JP2003304021A - Semiconductor laser and its manufacturing method, semiconductor light emitting element and its manufacturing method, semiconductor device and its manufacturing method, semiconductor structure and its manufacturing method, electronic device and its manufacturing method and structure and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To upgrade an end face of a resonator formed by cleavage or the flatness of the end face even when the cleavage of a substrate is poor. <P>SOLUTION: When a semiconductor laser using a III-V nitride compound semiconductor is manufactured, III-V nitride compound semiconductor layers 2, 3 are grown on different types of substrates such as, for example, a sapphire substrate 1, and then a part near the forming position of the end face of the resonator of the layers 2, 3 is separated from the substrate 1 by irradiating the substrate with an ultraviolet laser beam. Then, the layers 2, 3 are cleaved together with the substrate 1 to thereby form the end face of the resonator. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser, a method for manufacturing the same, a semiconductor light emitting element, a method for manufacturing the same, a semiconductor device, a method for manufacturing the same, a semiconductor structure, a method for manufacturing the same, an electronic device, a method for manufacturing the same, and a structure. The invention and its manufacturing method are suitable for application to, for example, a semiconductor laser or a light emitting diode using a nitride-based III-V group compound semiconductor.

[0002]

2. Description of the Related Art In recent years, as a semiconductor laser capable of emitting light from the blue region to the ultraviolet region, which is required for increasing the density of optical discs, nitride-based III-based materials such as AlGaInN
Research and development of semiconductor lasers using V-group compound semiconductors have been actively conducted. Among these semiconductor lasers, what is required to realize a high-power semiconductor laser for writing on an optical disk is a low driving current and a long life under high temperature and high output.

In the production of high-power semiconductor lasers for writing, which have been reported so far, nitride-based III- for forming a laser structure on a sapphire substrate having poor cleavage.
After the group V compound semiconductor layer is grown using the lateral crystal growth technique, these nitride-based III-V group compound semiconductor layers are cleaved together with the sapphire substrate to form the resonator end face.

An example of a GaN-based semiconductor laser manufactured by this method is shown in FIG. In FIG. 7, reference numeral 101
Is a sapphire substrate, 102 is a nitride-based III-V group compound semiconductor layer grown by a lateral crystal growth technique, 10
3 is a nitride III-V group compound semiconductor layer forming a laser structure, 104 is a ridge portion, 105 is an insulating film, 106
Is a p-side electrode, 107 is an n-side electrode, and 108 is a resonator end face formed by cleavage.

[0005]

However, in manufacturing the above-mentioned GaN-based semiconductor laser, as shown in FIG. 7, nitride-based III-V group compound semiconductor layers 102, 1 are used.
03 is periodically and physically and chemically contacted with the sapphire substrate 101 to be bonded to the sapphire substrate 1.
Since the cleaving property of 01 is poor, a large unevenness 109 is generated on the cavity facet 108 due to the influence of the cleaving, which increases the driving current of the GaN-based semiconductor laser, deteriorates the beam shape, and increases the yield. There was a problem such as a decrease in power.

As a method of solving this problem, a thick GaN layer of about 100 μm is grown on a sapphire substrate,
There is a method in which a laser structure is formed thereon and then the sapphire substrate is removed by lapping or ultraviolet irradiation. In this case, since GaN has a cleavage property, a flat resonator end face can be formed. However, this method cannot be called a practical method because it takes a lot of time to grow a thick GaN layer and it is difficult to uniformly remove the entire substrate.

The problem that unevenness is generated on the end face of the resonator is caused when the nitride-based III-V group compound semiconductor layer is grown on the sapphire substrate without using the lateral crystal growth technique as described above or other than the sapphire substrate. The same can occur when a substrate having a poor cleavage property is used. In addition, not only when the resonator end face is formed by cleavage, but generally when the end face is formed by cleavage after growing a layer on a heterogeneous substrate and the cleavage of the substrate is poor, it generally occurs. I will get it.

Therefore, the problem to be solved by the present invention is to provide a semiconductor laser and a manufacturing method thereof in which the cavity end face formed by the cleavage has a good flatness even when the cleavage of the substrate is poor. is there.

More generally, the problem to be solved by the present invention is to provide a semiconductor light emitting element and a semiconductor device in which even if the cleavage of the substrate is poor, the flatness of the end face of the semiconductor layer formed by the cleavage is good. And to provide a semiconductor structure and a manufacturing method thereof.

Furthermore, the problem to be solved by the present invention is to provide an electronic device and a structure having excellent flatness of the end face of a layer formed by cleavage even if the substrate has poor cleavage, and a method for manufacturing them. To provide.

[0011]

In order to solve the above problems, in the first invention of the present invention, a nitride-based III-V group compound semiconductor layer is different from this nitride-based III-V group compound semiconductor layer. Nitride type I laminated on a substrate made of a material
In a semiconductor laser having a cavity end face formed by cleavage in a II-V group compound semiconductor layer, a portion of the nitride-based III-V group compound semiconductor layer near the cavity end face is separated from the substrate. It is a feature.

The second invention of the present invention is the nitride-based III
After the -V group compound semiconductor layer is grown on a substrate made of a material different from that of the nitride-based III-V group compound semiconductor layer, the nitride-based III-V group compound semiconductor layer is cleaved together with the substrate to cause resonance. In a method of manufacturing a semiconductor laser in which a device end face is formed, a nitride-based III
After the growth of the group-V compound semiconductor layer and before the cleavage, the nitride-based compound II in the vicinity of the position where the cavity facet is formed is formed.
It is characterized in that the IV compound semiconductor layer is separated from the substrate.

Here, "peeling" means a nitride-based III-
It means that the bond by physical and chemical contact between the group V compound semiconductor layer and the substrate is substantially eliminated,
This is not necessarily the case where a physical gap is clearly present between the nitride-based III-V group compound semiconductor layer and the substrate (the same applies hereinafter).

In the first aspect of the present invention, the width of the portion of the nitride-based III-V compound semiconductor layer separated from the substrate in the cavity length direction measured from the cavity end face is generally the resonance. If the length exceeds about 20%, the bond due to physical and chemical contact with the substrate becomes too weak, and the entire nitride-based III-V group compound semiconductor layer easily peels off from the substrate, resulting in reliability of the semiconductor laser. However, if it is about 5 μm or less, it becomes difficult to perform alignment during cleavage. Therefore, in consideration of these matters, generally 5 μm or more and 0.2 L μm (where L is Resonator length in μm) or less. This width is, for example, 5 μm or more and 100 μm or less, and preferably 5 μm or more and 50 μm or less, although it depends on the resonator length. Correspondingly, in the second invention of the present invention, the width for peeling the nitride III-V compound semiconductor layer from the substrate is generally 10 μm or more and 0.4 L μm (where L is expressed in μm). Resonator length) or less, specifically, 10 μm or more and 200 μm or less, preferably 10 μm or more and 100 μm or less. The cleavability of the substrate is usually worse than that of the nitride-based III-V compound semiconductor layer, and the sapphire substrate is a typical example of such a substrate.

In the second aspect of the present invention, the peeling of the nitride III-V group compound semiconductor layer from the substrate is typically performed by applying a thermal stimulus by heating. For example, laser light having a wavelength that is absorbed by the nitride-based III-V compound semiconductor layer is applied to a portion near the position where the cavity facet is formed. More specifically, nitride-based III-
Laser light having a wavelength that is absorbed by the group V compound semiconductor layer and that is transmitted through the substrate is irradiated from a rear surface side of the substrate to a portion in the vicinity of the position where the resonator end face is formed. At this time, the laser light passes through the substrate and is irradiated onto the nitride-based III-V group compound semiconductor layer, thereby heating the vicinity of the interface with the substrate and, as a result, the portion near the formation position of the cavity facet The nitride-based III-V group compound semiconductor layer is separated from the substrate. This laser light is typically ultraviolet laser light, and may be continuous wave or pulsed. As such a laser light source, specifically, for example, an excimer laser, particularly ArF (wavelength 193 nm),
KrCl (wavelength 222nm), KrF (wavelength 248n)
m), XeCl (wavelength 308 nm), XeF (wavelength 35)
1nm) rare gas halide excimer laser, nitrogen laser (wavelength 337.1nm), YAG laser (third harmonic (wavelength 355nm), fourth harmonic (wavelength 266n)
m)) and the like.

The nitride III-V compound semiconductors, Ga most commonly _{Al X B y 1-xy- z} In z As u N
_1-uv P _v (where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z
≦ 1, 0 ≦ u ≦ 1, 0 ≦ v ≦ 1, 0 ≦ x + y + z <1,
0 ≦ u + v consists <1), more specifically Al _X B _y
Ga _1-xyz In _z N (where 0 ≦ x ≦ 1, 0 ≦ y ≦
1, 0 ≦ z ≦ 1, 0 ≦ x + y + z <1), and is typically Al _X Ga _1-xz In _z N (where 0 ≦ x ≦
1, 0 ≦ z ≦ 1). Specific examples of the nitride-based III-V group compound semiconductor include GaN, InN, and Al.
N, AlGaN, InGaN, AlGaInN and the like.

According to a third aspect of the present invention, in a semiconductor laser in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and a cavity end face is formed in the semiconductor layer by cleavage, It is characterized in that a portion near the end face of the resonator is separated from the substrate.

According to a fourth aspect of the present invention, after the semiconductor layer is grown on a substrate made of a material different from that of the semiconductor layer,
In a method of manufacturing a semiconductor laser in which a cavity facet is formed by cleaving this semiconductor layer together with a substrate, after the semiconductor layer is grown, before cleaving, a portion in the vicinity of the cavity end face formation position is formed. The semiconductor layer is separated from the substrate.

According to a fifth aspect of the present invention, in a semiconductor light emitting device in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and an end face is formed by cleavage in the semiconductor layer, an end face of the semiconductor layer is formed. Is characterized in that a portion in the vicinity of is separated from the substrate.

According to a sixth aspect of the present invention, after the semiconductor layer is grown on a substrate made of a material different from that of the semiconductor layer,
In a method for manufacturing a semiconductor light-emitting device in which an end face is formed by cleaving this semiconductor layer together with a substrate, a semiconductor layer in the vicinity of the position where the end face is formed is grown after the semiconductor layer is grown and before the cleavage. Is separated from the substrate.

According to a seventh aspect of the present invention, in a semiconductor device in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer and an end face is formed in the semiconductor layer by cleavage, It is characterized in that a nearby portion is separated from the substrate.

According to an eighth aspect of the present invention, after growing a semiconductor layer on a substrate made of a material different from that of the semiconductor layer,
In a method of manufacturing a semiconductor device in which an end face is formed by cleaving this semiconductor layer together with a substrate, after the semiconductor layer is grown, before the cleavage, the semiconductor layer in the vicinity of the position where the end face is formed is removed. It is characterized in that it is peeled off from the substrate.

According to a ninth aspect of the present invention, in a semiconductor structure in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and an end face is formed on the semiconductor layer, the vicinity of the end face of the semiconductor layer is provided. The part is peeled off from the substrate.

A tenth aspect of the present invention is a semiconductor structure in which a semiconductor layer is grown on a substrate made of a material different from that of the semiconductor layer, and the semiconductor layer is cleaved together with the substrate to form an end face. In the method for manufacturing a body, after the semiconductor layer is grown, before the cleavage, the semiconductor layer in the vicinity of the position where the end face is formed is peeled off from the substrate.

In the third to tenth aspects of the present invention,
The semiconductor layer may be basically any kind as long as it is difficult to obtain an end face with good flatness when cleaved together with the substrate, but typically, it is grown on a heterogeneous substrate. This is the case where the substrate is poor in the cleavability. The semiconductor layer is specifically, for example, nitride-based I
In addition to II-V group compound semiconductors, various III-V group compound semiconductors such as AlGaAs series semiconductors, AlGaInP series semiconductors, InGaAsP series semiconductors and GaInNAs series semiconductors, and II-VI group compounds such as ZnSe series semiconductors and ZnO series semiconductors It is a layer such as a semiconductor. Also,
What has been described in connection with the first and second inventions of the present invention is the third to tenth inventions of the present invention unless it is contrary to the nature thereof.
The invention also holds.

In the third to tenth aspects of the present invention,
The semiconductor light emitting element includes a light emitting diode and a semiconductor laser, and the semiconductor device includes, in addition to these semiconductor light emitting elements, a light receiving element, a field effect transistor (FET) such as a high electron mobility transistor, and a heterojunction bipolar transistor. An electronic transit device such as (HBT) is included.

An eleventh aspect of the present invention is an electronic device in which a layer is laminated on a substrate made of a substance different from this layer, and an end face is formed in the layer by cleavage, and a portion of the layer near the end face is It is characterized in that it is separated from the substrate.

A twelfth invention of the present invention is a method of manufacturing an electronic device, wherein an end face is formed by growing a layer on a substrate made of a substance different from this layer and cleaving this layer together with the substrate. In the above method, after the layer is grown, before the cleavage, the layer in the vicinity of the position where the end face is formed is peeled from the substrate.

In a thirteenth aspect of the present invention, in a structure in which a layer is laminated on a substrate made of a substance different from this layer and an end face is formed on the layer, a portion of the layer near the end face is separated from the substrate. It is characterized by being peeled off.

A fourteenth invention of the present invention is a method for manufacturing a structure, wherein an end face is formed by growing a layer on a substrate made of a substance different from this layer and cleaving this layer together with the substrate. In the above method, after the layer is grown, before the cleavage, the layer in the vicinity of the position where the end face is formed is peeled from the substrate.

In the eleventh to fourteenth aspects of the present invention, the layer is basically of any type as long as it is difficult to obtain an end face having good flatness when cleaved together with the substrate. However, it is typically a case where the substrate is grown on a heterogeneous substrate and the cleavage of the substrate is poor. When the electronic device is a semiconductor laser, a semiconductor light emitting element, a semiconductor device, a semiconductor structure, etc., this layer is, for example, various semiconductor layers as described above, and the electronic device is a piezoelectric element, a pyroelectric element, an optical element ( When it is a second harmonic generation element using a nonlinear optical crystal), a dielectric element (including a ferroelectric element), a superconducting element, etc., it is a layer of various materials such as oxide. For oxide materials,
For example, Journal of the Society of Japan Vol.103, No.1
1 (1995) pp.1099-1111 and Materials Science and Engine
There are many, such as those disclosed in ering B41 (1996) 166-173. Further, what has been described in relation to the first and second inventions of the present invention is also valid in the eleventh to fourteenth inventions of the present invention as long as the characteristics thereof are not violated.

In the present invention, the substrate is specifically
For example, in addition to a sapphire substrate, a SiC substrate, a Si substrate, a GaAs substrate, a GaP substrate, an InP substrate, a spinel substrate, a silicon oxide substrate, a ZnO substrate, and the like.

The growth method of the nitride-based III-V group compound semiconductor and other semiconductor layers is, for example, metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxial growth or halide vapor phase epitaxial growth (HVPE). In addition, molecular beam epitaxy (MB
E) or the like can be used.

According to the present invention configured as described above, the nitride-based III-V compound semiconductor layer or the semiconductor layer or layer in the vicinity of the cavity facet or the position where the facet is formed is formed before the cleavage. To separate from the substrate,
Even if the cleaving property of the substrate is poor, the influence is not exerted at the time of cleaving, and it is possible to prevent generation of streaky unevenness on the resonator end face or the end face.

[0035]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In all the drawings of the embodiments, the same or corresponding parts are designated by the same reference numerals. 1 to 5 show Ga according to an embodiment of the present invention.
An N-type semiconductor laser (chip state) is shown. Here, FIG.
Is a plan view, FIG. 2 is an enlarged sectional view taken along line II-II of FIG. 1, FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 1, and FIG. 4 is line IV-IV of FIG. FIG. 5 is an enlarged cross-sectional view taken along, and FIG. 5 is an enlarged side view showing one resonator end face.
This GaN semiconductor laser has a ridge structure and an SCH.
(Separate Confinement Heterostructure) structure.

As shown in FIGS. 1 to 5, in the GaN-based semiconductor laser according to this embodiment, ELO is formed on a c-plane sapphire substrate 1 via an undoped GaN buffer layer (not shown) grown by low temperature. (Epitaxial Latera
An undoped GaN layer 2 grown using a lateral crystal growth technique such as l Overgrowth) is laminated. Then, a GaN-based semiconductor layer 3 forming a laser structure is stacked on the undoped GaN layer 2. In particular,
As the GaN-based semiconductor layer 3, for example, an n-type GaN contact layer, an n-type AlGaN cladding layer, an n-type GaN optical waveguide layer, for example, undoped In _x Ga _1-x N / In _y Ga.
_1-y N multiple quantum well active layer, AlGaN / GaN
Superlattice cap layer, p-type GaN optical waveguide layer, p-type AlGa
An N / GaN superlattice cladding layer and a p-type GaN contact layer are sequentially stacked.

Here, the undoped GaN buffer layer is thick.
Is, for example, 30 nm. Undoped GaN layer 2 is thick
Is, for example, 0.5 μm. n-type GaN contact layer
Has a thickness of, for example, 4 μm.
It is doped with silicon (Si). n-type AlGaN
The clad layer has a thickness of, for example, 1.0 μm, and has an n-type impurity
For example, Si is doped, and the Al composition is
It is 0.07. The n-type GaN optical waveguide layer has a thickness of, for example,
0.1 μm, and, for example, Si is used as an n-type impurity.
Have been In addition, undoped In_xGa_1-xN / I
n_yGa_1-yThe active layer of the N multiple quantum well structure is a barrier layer.
Then In_xGa_1-xIn as N layer and well layer_yGa
_1-yA layer in which N layers are alternately laminated, for example, a barrier layer
In as _xGa_1-xWhen the thickness of the N layer is 7 nm, x = 0.
02, In as a well layer_yGa_1-yThe thickness of the N layer is 3.
At 5 nm, y = 0.14 and the number of wells is 3.

The AlGaN / GaN superlattice cap layer is
For example, an undoped AlGaN layer having a thickness of 2.5 nm and an Al composition of 0.18 is used as a barrier layer, and a GaN layer having a thickness of 2.5 nm and doped with, for example, Mg as a p-type impurity is used as a well layer. It has a structure in which these are alternately laminated, and the total thickness of the AlGaN layer as the barrier layer is, for example, 100 nm. This AlGaN / GaN superlattice cap layer is a p-type GaN optical waveguide layer, p-type AlGaN /
This is for preventing In from desorbing from the active layer and deteriorating during the growth of the GaN superlattice cladding layer and the p-type GaN contact layer, and at the same time preventing the overflow of electrons from the active layer.

The p-type GaN optical waveguide layer has a thickness of, for example, 0.1.
μm, and is doped with, for example, Mg as a p-type impurity. The p-type AlGaN / GaN superlattice cladding layer is
For example, an undoped AlGaN layer having a thickness of 2.5 nm and an Al composition of 0.12 is used as a barrier layer, and a Mg-doped GaN layer having the same thickness of 2.5 nm is used as a well layer, and these layers are alternately stacked. The total thickness is, for example, 0.5 μm. The p-type GaN contact layer has a thickness of, for example, 0.1 μm, and is doped with, for example, Mg as a p-type impurity.

Of the GaN-based semiconductor layer 3, the upper layer of the n-type GaN contact layer, the n-type AlGaN cladding layer, the n-type GaN optical waveguide layer, the active layer, the AlGaN / GaN superlattice cap layer, and the p-type GaN optical waveguide layer. And p-type AlGaN /
The GaN superlattice cladding layer has a mesa shape with a predetermined width.
A ridge portion 4 extending in the <1-100> direction, for example, is formed in the upper layer portion of the p-type AlGaN / GaN superlattice cladding layer and the p-type GaN contact layer in the mesa portion. The width of this ridge portion 4 is, for example, 3 μm.

On the above mesa portion, for example, a thickness of 0.3 μm
An insulating film 5 such as a SiO ₂ film of m is provided. An opening is provided in a portion of the insulating film 5 on the ridge portion 5, and the p-side electrode 6 is in contact with the uppermost p-type GaN contact layer of the GaN-based semiconductor layer 3 through the opening. . The p-side electrode 6 has a structure in which, for example, a Pd film, a Pt film, and an Au film are sequentially stacked, and the Pd film, the Pt film, and the Au film have thicknesses of 10 nm and 100 n, respectively.
m and 300 nm. On the other hand, the n-side electrode 7 is in contact with the lowermost n-type GaN contact layer of the GaN-based semiconductor layer 3 in a predetermined portion adjacent to the mesa portion. The n-side electrode 7 has a structure in which, for example, a Ti film, a Pt film, and an Au film are sequentially stacked, and the thicknesses of the Ti film, the Pt film, and the Au film are, for example, 10 nm, 50 nm, and 100 nm, respectively.

In this GaN-based semiconductor laser, portions of the undoped GaN layer 2 and the GaN-based semiconductor layer 3 having a predetermined width W from the cavity end faces 8 and 9 are separated from the c-plane sapphire substrate 1 and are separated from each other. An extremely narrow gap is formed between them, and the other portions are periodically in physical contact with and bonded to the c-plane sapphire substrate 1. Here, the width W is 5 μm or more and 100 μm or less,
For example, it is about 20 μm. The resonator length L is, for example, about 600 μm.

Next, a method of manufacturing the GaN-based semiconductor laser according to this embodiment will be described. First, the surface of which was previously cleaned by thermal cleaning or the like c
For example, 50 on the surface sapphire substrate 1 by the MOCVD method.
After growing the undoped GaN buffer layer at a temperature of about 0 ° C., the undoped GaN layer 2 is grown at a growth temperature of, for example, 1000 ° C. using a lateral crystal growth technique such as ELO.

Subsequently, M is formed on the undoped GaN layer 2.
A GaN-based semiconductor layer 3 forming a laser structure by the OCVD method, specifically, for example, an n-type GaN contact layer, an n-type AlGaN cladding layer, an n-type GaN optical waveguide layer,
Undoped Ga _1-x In _x N / Ga _1-y In _y N multiple quantum well structure active layer, AlGaN / GaN superlattice cap layer, p-type GaN optical waveguide layer, p-type AlGaN / GaN
A superlattice cladding layer and a p-type GaN contact layer are sequentially grown. Here, the growth temperature of these layers is, for example, 1000 ° C. from the n-type GaN contact layer to the n-type GaN optical waveguide layer, 780 ° C. from the active layer to the p-type GaN optical waveguide layer, and p-type AlGaN / GaN The temperature of the lattice clad layer and the p-type GaN contact layer is 1000 ° C.

The growth materials for these GaN-based semiconductor layers are
For example, as a Ga raw material, trimethylgallium ((C
H ₃ ) ₃ Ga, TMG), trimethyl aluminum ((CH ₃ ) ₃ Al, TMA) as a raw material for Al, and trimethyl indium ((CH ₃ ) ₃ I as a raw material for In.
n, TMI), and NH ₃ as a raw material of N. Regarding the dopant, for example, silane (SiH ₄ ) is used as the n-type dopant, and bis = methylcyclopentadienyl magnesium ((CH
₃ C ₅ H ₄ ) ₂ Mg) or bis = cyclopentadienyl magnesium ((C ₅ H ₅ ) ₂ Mg) is used.

During the growth of these GaN-based semiconductor layers
N-type GaN contact
From the layer to the n-type GaN optical waveguide layer is N₂And H₂Mixed with
, Active layer and AlGaN / GaN superlattice cap layer
Is N₂Gas atmosphere, p-type GaN optical waveguide layer to p-type GaN
N up to contact layer₂And H₂A mixed gas with is used.
In this case, after growing the active layer, AlGaN / GaN
The carrier gas atmosphere is set to N until the superlattice cap layer is grown.
₂The atmosphere is H and the carrier gas atmosphere is H ₂Contains
Therefore, it is necessary to suppress the desorption of In from the active layer.
Therefore, deterioration of the active layer can be prevented. Also,
From p-type GaN optical waveguide layer to p-type GaN contact layer
The carrier gas atmosphere is N₂And H₂Mixed with
The p-type layer has a good crystal quality because of the atmosphere.
Can be grown in sex.

Next, the c-plane sapphire substrate 1 on which the GaN-based semiconductor layer 3 has been grown as described above is taken out from the MOCVD apparatus. Then, the p-type Al of the GaN-based semiconductor layer 3
The ridge portion 6 is formed by selectively etching the GaN / GaN superlattice cladding layer to a predetermined depth in the thickness direction by a reactive ion etching (RIE) method.

Next, after forming the insulating film 5 on the entire surface of the substrate,
This is patterned into a predetermined shape by etching.
Next, using this insulating film 5 as a mask, Ga is formed by the RIE method.
Etching is performed until the n-type GaN contact layer of the N-based semiconductor layer 3 is reached. By this etching, the n-type GaN contact layer, which is an upper layer portion of the GaN-based semiconductor layer 3,
-Type AlGaN cladding layer, n-type GaN optical waveguide layer, active layer, AlGaN / GaN superlattice cap layer, p-type GaN
The optical waveguide layer, the p-type AlGaN / GaN superlattice cladding layer and the p-type GaN contact layer are patterned into a mesa shape.

Next, Ti / Pt / on the n-type GaN contact layer of the GaN-based semiconductor layer 3 in the portion adjacent to the mesa portion.
An n-side electrode 7 having an Au structure is formed.

Next, the insulating film 5 on the ridge portion 4 is removed by etching to form an opening, and then P is formed on the p-type GaN contact layer of the GaN-based semiconductor layer 3 through this opening.
A p-side electrode 6 having a d / Pt / Au structure is formed.

Next, as shown in FIG. 6, from the back surface side of the c-plane sapphire substrate 1 having the laser structure formed as described above, linearly along the position where the cavity end face is formed by cleavage, The c-plane sapphire substrate 1 is irradiated with transparent ultraviolet laser light. The width of this ultraviolet laser light irradiation region 10 (the hatched region in FIG. 6) is 2W. Here, as the ultraviolet laser light, for example, pulsed laser light from an excimer laser is used, and the irradiation energy density is, for example, several mJ / cm ² depending on the type of the excimer laser.
Up to several hundred mJ / cm ² . This ultraviolet laser light is c
Since it is transparent to the plane sapphire substrate 1, it is transmitted through the c-plane sapphire substrate 1 and irradiated onto the undoped GaN layer 2 to be absorbed. As a result, the c-plane sapphire substrate 1 and the undoped GaN layer 2 in the portion irradiated with the ultraviolet laser light
The interface with and is heated, and due to the thermal stimulus caused by it, only the undoped GaN layer 2 in this irradiated portion is separated from the c-plane sapphire substrate 1.

After that, the c-plane sapphire substrate 1 on which the laser structure is formed as described above is processed into a bar shape by cleavage to form both resonator end faces 8 and 9. FIG. 5 shows the resonator end face 8 thus obtained, but the resonator end face 8 is not provided with the streak-shaped irregularities that have been conventionally seen.
The same applies to the other resonator end face 9. Next, after applying end face coating to these resonator end faces 8 and 9,
This bar is made into chips by cleavage or the like. From the above,
GaN having desired ridge structure and SCH structure
System semiconductor laser is manufactured.

As described above, according to this embodiment,
After growing the undoped GaN layer 2 and the GaN-based semiconductor layer 3 forming the laser structure on the c-plane sapphire substrate 1, before cleaving, the undoped GaN layer 2 in the vicinity of the position where the cleavage plane is formed is c The width of the surface sapphire substrate 1 is 2 W by irradiating with ultraviolet laser light from the back surface side and heating.
Since the cleaved sapphire substrate 1 is poorly cleaved, it is not affected by the cleaving of the c-plane sapphire substrate 1 because the resonator end faces 8 and 9 are formed by preliminarily exfoliating and cleaving. It is possible to prevent streaky irregularities from being generated on the cavity end faces 8 and 9, and it is possible to obtain the cavity end faces 8 and 9 having good flatness. Therefore, G due to the generation of streaky unevenness on the resonator end faces 8 and 9
It is possible to prevent the drive current of the aN semiconductor laser from increasing, the beam shape from deteriorating, and the yield from decreasing.

Also, what is peeled from the c-plane sapphire substrate 1 is undoped G near the resonator end faces 8 and 9.
Only the aN layer 2 and the GaN-based semiconductor layer 3, and the undoped GaN layer 2 and the GaN-based semiconductor layer 3 in the other portions are physically and chemically contacted and bonded to the c-plane sapphire substrate 1. GaN layer 2 and GaN
It is possible to prevent the entire system semiconductor layer 3 from peeling from the c-plane sapphire substrate 1. Furthermore, since the area of the irradiation region of the ultraviolet laser light is small, the irradiation of the ultraviolet laser light can be easily performed.

Although one embodiment of the present invention has been specifically described above, the present invention is not limited to the above embodiment, and various modifications can be made based on the technical idea of the present invention. .

For example, the numerical values, structures, shapes, substrates, raw materials, processes, etc., mentioned in the above-mentioned embodiment are merely examples, and numerical values different from these, if necessary,
Structures, shapes, substrates, materials, processes, etc. may be used. Specifically, for example, the c-plane sapphire substrate is used in the above-described embodiment, but another substrate may be used as necessary.

Further, in the above-described one embodiment, the case where the present invention is applied to the SCH-based GaN-based semiconductor laser has been described. However, the present invention can be applied to, for example, DH (Do
It may be applied not only to a GaN-based semiconductor laser having a uble heterostructure) structure but also to a GaN-based light emitting diode.

[0058]

As described above, according to the present invention, a nitride-based III-V group compound semiconductor layer or a resonator of a semiconductor layer or layers is formed before forming a resonator end surface or an end surface by cleavage. By peeling the end face or the part near the position where the end face is formed from the substrate,
Even if the cleaving property of the substrate is poor, it is possible to prevent generation of streaky unevenness on the resonator end face or end face formed by cleaving, and obtain a resonator end face or end face with good flatness. be able to.

[Brief description of drawings]

FIG. 1 is a plan view showing a GaN semiconductor laser according to an embodiment of the present invention.

2 is a II-II of the GaN-based semiconductor laser shown in FIG.
It is an expanded sectional view along a line.

FIG. 3 is a III-I of the GaN-based semiconductor laser shown in FIG.
It is an expanded sectional view along a II line.

4 is a IV-IV of the GaN-based semiconductor laser shown in FIG.
It is an expanded sectional view along a line.

5 is an enlarged side view of the GaN-based semiconductor laser shown in FIG.

FIG. 6 is a plan view illustrating the method for manufacturing the GaN-based semiconductor laser according to the embodiment of the present invention.

FIG. 7 is a side view of a conventional GaN semiconductor laser.

[Explanation of symbols]

1 ... c-plane sapphire substrate, 2 ... undoped Ga
N layer, 3 ... GaN-based semiconductor layer, 8, 9 ... Resonator end face

   ─────────────────────────────────────────────────── ─── Continued front page    (54) [Title of Invention] Semiconductor laser, manufacturing method thereof, semiconductor light emitting element, manufacturing method thereof, and semiconductor device                     Device and its manufacturing method, semiconductor structure, its manufacturing method, electronic device and its manufacturing                     Manufacturing method, structure and manufacturing method thereof

Claims (20)

[Claims] 1. A nitride-based III-V group compound semiconductor layer is laminated on a substrate made of a material different from that of the nitride-based III-V group compound semiconductor layer to form the nitride-based III-V group compound semiconductor layer. A semiconductor laser having a cavity end face formed by cleavage, wherein a portion of the nitride-based III-V group compound semiconductor layer near the cavity end face is separated from the substrate. . 2. The width of the portion of the nitride-based III-V group compound semiconductor layer separated from the substrate in the cavity length direction is 5 μm or more and 0.2 Lμm (where L is a resonance expressed in μm). The length is less than or equal to
The semiconductor laser described. 3. The width of the portion of the nitride-based III-V compound semiconductor layer separated from the substrate in the cavity length direction is 5 μm or more and 100 μm or less. Semiconductor laser. 4. The semiconductor laser according to claim 1, wherein the substrate is a sapphire substrate. 5. The nitride-based III-V compound semiconductor layer is grown on a substrate made of a material different from that of the nitride-based III-V compound semiconductor layer, and then the nitride-based III-V compound semiconductor layer is grown.
In a method of manufacturing a semiconductor laser in which a cavity facet is formed by cleaving a group V compound semiconductor layer together with the substrate, the cleavage is performed after the nitride-based III-V group compound semiconductor layer is grown. A method of manufacturing a semiconductor laser, characterized in that the nitride-based III-V group compound semiconductor layer in a portion near a position where the cavity facet is formed is peeled off from the substrate. 6. A laser beam having a wavelength absorbed by the nitride-based III-V group compound semiconductor layer is irradiated to a portion near the formation position of the resonator end face, thereby forming a portion near the formation position of the resonator end face. 6. The method for manufacturing a semiconductor laser according to claim 5, wherein the nitride-based III-V group compound semiconductor layer in the portion of is separated from the substrate. 7. A laser beam having a wavelength absorbed by the nitride-based III-V compound semiconductor layer and transmitted through the substrate is irradiated from a back surface side of the substrate to a portion in the vicinity of a position where the resonator end face is formed. 6. The method for manufacturing a semiconductor laser according to claim 5, wherein the nitride-based III-V group compound semiconductor layer in a portion near a position where the cavity facet is formed is peeled off from the substrate. 8. The method of manufacturing a semiconductor laser according to claim 7, wherein the laser light is ultraviolet laser light. 9. A semiconductor laser in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and a cavity end face is formed in the semiconductor layer by cleavage, wherein the cavity end face of the semiconductor layer is A semiconductor laser, wherein a portion in the vicinity is separated from the substrate. 10. A method of manufacturing a semiconductor laser, wherein a semiconductor end face is formed by growing a semiconductor layer on a substrate made of a material different from that of the semiconductor layer and cleaving the semiconductor layer together with the substrate. After the growth of the semiconductor layer and before the cleavage, the semiconductor layer in the vicinity of the position where the cavity facets are formed is separated from the substrate. Method. 11. A semiconductor light emitting device in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and an end face is formed in the semiconductor layer by cleavage, in a portion of the semiconductor layer near the end face. Is peeled off from the substrate. 12. A method of manufacturing a semiconductor light emitting device, comprising: growing a semiconductor layer on a substrate made of a material different from that of the semiconductor layer, and then cleaving the semiconductor layer together with the substrate to form an end face. A method for manufacturing a semiconductor light emitting device, characterized in that, after growing the semiconductor layer, before performing the cleavage, the semiconductor layer in the vicinity of the position where the end face is formed is peeled from the substrate. 13. A semiconductor device in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and an end face is formed in the semiconductor layer by cleavage, wherein a portion of the semiconductor layer near the end face is A semiconductor device, which is separated from the substrate. 14. A method of manufacturing a semiconductor device, wherein an end face is formed by growing a semiconductor layer on a substrate made of a material different from that of the semiconductor layer, and cleaving the semiconductor layer together with the substrate. A method for manufacturing a semiconductor device, wherein after the semiconductor layer is grown, before the cleavage, the portion of the semiconductor layer in the vicinity of the position where the end face is formed is separated from the substrate. 15. A semiconductor structure in which a semiconductor layer is laminated on a substrate made of a material different from that of the semiconductor layer, and an end face is formed on the semiconductor layer, wherein a portion of the semiconductor layer near the end face is the above-mentioned portion. A semiconductor structure characterized by being separated from a substrate. 16. A method of manufacturing a semiconductor structure, wherein an end face is formed by growing a semiconductor layer on a substrate made of a material different from that of the semiconductor layer and cleaving the semiconductor layer together with the substrate, A method for manufacturing a semiconductor structure, wherein after the semiconductor layer is grown, before the cleavage is performed, the semiconductor layer in the vicinity of the position where the end face is formed is peeled from the substrate. 17. An electronic device in which a layer is laminated on a substrate made of a substance different from this layer, and an end face is formed on the layer by cleavage, wherein a portion of the layer near the end face is separated from the substrate. An electronic device characterized by being. 18. A method for manufacturing an electronic device, comprising: growing a layer on a substrate made of a material different from that of the layer, and then cleaving the layer together with the substrate to form an end face. After that, before performing the cleavage, the method for producing an electronic device is characterized in that the layer in the vicinity of the position where the end face is formed is peeled off from the substrate. 19. In a structure in which a layer is laminated on a substrate made of a material different from that of the layer, and an end face is formed on the layer, a portion of the layer near the end face is separated from the substrate. A structure characterized by being present. 20. A method of manufacturing a structure, wherein a layer is grown on a substrate made of a material different from that of the layer, and then the layer is cleaved together with the substrate to form an end face. After that, before the cleavage, the layer in the vicinity of the position where the end face is formed is peeled off from the substrate.