JP2002176192A - Illuminance sensor chip, illuminance sensor, equipment and method for measuring illuminance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for measuring the illuminance reflecting the quantity of visible light advantageously from the view point of cost. SOLUTION: The illuminance sensor chip comprises a first semiconductor layer, and a second semiconductor layer joining with the first semiconductor layer. When light impinges on the joining part of the first and second semiconductor layers through the second semiconductor layer, the illuminance sensor chip outputs an electric signal corresponding to the quantity of light impinging on the joining part. Thickness of the second semiconductor layer is set at 2-4 μm, for example, so that the peak sensitivity wavelength in the spectral sensitivity characteristics with reference to the output level of the electric signal falls within the wavelength range of visible light (e.g. 580-600 nm). The second semiconductor layer is constituted as silicon semiconductor and the illuminance sensor is constituted as a phototransistor having an npn junction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminance sensor chip used for detecting ambient brightness and a technique related thereto.

[0002]

2. Description of the Related Art Illuminance sensors are used to detect ambient brightness, and have been used for various purposes. For example, in a camera, it is determined whether or not to fire a flash based on an output from an illuminance sensor.

An illuminance sensor has an illuminance sensor chip configured as, for example, a phototransistor or the like. The illuminance sensor chip outputs an electric signal according to the amount of received light. An illuminance sensor chip conventionally used has a peak sensitivity wavelength of 800 to 950 n in spectral sensitivity characteristics (showing the relationship between wavelength and output).
m. This illuminance sensor chip outputs an electric signal mainly corresponding to the amount of infrared light received. That is, the illuminance sensor including the illuminance sensor chip outputs an electric signal correlated with ambient brightness based on the amount of infrared light.

[0004] In a mobile phone, an image is displayed using, for example, a reflection type liquid crystal display device. In a reflective liquid crystal display device, the brightness of a display screen is determined by the amount of visible light component of incident light. Therefore, if the periphery of the display device is sufficiently bright, image display can be performed only by external light, whereas if the periphery of the display device is dark, image display cannot be performed only by external light.
Therefore, in the liquid crystal display device, when the amount of external light is insufficient, it is necessary to turn on the light source to compensate for the amount of visible light.

[0005] In this case, it is conceivable to detect the brightness around the liquid crystal display device based on the output from the illuminance sensor and determine whether to turn on the light source according to the detection result.

As described above, the brightness of the display screen of a reflection type liquid crystal display device is determined by the amount of visible light component of incident light.
Therefore, ideally, it is necessary to grasp the brightness around the liquid crystal display device based on the amount of visible light and determine whether to turn on the light source. On the other hand, the conventional illuminance sensor chip has a peak sensitivity wavelength in the spectral sensitivity characteristic in an infrared region. On the other hand, the wavelength that a human perceives most in photopic vision (comparative peak wavelength) is about 555 nm,
This is greatly deviated from the peak sensitivity wavelength of the conventional illuminance sensor chip. Therefore, the conventional illuminance sensor is not appropriate as the illuminance sensor for the mobile phone described above. Therefore, there is a method of providing an infrared light cut filter in the illuminance sensor and selectively receiving visible light. However, it is not only technically difficult to cut off the infrared light without reducing the amount of visible light, but it is disadvantageous in terms of manufacturing cost by providing the infrared light cut filter.

The present invention has been conceived in view of the above circumstances, and provides a technique capable of measuring the illuminance reflecting the amount of visible light in an advantageous manner in terms of manufacturing cost.

[0008]

DISCLOSURE OF THE INVENTION In a first aspect of the present invention, a first semiconductor layer, a second semiconductor layer joined to the first semiconductor layer,
And when light is incident on the junction between the first semiconductor layer and the second semiconductor layer via the second semiconductor layer,
The second semiconductor layer is configured to output an electric signal according to the amount of light incident on the bonding portion, and the thickness of the second semiconductor layer is determined by a peak sensitivity wavelength in a spectral sensitivity characteristic based on the output amount of the electric signal. Is set to be in the wavelength range of visible light, thereby providing an illuminance sensor chip.

Preferably, the thickness of the second semiconductor layer is 4 μm or less. More preferably, the thickness of the second semiconductor layer is 2 μm or more.

[0010] In a preferred embodiment, the peak sensitivity wavelength is between 580 and 600 nm. The second semiconductor layer is configured as, for example, a silicon semiconductor.

[0011] In a preferred embodiment, the illuminance sensor chip is configured as a phototransistor. It is preferable that the phototransistor has an npn junction. In that case, the second semiconductor layer is configured as a P-type semiconductor layer.

According to a second aspect of the present invention, there is provided an illuminance sensor including the illuminance sensor chip according to the first aspect of the present invention.

In a preferred embodiment, the illuminance sensor has an additional illuminance sensor chip having the same or substantially the same spectral sensitivity characteristic as the illuminance sensor chip, and absorbs visible light with respect to the additional illuminance sensor chip. And a visible light cut section for receiving the incident light after that.

The additional illuminance sensor chip is sealed in, for example, a resin package colored black. In this case, the resin package forms the visible light cut section.

In a preferred embodiment, the illuminance sensor chip is sealed in a transparent first resin package,
The additional illuminance sensor chip is sealed in a second resin package colored black. In this case, the second resin package forms a visible light cut section.

It is preferable that the first resin package and the second resin package are sealed with a transparent third resin package.

The visible light cut section may be constituted by providing a visible light cut filter so as to cover the second semiconductor layer.

According to a third aspect of the present invention, there is provided a first semiconductor layer, a second semiconductor layer joined to the first semiconductor layer, and the first semiconductor layer and the second semiconductor layer. A first and a second illuminance sensor chip configured to output an electric signal according to the amount of light incident on the junction when light enters the junction with the second semiconductor layer via the second semiconductor layer; A visible light cut section for absorbing incident light and receiving incident light to the joint of the second illuminance sensor chip, based on outputs from the first and second illuminance sensors, An illuminance calculation unit for calculating illuminance, the illuminance measurement device being provided.

In a preferred embodiment, the second
This illuminance sensor chip has the same or substantially the same spectral sensitivity characteristics as the first illuminance sensor chip.

[0020] In a preferred embodiment, the illuminance calculation section includes an output from the first illuminance sensor chip,
The illuminance is calculated based on a signal corresponding to a difference from the output from the second illuminance sensor chip.

According to a fourth aspect of the present invention, there is provided a method for measuring illuminance by using first and second illuminance sensor chips, wherein the first and second illuminance sensor chips include a first semiconductor layer. And a second semiconductor layer joined to the first semiconductor layer, and light is incident on a junction between the first semiconductor layer and the second semiconductor layer via the second semiconductor layer. In this case, an electric signal corresponding to the amount of light incident on the joint is output, and the first signal is output.
And calculating the illuminance based on the output from the second illuminance sensor.

In a preferred embodiment, the first
The second illuminance sensor chip and the second illuminance sensor chip have the same or substantially the same spectral sensitivity characteristics, and the second illuminance sensor chip Is made incident.

In a preferred embodiment, the first
The illuminance is calculated based on a signal corresponding to a difference between the output from the illuminance sensor chip of the above and the output from the second illuminance sensor chip.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An illuminance measuring device X1 according to a first embodiment of the present invention shown in FIG. 1 is used, for example, by being incorporated in a mobile phone. In the mobile phone, it is determined whether to turn on the light source of the reflective liquid crystal display device based on the illuminance measured by the illuminance measurement device X1.

The illuminance measuring device X1 has an illuminance sensor 1 and an illuminance calculation unit 2. The illuminance sensor 1 is mainly configured to receive visible light.
As shown in FIGS. 1 and 2, the illuminance sensor 1 includes an insulating substrate 10, a first electrode 11, a second electrode 12, and a first illuminance sensor chip 13.

The insulating substrate 10 has a substantially rectangular plate shape made of an insulating material such as a glass epoxy resin.
The first and second electrodes 11 and 12 are connected from the upper surface 10a of the insulating substrate 10 to the lower surface 10c via the side surface 10b. The first and second electrodes 11 and 12 can be formed by forming a metal film (for example, an Al film) by, for example, vapor deposition and then performing an etching process.

The first electrode 11 has an illuminance sensor chip 13
Has been implemented. The illuminance sensor chip 13 is joined to the first electrode 11 via, for example, a conductive adhesive.
A wire 1 is provided between the second electrode 12 and the illuminance sensor chip 13.
4. The wire 14 is made of, for example, a gold wire. The connection between the second electrode 12 and the illuminance sensor chip 13 by the wire 14 can be performed using, for example, an existing wire bonder.

Illuminance sensor chip 13 and wire 14
Are sealed by a resin package 15. The resin package 15 is transparently formed of, for example, epoxy resin so as to transmit visible light. Such a resin package 15 can be formed by, for example, a transfer molding method.

The illuminance sensor chip 13 has a peak sensitivity wavelength of the spectral sensitivity characteristic in a visible light wavelength range, for example, 380.
780 nm, more preferably 580-600 nm. The illuminance sensor chip 13
On N ⁺ type silicon substrate 30 as shown in FIG. 3, NP
It is configured as a phototransistor having an N junction 31 formed therein. On the lower surface 30b of the N ⁺ type silicon substrate 30, a collector electrode 32 is formed. The collector electrode 32 is formed of, for example, Au. The collector electrode 32 can be formed by vapor deposition or the like.

The NPN junction 31 includes an N ⁻ type semiconductor layer 33 as a first semiconductor layer, a P type semiconductor layer 34 as a second semiconductor layer, and an N ⁺ type semiconductor layer 35.

The N ⁻ type semiconductor layer 33 is a portion that functions as a collector, and is provided over the entire surface of the Si substrate 30.

The P-type semiconductor layer 34 is a portion that functions as a base, and is formed in the N ⁻ -type semiconductor layer 33. The thickness D of the P-type semiconductor layer 34 is set so that the peak sensitivity wavelength in the spectral sensitivity characteristic is in the range of visible light (see D = 3.2 μm in FIG. 4). In order to obtain such spectral sensitivity characteristics, the thickness D of the P-type semiconductor layer 34 is, for example, 2 to 4 μm,
Preferably, it is 2.5 to 3.5 μm. The relationship between the thickness D of the P-type semiconductor layer 34 and the peak sensitivity wavelength will be discussed later.

The N ⁺ type semiconductor layer 35 is a portion that functions as an emitter, and is considered to be built in the P type semiconductor layer 34.

The NPN junction 31 is formed in a wafer process for an N ⁺ type silicon wafer. In the wafer process, for example, a portion corresponding to the N ⁻ type semiconductor layer 33 is formed by vapor phase epitaxial growth, and portions corresponding to the P type semiconductor layer 34 and the N ⁺ type semiconductor layer 35 are formed by impurity diffusion. As a dopant for forming a portion corresponding to the P-type semiconductor layer 34, for example, boron is used. N ⁺ type semiconductor layer 3
As a dopant for forming a portion corresponding to 5,
For example, phosphorus is used.

Using B ₂ H ₆ (boron is boron) as an impurity source, the thickness D is 2 to 4 μm by impurity diffusion.
The diffusion conditions for forming the P-type semiconductor layer 34 of m are, for example, a heating temperature of 1100 to 1200 ° C. and a heating time of 90 to 90 ° C.
It is 110 minutes.

An insulating layer 36 is provided on the upper surface 31a of the NPN junction 31. The insulating layer 36 is formed so as to cover the boundary between the adjacent semiconductor layers 33, 34, 35 on the upper surface 31a. Therefore, most of the P-type semiconductor layer 34 and the N ⁺ -type semiconductor layer 35 are exposed via the insulating layer 36. The insulating layer 36 is formed of, for example, SiO ₂ .

The exposed surface 34a of the P-type semiconductor layer 34 is covered with a protective film 38. The protection film 38 is formed of, for example, SiN. On the other hand, the exposed surface 35a of the N ⁺ -type semiconductor layer 35 is covered by the emitter electrode 37. Emitter electrode 37 is formed of, for example, Al or the like.

In the illuminance sensor 1, when light enters the P-type semiconductor layer 34 of the illuminance sensor chip 13 via the resin package 15, an electric signal (emitter current) corresponding to the amount of received light is output. Carriers are injected by light incident on the P-type semiconductor layer 13 and a base current flows. Thus, the collector current is supplied to the N ⁻ type semiconductor layer 33. The collector current is supplied from an external power supply (not shown) connected to the first electrode 11 through the collector electrode 32. From the emitter electrode 37, the base current and the collector current are summed and output as an emitter current. The emitter current is input to the illuminance calculation unit 2 via the wire 14 and the first electrode 11.

The illuminance calculation section 2 calculates the illuminance based on the emitter current from the illuminance sensor 1. The illuminance calculation unit 2 can be configured by, for example, a CPU, a ROM, a RAM, and the like.

The ROM stores, for example, a table indicating the relationship between the emitter current and the illuminance and a program for calculating the illuminance based on the table. The CPU and the RAM execute a program using the emitter current as a variable, and calculate the illuminance according to the emitter current (the amount of received light).

The inventors of the present application examined spectral sensitivity characteristics of four illuminance sensor chips in which only the thickness D (see FIG. 3) of the P-type semiconductor layer 34 was different. FIG. 1 shows the spectral sensitivity characteristics.
And it measured as the form of the illuminance sensor as shown in FIG. The result is shown in FIG. Note that the P-type semiconductor layer was formed by diffusing boron as a dopant.

The thickness of the P-type semiconductor layer is
(Ω) at different depths from the upper surface 34a of the
It was determined by measuring the resistivity (Ωcm) and the carrier density (cm− ³ ). More specifically, the position where the absolute values of these values peak was determined as the thickness of the P-type semiconductor layer. FIG. 5 shows an example in which the resistance is a black triangle, the resistivity is a solid line, and the carrier density is a two-dot chain line. In this example, the thickness of the P-type semiconductor layer is 3.2 μm. As a result of such measurement, the thicknesses of the P-type semiconductor layers of the four illuminance sensor chips are 3.2 μm, 4.3 μm, and 4.9 μm, respectively.
m, and 5.1 μm.

As can be seen from FIG. 4, if the thickness of the P-type semiconductor layer is relatively small, the peak sensitivity wavelength falls within the wavelength range of visible light. As the thickness of the P-type semiconductor layer increases,
The peak sensitivity wavelength shifts to the longer wavelength side. This result means that by adjusting the thickness of the P-type semiconductor layer, the visible light sensitivity can be increased, and an illuminance sensor chip (illuminance sensor) having a peak sensitivity wavelength in the visible light range can be provided. In this experiment, as can be inferred from FIG.
It can be seen that the thickness of the P-type semiconductor layer should be 4 μm or less. Assuming that the thickness of the P-type semiconductor layer is 3, 2 μm, an illuminance sensor chip (illuminance sensor) having a peak sensitivity wavelength in the range of 580 to 600 nm is provided.

On the other hand, the lower limit of the thickness D of the P-type semiconductor layer 34
Is preferably 2 μm. Thickness of P-type semiconductor layer 34
If D is unduly small, an appropriate NPN junction is achieved
This is because it becomes difficult to do so. That is, impurity diffusion
N⁺When forming the type semiconductor layer 35
Is N if the thickness of the P-type semiconductor layer 34 is unduly reduced.
^-Without diffusing impurities into the p-type semiconductor layer 33,
It becomes difficult to diffuse impurities only into the semiconductor layer 34
Because.

As described above, in the illuminance sensor chip 13,
The thickness D of the P-type semiconductor layer 34 is adjusted so that the peak sensitivity wavelength is in the visible light range. Then, by setting the thickness D of the P-type semiconductor layer 34 to an appropriate value, the peak sensitivity wavelength can be made closer to the relative luminous efficiency peak wavelength in photopic vision. Therefore, in the illuminance sensor chip 13 (illuminance sensor 1), the output (emitter current) is increased or decreased in accordance with the human sense, in correlation with the human sense of brightness. As a result, the illuminance measuring device X1 measures the illuminance according to the sense of the human.

The illuminance sensor chip 13 includes the P-type semiconductor layer 3
By adjusting the thickness D of No. 4, the peak sensitivity wavelength is in the range of visible light, which is advantageous in terms of manufacturing cost. First, since an infrared light cut filter for setting the peak sensitivity wavelength in the visible light range is not required, the manufacturing cost is advantageous. Second, for example, P
When the p-type semiconductor layer 34 is formed,
Since the adjustment of the thickness D only requires adjusting the diffusion conditions, an existing production line can be used without changing the production line, which is advantageous in terms of production cost.

The illuminance measuring device X1 can be used to determine whether or not to turn on a light source of a reflection type liquid crystal display device used in a mobile phone or the like. As described above, the illuminance measuring device X1 measures the illuminance in accordance with the sense of a person. When people feel bright,
The display screen of the liquid crystal display device is bright, and the displayed image is easy to see. On the other hand, when a person feels dark, the display screen is dark and it is difficult to visually recognize the display image. Therefore, if the illuminance can be measured in accordance with the human sense, the light source can be turned on only in an environment where the displayed image is difficult to visually recognize. As a result, unnecessary lighting of the light source can be prevented and power consumption can be reduced Reduction can be achieved.

Next, an illuminance measuring device X2 according to a second embodiment of the present invention will be described with reference to FIGS.

The illuminance measuring device X2 has a first illuminance sensor 1, a second illuminance sensor 5, and an illuminance calculation unit 6. The first illuminance sensor 1 is the same as the illuminance sensor employed in the first embodiment of the present invention. Accordingly, the illuminance sensor 1 outputs an electric signal (emitter current) mainly corresponding to the amount of visible light received. The emitter current is input to the illuminance calculation unit 6 via the wire 14 and the second electrode 12. In FIG. 6, the first illumination sensor 1 and its components are denoted by the same reference numerals as those of the illumination sensor and its components in FIGS.

On the other hand, the second illuminance sensor 5 has the same basic configuration and operation as those of the first illuminance sensor 1. That is, the second illuminance sensor 5 includes the mounting board 50, the first and second electrodes 51 and 52, the illuminance sensor chip 53, the wires 54, and the resin package 55.

However, when the resin package 55 and visible light are selected.
It is configured to selectively absorb. More specifically
The resin package 55 is made of, for example, epoxy resin.
To black by adding black pigment
Have been. As a black pigment, Black iron oxide, CdTe,
And carbon black.

The second illuminance sensor chip 53 has the same or substantially the same spectral sensitivity characteristics as the illuminance sensor chip 13 (see D = 3.2 μm in FIG. 4). Is the same as

In the second illuminance sensor 5, an illuminance sensor chip 53 is sealed in a resin package 55 colored black. Therefore, visible light is absorbed by the resin package 55, and infrared light is selectively incident on the illuminance sensor chip 53. Therefore, the second illuminance sensor 5
As shown in FIG. 7, an electric signal (emitter current) corresponding to the amount of received infrared light is output. The emitter current is input to the illuminance calculation unit 6 via the wire 54 and the second electrode 52 (see FIG. 6).

In particular, since the second illuminance sensor 5 employs the illuminance sensor chip 53 having the same or substantially the same spectral sensitivity characteristics as the first illuminance sensor 1, as shown in FIG. The spectral sensitivity characteristic of the second illuminance sensor 5 substantially matches the spectral sensitivity characteristic of the first illuminance sensor 1 in an infrared light region.

The illuminance calculation unit 6 calculates the illuminance from the difference (the emitter current) from the output (emitter current) of the first illuminance sensor 1 and the output (emitter current) of the second illuminance sensor 5. . The illuminance calculation unit 6 includes, for example, a difference amplifier,
It can be configured by a CPU, a ROM, a RAM, and the like.

The difference amplifier outputs the difference between the emitter current from the first illuminance sensor 1 and the emitter current from the second illuminance sensor 5.

The CPU, ROM, and RAM calculate the illuminance based on the output from the difference amplifier.
The ROM stores, for example, a table indicating a relationship between the output and the illuminance, and a program for calculating the illuminance based on the table. The CPU and the RAM execute the program using the output from the difference amplifier as a variable, and calculate the illuminance according to the output.

In the illuminance measuring device X2, as described with reference to FIG. 7, the spectral sensitivity characteristic of the second illuminance sensor 5 substantially matches the spectral sensitivity characteristic of the first illuminance sensor 1 in the infrared light region. ing. Therefore, the difference between the emitter current of the first illuminance sensor 1 and the emitter current of the second illuminance sensor 5 substantially corresponds to the amount of visible light. Therefore, if the illuminance is calculated using the difference between the emitter currents of the first and second illuminance sensors 1 and 5, it is possible to measure the illuminance in accordance with a human sense.

In the illuminance sensor chip 53, a visible light cut filter may be provided so as to cover the P-type semiconductor layer (see FIG. 3). In that case, the resin package 55 may be configured to be transparent.

Next, an illuminance measuring device according to a third embodiment of the present invention will be described with reference to FIGS.

The illuminance measuring device X3 has one insulating substrate 70
In contrast, a sensor corresponding to the illuminance sensors 1 and 5 shown in FIG. In FIGS. 8 and 9, components corresponding to the components of the illuminance sensors 1 and 5 shown in FIG. 6 are denoted by the same reference numerals.

The first electrodes 11 and 51 and the second electrodes 12 and 52 are formed on the insulating substrate 70. First electrode 1
The illuminance sensor chips 13 and 53 are mounted on 1, 51, respectively. These illuminance sensor chips 13 and 53 have the same or substantially the same spectral sensitivity characteristics, and are preferably the same. The illuminance sensor chips 13 and 53
The second electrodes 12 and 52 are connected via wires 14 and 54.

Illuminance sensor chip 13 and wire 14
Are sealed by the first resin package 15. The illuminance sensor chip 53 and the wires 54 are sealed by a second resin package 55. The first resin package 15 is formed transparent, and the second resin package 55 is formed black, for example. First and second resin packages 1
5 and 55 are covered by the third resin package 71. The third resin package 71 is formed transparent.

The illuminance calculation unit 6 calculates the difference between the output of the illuminance sensor chip 13 and the output of the illuminance sensor chip 53 and calculates the illuminance from the difference. This illuminance calculation unit 6
Are, for example, difference amplifiers, CPUs, ROMs and RAs.
M or the like.

Since the illuminance measuring device X3 has the same basic configuration and operation as the illuminance measuring device X2, it can enjoy the same effects as the illuminance measuring device X2.

In the illuminance sensor 7, the illuminance sensor may be constructed by omitting the third resin package 71. In the illuminance sensor chip 53, a visible light cut filter may be provided so as to cover the P-type semiconductor layer (see FIG. 3). In that case, the resin package 55 may be configured to be transparent, or the illuminance sensor chips 13 and 53 may be sealed by one transparent resin package.

In the present invention, the illuminance sensor chip is
It may be configured as a photo transistor of a type. In that case, by adjusting the thickness of the N-type semiconductor layer, the peak sensitivity wavelength in the spectral sensitivity characteristic is formed so as to be in the visible light wavelength range.

The illuminance sensor chip may be configured as a photodiode. Also in this case, by adjusting the distance to the PN junction (corresponding to the thickness D of the P-type semiconductor layer 34 in FIG. 3), the peak sensitivity wavelength in the spectral sensitivity characteristics becomes in the visible light wavelength range. Formed.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a part of an illuminance measuring device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view of an illuminance sensor chip.

FIG. 4 is a graph showing spectral sensitivity characteristics of an illuminance sensor chip according to the present invention and a conventional illuminance sensor chip having different thicknesses of P-type semiconductor layers.

FIG. 5 is a graph showing an example of a measurement result for determining a thickness of a P-type semiconductor layer of the illuminance sensor chip.

FIG. 6 is a perspective view schematically showing a part of an illuminance measuring device according to a second embodiment of the present invention.

FIG. 7 is a graph showing spectral sensitivity characteristics of the two illuminance sensors shown in FIG.

FIG. 8 is a perspective view schematically showing a part of an illuminance measuring device according to a third embodiment of the present invention.

FIG. 9 is a sectional view taken along line IX-IX in FIG. 8;

[Explanation of symbols]

X1 to X3 Illuminance measuring device 1, 5, 7 Illuminance sensor 2, 6 Illuminance calculation unit 13 (First) illuminance sensor chip 15 (First) 1 resin package 33 N ^- type semiconductor layer (first semiconductor layer) 34 P Type semiconductor layer (second semiconductor layer) 53 (second, additional) illuminance sensor chip 55 (second) resin package 71 third resin package D (P-type semiconductor layer) thickness

Continued on the front page F term (reference) 2G065 AA03 AB04 BA07 BA09 BB25 BC05 BC13 BC33 BC35 BD01 CA08 2H093 ND01 ND04 ND08 NE05 NG20 5F049 MA12 MB03 MB12 NA10 NB10 PA03 SS03 SZ12 TA03 TA09 UA20 WA03 5F088 AA08 AB03 JA03 JA03

Claims (18)

[Claims] A first semiconductor layer; and a second semiconductor layer joined to the first semiconductor layer, wherein the second semiconductor layer is provided at a junction between the first semiconductor layer and the second semiconductor layer. When light is incident through the layer, it is configured to output an electric signal in accordance with the amount of light incident on the junction, and the thickness of the second semiconductor layer is determined by the output amount of the electric signal. An illuminance sensor chip characterized in that a peak sensitivity wavelength in a spectral sensitivity characteristic with reference to a wavelength is set within a wavelength range of visible light. 2. The illuminance sensor chip according to claim 1, wherein the thickness of the second semiconductor layer is 4 μm or less. 3. The illuminance sensor chip according to claim 2, wherein the thickness of the second semiconductor layer is 2 μm or more. 4. The peak sensitivity wavelength is from 580 to 600.
The illuminance sensor chip according to claim 1, wherein the illuminance sensor chip has a thickness in nm. 5. The illuminance sensor chip according to claim 1, wherein said second semiconductor layer is a silicon semiconductor. 6. The illuminance sensor chip according to claim 1, wherein the illuminance sensor chip is configured as a phototransistor. 7. The illuminance sensor chip according to claim 6, wherein said phototransistor has an npn junction. 8. An illuminance sensor comprising the illuminance sensor chip according to claim 1. 9. An additional illuminance sensor chip having the same or substantially the same spectral sensitivity characteristics as the illuminance sensor chip, and an additional illuminance sensor chip for absorbing incident light and then receiving incident light. The illuminance sensor according to claim 8, further comprising: a visible light cut section. 10. The illuminance sensor according to claim 9, wherein the additional illuminance sensor chip is sealed in a resin package colored black. 11. The illuminance sensor chip according to claim 9, wherein the illuminance sensor chip is sealed in a transparent first resin package, and the additional illuminance sensor chip is sealed in a second resin package colored black. Illuminance sensor. 12. The first and second resin packages are sealed by a transparent third resin package.
The illuminance sensor according to claim 11. 13. A semiconductor device comprising: a first semiconductor layer; a second semiconductor layer joined to the first semiconductor layer; First and second illuminance sensor chips configured to output an electric signal according to the amount of light incident on the bonding portion when light enters through the semiconductor layer, and after absorbing visible light A visible light cut section for receiving incident light with respect to a joint of the second illuminance sensor chip; and an illuminance for calculating illuminance based on outputs from the first and second illuminance sensor chips. An illuminance measurement device, comprising: a calculation unit. 14. The illuminance measuring device according to claim 13, wherein the second illuminance sensor chip has the same or substantially the same spectral sensitivity characteristics as the first illuminance sensor chip. 15. The illuminance calculation unit calculates illuminance based on a signal corresponding to a difference between an output from the first illuminance sensor chip and an output from the second illuminance sensor chip. Item 15. The illuminance measuring device according to item 13 or 14. 16. A method for measuring illuminance using first and second illuminance sensor chips, wherein the first and second illuminance sensor chips include a first semiconductor layer and a first semiconductor layer. A joined second semiconductor layer;
And outputting an electric signal according to the amount of light incident on the junction when light is incident on the junction between the first semiconductor layer and the second semiconductor layer via the second semiconductor layer. An illuminance is calculated based on outputs from the first and second illuminance sensors. 17. The first illuminance sensor chip and the second illuminance sensor chip have the same or substantially the same spectral sensitivity characteristics, and the second illuminance sensor chip includes: The illuminance measurement method according to claim 16, wherein the light is made incident after absorbing visible light. 18. An illuminance is calculated based on a signal corresponding to a difference between an output from the first illuminance sensor chip and an output from the second illuminance sensor chip.
7. The illuminance measurement method according to 7.