JPS59141282A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To obtain a laser, characteristics thereof are excellent and reliability thereto is superior, by suppressing a surface morphology with a terraced stepped difference by inclining a main surface only by a specific angle while using a waveguide direction as an axis, growing a thin uniform active layer and preventing the displacement of the direction of emitting beams by controlling the direction of inclination. CONSTITUTION:A main surface is inclined at an angle of 0.2-5 deg. while using the waveguide direction as an axis. For example, a face orientation of a substrate consisting of GaAs is inclined at 1 deg. from a 100 face. Since a thin uniform active layer 13 can be acquired by inclining the substrate, currents injected to the active layer 13 are equalized, and beams emitted by injection currents do not scatter and are emitted uniformly. Since the substrate 11 is inclined in the direction that is turned while using emitting beams as an axis, the direction of emitting beams is the same as conventional type devices through the substrate 11 is inclined, and no trouble is generated even when a laser chip is mounted to a package.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor laser device, and is intended to realize a semiconductor laser device having an active layer having a thin and uniform thickness.

Figure 1 shows a semiconductor with a normal electrode stripe structure.
1 is a substrate, 2 is a cladding layer, 3 is an active layer, and 4 is a contact layer. Further, 5 is a stripe electrode, and 6 is a substrate side electrode.

In a conventional semiconductor laser, the substrate 1 is made of GaAs (1
The above-mentioned layers 2 to 4 were grown using a crystal growth technique on the 00) plane, and the (o hl) plane perpendicular to the waveguide direction was used as the resonance plane.

That is, a cladding layer 2.
After the active layer 3 and the like are grown in a liquid phase, the arms are opened parallel to the (011) plane. In Figure 1, the (011) plane and (0
11) The surface is used as a resonance surface. Therefore, the elements generated in the active layer 3 due to current injection form a pair of opposing (0
11) and (o jl ) undergoes optical amplification while reciprocating between the planes, and when the amplification factor exceeds a certain threshold, (alt
) surface as an external laser source.

The same applies to the case where the (011) plane and the (oir) plane are used as resonant planes; in this case, the laser source is emitted to the outside from the (011) plane.

Conventional semiconductor lasers use (10
Although we use a substrate 1 with as little deviation from the surface orientation as possible from the 0) plane, it is impossible to obtain a substrate with absolutely no deviation from the surface orientation. When a cladding layer 2, active layer 3, etc. are grown on top of layer 1 by liquid phase growth, a surface morphology such as terraces appears on the surface of the grown layer.Then, active layer 3, which is thin, has a thickness as shown in FIG. becomes non-uniform, and the impurity distribution and A1 composition distribution also become non-uniform, which has the drawback of deteriorating the characteristics and reliability of the laser.

This invention was made in order to eliminate the above-mentioned drawbacks, and the main surface has an angle of 0.2° to 5° (10
0) Providing a semiconductor laser that suppresses surface morphology with terrace-like steps by tilting from the surface, grows a thin and uniform active layer, and prevents the direction of emitted light from shifting by controlling the tilting direction. It is intended to.

A specific embodiment of the present invention will be described below with reference to FIG.

In FIG. 3, reference numeral 11 denotes a substrate made of GaAa, and in order to grow the active layer thinly and uniformly, the surface orientation of the substrate 11 is (
100) is tilted 1° from the plane. However, when a semiconductor laser is manufactured, the tilting direction is such that the angle between the main surface and the resonant surface does not deviate from 90 degrees, and the direction is such that the emitted light is rotated as an axis.

12 to 14 are layers obtained by liquid phase epitaxial growth, and 12 is AlxGap, As (X'; 0.4
5) cladding layer, 13 is Atz Ga+-1Aa
(x heo, ls) is an active layer, and 14 is a GaAs contact layer.

15 is a stripe electrode, and 16 is a substrate side electrode.

The operating principle is the same as the conventional one; the light generated in the active layer 13 is subjected to optical amplification while reciprocating between a pair of opposing (oli) and (oTx) surfaces, and the amplification factor exceeds a certain threshold. At this point, the light is emitted from the (Olj) plane as a laser source. By the way, in this invention, a thin and uniform active layer 13 can be obtained by tilting the substrate, so that the current injected into the active layer 13 becomes uniform, and the light emitted by the injected current is uniformly emitted without scattering. Furthermore, since the direction in which the substrate 11 is tilted is the direction in which the emitted light is rotated around the axis, the direction of the emitted light remains the same as in the conventional type even when the substrate 11 is tilted, and there is no problem when mounting a laser chip in a package. It doesn't happen.

The semiconductor laser with the electrode stripe structure shown in FIG. 3 has been described above, but the internal stripe laser, TJ
S (Tranaverae Junction 5t
It is also possible to apply the present invention to other semiconductor laser structures such as a multilayer (ripe) laser, and it is possible to obtain a semiconductor laser having a thin and uniform active layer.

FIG. 4 shows an embodiment applied to an internal stripe laser, and FIG. 5 shows an embodiment applied to a KTJS laser.

In these figures, numerals 11 to 14 indicate the same parts as in FIG. 3, 11 is an electrode, 18 is a current 1222 layer, 19 is a P+ part by Zn diffusion, and 20 is a P part by diffusion drive.

In the above two embodiments, the plane orientation of the substrate 11 is tilted by 10 degrees from the (100) plane in order to grow the active layer 13 thinly and uniformly.
Even when the angle is set to .degree., the same effect as explained in FIG. 3 can be obtained.

As explained above, according to the present invention, the plane orientation of the main surface of the substrate crystal is slightly tilted in a specific direction from the main surface, so the active layer can be made thin and uniform without tilting the emission direction of the laser source. This makes it possible to manufacture semiconductor lasers with excellent characteristics and reliability.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the structure of an example of a conventional semiconductor laser, Fig. 2 is a cross-sectional view showing the non-uniformity of the growth layer thickness, which has been a problem in conventional semiconductor lasers, and Fig. 3 is a structure according to the present invention. A perspective view of the structure of one embodiment, and FIGS. 4 and 5 show cross-sectional views of the structure when the present invention is applied to other semiconductor laser structures. In the figure, 11 is a substrate made of GaAs, 12 is a cladding layer, 13 is an active layer, 14 is a contact layer, 15 is a stripe electrode, and 16 is a substrate side electrode. Agent Shin Kuzuno - (1 other person) Figure 1 Figure 3 Figure 4 Figure 5 Procedural amendment (voluntary) 1. Indication of case: Japanese Patent Application No. 58-18593 2, Title of invention: Semiconductor laser device 3, Relationship with the person making the amendment: Address of patent applicant: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Denki Co., Ltd. Representative: Hitoshi Katayama 4, Agent Address: 2-2-3-5 Marunouchi, Chiyoda-ku, Tokyo
, Detailed Description of the Invention column of the specification subject to amendment and Drawing 6, Contents of the amendment (1) Page 2 of the specification, line 13 (7) r(011)J, r
<011) Corrected as J. (2) Amend Figure 3 of the drawing as shown in the attached sheet. that's all

Claims (4)

[Claims] (1) In a semiconductor laser in which a pair of opposing surfaces are used as resonant surfaces and the waveguide direction is the direction of 10,000 of the pair of surfaces, the principal surface is 0.2° to 0.2° with respect to the waveguide direction as an axis. A semiconductor laser device characterized by being tilted by 5 degrees. (2) The semiconductor laser device according to claim (1), wherein the main surface is a (100) plane. (3) The semiconductor laser device according to claim (1), wherein the main surface is a (001) plane. (4) The semiconductor laser device according to claim (1), wherein the main surface is a (010) plane.