JPH02260681A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To produce layer rays at different wavelengths by a method wherein the surface parts of a board under a first and a second laser oscillation layer are provided deviating from each other in level. CONSTITUTION:A semiconductor laser device 1 is formed in such a structure that a first laser oscillating layer 3 and a second laser oscillating layer 4 both of AlGaInP are provided adjacent to each other on a first surface part 2a and a second surface part 2b of a single GaAs board 2 respectively. The GaAs board 2 is of an N-type, and the first surface part 2a has a (100) plane and the second surface part 2b has a plane inclined by an angle of 5 degrees in a <011> orientation to the (100) plane. By this setup, laser oscillating layers different from each other in oscillation wavelength can be obtained through a single laser oscillation layer forming process.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a semiconductor laser device.

(B) Prior Art A semiconductor laser device that can oscillate a plurality of beams and each beam has a different wavelength is useful as a light source for writing and erasing information in, for example, a phase change type optical disk device.

Appj, Phys, Lett, etc. as prior art
Voj, 43°No, 10.15 November
1983 (pages 903 to 905), a ridge-shaped portion and a terrace-shaped portion are provided on the surface of a single GaAs substrate, and a laser oscillation layer is grown on each portion to form each laser. A laser device that can generate laser beams of different wavelengths from an oscillation layer is disclosed.

However, with such a structure, the surfaces of the substrates must be processed into different shapes, making the manufacturing process complicated.

(c) Problems to be Solved by the Invention The present invention provides a semiconductor laser device that can generate a plurality of beams with different wavelengths and is easy to manufacture.

(d) Means for Solving the Problems The semiconductor laser device of the present invention has the following features:
A structure in which at least first and second laser oscillation layers are grown adjacent to each other, wherein surface portions of the substrate below the first and second laser oscillation layers are not in the same plane. It is characterized by

(e) Effect For example, AIGaIn is deposited on the (100) plane of a GaAs substrate.
When a P-based laser oscillation layer is grown and formed, similar AJ! In the case where a Ga I nP-based laser oscillation layer is grown, the oscillation wavelength in the former oscillation layer is
The latter one shifts toward shorter wavelengths. The relationship between the tilt angle in the above direction and the emission wavelength is shown in FIG. 5 as a result of 7 otoluminescence measurements. Note that this is a measurement at room temperature of a GalnP layer grown on the above substrate by MOCVD at a temperature of 710°C.

Therefore, by providing portions that are not on the same plane in a single semiconductor substrate in this way, it is possible to obtain laser oscillation layers with different oscillation wavelengths in - times of the laser oscillation layer formation process. .

Also, the oscillation layer is AJ! By using a Ga I nP system, each oscillation wavelength can be set in the visible light range. In this respect, the structure of the prior art described above has a long wavelength longer than 780 nm.

(F) Embodiment FIG. 1 shows a semiconductor laser device (1) as an embodiment of the present invention. This device consists of a single GaAs substrate (2
), a first laser oscillation layer (3) and a second laser oscillation layer (4) made of an AJtGa I nP system are placed adjacent to each other on the first surface portion (2a) and the second surface portion (2b), respectively. It was formed.

The GaAs substrate (2) is of n-type, and the first surface portion (2a
) is the (100) plane, and the second surface portion (2b) is the (10
0) has a surface tilted 5 degrees in the <011> direction.

The first and second laser oscillation layers (3) and (4) are both wavelength-formed on the substrate (2) via the n-side buffer layer (5), and are arranged in order from the bottom to the n-side cladding layer (6). ), active layer (7
), and a p-side rad layer (8). Furthermore, p
The upper surface of the side rad layer (8) has a mesa shape for current concentration, and a p-side buffer layer (9) and a cap layer (10) are laminated thereon. The composition of each of these layers is shown in the table below. The cavity length of each laser oscillation layer is 300
It is μm.

The exposed surface of the p-side rad layer (8) and the p-side buffer layer (
9) and the side surfaces of the cap layer (1o) are A l *Os
An insulating film (11) consisting of
) on the exposed surface of the p-side electrode (12
) is coated. Further, an n-side electrode (13) made of a Cr-5n-Au alloy is adhered to the back surface of the substrate (2).

The oscillation spectra of the first and second laser oscillation layers (3) and (4) are shown in Figure 2 A and B, and the current-light output characteristics are shown in Figure 3 A.
and B, respectively. As can be seen from these, the first laser oscillation layer (3) has an oscillation wavelength of 695 nm and an oscillation threshold of about 70 mA, and the second laser oscillation layer (4) has an oscillation wavelength of 660 nm and an oscillation threshold of about 70 mA. Has a threshold.

FIG. 4 shows the manufacturing process of the device (1) of this embodiment.

In the step shown in FIG. 4A, a G5As substrate (2) is prepared.

In this substrate, a part of the (100) plane is tilted 5 degrees in the <011> direction to form the second surface part (2b), and the remaining (100)
) is the first surface portion (2a).

In the step shown in FIG. 4B, layers from the n-side buffer layer (5) to the cap layer (10) are successively grown on the substrate (2) using the MOCVD method.

In the step shown in FIG. 4C, a mesa etch that reaches the p-type cladding layer (8) is provided above the first and second surface portions (2a) and (2b), and an insulating film (11) is deposited on the etched surface. Furthermore, an n-side electrode (12) is provided on the exposed cap layer (10).

In the fourth drawing process, using an aqua regia-based etching solution,
A separation groove (14) reaching from the surface of the n-side electrode (12) to the n-side buffer layer (5) is provided at the boundary position between the first surface portion (2a) and the second surface portion (2b), and the first laser oscillation is performed. layer(
3) and the second laser oscillation layer (4) are formed separately. Next, after forming the n-side electrode (13), the device (1) is completed by cutting it so that the resonator length becomes 3-00 μm.

In the above device, the first and second surface portions (2a) (2b
), it is also possible to create a surface with a different angle of inclination to make it possible to oscillate three or more beams of different wavelengths.

(G) Effects of the Invention According to the present invention, it is possible to obtain a semiconductor laser device that can generate a plurality of beams with different wavelengths by simply shifting the surface portions of the substrate from within the same plane, and It is also possible to set the wavelength of the light in the visible light range.

[Brief explanation of drawings]

The figures illustrate the present invention, with Figure 1 being a side view of the device, Figure 2 being a side view of the device;
Figure 3 is a characteristic curve diagram, Figures 4A to 4 are side views of each process for manufacturing the above device, and Figure 5 is a curve diagram showing the relationship between the tilt angle of the substrate surface and the emission wavelength. .

Claims (1)

[Claims] (1) A structure in which at least first and second laser oscillation layers are grown adjacently on a single semiconductor substrate,
A semiconductor laser device characterized in that surface portions of the substrate under the first and second laser oscillation layers are not in the same plane.