JPS61102786A - semiconductor light emitting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use Visible light-emitting diodes are widely used in panel displays, traffic lights, outdoor displays, etc. It is also being used in new fields as an eraser light source, an LED array for printers, and a light source for fiber communications. The conditions required for LEDs in the new field are:
Al1 degree 9.4 output, high speed response, etc. are required.

The present invention relates to a red LED, and more particularly, to a high-intensity, high-speed-response light-emitting conductor device that has a substrate cladding layer with an energy gap wider than the light-emitting region, eliminates absorption of radiation light, and has a thin light-emitting region.

Conventional technology The visible LED with the highest brightness and fastest response is the Ga AI Att red LED. Representative examples include Appl, Phys, Lettera, and VO.
H, Ishigu of L43゜P4O10 (1983) magazine
It is known to fabricate a GaAlAs cladding layer light-emitting region and a cladding layer on a GaAlAs substrate, as described by Ro etal.

Problems to be Solved by the Invention However, in the above-mentioned conventional example, G a A I A m
Since a crystal is used, as the emission peak wavelength becomes shorter, the influence of the indirect transition region becomes stronger and the emission efficiency deteriorates. On the other hand, since the cladding layer also uses GaAlAs crystal, the AIAsaA ratio of the cladding layer is uniquely determined.
As a result, tensile stress remains in the light emitting region.

Means for Solving the Problems The present invention provides aluminum arsenide (AlAs) with a mixed crystal ratio of 0.
．． Gallium aluminum arsenide (GaAlAs
i) Indium (In), gallium (Ga), and aluminum (Al) exhibiting the same conductivity type and lattice-matched to the GaAIAs crystal of the substrate on the base.
and a first layer of a crystal (GaAl Inp) containing phosphorus Pi and having a ratio of Ga to At of 0.3 or more, and a second layer of a crystal (GaImp) containing indium (In), gallium (Ga), and phosphorus pl. and G a A of the substrate
Indium (In) with a conductivity type different from IAs crystal,
This is a hand conductor light emitting device having a structure in which a third layer, which is a crystal containing gallium ((ja)), aluminum (Al), and phosphorus (p=2) and has a Ga to AI ratio of 0.3 or more, is sequentially laminated.

According to the present invention, an InGaAIAsP crystal is used in the cladding layer instead of the conventional GaAlAs crystal, and the light emitting region [
By employing InGap crystal, a # conductor light emitting device with low stress in the light emitting region, high reliability, and high efficiency can be realized.

EXAMPLE The present invention will be explained in detail using an InGapnGa photodiode as an example. FIG. 1 shows InGa according to the present invention.
A cross-sectional view of a p-red LED is shown. First, a method for growing a Ga AI A ts crystal used as a substrate 1 will be described. For high-purity carbon crystal growth equipment,
P-type GaAs substrate (Zn doped.

N: l×10 cm) and G as the growth solution material.
G a As polycrystalline 72Tn9 per a1p. A14
．． 6'+51 Furthermore, Zn is weighed as an impurity in 11R9, and the apparatus is prepared.

After sufficiently dissolving at a high temperature of 900C, the m liquid and the substrate are brought into contact. The crystal-grown GaAIAs) were slowly cooled to 750° C. at a cooling rate of 0.6 C/min.
The As mixed crystal ratio gradually decreases from 0.65 to 0.40. Impurity once, 3~5x10cms thickness is 20
0 to 250 p.m. Thereafter, the GaAs substrate is removed by selective etching using a mixture of ammonia and hydrogen peroxide. Using this GaAIAs crystal as a new substrate 1, an InGaAIP crystal 2 is formed using the MOCVD method. The mixed crystal ratio is 0.5, 0.35A.
10.16P, and the lattice mismatch with the substrate 1 is 0.1 inch or less. The impurity concentration is 3 x 10"cm = the film thickness is about 10 μm. Furthermore, the InGap crystal 3 of the light emitting region is formed. The film thickness is about 0.5 μm and it is a non-doped layer. The mixed crystal ratio is I no , 6G ao, s
P, and the lattice mismatch is 0.1% or less. Furthermore, an InGaAIP layer 4 of Se dope is grown with the same mixed crystal ratio as the InGaAIP crystal 2 as the first cladding layer. The film thickness is approximately 10 μm, and the impurity degree is 1 to 3×10 cm. Thereafter, a p911 electrode 5 and an n-side electrode 6 are formed using a normal vapor deposition method, and elements are separated and assembled into a predetermined comb. Although it is optimal that no strain be applied to the light emitting region, since there is a difference between the crystal growth temperature and room temperature, strain is generally applied due to the difference in expansion coefficient. By controlling the mixed crystal ratio and film thickness, the compressive stress was controlled to be 10 dyne/c#1 or less.

FIG. 2 shows the light emitting current characteristics of the red D (I) of the present example and the GaAlAs red D (II) of the conventional example.
Gap has a high light output due to its high luminous efficiency.

FIG. 3 shows a red LED (I) according to the present invention and a conventional Ga LED.
Forward current IF with AlAs red LED (If) = 5
It shows the change in luminescence output over time at 0 mAD, C.

GaAlAs LED is Hf4JILEDT
Problems in use: The survival rate after 1000 hours is 70%, but in the LED of the present invention, the stress applied to the light emitting region is controlled to compressive stress, so there is almost no change in the light emission output even after 1000 hours. do not have.

Effects of the invention By using an InGap crystal in the light emitting region instead of a GaAIAs crystal, a high-altitude LED 2 to 3 times higher than that of a conventional GaAlAs red LED was obtained. By controlling the mixed crystal ratio and film thickness, the stress applied to the light emitting region can be reduced to 10 dyne/crN.
The compression pressure can be reduced to below, and the highly reliable LED has been developed.

[Brief explanation of the drawing]

Fig. 1 is an analysis diagram of a leprosy example of the present invention, Fig. 2 is a light output-current characteristic diagram of an LED according to the present invention and a conventional LED, and Fig. 3 is a light output of an LED according to the present invention and a conventional LED. FIG. 1...GaAIAS substrate, 2---InG
aA I P cladding layer, 3... Light emitting region, 4
...InGaAIP cladding layer, 5...
p 1ull electrode, 6...N side control. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2: No. 1 TF (2η74) Figure 3: 4 (hp)

Claims (1)

[Claims] On a gallium aluminum arsenide (GaAlAs) substrate with an aluminum arsenide (AlAs) mixed crystal ratio of 0.4 or more, indium (In) and gallium (Ga) of the same conductivity type and lattice matched with the GaAlAs crystal of the substrate are deposited. )
, the first layer is a crystal containing aluminum (Al) and phosphorous p, and the ratio of Ga to Al is 0.3 or more; the second layer containing indium (In), gallium (Ga) phosphorous p; and the GaAlAs crystal. It shows a conductivity type different from that of the substrate, and contains indium (In), gallium (Ga), aluminum (
A semiconductor light emitting device having a structure in which a third layer is successively laminated with a third layer which is a crystal containing Al) and phosphorus (P) and has a ratio of Ga to Al of 0.3 or more.