JP2001028456A - Semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide semiconductor light emitting device which can be accurately fabricated at a low cost. SOLUTION: A semiconductor light emitting device 1 is equipped with semiconductor layers 3, 5, and 6 which includes an active layer 4 formed on a substrate 2, where a Fresnel lens 5A formed by processing a part of the upper semiconductor layers 5 and 6 which are out of the semiconductor layers 3, 5, and 6 and formed the light emitting region 4 is provided in the direction of the outgoing light projected from the light emitting region 4, and the outgoing light is made to be focused by the Fresnel 5A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor light emitting device such as a light emitting diode and a semiconductor laser device used as a light source for optical communication and optical measurement.

[0002]

2. Description of the Related Art When a semiconductor light emitting device is used as a light source for optical communication and optical measurement, it is necessary to efficiently output light from the semiconductor light emitting device to an optical fiber. For this purpose, Japanese Patent Publication No. 6-34410 discloses that a spherical lens or a hemispherical lens is fixed to an LED substrate side of a light emitting area for emitting a laser beam with an adhesive, and light emitted from the light emitting area is transmitted to the spherical lens. Alternatively, it is disclosed that the light is converged by the hemispherical lens.

[0003]

However, the necessity of a spherical lens or a hemispherical lens for converging the light from the light emitting region increases the cost, or makes it necessary to align these lenses with the light emitting region. There was a problem in manufacturing that it could not be performed with high accuracy.

The present invention has been made in order to solve the above problems, and has as its object to provide a semiconductor light emitting device which can be manufactured accurately at low cost.

[0005]

According to the present invention, there is provided a semiconductor light emitting device having a plurality of semiconductor layers including a light emitting region formed on a substrate, wherein the semiconductor light emitting device is provided in a direction of light emitted from the light emitting region, The semiconductor layer includes a Fresnel lens part obtained by processing a part of an upper semiconductor layer formed above the light emitting region, and the emitted light is converged by the Fresnel lens part. Provided is a semiconductor light emitting device.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the semiconductor light emitting device of the present invention will be described with reference to FIGS. FIG.
1 shows an embodiment of a semiconductor light emitting device of the present invention, in which (A) is a sectional view and (B) is a plan view. FIG. 2 is a diagram illustrating a method for manufacturing an embodiment of the semiconductor light emitting device of the present invention.

First, the configuration of the semiconductor light emitting device 1 of the present invention will be described with reference to FIG. As shown in FIG. 1, a semiconductor light emitting device 1 includes an n-type Al _0.5 Ga _0.5 As clad layer 3 formed on an n-type GaAs substrate 2,
The p-type Al _0.5 Ga _0.5 As clad layer 5 includes a _0.13 Ga _0.87 As active layer 4 and a p-type Al _0.5 Ga _0.5 As clad layer 5. Fresnel lens part 5 composed of corresponding uneven part M
A.

The groove depth t of the saw-toothed uneven portion M for maximizing the light-collecting efficiency of the lens depends on the refractive index n of the p-type Al _0.5 Ga _0.5 As cladding layer 5 and the Al _0.13 Ga _0.87 As active layer 4.
It is necessary to satisfy the relationship of λ / (n−1) using the wavelength λ emitted from. In this case, Al _0.13 Ga
_0.87 The wavelength λ of the light emitted from the As active layer 4 is 780 n
m, since the refractive index n of the p-type Al _0.5 Ga _0.5 As cladding layer 5 is 3.6, the groove depth t is 0.3 μm. Further, the p-type GaAs is formed on the end 5B of the p-type Al _0.5 Ga _0.5 As clad layer 5 except for the Fresnel lens portion 5A.
A contact layer 6 and a p-type electrode 7 are sequentially formed, and an n-type electrode 8 is formed on the n-type GaAs substrate 2 on the side opposite to the laminating direction.

Next, the operation of the semiconductor light emitting device 1 of the present invention will be described. A current is injected from the p-type electrode 7 side of the semiconductor light emitting device 1 toward the n-type electrode 8 side, and Al _0.13 Ga
Light is emitted from the _0.87 As active layer 4, and the emitted light is converged by the Fresnel lens portion 5A and is emitted above the p-type electrode 7. In this case, the Al _0.13 Ga _0.87 As active layer 4 becomes a light emitting region.

[0010] Thus, Al _0.13 Ga _0.87 Fresnel lens portion 5A for converging the light emitted from the As active layer 4 on top of the Al _0.13 Ga _0.87 As active layer 4 p-type Al
_{Since a part of the 0.5} Ga _0.5 As clad layer 5 is processed, the Fresnel lens portion 5 A can also be integrally manufactured by using a semiconductor process. The alignment between the 5A and the light emitting region can be performed with high accuracy and at low cost.

Next, a method for manufacturing the semiconductor light emitting device 1 of the present invention will be described with reference to FIG. (First Step) As shown in FIG. 2A, an n-type Al _0.5 Ga _0.5 As clad layer 3 is formed on an n-type GaAs substrate 2.
_{A 0.13} Ga _0.87 As active layer 4, a p-type Al _0.5 Ga _0.5 As clad layer 5, and a p-type GaAs contact layer 6 are formed, an electron beam resist is applied, and a p-type GaAs contact layer is formed by electron beam lithography and ion etching. 6. Remove the center of 6.

(Second Step) As shown in FIG.
Type Al_0.5Ga_0.5As cladding layer 5 and p-type GaAs layer
An electron beam resist is applied on the contact layer 6. Next
Next, as shown in FIG.
P-type Al _0.5Ga_0.5Center of As clad layer 5
A Fresnel lens pattern 10 is formed in the portion.

(Third Step) Next, as shown in FIG. 2 (D), ion beam etching is performed to transfer the Fresnel lens pattern 10 to the p-type Al _0.5 Ga _0.5 As clad layer 5, and to form saw-tooth irregularities. Fresnel lens portion 5 having portion M
Form A. At this time, by controlling the coating thickness of the electron beam resist 9, the groove depth t of the uneven portion M is optimized. It is to be noted that the portion having the uneven portion M acts as the Fresnel lens, and the portion without the uneven portion M may be made of another material. (Fourth Step) Thereafter, the Fresnel lens pattern 10 is removed, and the p-type GaAs contact layer 6 and the p-type electrode 7 are formed on the end 5B of the p-type Al _0.5 Ga _0.5 As clad layer 5 excluding the Fresnel lens portion 5A. Are sequentially formed, and an n-type electrode 8 is formed on the n-type GaAs substrate 2 on the side opposite to the laminating direction to obtain the semiconductor light emitting device 1 shown in FIG.

In the embodiment of the present invention, AlGaAs is used.
Although the system-based semiconductor light emitting device has been described, similar effects can be obtained in the case of an InP-based semiconductor light emitting device. In addition, the same effect can be obtained not only for the semiconductor light emitting device but also for an edge emitting type or surface emitting type semiconductor laser device. Further, the Fresnel lens portion 5A is not limited to a semiconductor material, but may be a material such as a dielectric layer.

[0015]

According to the semiconductor light emitting device of the present invention, a part of the upper semiconductor layer is processed in the direction of the light emitted from the light emitting region and above the light emitting region in the semiconductor layer. Since it has a Fresnel lens part, the Fresnel lens part can also be manufactured integrally with the semiconductor process, so that the lens required conventionally is unnecessary, and the alignment between the Fresnel lens part and the light emitting region can be performed with high accuracy.
And it can be inexpensive.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a semiconductor light emitting device of the present invention,
(A) is a sectional view, and (B) is a plan view.

FIG. 2 is a diagram illustrating a method for manufacturing an embodiment of the semiconductor light emitting device of the present invention.

[Explanation of symbols]

1 ... semiconductor light emitting element, 2 ... n-type GaAs substrate (substrate),
3. n-type Al _0.5 Ga _0.5 As clad layer (semiconductor layer)
4 ... Al _0.13 Ga _0.87 As active layer (light emitting region), 5 ... p
Type Al _0.5 Ga _0.5 As clad layer (upper semiconductor layer), 6
... p-type GaAs contact layer (upper semiconductor layer), 7 ... p
Type electrode, 8 ... n-type electrode, 9 ... electron beam resist, 10
... Fresnel lens pattern, 5A ... Fresnel lens part,
M: Uneven part

Claims (1)

[Claims] 1. A semiconductor light emitting device having a plurality of semiconductor layers including a light emitting region formed on a substrate, wherein said light emitting region is in a direction of light emitted from said light emitting region and said light emitting region of said semiconductor layer A semiconductor light emitting device having a Fresnel lens portion obtained by processing a part of an upper semiconductor layer formed on the upper surface of the light emitting device, wherein the emitted light is converged by the Fresnel lens portion.