 444_{twenty one}When
Region 444_{twenty two}b₁Or 444_{twenty two}b_TwoLimo between
A junction is formed. Current blocking action by remote junction
As a result, the driving current is reduced to the region 444a and the (100)
Current constriction so that it flows through the
receive.

Next, a sixth embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 30, the laser diode according to the present embodiment is formed on an n-type GaAs substrate 461. The substrate 461 has a stripe surface 4 having a (100) orientation.
61c and a pair of slopes 4 of (311) A plane orientation on both sides thereof
A negative mesa structure defined by 61b ₁ and 461b ₂ is formed, and the buffer layer 4 made of n-type GaAs is formed.
62 is epitaxially grown on such a substrate. At this time, the buffer layer 462 has the second mesa structure as the mesa structure 4
61a. The second mesa structure also forms a negative mesa, and is composed of a stripe surface having a (100) plane orientation and slopes having a (311) A plane orientation on both sides thereof.

On the buffer layer 462, n-type InGaAs
A cladding layer 463 made of 1P is grown by simultaneously doping Zn and Se, and a pair of p-type regions 463b ₁ and 463b ₂ are formed in the cladding layer 463 so as to correspond to the (311) A plane. Other portions of layer 463 are n-type doped. Further, an active layer 464 made of undoped InGaP is epitaxially grown on the cladding layer 463, and a p-type cladding layer 465 made of InGaAlP is further grown on the active layer 464.

In the cladding layer 465, a Kiyono mesa structure 465a projecting upward is formed at a position corresponding to the negative mesa 461a, and an intermediate layer 466 made of p-type InGaP is formed corresponding to the mesa structure 465a. Furthermore, p-type Ga
Another intermediate layer 467 of As is formed on layer 466 as an extension of mesa structure 465a.

The mesa structure 465a includes an InGaP layer 466 and a GaAs layer 467 grown on the InGaP layer 466, and an n-type GaAs region 468 having a current confinement function is formed on the left and right. Furthermore, a contact layer 469 made of p-type GaAs
Is grown on layer 468 such that it contacts the upper major surface of layer 467.

In the laser diode according to the present embodiment, the current confinement effect can be obtained in the p-type regions 463b ₁ and 463b ₂ in addition to the normally used n-type GaAs layer 468, and the current confinement effect is further enhanced. be able to.

Next, the step of forming the structure of FIG. 30 will be described with reference to FIG.
1 (A) to (D), FIGS. 32 (E) to (G), FIG.
(H) to (J) and FIGS. 34 (K) to (M).

Referring to FIG. 31A, an n-type substrate 46 is formed.
1, a mesa structure 461a is formed as a groove extending in the <01-1> direction. The groove thus formed is a bottom surface 461c and a pair of slopes 461 on both sides thereof.
defined by the b _1, 461b _2. Furthermore, n-type G
The substrate 461 in which the aAs layer 462 is thus formed with the grooves
Epitaxially grown thereon, and as a result, the layer 462 also has a second (311) A-plane oriented second slope defined by a pair of slopes.
31 corresponds to the first mesa structure shown in FIG.
It is formed as shown in FIG.

Next, the MOCV is added to the structure shown in FIG.
Layers 463 to 467 are sequentially formed with the respective conductivity types by Method D, and the structure in FIG. 31C is obtained. FIG.
In (C), layer 463 is n-doped except for the p-doped slope, while layers 465-467 are n-doped.
Doped in the mold.

Next, a silicon oxide mask 471 is formed as shown in FIG.
(D), and a photoresist 471 is deposited on the mask 471. A concave portion or a groove is formed on the upper main surface of the layer 467 and on the upper main surface of the layer 471 corresponding to the mesa structure 461c, and the photoresist is formed so as to fill the concave portion.

In the step of FIG. 32E, the photoresist 4
Ashing 72 is performed in oxygen plasma to remove the grooves except for the grooves.

Next, the silicon oxide layer 471 is etched using the resist 472 remaining in the step of FIG. 32F as a mask. After the etching, the photoresist is removed in the step of FIG.

Further, the structure formed in the step of FIG. 32 (G) is etched with an etching solution composed of an aqueous solution of NH ₄ and H ₂ O ₂ to form a layer 467 as shown in FIG.
Is selectively removed. Further, the silicon oxide layer 471 extending upward on both sides of the layer 467 thus patterned is removed by etching using a buffered HF solution in the step of FIG.

Further, using the patterned layer 467 as a mask, the intermediate layer 466 is formed of Br, HBr and H
Etch away with a mixture of ₂ O, then add layer 46
5 was etched with an etching solution containing HCl to obtain FIG.
The structure shown in (I) is obtained.

Next, using the silicon oxide layer 471 as a mask, an n-type GaAs layer 468 is deposited by MOCVD to obtain the structure shown in FIG. FIG. 34 (K)
After the structure shown in FIG.
(L), and removed in the step of FIG.
By depositing the type GaAs layer 469, the structure of FIG. 30 is obtained.

Next, a seventh embodiment of the present invention will be described.

FIG. 35 shows a stripe laser diode according to the seventh embodiment. The laser diode shown is G doped with Si to a carrier concentration of 4 × 10 ¹⁸ cm ^−3.
It is formed on an aAs substrate 501 and has an upper main surface having a normal (100) plane orientation. Further, a step 501a extending in the <01-1> direction is formed on the main surface on the substrate,
The step 501a extends in the <01-1> direction (31
1) It is formed by a stripe surface 501c having an A-plane orientation and has a height of about 1 μm. That is, the step 501
a shows the upper main surface of the substrate 501 in the first (100) plane region 5.
01b ₁ and is divided into a second (100) plane regions 501b _2. Such a step can be formed, for example, by forming a silicon oxide mask on the (100) plane of the GaAs substrate and performing etching using an HF aqueous solution.

On the upper main surface of the substrate 501, an n-type buffer layer 502 doped with Se or Si is about 1 μm.
m. When Se is used as a dopant, the concentration level of Se is as described above with reference to FIG.
It changes depending on the crystal plane. In the example shown, the Se concentration of about 3 × 10 ¹⁷ cm ⁻³ is obtained in the part grown on the (100) plane, but about 1.2 × 10 ¹⁷ cm in the part grown on the (311) A plane. cm ^-3 . See the relationship in FIG. Since the epitaxial growth is performed with a uniform thickness, the substrate 5
The step shape of the upper main surface 01 is transferred to the upper main surface of the buffer layer 502.

On the buffer layer 502, an n-type InGaP
An intermediate layer 503 is epitaxially grown by MOCVD. The layer 503 has a composition of Ga _0.5 In
_It has _0.5 P and is doped with Se or Si. Se
When Se is used, the Se concentration changes depending on the crystal plane, and (1)
00) 3.7 × 10 ¹⁷ cm ^-3 at the portion grown on the surface,
(311) The density of 7 × 10 ¹⁶ cm ⁻³ is obtained at the portion grown on the A-plane. The thickness of the layer 503 is 0.1 μm on the (100) plane and 0.25 μm on the (311) A plane.

[0130] On layer 503 is doped with Se or Si, composition _{(Al 0.7 Ga 0. 3) 0.5} In 0.5 P
The cladding layer 504 made of n-type InGaAlP is formed. The thickness of layer 504 varies slightly in the crystal plane,
0.3 μm at the portion grown on the (100) plane, (31
1) The portion grown on the A-plane has a thickness of 0.6 μm. Furthermore, a composition (Al) made of n-type InGaAlP
_0.4 Ga _0.6 ) The light guide layer 505 having _0.5P is a layer 5
04 is formed. Layer 504 is doped n-type with Si or Se and has a thickness of 0.2 μm on the portion grown on the (100) plane and a thickness of 0.4 μm on the portion grown on the (311) A. . On the layer 505, an undoped InGaP active layer 50 having a composition of Ga _0.5 In _0.5 P
6 are formed. The thickness of the active layer 506 also depends on the crystal plane on which it is grown. The thickness of the active layer 506 is 0.015 μm on the (100) plane and 0.03 μm on the (311) A plane. Having

On the active layer 506, the composition is (Al _0.7 G
a _0.3 ) _0.5 In _0.5 P p-type InGaAlP cladding layer 507 is grown. The layer 507 is doped with Mg or Zn, and a portion grown on the (100) plane has a thickness of 0.3%.
It has a thickness of 0.6 μm and a thickness of 0.6 μm at the portion grown on the (311) A plane. Further, another cladding layer 508 made of InGaAlP and simultaneously doped with Zn and Se is formed on the layer 507. The cladding layer 508 has a composition (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, and has a 0.4 μm-thick p-type region 508 a and n-type regions 508 _{b 1} , 508 _{b 2} having a thickness of 0.2 μm on both sides thereof. including.
However, in the region 508a, the concentration of Zn is higher than Se, so that the region 508a is p-type, whereas the region 508b ₁ , 5
Higher n than that of Zn concentration towards the concentration of 08b ₂ in Se
Indicates mold conductivity.

On the layer 508, the composition is (Al _0.1 Ga
_0.9 ) p-type InGaAl represented by _0.5 In _0.5 P
An intermediate layer 509 made of P is formed with a thickness of 0.04 μm on the portion grown on the (100) plane and with a thickness of 0.08 μm on the portion grown on the (311) A plane. . Further, the composition is (Al _0.4 Ga _0.6 ) _0.5 In _0.5
Another intermediate layer 510 made of p-type InGaAlP of P
It is formed on layer 509 to have a thickness of 0.1 microns on the (100) plane and 0.2 microns on the (311) A plane. Layers 509 and 51
0 is doped with Mg or Zn, and indicates p-type conductivity irrespective of the crystal plane. Furthermore, p-type GaAs
A contact layer 511 is formed with a thickness of 5 to 10 microns. The layer 511 is made of Zn and is 1 to 6 × 10 ^18.
It is doped at a concentration level of cm ^-3 .

Each epitaxial layer is grown by mixing a gaseous source material containing a desired dopant into an epitaxial source gas, as in the previous embodiment. That is, when only Se is introduced into the layers 502 to 505, selenium hydride is set so that the molar concentration of Se is about 2 × 10 ⁻⁶ with respect to the molar concentration of other group V elements. As a result, an electron concentration level of about 8 × 10 ¹⁷ cm ⁻³ is obtained in the portion grown on the (100) plane, and about 1.5 × 10 ¹⁷ c 3 in the part grown on the (311) A plane.
An electron concentration level of m ^-3 is obtained. On the other hand, in the layer 508 in which Se and Zn are simultaneously doped, the molar ratio of dimethylzinc is set to 0.1 with respect to the gaseous source material of the group III element when supplying Zn. That is, dimethyl zinc is added so that the Zn concentration in the layer 508 is about 5 × 10 ¹⁶ cm ⁻³ in the portion grown on the (100) plane, and (311)
Supplied so as to be about 5 × 10 ¹⁷ cm ⁻³ at the portion grown on the A-plane.

After the layered structure shown in FIG. 35 is formed, upper electrode 512 and lower electrode 513 are formed on the upper main surface of GaAs contact layer 511 and the lower main surface of substrate 501, respectively.

In the laser diode of FIG. 35 as well, a current constriction effect is obtained in the region 508a.
(311) Efficient laser oscillation occurs in the stripe region formed corresponding to the A-plane. The element structure of FIG. 35 can be formed by repeating a simple epitaxial process after the step 501a is formed on the substrate 501.

FIG. 36 shows a modification of the apparatus shown in FIG.
Remote junction formed in the lad layer 507
It is characterized by. Layer 507 is the lower layer 507₁And upper layer 50
7_TwoFormed by the layer 507₁Is on the (311) A side
The corresponding p-type first region 507a and both are n-type
A pair of doped second regions 507b₁, 507b _Two
Formed. Such a layer 507₁Doping first
This can be achieved by simultaneous doping of Se and Zn as described. This
In contrast, the upper layer 507_TwoAre uniformly p-type doped.
As a result, n-type region 507b₁Or 507b_TwoAnd p
Mold upper layer 507 _TwoA remote junction is formed at the interface of
The current constriction effect can be further increased.

FIG. 37 shows another modification of the laser diode of FIG. The laser diode according to the present modification uses an n-type GaAs substrate 601 whose upper main surface 601b is inclined by about + 8 ° in the (111) A plane direction with respect to the (100) plane. Here, a positive tilt angle indicates a clockwise tilt. Further, the substrate 601 extends in the <01-1> direction.
Rume support structure 601a is formed, the mesa structure 601
a is defined by a side wall surface 601c having a (311) A plane orientation and another side wall surface 601d formed so as to be opposed thereto and inclined at an angle of -9 ° from the (100) plane to the (111) A plane direction. ing. As a result, the surface 601d is
Constitutes a plane which is crystallographically equivalent to the main surface 601b.

[0138] On the substrate 601 thus formed, an epitaxial layer 602-606 are sequentially deposited, of which the layer 602 corresponds to the clad layer 502 of FIG. 35, the layer 603 is active layer of FIG. 35 The layer 604 corresponds to FIG.
Corresponds to clad layer 507 of 35, the layer 605 of FIG. 35
Corresponds to clad layer 508, a layer 50 of the layer 606 is 35
9 corresponds. Further, a contact layer 607 made of p-type GaAs is formed on layer 606 in response to co Ntakuto layer 511 in FIG. 35. An upper electrode 608 is formed on the upper main surface of the layer 607, and a lower electrode 609 is formed on the lower main surface of the substrate 601. Here, layer 602 is doped n-type with Se or S, while layers 604 and 606 are p-type doped with Mg or Zn. On the other hand, the cladding layer 605 is simultaneously doped with Zn and Se.

In the laser diode of FIG. 37, the cladding layer 605 is simultaneously doped with Zn and Se. As a result, as in the case of the previous embodiment, three different portions, that is, a stripe plane having the (311) A plane orientation are formed. First area 6 including
05a and a second region 605b including the slope portions on both sides thereof
₁ , 605b ₂ , where the first region 60
5a is doped p-type while the second region 605
b ₁ and 605b ₂ are doped n-type. However, the region 605b ₁ that forms the sidewalls of the mesa 601a, by the substrate on the principal surface is sloped to form a crystal plane 605b ₂ equivalent to the surface to be formed on the substrate on the principal surface.
As a result, in the layer 605, only the side wall surface 605a is doped p-type, and all other portions of the layer 605 are doped n-type. Therefore, the driving current is (31) in the active layer 603.
1) The laser beam intensively flows in the portion formed on the surface A, and laser oscillation is intensively generated in such a stripe portion.
Since no drive current is supplied to other portions of the active layer, laser oscillation does not occur.

By applying the principle of the laser diode shown in FIG. 37, the problem of melting at the end face of a laser diode known as COD can be solved. When COD occurs, the impurity level at the end face of the laser diode causes absorption of the light beam, and such absorption causes a rise in the temperature of the end face due to heat generation. When the temperature of the end face rises, the band gap of the active layer becomes narrow, and ultimately a short circuit occurs.

In order to avoid the COD problem, the conventional high-power laser diode uses a material having a large band gap only at the end face, or devises an electrode shape so that no current is injected into the end face. However, these countermeasures are all complicated, and it has been difficult to apply them to an actual laser diode manufacturing process.

FIGS. 38 and 39 are views for explaining a method of manufacturing a laser diode in which the problem of COD is solved based on the principle of FIG.

Referring to FIG. 38, n-type GaAs substrate 7
01 from the (100) plane to the (11)
1) It is formed so as to be inclined + 8 ° to the A plane. Further, the upper surface of the substrate is covered with a silicon oxide layer 702, which is patterned as shown in FIG. At this time, the oxide layer 702 forms a mask, and protrusions 702a and 702b are formed at both ends of the substrate 701 corresponding to both ends of the laser diode.

Next, the substrate 701 protected by the mask 702
Is processed by wet etching. Etching is based
Acting on the exposed portion of the upper main surface of the plate 701, the structure shown in FIG.
can get. Here, FIG. 39 shows a state where the mask 702 is removed.
State. As is clear from FIG.
When the main surface is in the form of a stripe having the (311) A plane orientation, 1
Surface 703a and both sides of the stripe surface 703a.
Pair of flat portions 703b₁, 703b_TwoDivided into
You. Further, the (311) A surface is provided on both end surfaces of the substrate 701.
The slope 704a that is inclined with respect to the stripe surface 703a
It is formed in alignment with the extending direction. However, the slope 704
a on both sides of the upper main surface 703b of the substrate 701 ₁Or 7
03b_TwoSurface 704b with the same surface index as₁, 704b_TwoIs shaped
Has been established.

On the substrate 701, the MOCVD method is used.
An epitaxial layer is grown as in FIG. In this embodiment, an epitaxial layer grown on the stripe surface 703a is not equivalent to an epitaxial layer grown on the stripe surface 704, the relationship between these layers and the relationship of the layer 605a and the layer 605b ₁ in the laser diode of FIG. 37 It will be the same.

FIG. 40 shows a main part of a laser diode formed on the structure of FIG. 39, and includes an n-type InGaAlP cladding layer 705a and an undoped InGaP active layer 706a.
When, and a p-type InGaAlP cladding layer 707a, each surface 703a, is grown on 703b _1, 703b _2. The cladding layer 705 is simultaneously doped with Se and Zn and has an n-type irrespective of the crystal plane, whereas (311) A
In the layer 707a grown on the surface, only the portion grown on the (311) A surface is doped p-type, and the other portions are doped n-type.

On the other hand, epitaxial 705b to 707b
Are surfaces 704a, 704 formed at both ends of FIG.
b _1, epitaxial corresponding to 704b ₂ 705a~
It is grown simultaneously with 707a. However, none of these crystal planes includes the (311) A plane. Therefore, the cladding layers 705b and 707b are both n-type doped, and therefore, the junctions constituting the double heterostructure laser diode are not formed at both ends of the laser diode. Therefore, even if the electrodes are uniformly formed above and below the laser diode, laser oscillation does not occur at both ends of the laser diode, and the problem of COD can be avoided.

The present invention is not limited to the above embodiments, and various modifications and changes can be made without departing from the spirit of the invention.

[0149]

According to the present invention, by using Mg as a p-type dopant, the resistivity of a cladding layer grown by MOCVD can be set uniformly irrespective of the crystal plane, and it is made of Mg or Zn. p-type dopant and S
By simultaneously doping the cladding layer with an n-type dopant consisting of e, the resistivity or conductivity type of the cladding layer can be selectively reduced or inverted in accordance with the stripe region of the laser diode, whereby It becomes possible to efficiently narrow the drive current injected into the laser diode.

[Brief description of the drawings]

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

FIG. 2 is another diagram illustrating the principle of the present invention.

FIG. 3 is a diagram showing a relationship between a molar ratio of a Mg dopant gas and a hole concentration.

FIG. 4 is a diagram showing a relationship between a molar ratio of a Zn dopant gas, a hole concentration, and a Zn concentration.

FIG. 5 is a diagram showing the relationship between each crystal plane, Zn concentration, hole concentration, and resistivity.

FIG. 6 is a diagram showing the relationship between each crystal plane, Mg concentration, hole concentration, and resistivity.

FIG. 7 is a perspective view illustrating a structure of a laser diode according to a first embodiment of the present invention.

FIGS. 8A and 8B are diagrams showing a growth sequence of each epitaxial layer when manufacturing the laser diode of FIG. 7;

FIGS. 9A and 9B are process diagrams (part 1) for manufacturing the laser diode of FIG. 7;

FIGS. 10C and 10D are process diagrams (part 2) for manufacturing the laser diode of FIG. 7;

11 (A) and (B) are each crystal plane, Mg concentration, S
FIG. 4 is a diagram showing a relationship among e concentration, hole concentration, and resistivity.

FIG. 12 is a diagram showing a second embodiment of the present invention.

13 (A) and (B) show each crystal plane, Se concentration, Z
FIG. 4 is a diagram illustrating a relationship among n concentration, carrier concentration, and resistivity.

FIG. 14 is a diagram (part 1) for explaining the principle of the third embodiment of the present invention;

FIG. 15 is a diagram (part 2) for explaining the principle of the third embodiment of the present invention;

FIG. 16 is a diagram (part 3) for explaining the principle of the third embodiment of the present invention;

FIG. 17 is a diagram showing a third embodiment of the present invention.

FIG. 18 is a view showing a modification of the third embodiment.

FIG. 19 is a view showing another modification of the third embodiment.

20 (A) and (B) are views showing steps for manufacturing the laser diode of FIG. 19;

FIG. 21 is a diagram (part 1) for explaining the principles of the fourth to seventh embodiments of the present invention;

FIGS. 22A and 22B are diagrams (part 2) for explaining the principles of the fourth to seventh embodiments;

FIG. 23 is a diagram showing a fourth embodiment of the present invention.

FIG. 24 is a view showing a modification of the fourth embodiment.

FIG. 25 is a view showing another modification of the fourth embodiment.

FIG. 26 is a view showing still another modified example of the fourth embodiment.

FIG. 27 is a diagram showing a fifth embodiment of the present invention.

FIG. 28 is a view showing a modification of the fifth embodiment.

FIG. 29 is a view showing another modification of the fifth embodiment.

FIG. 30 is a diagram showing a sixth embodiment of the present invention.

FIGS. 31A to 31D are views (part 1) illustrating manufacturing steps of the sixth embodiment;

FIGS. 32 (E) to (G) are views (No. 2) showing the manufacturing steps of the sixth embodiment.

33 (H) to (J) are views (No. 3) showing the manufacturing steps of the sixth embodiment.

FIGS. 34 (K) to (M) are views (No. 4) showing the manufacturing steps of the sixth embodiment.

FIG. 35 is a diagram showing a seventh embodiment of the present invention.

FIG. 36 is a view showing a modification of the seventh embodiment.

FIG. 37 is a view showing another modification of the seventh embodiment.

FIG. 38 is a drawing (part 1) illustrating a manufacturing step of the laser diode according to the eighth embodiment of the present invention;

FIG. 39 is a view (No. 2) showing a step of manufacturing the laser diode according to the eighth embodiment of the present invention;

FIG. 40 is a diagram showing a main part of a laser diode according to an eighth embodiment of the present invention.

FIG. 41 is a view showing the structure of a conventional ridge-type laser diode.

FIG. 42 is a diagram illustrating astigmatism generated in a conventional ridge-type laser diode.

FIG. 43 is a view showing a conventional stripe-type laser diode.

[Explanation of symbols]

300, 340, 400 Substrate structure 301, 341, 401, 441 'p-type GaAs substrate 321, 421, 441, 461, 501, 601, 7
01 n-type GaAs substrate 302, 322, 342, 442 GaAs current confinement structure 303, 323, 344, 402, 423, 462, 5
02,602 GaAs buffer layer 304,308,403,408,424,428,4
43,447,466,467,503,509,51
0 InGaP intermediate layers 305, 307, 327, 345, 347, 349, 4
04,406,407,425,427,444,44
6,463,465,502,504,507,50
8,605,705,707 InGaAlP cladding layer 306,348,426,405,445,464,5
06, 603, 706 InGaP active layers 301a, 321a, 341a, 401a, 421a,
441a, 461a, 501a, 601a stripe structure _{301c, 303b 1, 303b 2,} 321b 1, 32
_{1b 2, 321c, 343a, 343b} 1, 343
_{b 2, 401c, 401b 1,} 401b 2, 441c,
441b ₁ , 441b ₂ non-equivalent crystal plane

──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 4-51563 (32) Priority date Hei 4 (1992) March 10 (33) Priority claim country Japan (JP) (31) Priority Claim No. Japanese Patent Application No. 4-68000 (32) Priority Date Hei 4 (1992) March 26 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-132304 (32) Priority Japan, Japan (JP) (72) Inventor Mami Sugano 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Megumi Domo Fujitsu Co., Ltd. 1015 Fujitsu Limited (56) JP-A-2-240988 (JP, A) JP-A-3-34537 (JP, A) JP-A-1-109786 (JP, A) JP-A-1-243490 (JP, A) JP-A-4-361587 (JP, A) JP-A-5-63304 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01S 3/18

Claims (48)

(57) [Claims] 1. The method according to claim 1 , further comprising the steps of:
A plurality of crystallographically non-
First stripe structure defined by equivalent crystal plane
Formed on the surface of the semiconductor substrate.
The InGaAlP layer is formed of In, G
a, Al and P gas phase raw materials
It is formed while maintaining epitaxy on the substrate,
At this time, the first stripe structure is provided on the InGaAlP layer.
Defined with multiple crystallographically non-equivalent crystal planes corresponding to the structure
Having a structure in which the formed second stripe structure is formed
In the method of manufacturing a laser diode, during the growth of the InGaAlP layer, the In, Ga, A
Adding Mg vapor phase raw material to l and P vapor phase raw materials
The InGaAlP layer is formed by the second strike
A substantially uniform key regardless of the crystal planes forming the
And doping the InGaAlP layer at a carrier concentration of p-type.
Supply of the gaseous source material of the first step is to start the growth of the InGaAlP layer.
Starting before the starting step, wherein the InGaAlP
From the beginning to the end of the layer growth, Mg was added to the InGaAs.
characterized by being introduced in a substantially uniform concentration into the IP layer
Manufacturing method of a laser diode. 2. The gaseous phase raw material of Mg has a formula (C ₅ H ₅ )
₂ Biscyclopentadienyl magnesium represented by Mg
The method of claim 1, comprising a system. 3. The stripe structure has a <011> direction.
And a stripe-shaped upper main surface extending in the <011> direction.
Formed by a pair of existing striped side walls.
A top structure having a (100) plane orientation,
The side wall surface has a (311) B plane orientation.
The method of claim 1, wherein 4. The method according to claim 1 , wherein said InGaAlP layer is formed.
After that, epitaxy is maintained on the InGaAlP layer.
While holding the InGa so as to include the stripe structure.
Undoped semiconductor with narrower bandgap than AlP
A step of growing the body layer as an active layer.
The method of claim 1, wherein 5. The method according to claim 1, further comprising the step of forming said InGaAs on said substrate.
Before the growth of the IP layer is started ,
Forming a p-type semiconductor layer by
The step of forming the conductor layer is performed simultaneously with the raw material of the semiconductor layer.
Supplying a p-type dopant other than Mg;
By adding a phase source to the gas phase source of the semiconductor layer,
Starting the supply of Mg.
From the start of the AlP layer formation process, the conductivity is maintained at the desired concentration level.
2. The method according to claim 1, wherein the method is performed. 6. The method of claim 1, further comprising forming the InGaAlP layer.
Before starting, a narrower band than InGaAlP
Active layer made of an undoped semiconductor having a
To match the stripe structure on the substrate
Formed while maintaining epitaxy for one substrate,
Forming an InGaAlP layer on the active layer.
In addition, the step of doping the InGaAlP layer is performed by M
g of a dopant other than the InGa
Supplying at the same time as the start of the AlP layer forming step;
g was introduced into the InGaAlP layer at a sufficient concentration.
After that, a step of shutting off the supply of Mg.
The method of claim 1, wherein 7. The surface formed on a surface of a semiconductor substrate.
A plurality of each extending parallel to each other in a predetermined direction
A first stratum defined by crystallographically non-equivalent crystal faces
And a first stripe on the semiconductor substrate.
Gas phase of In, Ga, Al and P to include
Decomposition of the raw material causes epitaxy on the semiconductor substrate.
The InGaAlP layer formed while maintaining the
The InGaAlP layer corresponds to the first stripe structure.
Formed by multiple crystallographically unequal crystal faces
Laser diode having second stripe structure formed
In the method of manufacturing a semiconductor device, during the growth of the InGaAlP layer, the In, Ga, A
p-type dopant and n-type dopant
By adding punt in the form of a gaseous raw material,
The electrical properties of the GaAlP layer are controlled by the laser diode drive.
The current is reduced by the first and second stripe structures.
To selectively flow through any particular crystal plane,
Changing according to the crystal plane of the InGaAlP layer
A method for manufacturing a laser diode, comprising: 8. The crystallographically non-equivalent crystal planes
The InG including (100) plane and (311) B plane;
The step of doping the aAlP layer is performed as a p-type dopant.
Mg vapor source and Se vapor as n-type dopant
And the steps of simultaneously adding the ingredients, wherein the concentrations of Mg and Se are:
The InGaAsP layer is doped p-type, at which time (1
(3) the carrier concentration in the region grown on the (00) plane is (311)
It will be higher than the carrier concentration in the region grown on the B surface
The method according to claim 7, wherein the method is set as follows. 9. The InGaAlP layer is made of Mg.
The Mg concentration in the InGaAlP layer is on the (100) plane.
And (311) 1 × in each region on the B-plane.
Doped to 10 ¹⁸ cm ^-3 , and
The Se concentration in the InGaAlP layer is (100) plane.
4 × 10 ¹⁷ cm ⁻³ in the upper region, on the (311) B surface
8 × 10 ¹⁷ doping is such that the cm ^-3 in the region
9. The method of claim 8, wherein the method is performed. 10. The plurality of crystallographically non-equivalent crystal faces.
Includes the (100) plane and the (311) B plane,
In the step of doping the GaAlP layer, a p-type dopant is used.
Mg raw material and Se vapor as n-type dopant
Including the step of simultaneously adding the raw materials, the concentration of Mg and Se
Indicates that the InGaAsP layer is located in a region on the (100) plane.
In the region on the (311) B plane
8. The method according to claim 7, wherein the n-type dopant is doped.
Method. 11. The InGaAlP layer is made of Mg.
The Mg concentration in the InGaAlP layer is (100)
In each area on the plane and on the (311) B plane
Doped to 1 × 10 ¹⁸ cm ^-3 and added to Se
Thus, the Se concentration in the InGaAlP layer is (100)
6 × 10 ¹⁷ cm ^{-3 in} area on plane , (311) B plane
In the upper region, ^doping is performed so as to be 1.2 × 10 ¹⁸ cm ^−3.
The method according to claim 10, wherein the step is performed. 12. The plurality of crystallographically unequal crystal planes.
Includes the (100) plane and the (311) B plane,
In the step of doping the GaAlP layer, a p-type dopant is used.
Gas phase material of Zn and gas phase of Se as n-type dopant
Including the step of simultaneously adding the raw materials, the concentration of Zn and Se
Shows that the InGaAsP layer is doped n-type,
(3) In the region on the (100) plane,
11) Set to be higher than the area on the B side.
The method of claim 7, wherein: 13. The InGaAlP layer is made of Zn.
The Zn concentration in the InGaAlP layer is (100)
As in the area of the surface becomes 6 × 10 ¹⁷ cm ^-3, or
1.8 × 10 ¹⁸ cm in the area on the (311) B plane
^-3 , and the above-mentioned In
The Se concentration in the GaAlP layer is in the region on the (100) plane.
1 × 10 ¹⁸ cm ^-3 in (311) B area
Is doped to 2 × 10 ¹⁸ cm ^-3
13. The method of claim 12, wherein the method comprises: 14. The crystallographically non-equivalent crystal planes.
Includes the (100) plane and the (311) B plane,
In the step of doping the GaAlP layer, a p-type dopant is used.
Gas phase material of Zn and gas phase of Se as n-type dopant
Including the step of simultaneously adding the raw materials, the concentration of Zn and Se
Indicates that the InGaAsP layer is located in a region on the (100) plane.
And becomes p-type in the region on the (311) B plane.
8. The method according to claim 7, wherein the setting is made such that:
Law. 15. The InGaAlP layer is made of Zn.
The Zn concentration in the InGaAlP layer is (100)
As in the area of the surface becomes 7 × 10 ¹⁷ cm ^-3, or
2.1 × 10 ¹⁸ cm in the area on the (311) B plane
^-3 , and the above-mentioned In
The Se concentration in the GaAlP layer is in the region on the (100) plane.
1 × 10 ¹⁸ cm ^-3 in (311) B area
Is doped to 2 × 10 ¹⁸ cm ^-3
15. The method according to claim 14, wherein the method comprises: 16. A crystallographically non-equivalent crystallographic plane.
Includes (100) plane and (311) A plane,
In the step of doping the GaAlP layer, a p-type dopant is used.
Gas phase material of Zn and gas phase of Se as n-type dopant
Including the step of simultaneously adding the raw materials, the concentration of Zn and Se
Indicates that the InGaAsP layer is located in a region on the (100) plane.
And becomes p-type in the region on the (311) B plane.
8. The method according to claim 7, wherein the setting is made such that:
Law. 17. The InGaAlP layer is made of Zn.
The Zn concentration in the InGaAlP layer is (100)
So as to 2 × 10 ¹⁶ cm ^-3 in the region on the surface, or
And (311) to 1 × 10 ¹⁸ cm ^-3 in the region on the surface A
Is dough-flop so that, also by Se, the InGa
In the region where the Se concentration in the AlP layer is on the (100) plane
1 × 10 ¹⁸ cm ⁻³ , 6 in the area on the (311) A plane
Characterized by being doped so as to be × 10 ¹⁸ cm ^-3
The method of claim 14, wherein 18. The method according to claim 18, further comprising the step of : adjoining said InGaAlP layer.
Then, an n-type second InGaAlP layer is formed on the first and second layers.
A pn junction is formed between the first and second InGaAlP layers as described in (3) above.
11) Form so as to correspond to the area on the A-plane
17. The method of claim 16, comprising the step of: 19. The plurality of non-equivalent crystallographic planes.
Includes (100) plane and (311) A plane,
In the step of doping the GaAlP layer, a p-type dopant is used.
Gas phase material of Zn and gas phase of Se as n-type dopant
Including the step of simultaneously adding the raw materials, the concentration of Zn and Se
Indicates that the InGaAsP layer is located in a region on the (100) plane.
And has the first resistivity, and (3
11) The region on the A-plane becomes p-type and becomes the second larger
It is set to have threshold resistivity
The method of claim 7. 20. The plurality of non-equivalent crystallographic planes
A first crystal plane corresponding to the main surface of the substrate,
A second crystal plane having an orientation different from that of the first crystal plane;
The second crystal plane forms a step on the substrate surface.
The method of claim 7, wherein: 21. A process for doping the InGaAlP layer.
In the process, the InGaAlP layer is formed on the first crystal plane.
In the region, the first conductivity type is changed to a region on the second crystal plane.
Implemented to have a second, opposite conductivity type in the region
21. The method of claim 20, wherein: 22. The second crystal plane is a (311) A plane.
And forming the InGaAlP layer in a second stripe structure.
Structure includes the (311) A plane corresponding to the second crystal plane.
21. The method of claim 20, wherein 23. The second crystal plane is (411) A plane.
Forming a step on the substrate;
The aAlP layer has a structure in which the second stripe structure has the second stripe structure.
Formed so as to include the (411) A plane corresponding to the crystal plane of
21. The method of claim 20, wherein the method comprises: 24. Forming the first stripe structure
The process is performed on a (100) plane as a main surface of the semiconductor substrate.
Characterized by including a step of forming a crystal plane inclined with respect to
21. The method of claim 20, wherein: 25. The first InGaAlP layer.
A second separate InGaAlP layer adjacent to the first
The second crystal plane between the first and second InGaAlP layers.
Excluding the region corresponding to
21. The method according to claim 20, further comprising the step of:
Law. 26. The p-type dopant and the n-type dopant
The step of adding a part is performed simultaneously.
The method according to any one of claims 20 to 25.
Law. 27. The method further comprises decomposing the raw materials of Ga and As.
Thereby, the GaAs layer is etched with respect to the semiconductor substrate.
While maintaining the pitaxy, the GaAs layer
Third strike corresponding to the first and second stripe structures
Including forming a rib structure to form
The third stripe structure is formed by the first and second strikes.
Defined by the crystal plane corresponding to the crystal plane forming the live structure
Wherein the step of forming the GaAs layer comprises:
By adding the gaseous raw materials of Se and Se, the Ga
The As layer is formed by Zn and Se at the same time.
The electrical properties of the region grown on the (100) plane and other
Doping differently from the region grown on the crystal plane
The method of claim 7, comprising the step of: 28. The step of doping the GaAs layer,
The region where the resistivity of the GaAs layer has grown on the (100) plane
At lower than the area grown on other crystal planes
28. The method according to claim 27, which is performed as follows.
Law. 29. The step of doping the GaAs layer,
In the region where the GaAs layer has grown on the (100) plane, p
And n-type in the region grown on other crystal planes
28. The method according to claim 27, wherein the processing is performed as follows.
the method of. 30. A longitudinal direction from a first end to a second end.
An extended semiconductor substrate; formed as a part of the substrate surface ;
A first strut comprising a (100) plane extending in a longitudinal direction;
And the long side on both sides of the
And (100) planes
A pair of different stripe planes defined by different crystal planes
A first stripe structure comprising: a first stripe structure extending longitudinally from a first end to a second end on the substrate ;
And is formed so as to exist with the first stripe structure.
Of InGaAlP including a corresponding stripe structure
A first cladding layer; on the first cladding layer, from a first end to a second end
The first strut is formed to extend in the longitudinal direction, and
A stripe structure corresponding to the first structure;
The band gap is narrower than the band gap of the cladding layer.
An active layer composed of an undoped semiconductor material; and on the active layer, a longitudinal direction from a first end to a second end.
Extending to the first stripe structure.
InGaAlP layer with corresponding stripe structure
A second electrode provided on the lower surface of the substrate and in ohmic contact with the second electrode;
Means for providing ohmic contact with the second cladding layer
In a laser diode comprising a second electrode means, one of the first and second cladding layers is made of Mg.
A substantially uniform darkness regardless of the stripe structure.
The first and second claddings, which are heavily doped
Characterized in that the other of the layers is doped n-type.
Laser diode. 31. A first end doped with a first conductivity type.
A semiconductor substrate extending in a longitudinal direction from to a second end; formed as a part of the substrate surface, and
A crystal plane having a first crystal orientation extending in the longitudinal direction
A first stripe surface, and the first stripe surface
Is formed to extend in the longitudinal direction adjacent to
A second plane defined by crystal planes having different crystal orientations;
A first stripe composed of two stripe surfaces
A structure extending longitudinally from a first end to a second end on the substrate ;
A first layer of InGaAlP formed to be
A cladding layer; a first stripe structure on the first cladding layer;
In the longitudinal direction until the first end or we second end in alignment with, the
Formed to extend as part of the first cladding layer
Corresponding to the first stripe surface,
And extending from the crystal plane having the first crystal orientation.
A third stripe surface formed and the second stripe
The second crystallographic direction, corresponding to the plane, extending in the longitudinal direction.
Fourth stripe surface formed by a crystal plane having a phase
A second stripe structure defined by: from the first end to the second end on the first cladding layer
Undoped semiconductor material formed to extend in the longitudinal direction
And a first carrier of a first polarity and a second carrier of a first polarity.
A second carrier having a reverse polarity is supplied to the first carrier;
A light beam is formed by recombination of the rear and the second carrier.
An active layer; and forming the first and second stripe structures on the active layer.
Combined from the first end to the second end in the longitudinal direction,
Formed so as to extend as a part of the layer,
3 corresponding to the stripe surface, extending in the longitudinal direction,
A fifth crystal plane formed from the crystal plane having the first crystal orientation;
Corresponding to the stripe surface and the fourth stripe surface,
A crystal extending in the longitudinal direction and having the second crystal orientation
Defined by a sixth stripe surface formed by the surface
A third stripe structure on the active layer in a longitudinal direction from a first end to a second end ;
A fourth layer made of an InGaAlP layer formed so as to extend.
A second clad layer; and the first to third stripes on the second clad layer.
Longitudinally from the first end to the second end in alignment with the loop structure
So as to extend as a part of the second cladding layer.
And corresponds to the fifth stripe surface.
A crystal extending in the longitudinal direction and having the first crystal orientation
A seventh stripe surface formed from the surface and the sixth stripe surface.
The second surface corresponding to the tripe surface and extending in the longitudinal direction;
Eighth strike formed by a crystal plane having a crystal orientation of
A fourth stripe structure defined by a rib surface; and a fourth stripe structure provided on the lower surface of the substrate and in ohmic contact with the lower surface.
The first carrier is provided on the active layer and the first cladding is provided on the active layer.
A first electrode means for injecting through the layer; provided on said second cladding layer,
Contacting the second carrier with the active layer,
It more and second electrode means for injecting through the cladding layer
In one laser diode, one of the first and second cladding layers has at least
Partially doped with p-type and n-type dopants.
The drive current of the laser diode is
The fifth stripe in the third stripe structure.
Selective injection through the area defined in the rip zone
A laser diode characterized by the above-mentioned. 32. The p-type dopant comprises Zn,
The n-type dopant is made of Se.
32. The laser diode according to claim 31. 33. The first, third, fifth and seventh switches.
The tripe plane is composed of the (100) plane,
The sixth and eighth stripe planes are smaller than the (311) B plane.
The first to eighth stripe surfaces are oriented in the <011> direction.
33. The device according to claim 31, wherein the device extends.
Laser diode. 34. The first, third, fifth and seventh switches.
The trip surface is the second, fourth, sixth or eighth strike.
Sideways due to a pair of (311) B planes that make up the life plane
And constitute one of the pair of stripe surfaces.
(311) The B plane is the first when viewed in the <011> direction.
(311) B plane is <011> direction
Characterized by being inclined in the second opposite direction when viewed from above.
The laser diode according to claim 33, wherein 35. The first, third, fifth and seventh switches.
The tripe plane is formed from the (100) plane.
4, 6th and 8th stripe planes are (311) A plane
And the first to eighth stripe surfaces are <01-
32. The device according to claim 31, which extends in the 1> direction.
Laser diode. 36. The first, third, fifth and seventh switches.
Each of the tripe surfaces is, from the side, the second, fourth, sixth
Alternatively, a pair of (311) forming the eighth stripe surface
One of the pair of (311) A surfaces
Is inclined in the first direction when viewed in the <01-1> direction.
And the other is inclined in a second, opposite direction.
A laser diode according to claim 35. 37. The first, third, fifth and seventh switches.
The tripe plane is a crystal plane inclined with respect to the main surface of the substrate.
The second, fourth, sixth and eighth strikes
The crystal plane coincides with the crystal plane constituting the main surface of the substrate.
Rezada of claim 31, wherein that you made of surface
Iod. 38. The first, third, fifth and seventh switches.
The tripe surface is composed of the (311) A surface.
A laser diode according to claim 37. 39. The first, third, fifth and seventh switches.
The tripe plane is characterized by being composed of a (411) A plane.
A laser diode according to claim 37. 40. The first and third cladding layers.
One of them is at least partly the first and the second.
A first dopant having one of two conductivity types
Simultaneously with the second dopant having the other conductivity type.
And the driving current of the laser diode is
A region corresponding to the fifth stripe surface in the active layer.
Forming a current constriction structure for selectively injecting into the region; the cladding layer forming the current constriction structure comprises a first sub-block.
A first sub-cladding layer ; and a first sub-cladding layer.
The doping level at the same time
Wherein the respective doping levels are
The first sub-cladding layer is formed on the fifth stripe surface.
In the corresponding region having the first crystal orientation, the first
Doping to the conductivity type of the dopant and carrying
The density is set to increase, and the sixth strike
In the region having the second crystal orientation corresponding to the live plane
To be doped to the conductivity type of the second dopant.
Set; the second sub-cladding layer is provided with the first dopant;
To the first conductivity type by the dopant having the same conductivity type
The first stripe corresponding to the fifth stripe surface.
In a region having a crystal orientation, the sixth stripe surface
Having a higher carrier concentration than the region corresponding to
The laser diode according to claim 31, wherein: 41. A first end doped with a first conductivity type.
A semiconductor substrate extending in a longitudinal direction from to a second end; formed as a part of the substrate surface, and
A crystal plane having a first crystal orientation extending in the longitudinal direction
A first stripe surface, and the first stripe surface
Is formed to extend in the longitudinal direction adjacent to
A second plane defined by crystal planes having different crystal orientations;
A first stripe composed of two stripe surfaces
A structure extending longitudinally from a first end to a second end on the substrate ;
A first semiconductor comprising a compound semiconductor formed to exist
A lad layer; and the first stripe structure on the first cladding layer.
Longitudinally from a first end to a second end in alignment with
Formed to extend as part of the first cladding layer
Corresponding to the first stripe surface,
And extending from the crystal plane having the first crystal orientation.
A third stripe surface formed and the second stripe
The second crystallographic direction, corresponding to the plane, extending in the longitudinal direction.
Fourth stripe surface formed by a crystal plane having a phase
A second stripe structure defined by: from the first end to the second end on the first cladding layer
Undoped semiconductor material formed to extend in the longitudinal direction
And a first carrier of a first polarity and a second carrier of a first polarity.
A second carrier having a reverse polarity is supplied to the first carrier;
A light beam is formed by recombination of the rear and the second carrier.
An active layer; and forming the first and second stripe structures on the active layer.
Combined from the first end to the second end in the longitudinal direction,
Formed so as to extend as a part of the layer,
3 corresponding to the stripe surface, extending in the longitudinal direction,
A fifth crystal plane formed from the crystal plane having the first crystal orientation;
Corresponding to the stripe surface and the fourth stripe surface,
A crystal extending in the longitudinal direction and having the second crystal orientation
Defined by a sixth stripe surface formed by the surface
A third stripe structure on the active layer in a longitudinal direction from a first end to a second end ;
A second compound semiconductor layer formed so as to extend;
A first cladding layer and a first cladding layer on the second cladding layer.
Longitudinally from the first end to the second end in alignment with the loop structure
So as to extend as a part of the second cladding layer.
And corresponds to the fifth stripe surface.
A crystal extending in the longitudinal direction and having the first crystal orientation
A seventh stripe surface formed from the surface and the sixth stripe surface.
The second surface corresponding to the tripe surface and extending in the longitudinal direction;
Eighth strike formed by a crystal plane having a crystal orientation of
A fourth stripe structure defined by a rib surface ; and a fourth stripe structure provided on the lower surface of the substrate and in ohmic contact therewith,
The first carrier is provided on the active layer and the first cladding is provided on the active layer.
A first electrode means for injecting through the layer; provided on said second cladding layer,
Contacting the second carrier with the active layer,
A second electrode means for injecting through a cladding layer of
In the laser diode, the second crystal orientation is a crystal plane corresponding to the main surface of the substrate.
Wherein the second crystallographic orientation is relative to the main surface of the substrate.
Defining an inclined crystal plane Te and; wherein one of the first and second cladding layer, at least
Partially one of the first and second conductivity types
And a first dopant having the other conductivity type.
Laser die doped with two dopants
The drive current of the diode is applied to the active layer,
Part defined by the fifth stripe region in the loop structure
Forming a current constriction structure that is selectively injected through the cladding layer ;
Consists two sub cladding layer; said first sub-clad layer, said first and second de
-Doped to each doping level by punting,
At this time, the respective doping levels are adjusted to the first level.
A bucladding layer corresponds to the fifth stripe surface and has a first
The first dopant in a region having a crystal orientation of
And the carrier concentration is increased.
Is set to be large and the sixth stripe surface
In a region having a corresponding second crystal orientation, the second
The second sub-cladding layer is configured to be doped with a conductivity type of
To the first conductivity type by the dopant having the same conductivity type
The first stripe corresponding to the fifth stripe surface.
In a region having a crystal orientation, the sixth stripe surface
Having a higher carrier concentration than the region corresponding to
Laser diode featuring. 42. The first crystal orientation is opposite to the main surface of the substrate.
Then, the angle of the range between the (311) A plane and the (411) A plane
43. The lens according to claim 41, wherein the angle is inclined by degrees.
Laser diode. 43. The first crystal orientation is (31)
43. The method according to claim 42, wherein 1) defining the A side.
Laser diode. 44. The first crystal orientation according to (41),
43. The method according to claim 42, wherein 1) defining the A side.
Laser diode. 45. The active layer, wherein the first crystal orientation is
Region having the second crystal orientation
42. The method of claim 41, wherein the thickness is greater than the thickness.
A laser diode as described. 46. Each of said first and second cladding layers
In the region having the first crystal orientation,
The thickness is larger than the region having the second crystal orientation
46. The laser diode according to claim 41, wherein:
Iod. 47. The second crystal orientation is a (100) plane
The crystal plane inclined from the surface to the (111) A plane.
The method according to any one of claims 40 to 46, wherein
A laser diode as described. 48. The first stripe structure comprises a substrate main body.
It consists of a groove extending in the longitudinal direction on the surface, and said groove is a pair
Are sandwiched from the side by the opposing side walls,
The first stripe surface is one of the pair of opposed side walls.
And the second to fourth stripe structures are each
The first cladding layer, the active layer and the second
A corresponding groove is formed on the cladding layer, and the second electrode
The step is formed so as to fill a groove on the second cladding layer.
Characterized by having a flattened main surface.
46. The laser diode according to 46.