JPS62291978A - Semiconductor photodetector - 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] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a semiconductor light receiving device, in particular, a device that absorbs visible light,
The present invention relates to a semiconductor light receiving device that transmits near-infrared light.

[Prior art]

Conventionally, there have been two methods for measuring visible light intensity and near-infrared light intensity from one light beam. In other words, the light beam is divided by a light splitting member such as a half mirror, and each A method of measuring by dividing into a visible light sensor and a near-infrared light sensor that are highly sensitive in the wavelength range and guiding nine light beams, or a method in which the spectral sensitivity distribution of a single-crystal silicon photodiode, etc. is used as a light receiving sensor in the visible range A light receiving sensor that extends into the near-infrared region is used, and in front of this light receiving sensor, a near-infrared cut filter is installed for visible light measurement, and a visible light cut filter is installed for near-infrared light measurement. This is a good way to measure it.

[Problem that the invention seeks to solve]

However, in the above conventional methods, the former method requires a light splitting member between the visible light sensor and the near-infrared light sensor, and the latter method requires an optical filter to be provided in front of the light receiving sensor. This method had a problem in that visible light intensity and near-infrared light intensity could not be measured simultaneously.

In view of the above problems, an object of the present invention is to provide a visible light sensor that absorbs visible light and transmits near-infrared light, thereby reducing the number of optical components and providing a compact optical device. [Means for solving the problem] The above problem consists of a first transparent electrode formed on a transparent substrate, and a - conductivity type second electrode formed on the first transparent electrode. a first amorphous semiconductor region, a second amorphous semiconductor region formed on the first amorphous semiconductor region, and a second amorphous semiconductor region formed on the first amorphous semiconductor region;
a third amorphous semiconductor region of opposite conductivity type to the first amorphous semiconductor region formed on the amorphous semiconductor region; and a third amorphous semiconductor region formed on the third amorphous semiconductor region. This problem is solved by the semiconductor light receiving device of the present invention having two transparent electrodes.

[Effect]

In the semiconductor light receiving device of the present invention, a transparent electrode is formed on a transparent substrate, and a pin type photodiode is formed using an amorphous semiconductor that can be formed on the transparent electrode. ! , formed in the evening sky, further forming a transparent electrode on this photodiode, irradiating the incident light to the photodiode through one of the transparent electrodes, and absorbing the visible region of the incident light by this photodiode, When incident light in the near-infrared region is transmitted, this near-infrared light is transmitted through the other transparent electrode.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an example of the configuration of a semiconductor light receiving device of the present invention.

In FIG. 1, 1 is a transparent substrate such as glass, which is a transparent substrate; 2 is a transparent electrode formed on the transparent substrate 1, and is made of ITOt 5n02 or the like. 3 is a p-type amorphous layer (hereinafter referred to as p layer) which is a p-type amorphous region formed on the transparent electrode 2, and is made of hydrogenated amorphous silicon doped with 2m impurities such as B (hereinafter referred to as a-8t: H), hydrogenated amorphous gas silicon carbide, heptad system amorphous silicon (hereinafter referred to as a-8I:H:F) p 7,
Such as amorphous silicon carbide. 4 is 2
The amorphous layer (hereinafter referred to as 1 layer), which is an amorphous region formed on layer 3, exhibits intrinsic semiconductor characteristics, a-8t:H, a-
81:H:F, a-81:H, a without adding impurities
-8t:H:F, a-81:H, a-8l:H:F, etc. to which a p-type impurity such as B of 40 ppm or less is added. Note that usually a-8i:H, a-8i:H:F l
When no dP fin impurity is added, it exhibits weak n-type semiconductor characteristics, and if necessary, p-type impurities are added to make it closer to an intrinsic semiconductor.

Note that if it exceeds 40 ppm, it will exhibit p-type semiconductor characteristics. 5 is an h-type amorphous layer (hereinafter referred to as n-layer) which is an n-type amorphous region formed on layer 4, and is doped with an n-type impurity such as P: a-8i:H+ a-8i: H:F
, or amorphous silicon that does not contain H, F, or the like. 6 is a transparent 'c' electrode formed on one layer 5 of ITO.

Sn02 etc.

Hereinafter, the embodiments of the semiconductor light receiving device of the present invention will be congratulated.

A glass substrate is used as the transparent substrate 1. ITO is formed on this glass substrate to a thickness of 100OX, and SnO□
was formed to have a thickness of 200X, and a transparent electrode 2 was provided. Furthermore, 2 exhibiting p-type semiconductor characteristics with B added on the transparent electrode 2
Provide two layers 3 of a-81:H layer with a thickness of 00X, and
6000mm thick a-8 without doping on layer 3
One layer 4 of l:H layer is provided, and on this one layer 4, a-8i:H with a thickness of 500X exhibiting n-type semiconductor characteristics with P added.
An n-layer 5 of layers was provided. Furthermore, a transparent electrode 6 of ITO with a thickness of 1000× was provided on the layer 5.

Said p layer 3. i-layer 4. The n-layer 5 was deposited by the plasma cyp method, and the transparent electrodes 2 and 6 were deposited by the sputtering method.

2 layers 3, 1 layer 4. The n-layer 5 constitutes a pin-type photodiode, and when light is incident from the transparent substrate 1 side, it exhibits the following characteristics.

FIG. 2 is a characteristic diagram showing the voltage-current characteristics of the photodiode.

In FIG. 2, 7 is a characteristic diagram when no light is incident, and 8 is a characteristic diagram when green light is irradiated (1001[IX)l], showing good photodiode characteristics.

FIG. 3 is a characteristic diagram showing the spectral and multiplicity characteristics of the photodiode.

As shown in FIG. 3, the photodiode of this example is close to the ratio window curve, indicating that it is a good visible light sensor.

FIG. 4 is a characteristic diagram showing the spectral transmittance of the photodiode.

As shown in Figure 4, almost no light in the visible region with energy greater than the energy of the a-8i:H bandgap is transmitted, and the photodiode of this example serves as a good visible cut filter. I understand that.

In the infrared region, fluctuations in transmittance due to multiple interference can be seen.
Although there are wavelengths that are difficult to transmit, it is possible to use this to control the transmittance of specific wavelengths by changing the layer thickness of each amorphous semiconductor layer.

In the above embodiment, the thickness of each amorphous semiconductor layer is equal to the light of the photodiode! , and may be arbitrarily set within the permissible range of the absorption characteristics as a visible light cut filter. Furthermore, in FIG. 1, 2 layers 3 degrees, 1 layer 4 degrees. Although the a-layer 5 is laminated in this order, the n-layer 5 and the two-layer 3 may be alternately laminated. Further, the incident light may be irradiated from the transparent electrode 6 side.

Next, an application example of the semiconductor light receiving device of the present invention will be shown.

FIG. 5 is a schematic diagram illustrating a distance measuring optical system and a photometric optical system of a camera using the semiconductor light receiving device of the present invention.

In FIG. 5, an I provided inside the camera body 9
Near-infrared light emitted from JD 10, e.g. 860 a
The near-infrared light t of m is irradiated onto the subject 12 through the Fi projection optical system 11 . The near-infrared light t1 reflected by the subject 12 passes through the light-receiving optical system 13 and the photodiode 14, which is a semiconductor light-receiving device of the present invention, and has a visible light filter function, and enters the ranging sensor 15. .

The distance between the subject 12 and the camera body 9 is determined by the LED
10 and the projection optical system 11 to change the emission angle of the near-infrared light t1, and find the emission angle when the near-infrared light t is incident on the distance measuring sensor 15. It is measured by

On the other hand, visible light t2 reflected from the subject 12 passes through the light receiving optical system 13 and is irradiated onto the photodiode 14, where photometry is performed and information necessary for controlling the exposure amount is obtained.

The visible light t2, which also becomes noise in the ranging signal, is absorbed by the photodiode 14 and does not enter the ranging sensor 15.

That is, by using the semiconductor light receiving device of the present invention, the distance measuring sensor and the seven photodiodes serving as the photometric sensor can be arranged side by side on the optical axis of the light receiving optical system, without the need for optical components such as a light splitting member. Moreover, the optical device can be designed compactly.

〔Effect of the invention〕

As described in detail above, according to the semiconductor light receiving device of the present invention, a transparent electrode is formed on a transparent substrate, an amorphous semiconductor region is formed on this transparent electrode to constitute a photodiode, and By forming a transparent layer on this photodiode, it is possible to provide a visible light sensor that functions as a visible light cut filter. INDUSTRIAL APPLICATION This invention is suitably used for the optical device which measures visible light intensity and near-infrared light intensity simultaneously.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of the configuration of a semiconductor light receiving device of the present invention. FIG. 2 is a characteristic diagram showing voltage-current characteristics of a photodiode. FIG. 3 is a characteristic diagram showing the spectral sensitivity characteristics of the photodiode. FIG. 4 is a characteristic diagram showing the spectral transmittance of the photodiode. FIG. 5 is a schematic diagram illustrating a distance measuring optical system and a photometric optical system of a camera using the semiconductor light receiving device of the present invention. 1...Transparent substrate, 2.6...Transparent electrode, 3...p
type amorphous layer, 4... amorphous layer, 5... n-type amorphous layer. Agent Patent Attorney Minoru Yamashita

Claims (1)

[Claims] a first transparent electrode formed on a transparent substrate;
a first amorphous semiconductor region of one conductivity type formed on a transparent electrode, a second amorphous semiconductor region formed on this first amorphous semiconductor region, and a second amorphous semiconductor region formed on this first amorphous semiconductor region; a third amorphous semiconductor region formed on the amorphous semiconductor region and having a conductivity type opposite to that of the first amorphous semiconductor region; and a second amorphous semiconductor region formed on the third amorphous semiconductor region. A semiconductor light receiving device having a transparent electrode.