JP2003174235A - Method and apparatus for manufacturing semiconductor light emitting element, optical transmission module, optical transmission and receiving module and optical communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remarkably improve light emitting characteristics in a semiconductor light emitting element having a semiconductor layer containing Al and provided between a substrate and an active layer containing nitrogen. <P>SOLUTION: The method for manufacturing the semiconductor light emitting element comprises the steps of providing the semiconductor layer containing Al between the substrate and the active layer containing nitrogen, and differentiating a suscepter for holding the substrate when the semiconductor layer containing Al is grown from a suscepter for holding the substrate when the active layer containing nitrogen is grown when the active layer containing nitrogen and the semiconductor layer containing Al are grown by using the nitrogen compound raw material and an organic metal Al material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device manufacturing method, a semiconductor light emitting device manufacturing apparatus, an optical transmission module, an optical transmission / reception module, and an optical communication system.

[0002]

2. Description of the Related Art As represented by the Internet, the amount of information handled by optical communication has increased dramatically due to the explosive spread of networks in recent years, and it is considered that it will increase thereafter. Therefore, not only trunk lines, but also metro networks, transmission lines close to users such as subscribers such as ordinary homes and offices, and LAN (Local Area Network), and optical fibers are also introduced into the wiring between devices and within devices. Is being done. For this reason, optical large-capacity information transmission technology has become extremely important.

In order to promote the spread of optical fibers and optical wiring to networks closer to end users, a light source that is cheaper, smaller, and has good compatibility with optical fibers is required. As such a light source, a VCSEL (Vertical Cavity Surface Emittin) having a 1.3 μm band and a 1.55 μm band surface-emitting type semiconductor laser device with a small transmission loss of silica fiber and good compatibility
g Laser: Vertical cavity surface emitting semiconductor laser device) is extremely promising. The surface-emitting type semiconductor laser device is lower in price, lower in power consumption, smaller in size than the edge-emitting type laser,
Suitable for two-dimensional integration, 1Gbi is already a high-speed LAN in the 0.85 μm band that can be actually formed on a GaAs substrate.
It is put to practical use in t / s Ethernet (registered trademark) and the like.

At present, the material system on the InP substrate is generally used in the 1.3 μm band, and is used in the edge emitting semiconductor laser. However, in these conventional long wavelength band semiconductor lasers, when the ambient temperature rises from room temperature to 80 ° C.,
Since it has a big drawback that the operating current is tripled due to the temperature characteristic, it is necessary to consider the cooling means and the like, which is a factor of increasing the cost. Further, in the surface-emitting type semiconductor laser device, since there is no material suitable for the reflecting mirror, it is difficult to achieve high performance, and the characteristics at a practical level are not obtained at present. Also GaAs / A
Although it has been proposed to use it as an active layer on an InP substrate by laminating an lGaAs reflecting mirror, there are many problems in mass production because of high cost.

Therefore, recently, 1.3 μm on a GaAs substrate
Attention has been paid to material systems capable of forming a band. Among these material systems, GaInNAs is attracting attention as a material that can extremely reduce the temperature dependence of laser characteristics.
That is, GaInNAs is considered to be promising as a light source for an optical network of a medium scale or less because it can have a simple cooling mechanism, a small size, and a low cost due to its small temperature dependence. GaInNAs has a narrow band gap by containing N in its crystal.
A technique for growing an active layer containing a high quality is very important.

Conventionally, Japanese Patent Laid-Open No. 10-126004 discloses that
When a GaInNAs active layer and a layer containing Al are grown in direct contact with each other, nitrogen is segregated at the interface to deteriorate the surface morphology and significantly reduce the emission intensity. A structure that does not contain Al has been proposed.

Further, in Japanese Patent Laid-Open No. 2000-4068, G
By providing an intermediate layer not containing Al and N as constituent elements between the aInNP active layer and the AlGaInP clad layer, the crystallinity and the luminous efficiency are improved.

However, it has been reported that the luminous efficiency of the GaInNAs active layer formed on the semiconductor layer containing Al is lowered even when the intermediate layer is provided. That is, the document “Electo
ron. Lett., 2000, 36 (21), pp1776-1777 ”, reported that photoluminescence intensity was significantly deteriorated when a GaInNAs quantum well layer was continuously grown on an AlGaAs cladding layer in the same MOCVD growth chamber. Has been done. In the above document, in order to improve the photoluminescence intensity, an AlGaAs cladding layer and GaInN are used.
The As active layer is grown in different MOCVD growth chambers.

[0009]

FIG. 1 shows a GaInNAs / G layer composed of a GaInNAs quantum well layer and a GaAs barrier layer produced by an MOCVD apparatus by the inventor of the present application.
It is a figure which shows the room temperature photoluminescence spectrum of aAs2 double quantum well structure. In addition, in FIG.
Shows a sample in which a double quantum well structure is formed on an AlGaAs clad layer with a GaAs intermediate layer sandwiched therebetween.
Reference symbol B indicates a sample in which a double quantum well structure is continuously formed on a GaInP clad layer with a GaAs intermediate layer sandwiched therebetween.

As shown in FIG. 1, the photoluminescence intensity of sample A is lower than half that of sample B. From this, using one MOCVD apparatus,
When an active layer containing nitrogen such as GaInNAs is continuously formed on a semiconductor layer containing Al as a constituent element such as 1GaAs, there arises a problem that the emission intensity of the active layer deteriorates as in the conventional example. I understand. For this reason,
There is a problem that the threshold current density of a GaInNAs-based laser formed on the AlGaAs clad layer is twice or more higher than that when formed on the GaInP clad layer.

The present invention relates to a method for manufacturing a semiconductor light emitting device, in which a semiconductor layer containing Al is provided between a substrate and an active layer containing nitrogen, in which the light emitting characteristics can be remarkably improved. An object of the present invention is to provide a semiconductor light emitting device manufacturing apparatus, an optical transmission module, an optical transmission / reception module, and an optical communication system.

[0012]

In order to achieve the above object, the invention according to claim 1 provides a semiconductor layer containing Al between a substrate and an active layer containing nitrogen, and the active layer containing nitrogen. In the method for manufacturing a semiconductor light emitting device, wherein the semiconductor layer containing Al and the semiconductor layer containing Al are grown using a nitrogen compound raw material and an organometallic Al raw material, respectively, and a susceptor for holding a substrate when growing the semiconductor layer containing Al; It is characterized in that the susceptor that holds the substrate when growing the active layer containing nitrogen is different.

According to a second aspect of the present invention, a semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen and the semiconductor layer containing Al are each made of a nitrogen compound. In an apparatus for manufacturing a semiconductor light emitting device that grows using a raw material and an organometallic Al raw material, a susceptor that holds a substrate when growing the Al-containing semiconductor layer and a substrate when growing the nitrogen-containing active layer are used. It is characterized in that the susceptor to be held is different.

According to a third aspect of the invention, in the semiconductor light emitting device manufacturing apparatus according to the second aspect, the susceptor for growing the active layer containing nitrogen is grown during the growth of the semiconductor layer containing Al. After the growth of the semiconductor layer containing Al was completed, the susceptor for growing the active layer containing nitrogen and the semiconductor layer containing Al were grown in a separate room after the growth of the semiconductor layer containing Al was completed. It is characterized by having a structure that can be replaced with a susceptor.

According to a fourth aspect of the present invention, a semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen and the semiconductor layer containing Al are each made of a nitrogen compound. In a method of manufacturing a semiconductor light emitting device using a raw material and an organic metal Al raw material, a susceptor for holding a substrate has a removable cover for covering a portion other than a portion for directly holding the substrate. It is characterized in that a cover is attached when growing the semiconductor layer containing nitrogen, and a cover is removed when growing the active layer containing nitrogen.

According to a fifth aspect of the present invention, a semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen and the semiconductor layer containing Al are each provided with a nitrogen compound. In a semiconductor light emitting device manufacturing apparatus in which a raw material and an organometallic Al raw material are used for growth, a susceptor for holding a substrate has a detachable cover for covering a portion other than a portion for directly holding the substrate. It is characterized in that it has a mechanism of attaching a cover when growing the semiconductor layer containing nitrogen and removing the cover when growing the active layer containing nitrogen.

According to a sixth aspect of the invention, in the apparatus for manufacturing a semiconductor light emitting element according to the fifth aspect, the removable cover has a mechanism that is removable with the susceptor loaded in the reaction chamber. It is characterized by

The invention according to claim 7 is the method for manufacturing a semiconductor light emitting device according to claim 1 or 4, or the method according to claim 2 or 3 or claim 5 or claim 6. A surface-emitting type semiconductor laser device manufactured by a semiconductor light-emitting device manufacturing apparatus.

An eighth aspect of the present invention is an optical transmitter module using the surface emitting semiconductor laser element according to the seventh aspect.

According to a ninth aspect of the present invention, there is provided an optical transmitter-receiver module comprising the surface-emitting type semiconductor laser device according to the seventh aspect.

Further, the invention according to claim 10 is the invention according to claim 7.
It is an optical communication system characterized by using the surface emitting semiconductor laser device described.

[0022]

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

FIG. 2 is a diagram showing an example of a semiconductor light emitting device in which a semiconductor layer containing Al is provided between a substrate and a semiconductor layer containing nitrogen. In the semiconductor light emitting device of FIG. 2, the first semiconductor layer 202 containing Al, the intermediate layer 203, the active layer 204 containing nitrogen, and the intermediate layer 20 are provided on the substrate 201.
3 and the second semiconductor layer 205 are sequentially stacked.

Here, on the substrate 201, for example, GaA
A compound semiconductor substrate of s, InP, GaP or the like is used.

In the first semiconductor layer 202 containing Al as a constituent element, AlAs, AlP, AlGaAs,
AlInP, AlGaInP, AlInAs, AlIn
Materials such as AsP and AlGaInAsP can be used. Note that the first semiconductor layer 202 is not limited to a single layer and may be a stack of a plurality of semiconductor layers containing Al as a constituent element.

The intermediate layer 203 has A as a constituent element.
l is not included, for example, GaAs, GaP, InP,
It is made of materials such as GaInP, GaInAs, and GaInAsP.

Further, the active layer 204 containing nitrogen is formed, for example, in GaNAs, GaPN, GaInNAs, GaInN.
Materials such as P, GaNAsSb, and GaInNAsSb are used, and the active layer 204 containing nitrogen is crystal-grown without intentionally introducing the Al raw material. Further, the active layer 204 is not limited to a single layer, but can be configured to have a multiple quantum well structure in which a semiconductor containing nitrogen is used as a well layer and an intermediate layer material is used as a barrier layer.

The energy band gaps of the respective layers of the semiconductor light emitting device of FIG. 2 are determined by the active layer 204, the intermediate layer 203 and the first layer.
The semiconductor layer 202 and the second semiconductor layer 205 are larger in this order. Note that the second semiconductor layer 205 has the first
In general, the same material as that of the semiconductor layer 202 of
It is also possible to use a material that does not contain Al.

The semiconductor light emitting device shown in FIG. 2 can be subjected to crystal growth using an epitaxial growth apparatus using an organic metal Al raw material and a nitrogen compound raw material. Here, as the organic metal Al raw material, for example, TMA or TEA can be used. Further, as the nitrogen compound raw material, DMH
Organic nitrogen raw materials such as y and MMHy and NH ₃ can be used. Further, as the crystal growth method, MOCVD method or CBE method can be used.

FIG. 3 shows a first semiconductor layer 202 and a second semiconductor layer 205 as an example of the semiconductor light emitting device of FIG.
1 GaAs, the intermediate layer 203 is GaAs, and the nitrogen-containing active layer 204 is a GaInNAs / GaAs double quantum well structure. When a semiconductor light emitting device is formed using one epitaxial growth apparatus (MOCVD), nitrogen ( It is a figure which shows the depth direction distribution of N) density | concentration and oxygen (O) density | concentration. In addition, this measurement was performed by SIMS. The following table (Table 1) shows the measurement conditions.

[0031]

[Table 1]

In FIG. 3, GaInNAs / GaAs
Two nitrogen concentration peaks are seen in the active layer 204 corresponding to the double quantum well structure. Then, in the active layer 204, a peak of oxygen concentration is detected. However, A
The oxygen concentration in the intermediate layer 203 that does not include l is about one digit lower than the oxygen concentration in the active layer 204.

On the other hand, the first semiconductor layer 202 and the second semiconductor layer 205 are made of GaInP, and the intermediate layer 203 is made of GaAs.
And the active layer 204 containing nitrogen is replaced by GaInNAs / Ga
For the semiconductor light emitting device configured as an As2 quantum well structure, when the depth distribution of oxygen concentration is measured,
The oxygen concentration in the active layer 204 was at the background level.

That is, the nitrogen compound raw material and the organometallic Al
Using the raw materials, one epitaxial growth system,
When the semiconductor light emitting device in which the semiconductor layer (202) containing Al is provided between the substrate (201) and the active layer (204) containing nitrogen is continuously crystal-grown, an active layer (20) containing nitrogen is obtained.
It was clarified by the experiment of the inventor of the present application that oxygen is taken into 4). Oxygen taken in the active layer (204) forms a non-radiative recombination level, so that the active layer (2
The luminous efficiency of 04) is reduced. This active layer (2
Oxygen taken into the semiconductor layer (2) contains Al between the substrate (201) and the active layer (204) containing nitrogen.
02) is newly found to be the cause of lowering the luminous efficiency of the semiconductor light emitting device.

The mechanism of oxygen uptake is considered as follows. That is, when a semiconductor layer containing Al as a constituent element is grown, an Al raw material in the growth chamber, or
Al reactant, Al compound, or Al remains. After that, when a nitrogen compound raw material is supplied to the growth chamber during crystal growth of a semiconductor layer containing nitrogen, the nitrogen compound raw material or impurities such as moisture contained in the nitrogen compound raw material, and a chemically active Al raw material, or , Al reactant, Al compound, or Al chemically bond with each other, and Al is incorporated into the active layer. Further, Al reacts with water contained in the nitrogen compound raw material, oxygen impurities are also taken into the active layer at the same time, and the luminous efficiency of the active layer is reduced.

As described above, the residue of the Al-containing substance in the growth chamber is combined with the nitrogen compound raw material or impurities such as water contained in the nitrogen compound raw material and the residual Al-containing substance to form the active layer. It was found that the inclusion is a factor in the manufacturing process that lowers the luminous efficiency in the semiconductor light emitting device in which the semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen.

The present invention intends to solve such a factor in the manufacturing process and form an active layer containing nitrogen with high luminous efficiency on a semiconductor layer containing Al.

First Embodiment As described above, when a semiconductor light emitting device in which a semiconductor layer containing Al is provided between a substrate and an active layer containing nitrogen, a substance containing Al remains in the growth. Is a cause of the decrease in luminous efficiency, and preventing it is effective for improving luminous efficiency. For example, in the MOCVD method or the like, the gas flow of the raw material is blown onto the substrate, so that the susceptor near the substrate, particularly the susceptor adjacent to the substrate, is easily exposed to the raw material gas and the substance generated by the reaction on the substrate, resulting in Al
There is a high risk that substances containing will be adsorbed and remain. Further, the substance containing Al adsorbed on the susceptor is close to the substrate when growing the active layer containing nitrogen, and thus reacts with the nitrogen compound raw material and impurities contained therein (for example, mainly water in the case of DMHy). Therefore, there is an extremely high risk of being incorporated into the active layer. Therefore, it is necessary to prevent the substance containing Al adsorbed on the susceptor from reacting when the active layer containing nitrogen is grown so that it is not taken in. Therefore, the luminous efficiency of the semiconductor light emitting device using the active layer containing nitrogen is improved. It can be said that it is extremely effective in preventing the decrease of

FIG. 4 is a view showing an example of the arrangement of a semiconductor light emitting device manufacturing apparatus according to the first embodiment of the present invention. Note that FIG.
Is a diagram showing a vertical cross section of a reaction chamber (growth chamber) of the MOCVD apparatus.

In the configuration example of FIG. 4, the reaction chamber is a vertical reaction tube, and a substrate for growing a semiconductor light emitting element and a susceptor for mounting the substrate are held on the stage. There is. The raw material gas introduced from the raw material gas supply port is introduced onto the substrate. The stage is provided with a heating mechanism by resistance heating, and the source gas chemically reacts with the surface of the substrate on the susceptor heated to a high temperature by the heating mechanism of the stage to grow a semiconductor layer.

Here, as shown in FIG. 5, the susceptor can be attached and detached from the stage, and after the stage is pulled out from the reaction chamber to the second chamber for transfer, the susceptor and the substrate mounted thereon are It can be transported and taken out through the sample chamber. Each chamber can be partitioned by, for example, a gate valve, and the sample chamber can be independently evacuated or purged with hydrogen or nitrogen. Thereby, the susceptor and the substrate can be transferred to the reaction chamber in a hydrogen atmosphere, for example.

A plurality of susceptors are prepared in the sample chamber, and as shown in FIG. 6A, a thin pole extends from a small hole in the lower part of the susceptor to lift the substrate. The transfer arm can move freely between the susceptors. This substrate transfer mechanism does not need to be only an arm, for example, as shown in FIG.
As described above, it is possible to use a transfer method using a vacuum chuck or the like.

The susceptor in the sample chamber can transfer any susceptor to the reaction chamber. That is, the substrate can be moved on an arbitrary susceptor without being exposed to the outside air in the sample chamber, and the arbitrary susceptor can be transported to the reaction chamber. Since the substrate does not have to be exposed to the outside air during transportation, contamination of the substrate and oxidation due to oxygen in the atmosphere are minimized.

In the first embodiment, the semiconductor light emitting device of FIG. 2 can be grown in the following steps. That is, first, the first semiconductor layer 202 containing Al is grown on the substrate 201. After the step of growing the semiconductor layer 202 containing Al is completed, the susceptor on which the substrate is placed is transported to the sample chamber, and the substrate is moved to another susceptor prepared in the sample chamber in advance. The susceptor prepared in the sample chamber has been sufficiently evacuated to remove the adsorbed gas in advance.When carrying it, it is possible to prevent contamination and oxidation of the substrate and susceptor by purging with, for example, hydrogen gas. I can. The substrate placed on the new susceptor is conveyed to the reaction chamber together with the susceptor, and subsequently, the intermediate layer 203 and the active layer 204 are grown. Then, the intermediate layer 203, Al
Growing a second semiconductor layer 205 including. At this time, the timing of exchanging the susceptor may be between the growth of the first semiconductor layer 202 containing Al and the end of the growth of the lower intermediate layer 203, for example, the growth of the lower intermediate layer 203. The growth may be interrupted midway and the susceptor may be replaced.

By using the above susceptor replacement step, it is possible to use a non-adsorbed susceptor instead of an adsorbed substance containing Al when the active layer is grown. As a result, it is possible to prevent the substance containing Al from coming into contact with the nitrogen compound raw material or the impurities contained in the nitrogen compound raw material and being taken into the active layer, and it is possible to grow a semiconductor light emitting device having a low threshold value.

In other words, the semiconductor light-emitting device manufacturing method and the semiconductor light-emitting device manufacturing apparatus according to the first embodiment provide a semiconductor layer containing Al between a substrate and an active layer containing nitrogen, and the nitrogen is added to the semiconductor layer. When growing the active layer containing Al and the semiconductor layer containing Al using a nitrogen compound raw material and an organometallic Al raw material, respectively, a susceptor for holding the substrate when growing the semiconductor layer containing Al and the nitrogen Different from the susceptor that holds the substrate when growing the active layer containing.

With this, it is possible to prevent the substance containing Al from coming into contact with the nitrogen compound raw material or the impurities contained in the nitrogen compound raw material and being taken into the active layer, and to grow a semiconductor light emitting device having a low threshold value. You can

In the semiconductor light emitting device manufacturing apparatus according to the first embodiment, while the semiconductor layer containing Al is being grown, the susceptor for growing the active layer containing nitrogen is kept in a separate room from the growth room. Then, after the growth of the semiconductor layer containing Al is completed, the susceptor for growing the active layer containing nitrogen and the susceptor grown with the semiconductor layer containing Al can be exchanged without exposing the substrate to the atmosphere. Have

FIG. 10 is a view showing a modified example of the semiconductor light emitting device manufacturing apparatus according to the first embodiment of the present invention. Note that FIG. 10 is a schematic view of a vertical cross section of the reaction chamber of the MOCVD apparatus as seen from the side.

In the configuration example of FIG. 10, the reaction chamber is a horizontal reaction tube, but the basic configuration is common to the configuration example of FIG. 4, and the same effect as that of the configuration example of FIG. 4 can be obtained. .

That is, in the apparatus shown in FIG. 10, the substrate for growing the semiconductor light emitting element and the susceptor for holding the substrate are mounted inside the object to be heated.
Here, the susceptor is made of, for example, carbon, and a recess for holding the substrate is provided on the susceptor. Further, the susceptor is formed so as to cover the body to be heated so that it can be attached and detached. The object to be heated is also made of carbon, and the susceptor and the object to be heated can be heated by, for example, induction heating.

In such a structure, the source gas introduced from the source gas supply port causes a chemical reaction on the substrate surface on the heated susceptor to grow the semiconductor layer. This susceptor can be attached to and detached from the object to be heated as shown in FIG. 11, and can be transferred to the sample chamber after being drawn out into the second chamber for transfer and then transferred together with the susceptor and the substrate mounted thereon. The sample chamber can be independently evacuated or purged with hydrogen or nitrogen. For example, the susceptor and the substrate can be transferred to the reaction chamber in a hydrogen atmosphere. A plurality of susceptors are prepared in the sample chamber, and the substrate on the susceptor can be moved onto any susceptor by a vacuum chuck or the like.

In the apparatus as described above, the semiconductor light emitting device having the structure shown in FIG. 2 can be grown in the same steps as described above.

As described above, the horizontal reaction tube is completely the same as the vertical reaction tube, and by using the step of exchanging the susceptor, it is not the susceptor in which the substance containing Al is adsorbed when the active layer is grown. It is possible to use a susceptor that does not contain Al and to prevent a substance containing Al from coming into contact with the nitrogen compound raw material or impurities contained in the nitrogen compound raw material and being taken into the active layer. Can grow.

Second Embodiment As described in the first embodiment, when a semiconductor light emitting device using an active layer containing nitrogen is grown, a susceptor adjacent to the substrate is grown before the growth of the active layer. When a substance containing Al is adsorbed, it reacts and is taken in when the active layer containing nitrogen is grown, and there is an extremely high risk of causing a decrease in luminous efficiency. In order to reduce this risk, in the second embodiment of the present invention, a detachable cover is provided as a means for making it difficult for the substance containing Al to be adsorbed to the susceptor.

FIG. 7 is a view showing an example of the arrangement of a semiconductor light emitting device manufacturing apparatus according to the second embodiment of the present invention. Note that FIG.
FIG. 3 is a schematic view of a vertical section of a reaction chamber of an MOCVD apparatus as seen from the side. In the configuration example of FIG. 7, the reaction chamber is a vertical reaction tube, and a substrate for growing a semiconductor light emitting device and a susceptor for holding the substrate are provided inside.

In such a structure, the source gas introduced from the source gas supply port forms a semiconductor layer by a chemical reaction on the surface of the substrate on the susceptor heated to a high temperature by, for example, resistance heating built in the stage below the susceptor. It is designed to grow.

By the way, in the second embodiment, the susceptor is covered with a removable cover except for the portion on which the substrate is placed (see FIG. 8). This cover is removable so as not to damage the atmosphere in the reaction chamber, and can be taken out of the reaction chamber. In this case, problems such as contamination and oxidation of the substrate do not occur before and after the cover is attached and detached. Also, the cover, except the exposed part of the substrate,
It is better to have a structure that covers almost the entire surface of the susceptor. In this case, when the Al-containing layer is grown while being covered with this cover, the Al-containing substance is hardly adsorbed to the susceptor.

As described above, a semiconductor light emitting element having high luminous efficiency can be manufactured by the method for manufacturing a semiconductor light emitting element or the apparatus for manufacturing a semiconductor light emitting element according to each of the above-described embodiments.

Further, in the present invention, a surface-emitting type semiconductor laser can be manufactured by the method for manufacturing a semiconductor light emitting element or the apparatus for manufacturing a semiconductor light emitting element according to each of the above-described embodiments. FIG. 9 is a diagram showing an example of a surface emitting semiconductor laser manufactured by the method for manufacturing a semiconductor light emitting device or the apparatus for manufacturing a semiconductor light emitting device according to the present invention. Referring to FIG. 9, this surface-emitting type semiconductor laser includes an n-type GaAs substrate 5
1, an n-type semiconductor multilayer mirror 52, a GaAs lower spacer layer 53, a GaInNAs / GaAs multiple quantum well active layer 54, a GaAs upper spacer layer 55, an AlAs layer 56, and a p-type semiconductor multilayer mirror 57 are sequentially arranged. Has been formed.

Here, the n-type semiconductor multilayer film reflecting mirror 52 is
n-type GaAs high refractive index layer and n-type Al _0.8Ga_0.2As low bending
Consists of distributed Bragg reflectors with alternating layers
Has been. Similarly, the p-type semiconductor multilayer film reflection mirror 57 also has a p-type
-Type GaAs high refractive index layer and p-type Al_0.8Ga_0.2As low refraction
It consists of distributed Bragg reflectors with alternating layers
ing.

The GaInNAs / GaAs multiple quantum well active layer 54 has a bandgap wavelength of 1.3 μm band. The GaAs lower spacer layer 53 to the GaAs upper spacer layer 55 constitute a λ resonator.

Then, the above laminated structure is cylindrically etched to reach the n-type semiconductor multilayer film reflecting mirror 52 to form a mesa structure. The mesa size is 30 μmφ. Then, the current confinement structure is formed by selectively oxidizing the AlAs layer 56 from the side surface where the surface is exposed by etching to form an AlO _x insulating region. In this case, the current is concentrated in the oxide opening region of about 5 μmφ by the AlO _x insulating region and injected into the active layer 54.

Further, a ring-shaped p-side electrode 58 is formed on the surface of the p-type semiconductor multilayer film reflecting mirror 57, and n-type GaAs is formed.
An n-side electrode 59 is formed on the back surface of the substrate 51.

In the surface emitting semiconductor laser having such a structure, the GaInNAs / GaAs multiple quantum well active layer 54
The light emitted by the upper and lower semiconductor multilayer film reflecting mirrors 52, 57
The laser light in the 1.3 μm band is reflected and amplified by the substrate 5
Emit in the direction perpendicular to 1.

In the surface-emitting type semiconductor laser having such a structure, the semiconductor multilayer film reflecting mirror 52 on the GaAs substrate 51.
As regards the AlGaAs / GaAs laminated type, the high-performance reflecting mirror can be manufactured most easily, and the electrical characteristics are good, so that it is easy to use. In fact, 0.85 μm band and 0.9
The 8 μm band VCSEL is actually manufactured and sold by using an AlGaAs / GaAs laminated semiconductor multilayer film reflecting mirror, and in the surface emitting semiconductor laser on the GaAs substrate,
It can be said that this AlGaAs / GaAs laminated type semiconductor multilayer film reflecting mirror is indispensable. However, conventionally, when a surface emitting semiconductor laser using an active layer containing nitrogen is grown by MOCVD and an attempt is made to form the reflecting mirror 52 of an AlGaAs / GaAs laminated type, the active layer 5 is formed for the above-mentioned reason.
4 was deteriorated, and an element having a low threshold current could not be obtained.

The steps of growing the surface emitting semiconductor laser shown in FIG. 9 were as follows. That is, first, the n-type semiconductor multilayer film reflecting mirror 52 is grown. During the growth of the n-type semiconductor multilayer film reflecting mirror 52, the reaction is performed by covering the susceptor with the cover. Then, the Al-containing substance is hardly adsorbed to the susceptor, and is almost adsorbed to the cover.

Next, the lower spacer layer 53 and the active layer 5 are formed.
Make 4 growth. At this time, I decided to remove the cover. The removed cover will be moved out of the reaction chamber system. By removing the cover, the substance containing Al is removed from the reaction chamber system together with the cover, so that it is possible to prevent the substance from being taken into contact with the nitrogen compound raw material or impurities contained in the nitrogen compound raw material. . In the apparatus of the second embodiment, the cover can be removed to move it to the outside of the reaction chamber system without impairing the atmosphere. Therefore, the step of removing the cover ends the growth of the layer containing Al. After that, it may be performed anywhere until the growth of the active layer 54 starts. For example, the step of removing the cover can be performed between the growth of the lower spacer layer 53 and the n-type semiconductor multilayer film reflecting mirror 52.

After that, the upper spacer layer 55 and the p-type semiconductor multilayer film reflecting mirror 57 are grown, and the crystal growth is completed. When growing the p-type semiconductor multilayer film reflecting mirror 57, the cover may be attached again. By reattaching it, it is possible to prevent the adsorption of the substance containing Al on the susceptor during the growth of the p-type semiconductor multilayer film reflecting mirror 57. Particularly when the semiconductor light emitting device is continuously grown, the substance containing Al adsorbed to the susceptor when growing the p-type semiconductor multilayer film reflection mirror 57 is desorbed from the susceptor during the next growth and activated. The p-type semiconductor multilayer film reflecting mirror 5 is likely to have a bad influence on the layer 54.
It is preferable to attach a cover also when growing 7. As described above, by using the manufacturing apparatus and the manufacturing method according to the present invention, even if the semiconductor multilayer film reflecting mirror 52 of AlGaAs / GaAs stack is used, the active layer 5 of GaInNAs or the like is formed.
It is possible to grow a low-threshold surface-emitting type semiconductor laser of No. 4.

As described above, the semiconductor light-emitting device manufacturing method and the semiconductor light-emitting device manufacturing apparatus according to the second embodiment of the present invention provide the semiconductor layer containing Al between the substrate and the active layer containing nitrogen. When the nitrogen-containing active layer and the Al-containing semiconductor layer are grown using a nitrogen compound raw material and an organometallic Al raw material, respectively, the susceptor holding the substrate covers a portion other than the portion directly holding the substrate. It has such a detachable cover, and has a mechanism for attaching the cover when growing the semiconductor layer containing Al and removing the cover when growing the active layer containing nitrogen.

Here, the detachable cover has a detachable mechanism with the susceptor loaded in the reaction chamber.

FIG. 12 is a view showing an example of the arrangement of a semiconductor light emitting device manufacturing apparatus according to the present invention. Note that FIG. 12 shows MOCVD.
It is the schematic which looked at the longitudinal section of the reaction chamber of an apparatus from the side. Figure 1
In the example of 2, the reaction chamber is a horizontal reaction tube.

In the apparatus shown in FIG. 12, the substrate for growing the semiconductor light emitting element and the susceptor for mounting the substrate are held in the growth chamber. The susceptor is made of, for example, carbon, and a recess for holding the substrate is provided on the susceptor.

The cover is made of, for example, quartz, and is formed so as to cover the susceptor so that it can be attached and detached (see FIG. 13).

The susceptor can be heated by induction heating, and the source gas introduced from the source gas supply port causes a chemical reaction on the substrate surface on the heated susceptor to grow a semiconductor layer. There is. The susceptor is attached to the supporting rod, and is used for the reaction chamber and the second transfer chamber.
The room can be moved in and out. In the second transfer chamber, the susceptor can be removed from the supporting rod, and the removed susceptor can be moved to and from the sample chamber together with the substrate and the cover.
The inside of each chamber can be shut off by, for example, a gate valve, and the inside can be adjusted to an arbitrary atmosphere. In this embodiment, the cover is simply put on the susceptor, and its attachment / detachment is first carried from the reaction chamber to the second carrying chamber,
After that, the susceptor and the substrate are detached from the supporting rod, transported to the sample chamber, and can be detached in the sample chamber by the cover attaching / detaching lever as shown in FIG.

In this device, the semiconductor light emitting device as shown in FIG. 2 was grown in the following steps.

That is, the first element containing Al on the substrate 201
The semiconductor layer 202 of is grown. After the step of growing the semiconductor layer 202 (eg, AlGaAs) containing Al is completed, the intermediate layer 203 (eg, GaAs) is grown halfway. Next, the growth is stopped once, the substrate and the susceptor are transported to the sample chamber, and the cover is removed. After that, it is conveyed to the reaction chamber again, and the remaining lower intermediate layer 203, active layer 204, and upper intermediate layer 203 are grown halfway. After that, the growth is stopped again, the sample is transferred to the sample chamber, the cover is attached, and then transferred to the reaction chamber again.
Growing a second semiconductor layer 205 including.

Since the cover is attached / detached by using the cover attachment / detachment lever without exposing the sample chamber to the atmosphere, it is possible to eliminate the influence of the substrate being contaminated or oxidized due to the atmosphere being opened.

By the steps as described above, it is possible to prevent the substance containing Al from coming into contact with the nitrogen compound raw material or the impurities contained in the nitrogen compound raw material and being taken into the active layer. The device was able to grow.

Further, in this embodiment, the step of attaching / detaching the cover can be carried out by being modified even if there is no cover attaching / detaching lever. At this time, the step of attaching and detaching the cover can be carried out by manually opening the sample chamber to the atmosphere. However, since the substrate is exposed to the atmosphere, it may be affected by oxidation. In this embodiment, the growth is interrupted in the middle of GaAs which is the intermediate layer.
Since GaAs is less likely to be oxidized than AlGaAs, if GaAs is used as the outermost surface instead of AlGaAs, the effect of oxidation due to atmospheric exposure for a short time can be reduced. As a result, the effect of opening to the atmosphere can be minimized.

As described above, the manual attachment / detachment of the cover is affected by opening to the atmosphere. However, since it is not necessary to prepare a cover attachment / detachment lever, the structure of the device is extremely simple. As a result, the present general MOCVD apparatus can be easily implemented in comparison. That is,
If the layout of the reaction chamber permits, this embodiment can be performed by simply making a cover that can be installed and transported. Generally, the MOCVD apparatus is an extremely expensive apparatus and cannot be easily modified beyond a certain extent. However, in the present embodiment, the present invention can be implemented at a low cost without making a large-scale modification. Also, since the cover attaching / detaching lever only needs to be attached to the sample chamber, it is not difficult to implement because this mechanism does not require so large-scale modification.

Further, according to the present invention, an optical transmission module using a surface emitting semiconductor laser manufactured by the method for manufacturing a semiconductor light emitting device or the apparatus for manufacturing a semiconductor light emitting device according to each of the above-described embodiments, or an optical transmission / reception module, Alternatively, an optical communication system can be constructed.

FIG. 15 is a diagram showing an example of the optical transmission module according to the present invention. 16 is a diagram showing an example of the optical transceiver module according to the present invention.

When the surface-emitting type semiconductor laser device according to the present invention is used in an optical communication system, since the surface-emitting type semiconductor laser device is low in cost, as shown in FIGS. An optical transmission module or an optical transmission / reception module in which a laser element, a receiving photodiode, and an optical fiber are combined can be obtained.

For example, a surface emitting laser using GaInNAs is an element that can obtain oscillation in the 1.2-1.3 μm band, and at these wavelengths, there is little loss with respect to a silica optical fiber. It is said that it is suitable as a light source for communication. Furthermore, when a fluorine-doped POF (plastic fiber) which has a low loss particularly in a long wavelength band of 1.3 μm and the like and a surface emitting laser using GaInNAs as an active layer are combined, the cost of the fiber is low, Since the diameter is large and the coupling with the fiber is easy and the mounting cost can be reduced, an extremely low-cost module can be realized. In addition, GaInNAs
Due to its excellent temperature characteristics, does not require a powerful cooling arrangement. Therefore, the cost for cooling can be reduced and an inexpensive optical communication module can be obtained.

According to the present invention, since an active layer containing high quality nitrogen can be grown, it becomes easier to manufacture the surface emitting semiconductor laser device as shown in FIG. High-performance long-wavelength surface-emitting type semiconductor laser devices for communication can be realized, and by using these devices,
Optical communication systems such as low-cost optical fiber communication systems and optical interconnection systems can be realized.

[0087]

As described above, according to the first and second aspects of the invention, the semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen is activated. When a layer and a semiconductor layer containing Al are grown using a nitrogen compound raw material and an organometallic Al raw material, respectively,
A semiconductor layer containing Al is grown by using a different susceptor for holding a substrate when growing a semiconductor layer containing l and a susceptor holding a substrate for growing an active layer containing nitrogen. At this time, it is possible to prevent the substance containing Al adsorbed on the susceptor from coming into contact with the nitrogen compound raw material or the impurities contained in the nitrogen compound raw material and being taken into the substrate when the active layer containing nitrogen is grown. Threshold semiconductor light emitting devices can be grown.

According to the invention of claim 3, Al
While growing the semiconductor layer containing, the susceptor for growing the active layer containing nitrogen is kept in a separate room from the growth room,
After the growth of the semiconductor layer containing Al is completed, the susceptor for growing the active layer containing nitrogen and the susceptor grown with the semiconductor layer containing Al can be exchanged without exposing the substrate to the atmosphere. Therefore, the susceptor can be replaced without exposing the substrate to the atmosphere during the growth of the semiconductor light emitting device, and it is possible to provide an apparatus that has the effect of claim 2 and can reduce the risk of contamination or oxidation of the substrate. .

According to the invention of claim 4, a semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing pre-nitrogen and the semiconductor layer containing Al are provided,
In a method for manufacturing a semiconductor light emitting device, which is grown using a nitrogen compound raw material and an organometallic Al raw material, respectively, the susceptor holding the substrate has a detachable cover that covers a portion other than the portion directly holding the substrate. , A cover is attached when the semiconductor layer containing Al is grown, and a cover is removed when the active layer containing nitrogen is grown, so that the Al adsorbed on the cover is included when the semiconductor layer containing Al is grown. When a substance grows an active layer containing nitrogen, it is possible to prevent the substance from coming into contact with a nitrogen compound raw material or impurities contained in the nitrogen compound raw material and being taken into a substrate, and to grow a low threshold semiconductor light emitting device. You can

According to the fifth aspect of the invention, a semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen and the semiconductor layer containing Al are each provided with nitrogen. In a semiconductor light emitting device manufacturing apparatus for growing a semiconductor light emitting device using a compound raw material and an organometallic Al raw material, a susceptor for holding a substrate has a detachable cover for covering a portion other than a portion for directly holding the substrate. Then
Since a cover is attached when growing a semiconductor layer containing Al, and a cover is removed when growing an active layer containing nitrogen, the Al adsorbed on the cover when the semiconductor layer containing Al is grown. -Containing substances can be prevented from being taken into the substrate by coming into contact with the nitrogen compound raw material or impurities contained in the nitrogen compound raw material during the growth of the active layer containing nitrogen. can do.

According to the sixth aspect of the invention, the detachable cover has a detachable mechanism with the susceptor loaded in the reaction chamber. It is possible to provide a device capable of removing the cover without exposing the substrate to the atmosphere and having the effect of claim 5, while reducing the risk of contamination or oxidation of the substrate.

According to the invention described in claim 7, the method for manufacturing a semiconductor light emitting device according to claim 1 or claim 4, or the method according to claim 2 or claim 3 or claim 5 or claim 6. Since it is a surface emitting semiconductor laser device characterized by being manufactured by the manufacturing apparatus for a semiconductor light emitting device described in the above, even if a semiconductor multilayer film reflecting mirror of AlGaAs / GaAs stack is used, an active layer containing N such as GaInNAs It is possible to grow (provide) a surface-emitting type semiconductor laser device having a low threshold.

According to the invention described in claim 8, the surface emitting semiconductor laser device according to claim 7 is used, which is an optical transmitter module.
It is possible to provide a low-cost and small-sized optical transmission module that uses a surface-emitting type semiconductor laser device that uses a high-quality active layer containing N such as As and uses a material that is well matched to an optical fiber.

According to the invention of claim 9, the surface emitting semiconductor laser device of claim 7 is used, which is an optical transceiver module.
It is possible to provide a low-cost and small-sized optical communication module that uses a surface emitting semiconductor laser device using a high-quality active layer containing N such as NAs and using a material that is well matched with an optical fiber as a light source.

According to the invention of claim 10, there is provided an optical communication system characterized by using the surface-emitting type semiconductor laser device of claim 7, so that GaInN is used.
It is possible to provide a low-cost and small-sized optical communication system that uses a surface emitting semiconductor laser device using a high-quality active layer containing N such as As and using a material that is well matched with an optical fiber.

[Brief description of drawings]

FIG. 1 is a diagram showing a room temperature photoluminescence spectrum of a GaInNAs / GaAs double quantum well structure including a GaInNAs quantum well layer and a GaAs barrier layer, which is manufactured by an MOCVD apparatus by the inventor of the present application.

FIG. 2 is a diagram showing an example of a semiconductor light emitting element in which a semiconductor layer containing Al is provided between a substrate and a semiconductor layer containing nitrogen.

3 shows an example of the semiconductor light emitting device of FIG. 2 in which the first semiconductor layer and the second semiconductor layer are AlGaAs, the intermediate layer is GaAs, and the active layer containing nitrogen is GaInNAs / G.
It is a figure which shows the depth direction distribution of nitrogen (N) density | concentration and oxygen (O) density | concentration when the semiconductor light-emitting device comprised as an aAs2 quantum well structure was formed using one epitaxial growth apparatus (MOCVD). .

FIG. 4 is a diagram showing a configuration example of an apparatus for manufacturing a semiconductor light emitting device according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining the transfer of a susceptor and a substrate.

FIG. 6 is a diagram for explaining a substrate transfer mechanism.

FIG. 7 is a diagram showing a configuration example of a semiconductor light emitting device manufacturing apparatus according to a second embodiment of the present invention.

FIG. 8 shows a susceptor adapted to be covered by a removable cover.

FIG. 9 is a diagram showing an example of a surface-emitting type semiconductor laser manufactured by the method for manufacturing a semiconductor light emitting device and the apparatus for manufacturing a semiconductor light emitting device according to the present invention.

FIG. 10 is a diagram showing a modification of the semiconductor light emitting device manufacturing apparatus according to the first embodiment of the present invention.

FIG. 11 is a diagram for explaining the transportation of the susceptor.

FIG. 12 is a diagram showing a configuration example of a semiconductor light emitting device manufacturing apparatus of the present invention.

FIG. 13 is a view showing a removable cover on the susceptor.

FIG. 14 is a view for explaining how to remove the cover with the cover attaching / detaching lever.

FIG. 15 is a diagram showing an example of an optical transmission module according to the present invention.

FIG. 16 is a diagram showing an example of an optical transmission module according to the present invention.

[Explanation of symbols]

51 n-type GaAs substrate 52 n-type semiconductor multilayer film reflection mirror 53 GaAs lower spacer layer 54 GaInNAs / GaAs multiple quantum well active layer 55 GaAs upper spacer layer 56 AlAs layer 57 p-type semiconductor multilayer film reflection mirror 58 p-side electrode 59 n side Electrode 201 Substrate 201 First semiconductor layer 203 Intermediate layer 204 Active layer 205 Second semiconductor layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Takahashi             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Shunichi Sato             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 5F045 AA04 AB09 AB17 AB18 AB19                       AF04 BB05 BB06 BB08 BB16                       CA12 EB08 EB11 EM01                 5F073 AA74 AB16 BA01 CA07 CB02                       DA05 DA35

Claims (10)

[Claims] 1. A semiconductor layer containing Al is provided between a substrate and an active layer containing nitrogen, and the active layer containing nitrogen and the Al are provided.
In a method of manufacturing a semiconductor light emitting device, wherein a semiconductor layer containing Al is grown using a nitrogen compound raw material and an organometallic Al raw material, respectively, a susceptor for holding a substrate when growing the Al-containing semiconductor layer, and A method for manufacturing a semiconductor light emitting device, characterized in that a susceptor that holds a substrate when growing an active layer is different. 2. A semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen and the Al are provided.
In a semiconductor light-emitting device manufacturing apparatus for growing a semiconductor layer containing Al by using a nitrogen compound raw material and an organometallic Al raw material, respectively, and a susceptor for holding a substrate when growing the Al-containing semiconductor layer; An apparatus for manufacturing a semiconductor light emitting device, wherein a susceptor that holds a substrate when growing an active layer is different. 3. The semiconductor light-emitting device manufacturing apparatus according to claim 2, wherein the susceptor for growing the active layer containing nitrogen is kept in a separate room from the growth chamber while growing the semiconductor layer containing Al. After the growth of the semiconductor layer containing Al is completed, the susceptor for growing the active layer containing nitrogen and the susceptor having grown the semiconductor layer containing Al can be exchanged without exposing the substrate to the atmosphere. An apparatus for manufacturing a semiconductor light emitting element, which is characterized in that 4. A semiconductor layer containing Al is provided between a substrate and an active layer containing nitrogen, and the active layer containing nitrogen and the Al are provided.
In a method for manufacturing a semiconductor light emitting device, in which a semiconductor layer containing a is grown using a nitrogen compound raw material and an organic metal Al raw material, respectively, the susceptor for holding the substrate is detachable so as to cover a portion other than the portion directly holding the substrate. A method for manufacturing a semiconductor light emitting device, characterized in that the cover is attached when growing the semiconductor layer containing Al, and the cover is removed when growing the active layer containing nitrogen. 5. A semiconductor layer containing Al is provided between the substrate and the active layer containing nitrogen, and the active layer containing nitrogen and the Al are provided.
In a semiconductor light-emitting device manufacturing apparatus in which a semiconductor layer containing is grown using a nitrogen compound raw material and an organic metal Al raw material, respectively, the susceptor for holding the substrate is detachable so as to cover a portion other than the portion directly holding the substrate. A semiconductor light-emitting device having a transparent cover and having a mechanism for attaching the cover when growing the semiconductor layer containing Al and removing the cover when growing the active layer containing nitrogen. Device manufacturing equipment. 6. The semiconductor light emitting device manufacturing apparatus according to claim 5, wherein the detachable cover has a detachable mechanism with the susceptor loaded in the reaction chamber. Light emitting device manufacturing equipment. 7. The method for manufacturing a semiconductor light emitting device according to claim 1 or claim 4, or claim 2 or claim 3.
Alternatively, a surface emitting semiconductor laser device manufactured by the semiconductor light emitting device manufacturing apparatus according to claim 5 or 6. 8. An optical transmitter module using the surface-emitting type semiconductor laser device according to claim 7. 9. An optical transceiver module comprising the surface-emitting type semiconductor laser device according to claim 7. 10. An optical communication system comprising the surface-emitting type semiconductor laser device according to claim 7.