JPS6244866B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a semiconductor photodetection device.

Conventionally, as shown in FIG. 1, a P-type semiconductor layer 3 is formed on an N-type semiconductor substrate 1 to form a PN junction 2 as shown in FIG. A configuration has been proposed in which an electrode 5 is attached to the main surface 4 on the opposite side in an ohmic manner.

By the way, in the semiconductor photodetecting device having such a configuration, the electrode 5
A bias power supply 6 that provides a reverse bias to the PN junction 2 is connected between the semiconductor layer 3 and the semiconductor layer 3, and light 7 is incident from the semiconductor layer 3 side in a state where a depletion layer is formed that spreads from the PN junction 2 mainly toward the semiconductor substrate 1 side. If possible, a corresponding photocurrent is applied to the electrode 5 and the semiconductor layer 3.
However, as shown in Fig. 2, its spectral sensitivity changes depending on the depth D of the PN junction 2, and when the depth D of the PN junction 2 is small, The more it is, the more sensitive it is over a wider wavelength range. The lower limit of the sensitive wavelength range is determined by the band gap of the semiconductor substrate 1 and the semiconductor layer 3, and the upper limit is determined by the reflection of the surface layer,
It is limited by absorption.

However, in the case of the semiconductor photodetector shown in FIG. 1, it is difficult to reduce the depth D of the PN junction 2 in order to obtain sensitivity over a wide wavelength range. It was difficult to obtain sensitivity.

For this reason, conventionally, as shown in _FIG .
A semiconductor having a structure in which an electrode 14 is attached to an ohmic on the side opposite to the SiO ₂ film 13 of No. 1, and an electrode 16 is attached to the N-type layer 12 through a window 15 formed in the SiO ₂ film 13. Photodetection devices have been proposed.

By the way, in the case of a semiconductor photodetector having such a configuration, since the PN junction 17 is formed between the semiconductor substrate 11 and the N-type layer 12, the electrodes 14 and 16
A bias power supply 6 is connected in between to reverse bias the PN junction 17, and a PN junction 1 is formed in the semiconductor substrate 11.
If light 7 is irradiated with a depletion layer expanding from 7, a photocurrent can be obtained through electrodes 14 and 16 as in the case of Fig. 1, but this semiconductor photodetector cannot be reproduced. It has the disadvantage that it is difficult to obtain with good quality.

Further, as shown in FIG. 4, for example, an N-type semiconductor substrate 2
1, a metal electrode 23 is attached to one side of the semiconductor substrate 21 to form a shot junction 22, and an electrode 24 is ohmic attached to the opposite side of the semiconductor substrate 21 from the metal electrode 23 side. Devices have also been proposed in the past.

However, in the case of a semiconductor photodetector having such a configuration, a shot junction 2 is formed between the electrodes 23 and 24.
If the bias power supply 6 is connected to reverse bias the electrode 23 and the light 7 is irradiated with the semiconductor substrate 21 forming a depletion layer extending from the Schottky junction 22, the electrode 23 and 24
However, since the reflection loss of the light 7 at the metal electrode 23 is large, it has the disadvantage of poor efficiency, and it is difficult to form a good shot junction 22. It had drawbacks such as being difficult.

Therefore, the present invention aims to propose a novel semiconductor photodetection device free from the above-mentioned drawbacks, which will become clear from the detailed description below.

FIG. 1 shows a first diagram of a semiconductor photodetection device according to the present invention.
For example, in an N-type semiconductor substrate 51, a plurality of PN junctions 53a,
P type semiconductor region 54 to form 53b...
a, 54b... are formed.

Further, the main surface 5 opposite to the main surface 52 of the semiconductor substrate 51
5, an electrode 56 is attached to the ohmic.

Further, in the semiconductor substrate 51, from the main surface 52 side, a plurality of N ⁺ type electrode semiconductor regions 57a, 57b...
... are arranged between the semiconductor regions 54a and 54b and between 54b and 54c.

Furthermore, an electrode 56 and semiconductor regions 57a and 57b
. . are connected to one end of the bias power supply 6, and the semiconductor regions 54a, 54b, . . . are connected to the other end (ground) of the bias power supply 6.

The above is the configuration of the first embodiment of the semiconductor photodetection device according to the present invention. According to this configuration, the bias power supply 6 is
If we assume that the polarity is such that a reverse bias is applied to...
PN junctions 53a, 53b... in the semiconductor substrate 51
As a result, a depletion layer extending vertically toward the electrode 56 and a depletion layer extending laterally toward the semiconductor regions 57a, 57b, . . . are formed.

Therefore, the semiconductor substrate 51, the semiconductor region 54a,
54b... and the electrode 56 to constitute a plurality of vertical photodiodes VDa, VDb..., and the semiconductor substrate 51 and the semiconductor regions 54a, 54b...
and semiconductor regions 57a, 57b, . . . to constitute a plurality of horizontal photodiodes LDa, LDb, .

Therefore, if the light 7 is made incident from the main surface 52 side of the semiconductor substrate 51, the vertical photodiodes VDa,
The photocurrent due to VDb... is transferred between the electrode 56 and the semiconductor region 5.
4a, 54b..., and the photocurrent from the lateral photodiodes LDa, LDb... can be obtained via the semiconductor regions 54a, 54b... and the semiconductor regions 57a, 57b... It is possible.

For this reason, sensitivity in the long wavelength region can be obtained with the vertical photodiodes VDa, VDb..., and sensitivity in the short wavelength region can be obtained with the horizontal photodiodes LDa, LDb... Overall, it has a great feature of being able to obtain sensitivity over a wide wavelength range.

Next, a second embodiment of the present invention will be described with reference to FIG. 6. Parts corresponding to those in FIG. In the configuration described above, the electrode 56 and the semiconductor region 57
a, 57b... are connected to the bias power supply 6 via the changeover switch 60.
It has the same configuration as the case in FIG.

The above is the second embodiment of the semiconductor photodetection device according to the present invention. According to this configuration, it has the same configuration as the case of FIG. 5 except for the matters mentioned above, so detailed explanation will be omitted. Although this is omitted, by switching the changeover switch 60, the vertical photodiode
By selecting VD _a , VD _b ..., the light 7 can be detected mainly in the long wavelength region, and by selecting the horizontal photodiodes LD _a , LD _b ..., the light 7 can be detected mainly in the short wavelength region. It has great characteristics that can be detected in a wide range of areas.

Next, a third embodiment of the present invention will be described with reference to FIG. 7. Parts corresponding to those in FIG. 6 will be given the same reference numerals and detailed explanation will be omitted. In a configuration in which a plurality of semiconductor regions 54a, 54
The configuration is the same as that in FIG. 6, except that b... is selected by the changeover switch 62.

The above is the configuration of the third embodiment of the semiconductor photodetection device according to the present invention. According to this configuration, since it has the same configuration as the case of FIG. 6 except for the matters mentioned above, the switching By switching the switches 60 and 61, a plurality of vertical photodiodes VDa,
VDb... selection and multiple horizontal photodiodes
It has the great feature of being able to detect the long wavelength region of the light 7 and the short wavelength region by selecting LDa, LDb, . . . .

The above description merely shows a few embodiments of the present invention, and various modifications and changes may be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a conventional semiconductor photodetector, FIG. 2 is a curve diagram for explaining the same, FIGS. 3 and 4 are schematic diagrams showing a conventional semiconductor photodetector, and FIG. , FIG. 6, and FIG. 7 are schematic diagrams showing first, second, and third embodiments of the semiconductor photodetection device according to the present invention, respectively.

Claims (1)

[Claims] 1. A semiconductor substrate having a first conductivity type, which is opposite to the first conductivity type, is formed from the first main surface side to form a first PN junction. a first PN junction forming semiconductor region having a second conductivity type; and a first electrode or a first conductivity type formed on a second main surface side of the semiconductor substrate opposite to the first main surface. a second electrode semiconductor region formed on the first main surface side of the semiconductor substrate or a second electrode semiconductor region having a first conductivity type; A first vertical photodiode is configured including a semiconductor substrate, the first PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; A semiconductor photodetecting device characterized in that a first lateral photodiode is configured including a semiconductor region for forming a PN junction, and the second electrode or the semiconductor region for the second electrode. 2 A semiconductor substrate having a second conductivity type opposite to the first conductivity type formed from the first main surface side to form a first PN junction in a semiconductor substrate having a first conductivity type. a first PN junction forming semiconductor region; and a first electrode formed on a second main surface side opposite to the first main surface of the semiconductor substrate or a first electrode having a first conductivity type. a second electrode semiconductor region formed on a first main surface side of the semiconductor substrate or a second electrode semiconductor region having a first conductivity type; A first vertical photodiode is configured including the semiconductor region for forming a PN junction, and the first electrode or the semiconductor region for the first electrode, and the semiconductor substrate and the first semiconductor for forming a PN junction. and the second electrode or the second electrode semiconductor region, a first horizontal photodiode is configured, and the first vertical photodiode and the first
1. A semiconductor photodetection device comprising a first bias power supply means for supplying a common bias power supply to horizontal photodiodes. 3 A semiconductor substrate having a second conductivity type opposite to the first conductivity type formed from the first principal surface side to form a first PN junction in a semiconductor substrate having a first conductivity type. a first PN junction forming semiconductor region; and a first electrode formed on a second main surface side opposite to the first main surface of the semiconductor substrate or a first electrode having a first conductivity type. a second electrode semiconductor region formed on a first main surface side of the semiconductor substrate or a second electrode semiconductor region having a first conductivity type; A first vertical photodiode is configured including the semiconductor region for forming a PN junction, and the first electrode or the semiconductor region for the first electrode, and the semiconductor substrate and the first semiconductor for forming a PN junction. and the second electrode or the second electrode semiconductor region, a first horizontal photodiode is configured, and the first vertical photodiode and the first
1. A semiconductor photodetecting device comprising second bias power supply means for supplying separate bias power supplies to each of the horizontal photodiodes. 4 A semiconductor substrate having a second conductivity type opposite to the first conductivity type formed from the first main surface side to form a first PN junction in a semiconductor substrate having a first conductivity type. a first PN junction forming semiconductor region; in the semiconductor substrate, from the first main surface side;
a second PN junction forming semiconductor region having a second conductivity type formed to form a second PN junction; and a second main surface side opposite to the first main surface of the semiconductor substrate. a first electrode semiconductor region having a first electrode or a first conductivity type; and a second electrode or having a first conductivity type formed on the first main surface side of the semiconductor substrate. a second electrode semiconductor region, and includes the semiconductor substrate, the first PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; a second vertical photodiode is configured including the semiconductor substrate, the second PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; A first lateral photodiode is configured including a semiconductor substrate, the first PN junction forming semiconductor region, and the second electrode or the second electrode semiconductor region; A semiconductor photodetection device characterized in that a second lateral photodiode is configured including a semiconductor region for forming a PN junction and the second electrode or the semiconductor region for the second electrode. 5 A semiconductor substrate having a second conductivity type opposite to the first conductivity type formed from the first main surface side to form a first PN junction in a semiconductor substrate having a first conductivity type. a first PN junction forming semiconductor region; in the semiconductor substrate, from the first main surface side;
a second PN junction forming semiconductor region having a second conductivity type formed to form a second PN junction; and a second main surface side opposite to the first main surface of the semiconductor substrate. a first electrode semiconductor region having a first electrode or a first conductivity type; and a second electrode or having a first conductivity type formed on the first main surface side of the semiconductor substrate. a second electrode semiconductor region, and includes the semiconductor substrate, the first PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; a second vertical photodiode is configured including the semiconductor substrate, the second PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; A first lateral photodiode is configured including a semiconductor substrate, the first PN junction forming semiconductor region, and the second electrode or the second electrode semiconductor region; A second horizontal photodiode is configured including a semiconductor region for forming a PN junction and the second electrode or a semiconductor region for the second electrode, and the first and second vertical photodiodes are each biased separately. A semiconductor photodetection device characterized by having a third bias power supply means for supplying power. 6 A semiconductor substrate having a second conductivity type opposite to the first conductivity type formed from the first principal surface side to form a first PN junction in a semiconductor substrate having a first conductivity type. a first PN junction forming semiconductor region; in the semiconductor substrate, from the first main surface side;
a second PN junction forming semiconductor region having a second conductivity type formed to form a second PN junction; and a second main surface side opposite to the first main surface of the semiconductor substrate. a first electrode semiconductor region having a first electrode or a first conductivity type; and a second electrode or having a first conductivity type formed on the first main surface side of the semiconductor substrate. a second electrode semiconductor region, and includes the semiconductor substrate, the first PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; a second vertical photodiode is configured including the semiconductor substrate, the second PN junction forming semiconductor region, and the first electrode or the first electrode semiconductor region; A first lateral photodiode is configured including a semiconductor substrate, the first PN junction forming semiconductor region, and the second electrode or the second electrode semiconductor region; A second horizontal photodiode is configured including a semiconductor region for forming a PN junction and the second electrode or a semiconductor region for the second electrode, and the first and second vertical photodiodes and the first and a fourth bias power supply means for individually supplying bias power to each of the second horizontal photodiodes.