JP2002344069A - Device for manufacturing semiconductor laser element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for manufacturing a semiconductor laser element that can produce high output and long service life semiconductor laser element, when manufacturing a semiconductor laser element with suppressed generation of COD. SOLUTION: This manufacturing device is provided with a cleaving chamber 11, where a laminated structure made of semiconductor material is cleaved, and working to form the cleavage end face of a resonator is conducted, a crystal growth chamber 12 where a compound semiconductor is subject to epitaxial crystal growth on the cleavage end face of the resonator to form an end face growth layer, and a relay chamber 15 for connecting the cleaving chamber 11 and crystal growth chamber 12. The three chambers 11, 12 and 15 are provided with an atmospheric gas supply part 20 for supplying a high-purity inert gas, such as an highly purified N2 gas of 20 ppb or lower in concentration of oxygen and 20 ppb or lower in moisture concentration, an inert gas supply line 27, a material gas supply line 30, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for manufacturing a semiconductor laser device.

[0002]

2. Description of the Related Art A semiconductor laser device is usually manufactured as follows. First, a lower cladding layer made of, for example, n-AlGaAs is formed on a semiconductor substrate made of, for example, n-GaAs by using an epitaxial crystal growth method.
For example, a lower light confinement layer made of non-doped AlGaAs, for example, an active layer having a multiple quantum well structure made of InGaAs / GaAs, for example, an upper light confinement layer made of non-doped AlGaAs, for example, an upper light confinement layer made of p-AlGaAs, and, for example, p-GaAs Are laminated in this order to produce a slab-like laminated structure.

Next, after processing the upper surface of the laminated structure into, for example, a ridge shape, for example, Ti / Pt / Au
To form an upper electrode (p-type electrode) that is in ohmic contact with the cap layer. On the back surface of the semiconductor substrate, for example, AuGeNi / Au is deposited to form a lower electrode (n-type electrode). Then, the laminated structure is cleaved to have a predetermined resonator length to form a cleavage end face of the resonator. Usually, a low-reflection film is formed on one end face of the resonator, and a high-reflection film is formed on the other end face using a dielectric material such as silicon nitride to manufacture a target semiconductor laser device.

In the field of optical communication systems, the field of optical information recording such as optical disks, the field of laser printers and laser processing, the field of solid-state laser excitation, and the field of wavelength conversion light sources such as SHG, Conventionally, a high-output semiconductor laser device has been used. In recent years, demands for higher output of the semiconductor laser device have been increasing day by day.

For example, in the field of optical communication systems,
In the case of an optical amplifier (Er Doped Fiber Amplifier; EDFA) using an erbium-doped fiber (Er Doped Fiber; EDF) put into practical use in the early 1990s,
At the beginning of practical use, the required output of the semiconductor laser device for the excitation light source was at most several tens of mW. However, recent Wavelength Division Multiplexing (Wavelength Division Mult)
With the rapid progress of iplexing (WDM) technology and the like, a high output exceeding 100 mW is now required.
At the same time, there is also a demand for driving reliability of driving at such a high output for about one million hours.

[0006] Among the factors that limit the increase in the output of a semiconductor laser device, the most important factor is the catastrophic optical damage (Catastrophic Optical Damage) at the cleavage end face of the resonator.
age; COD). This COD is obtained by positive feedback based on a repetition of a series of processes of light absorption at the cleavage end face of the resonator → temperature rise at the end face → reduction of the band gap of the semiconductor material constituting the active layer at the end face → increase of light absorption. Occurs.

[0007] The most effective measure for suppressing such COD generation is to epitaxially grow a semiconductor material having a larger band gap than the semiconductor material forming the active layer on the cleavage end face of the resonator. is there. For example, Japanese Patent Application Laid-Open No. 8-32167 discloses that after forming an upper electrode and a lower electrode in the above-described laminated structure, the entire structure is cleaved,
A method for performing the above-described end face growth on the cleavage plane is disclosed. Therefore, in this method, since the semiconductor material to be grown on the end face is also formed on the electrode, it is necessary to promote the end face growth in a low-temperature environment in which an abnormal reaction does not occur between the two. Becomes

Incidentally, for example, when the active layer of the laminated structure is made of Al
When composed of a semiconductor material containing, since Al is a material that is easily oxidized, when the laminated structure is cleaved in the air, the cleaved surface adsorbs oxygen and moisture in the air and reacts with active Al. As a result, a very strong Al oxide film is formed on the cleavage plane. In this state, when the end face growth is performed in the above-described low temperature environment, abnormal growth occurs due to the low temperature epitaxial crystal growth of the semiconductor material. As a result, an epitaxial crystal growth layer containing many defects is formed on the end face. Therefore, there is a problem that new light absorption occurs on the growth layer.

Incidentally, such a problem may be sometimes solved by removing the oxide film on the cleavage plane. Generally, as in the case of removing an oxide film from a semiconductor substrate, for example, a carrier gas or the like is brought into contact with the oxide film at an appropriate temperature and the oxide film can be removed by its reducing action. At a growth temperature equal to or higher than that temperature, the surface of the semiconductor substrate is clean, so that the quality of the semiconductor layer formed thereon by epitaxial crystal growth is ensured.

However, since the epitaxial growth is performed at a low temperature in the end face growth, there is a problem that even if the above-mentioned oxide film is removed at a lower temperature, the removal of the oxide film cannot be expected. For this reason, when performing the work of cleaving the laminated structure made of the semiconductor material to form the cleavage end face of the resonator and the work of epitaxially growing a compound semiconductor on the cleavage end face of the resonator, the following FIG. Such a semiconductor laser device manufacturing apparatus is used.

That is, as shown in FIG. 6, in a conventional semiconductor laser device manufacturing apparatus, a lamination structure made of a semiconductor material is cleaved using a cleavage apparatus (not shown), and the cleavage end face of the resonator is cut. A cleavage chamber 41 is provided as a working chamber for performing the forming operation. Further, a crystal growth apparatus 42 for performing an operation of epitaxially growing a compound semiconductor on the cleavage end face of the resonator formed in the cleavage chamber 41 is provided physically independently of the cleavage chamber 41.

The cleavage chamber 41 is provided with a glove 43 for inserting a hand during a manual operation of the cleavage device and other operations. Also, the cleavage chamber 41
Is provided at one end with a front chamber 44 as a carry-in path for carrying the laminated structure made of the semiconductor material formed in the previous step into the cleavage chamber 41. Similarly, the crystal growth device 42
A front chamber 45 is also provided at one end as a carry-in path for carrying the bar of the semiconductor laser element, which has been cleaved in the cleavage chamber 41, into the crystal growth apparatus 42.

The cleavage chamber 41 and the crystal growth device 4
2, and an atmosphere gas supply unit for supplying an inert gas such as N ₂ (nitrogen) gas or Ar (argon) gas are installed in the front chambers 44 and 45. That is, the cleavage chamber 41
An inert gas supply line 46 for supplying an inert gas to one of the chambers is connected to a front chamber 44 via a valve 47, and a valve 48 and a vacuum pump 4 are connected to the other.
Exhaust line 50 is connected via 9.

An inert gas supply line 46 is connected to one side of the cleavage chamber 41 via a valve 51, and an exhaust line 53 is connected to the other side of the cleavage chamber 41 via a valve 52. Supplies an inert gas into the cleavage chamber 41 through a valve 51 from the cleavage chamber 4.
The atmosphere in 1 is exhausted to an exhaust line 53 via a valve 52.

As in the case of the front chamber 44, an inert gas supply line 54 for supplying an inert gas to one of the front chambers 45 provided to the crystal growth apparatus 42 is provided through a valve 55. The other end is connected to an exhaust line 58 via a valve 56 and an exhaust blower 57.
The crystal growth apparatus 42 has a source gas supply line 59 for supplying various source gases necessary for epitaxially growing a compound semiconductor on one side thereof.
., 63 are connected. And
These source gas supply lines 59 include an inert gas supply line for supplying an inert gas for replacing the atmosphere in the crystal growth apparatus 42 before the epitaxial crystal growth. An exhaust line 66 is connected to the other end via a valve 64 and an exhaust blower 65.

As described above, in the conventional semiconductor laser device manufacturing apparatus, the atmosphere in each of the cleavage chamber 41 for performing the cleavage operation and the front chamber 44 for carrying in and out of the cleavage chamber is controlled by the inert gas supply line 46. The atmosphere in each of the crystal growth apparatus 42 and the front chamber 45 for carrying in and out of the crystal growth apparatus 42 immediately before performing the epitaxial crystal growth operation is replaced with the source gas supply line 59 and the inert gas. The replacement with the inert gas supplied from the supply line 54 suppresses the oxidation of the cleavage end face of the resonator, and the end face growth layer formed by the epitaxial crystal growth method in the crystal growth apparatus 42 has high quality with few defects. Crystal film.

[0017]

However, in the above-described conventional semiconductor laser device manufacturing apparatus, the cleavage chamber 4
1 is performed in an atmosphere replaced with an inert gas, and the cleavage chamber 41 and the crystal growth are grown in the crystal growth apparatus 42 even though the atmosphere immediately before the epitaxial crystal growth work is also replaced with the inert gas. Since each of them is physically independent of the apparatus 42, even when the transfer from the cleavage chamber 41 to the crystal growth apparatus 42 is carried out for a very short time, the cleavage end face of the resonator is kept in the atmosphere. May be exposed.

As a result, the cleavage end face of the resonator adsorbs and reacts with oxygen and moisture in the atmosphere to form an oxide film, and abnormal growth occurs during epitaxial crystal growth in the crystal growth apparatus 42. Happens. As a result, an epitaxial crystal growth layer containing many defects is likely to be formed on the cleavage end face of the resonator, and this end face growth layer causes new light absorption, thereby deteriorating high output characteristics and shortening the life. Occurs.

Therefore, the present invention solves the above-mentioned problems in producing a semiconductor laser device in which the generation of COD is suppressed by growing a compound semiconductor at low temperature epitaxial crystal on a cleavage plane of a laminated structure made of a semiconductor material. It is another object of the present invention to provide a semiconductor laser device manufacturing apparatus capable of realizing a semiconductor laser device having a high output and a long life.

[0020]

According to the present invention, there is provided an apparatus for manufacturing a semiconductor laser device, comprising: a working chamber for performing a predetermined processing on a semiconductor substrate; and an epitaxial crystal growing apparatus for performing a predetermined processing on the semiconductor substrate in the working chamber. A crystal growth chamber to be performed, a relay chamber connecting the work chamber and the crystal growth chamber, and an atmosphere gas supply unit for supplying a high-purity inert gas to the work chamber, the crystal growth chamber, and the relay chamber. It is characterized by.

In the semiconductor laser device manufacturing apparatus, the working chamber is a cleavage chamber provided with a cleavage device for cleaving the laminated structure made of the semiconductor material to form a cleavage end face of the resonator, and the crystal growth chamber is provided. The crystal growth chamber is preferably a crystal growth chamber in which a compound semiconductor is epitaxially grown on a cleavage end face of a resonator formed in the cleavage chamber to form an end face growth layer.

[0022]

(First Embodiment) FIG. 1 is a schematic view showing an apparatus for manufacturing a semiconductor laser device according to a first embodiment of the present invention. As shown in FIG. 1, in a semiconductor laser device manufacturing apparatus according to the present embodiment, a cleavage structure (not shown) is used to cleave a laminated structure made of a semiconductor material as a working chamber to cleave a resonator. A cleavage chamber 11 for forming an end face is provided, and a crystal growth chamber 12 for forming a facet growth layer by epitaxially growing a compound semiconductor on a cleavage end face of a resonator formed in the cleavage chamber 11. Is installed.

The cleaving chamber 11 is provided with a glove 13 for inserting a hand when the cleaving device is manually operated or, for example, a bar is arranged on a tray. Further, at one end of the cleavage chamber 11, a front chamber 14 is provided as a carry-in path for carrying a stacked structure made of a semiconductor material having electrodes formed on the upper surface and the lower surface in a previous step into the cleavage chamber 11. In addition, a relay chamber 15 is provided between the cleavage chamber 11 and the crystal growth chamber 12 as a transfer path connecting the two.

The pre-chamber 14, the cleavage chamber 11, the relay chamber 15, and the crystal growth chamber 12 each have a low-concentration atmosphere gas of oxygen and moisture, for example, a concentration of 1 ppm of oxygen and moisture.
An atmosphere gas supply unit for supplying a high-purity inert gas such as N ₂ or Ar purified to a lower value and high purity is provided for each. That is, the front chamber 14 has an inert gas supply line 16 as an atmosphere gas supply unit on one side.
Is connected via a valve 17a, and the valve 1 is connected to the other side.
An exhaust line 19 is connected via the vacuum pump 7 and the vacuum pump 18. In this manner, the front chamber 14 has a function of replacing the inside atmosphere with the high-purity inert gas supplied from the inert gas supply line 16.

The atmosphere gas supply unit 20 of the cleavage chamber 11
As shown by a broken line in FIG. 1, an inert gas pressurizing line 21 for supplying a high-purity inert gas, a control valve 22a for controlling the amount of the high-purity inert gas flowing into the cleavage chamber 11, and a high-purity inert gas A purifier 23 for purifying by removing impurities mixed in the inert gas, a gas flow meter 24 for displaying a flow rate of the high-purity inert gas, valves 17c and 17d, a circulation blower for circulating the high-purity inert gas. 25, a control valve 22b for controlling the discharge amount from the cleavage chamber 11, and a pressure reducing line 26.

The purifying device 23 used here includes:
Various devices can be considered, such as a method of removing impurities and the like using a filter and a method of removing impurities and the like using a catalyst, but any type of device may be used. Then, the inert gas pressurizing line 2 is
1 to purification device 23, gas flow meter 24, and valve 17
c, the high-purity inert gas is supplied into the cleavage chamber 11 and the high-purity inert gas in the cleavage chamber 11 is supplied to the valve 1.
7d and return to the purifier 23 via the circulation blower 25,
Therefore, after performing a purification process for removing impurities and the like, the purified high-purity inert gas is circulated into the cleavage chamber 11 again via the gas flow meter 24 and the valve 17c. . Further, of the atmosphere in the cleavage chamber 11, gases other than those circulated into the cleavage chamber 11 via the purification device 23 and the like are reduced in pressure by the pressure reducing line 26 through the control valve 22 b.
It is designed to be exhausted.

In addition, an inert gas supply line 27 as an atmosphere gas supply unit is connected to one end of the relay chamber 15 via a valve 17e, and an exhaust line 29 is connected to the other end via a valve 17f and an exhaust blower 28. Is connected, and the internal atmosphere is replaced by a high-purity inert gas supplied from an inert gas supply line 27.

A source gas supply line 30 for supplying various source gases necessary for epitaxially growing a compound semiconductor on one side of the crystal growth chamber 12 is provided through valves 17g, 17h,..., 17j. It is connected. In these source gas supply lines 30, an atmosphere for replacing the atmosphere in the crystal growth chamber 12 before the epitaxial crystal growth or an atmosphere for replacing the source gas in the crystal growth chamber 12 after the epitaxial crystal growth is provided. An inert gas supply line as a gas supply unit is included. An exhaust line 32 is connected to the other side via a valve 17k and an exhaust blower 31.

Further, the cleavage chamber 11 is provided with a pressure sensor 33 with a contact for detecting a pressure change in the chamber.
Then, the control valves 22a and 22b which have received the signal from the pressure sensor 33 control the flow rate of the high-purity inert gas into the cleavage chamber 11 and the discharge rate from the cleavage chamber 11 to the decompression line 26, respectively. It has become. next,
A process of manufacturing a semiconductor laser device using the semiconductor laser device manufacturing apparatus of FIG. 1 will be described with reference to FIGS.

FIG. 2 is a perspective view showing a laminated structure made of a semiconductor material before cleavage which is carried into the apparatus for manufacturing the semiconductor laser device of FIG. 1, and FIG. 3 is an apparatus for manufacturing the semiconductor laser element of FIG. Ion mass spectroscopy (Secondar) performed near the cleavage end face of a semiconductor laser device fabricated using
FIG. 4 is a graph showing a measurement result of the Ion Mass Spectroscopy (SIMS), and FIG. 4 is a graph showing a measurement result of the SIMS performed on the vicinity of the cleavage end face of the semiconductor laser device manufactured for comparison with the present embodiment. is there.

First, using a predetermined crystal growth apparatus or the crystal growth chamber 12 shown in FIG.
An epitaxial crystal growth method such as Organic Chemical Vapor Deposition (Organic Chemical Vapor Deposition) is applied, and as shown in FIG. 2, a 3 μm thick n-AlGaAs substrate is formed on an n-GaAs substrate 1. Lower cladding layer 2, 30 nm thick made of non-doped AlGaAs
Lower optical confinement layer 3, undoped InGaAs / Ga
An active layer 4 having a thickness of 7 nm and having a lattice mismatched multiple quantum well structure in which As is stacked in order, a non-doped AlGaAs
30 nm thick upper light confinement layer 5, made of p-AlG
a 2 μm-thick upper cladding layer 6 made of aAs and p
A slab-like laminated structure having a laser oscillation function is formed by sequentially laminating the cap layers 7 made of -GaAs.

Subsequently, photolithography and etching are performed on the cap layer 7 on the upper surface of the laminated structure to process it into a ridge shape. In addition, Si ₃
After forming the protective film 8 made of N ₄ , the top portion of the ridge is removed by etching to expose the cap layer 7,
i / Pt / Au is sequentially vapor-deposited to form an upper electrode 9, and after polishing the back surface of the substrate 1, AuGeNi / A
The lower electrode 10 is formed by sequentially depositing u.

Next, the laminated structure made of the semiconductor material shown in FIG. 2 manufactured as described above is carried into the front chamber 14 of the semiconductor laser device manufacturing apparatus shown in FIG.
At this time, the front room 14, the cleavage room 11, the relay room 15,
And an inert gas supply line 16 in the crystal growth chamber 12,
A high-purity inert gas is supplied from the atmosphere gas supply unit 20, the inert gas supply line 27, the source gas supply line 30, and the like, and each chamber is filled.

The high-purity inert gas used here is set to a concentration of less than 1 ppm in both oxygen and moisture. If the concentration of oxygen and moisture in the high-purity inert gas is higher than 1 ppm, for example, if the semiconductor material forming the laminated structure contains Al such as AlGaAs or AlGaInP that has a strong bond with oxygen, the cleavage is performed. This is because the surface is rapidly oxidized. In the present embodiment, as such a high-purity inert gas, for example, N ₂ gas purified to a high purity with an oxygen concentration of 20 ppb or less and a water concentration of 20 ppb or less is used.

[0035] Then, in the front chamber 14 which carries the stacked structure shown in FIG. 2, to a purity of the N ₂ gas to fill the chamber is the purity and the same level of N ₂ gas to fill the cleavage chamber 11 After performing the replacement process, the stacked structure made of the semiconductor material shown in FIG. 2 is carried into the cleavage chamber 11 from the front chamber 14. In addition, N ₂ gas as a high-purity inert gas is supplied into the cleavage chamber 11 by the atmosphere gas supply unit 2.
0, the purifier 23
And supplied through a circulation flow blower 25 and a purifying device 23 such as a filter system or a catalyst system, etc., so that the oxygen concentration in the room is always 20 ppb or less and the water concentration is always It is managed to be 20 ppb or less.

Then, a hand is inserted into the glove 13 installed in the cleavage chamber 11, and the cleavage device in the chamber is manually operated to cleave the laminated structure shown in FIG. 2 to the designed resonator length. I do. Thus, the bar of the semiconductor laser device is manufactured, and the cleavage plane is exposed to form the cleavage end face of the resonator. In this case, the cleavage operation oxygen concentration as in the above laminated structure is 20ppb or less, the water concentration is carried out in an N ₂ gas atmosphere is controlled to be below 20ppb, oxidation of the cleavage facet of the cavity Is sufficiently suppressed.

When inserting a hand into the glove 13,
The pressure in the cleavage chamber 11 fluctuates. However, this cleavage chamber 1
1 is sensed by a pressure sensor 33 provided with a contact, and the control valves 22a and 22b which have received the signal from the pressure sensor 33 determine the amount of high-purity inert gas flowing into the cleavage chamber 11 and the cleavage chamber 11 Even if the cleavage device is manually operated by inserting a hand into the glove 13 to control the discharge amount from the inside, the inside of the cleavage chamber 11 is always kept at a constant pressure, for example, 100 to 1500 Pa. You. However, if the pressure becomes higher than this, there is a possibility that the seal portion is adversely affected. In this way, it is possible to easily perform an internal operation using the glove 13 and a hand at that time.

Next, the bar of the semiconductor laser device, which has been cleaved in the cleavage chamber 11, is set on a dedicated jig and transported to the crystal growth chamber 12 via the relay chamber 15. At the time of this transfer, the inside of the relay room 15 which passes
Similarly to the inside of the cleavage chamber 11, since it is filled with high-purity purified N ₂ gas having an oxygen concentration of 20 ppb or less and a water concentration of 20 ppb or less, it is not exposed to an atmosphere containing a large amount of oxygen and moisture. Therefore, even during transfer from the cleavage chamber 11 to the crystal growth chamber 12 via the relay chamber 15, oxidation of the cleavage end face of the resonator is sufficiently suppressed.

Also, in the crystal growth chamber 12 into which the bar of the semiconductor laser element has been carried in, before the epitaxial crystal growth, the high purity inert gas supplied from one of the source gas supply lines 30 is replaced. Therefore, the oxidation of the cleavage end face of the resonator before the start of epitaxial crystal growth in the crystal growth chamber 12 is sufficiently suppressed.

Next, in the crystal growth chamber 12, a desired source gas is introduced from the source gas supply line 30 by applying, for example, the MOCVD method or the molecular beam epitaxial growth method, and the compound semiconductor is epitaxially removed from the cleavage end face of the resonator. Crystal growth is performed to form an end face growth layer.
In the present embodiment, epitaxial growth of InGaP is performed, for example, at a temperature of 400 ° C. to form an end face growth layer.

The compound semiconductor used for the edge growth may be any material other than InGaP, such as InGaAsP or GaAs, as long as a high quality crystal film can be formed at a relatively low growth temperature. Preferably, it is not present. In this manner, an end face growth layer is formed on the cleavage end face of the resonator. The oxidation of the cleavage end face is sufficiently suppressed both in the cleavage chamber 11 where the cleavage operation is performed and in the relay chamber 15 which is passed during the transfer. Therefore, the end face growth layer formed on the cleaved end face by continuous epitaxial crystal growth in the crystal growth chamber 12 becomes a high-quality crystal film with few defects.

Next, the bar of the semiconductor laser device after the completion of the epitaxial crystal growth operation in the crystal growth chamber 12 is carried into the relay chamber 15 again, where N ₂ is filled.
After the substitution process is performed until the purity of the gas reaches the same level as the purity of the N ₂ gas filling the cleavage chamber 11, the gas is further carried into the cleavage chamber 11. As described above, the relay room 15 includes the cleavage room 11.
Accessible from both the side and the crystal growth chamber 12,
Since it has the same replacement function as the front chamber 14, when the bar of the semiconductor laser element is transferred from the crystal growth chamber 12 to the cleavage chamber 11 via the relay chamber 15, for example, the bar used in the crystal growth chamber 12 is used. No source gas such as H ₂ (hydrogen) gas flows into the cleavage chamber 11 via the relay chamber 15.

It should be noted that, for example, InGa
After the end face growth layer made of P is formed, there is no influence of oxidation. Therefore, if an exit with a door that can be carried out to the outside is separately provided in the relay room 15, through the cleavage chamber 11 It is also possible to take out directly from the relay room 15 to the outside without performing. The present inventors performed SIMS on the vicinity of the cleaved end face of the semiconductor laser device manufactured as described above, and obtained results as shown in the graph of FIG.

For comparison with this embodiment, FIG.
The cleavage operation in the cleavage chamber 41 is performed using an apparatus for manufacturing a semiconductor laser device shown in FIG.
In a working atmosphere of pm, the SIMS near the cleavage end face of the semiconductor laser device when transported from the cleavage chamber 41 to the crystal growth apparatus 42 through the air for a short time was also measured. The results are shown in the graph of FIG.

As is clear from comparison between the graphs of FIGS. 3 and 4, the semiconductor laser device of the present embodiment has a remarkably reduced oxygen amount in the vicinity of the cleavage end face of the resonator as compared with the comparative example. ing. That is, the inside of the cleavage room 11 and the relay room 1
The effect of controlling the oxygen concentration and the water concentration in 5 to low concentrations is obvious. In an environment of a temperature of 25 ° C., both the semiconductor laser device according to the present embodiment and the semiconductor laser device of the comparative example were oscillated at an optical output of 300 mW, and the MTTF (Mean Time to Failure) at that time was measured. As a result, the MTTF of the semiconductor laser device according to the present embodiment was 5 × 10 ⁷ hr, and the MTTF of the semiconductor laser device of the comparative example was 1 × 10 ⁷ hr.

As is clear from this, it was confirmed that the semiconductor laser device according to the present embodiment was excellent in the effect of suppressing COD, had a long service life, and had high driving reliability. In the first embodiment, the case where the working chamber is the cleavage chamber 11 provided with the cleavage device has been described. However, the working chamber according to the present invention is not limited to the cleavage chamber 11, and the crystal growth chamber is not limited thereto. The present invention can be widely applied to a process for processing a semiconductor substrate in a stage prior to the epitaxial crystal growth in Step 12. This means
The same applies to the second embodiment described below.

A glove 13 is provided in the cleavage chamber 11 serving as a working chamber, and a cleavage device in the room is manually operated. In the case where the operations such as transfer and bar setting work are automated and no manual operation is required, the cleavage chamber 11
It is not necessary to install the glove 13 in the glove box. When the glove 13 is not set in the cleavage chamber 11 as described above, the pressure in the cleavage chamber 11 does not fluctuate when the hand is inserted into the glove 13, and therefore, the pressure sensor 33 for sensing the fluctuation of the pressure. Also, the necessity of attaching the same is reduced.

In the first embodiment, the cleavage
Highly purified N in the opening 11 _TwoGas supply
In addition to the active gas pressurizing line 21, a circulation blower 25 and purification
A device 23 is attached, and high-purity N_TwoCirculate gas
In the case of a circulating supply system that is designed to supply cyclically
As described above, N into the cleavage chamber 11_TwoGas supply
The method is not limited to this circulation supply system. An example
For example, from the inert gas supply line 27 directly to the relay room 15
N_TwoAdopts a continuous supply system that continuously supplies gas
May be. However, when the circulation supply method is adopted,
Higher purity of N than in the case of continuous feeding method_TwoMoth
To reduce costs and contribute to cost reduction.
Will be possible.

In the case of employing the continuous supply method, it is not necessary to install a purifier when using a gas source for supplying highly purified N ₂ gas. When it is lower than the desired value, it is desirable to install a purifying device in the middle of the supply line. For example, when a gas source lower than a desired value is used, in FIG.
As well as inert gas supply lines 16 and 27 as atmosphere gas supply units for the front chamber 14 and the relay chamber 15.
It is desirable to install a purification device in the middle of the process.

(Second Embodiment) FIG. 5 is a schematic view showing an apparatus for manufacturing a semiconductor laser device according to a second embodiment of the present invention. Note that the same reference numerals are given to the same components as those of the semiconductor laser device manufacturing apparatus shown in FIG. 1 of the first embodiment, and description thereof will be omitted. As shown in FIG. 5, in the apparatus for manufacturing a semiconductor laser device according to the present embodiment, as in the case of the first embodiment, a lamination structure made of a semiconductor material using a cleavage device (not shown). Chamber 1 for cleaving the cavity and forming a cleavage end face of the resonator
1 is installed, a glove 13 for manually operating the cleavage device is installed, and further, at one end of the cleavage chamber 11,
A front chamber 14 is provided as a pre-stage for carrying the stacked structure made of the semiconductor material formed in the previous step into the cleavage chamber 11.

However, unlike the case of the first embodiment, the number of the first to n-th crystal growth chambers 12a, 12b, 12a, 12b, and 12c is different from that of the first embodiment. , 12n are provided, and the first to n-th crystal growth chambers 12a, 12b,.
n and a relay chamber 15a connecting the cleavage chamber 11 to each other,
, 15n are provided.

The front chamber 14, the cleavage chamber 11, the relay chambers 15a, 15b,..., 15n and the first to n-th crystal growth chambers 12a, 12b,. For example, an atmosphere gas supply unit that supplies highly purified N ₂ gas, a source gas supply line that supplies various source gases to the first to n-th crystal growth chambers 12a, 12b,. The pressure sensor and the like for sensing the fluctuation of the pressure in the cleavage chamber 11 are basically the same as those shown in FIG. 1 of the first embodiment, and their illustration and description are omitted.

The process of manufacturing a semiconductor laser device using the semiconductor laser device manufacturing apparatus of FIG. 5 is basically the same as that of the first embodiment, except that a plurality of first to n-th semiconductor laser devices are manufactured. , 12n, it is possible to perform a plurality of continuous processes that cannot be realized in the case of one crystal growth chamber.

In this case, also in this case, the cleavage chamber 11 for performing the cleavage operation,
The n-th crystal growth chambers 12a, 12b,..., 12n, the cleavage chamber 11 and the first to n-th crystal growth chambers 12a, 12b,
, The relay chambers 15a, 1 via
The atmosphere in each room of 5b, ..., 15n has an oxygen concentration of 20ppb
Hereinafter, since the water concentration is controlled to be 20 ppb or less, it is possible to realize a process that is not affected by oxidation. Therefore, the crystal growth layers formed in the first to n-th crystal growth chambers 12a, 12b,..., 12n can be high quality crystal films with few defects.

In the second embodiment, the cleavage chamber 11 and the first to n-th crystal growth chambers 12a and 12b,
, 12n and relay rooms 15a, 15
, 15n are installed separately, but a connecting path connecting these relay chambers 15a, 15b,..., 15n to each other is provided, and the atmosphere in the connecting path is set to the relay chambers 15a,
5b,..., 15n, for example, when transporting from the first crystal growth chamber 12a to the second crystal growth chamber 12b, the relay chamber does not pass through the cleavage chamber 11. It is also possible to carry via the connection path 15a, the connection path, and the relay room 15b. In this case, the transport distance is shortened, and the throughput is improved.

[0056]

As is apparent from the above description, the semiconductor laser device manufacturing apparatus according to the present invention has the following effects. That is, according to the semiconductor laser device manufacturing apparatus according to claim 1, in the manufacturing process of the semiconductor laser device which is easily affected by oxidation, after processing the semiconductor substrate, without being exposed to oxygen or moisture in the air, Since it becomes possible to continuously form an epitaxial crystal growth film on the processed surface of the semiconductor substrate, a high-quality crystal film with few defects can be obtained, and a high-quality, high-reliability semiconductor laser device can be obtained. It can contribute to realization.

According to the semiconductor laser device manufacturing apparatus of the present invention, the process from the work of cleaving the laminated structure to the work of growing the crystal on the cleaved end face is exposed to oxygen or moisture in the atmosphere. Therefore, it is possible to prevent the oxidation of the cleavage end face, and therefore, it is possible to obtain a high quality crystal film with few defects by continuous epitaxial crystal growth on the cleavage end face in the crystal growth chamber. , C
This can contribute to the realization of a semiconductor laser device having a high output and a long life in which occurrence of OD is suppressed.

According to the semiconductor laser device manufacturing apparatus of the third aspect, the processed surface exposed in the working chamber (the cleaved end face cleaved in the cleavage chamber) is prevented from being rapidly oxidized. be able to. Further, according to the semiconductor laser device manufacturing apparatus of the fourth aspect, non-automated work in a work room can be easily performed.

According to the semiconductor laser device manufacturing apparatus of the fifth aspect, since the high-purity inert gas is continuously supplied by the continuous supply type atmosphere gas supply unit, the high-purity inert gas before the epitaxial crystal growth film is formed. Exposure of the processed surface of the semiconductor substrate to atmospheric oxygen or moisture can be easily prevented. According to the semiconductor laser device manufacturing apparatus of the present invention, since the high-purity inert gas is cyclically supplied by the circulating gas supply section, the semiconductor before the epitaxial crystal growth film is formed. Since the amount of high-purity inert gas used to prevent the processed surface of the substrate from being exposed to oxygen or moisture in the atmosphere can be reduced, the cost can be reduced.

According to the apparatus for manufacturing a semiconductor laser device of the present invention, the high-purity inert gas to which the high-purity inert gas is cyclically supplied by the circulation gas supply unit is purified by the purifier. Purification enables the high-purity inert gas to be always kept in a high-quality state. Also,
According to the apparatus for manufacturing a semiconductor laser device according to claim 8,
Since it is possible to always keep the pressure in the working room constant, for example, when putting in and taking out the gloves installed in the working room, it is easy to put in and out the glove, and to stably maintain the processing operation conditions in the working room. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a semiconductor laser device manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a laminated structure made of a semiconductor material before cleavage, which is carried into the semiconductor laser device manufacturing apparatus of FIG. 1;

3 is a graph showing the results of SIMS measurements performed on the end face growth and near the layer cleavage plane of a semiconductor laser device manufactured using the semiconductor laser device manufacturing apparatus of FIG.

FIG. 4 is a graph showing a result of SIMS measurement performed on an end face growth of a semiconductor laser device manufactured for comparison and near a layer cleavage plane.

FIG. 5 is a schematic diagram showing a semiconductor laser device manufacturing apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic view showing a conventional semiconductor laser device manufacturing apparatus.

[Explanation of symbols]

Reference Signs List 1 semiconductor substrate (n-GaAs) 2 lower cladding layer (n-AlGaAs) 3 lower light confinement layer (non-doped AlGaAs) 4 active layer (InGaAs / GaAs multiple quantum well structure) 5 upper light confinement layer (non-doped AlGaAs) 6 upper part cladding layer (p-AlGaAs) 7 cap (p-GaAs) 8 protective film (Si ₃ N ₄₎ 9 upper electrode (Ti / Pt / Au) 10 lower electrode (AuGeNi / Au) 11 cleavage chamber 12 the crystal growth chamber 12a first 1 crystal growth chamber 12b second crystal growth chamber 12n n-th crystal growth chamber 13 globe 14 front chamber 15, 15a, 15b,..., 15n relay chamber 16, 27 inert gas supply lines 17a, 17b,. Valve 18 Vacuum pump 19, 29, 32 Exhaust line 20 Atmospheric gas supply unit 21 Inert gas Pressure lines 22a, 22b control valve 23 purifier 24 gas flowmeter 25 circulating blower 26 vacuum line 30 material gas supply line 33 pressure sensor

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norio Okubo 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. F-term (reference) 5F045 AA04 AB10 AB17 AC15 AC16 BB16 CA12 DA53 EB08 EE14 EN02 EN04 GH01 HA25 5F073 AA85 AA86 BA01 BA06 CA07 CB02 DA05 DA32 DA33 DA35 EA24 EA28

Claims (8)

[Claims] A work chamber for performing predetermined processing on a semiconductor substrate; a crystal growth chamber for performing epitaxial crystal growth on the semiconductor substrate having been subjected to predetermined processing in the work chamber; and a work chamber and the crystal growth chamber. An apparatus for manufacturing a semiconductor laser device, comprising: a relay chamber to be connected; and an atmosphere gas supply unit for supplying a high-purity inert gas to the work chamber, the crystal growth chamber, and the relay chamber. 2. The cleavage chamber provided with a cleavage device for cleaving a stacked structure made of a semiconductor material to form a cleavage end face of a resonator, wherein the crystal growth chamber is formed in the cleavage chamber. 2. The semiconductor laser device manufacturing apparatus according to claim 1, wherein the crystal growth chamber forms an end face growth layer by epitaxially growing a compound semiconductor on a cleaved end face of the resonator. 3. The high-purity inert gas supplied to the working chamber, the epitaxial growth chamber, and the relay chamber by the atmosphere gas supply unit has a concentration of oxygen and moisture lower than 1 ppm. Item 3. An apparatus for manufacturing a semiconductor laser device according to item 1 or 2. 4. A glove for performing work requiring human intervention is attached to the work chamber.
An apparatus for manufacturing a semiconductor laser device according to claim 1. 5. The semiconductor laser according to claim 1, wherein the atmosphere gas supply unit is a continuous supply type gas supply unit that continuously supplies high-purity inert gas from one side and exhausts the other side from the other. Device manufacturing equipment. 6. An atmosphere gas supply unit for supplying a high-purity inert gas to at least the crystal growth chamber is a circulation supply system gas supply unit for circulating and re-supplying the high-purity inert gas once supplied. An apparatus for manufacturing a semiconductor laser device according to any one of claims 1 to 4. 7. A semiconductor laser device according to claim 6, wherein a purifying device for purifying the high-purity inert gas is provided in a path for circulating and supplying the high-purity inert gas by the atmosphere gas supply unit. Manufacturing equipment. 8. A pressure sensor that senses pressure fluctuations in the working chamber, and a gas flow controller that controls a supply amount of a high-purity inert gas supplied to the working chamber based on a signal from the pressure sensor is provided. The apparatus for manufacturing a semiconductor laser device according to claim 1, wherein: