JPH10321947A - Semiconductor laser diode and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the light output without increasing the operating current, by forming an Si-doped region in a part of a second clad layer near each resonance end face. SOLUTION: In an impurity diffusion clad layer region 10 of a p-AlGaInP clad layer 4, an Si-diffused impurity diffusion region 11 is formed. Therefore, in the Si impurity diffusion region 11 formed in the p-AlGaInP clad layer 4 near each resonance end face, p-type carriers and n-type carriers of the diffused n-type dopant generated by Si, are compensated for by each other, thereby making the carrier concentration low and a resistance value high. Preferably, the concentration of the Si impurities in the Si impurity diffusion region 11 is set to at most 1/3 that of the p-AlGaInP clad layer 4 (a part except for the resonance end face area where no Zn nor Si is diffused).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser diode having a window structure having high reliability under a high output operation.

[0002]

2. Description of the Related Art In recent years, semiconductor laser diodes have been widely used in various fields such as optical communications, compact disk players, other electronic devices, and processing / measuring devices. The conventional semiconductor laser diode shown in FIG. 11 is a 0.67 μm band semiconductor laser diode having a double heterostructure, which can efficiently inject current into the active layer and effectively emit light into the active layer. The configuration is as follows, for the purpose of confinement.

That is, n- (Al _0.7 Ga _0.3 ) is formed on an n-GaAs substrate 1 having an n-side electrode 16 formed on the lower surface.
_0.5 In _0.5 P cladding layer 2, In _0.5 Ga _0.5 P quantum well active layer 3, p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4, n-GaAs current blocking layer 14, p-GaAs
The s-second contact layer 15 and the p-side electrode 17 are stacked as shown in FIG. Here, FIG. 11, FIG.
In the vicinity of the resonance end face of No. 2, the hatched portion indicates a portion where Zn impurities are diffused, and the portion denoted by reference numeral 9 indicates a portion where In
_{The 0.5} Ga _0.5 P quantum well active layer 3 is a disordered active layer in which the quantum well active layer 3 has been disordered.
(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 2 and p-
(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P is an impurity diffusion cladding layer region in which Zn impurities are diffused in the cladding layer 4. Here, in this specification, (p−) and (n−) indicate p-type and n-type, respectively, which indicate p-type conductivity and n-type conductivity.

Incidentally, p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P
The clad layer 4 has a stripe-shaped thick portion (hereinafter, referred to as a ridge portion) elongated in the resonance direction at the center in the width direction, and the n-GaAs current blocking layer 14.
Are formed on the upper surface, side surfaces, and both sides of the ridge portion so as to cover the impurity diffusion cladding layer region 10, and are formed on both sides of the ridge portion except for the upper surface of the ridge portion except for the region 10. Is formed. On the upper surface of the ridge except for the impurity diffusion cladding layer region 10, that is, on the portion where the n-GaAs current blocking layer 14 is not formed, a p-GaAs first contact layer 5 is formed as shown in FIG. ing.

In the conventional semiconductor laser diode configured as described above, when a voltage is applied so that the p-side electrode 17 becomes positive (+) and the n-side electrode 16 becomes negative (−), holes (holes) are generated. ) Is p-GaAs second
The In _0.5 Ga _0.5 P quantum well active layer 3 is injected through the contact layer 15, the p-GaAs first contact layer 5, and the p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4, and electrons are injected. , N-GaAs substrate 1 and n- (Al
_0.7 Ga _0.3 ) _0.5 In _0.5 P via the cladding layer 2
_0.5 Ga _0.5 P is injected into the quantum well active layer 3 and In _0.5
Holes and electrons are recombined in the Ga _0.5 P quantum well active layer 3 to generate light. At this time, if the amount of carriers (electrons and holes) injected into the active layer 3 is sufficiently increased to generate light exceeding the loss of the waveguide, laser oscillation occurs.

In the conventional semiconductor laser diode having a ridge structure (having a ridge portion) shown in FIG. 11, a p-GaAs second contact layer 15 and an n-GaAs current block layer 14 are provided on both sides of the ridge portion. And p- (A
l _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4
When a voltage is applied so that the p-side electrode becomes positive when the p-side electrode becomes positive, a reverse bias occurs and no current flows. That is, n
The current blocking layer 14 literally fulfills the function of blocking the current; As a result, the current is injected into the active layer 3 only through the ridge portion, so that the current is intensively injected into the active layer 3 immediately below the ridge portion, and reaches a current density sufficient for laser oscillation. Further, the n-GaAs current blocking layer 14 has a property of absorbing the laser light generated in the active layer 3 because the band gap energy of GaAs is smaller than the band gap energy of In _0.5 Ga _0.5 P constituting the active layer 3. Having. For this reason, on both sides of the ridge, the generated laser light is strongly absorbed, so that it can be concentrated only in the vicinity of the ridge, and the horizontal transverse mode can be made a stable single mode.

In general, the maximum light output of an AlGaAs-based semiconductor laser diode that generates laser light having a wavelength in the 0.75 to 1.0 μm band is determined by the light output at which end face breakdown occurs. In the end face breakdown, the injected carriers undergo non-radiative recombination via the surface state near the end face, so that the number of carriers decreases near the end face and the effective band gap becomes narrower. Laser light is re-absorbed in the vicinity, and the crystal itself constituting the semiconductor laser is melted by heat due to the re-absorption.
Therefore, in order to realize a high light output operation in a semiconductor laser diode, it is necessary to make it difficult to absorb the laser light in the end face region and to make the vicinity of the end face "transparent" to the laser light. .

Therefore, in the conventional semiconductor laser diode, in order to provide a region in which the band gap energy becomes higher than that of the active region of the active layer 3 near the laser resonator end face, the In impurity is diffused by Zn and heat treatment is performed.
_The window structure has a disordered active layer 9 in which the _0.5 Ga _0.5 P quantum well active layer 3 is disordered.

[0009]

However, in the conventional semiconductor laser diode, the current flows through the p-side electrode 17 → the p-GaAs second contact layer 15 → the p-GaAs first contact layer 5 → p − (Al
_0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4 → In _0.5 Ga
_0.5 P quantum well active layer 3 → n- (Al _0.7 Ga _0.3 ) _0.5 I
It flows along the path of n _0.5 P cladding layer 2 → n-GaAs semiconductor substrate 1, but in the window structure portion (near the resonance end face), Z
Due to the effect of diffusion of the n impurity, p- (Al _0.7 Ga _0.3 )
In the impurity diffusion region of the _0.5 In _0.5 P cladding layer 4, p-type
The carrier (hole) concentration is p, where Zn is not diffused.
− (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P It is at least 5 times higher than that of the cladding layer 4. As a result, the specific resistance decreases,
A current flows very easily through the Zn impurity diffusion region 10, and a reactive current that does not contribute to laser oscillation at all flows through the region 10 as indicated by an arrow in FIG. For this purpose, a current for operating the semiconductor laser (operating current)
There is a problem that the current increases due to the reactive current flowing in this region.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a semiconductor laser diode capable of high optical output without increasing the operating current.

[0011]

SUMMARY OF THE INVENTION The present invention has been made as a result of studying a structure for reducing the above-mentioned reactive current and a method of manufacturing the same in order to solve the above-mentioned problems of the prior art. That is, the first semiconductor laser diode according to the present invention comprises: a first cladding layer made of an n-type compound semiconductor; an active layer made of a compound semiconductor grown on the first cladding layer; A second cladding layer formed of a p-type compound semiconductor and having a ridge formed from one resonance end face to the other resonance end face on the upper surface, and the second cladding layer near each of the resonance end faces. A semiconductor laser diode having a window structure in which the active layer near each of the resonance end faces is disordered by doping Zn in the thickness direction from the upper surface of the cladding layer to the middle of the first cladding layer. A Si-doped region is formed in the second cladding layer near the end face. With such a structure, a high-resistance region doped with Si can be formed in the second cladding layer in the vicinity of each resonance end face, and the current flowing into the disordered active layer can be reduced. Therefore, the reactive current can be reduced.

Further, a second semiconductor laser diode according to the present invention comprises a first clad layer made of an n-type compound semiconductor, an active layer made of a compound semiconductor grown on the first clad layer, A second cladding layer made of a p-type compound semiconductor grown on the active layer and having a ridge formed on one surface from one resonance end surface to the other resonance end surface; and a second cladding layer on both sides of the ridge portion. A current blocking layer made of an n-type compound semiconductor grown on the cladding layer, and in the thickness direction from the upper surface of the second cladding layer to the middle of the first cladding layer in the vicinity of each of the resonance end faces. A semiconductor laser diode having a window structure in which an active layer near each of the resonance end faces is disordered by doping Zn, wherein a ridge portion of the second cladding layer near each of the resonance end faces is thinned. Characterized in that the formation of the current blocking layer so as to cover the thin comb was ridge above. With such a structure, a pn junction can be formed between the second cladding layer and the current blocking layer in the vicinity of each resonance end face, and the second pn junction can be formed in the vicinity of each resonance end face. Since the current flowing from the cladding layer to the current blocking layer can be blocked, the current flowing into the disordered active layer can be reduced, and the reactive current can be reduced. Here, in the first and second semiconductor laser diodes, the n-type compound semiconductor refers to a compound semiconductor exhibiting n-type conductivity, and the p-type compound semiconductor refers to p-type conductivity. Means a compound semiconductor.

Further, in the first and second semiconductor laser diodes according to the present invention, the first cladding layer and the second cladding layer have a general formula (Al _x Ga _{1 -x} ) _y In _{1 -y} P (However, 0.65 ≦ x ≦ 0.75, 0.45 ≦ y ≦ 0.5
5) wherein the active layer is of the general formula In _s Ga _{1 -s} P (where 0.45 ≦ s ≦ 0.55)
It is preferable to consist of a compound semiconductor represented by

Further, a first method for manufacturing a semiconductor laser diode according to the present invention is characterized in that the first method for manufacturing a semiconductor laser diode comprises the steps of:
, An active layer made of a compound semiconductor grown on the first cladding layer, and a p-type compound semiconductor grown on the active layer. A semiconductor laser diode having a window structure including a second cladding layer in which a ridge portion is formed.
After doping Zn in the thickness direction from the upper surface of the second cladding layer to the middle of the first cladding layer to disorder the active layer in the vicinity of each resonance facet, the active layer in the vicinity of each resonance facet is disordered. The method includes doping the second cladding layer with Si. Thereby, it is possible to manufacture a semiconductor laser diode in which a region having a high resistance value doped with Si is formed in the second cladding layer near each resonance end face.

Further, according to a second method for manufacturing a semiconductor laser diode according to the present invention, the first method for manufacturing a semiconductor laser diode comprises the steps of:
, An active layer made of a compound semiconductor grown on the first cladding layer, and a p-type compound semiconductor grown on the active layer. And a current blocking layer made of an n-type compound semiconductor grown on the second cladding layer on both sides of the ridge portion. In the vicinity, a semiconductor laser diode having a window structure in which Zn is doped in the thickness direction from the upper surface of the second cladding layer to the middle of the first cladding layer so that the active layers near the resonance end faces are disordered. A manufacturing method, comprising thinning a ridge portion of the second cladding layer near each of the resonance end faces, and then growing the current blocking layer so as to cover the thinned ridge portion. The features. Thereby, a pn junction is formed between the second cladding layer and the current blocking layer near each resonance end face, and flows into the current blocking layer from the second cladding layer near each resonance end face. A semiconductor laser diode capable of blocking current can be manufactured.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. Note that, in the drawings of the embodiment described below,
The same reference numerals are given. Embodiment 1 FIG. The semiconductor laser diode according to the first embodiment of the present invention shown in FIG. 1 has a window structure as in the conventional example, and the p-type semiconductor laser diode shown in FIG.
In the impurity diffusion cladding layer region 10 of the (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4, S in which Si is diffused
characterized in that an i-diffusion impurity diffusion region 11 is formed,
Other parts are configured in the same manner as in the conventional example. In the semiconductor laser diode of the first embodiment, the reactive current in the window structure portion is reduced by forming the Si diffusion impurity diffusion region 11 as described later in detail.

First, a method of manufacturing the semiconductor laser diode according to the first embodiment will be described. In the manufacturing method, first, as shown in FIG. 2A, an n- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 2 and an In _0.5 Ga _0.5 P quantum well active layer 3 are formed on an n-GaAs semiconductor substrate 1. , P- (Al
_0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4, p-GaAs
Each layer of the first contact layer 5 is formed by epitaxial crystal growth. Next, as shown in FIG.
After a Si ₃ N ₄ film 6 is formed on the entire surface of the GaAs first contact layer 5, the Si ₃ N ₄ film and p-GaAs are formed only in the window region by photolithography and etching.
s The first contact layer 5 is removed by etching. Then, as shown in FIG. 3A, after a ZnO film 7 is formed on the entire surface of the wafer by using a method such as electron beam evaporation / sputtering, the wafer is cooled, for example, at a temperature of 550 ° C. to 650 ° C. for 30 minutes. By annealing under the conditions of minutes to 4 hours, S
i ₃ N ₄ film 6 Zn is diffused from the ZnO film 7 in the crystal the portion is not formed, an In _0.5 by Zn diffusion
Disordered active layer 9 in which Ga _0.5 P quantum well active layer 3 is disordered, n- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 2 and p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4 is formed. Incidentally, the portion covered by the Si ₃ N ₄ film 6 since the Si ₃ N ₄ film 6 prevents the diffusion of Zn, any Zn diffusion into the crystal under the Si ₃ N ₄ film 6 does not occur.

Next, after removing the ZnO film 7, FIG.
An Si film 8 is formed as shown in FIG. The film formation method is Z
The same method as that for the nO film can be used. And Z
As in the case of n diffusion, for example, 550 ° C. to 650 ° C.,
By annealing for 30 minutes to 4 hours,
By diffusing Si, p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5
S in the impurity diffusion cladding layer region 10 in the P cladding layer
An i impurity diffusion region 11 is formed. Next, after removing the Si film 8, a stripe-shaped resist film 12 is formed as shown in FIG. The resist film 12 as an etching mask, as shown in FIG. _{4 (a), Si 3 N} 4
The film 6 is etched in a stripe shape. Further, as shown in FIG. 4B, using the resist film 12 as an etching mask, the p-GaAs first contact layer 5 and the p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4 on both sides of the resist film 12 are formed. Is etched to a depth in the middle of the p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4.

Next, as shown in FIG. 5A, after the striped resist film 12 is removed with a resist stripping solution (in FIG. 5A, the reference numeral 13 denotes
This is a Si ₃ N ₄ film etched in a stripe shape. The current block layer 14 is formed by the second crystal growth, as shown in FIG. In this case, no crystal grows on the striped Si ₃ N ₄ film 13. As described above, as shown in FIG. 6A, the disordered active layer 9, the impurity diffusion cladding layer region 10, and the Si impurity diffusion region 11 are formed near the cavity end face. Then, after removing the stripe-shaped Si ₃ N ₄ film 13, the third crystal growth forms a p-GaAs second contact layer 15 as shown in FIG. 6B. next,
A p-side electrode 17 is formed on the p-GaAs second contact layer 15 by a method such as electron beam evaporation or sputtering.
By forming the n-side electrode 16 on the lower surface of the GaAs semiconductor substrate 1, the semiconductor laser diode of the first embodiment as shown in FIG. 1 is manufactured.

Embodiment 1 manufactured as described above
In the semiconductor laser diode of
The Si impurity diffusion region 11 formed in the-(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4 has a p-type carrier,
The n-type carrier formed by the diffused n-type dopant, Si, is mutually compensated to lower the carrier concentration and increase the resistance value. Here, the carrier concentration of the Si impurity diffusion region 11 is preferably the original p
-(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4 (p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4 in a portion where Zn and Si are not diffused except for near the resonance end face)
Or less, more preferably 1/7 of the carrier concentration of
The Si impurity concentration of the Si impurity diffusion region 11 is set as follows. As a result, as shown by arrows in FIG. 7, the current flowing through the Si impurity diffusion region 11 can be extremely reduced, so that the reactive current in the window region can be significantly reduced. Further, in the semiconductor laser diode of the first embodiment, the disordered active layer 9 is formed in the vicinity of the cavity end face of the active layer 3 as in the conventional example, so that the light in the active layer in the window region is not emitted. Absorption can be suppressed, and high light output characteristics similar to those of a conventional semiconductor laser diode having a window structure can be obtained.

Therefore, the semiconductor laser diode according to the first embodiment can output a high light without increasing the operating current.

Embodiment 2 FIG. Embodiment 2 according to the present invention
The difference between the semiconductor laser diode and the conventional example is that the p- (Al _0.7
After the thickness of the Ga _0.3 ) _0.5 In _0.5 P cladding layer 4 is reduced,
The n-GaAs current blocking layer 14 is formed so as to cover the thinned ridge portion, and the other portions are configured in the same manner as the conventional example. In the semiconductor laser diode according to the second embodiment configured as described above, p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 formed near the resonance end face.
The pn junction between the P cladding layer 4 and the n-GaAs current blocking layer 14 reduces the current injected into the disordered active layer 9 as described in detail below.

First, a method for manufacturing the semiconductor laser diode according to the second embodiment will be described. In this manufacturing method, the process up to FIG.
The rest will be described. First, in FIG. 3A, after Zn is diffused to remove the ZnO film 7, FIG.
As shown in (a), the p ₃ is formed using the Si ₃ N ₄ film 6 as a mask.
The impurity diffusion cladding layer region 10 of the (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 4 is partially etched halfway. A resist is applied from above, and is formed in a stripe shape by photolithography.
As shown in FIG. 1, a resist film 12 is formed, and the resist film 12 is used as a mask to form Si ₃ N _{4 on} both sides of the resist film 12.
By removing the film 6, the Si ₃ N ₄ film 6 is patterned in a stripe shape. Further, using the resist film 12 as an etching mask, p- (A
After forming the ridge waveguide by partially removing the l _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4, the resist film 12 is removed (FIG. 9A). In this state, the stripe-shaped Si ₃ N ₄ film 1 is located near the end face of the ridge waveguide.
3 is in a state where the crystal is exposed without being covered.

By the second crystal growth from above, FIG.
As shown in (b), a current blocking layer 14 is grown.
At this time, no crystal grows on the striped Si ₃ N ₄ film 13. After removing the stripe-shaped Si ₃ N ₄ film 13, a p-GaAs second contact layer 15 is crystal-grown in a third crystal growth (not shown), and the p-GaAs second contact is formed. A p-side electrode 17 is formed on the layer 15 by a method such as electron beam evaporation or sputtering.
By forming the n-side electrode 16 on the lower surface of the GaAs semiconductor substrate 1, the semiconductor laser diode of the second embodiment is manufactured.

In the semiconductor laser diode of the second embodiment manufactured as described above, the p- (Al
_0.7 Ga _0.3 ) _0.5 In _0.5 P
After partially etching, an n-GaAs current blocking layer 14 is provided thereon. Here, during laser oscillation, the n-GaAs current blocking layer 14 and p- (Al _0.7
Since a reverse bias to the Ga _{0.3) 0.5} In _0.5 P cladding layer 4, the p-(Al _0.7 Ga _{0.3) 0.5} In _0.5 P cladding layer 4, the n-GaAs current blocking layer 14, current does not flow. Therefore, in the vicinity of the end face of the semiconductor laser diode according to the second embodiment, as shown by the arrow in FIG. 10, the current hardly flows into the disordered active layer in the window region, whereby the reactive current can be greatly reduced. As a result, a semiconductor laser diode having a window structure with high efficiency and high output can be realized. Incidentally, as the p-type dopant of each layer in the first and second embodiments, Zn,
Mg, C and Be can be used, and Si, Se and S can be used as n-type dopants.

Modification Example In the first and second embodiments, n
-(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 2, In
_0.5 Ga _0.5 P quantum well active layer 3, p- (Al _0.7 G
Although the a _0.3 ) _0.5 In _0.5 P cladding layer 4 was used, the present invention is not limited to this, and the general formula (Al _x Ga _{1 -x} ) _y In _{1 -y} P ( Where 0.65 ≦ x
≦ 0.75, 0.45 ≦ y ≦ 0.55), and the active layer can be represented by the general formula I
A compound semiconductor represented by n _s Ga _1-s P (where 0.45 ≦ s ≦ 0.55) can be used. Even with the above configuration, the same operation and effect as those of the first and second embodiments can be obtained. Here, the reason for limiting the composition ratio as described above is that if the composition ratio of each layer is out of the above range, lattice matching with the GaAs substrate cannot be performed.

In the first and second embodiments, n-
A cladding layer 2 made of (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P; a quantum well active layer 3 made of In _0.5 Ga _0.5 P;
Cladding layer 4 made of (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P
However, the present invention is not limited thereto, and a compound semiconductor such as AlGaAs can be used as the n-type and p-type cladding layers. In this case, GaAs, Al
Compound semiconductors such as GaAs and InGaAs can be used. Embodiment 1 and Embodiment 1
It has the same function and effect as 2.

[0028]

As described above in detail, the first embodiment according to the present invention is described.
The semiconductor laser diode of the present invention includes the first cladding layer, the active layer, and the second cladding layer, and is doped with Zn in the vicinity of each of the resonance end faces to thereby activate the semiconductor in the vicinity of each of the resonance end faces. In a semiconductor laser diode having a window structure in which layers are disordered, a region doped with Si is formed in the second cladding layer near each of the resonance end faces. As a result, a high-resistance Si-doped region can be formed in the second cladding layer in the vicinity of each resonance end face, and the current flowing into the disordered active layer can be reduced. it can. Therefore, according to the present invention, the reactive current generated by the window structure can be reduced, so that a semiconductor laser diode capable of high optical output without increasing the operating current can be provided.

A second semiconductor laser diode according to the present invention includes the first cladding layer, the active layer, the second cladding layer, and the current blocking layer, and is provided near each of the resonance end faces. A semiconductor laser diode having a window structure in which the active layer near each of the resonance end faces is disordered by doping Zn, wherein the ridge portion of the first cladding layer near each of the resonance end faces is thinned, The current block layer is formed so as to cover the thinned ridge portion. Thereby, a pn junction can be formed between the second cladding layer and the current blocking layer in the vicinity of each resonance end face, and in the vicinity of each resonance end face, the pn junction can be formed from the second cladding layer to the current blocking layer. Current flowing into the disordered active layer can be reduced, and the reactive current can be reduced. Therefore, according to the present invention, the reactive current generated by the window structure can be reduced, so that a semiconductor laser diode capable of high optical output without increasing the operating current can be provided.

Further, a first method for manufacturing a semiconductor laser diode according to the present invention is a method for manufacturing a semiconductor laser diode having a window structure, the method comprising the steps of: After doping Zn in the thickness direction to the middle of the first cladding layer to disorder the active layer near each of the resonance end faces, Si is added to the second cladding layer near each of the resonance end faces. Including doping. Thereby, a high-resistance region doped with Si can be formed in the second cladding layer in the vicinity of each resonance end face, so that a semiconductor laser diode capable of high optical output without increasing operating current. Can be manufactured.

Further, in the second method of manufacturing a semiconductor laser diode according to the present invention, the ridge portion of the first cladding layer near each of the resonance end faces is thinned, and then the thinned ridge portion is covered. And growing the current blocking layer. Thereby, a semiconductor laser diode in which a pn junction is formed between the second cladding layer and the current blocking layer in the vicinity of each resonance end face can be manufactured. By blocking the current flowing into the pn junction by the pn junction, a semiconductor laser diode capable of high optical output without increasing the operating current can be manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a configuration of a semiconductor laser diode according to a first embodiment of the present invention.

FIGS. 2A and 2B are perspective views of the wafer after one step in a manufacturing process of the semiconductor laser diode according to the first embodiment;

FIGS. 3A and 3B are schematic cross-sectional views of a wafer after one step in a manufacturing process of the semiconductor laser diode according to the first embodiment, and FIG. FIG. 21 is a perspective view of the wafer after one step in the manufacturing process of FIG.

FIGS. 4A and 4B are perspective views of the wafer after one step in a manufacturing process of the semiconductor laser diode according to the first embodiment;

FIGS. 5A and 5B are perspective views of the wafer after one step in a manufacturing process of the semiconductor laser diode according to the first embodiment;

FIG. 6A is a schematic cross-sectional view of a wafer after one step in a manufacturing process of the semiconductor laser diode according to the first embodiment, and FIG. 6B is a diagram illustrating a manufacturing process of the semiconductor laser diode according to the first embodiment; It is a perspective view of the wafer after one process.

FIG. 7 is a schematic sectional view of a window structure portion in the semiconductor laser diode according to the first embodiment.

FIGS. 8A and 8B are perspective views of a wafer after one step in a manufacturing process of the semiconductor laser diode according to the second embodiment.

FIGS. 9A and 9B are perspective views of the wafer after one step in a manufacturing process of the semiconductor laser diode according to the second embodiment.

FIG. 10 is a schematic sectional view of a window structure in a semiconductor laser diode according to a second embodiment.

FIG. 11 is a perspective view schematically showing a configuration of a conventional semiconductor laser diode.

FIG. 12 is a schematic cross-sectional view of a window structure in a conventional semiconductor laser diode.

[Explanation of symbols]

1 n-GaAs substrate, 2 n- (Al _0.7 Ga _0.3 )
_0.5 In _0.5 P clad layer, 3 In _0.5 Ga _0.5 P quantum well active layer, 4 p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer, 5 p-GaAs first contact layer, 9 disordered active layer, 10 Impurity diffusion cladding layer region, 11
Si impurity diffusion region, 14 n-GaAs current blocking layer, 15 p-GaAs second contact layer, 16 n
Side electrode, 17p side electrode.

Claims (5)

[Claims] A first cladding layer made of an n-type compound semiconductor; an active layer made of a compound semiconductor grown on the first cladding layer; and a p-type compound semiconductor grown on the active layer. And a second cladding layer having a ridge portion formed from one resonance end face to the other resonance end face on the upper surface, wherein the second cladding layer is provided near each of the resonance end faces.
A semiconductor laser diode having a window structure in which the active layer near each of the resonance end faces is disordered by doping Zn in the thickness direction from the upper surface of the cladding layer to the middle of the first cladding layer. The second cladding layer near the end face is
A semiconductor laser diode, wherein a region doped with is formed. 2. A semiconductor device comprising: a first clad layer made of an n-type compound semiconductor; an active layer made of a compound semiconductor grown on the first clad layer; and a p-type compound semiconductor grown on the active layer. A second cladding layer having a ridge formed from one resonance end face to the other resonance end face on the upper surface, and an n-type compound semiconductor grown on the second cladding layer on both sides of the ridge. A current blocking layer, wherein in the vicinity of each of the resonance end faces, Zn is doped in the thickness direction from the upper surface of the second cladding layer to the middle of the first cladding layer so as to be in the vicinity of each of the resonance end faces. A semiconductor laser diode having a window structure in which an active layer is disordered, wherein the ridge portion of the second cladding layer near each of the resonance end faces is thinned, and the current block is formed so as to cover the thinned ridge portion. A semiconductor laser diode, characterized in that to form a layer. 3. The method according to claim 1, wherein the first cladding layer and the second cladding layer have a general formula (Al _x Ga _{1 -x} ) _y In _{1 -y} P (where
0.65 ≦ x ≦ 0.75, 0.45 ≦ y ≦ 0.55), and the active layer has a general formula I
3. The semiconductor laser diode according to claim 1, comprising a compound semiconductor represented by n _s Ga _1-s P (where 0.45 ≦ s ≦ 0.55). 4. A semiconductor device comprising: a first cladding layer made of an n-type compound semiconductor; an active layer made of a compound semiconductor grown on the first cladding layer; and a p-type compound semiconductor grown on the active layer. And a second cladding layer having a ridge portion formed from one resonance end face to the other resonance end face on the upper surface, the method comprising the steps of: After doping Zn in the thickness direction from the upper surface of the second cladding layer to the middle of the first cladding layer to disorder the active layer in the vicinity of each resonance facet, the active layer in the vicinity of each resonance facet is disordered. A method for manufacturing a semiconductor laser diode, comprising doping the second cladding layer with Si. 5. A semiconductor device comprising: a first clad layer made of an n-type compound semiconductor; an active layer made of a compound semiconductor grown on the first clad layer; and a p-type compound semiconductor grown on the active layer. A second cladding layer having a ridge formed from one resonance end face to the other resonance end face on the upper surface, and an n-type compound semiconductor grown on the second cladding layer on both sides of the ridge. A current blocking layer, wherein in the vicinity of each of the resonance end faces, Zn is doped in the thickness direction from the upper surface of the second cladding layer to the middle of the first cladding layer so as to be in the vicinity of each of the resonance end faces. A method of manufacturing a semiconductor laser diode having a window structure in which an active layer is disordered, comprising: reducing a ridge portion of the second cladding layer near each of the resonance end faces so as to cover the thinned ridge portion. The method of manufacturing a semiconductor laser diode, which comprises growing the serial current blocking layer.