JPS5834957B2 - Manufacturing method of semiconductor laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor laser device.

FIG. 1 shows a perspective view of an oxide stripe laser, which is a typical example of a conventional semiconductor laser device.

Such a conventional laser device has a GaAlAs active region 2.
The (110) plane, which is a cleavage plane, was used as a resonance plane, and the oscillation light was extracted in a direction parallel to the growth plane, that is, in the Z direction in FIG.

Therefore, when actually mounting it on the stem, it must be mounted parallel to the direction X in which you want to extract the oscillation light, as shown in Figure 2. With this structure, extremely high thermal purity is required for positioning when mounting it on mount 1. Ta.

Furthermore, in conventional semiconductor laser devices, since oscillation light is emitted from both resonant surfaces, in conventional laser devices, the oscillation light from one side is discarded, resulting in low power efficiency.

The present invention relates to a method for manufacturing a semiconductor device that can extract oscillated light from the surface by simply mounting it like a normal light emitting diode by creating a structure in which the direction in which oscillated light is extracted is perpendicular to the bonding surface. In particular, the present invention provides a method for manufacturing a semiconductor laser device that can form a reflective layer near the oscillation part of the semiconductor laser in a simple process in order to extract oscillation light from the upper side of the substrate.

The present invention will be explained below based on examples together with the drawings.

3A to 3E are manufacturing process cross-sectional views for explaining a method of manufacturing a semiconductor laser device according to an embodiment of the present invention, and FIGS. 4A to 4B are a plan view and a side view of the same device.

First, as a substrate, the carrier concentration of Te doped is 2×10
Using (1,00)-plane GaAs 5 of 18CTL-3, n-type G was deposited on this substrate 5 by a normal liquid phase epitaxial method.
a 0.7 All! 0.3 As ], p-type GaAs 2 as active layer, P-type Ga 0.7AlO,
3A s 3 and p+ type GaAs 4 y are sequentially grown (FIG. 4a).

Next, the S t 02 film 6 is deposited on this growth wafer at a film thickness of 5000.
250mm long using photo-etching technology
The S t 02 film 6 with a μm width of 30 μm is left, and the two planes that will become the resonance planes are (100) planes (FIG. 3(b)).

Next, concentrated sulfuric acid (95%): hydrogen peroxide (30%): water is 1 part
: The part to which the SiO2 film 6 is not attached is etched at 30°C for 30 seconds using an etching solution with a volume ratio of 10:1 to remove at least p-type GaAs and n-type Ga1-x.
Etch to the AlxAsl boundary.

When the (100) plane is exposed using this etching solution, it is possible to perform etching perpendicular to the substrate 5 and to have a smooth mirror surface.

Therefore, a resonant surface can be formed by etching.

After that, a SiO2 film 6 is attached to the entire surface, and only the stripe surface of the convex part and the resonance surface are etched using photoetching technology.
02 film 6 is left (see figure c)c. Then this Si02 film 6
Using this as a mask, high-resistance GaAs1-xP27, which is to become a reflective growth layer, is placed on the part removed by mesa etching.
is formed by epitaxial growth (d in the same figure).

This high resistance region 7 was buried and grown by a thermal decomposition method using trimethyl gallium aa (CH3)s, arsine AsH3, and phosphine PH3 using a vapor phase epitaxial method.

This growth layer 7 becomes a high resistance layer of about 104.2 when grown at 600°C.

゛Since the SiO2 film 6 is used as a mask, selective growth is possible, and by coating the resonant surface with the SiO2 film 6, the end face of the high-resistance layer 7 is not perpendicular but has an angle θ between it and the resonant surface as shown in the figure d. is formed and becomes a light reflecting surface.

This means that the reflective growth layer has been formed.

When the growth temperature was 600 to 800°C, θ was 45°.

This is considered to be because GaAsP tends to grow in the <110> direction in this temperature range.

Next, the SiO2 film 6 is removed by etching, and then ohmic electrode metals 8 and 9 are deposited on both the back surface of the substrate 1 and the surface of the p-type GaAs 4.

(Figure e). Through the above steps, the device is completed.

In the semiconductor laser device manufactured as described above, as shown in FIGS. 4a and 4b, oscillation light from the resonant surface of the active layer 2 is generated at an angle of 45° between the resonant surface and the end surface of the high-resistance layer 7. The light is reflected by the light and taken out to the surface side of the growth layer (Y direction in FIG. 3).

In this embodiment, the case where the angle θ is 45° has been described, but in general, θ may be o'<θ<90° of the Ga AS 1-Z Pz layer 7 grown on the side surface.

In the semiconductor laser device obtained by the manufacturing method of the present invention, the oscillation light from the resonant surface of the active region is reflected by the reflective surface of the reflective growth layer, so the oscillation light can be extracted to the growth surface side and the stem When mounting on a light emitting device, it can be mounted using the same mounting method as a normal light emitting element, without considering the direction of the resonant plane as in the conventional case, that is, without requiring high heat greening.

The method for manufacturing a semiconductor laser device according to the present invention is to form a multilayer film including an active layer that emits light on the (100) plane of a semiconductor substrate, and then to etch the multilayer film, leaving a part of the multilayer film. GaA is added to the part removed by etching.
The feature is that a laser beam reflective layer is formed by vapor phase growth of s1-xPx.

According to the semiconductor laser manufacturing method of the present invention,
Ga A sl -x P x that becomes the reflective layer is <110
> direction, the reflective surface facing the active layer is inclined with respect to the (100) plane of the semiconductor substrate, making etching work etc. to form the reflective surface of the reflective layer completely unnecessary. It streamlines the process and has high industrial utility value.

[Brief explanation of drawings]

Fig. 1 is a structural perspective view of a conventional oxide stripe type laser, Fig. 2 is a structural diagram of a conventional laser element mounted on a stem, and Fig. 3 a''-e are semiconductor laser devices according to an embodiment of the present invention. 4A and 4B are a plan view and a cross-sectional view of a semiconductor laser device obtained by the same method. 1... n-type Ga O, 7A10 .3 As12
""GaAs (active region), 3... p-type Ga
0.7klO, 3As. 4...p 10-type GaAs, 5...n+ type GaA, ss 6...S A02 film, 7...
...High resistance GaAsP (growth layer for reflection), 8.9...
····electrode.

Claims (1)

[Claims] 1. A step of forming a multilayer film including an active layer for causing semiconductor laser oscillation on the (ioo) plane of a semiconductor substrate, a step of selectively forming an SiO□ film on the surface of the uppermost layer of the multilayer film, and etching the multilayer film using the 5102 film as a mask to remove at least the active layer;
SiO is deposited on the side surface of the multilayer film left after the etching.
2, forming a layer that reflects the laser beam emitted from the active layer by vapor-growing GaAs t-xPx on the portion removed by the etching, and forming a layer on the surface and side surfaces of the multilayer film. 1. A method for manufacturing a semiconductor laser device, comprising removing a SiO2 film.