JPS60120583A - Semiconductor light emitting device - Google Patents

Abstract

PURPOSE:To eliminate a shortcircuit caused by the disconnection of a buried layer by forming a buried layer and an insulating film on an active layer mode of a mesa-shaped lead, tin and tellurium formed on a semiconductor substrate made of at least lead or tellurium, and forming electrodes contacted with the buried layer through a hole formed in the insulating film. CONSTITUTION:A P type Pb.Te.Se enclosure layer 12 is grown, for example, by a liquid phase epitaxial growing method on a Pb.Te substrate 11. Then, a Pb. Sn.Te active layer 13 is grown by similarly a liquid phase eqitaxial growing method. Then, the layers 13, 12 are patterned to form a mesa-shape. Further, an N type Pb.Sn.Te buried layer 14 is formed by a liquid phase epitaxial growing method. Then, an insulating film 15 is grown, the film 15 is then patterned to form a hole 15A to expose part of the surface of the layer 14. Then, electrodes 16 made of gold is similarly formed by depositing and electrodes 17 made of gold are also formed on the back surface of the substrate 11. Then, individual semiconductor lasers are separated to complete it.

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to lead, tin, and chil which oscillate at wavelengths in the far infrared region.
The present invention relates to improvements in Lt(Pb-3n-Te)/P'b-Te based semiconductor light emitting devices.

Conventional technology and problems In general, compound semiconductors made of Pb-3n-Te have excellent photoelectric conversion functions in the far-infrared region, so they are used in many applications such as imaging elements of infrared cameras, gas detection elements, and various other sensors. Developments have been made, and semiconductor lasers are one of them.

Incidentally, a semiconductor light emitting device called a buried semiconductor laser has been known to have a structure suitable for confining light or confining current.

It goes without saying that if the semiconductor laser using Pb-5n-Te is made into a buried type, the same effects as those of a normal buried type semiconductor laser can be expected.

However, there are many difficulties in manufacturing a buried semiconductor laser using Pb-3n-Te.

One of them will be explained with reference to FIGS. 1 and 2. 1 and 2 are cutaway front views of essential parts of the semiconductor laser at key points in the process.

In Figure 1, there is a mesa-like shape on the P b -T'e substrate 1]
b・5n-Te active layer 2 is formed, and pb・S
This shows a state in which an n-selenium (Se) buried layer 3 is formed.

As can be seen from the figure, when the buried layer 3 is grown, it is not formed over the entire surface of the substrate 1, but is cut off in places, and the surface of the substrate 1, which is the underlying layer, is exposed.

Therefore, as shown in FIG. 2, when the electrode 4 is formed, a part of it comes into direct contact with the substrate 1, so that normal operation cannot be performed.

In this type of compound semiconductor, since the specific gravity of each element differs greatly, it is difficult to obtain a large single crystal even in normal cases. Single crystals are considered difficult to grow.

OBJECTS OF THE INVENTION The present invention attempts to eliminate the short circuit caused by the breakage of the buried layer with a structure obtainable with current technology.

Structure of the Invention The semiconductor light emitting device of the present invention includes at least a semiconductor substrate made of lead and tellurium, a mesa-shaped active layer made of lead, tin and tellurium formed on the semiconductor substrate, a buried layer formed thereon, Since the structure includes an insulating film formed thereon and an electrode that contacts the buried layer through an opening formed in the insulating film, even if a break occurs in the buried layer, the Since the cut is covered with an insulating film, there is no risk of a short circuit occurring even if an electrode is formed.

Embodiment of the Invention FIGS. 3 to 8 are a cutaway front view and a cutaway oblique view of the main part of a semiconductor light emitting device at key points in the process for explaining the case of manufacturing an embodiment of the present invention. Figures only), and will be described below with reference to these figures.

Refer to FIG. 3 ■ A p-type Pb-Te-3e confinement layer 12 is formed on a Pb-Te substrate 11 by applying, for example, liquid phase epitaxial growth.
is grown to a thickness of, for example, about 10 [μm].

■ By applying the same liquid phase epitaxial growth method, Pb-
The 3n-Te active layer 13 is grown to a thickness of, for example, about 1 μm.

See FIGS. 4 and 5. (2) For example, the active layer 13 and the confinement layer 12 are patterned to form a mesa-shaped portion by applying a normal photo-phosphorography technique.

Although Fig. 4 shows one element of a semiconductor laser, in reality, as shown in Fig. 5, mesa-shaped portions for multiple screens are formed on one wafer, and are later separated individually. Needless to say, this is something that can be done.

See Figure 6 ■ Furthermore, by applying liquid phase growth epitaxial growth method, rl
A pb-5n-Te buried layer 14 is formed.

In this case, the buried layer 14 is formed to be thick around the mesa-shaped part and thin in other parts, but this is due to the crystal growth rate of the buried layer around the mesa-shaped part due to the surface orientation. Although it is fast.

Refer to FIG. 7. For example, by applying an anodic oxidation method, the insulating film 15 is grown to a thickness of, for example, about 1000 (people).

(2) For example, by patterning the insulating film 15 using a normal photolithography technique, an opening 15A is formed and a part of the surface of the buried layer 14 is exposed.

See Figure 8 ■ Electrode 1 made of gold (Au), for example by applying the vapor deposition method.
6 to a thickness of, for example, about 1000 (people).

(2) Similarly, an electrode 17 made of, for example, gold is formed on the back surface of the substrate 11 to a thickness of, for example, about 100 mm.

■ After this, it is separated into individual semiconductor lasers and completed.

As is clear from the foregoing, even if a break occurs in the buried layer 14, the break is covered with the insulating film 15, so even if the electrode work 6 is formed, the electrode 16 will not touch the substrate 11.
There is no possibility of contacting directly.

Effects of the Invention In the semiconductor light emitting device of the present invention, at least a semiconductor substrate made of lead and tellurium, a mesa-shaped active layer made of lead, tin and tellurium formed on the semiconductor substrate, and a Since the structure includes a buried layer, an insulating film formed on the buried layer, and an electrode that contacts the buried layer through an opening formed in the insulating film, the buried layer is formed on the semiconductor substrate. Even if it is formed without spreading over the entire surface, since there is an insulating film on top of it, there is no possibility that the electrode will come into direct contact with the semiconductor substrate at any location other than the desired area, thus preventing short circuit accidents. This does not occur, and the manufacturing yield is significantly improved.

[Brief explanation of drawings]

1 and 2 are cutaway front views of essential parts of a semiconductor light emitting device at key points in the process for explaining the case of manufacturing a conventional example;
3 to 8 are a cut-away front view and a cut-away oblique view (FIG. 5 only) of the main parts of a semiconductor light emitting device at key points in the process for explaining the case of manufacturing an embodiment of the present invention. be. In the figure, 11 is a Pb-Te1 plate, 12 is a p-type Pb-
Te-3e confinement layer, 13 is a pb-sn-Te active layer, 14 is an n-type Pb-3n·Fe buried layer, 15 is an insulating film, 1.5A is an opening, 1G and 17 are electrodes. Patent application Person Fujitsu Ltd. Representative Patent Attorney Akira Aitani Representative Patent Attorney Hiroshi Watanabe - Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] a semiconductor substrate made of at least lead and tellurium; a mesa-shaped active layer made of lead, tin and tellurium formed on the semiconductor substrate; a buried layer formed thereon; an insulating film formed thereon; A semiconductor light emitting device comprising an electrode that contacts the buried layer through an opening formed in a film.