JPH05343801A - Manufacturing method of multi-wavelength laser - Google Patents

Abstract

PURPOSE:To obtain a multiwavelength laser in which different oscillation wavelengths are arranged in arbitrary order by a method wherein a single- crystal substrate is irradiated with a laser beam partially and by changing its irradiation start time and a laser structure is manufactured. CONSTITUTION:A clad layer 2 and a guide layer 3 are grown on a single-crystal substrate 1; they are irradiated with a laser beam partly and by changing its irradiation time; active layers 4, 41, 42 whose photoluminescence wavelength is different from each other are manufactured. In succession, a guide layer 5 and an upper clad layer 6 are grown continuously; they are worked to be a laser array. Thereby, a multiwavelength laser wherein lasers whose oscillation wavelength is different from each other are arranged in arbitrary order can be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multi-wavelength laser in which a plurality of lasers having different oscillation wavelengths (photoluminescence wavelengths) are aligned on the same substrate.

[0002]

2. Description of the Related Art As various systems such as optoelectronics become more sophisticated and more sophisticated, higher integration is required for semiconductor elements, which are the main parts of the devices used for them.

A multi-wavelength laser is a typical example of the above components. For example, Electronics Letters (Ele
ctronics Letters Vol. 26, No. 13 (1
(1990) p. 940, when a semiconductor thin film is laminated with an active layer, molecular beam epitaxy (MBE; mol)
A technique has been developed in which the thickness of a semiconductor substrate in an electrical beam epitaxy device is intentionally changed without rotating. In the thin film formed by this thin film growth method, the thickness always changes from one side of the substrate to the other at a constant rate. Using this, multiple quantum wells (MQW;
When a Multi Quantum-Well) is manufactured and used as an active layer of a laser, its oscillation wavelength also changes from one to the other. However, it is difficult to arbitrarily change the wavelengths of the lasers arranged in a line or to change only one element.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to irradiate a semiconductor substrate with light and use a method for selectively growing or controlling the composition of a semiconductor thin film on this substrate. Alternatively, the composition is partially changed to provide a multi-wavelength laser in which lasers having different oscillation wavelengths are arranged in an arbitrary order on the same substrate.

[0005]

SUMMARY OF THE INVENTION The present invention is a method for growing a semiconductor thin film on a single crystal substrate while irradiating light on the single crystal substrate by metalorganic molecular beam epitaxy when the active layer is grown. The most main feature is that the time for starting light irradiation is changed for each irradiation region to grow.

The present invention has been made based on the following newly confirmed phenomena.

That is, InGaAs film and InGaAs
In the growth of the P film, under the growth condition that the growth rate of the film becomes constant or decreases as the substrate temperature rises, a part of the substrate surface is irradiated with light to partially increase the substrate temperature. When it is increased, the growth rate and the gallium composition in the light-irradiated portion are decreased as compared with those in the non-light-irradiated portion.

When this phenomenon is applied to the production of the quantum well structure, it becomes possible to change the oscillation wavelength of the produced laser.

FIG. 1 shows the delay of the laser light irradiation start time of the photoluminescence wavelength in the portion irradiated with the laser light during the growth of the InGaAsP film forming the well layer forming the multiple quantum well from the start of the growth of the InGaAsP film. Show time dependence. From the start of the growth of the InGaAsP film to be the well layer, as the laser light irradiation time is delayed, the photoluminescence wavelength in the irradiated portion changes to the short-wave side. Therefore, when drawing several linear patterns, if the delay of the laser light irradiation from the start of the growth of the InGaAsP film that becomes the well layer is changed for each pattern, the photoluminescence wavelength is changed for each pattern. It becomes possible. Although FIG. 1 shows the case where light irradiation is performed during growth of the quantum well layer, the same effect can be obtained by performing light irradiation during growth of the barrier layer.

As described above, when a multiple quantum well is produced, the present method can be used during the growth of the well layer or the growth of the barrier layer to obtain a laser having multiple quantum wells having partially different oscillation wavelengths. it can.

Further, as shown in FIGS. 2 to 4, by using this method during the growth of the active layer of the laser, a laser crystal having an active layer having a different oscillation wavelength (photoluminescence wavelength) depending on the location can be obtained. A laser structure can be manufactured using this crystal.

2 to 4, 1 is a substrate, 2 is a lower cladding, 3 is a guide layer, 4 is an active layer, 5 is a guide layer, 6
Is an upper cladding layer, and 7 and 8 are electrodes. Reference numerals 41 and 42 denote active layers having different photoluminescence wavelengths, which are produced by partial irradiation of laser light.

As shown in FIG. 2, a clad layer 2 and a guide layer 3 are grown on a single crystal substrate 1. After that, partial irradiation of laser light is performed on the guide layer 3 while changing the irradiation time, whereby active layers 4, 41, 42 having different photoluminescence wavelengths are produced. Subsequently, as shown in FIG. 3, the guide layer 5 and the upper cladding layer 6 are continuously grown on this. Next, as shown in FIG. 4, this is processed into a laser array. The lasing wavelength of each laser manufactured in this way is different.

As described above, by irradiating a laser on a single crystal substrate partially and at different irradiation times to produce a laser structure, lasers having different active layer structures, that is, lasers having different oscillation wavelengths are produced. It becomes possible to fabricate multi-wavelength lasers arranged in an arbitrary order.

Although the ridge type laser is shown in FIG. 2, it is possible to adopt a structure such as an embedded type according to need.

[0016]

As described above, according to the method of the present invention, a laser structure is produced by partially irradiating a laser on a single crystal substrate, whereby the structure of the active layer is different on the same substrate. A multi-wavelength laser in which lasers having different oscillation wavelengths are arranged in an arbitrary order can be manufactured.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0018]

EXAMPLES The following specific examples will be described with reference to FIGS.

An n-type InP substrate 1 having a thickness of 350 μm is formed on the n-type InP substrate 1 by using an organic metal molecular beam epitaxial device.
The P clad layer 2 is grown to a thickness of 0.5 μm, and then n
The type InGaAsP guide layer 3 was grown to a thickness of 0.1 μm. Next, InGaAs of the quantum well forming the active layer 4
P (equivalent wavelength 1.1 μm) barrier layer and InGaAsP
(Equivalent wavelength 1.4 μm) and well layers were alternately grown. At this time, during the growth of the well layer, 5 W of argon laser light (irradiation beam diameter of about 400 μmφ) was irradiated 3 seconds after the growth of the well layer was started, and 1 mm from the irradiation portion.
The remote location was illuminated after 12 seconds.

Next, the InGaAsP guide layer 5 is set to 0.1
μm and p-type InP clad layer 6 were grown to 1.5 μm respectively. A laser in which three lasers were arranged in an arbitrary order was produced using the laser irradiation part and the non-irradiation part.
Each of these three lasers has an oscillation wavelength of about 10
It was different by 0 nm.

The growth conditions for the metalorganic molecular beam epitaxial growth in this case were as follows. The raw materials used were arsine AsH ₃ , phosphine PH ₃ , trimethylindium TMIn, and triethylgallium TEGa, the ultimate vacuum was 1 × 10 ⁻⁹ Torr, and the substrate growth temperature was 510 ° C. The growth rate of multiple quantum wells is 1.3
It was μm / h.

[0022]

As described above, according to the method of the present invention, it is possible to form a multi-wavelength laser in which desired wavelengths are arranged in a desired order. Therefore, by using this manufacturing method, an optical element such as a multi-wavelength laser array, which is expected as a key device in the future, or an optical-electronic integrated circuit (OEIC; opto-electronic in circuit).
It becomes possible to form a integrated circuit.

[Brief description of drawings]

FIG. 1 InGa serving as a well layer forming a multiple quantum well
The InGaA of the laser light irradiation start time of the photoluminescence wavelength of the portion irradiated with the laser light during the growth of the AsP film.
6 is a graph showing the dependence on the delay time from the start of sP film growth.

FIG. 2 is a cross-sectional configuration diagram of a multi-wavelength laser during a manufacturing process of the laser of the present invention.

FIG. 3 is a cross-sectional configuration diagram of a multi-wavelength laser during a manufacturing process of the laser of the present invention.

FIG. 4 is a cross-sectional configuration diagram of a multi-wavelength laser after completion of fabrication of the laser of the present invention.

[Explanation of symbols]

 1 substrate 2 lower clad 3 guide layer 4 active layer 5 guide layer 6 upper clad layer 7 electrode 8 electrode 41 active layer 42 active layer

Claims (1)

[Claims] 1. A method of manufacturing a multi-wavelength laser in which a multi-wavelength laser structure is grown on the same single crystal substrate by an organometallic molecular beam epitaxial method, wherein a part of the single crystal substrate is irradiated with laser light. However, when the active layer made of a III-V semiconductor thin film is grown on the substrate, the laser light is irradiated onto a plurality of lines, and at this time, irradiation time is started for each irradiation region. A method of manufacturing a multi-wavelength laser, characterized in that a part of a laser composed of a plurality of lasers is formed by changing at least a part of the irradiated area.