JP3019174B2 - Manufacturing method of multi-wavelength laser - Google Patents

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 arranged on the same substrate.

[0002]

2. Description of the Related Art With the advancement and sophistication of various systems such as optoelectronics, high integration is required for semiconductor elements, which are main components of devices used for these systems.

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

[0004]

An object of the present invention is to provide a method for selectively growing or controlling the composition of a semiconductor thin film on a semiconductor substrate while irradiating the light on the semiconductor substrate. Another object of the present invention is to provide a multi-wavelength laser in which lasers having different oscillation wavelengths are arranged in an arbitrary order on the same substrate by partially changing the composition.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method of growing a semiconductor thin film on a single crystal substrate while irradiating the substrate with light by the metalorganic molecular beam epitaxial method. The most important feature is that the growth is performed by changing the time at which light irradiation is started for each irradiation region.

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

That is, an InGaAs film or InGaAs
In the growth of the P film, a part of the substrate surface is irradiated with light under a growth condition in which the growth rate of the film becomes constant or decreases as the substrate temperature increases, and the substrate temperature is partially reduced. When it is increased, the growth rate and the gallium composition in the light-irradiated part decrease as compared with the non-light-irradiated part.

If this phenomenon is applied to the fabrication of a quantum well structure, the oscillation wavelength of the fabricated laser can be changed.

FIG. 1 shows the delay of the laser light irradiation start time from the start of the growth of the InGaAsP film in the portion irradiated with the laser light during the growth of the InGaAsP film serving as the well layer forming the multiple quantum well. Shows time dependency. As the time of laser light irradiation is delayed from the start of the growth of the InGaAsP film serving as a well layer, the photoluminescence wavelength in the irradiated portion changes to the shorter wavelength side. Therefore, when writing several linear patterns, if the time delay of laser light irradiation is changed for each pattern from the start of growth of the InGaAsP film serving as a well layer, the photoluminescence wavelength changes for each pattern. It is possible to do. FIG. 1 shows the case where light irradiation is performed during the growth of the quantum well layer. However, the same effect can be obtained by performing light irradiation during the growth of the barrier layer.

As described above, when a multi-quantum well is manufactured, by using this method at the time of growing a well layer or a barrier layer, it is possible to obtain a laser having a multi-quantum well having a partially different oscillation wavelength. it can.

As shown in FIGS. 2 to 4, by using this method at the time of growing an active layer of a 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 formed by partial irradiation of laser light and having different photoluminescence wavelengths.

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

As described above, by irradiating a single crystal substrate with a laser beam while partially changing the irradiation time to form a laser structure, a laser having a different active layer structure, that is, a laser having a different oscillation wavelength can be obtained. Multi-wavelength lasers arranged in an arbitrary order can be manufactured.

Although a ridge type laser is shown in FIG. 2, it is possible to use a buried type laser or the like as required.

[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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following specific embodiments will be described with reference to FIGS.

An n-type InP substrate 1 having a thickness of 350 μm is placed on an n-type InP substrate 1 using an organometallic molecular beam epitaxy apparatus.
A P-cladding layer 2 is grown to a thickness of 0.5 μm, followed by n
The type InGaAsP guide layer 3 was grown to a thickness of 0.1 μm. Next, InGaAs of the quantum well constituting the active layer 4 is used.
P (equivalent wavelength 1.1 μm) barrier layer and InGaAsP
(Equivalent wavelength: 1.4 μm) and well layers were alternately grown. At this time, a 5 W argon laser beam (irradiation beam diameter: about 400 μmφ) is irradiated 3 seconds after the growth of the well layer is started at the time of growth of the well layer, and 1 mm from the irradiated portion.
The remote location was irradiated after 12 seconds.

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

In this case, the growth conditions by the metalorganic molecular beam epitaxial growth 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 the multiple quantum well is 1.3
μm / h.

[0022]

As described above, according to the method of the present invention, a multi-wavelength laser having desired wavelengths arranged in a desired order can be formed. 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 opto-electronic integrated circuit (OEIC).
The formation of an integrated circuit is possible.

[Brief description of the drawings]

FIG. 1 shows InGa serving as a well layer forming a multiple quantum well.
The photoluminescence wavelength of the portion irradiated with the laser beam during the growth of the AsP film is the InGaAs at the laser beam irradiation start time.
6 is a graph showing dependence on a 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 laser manufacturing process of the present invention.

FIG. 4 is a cross-sectional configuration diagram of a multi-wavelength laser after a laser of the present invention has been manufactured.

[Explanation of symbols]

 DESCRIPTION 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

Continuation of the front page (56) References JP-A-64-27285 (JP, A) JP-A-2-32584 (JP, A) JP-A-62-227089 (JP, A) JP-A-1-300516 (JP) , A) JP-A-4-263418 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01S 5/00

Claims (1)

(57) [Claims] 1. A multi-wavelength laser manufacturing method for growing a multi-wavelength laser structure on the same single crystal substrate by metalorganic molecular beam epitaxy, wherein a part of the single crystal substrate is irradiated with laser light. While growing an active layer made of a group III-V semiconductor thin film on the substrate, the laser light is irradiated onto a plurality of lines, and at this time, the time for starting irradiation for each irradiated region is A method of manufacturing a multi-wavelength laser, wherein a part of a plurality of lasers is formed by using at least a part of the irradiated region while changing the irradiation area.