JP2020024228A - Light detecting device and electronic apparatus - Google Patents

Abstract

To provide a light detecting device capable of reducing the sensitivity in the infrared wavelength region well, and to provide an electronic apparatus including the same.SOLUTION: A light detecting device includes a semiconductor substrate, a light receiving section B1 for signal detection and an infrared ray receiving section B2 formed on the semiconductor substrate, and covered at least with a blue filter of common color, and a red filter superposed on the blue filter above the infrared ray receiving section B2, and capable of blocking the blue light passing through the blue filter. An output signal (information) close to the actual visible light component of incident light is obtained by excluding or attenuating (B1-B2) the infrared wavelength region selectively from the output signal of the light receiving section B1 for signal detection, on the basis of the magnitude of the output signal from the infrared ray receiving section B2.SELECTED DRAWING: Figure 6A

Description

  The present invention relates to a light detection device including a color filter and an electronic device including the same.

Conventionally, an infrared cut filter has been used to separate infrared light of light incident on a color sensor.
For example, Patent Document 1 discloses an optoelectronic sensor including a substrate having a plurality of sensors, an infrared cut filter that covers the sensors on the substrate, and a visible light filter on the infrared cut filter. This infrared cut filter is composed of, for example, a multilayer film formed by laminating about 50 dielectric films.

U.S. Pat. No. 8,274,051

However, the multilayer infrared cut filter has a problem that it is difficult to completely separate infrared rays of light obliquely incident because the infrared cut filter is designed on the assumption that light is incident perpendicularly on the filter.
One embodiment of the present invention provides a photodetector capable of favorably reducing the sensitivity in the infrared wavelength range.

  One embodiment of the present invention provides an electronic apparatus including a photodetector capable of favorably reducing sensitivity in a wavelength region of infrared light.

One embodiment of the present invention provides a semiconductor substrate, a signal detection light receiving unit and an infrared light receiving unit formed on the semiconductor substrate and covered by at least a color filter of a common color, and the color filter on the infrared light receiving unit. And a second color filter that overlaps and is capable of blocking light in a wavelength range that passes through the color filter.
According to this configuration, of the signal detection light receiving unit and the infrared light receiving unit covered with the color filter of the common color, only the infrared light receiving unit is selectively covered with the second color filter. Thus, when the same light is incident on the signal detection light-receiving unit and the infrared light reception unit, the signal detection light-receiving unit detects visible light and infrared light in a predetermined wavelength range, while the infrared light reception unit emits visible light. It can be selectively blocked by the second color filter, and can detect only infrared rays of the same level as the infrared rays detected by the signal detection light-receiving unit. Therefore, by a logic circuit or the like provided inside or outside the photodetector, the wavelength range of the infrared light from the output signal of the signal detection light-receiving unit can be selectively selected based on the magnitude of the output signal of the infrared light-receiving unit. By eliminating or attenuating, an output signal (information) close to the actual visible light component of the incident light can be obtained. Therefore, with the use of the photodetector according to the embodiment of the present invention, it is possible to accurately calculate the illuminance and the color temperature with a small error.

In such signal separation processing, only signals in the infrared wavelength range are digitally separated by a logical operation, so that the sensitivity in the infrared wavelength range is favorably reduced regardless of the incident direction of light. can do.
In one embodiment of the present invention, the signal detection light-receiving unit and the infrared light-receiving unit are respectively located at a first pn junction located at the same depth from the surface of the semiconductor substrate, and at a position deeper than the first pn junction. And a second pn junction portion.

There is a relationship that the depth of light transmission through a semiconductor substrate increases as the wavelength increases. Therefore, light can be efficiently detected by properly using the pn junction according to the wavelength of the light to be detected.
In one embodiment, the color filter includes a blue filter or a green filter, and the second color filter includes a red filter.

  The spectral sensitivity curve of light transmitted through the blue filter or the green filter has independent peaks in each of the blue or green wavelength range and the infrared wavelength range. Therefore, if a mountain-shaped curve having a peak in the blue or green wavelength region is separated from the spectral sensitivity curve in which these peaks appear, the mountain-shaped curve that can be considered to be derived from infrared rays will remain clearly. That is, according to this configuration, the infrared light can be easily determined by separating the light in the blue or green wavelength range by the red filter in the infrared light receiving unit.

  In one embodiment of the present invention, the color filter includes a red filter, and the second color filter includes a blue filter or a green filter. In this case, the signal detection light receiving unit and the infrared light receiving unit are respectively a first pn junction at the same depth position from the surface of the semiconductor substrate and a second pn junction at a position deeper than the first pn junction. It is preferable to include a part.

  Unlike the light that passes through the blue or green filter as described above, the spectral sensitivity curve of the light that passes through the red filter does not have distinctly independent peaks in each of the red and infrared wavelength ranges. is not. Therefore, it is difficult to selectively discriminate infrared light by a method of simply separating red light using a blue filter or a green filter in the infrared light receiving unit. Therefore, according to this configuration, the relationship is used that the longer the wavelength of light, the deeper the transmission depth in the semiconductor substrate. That is, the signal detection light-receiving portion mainly detects red light at the first pn junction, which is formed at a relatively shallow position and is suitable for detecting red light having a shorter wavelength than infrared light. On the other hand, in the infrared light receiving unit, the infrared light can be detected at the second pn junction, which is located at a relatively deep position and is suitable for detecting infrared light having a longer wavelength than red light. This makes it easier to selectively distinguish infrared light.

In one embodiment of the present invention, the signal detection light-receiving units are provided at positions that are point-symmetric with respect to a center of a light-receiving region on the semiconductor substrate.
According to this configuration, even if sufficient light does not enter one of the signal detection light receiving units because light does not uniformly hit the entire light receiving region of the semiconductor substrate, the other signal detection light receiving unit receives light. Can be detected, so the reliability is good.

One embodiment of the present invention further includes an infrared cut filter that covers the signal detection light receiving unit and the infrared light receiving unit.
According to this configuration, the sensitivity in the infrared wavelength region can be reduced more reliably.
In one embodiment of the present invention, the color filter includes a color resist.
One embodiment of the present invention provides a semiconductor substrate, a signal detection light receiving unit and an infrared light receiving unit formed on the semiconductor substrate and covered by at least a color filter of a common color, and the color filter on the infrared light receiving unit. Provided is an electronic apparatus including: a photodetector; and a housing accommodating the photodetector, wherein the photodetector includes a second color filter that overlaps and can block light in a wavelength range that passes through the color filter.

  According to this configuration, since the photodetector capable of satisfactorily reducing the sensitivity in the infrared wavelength region is provided, it is practical even if the visible light transmittance of the light receiving window formed in the electronic device is low. Therefore, the degree of freedom in designing the light receiving window can be increased.

FIG. 1 is a block diagram illustrating an electrical configuration of a photodetector according to an embodiment of the present invention. FIG. 2 is a layout diagram of a light receiving area of the photodetector. FIG. 3 is a cross-sectional view (a cross-sectional view along the line AA ′ in FIG. 2) of the photodetector. FIG. 4 is a cross-sectional view (a cross-sectional view taken along line BB ′ in FIG. 2) of the photodetector. FIG. 5 is an enlarged view of the photodiode of FIGS. 3 and 4. FIG. 6A is a diagram for describing calculation of infrared separation in the blue light receiving unit. FIG. 6B is a diagram illustrating a final spectral sensitivity characteristic in the blue light receiving unit. FIG. 7A is a diagram for explaining the calculation of infrared separation in the green light receiving unit. FIG. 7B is a diagram illustrating a final spectral sensitivity characteristic in the green light receiving unit. FIG. 8A is a diagram for explaining the calculation of infrared separation in the red light receiving unit. FIG. 8B is a diagram illustrating a final spectral sensitivity characteristic in the red light receiving unit. FIG. 9 is a diagram showing a final spectral sensitivity characteristic of the photodetector. FIG. 10 is a perspective view showing an external appearance of a smartphone, which is an example of an electronic device using the light detection device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an electrical configuration of a photodetector 1 according to one embodiment of the present invention.
The light detection device 1 includes a red light receiving unit 2R, a green light receiving unit 2G, and a blue light receiving unit 2B, an infrared cut filter 3 that covers these light receiving units 2R, 2G, and 2B, and a calculation unit 4.

  The red light receiving unit 2R, the green light receiving unit 2G, and the blue light receiving unit 2B have photodiodes 5R, 5G, and 5B, respectively. The photodiodes 5R, 5G, 5B are each electrically connected to the operation unit 4. An ADC (analog-to-digital converter) 6 is interposed between the photodiodes 5R, 5G, 5B and the arithmetic unit 4. When light enters the pn junction of each of the photodiodes 5R, 5G, and 5B, a current is generated by the photovoltaic effect, and the current is converted from an analog signal to a digital signal by the ADC 6 and input to the arithmetic unit 4. The arithmetic unit 4 performs an arithmetic process based on the input signal.

  The arithmetic unit 4 is formed of an integrated circuit such as an LSI (Large Scale Integration), and includes various circuit elements such as transistors, capacitors, and registers. The operation unit 4 is electrically connected to a plurality of external electrodes 7 formed on the outermost surface of the light detection device 1. Through the plurality of external electrodes 7, signal output from the arithmetic unit 4, power input to the arithmetic unit 4 and the photodiodes 5R, 5G, and 5B are performed.

FIG. 2 is a layout diagram of the light receiving region 9 of the light detection device 1.
The light detection device 1 has a semiconductor substrate 8 and a light receiving region 9 on the semiconductor substrate 8. Each of the red light receiving section 2R, the green light receiving section 2G, and the blue light receiving section 2B has a plurality of light receiving sections, which are arranged in the light receiving area 9.
Specifically, the red light receiving section 2R includes a signal detecting light receiving section R1 and infrared light receiving sections R2 and R3, the green light receiving section 2G includes a signal detecting light receiving section G1 and an infrared light receiving section G2, and the blue light receiving section 2B includes It includes a signal detection light receiving portion B1 and an infrared light receiving portion B2. A plurality of signal detection light receiving units R1, G1, B1 and a plurality of infrared light receiving units R2, R3, G2, B2 are provided. Of these light receiving units, at least a plurality of signal detection light receiving units R1, G1, and B1 are respectively located at point-symmetric positions with respect to the center C (center of gravity) of the light receiving region 9 having a rectangular shape in plan view. Is provided. Similarly, the plurality of infrared light receiving units R2, R3, G2, and B2 may be provided at point-symmetric positions as shown in FIG. Accordingly, even if sufficient light does not enter one of the signal detection light receiving portions R1, G1, and B1 because light does not uniformly hit the entire light receiving region 9 of the semiconductor substrate 8, the other signal detection Since light can be detected by the light receiving units R1, G1, and B1, reliability is high. For example, even if the light incident on the lower edge of the light receiving region 9 on the paper is poor, and the signal detection light receiving units R1 and B1 on the edge do not detect the light well, even if the light is not detected well, Light can be detected by the signal detection light receiving units R1 and B1 on the edge.

In FIG. 2, for the sake of clarity, reference numerals for the red light receiving unit 2R, the green light receiving unit 2G, and the blue light receiving unit 2B are omitted, and the light detecting units R1, G1, and B1 for signal detection are indicated by white squares. , The infrared light receiving units R2, R3, G2, and B2 are indicated by cross-hatched squares.
A clear light receiving portion 10 capable of receiving visible light and infrared light is formed at a corner of the light receiving region 9 having a rectangular shape in a plan view. For example, the clear light receiving units 10 may be arranged at least at corners forming a pair of diagonals of the light receiving region 9 in a plan view. The clear light receiving unit 10 includes a photodiode and is not covered with the infrared cut filter 3.

Next, the sectional structures of the signal detection light receiving units R1, G1, B1 and the infrared light receiving units R2, R3, G2, B2 will be described with reference to FIGS.
FIG. 3 is a cross-sectional view (a cross-sectional view along line AA ′ in FIG. 2) of the photodetector 1. FIG. 4 is a cross-sectional view (a cross-sectional view taken along line BB ′ of FIG. 2) of the photodetector 1. FIG. 5 is an enlarged view of the photodiode of FIGS. 3 and 4.

  The signal detection light receiving units R1, G1, B1 and the infrared light receiving units R2, R3, G2, B2 are common elements such as a semiconductor substrate 8, a photodiode 11 formed on the semiconductor substrate 8, and a semiconductor substrate 8. And an interlayer insulating film 12 covering the entire surface of the substrate. Although the photodiode 11 corresponds to each of the photodiodes 5R, 5G, and 5B in FIG. 1, reference numerals of the photodiodes 5R, 5G, and 5B are omitted in FIGS. I do.

In this embodiment, the semiconductor substrate 8 is formed of a p-type silicon substrate.
The photodiode 11 has an npnp structure including a first n-type region 13, a first p-type region 14, a second n-type region 15, and a p-type semiconductor substrate 8 formed in order from the surface 8 </ b> A of the p-type semiconductor substrate 8. are doing. A second n-type region 15 is formed on the surface of the p-type semiconductor substrate 8, a first p-type region 14 is formed in an inner region of the second n-type region 15, and a second p-type region 14 is formed in an inner region of the first p-type region 14. 1n type region 13 is formed. Thereby, as shown in FIG. 5, the photodiode 11 has a photo Di1, a photo Di2, and a photo Di3 including pn junctions having different depths from the surface 8A of the semiconductor substrate 8.

  Photo Di1 includes a pn junction between first p-type region 14 and first n-type region 13, and the depth of the pn junction from surface 8A is, for example, 0.09 μm to 0.17 μm. The photo Di2 includes a pn junction between the first p-type region 14 and the second n-type region 15, and the depth of the pn junction from the surface 8A is deeper than the pn junction of the photo Di1. 0 μm to 1.8 μm. The photo Di3 includes a pn junction between the p-type semiconductor substrate 8 and the second n-type region 15, and the depth of the pn junction from the surface 8A is deeper than the pn junction of the photo Di2. 0.2 μm to 5.9 μm.

  The advantages of the photodiode 11 having the photos Di1 to Di3 having different depths are as follows. That is, for a silicon substrate, the longer the wavelength of light, the longer the transmission depth tends to be. If there are a plurality of wavelength ranges of light components to be detected as in the photodetection device 1, the photo Di1 Light can be detected efficiently in any of Di3. For example, the photo Di1 is suitable for detecting components in a blue wavelength range (for example, 420 nm to 480 nm) and a green wavelength range (for example, 500 nm to 560 nm), and the photo Di2 is suitable for detecting a green wavelength range and a red wavelength range (for example. For example, it is suitable for detecting a component of 590 nm to 680 nm). Further, the photo Di3 is suitable for detecting a component in a wavelength region of infrared rays (for example, 700 nm to 1300 nm).

  Note that, in addition to the photodiode 11, for example, an impurity region of a transistor included in the arithmetic unit 4 may be formed in the semiconductor substrate 8. In this case, the first n-type region 13, the first p-type region 14, and the second n-type region 15 are composed of a source region (S), a drain region (D), and a buried layer (L / I, B / L) may be formed in the same step as the impurity region.

The interlayer insulating film 12 is made of an insulating material such as silicon oxide (SiO ₂ ). The interlayer insulating film 12 may be a single layer as shown in FIGS. 3 and 4, or may be a plurality of layers.
A red filter 16R, a green filter 16G, and a blue filter 16B are formed on the interlayer insulating film 12, and an infrared cut filter 3 is formed so as to cover these filters 16R, 16G, and 16B. The infrared cut filter 3 may be formed of, for example, a multilayer dielectric film in which a plurality of (for example, about 50) SiO ₂ / TiO ₂ structures are stacked. The infrared cut filter 3 is a coating film common to all the signal detection light receiving units R1, G1, B1 and the infrared light receiving units R2, R3, G2, B2. In addition, the red filter 16R, the green filter 16G, and the blue filter 16B can be composed of, for example, a color resist based on a pigment, a transmission resist formed using a nanoimprint technique, a gelatin film, or the like.

  Whether or not the red filter 16R, the green filter 16G, and the blue filter 16B are provided depending on the type of the light receiving unit thereunder, a light receiving unit for detecting light of the same color includes a color filter of a common color. Is always provided. That is, the red light filter 16R is always provided in the red signal detection light receiving portion R1 and the infrared light receiving portions R2 and R3, and the green filter 16G and the signal detection light receiving portion B1 in the signal detection light receiving portion G1 and the infrared light receiving portion G2. The same applies to the blue filter 16B in the infrared light receiving section B2.

  More specifically, the arrangement of the color filters 16R, 16G, and 16B will be described. A single layer film of the red filter 16R is provided in the signal detection light receiving unit R1, and a single layer film of the red filter 16R is provided in the infrared light receiving unit R2. Is provided, and a laminated film (16R is on the upper side) of the red filter 16R and the green filter 16G is provided in the infrared receiving section R3. The signal detection light-receiving portion G1 is provided with a single-layer film of a green filter 16G, and the infrared light-receiving portion G2 is provided with a laminated film of a red filter 16R and a green filter 16G (16R is on the upper side). Further, the signal detection light receiving portion B1 is provided with a single layer film of the blue filter 16B, and the infrared light receiving portion B2 is provided with a laminated film of the red filter 16R and the blue filter 16B (16R is on the upper side).

Next, spectral sensitivity characteristics obtained by calculation of infrared separation in the red light receiving unit 2R, the green light receiving unit 2G, and the blue light receiving unit 2B will be individually described.
(1) Blue (Blue) Characteristics Regarding the blue light receiving portion 2B, first, when light enters the signal detecting light receiving portion B1 and the infrared light receiving portion B2, the blue light and the infrared light are detected in the photo Di1 of the signal detecting light receiving portion B1. Is detected. On the other hand, in the photo Di1 of the infrared light receiving unit B2, blue light is selectively blocked by the red filter 16R, and only infrared light of the same level as the infrared light detected by the signal detecting light receiving unit B1 is detected. The spectral sensitivity characteristic at that time is shown by a curve in the left end and the middle of FIG. 6A. The arithmetic unit 4 receives a signal having a magnitude corresponding to the detection of blue light and infrared light from the signal detection light-receiving unit B1, and a signal having a magnitude corresponding to detection of infrared light from the infrared light-receiving unit B2. . Then, by selectively excluding or attenuating the infrared wavelength range component from the output signal of the signal detection light receiving portion B1 based on the magnitude of the output signal of the infrared light receiving portion B2 (B1-B2), the incident light is reduced. An output signal (information) close to the actual blue light component is obtained. The spectral sensitivity characteristic obtained by this signal classification processing is represented by a curve as shown in the right end of FIG. 6A. In this embodiment, since a part of the infrared light is further filtered (separated) by the infrared cut filter 3, a spectral sensitivity curve as shown in FIG. 6B is finally obtained.

As is clear from FIG. 6A, the spectral sensitivity curve of light transmitted through the single-layer film of the blue filter 16B in the signal detection light-receiving portion B1 has independent peaks in the blue wavelength region and the infrared wavelength region, respectively. Have. Therefore, if the peak-shaped curve having a peak in the blue wavelength region is separated from the spectral sensitivity curve in which these peaks appear, the peak-shaped curve that may be considered to be derived from infrared rays will remain clearly. That is, according to this embodiment, the infrared light receiving unit B2 separates the light in the blue wavelength range with the red filter 16R, and as shown by the spectral sensitivity curve of the infrared light receiving unit B2 in FIG. It can be easily determined.
(2) Green (Green) Characteristics Regarding the green light receiving portion 2G, first, when light enters the signal detecting light receiving portion G1 and the infrared light receiving portion G2, the green light appears in the photo Di1 and the photo Di2 of the signal detecting light receiving portion G1. Light and infrared are detected. On the other hand, in the photo Di1 and the photo Di2 of the infrared light receiving unit G2, green light is selectively blocked by the red filter 16R, and only infrared light of the same level as the infrared light detected by the signal detection light receiving unit G1 is detected. The spectral sensitivity characteristic at that time is shown by a curve in the left end and the middle of FIG. 7A. The arithmetic unit 4 receives a signal having a magnitude corresponding to the detection of green light and infrared light from the signal detection light-receiving unit G1, and a signal having a magnitude corresponding to detection of infrared light from the infrared light-receiving unit G2. . Then, by selectively removing or attenuating the wavelength range of the infrared ray from the output signal of the signal detection light receiving section G1 based on the magnitude of the output signal of the infrared light receiving section G2 (G1-G2), the incident light is reduced. An output signal (information) close to the actual green light component is obtained. The spectral sensitivity characteristic obtained by this signal classification processing is represented by a curve as shown in the right end of FIG. 7A. In this embodiment, since a part of the infrared light is also filtered (separated) by the infrared cut filter 3, a spectral sensitivity curve as shown in FIG. 7B is finally obtained.

As is clear from FIG. 7A, the spectral sensitivity curve of the light transmitted through the single-layer film of the green filter 16G in the signal detection light-receiving portion G1 has independent peaks in the green wavelength region and the infrared wavelength region, respectively. Have. Therefore, if the peak-shaped curve having a peak in the green wavelength region is separated from the spectral sensitivity curve in which these peaks appear, the peak-shaped curve that may be regarded as being derived from infrared rays will remain clearly. That is, according to this embodiment, the infrared light receiving unit G2 separates the light in the green wavelength range by the red filter 16R, thereby reducing the infrared light as shown by the spectral sensitivity curve of the infrared light receiving unit G2 in FIG. 7A. It can be easily determined.
(3) Red (Red) Characteristics On the other hand, the red light receiving unit 2R is different from the blue light receiving unit 2B and the green light receiving unit 2G described above, and as shown at the left end of FIG. In the above, the spectral sensitivity curve of the light transmitted through the single-layer film of the red filter 16R does not have clearly independent peaks in each of the red wavelength region and the infrared wavelength region. Therefore, it is difficult to selectively distinguish infrared light by a method of simply separating red light using the blue filter 16B or the green filter 16G in the infrared light receiving units R2 and R3. Therefore, this embodiment utilizes the relationship that the longer the wavelength of light, the deeper the transmission depth in the semiconductor substrate 8.

That is, as shown in FIG. 8A, in the signal detection light receiving unit R1, mainly red light is detected by the photo Di2 formed at a relatively shallow position. By detecting with the photo Di2, red light having a shorter wavelength than infrared light can be detected favorably.
On the other hand, the infrared light receiving units R2 and R3 create spectral characteristics close to the infrared band of the signal detection light receiving unit R1. Specifically, red light and infrared light are detected by the photo Di3 of the infrared light receiving unit R2. On the other hand, in the photo Di3 of the infrared light receiving portion R3, red light is selectively blocked by the green filter 16G, and only infrared light of the same level as the infrared light detected by the signal detecting light receiving portion R1 is detected. In order to detect infrared rays at the same level as the infrared rays of the signal detection light receiving unit R1, the area of the infrared light receiving unit R3 is made slightly smaller (about 10 to 20%) than that of the infrared light receiving unit R2, and the material of the color filter is changed. Enabled by: Then, by selectively removing or attenuating the infrared wavelength range component from the output signal of the signal detection light receiving unit R1 based on information obtained by the combination of the infrared light receiving unit R2 and the infrared light receiving unit R3 (R1- (R2-R3)), an output signal (information) close to the actual red light component of the incident light is obtained. A spectral sensitivity characteristic obtained by this signal classification processing is shown by a curve in the lower part of FIG. 8A. In this embodiment, a part of the infrared light is further filtered (separated) by the infrared cut filter 3, so that a spectral sensitivity curve as shown in FIG. 8B is finally obtained.

  As described above, the sensitivity in the infrared wavelength range in each of the light receiving units 2R, 2G, and 2B is reduced by the above arithmetic processing, so that the spectral sensitivity characteristics of the photodetector 1 shown in FIG. As is clear from FIG. 9, the sensitivity in the infrared wavelength region can be reduced to a value close to zero. Therefore, with the use of the photodetector 1 according to the embodiment of the present invention, it is possible to accurately calculate the illuminance and the color temperature with a small error.

The light detection device 1 can be applied to an optical sensor having a plurality of optical filters, such as an illuminance sensor and a proximity sensor, in addition to a color sensor. Furthermore, these optical sensors can be mounted on, for example, smartphones, mobile phones, digital cameras, car navigation systems, notebook computers, tablet PCs, and the like.
Specifically, a form when applied to a smartphone is shown below.

FIG. 10 is a perspective view illustrating an external appearance of a smartphone 21 which is an example of an electronic device using the light detection device 1.
The smartphone 21 is configured by housing electronic components inside a flat rectangular parallelepiped housing 22. The housing 22 has a pair of rectangular main surfaces on the front side and the back side, and the pair of main surfaces is connected by four side surfaces. A display surface of a display panel 23 composed of a liquid crystal panel, an organic EL panel, or the like is exposed on one main surface of the housing 22. The display surface of the display panel 23 constitutes a touch panel, and provides an input interface for a user.

  The display panel 23 is formed in a rectangular shape that occupies most of one main surface of the housing 22. The operation buttons 24 are arranged along one short side of the display panel 23. In this embodiment, a plurality (three) of operation buttons 24 are arranged along a short side of the display panel 23. By operating the operation buttons 24 and the touch panel, the user can operate the smartphone 21 to call and execute necessary functions.

  In the vicinity of another short side of the display panel 23, a speaker 25 is arranged. The speaker 25 provides an earpiece for a telephone function and is also used as an acoustic unit for reproducing music data and the like. A lens window 26 is arranged next to the speaker 25. The light detection device 1 is arranged in the housing 22 so as to face the lens window 26. On the other hand, near the operation button 24, a microphone 27 is arranged on one side surface of the housing 22. The microphone 27 provides a mouthpiece for a telephone function, and can also be used as a microphone for recording.

Since the smartphone 21 includes the photodetector 1 that can satisfactorily reduce the sensitivity in the infrared wavelength range, the smartphone 21 is practically usable even when the visible light transmittance of the lens window 26 for light reception formed on the smartphone 21 is low. is there. Therefore, the degree of freedom of the design of the lens window 26 (change of color and shape, etc.) can be increased.
The embodiments of the present invention have been described above, but the present invention can be embodied in other forms.

For example, in the above-described embodiment, the calculation unit 4 is provided as a part of the light detection device 1. However, the signal classification processing by the calculation unit 4 is performed by a logic circuit (such as an electronic device) outside the light detection device 1. CPU or the like).
In addition, various design changes can be made within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Photodetector 2R, 2G, 2B Light receiving part 3 Infrared cut filter 4 Operation part 5R, 5G, 5B Photodiode 6 ADC
Reference Signs List 7 external electrode 8 semiconductor substrate 8A surface 9 light receiving area 10 clear light receiving section 11 photodiode 12 interlayer insulating film 13 first n-type area 14 first p-type area 15 second n-type area 16R red filter 16G green filter 16B blue filter Di1 photodiode Di2 Photodiode Di3 Photodiode R1, G1, B1 Signal detection light receiving unit R2, R3, G2, B2 Infrared light receiving unit

Claims (15)

A semiconductor substrate;
A first light receiving unit formed on the semiconductor substrate and covered with a first filter of a first color;
A second light receiving unit that is covered with the first filter and is adjacent to the first light receiving unit;
A third light receiving unit that is covered with a second filter of a second color and is adjacent to the first light receiving unit;
A photodetector, comprising: a fourth light receiving unit which is covered with the third filter of the second color and is adjacent to the first light receiving unit.   The light detection device according to claim 1, further comprising a fifth light receiving unit that is covered with a fourth filter of a third color and is adjacent to the first light receiving unit.   The photodetector according to claim 2, further comprising a sixth light receiving unit that is covered with the fourth filter and is adjacent to the fifth light receiving unit.   The light detection device according to claim 1, further comprising a seventh light receiving unit that is covered with the second filter and is adjacent to the fourth light receiving unit.   With the center of the light receiving region on the semiconductor substrate as the center of the object, the first light receiving unit and the second light receiving unit are located at positions that are point-symmetric with respect to the third light receiving unit and the fourth light receiving unit, respectively. The photodetector according to claim 1, wherein the photodetector is formed.   The light detection device according to claim 1, wherein the first color is green, and the second color is red.   The photodetector according to claim 2, wherein the third color is blue.   The photodetector according to any one of claims 1 to 7, wherein the third light receiving unit is formed between the first light receiving unit and the second light receiving unit.   The light detection device according to any one of claims 1 to 8, wherein the first light receiving unit, the second light receiving unit, the third light receiving unit, and the fourth light receiving unit are covered with an infrared cut filter. .   The light detection device according to claim 5, further comprising a clear light receiving unit disposed at at least one corner of the light receiving area and capable of receiving visible light and infrared light. A semiconductor substrate;
A first light receiving unit formed on the semiconductor substrate and covered with a first filter of a first color;
A second light receiving unit covered with the first filter and adjacent to the first light receiving unit in a first direction;
And a third light receiving unit that is covered with the second filter of the first color and is adjacent to the first light receiving unit in a second direction.   The photodetector according to claim 11, wherein the first filter covers a third filter of a second color different from the first color on the first light receiving unit.   The first light receiving unit, the second light receiving unit, and the third light receiving unit are electrically connected to the third light receiving unit based on information obtained by the first light receiving unit and the second light receiving unit. The photodetector according to claim 12, further comprising a calculation unit that selectively removes or attenuates infrared wavelength components from the output signal.   The photodetector according to any one of claims 11 to 13, wherein the first light receiving unit, the second light receiving unit, and the third light receiving unit are covered with an infrared cut filter. The light detection device according to any one of claims 1 to 14,
An electronic device, comprising: a housing accommodating the photodetector.

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