JP3375119B2 - Semiconductor crystal growth method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor crystal growth method, which is preferably used for manufacturing semiconductor light emitting devices such as semiconductor laser devices and light emitting diodes.

[0002]

2. Description of the Related Art In recent years, in the manufacture of semiconductor light emitting devices, device characteristics and yield have been improved. Therefore, it is an important issue to reduce mount distortion and mount leak that occur when the semiconductor light emitting device is mounted on the stem. In order to solve this problem, it is necessary to provide a distance between the light emitting portion of the semiconductor light emitting element and the mount base of the stem, and in order to realize this, the contact layer is provided above the light emitting portion. Is effective.

FIG. 12 shows a conventional ridge type AlGaInP.
A manufacturing process of a semiconductor laser diode device will be described.

First, as shown in FIG. 12A, a portion of the semiconductor laminated structure below the contact layer 112 is formed. That is, on the first conductivity type GaAs substrate 101, the first conductivity type GaAs buffer layer 102, the first conductivity type GaInP buffer layer 103, and the first conductivity type AlG.
aInP first clad layer 104, GaInP active layer 10
5, the second conductivity type AlGaInP second clad layer 106 and the GaInP etch stop layer 107 are formed, and the second conductivity type AlGaInP third clad layer 108, the second conductivity type GaInP intermediate layer 109 and the second
The conductive type GaAs cap layer 110 is formed in a ridge shape,
First conductivity type GaA so as to embed them on both sides thereof.
The s current confinement layer 111 is formed. At this time, the GaAs layer corresponding to the current path is exposed on the surface.

On top of that, as shown in FIG.
BE (Molecular Beam Epitax)
The second conductivity type GaAs contact layer 112 is grown by the y) method to obtain a semiconductor laminated structure.

After that, the electrode 1 is formed on the contact layer 112.
14 is formed, and the electrode 115 is formed on the substrate side.

FIG. 13 shows a conventional ridge type AlGaI.
Another manufacturing process of the nP-based semiconductor laser device is shown.

First, as shown in FIG. 13A, a portion of the semiconductor laminated structure below the contact layer 112 is formed. That is, on the first conductivity type GaAs substrate 101, the first conductivity type GaAs buffer layer 102, the first conductivity type GaInP buffer layer 103, and the first conductivity type AlG.
aInP first clad layer 104, GaInP active layer 10
5, a second conductivity type AlGaInP second clad layer 106 and a GaInP etch stop layer 107 are formed, and a second conductivity type AlGaInP third clad layer 108 and a second conductivity type GaInP intermediate layer 109 are formed in a ridge shape on the central portion thereof. And the first conductivity type GaAs current confinement layer 111 is formed so as to fill them on both sides. At this time, the GaInP layer corresponding to the current path is exposed on the surface.

Further, as shown in FIG. 13 (b), M
The second conductivity type GaAs contact layer 112 is grown by the BE method to obtain a semiconductor laminated structure.

After that, the electrode 1 is formed on the contact layer 112.
14 is formed, and the electrode 115 is formed on the substrate side.

In the semiconductor laser device thus obtained, since the second conductivity type GaAs contact layer 112 is provided on the first conductivity type GaAs current confinement layer 111, the semiconductor layer is formed from the active layer 105 which is the light emitting portion. A distance can be provided to the surface of the laminated structure. Therefore, the distance between the light emitting portion of the semiconductor laser device and the mount base of the stem can be increased to reduce mount distortion and mount leak.

[0012]

However, as shown in FIG.
In the manufacturing process of the conventional semiconductor laser device shown in FIG. 1, before the second conductivity type contact layer 112 is grown by the MBE method, the second conductivity type GaAs corresponding to the current path is formed.
The surface of the cap layer 110 is once exposed to the atmosphere. Therefore, the surface of the second-conductivity-type GaAs cap layer 110 is transformed, oxidized, or contaminated, so that the second-conductivity-type GaAs cap layer 110 and the second-conductivity-type GaAs contact layer 112 are separated from each other. A good interface cannot be obtained between them. As a result, the operating voltage of the semiconductor laser device may be as high as 3V to 4V, and the yield is poor.

Also in the manufacturing process of the conventional semiconductor laser device shown in FIG. 13, the second conductivity type contact layer 1 is also used.
Before growing 12 by the MBE method, the surface of the second conductivity type GaInP intermediate layer 109 corresponding to the current path was once exposed to the atmosphere, so that there was a similar problem.

Further, as the second conductivity type contact layer,
AlGaAs layer, GaInP layer, Al other than GaAs layer
A GaInP layer, an AlInP layer, or the like may be used, but in that case, the same problem occurs.

The present invention has been made in order to solve the problems of the prior art, and an object thereof is to provide a semiconductor crystal growth method capable of growing a semiconductor crystal in a good state by the MBE method. And

[0016]

According to the method for growing a semiconductor crystal of the present invention, Moleccu is formed on a GaAs layer or a GaInP layer provided on a light emitting portion made of a compound semiconductor layer.
by lar beam epitaxy method,
AlGaAs, GaInP, AlGaInP or Al
A method for growing a crystal of InP, comprising:
The s layer or the GaInP layer is 100 in the thickness direction from the surface.
A step of etching and removing the angstrom or more;
GaAs, AlGaAs, GaInP, Al are formed on the surface of the aAs layer or the GaInP layer after being removed by etching.
A step of growing a crystal of GaInP or AlInP, whereby the above object is achieved.

According to the method for growing a semiconductor crystal of the present invention, a molecular beam epitaxy is formed on a GaAs layer provided on a light emitting portion made of a compound semiconductor layer.
Is a method of growing a crystal of GaAs or AlGaAs by the method of irradiating the surface of the GaAs layer with an As beam at a substrate temperature of 620 ° C. or higher and 700 ° C. or lower.
The above-mentioned object is achieved by including a step of holding for more than a minute and a step of growing a crystal of GaAs or AlGaAs on the surface of the GaAs layer after the above step.

According to the method for growing a semiconductor crystal of the present invention, a molecular beam epitaxy is formed on a GaAs layer provided on a light emitting portion made of a compound semiconductor layer.
Method, GaInP, AlGaInP or AlInP
And a substrate temperature of 620 ° C. or higher while irradiating the surface of the GaAs layer with a P beam.
A step of holding at 00 ° C. or lower for 5 minutes or more, and after the above steps, GaInP and AlGaInP are formed on the surface of the GaAs layer.
Or a step of growing a crystal made of AlInP, whereby the above object is achieved.

According to the method for growing a semiconductor crystal of the present invention, a molecular beam epitaxy is formed on a GaInP layer provided on a light emitting portion made of a compound semiconductor.
A method of growing a crystal composed of GaAs or AlGaAs by a method of: maintaining a substrate temperature of 500 ° C. or higher and 550 ° C. or lower for 5 minutes or more while irradiating the surface of the GaInP layer with an As beam; Growing a crystal of GaAs or AlGaAs on the surface of the GaInP layer, whereby the above object is achieved.

According to the semiconductor crystal growth method of the present invention, the molecular beam epitaxy is formed on the GaInP layer provided on the light emitting portion made of a compound semiconductor.
Method, GaInP, AlGaInP or AlInP
And a step of holding the substrate temperature of 500 ° C. or higher and 550 ° C. or lower for 5 minutes or more while irradiating the surface of the GaInP layer with a P beam.
On the surface of the GaInP layer, GaInP, AlGaI
growing a crystal of nP or AlInP, whereby the above object is achieved.

The semiconductor crystal growth method of the present invention is a method of growing a crystal of GaAs or AlGaAs by a Molecular Beam Epitaxy method on a GaAs layer provided on a light emitting portion made of a compound semiconductor. The GaAs layer is etched away from the surface in the thickness direction by 100 angstroms or more to remove the Ga
A step of irradiating the surface of the As layer after etching with an As beam while maintaining the substrate temperature at 620 ° C. or higher and 700 ° C. or lower for 5 minutes or longer, and after the above step, the surface of the GaAs layer is made of GaAs or AlGaAs. Growing the crystal, whereby the above object is achieved.

The semiconductor crystal growth method of the present invention is a method of growing a crystal of GaInP, AlGaInP or AlInP on the GaAs layer provided on the light emitting portion made of a compound semiconductor by the molecular beam epitaxy method. , The GaAs layer is etched away from the surface in the thickness direction by 100 angstroms or more, and P is formed on the surface of the GaAs layer after the etching removal.
A step of holding the substrate temperature at 620 ° C. to 700 ° C. for 5 minutes or more while irradiating the beam, and
GaInP, AlGaInP or A on the surface of the layer
growing a crystal of lInP, whereby the above objective is achieved.

According to the semiconductor crystal growth method of the present invention, the molecular beam epitaxy is formed on the GaInP layer provided on the light emitting portion made of a compound semiconductor.
Is a method of growing a crystal of GaAs or AlGaAs by the method of: removing the GaInP layer by 100 angstroms or more from the surface in the thickness direction, and irradiating the surface of the GaInP layer after etching with an As beam on the substrate temperature. The method includes a step of holding at 500 ° C. or more and 550 ° C. or less for 5 minutes or more, and a step of growing a crystal of GaAs or AlGaAs on the surface of the GaInP layer after the above step, whereby the above object is achieved. It

According to the semiconductor crystal growth method of the present invention, the molecular beam epitaxy is formed on the GaInP layer provided on the light emitting portion made of a compound semiconductor.
Method, GaInP, AlGaInP or AlInP
And a substrate temperature of 500 ° C. or higher while irradiating a P beam on the surface of the GaInP layer after etching and removing the GaInP layer by etching by 100 angstroms or more from the surface in the thickness direction.
A step of holding at 0 ° C. or lower for 5 minutes or more, and after the above step, the G
GaInP, AlGaInP on the surface of the aInP layer
Or a step of growing a crystal made of AlInP, whereby the above object is achieved.

The operation of the present invention will be described below.

In the present invention, a GaAs layer or Ga
GaAs and AlGa are formed on the InP layer by the MBE method.
Before growing a crystal of As, GaInP, AlGaInP or AlInP, a GaAs layer or GaIn
Since the surface of the P layer is removed by etching for 100 angstroms or more, even if the surface is once exposed to the atmosphere and a metamorphic layer, an oxide film, contamination, etc. are generated, a good crystal growth surface can be obtained by removing them. can get. At this time, the GaAs layer or GaIn to be removed by etching
The reason why the thickness of the P layer from the surface is 100 angstroms or more is that it is difficult to completely remove the metamorphic layer, the oxide film, and the contamination when the thickness is less than 100 angstroms.

In the present invention, M is formed on the GaAs layer.
Before the crystal of GaAs or AlGaAs is grown by the BE method, the surface of the GaAs layer is kept at 620 ° C. or higher and 700 ° C. or lower for 5 minutes or more while being irradiated with an As beam. Even if a metamorphic layer, an oxide film, contamination, and the like are formed by exposure to, it is possible to obtain a good crystal growth surface by removing them. At this time, the substrate temperature is set to 620 ° C. or higher and 700 ° C. or lower because the GaAs oxide film is not completely desorbed below 620 ° C., and the GaAs re-evaporation occurs above 700 ° C. The process of keeping the substrate temperature constant while irradiating the surface of the GaAs layer with the As beam is performed by MBE.
Can be performed in a growth chamber in which a crystal made of GaAs or AlGaAs is grown by the method.

In the present invention, M is formed on the GaAs layer.
According to the BE method, GaInP, AlGaInP or Al
Before growing a crystal of InP, the surface of the GaAs layer is irradiated with a P beam and the substrate temperature is 620 ° C. or higher 700
Since the surface is kept at a temperature of 5 ° C. or lower for 5 minutes or more, even if a metamorphic layer, an oxide film, contamination, etc. are generated on the surface once exposed to the atmosphere, they can be removed to obtain a good crystal growth surface. At this time, the substrate temperature is 620 ° C. or higher and 700
The reason why the temperature is lower than or equal to C is for the same reason as described above. The step of irradiating the surface of the GaAs layer with the P beam and keeping the substrate temperature constant is performed by the MBE method using GaI.
It can be performed in a growth chamber in which a crystal made of nP, AlGaInP or AlInP is grown.

In the present invention, on the GaInP layer,
Before growing a crystal made of GaAs or AlGaAs by the MBE method, while irradiating the surface of the GaInP layer with an As beam, the substrate temperature is 500 ° C. or higher and 550 ° C. or lower.
Since the surface is kept for more than a minute, even if a metamorphic layer, an oxide film, contamination, etc. are generated on the surface once exposed to the atmosphere, they can be removed to obtain a good crystal growth surface. At this time, the substrate temperature is set to 500 ° C. or higher and 550 ° C. or lower because the GaInP oxide film is not completely desorbed when the temperature is lower than 500 ° C. and the re-evaporation of GaInP occurs when the temperature exceeds 550 ° C. In addition, A
The step of keeping the substrate temperature constant while irradiating the s-beam can be performed in a growth chamber in which a crystal made of GaAs or AlGaAs is grown by the MBE method.

In the present invention, on the GaInP layer,
According to the MBE method, GaInP, AlGaInP or A
Before growing the crystal of lInP, the surface of the GaInP layer is irradiated with a P beam and the substrate temperature is 500 ° C. or higher.
Since it is kept at 50 ° C or lower for 5 minutes or more, even if the surface is once exposed to the atmosphere and a metamorphic layer, an oxide film, contamination, etc. are generated, they are removed to obtain a good crystal growth surface. . At this time, the substrate temperature is 500 ° C or higher and 5
The reason why the temperature is set to 50 ° C. or lower is for the same reason as described above. The step of irradiating the surface of the GaInP layer with the P beam while keeping the substrate temperature constant is performed by the MBE method.
It can be performed in a growth chamber in which a crystal made of aInP, AlGaInP or AlInP is grown.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) In the first embodiment, Ga
A case where GaAs is crystal-grown on the As layer by the MBE method will be described.

FIG. 1C is a sectional view of the semiconductor laser device manufactured in the first embodiment.

This semiconductor laser device is a general ridge type AlGaInP semiconductor laser device. On the first conductivity type GaAs substrate 1, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP first clad layer 4, GaInP.
Active layer 5 and second conductivity type AlGaInP second cladding layer 6
And a GaInP etch stop layer 7 are provided. The second conductivity type AlGaInP third layer is formed on the central portion.
The cladding layer 8, the second conductivity type GaInP intermediate layer 9 and the second conductivity type GaAs cap layer 10 are provided in a ridge shape, and the first conductivity type G is formed so as to be embedded on both sides thereof.
An aAs current constriction layer 11 is provided. On top of that,
A second conductivity type GaAs contact layer 12 is provided. An electrode 14 is provided on the contact layer 12, and an electrode 15 is provided on the substrate side.

This semiconductor laser device can be manufactured as follows.

First, as shown in FIG. 1A, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP layer are formed on a first conductivity type GaAs substrate 1. 1 clad layer 4, GaInP active layer 5, second conductivity type AlGaInP second clad layer 6, G
aInP etch stop layer 7, second conductivity type AlGaIn
After the P third cladding layer 8, the second conductivity type GaInP intermediate layer 9 and the second conductivity type GaAs cap layer 10 are grown, the second conductivity type AlGaInP third cladding layer 8, the second conductivity type
The conductive type GaInP intermediate layer 9 and the second conductive type GaAs cap layer 10 are formed in a ridge shape, and the first conductive type GaAs current confinement layer 11 is grown so as to fill them on both sides thereof. In the steps up to this point, the surface of the second conductivity type GaAs cap layer 10 corresponding to the current path is exposed to the atmosphere.

Next, as shown in FIG. 1B, a portion of 100 angstroms or more is removed by etching from the surface of the second conductivity type GaAs cap layer 10 corresponding to the current path. At this time, similarly, the first conductivity type GaAs current constriction layer 11 is also removed from the surface in a portion of 100 angstroms or more. The portion removed by etching at this time is shown by 13 in FIG. This etching can be performed by, for example, a method such as perhydrogen sulfate-based wet etching. Further, after the etching, before the contact layer 12 is grown by the MBE method, it is preferable to store it in, for example, a nitrogen atmosphere so that the surface of the portion corresponding to the current path is not exposed to the atmosphere. This also applies to the following embodiments.

Then, as shown in FIG. 1C, MBE
The second conductivity type GaAs contact layer 12 is grown by the method to obtain a semiconductor laminated structure.

Then, an electrode 14 is formed on the contact layer 12.
And the electrode 15 is formed on the substrate side to obtain a semiconductor laser device.

Since the second conductivity type GaAs contact layer 12 is provided in this semiconductor laser device,
A distance can be provided from the active layer 9 which is the light emitting portion to the surface of the semiconductor laminated structure, and the distance between the light emitting portion and the mount mount of the stem can be lengthened. Therefore, it is possible to reduce mount distortion and mount leak that occur when the semiconductor laser device is mounted on the stem, and to improve device characteristics and yield.

Further, the second conductivity type GaAs contact layer 1
Before growing 2, the second conductivity type G corresponding to the current path
By removing the aAs cap layer 10 from the surface by 100 angstroms or more, GaA once exposed to the atmosphere
Even if a metamorphic layer, an oxide film, contamination or the like is generated on the surface of the s layer, these can be removed to obtain a good crystal growth surface. Therefore, the device resistance can be reduced, and a semiconductor laser device with a low operating voltage can be obtained with a high yield.

The semiconductor laser device obtained in the first embodiment was able to reduce the operating voltage to 2.2V to 2.5V, and it was also possible to improve the yield.

In the first embodiment, GaAs is crystal-grown as the second conductivity type contact layer 12, but
AlGaAs, GaInP, AlGaInP or Al
The same effect can be obtained also when InP is crystal-grown.

(Second Embodiment) In the second embodiment, Ga
A case where GaAs is crystal-grown on the InP layer by the MBE method will be described.

FIG. 2C is a sectional view of the semiconductor laser device manufactured in the second embodiment.

This semiconductor laser device is a general ridge type AlGaInP based semiconductor laser device. On the first conductivity type GaAs substrate 1, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP first clad layer 4, GaInP.
Active layer 5 and second conductivity type AlGaInP second cladding layer 6
And a GaInP etch stop layer 7 are provided. The second conductivity type AlGaInP third layer is formed on the central portion.
The clad layer 8 and the second conductivity type GaInP intermediate layer 9 are provided in a ridge shape, and the first conductivity type GaAs current constriction layer 11 is provided on both sides of the clad layer 8 so as to fill them. On top of that, a second conductivity type GaAs contact layer 12 is formed.
Is provided. An electrode 14 is provided on the contact layer 12.
However, the electrode 15 is provided on the substrate side.

This semiconductor laser device can be manufactured as follows.

First, as shown in FIG. 2A, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP layer are formed on a first conductivity type GaAs substrate 1. 1 clad layer 4, GaInP active layer 5, second conductivity type AlGaInP second clad layer 6, G
aInP etch stop layer 7, second conductivity type AlGaIn
After the P third cladding layer 8 and the second conductivity type GaInP intermediate layer 9 are grown, the second conductivity type AlGaInP third cladding layer 8 and the second conductivity type GaInP intermediate layer 9 are formed in a ridge shape, and on both sides thereof. First to embed them
The conductive type GaAs current confinement layer 11 is grown. In the steps up to here, the second conductivity type GaI corresponding to the current path
The surface of the nP intermediate layer 9 is exposed to the atmosphere.

Next, as shown in FIG. 2B, 1 from the surface of the second conductivity type GaInP intermediate layer 9 corresponding to the current path.
A portion of 00 Å or more is removed by etching.

At this time, the first conductivity type GaAs current confinement layer 11 is similarly removed from the surface in a portion of 100 angstroms or more. The portion removed by etching at this time is shown by 13 in FIG.

Then, as shown in FIG. 2C, MBE
The second conductivity type GaAs contact layer 12 is grown by the method to obtain a semiconductor laminated structure.

After that, the electrode 14 is formed on the contact layer 12.
And the electrode 15 is formed on the substrate side to obtain a semiconductor laser device.

In this semiconductor laser device, since the second conductivity type GaAs contact layer 12 is provided,
The distance from the active layer 9 which is the light emitting portion to the surface of the semiconductor laminated structure becomes longer, and the distance between the light emitting portion and the mount base of the stem can be lengthened. Therefore, it is possible to reduce mount distortion and mount leak that occur when the semiconductor laser device is mounted on the stem, and to improve device characteristics and yield.

The second conductivity type GaAs contact layer 1
Before growing 2, the second conductivity type G corresponding to the current path
By removing the aInP intermediate layer 9 from the surface by 100 angstroms or more, GaInP once exposed to the atmosphere
Even if a metamorphic layer, an oxide film, contamination, etc. occur on the layer surface, these can be removed to obtain a good crystal growth surface. Therefore, the element resistance can be lowered,
A semiconductor laser device having a low operating voltage can be obtained with high yield.

The semiconductor laser device obtained in the second embodiment can reduce the operating voltage to 2.2V to 2.5V and improve the yield.

Although GaAs is crystal-grown as the second conductivity type contact layer 12 in the second embodiment,
AlGaAs, GaInP, AlGaInP or Al
The same effect can be obtained also when InP is crystal-grown.

(Third Embodiment) In the third embodiment, Ga is
A case where GaAs is crystal-grown on the As layer by the MBE method will be described.

FIG. 3C is a sectional view of the semiconductor laser device manufactured in the third embodiment.

This semiconductor laser device is a general ridge type AlGaInP based semiconductor laser device. On the first conductivity type GaAs substrate 1, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP first clad layer 4, GaInP.
Active layer 5 and second conductivity type AlGaInP second cladding layer 6
And a GaInP etch stop layer 7 are provided. The second conductivity type AlGaInP third layer is formed on the central portion.
The cladding layer 8, the second conductivity type GaInP intermediate layer 9 and the second conductivity type GaAs cap layer 10 are provided in a ridge shape, and the first conductivity type G is formed so as to be embedded on both sides thereof.
An aAs current constriction layer 11 is provided. On top of that,
A second conductivity type GaAs contact layer 12 is provided. An electrode 14 is provided on the contact layer 12, and an electrode 15 is provided on the substrate side.

This semiconductor laser device can be manufactured as follows.

First, as shown in FIG. 3A, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP layer are formed on a first conductivity type GaAs substrate 1. 1 clad layer 4, GaInP active layer 5, second conductivity type AlGaInP second clad layer 6, G
aInP etch stop layer 7, second conductivity type AlGaIn
After the P third cladding layer 8, the second conductivity type GaInP intermediate layer 9 and the second conductivity type GaAs cap layer 10 are grown, the second conductivity type AlGaInP third cladding layer 8, the second conductivity type
The conductive type GaInP intermediate layer 9 and the second conductive type GaAs cap layer 10 are formed in a ridge shape, and the first conductive type GaAs current confinement layer 11 is grown so as to fill them on both sides thereof. In the steps up to this point, the surface of the second conductivity type GaAs cap layer 10 corresponding to the current path is exposed to the atmosphere.

Next, as shown in FIG. 3B, the substrate temperature is maintained at 620 ° C. or higher and 700 ° C. or lower for 5 minutes or longer while irradiating the As substrate on the wafer substrate in the MBE growth chamber. By carrying out the above treatment in the MBE growth chamber as described above, it is possible to prevent the surface of the portion corresponding to the current path from being exposed to the atmosphere before growing the contact layer 12 by the MBE method. Moreover, since the growth material of the contact layer 12 can be used as the As beam to be irradiated, the process is facilitated. This also applies to the following embodiments.

Then, as shown in FIG. 3C, MBE
The second conductivity type GaAs contact layer 12 is grown by the method to obtain a semiconductor laminated structure.

After that, the electrode 14 is formed on the contact layer 12.
And the electrode 15 is formed on the substrate side to obtain a semiconductor laser device.

In this semiconductor laser device, since the second conductivity type GaAs contact layer 12 is provided,
The distance from the active layer 9 which is the light emitting portion to the surface of the semiconductor laminated structure becomes longer, and the distance between the light emitting portion and the mount base of the stem can be lengthened. Therefore, it is possible to reduce mount distortion and mount leak that occur when the semiconductor laser device is mounted on the stem, and to improve device characteristics and yield.

Further, the second conductivity type GaAs contact layer 1
Before growing 2, the second conductivity type G corresponding to the current path
By maintaining the substrate temperature at 620 ° C. to 700 ° C. for 5 minutes or more while irradiating the surface of the aAs cap layer 10 with an As beam, a metamorphic layer, an oxide film, contamination, etc. on the surface of the GaAs layer once exposed to the atmosphere. Even if such a phenomenon occurs, these can be removed to obtain a good crystal growth surface. Therefore, the device resistance can be reduced, and a semiconductor laser device with a low operating voltage can be obtained with a high yield.

The semiconductor laser device obtained in the third embodiment was able to reduce the operating voltage to 2.2V to 2.5V and improve the yield.

In the third embodiment, GaAs was crystal-grown as the second conductivity type contact layer 12, but
The same effect can be obtained in the case of crystal growth of AlGaAs.

Further, GaInP, AlGaInP, or AlInP may be crystal-grown as the second conductivity type contact layer 12. In that case, the surface of the second conductivity type GaAs cap layer 10 is irradiated with the As beam in the MBE growth chamber. Substrate temperature 620 while irradiating with P beam instead
The same effect can be obtained by holding the temperature at not lower than 700 ° C and not higher than 700 ° C for 5 minutes or longer.

(Fourth Embodiment) In the fourth embodiment, Ga
A case where GaAs is crystal-grown on the InP layer by the MBE method will be described.

FIG. 4C shows a sectional view of the semiconductor laser device manufactured in the fourth embodiment.

This semiconductor laser device is a general ridge type AlGaInP based semiconductor laser device. On the first conductivity type GaAs substrate 1, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP first clad layer 4, GaInP.
Active layer 5 and second conductivity type AlGaInP second cladding layer 6
And a GaInP etch stop layer 7 are provided. The second conductivity type AlGaInP third layer is formed on the central portion.
The clad layer 8 and the second conductivity type GaInP intermediate layer 9 are provided in a ridge shape, and the first conductivity type GaAs current constriction layer 11 is provided on both sides of the clad layer 8 so as to fill them. On top of that, a second conductivity type GaAs contact layer 12 is formed.
Is provided. An electrode 14 is provided on the contact layer 12.
However, the electrode 15 is provided on the substrate side.

This semiconductor laser device can be manufactured as follows.

First, as shown in FIG. 4A, on the first conductivity type GaAs substrate 1, the first conductivity type GaAs buffer layer 2, the first conductivity type GaInP buffer layer 3, the first conductivity type AlGaInP layer are formed. 1 clad layer 4, GaInP active layer 5, second conductivity type AlGaInP second clad layer 6, G
aInP etch stop layer 7, second conductivity type AlGaIn
After the P third cladding layer 8 and the second conductivity type GaInP intermediate layer 9 are grown, the second conductivity type AlGaInP third cladding layer 8 and the second conductivity type GaInP intermediate layer 9 are formed in a ridge shape, and on both sides thereof. First to embed them
The conductive type GaAs current confinement layer 11 is grown. In the steps up to here, the second conductivity type GaI corresponding to the current path
The surface of the nP intermediate layer 9 is exposed to the atmosphere.

Next, as shown in FIG. 4B, the substrate temperature is kept at 500 ° C. or more and 550 ° C. or less for 5 minutes or more while irradiating the As beam on the wafer substrate in the MBE growth chamber.

Then, as shown in FIG. 4C, MBE
The second conductivity type GaAs contact layer 12 is grown by the method to obtain a semiconductor laminated structure.

After that, the electrode 14 is formed on the contact layer 12.
And the electrode 15 is formed on the substrate side to obtain a semiconductor laser device.

In this semiconductor laser device, by providing the GaAs contact layer 12 of the second conductivity type, the distance from the active layer 9 which is the light emitting portion to the surface of the semiconductor laminated structure becomes longer, and the light emitting portion and the mount base of the stem are provided. The distance between can be longer. Therefore, it is possible to reduce mount distortion and mount leak that occur when the semiconductor laser device is mounted on the stem, and to improve device characteristics and yield.

Further, the second conductivity type GaAs contact layer 1
Before growing 2, the second conductivity type G corresponding to the current path
By irradiating the surface of the aInP intermediate layer 9 with an As beam and holding the substrate temperature at 500 ° C. or higher and 550 ° C. or lower for 5 minutes or longer, the surface of the GaInP layer once exposed to the atmosphere is subject to a metamorphic layer, oxide film, contamination, Even if
These can be removed to obtain a good crystal growth surface. Therefore, the device resistance can be reduced, and a semiconductor laser device with a low operating voltage can be obtained with a high yield.

The semiconductor laser device obtained in the fourth embodiment was able to reduce the operating voltage to 2.2V to 2.5V and improve the yield.

Although GaAs is crystal-grown as the second conductivity type contact layer 12 in the fourth embodiment,
The same effect can be obtained in the case of crystal growth of AlGaAs.

Further, GaInP, AlGaInP, or AlInP may be crystal-grown as the second-conductivity-type contact layer 12. In that case, an As beam is applied to the surface of the second-conductivity-type GaInP intermediate layer 9 in the MBE growth chamber. Alternatively, the same effect can be obtained by holding the substrate temperature at 620 ° C. or higher and 700 ° C. or lower for 5 minutes or more while irradiating the P beam.

(Fifth Embodiment) In the fifth embodiment, Ga is
A case where GaAs is crystal-grown on the As layer by the MBE method will be described.

FIG. 5C shows a sectional view of the semiconductor laser device manufactured in the fifth embodiment.

This semiconductor laser device is a general ridge type AlGaInP based semiconductor laser device. On the first conductivity type GaAs substrate 1, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP first clad layer 4, GaInP.
Active layer 5 and second conductivity type AlGaInP second cladding layer 6
And a GaInP etch stop layer 7 are provided. The second conductivity type AlGaInP third layer is formed on the central portion.
The cladding layer 8, the second conductivity type GaInP intermediate layer 9 and the second conductivity type GaAs cap layer 10 are provided in a ridge shape, and the first conductivity type G is formed so as to be embedded on both sides thereof.
An aAs current constriction layer 11 is provided. On top of that,
A second conductivity type GaAs contact layer 12 is provided. An electrode 14 is provided on the contact layer 12, and an electrode 15 is provided on the substrate side.

This semiconductor laser device can be manufactured as follows.

First, as shown in FIG. 5A, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP layer are formed on a first conductivity type GaAs substrate 1. 1 clad layer 4, GaInP active layer 5, second conductivity type AlGaInP second clad layer 6, G
aInP etch stop layer 7, second conductivity type AlGaIn
After the P third cladding layer 8, the second conductivity type GaInP intermediate layer 9 and the second conductivity type GaAs cap layer 10 are grown, the second conductivity type AlGaInP third cladding layer 8, the second conductivity type
The conductive type GaInP intermediate layer 9 and the second conductive type GaAs cap layer 10 are formed in a ridge shape, and the first conductive type GaAs current confinement layer 11 is grown so as to fill them on both sides thereof. In the steps up to this point, the surface of the second conductivity type GaAs cap layer 10 corresponding to the current path is exposed to the atmosphere.

Next, as shown in FIG. 5B, a portion of 100 angstroms or more is removed by etching from the surface of the second conductivity type GaAs cap layer 10 corresponding to the current path. At this time, similarly, the first conductivity type GaAs current constriction layer 11 is also removed from the surface in a portion of 100 angstroms or more. The portion removed by etching at this time is shown by 13 in FIG.

Next, as shown in FIG. 5C, the substrate temperature is maintained at 620 ° C. or higher and 700 ° C. or lower for 5 minutes or more while irradiating the As beam on the wafer substrate in the MBE growth chamber.

Then, as shown in FIG. 5C, MBE
The second conductivity type GaAs contact layer 12 is grown by the method to obtain a semiconductor laminated structure.

After that, the electrode 14 is formed on the contact layer 12.
And the electrode 15 is formed on the substrate side to obtain a semiconductor laser device.

In this semiconductor laser device, by providing the GaAs contact layer 12 of the second conductivity type, the distance from the active layer 9 which is the light emitting portion to the surface of the semiconductor laminated structure becomes longer, and the light emitting portion and the mount mount of the stem are provided. The distance between can be longer. Therefore, it is possible to reduce mount distortion and mount leak that occur when the semiconductor laser device is mounted on the stem, and to improve device characteristics and yield.

Further, the second conductivity type GaAs contact layer 1
Before growing 2, the second conductivity type G corresponding to the current path
The aAs cap layer 10 is removed from the surface by 100 Å or more, and the surface of the second conductivity type GaAs cap layer 10 after the removal is irradiated with an As beam and the substrate temperature is set to 620.
By keeping the temperature above ℃ to 700 ℃ for 5 minutes or more, even if a metamorphic layer, an oxide film, and contamination occur on the surface of the GaAs layer once exposed to the atmosphere, these are removed and a good crystal growth surface is obtained. Obtainable. Therefore, the device resistance can be reduced, and a semiconductor laser device with a low operating voltage can be obtained with a high yield.

The semiconductor laser device obtained in the fifth embodiment was able to reduce the operating voltage to 2.2 V to 2.5 V, and the yield could be improved.

Although GaAs is crystal-grown as the second conductivity type contact layer 12 in the fifth embodiment,
The same effect can be obtained in the case of crystal growth of AlGaAs.

Further, GaInP, AlGaInP or AlInP may be crystal-grown as the second conductivity type contact layer 12, and in this case, the second conductivity type GaAs cap layer 10 corresponding to the current path is 100 angstroms or more from the surface. After removing, in the MBE growth chamber, As is formed on the surface of the second conductivity type GaAs cap layer 10 after the removal.
Substrate temperature 62 while irradiating P beam instead of beam
By holding at 0 ℃ or more and 700 ℃ or less for 5 minutes or more,
The same effect can be obtained.

(Sixth Embodiment) In this sixth embodiment, Ga is
A case where GaAs is crystal-grown on the InP layer by the MBE method will be described.

FIG. 6C shows a sectional view of the semiconductor laser device manufactured in the sixth embodiment.

This semiconductor laser device is a general ridge type AlGaInP based semiconductor laser device. On the first conductivity type GaAs substrate 1, a first conductivity type GaAs buffer layer 2, a first conductivity type GaInP buffer layer 3, a first conductivity type AlGaInP first clad layer 4, GaInP.
Active layer 5 and second conductivity type AlGaInP second cladding layer 6
And a GaInP etch stop layer 7 are provided. The second conductivity type AlGaInP third layer is formed on the central portion.
The clad layer 8 and the second conductivity type GaInP intermediate layer 9 are provided in a ridge shape, and the first conductivity type GaAs current constriction layer 11 is provided on both sides of the clad layer 8 so as to fill them. On top of that, a second conductivity type GaAs contact layer 12 is formed.
Is provided. An electrode 14 is provided on the contact layer 12.
However, the electrode 15 is provided on the substrate side.

This semiconductor laser device can be manufactured as follows.

First, as shown in FIG. 6A, on the first conductivity type GaAs substrate 1, the first conductivity type GaAs buffer layer 2, the first conductivity type GaInP buffer layer 3, the first conductivity type AlGaInP layer are formed. 1 clad layer 4, GaInP active layer 5, second conductivity type AlGaInP second clad layer 6, G
aInP etch stop layer 7, second conductivity type AlGaIn
After the P third cladding layer 8 and the second conductivity type GaInP intermediate layer 9 are grown, the second conductivity type AlGaInP third cladding layer 8 and the second conductivity type GaInP intermediate layer 9 are formed in a ridge shape, and on both sides thereof. First to embed them
The conductive type GaAs current confinement layer 11 is grown. In the steps up to here, the second conductivity type GaI corresponding to the current path
The surface of the nP intermediate layer 9 is exposed to the atmosphere.

Next, as shown in FIG. 6B, 1 from the surface of the second conductivity type GaInP intermediate layer 9 corresponding to the current path.
A portion of 00 Å or more is removed by etching. At this time, similarly, the first conductivity type GaAs current constriction layer 11 is also removed from the surface in a portion of 100 angstroms or more. The portion removed by etching at this time is shown in FIG.
It is shown at 13 in (b).

Next, as shown in FIG. 6C, the substrate temperature is kept at 500 ° C. or higher and 550 ° C. or lower for 5 minutes or more while irradiating the As beam on the wafer substrate in the MBE growth chamber.

Then, as shown in FIG. 6C, MBE
The second conductivity type GaAs contact layer 12 is grown by the method to obtain a semiconductor laminated structure.

After that, the electrode 14 is formed on the contact layer 12.
And the electrode 15 is formed on the substrate side to obtain a semiconductor laser device.

In this semiconductor laser device, by providing the GaAs contact layer 12 of the second conductivity type, the distance from the active layer 9 which is the light emitting portion to the surface of the semiconductor laminated structure becomes longer, and the light emitting portion and the mount mount of the stem are provided. The distance between can be longer. Therefore, it is possible to reduce mount distortion and mount leak that occur when the semiconductor laser device is mounted on the stem, and to improve device characteristics and yield.

Also, the second conductivity type GaAs contact layer 1
Before growing 2, the second conductivity type G corresponding to the current path
The aInP intermediate layer 9 is removed from the surface by 100 Å or more, and the surface of the removed second conductivity type GaInP intermediate layer 9 is irradiated with an As beam and the substrate temperature is 500 ° C. or higher.
By maintaining the temperature at 50 ° C or lower for 5 minutes or more, even if a metamorphic layer, an oxide film, and contamination occur on the surface of the GaInP layer once exposed to the atmosphere, these can be removed to obtain a good crystal growth surface. You can Therefore, the device resistance can be reduced, and a semiconductor laser device with a low operating voltage can be obtained with a high yield.

The semiconductor laser device obtained in the sixth embodiment was able to reduce the operating voltage to 2.2V to 2.5V, and also to improve the yield.

Although GaAs was crystal-grown as the second conductivity type contact layer 12 in the sixth embodiment,
The same effect can be obtained in the case of crystal growth of AlGaAs.

Further, GaInP, AlGaInP or AlInP may be crystal-grown as the second conductivity type contact layer 12, and in this case, the second conductivity type GaInP intermediate layer 9 corresponding to the current path is 100 angstroms or more from the surface. By removing and removing the surface of the second conductivity type GaInP intermediate layer 9 after removal in the MBE growth chamber while irradiating a P beam instead of an As beam, the substrate temperature is maintained at 620 ° C. or higher and 700 ° C. or lower for 5 minutes or more. The same effect can be obtained.

In the first to sixth embodiments, the example in which the present invention is applied to the manufacture of a general ridge type AlGaInP based semiconductor laser device has been described. However, the GaAs layer or the GaInP layer provided on the light emitting portion is described. GaAs, AlGaAs, GaInP, AlGa by the MBE method
The present invention can be applied to any structure as long as a crystal made of InP or AlInP is grown. For example, SAS as shown in FIG.
(Self-Aligned Structure) structure and VSIS (V-Channel) as shown in FIG.
d Substrate Inner Strip (CSP) structure, as shown in FIG.
an inverted planar structure, a BH (Buried Hetero structure) as shown in FIG.
structure, TJ (Terra) as shown in FIG.
GaAs in the ced Substrate structure
On the layer or the GaInP layer by the MBE method,
AlGaAs, GaInP, AlGaInP or Al
The present invention is also applicable to the case of growing a contact layer made of InP. In these figures, 21 is an n-type substrate, 22 is an n-type cladding layer, 23 is an active layer, 24 is a p-type cladding layer, 25 is an n-type current constriction layer,
26 is an n-type cap layer, 27 is a Zn diffusion layer, 31 is a p-type substrate, 32 is an n-type cap layer, 33 is a p-type current confinement layer,
Reference numeral 34 indicates an n ⁻ type current constriction layer. Further, although not shown in the figure, an LED (Light Emitting Dio)
de) structure on the GaAs layer or GaInP layer by the MBE method, GaAs, AlGaAs, GaIn
The present invention is also applicable to the case of growing a crystal made of P, AlGaInP or AlInP.

[0112]

As described in detail above, according to the present invention,
G on the GaAs layer or GaInP layer by MBE method
Before growing a crystal made of aAs, AlGaAs, GaInP, AlGaInP or AlInP, even if the crystal growth surface is once exposed to the atmosphere and a metamorphic layer, an oxide film and contamination are generated on the surface, remove them. A good crystal growth surface can be obtained.

Therefore, by using the semiconductor crystal growth method of the present invention in the manufacture of a semiconductor light emitting device, a current is generated before the contact layer is grown to provide a distance between the light emitting portion and the mount base of the stem. The crystal growth surface of the portion corresponding to the path can be made good. Therefore, it is possible to obtain a semiconductor light emitting device having a good yield as well as a low device resistance and a low operating voltage.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing process of a semiconductor laser device according to a first embodiment.

FIG. 2 is a cross-sectional view showing the manufacturing process of the semiconductor laser device according to the second embodiment.

FIG. 3 is a cross-sectional view showing the manufacturing process of the semiconductor laser device according to the third embodiment.

FIG. 4 is a cross-sectional view showing the manufacturing process of the semiconductor laser device according to the fourth embodiment.

FIG. 5 is a cross-sectional view showing the manufacturing process of the semiconductor laser device according to the fifth embodiment.

FIG. 6 is a cross-sectional view showing the manufacturing process of the semiconductor laser device according to the sixth embodiment.

FIG. 7 is a cross-sectional view showing a SAS structure.

FIG. 8 is a sectional view showing a VSIS structure.

FIG. 9 is a cross-sectional view showing a CSP structure.

FIG. 10 is a cross-sectional view showing a BH structure.

FIG. 11 is a cross-sectional view showing a TJ structure.

FIG. 12 is a cross-sectional view showing a manufacturing process of a conventional semiconductor laser device.

FIG. 13 is a cross-sectional view showing a manufacturing process of a conventional semiconductor laser device.

[Explanation of symbols]

1 First conductivity type GaAs substrate 2 First conductivity type GaAs buffer layer 3 First conductivity type GaInP buffer layer 4 First conductivity type AlGaInP first cladding layer 5 GaInP active layer 6 Second conductivity type AlGaInP second cladding layer 7 GaInP etch stop layer 8 Second conductivity type AlGaInP third cladding layer 9 Second conductivity type GaInP intermediate layer 10 Second conductivity type GaAs cap layer 11 First conductivity type GaAs current confinement layer 12 Second conductivity type GaAs contact layer 13 Parts to be removed by etching 14, 15 electrodes

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21 / 203,21 / 363 C30B 23/08 C30B 29/40-29/44

Claims (2)

(57) [Claims] 1. A molecular B is provided on a GaInP layer provided on a light emitting portion made of a compound semiconductor.
GaInP, AlGa by the electron epitaxy method
A method of growing a crystal composed of InP or AlInP, which comprises a step of irradiating the surface of the GaInP layer with a P beam and holding the substrate temperature at 500 ° C. or higher and 550 ° C. or lower for 5 minutes or longer, and after the step, the GaInP layer On the surface of GaIn
Growing a crystal of P, AlGaInP or AlInP. 2. A molecular B is provided on the GaInP layer provided on the light emitting portion made of a compound semiconductor.
GaInP, AlGa by the electron epitaxy method
A method for growing a crystal of InP or AlInP, which comprises removing the GaInP layer by 100 angstroms or more in the thickness direction from the surface, and irradiating the surface of the GaInP layer after etching with a P beam at a substrate temperature of 5
A step of holding at a temperature of 00 ° C. or higher and 550 ° C. or lower for 5 minutes or more, and after the above step, GaInP is formed on the surface of the GaInP layer.
Growing a crystal of P, AlGaInP or AlInP.