JPH02188971A - Semiconductor photoreceptor element - Google Patents

Abstract

PURPOSE:To obtain a semiconductor photoreceptor element which can detect rays of light of various wavelengths in a multiplexed state by epitaxially growing materials having different lattice constants after piling up them on the same substrate. CONSTITUTION:This semiconductor photoreceptor element is provided with at least one set of a laminated structure composed of the first semiconductor layer 1 of the first conductivity type, first semiconductor layer 2 of the second conductivity type, second semiconductor layer 4 of the first or second conductivity type, and second semiconductor layer 5 of the second or first conductivity type and the first and second semiconductor layers 1 and 2 and 4 and 5 are made to have different lattice constants. For example, a laminated structure composed of an n-GaAs layer 5, p-GaAs layer 4, GaAs buffer layer 3, p-InGaAs layer 2, and n-InGaAs layer 1 is formed on an n-GaAs substrate 6. When signal rays of light having wavelengths of lambda=0.8mum and lambda=0.13mum are made incident on the structure as incident light 10, the light having the wavelength lambda=1.3mum is absorbed into the InGaAs layers 1 and 2 after passing through the GaAs layers 3-6, while the light having the wavelength of lambda=0.8mum is absorbed into the GaAs layers 4-6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wavelength multiplexing semiconductor light receiving element.

[Conventional technology]

Figure 2 shows, for example, Applied, Physics, Letter 35
PP, 588 is a cross-sectional view showing a conventional wavelength multiplexing semiconductor light receiving element.
The aAsP layer and the square are P-1nGaAsP layers, and both have a forbidden band width of 1.55 μm for Al. Time is P-1nP, Q
4 is P-I nGaAs P layer, 4 is n-1nGaAs
Both are prohibited in the P layer.

The obtained width is 1.3 μm for Al. aQ is n-1nP
It is a board.

Next, the operation will be explained. Wavelength λ=1.3 μm, 1.
Let us consider the case where a mixture of 55 μm diameters is incident.

Since the lnP substrate αQ and the lnP layer are transparent to light of both wavelengths, the light passes through. InGaAsP layer a4. The forbidden band width of U and 1nGaAsP layer uXla is λp=1
．． 3 μm.

Since 1.55 μm is selected for each, the light of λ = 1.3 μm is absorbed by the 1nGaAsP layer a4) and ofj,
The light of λ=1.55μm is 1nGaAsP Jl (14,
After passing through Cm, it is absorbed at a. P-1nGaAsP layer (b) between electrodes (7) and (8)
.

A voltage was applied so that the n-1nGaAsPJl east was reverse biased, and the P-1nGaAs
When a voltage is applied so that the AsP layer (b) and n-InGaAsP111QIi are reverse biased, the output terminal becomes 0UTI.
, The signal output from λ-155#m light is between OUT 2, and λ = 1.3μ between output terminals OUT 2 and OUT 3.
Signal outputs from m lights are obtained, respectively. Therefore, λ=1.3 μm due to the semiconductor photodetector with the cylindrical structure.

Signal light of two wavelengths of 1.55 μm can be detected independently.

[Problem to be solved by the invention]

Conventional semiconductor light-receiving devices were configured as described above, so they could only detect wavelengths within the forbidden band determined by the crystal composition that matches the substrate and lattice layer, and there were also restrictions on the selection of signal wavelengths. For example, if GaAs is selected as the substrate, there is a problem in that the wavelength range in which light can be received is only a wavelength of 0.87 μm or less.

This invention was made to solve the above-mentioned problems, and aims to increase the selection ratio of signal wavelengths by combining different materials for use in semiconductor light-receiving elements.

[Means to solve the problem]

The semiconductor light-receiving device according to the present invention allows the combination of different types of semiconductor layers as materials for the light absorption layer by epitaxially growing thin films with different lattice constants via a buffer layer.

[Effect]

In this invention, the combination of different types of semiconductor layers increases the variety of materials used for the light absorption layer and allows a wide variety of signal waveforms to be selected.

[Embodiment J Hereinafter, one embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, (1) is an n-InGaAs layer, (2, 1 is a P-InGaAs layer, and both have a forbidden band width of λII
= 1.65 μm. (3) is a GaAs buffer layer, (4) is a P-GaAs layer, (5) is an n-GaAs layer,
(6J n-GaAs substrate, (7), (8), (9
] are electrodes for applying a bias voltage and extracting a signal.

Here, the GaAs buffer layer (3) is made of GaAs and InG.
This layer was formed to alleviate the approximately 4% lattice mismatch between aAs, and this buffer layer (3)
Epitaxial growth of As and InGaAs becomes possible.

Next, the operation will be explained. As incident light αq, λ=0.
Consider signal light with two wavelengths of 8 μm and 1.3 μm.

Since GaAs is transparent to light of 1.3 μm, light of 1.3 μm is exposed to the GaAs layer (3), (
4), (5), (13-, transmitted through InGaA
It is absorbed in the s layer (11, (2). On the other hand, λ = 0.8μ
The light of m is absorbed by the GaAs layer (4J, (5), (61). Electrode (7).

(8) n-InGaAs layer (1) between, P-InGaA
A voltage is applied so that the s-layer (2) becomes reverse biased, and the electrode (
8), (9) 8 layers of P-Cy a A (4)
A reverse bias is applied between the %n-GaAs layers (5).

Apply voltage accordingly. By doing this, the output end becomes 0.
A signal from light with λ=1.3 μm is detected between UTI and 0UT2, and a signal from light with λ=0.8 μm is detected between output ends 0UT2 and 0UT3. In this way, by newly introducing the InGaAs layer as a light absorption layer, the light reception wavelength band when using a GaAs substrate is expanded from the conventional 0.87 μm or less to 1.65 μm or less, and the currently commercialized 0. , it becomes possible to simultaneously receive light from the semiconductor light emitting device in the 8 μm band and the 1 μm band.

In the above example, the case where the lnGaAs layer and the GaAs layer were selected as the materials was shown, but this combination can be applied to any crystal that can be grown epitaxially, and Although the case where different types of materials are selected is shown, the same effect can be obtained by stacking three or more types of materials in a laminated structure.

Further, the same effect can be obtained even if a buffer layer is provided between the first semiconductor layer and the second semiconductor layer.

[Effects of the Invention] As described above, according to the present invention, since materials with different lattice constants are epitaxially grown on the same substrate, it is possible to obtain a semiconductor light-receiving element that can multiplexly detect light of various wavelengths. .

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a semiconductor light-receiving device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a conventional semiconductor light-receiving device. In the figure, (1) is an n-InGaAs layer i21 is a P-InGaAs t'fl, (3] is a GaAs layer, (
3) is a GaAs buffer layer, (4) is a P-GaAs layer,
(5) is n GaAs rm, (6) is n -GaA
s substrate, (7) is the first electrode, (8) is the second electrode,
(9) indicates the third electrode, and Kei indicates the incident light. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] From a first semiconductor layer of a first conductivity type, a first semiconductor layer of a second conductivity type, a second semiconductor layer of the first or second conductivity type, a second semiconductor layer of the second or first conductivity type. 1. A semiconductor light-receiving device comprising at least one set of semiconductor layers in a laminated structure comprising a first semiconductor layer and a second semiconductor layer having different lattice constants.