JPH02117181A - Semiconductor light receiving device - Google Patents

Abstract

PURPOSE:To easily integrate electrodes of each area with electronic circuits disposed on an insulating substrate by providing a first n-type area and a second p-type area in a semiconductor layer provided on a semiinsulating substrate spaced from each other and providing the electrodes of each area in the same flat plane. CONSTITUTION:An n<+>-type first area 10 disposed on a semiconductor layer 2 is formed as an area which leads to a substrate 9 from the surface of the semiconductor layer 2. Likewise, a second p<+>-type area 11 disposed on the semiconductor layer 2 is formed at a place spaced from the first area as an area which leads to the substrate 9 from the surface of the semiconductor layer 2. An n electrode 12 provided on the first area 10 protrudes on the surface of an insulation film through it. A p electrode 13 provided on the second area 11 passes through the insulation film 5 in the same manner as the n electrode and protrudes on the surface. Since the electrodes 12, 13 of the first and second area 10 and 11 are disposed on the same plane, they can be formed on the substrate 9 on which electronic circuits are mounted and therefore integration with electronic circuits is easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in semiconductor light receiving devices such as avalanche photodiodes.

[Conventional technology]

FIG. 3 is a sectional view showing the schematic structure of a conventional avalanche photodiode. In this figure, (1) is n”
-GaAs substrate (2 is n--G provided on its top surface)
The aAs layer (3) is the p layer formed on the n-GaAs layer.
The + region (4) is a p-type guard ring region formed around the ρ1 region, (51 is an insulating film provided on the surface of the n-GaAs layer, and (6) is the p+ region provided The p-electrode penetrates the insulation M (51) and protrudes from the surface thereof. (7) is the n-electrode provided on the lower surface of the substrate.
The electrode (8) is the irradiated light.

In such a configuration, when a reverse voltage is applied between the p-electrode (6) and the n-electrode (6) and photoelectric is irradiated, this light (
Reference numeral 81 indicates generated electrons which are absorbed by the n-GaAs layer (2) constituting the light receiving section and generate electron-hole pairs.

Holes are formed on n”-GaAs substrate (1) and n7-GaA5J
The electric field inside Wt(2) causes them to travel in opposite directions, and as a result, they are taken out as photocurrent. When the voltage applied between the two electrodes from the outside is increased, the traveling electrons or holes acquire sufficient acceleration energy in the semiconductor, and generate new electron-hole pairs in the scattering process with phonons. The newly generated electrons or regular bills are accelerated again, and new electron/hole pairs are generated through the same process, so-called avalanche multiplication, and thereafter, electron/hole pairs are generated in a chain reaction. .

As a result, the photocurrent is also multiplied and taken out to the outside. Note that the voltage applied to the picture electrode is close to the breakdown voltage of the p-n junction, and therefore, local junction breakdown is likely to occur in areas with high curvature of the p-n junction, so the purpose of curvature relaxation is A guard ring area (a) is provided.

[Problem to be solved by the invention]

Conventional semiconductor photodetectors are constructed as described above, with electrodes provided on the top and bottom surfaces of the device, making it difficult to integrate with electronic circuits, etc. arranged on a semi-insulating substrate. There was a problem.

This invention was made to solve the above-mentioned problems, and aims to provide a semiconductor light receiving device that can be easily integrated with electronic circuits etc. arranged on a semi-insulating substrate. .

[Means to solve the problem]

A semiconductor light receiving device according to the present invention includes a semiconductor layer of a first conductivity type on a semi-insulating semiconductor substrate, and a first region of a highly concentrated first conductivity type and a semiconductor layer of a second conductivity type in the semiconductor layer. The electrodes of the first region and the second region are provided on the same surface.

[For production]

According to this invention, since the electrodes of the first region and the second region are provided on the same plane, it is possible to form the electrodes on a semi-insulating substrate on which electronic circuits, etc. are arranged. It also facilitates integration.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a cross-sectional view showing the configuration of the embodiment, and in this figure (9
) is a semi-insulating GaAs substrate, and (21 is an n-GaAs semiconductor layer provided on the substrate, which acts as a light absorption layer and a multiplication layer for the irradiated light 6). 1 is an n+ type first region provided in the semiconductor layer (a), and is formed as a region extending from the surface of the semiconductor layer (2) to the substrate (9). (2) is a p+ type second region provided at a location separated from the first region, and is formed as a region extending from the surface of the semiconductor layer (2) to the substrate (9). (51 is An insulating film provided on the surface of the semiconductor layer (2), (12
) is an n-electrode provided in the first region, which penetrates the insulating film (51) and protrudes from the surface thereof. (13) is an n-electrode provided in the second region (11), Like the n-electrode, it penetrates the insulating film (5) and protrudes from the surface thereof.

In such a configuration, the n-electrode (12) and the n-electrode <1
3) When a reverse voltage is applied between the first area α■ and the second area
A lateral electric field is formed in the semiconductor layer (2) between the region (11) and the semiconductor layer (2). When light (a) is irradiated in this state, the light θ
is absorbed within the semiconductor layer (2) and generates electron-hole pairs. As described above, when the applied voltage is sufficiently increased, avalanche multiplication occurs, and the multiplied photocurrent is taken out to the outside.

In this case, local junction breakdown at the high curvature part of the pn junction becomes a problem, but in the above embodiment, the first region αω
The second region (11) is formed sufficiently deep within the semi-insulating substrate (9) so that a region with high curvature is formed within the substrate (9), thereby preventing local junction breakdown. It is something that can be done.

However, if local junction breakdown occurs even with such a configuration, a guard ring layer (14) is provided between the substrate (9) and the semiconductor layer (2) as shown in FIG. The first area 00) and the second area (11) may each reach the guard ring /lW (+41).

The guard ring layer (14) is made of AlGaAs with a wide forbidden band width.
Alternatively, G having an even lower impurity concentration than the semiconductor layer (2)
It is made of aAs or AlGaAs. In addition, in the above explanation, GaAs, AlG5A are used as materials for each layer.
Examples using s are given, but the invention is not limited to this, and other semiconductor materials such as InP, InGaAs
P, InGaAs or CdTe, HgCdTe
Alternatively, similar effects can be expected by using AlGaSb, AlGaAsSb, or the like.

〔Effect of the invention〕

The present invention is constructed as described above, in which an n-type first region and an n-type second region are provided separately from each other in a semiconductor layer provided on a semi-insulating substrate, and the electrodes of each region are arranged on the same plane. Since the structure is designed to be easily integrated with electronic circuits and the like disposed on a semi-insulating substrate, it is easy to integrate the device with electronic circuits and the like arranged on a semi-insulating substrate.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing one embodiment of the present invention, FIG. 2 is a schematic sectional view showing another embodiment of the invention, and FIG. 3 is a schematic sectional view showing a conventional semiconductor light receiving device. In the figure, (9) is the substrate, (2) is n''-GaAs
of the semiconductor layer, α[ is the first region, (11) is the second region, (
9 is an insulating film, (12) is an n-electrode, (13) is an n-electrode, (
14) is a guard ring layer. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Fig. 1 Fig. 2 Agent Patent Attorney Masuo Oiwa / 4: 77-)'Lymph 4 Snow Fig. 3 Indication of workability 1985 Patent Application No. 271.324 2 Name of the invention Semiconductor photodetector device 37 cities Person(s) making the amendment: $1' Totopi] Related: 1) Representative of the applicant; 4) Detailed explanation of the invention in the specification to be amended; 6) Contents of the amendment; 2nd page, line 13 of the specification; [And... in (2)," is corrected to read, "There is a gap between and the P+ GaAs region (3)."that's all

Claims (1)

[Claims] A semiconductor layer of a first conductivity type provided on a semi-insulating semiconductor substrate and constituting a light-receiving section; a first region of a conductivity type; a second region of a second conductivity type provided in the semiconductor layer at a distance from the first region and forming a region extending from the surface of the semiconductor layer to the semiconductor substrate; A semiconductor light receiving device including resistive electrodes provided in a region and a second region.