JP5757614B2 - Image sensor - Google Patents

Description

  The present invention relates to an image sensor that photoelectrically converts light incident on a depletion region generated in a pn junction.

  A conventional image sensor is formed of a silicon (Si) semiconductor, and can detect light in a wavelength range from visible light to near infrared (about 400 nm to about 1100 nm). However, due to the relationship between the depth of the depletion region of the pn junction formed in the image sensor and the light penetration length, there is a problem that the light receiving sensitivity decreases as the wavelength of incident light increases. For example, when the depletion region is formed several μm from the surface of the image sensor, the penetration length of near infrared rays into silicon is several tens of μm, so that most of the near infrared rays cannot be collected in the depletion region.

  As techniques related to the above problem, techniques disclosed in Patent Documents 1 and 2 are disclosed. The technique shown in Patent Document 1 includes a photodiode having a depletion layer region generated at a pn junction between a first conductivity type semiconductor substrate and a second conductivity type semiconductor locally formed on the surface side as a photoelectric conversion region; In a semiconductor imaging device including a pixel circuit that forms a CMOS image sensor together with a photodiode formed on the surface side of a semiconductor substrate, a cavity is formed in the semiconductor substrate, and the back surface (or side surface or surface of the semiconductor substrate is interposed through the cavity) In this configuration, light is irradiated onto the photoelectric conversion region of the photodiode from the side), whereby the incident near-infrared light can pass through the pn junction of the photodiode having the largest signal absorption for a long time. By providing the reflective film, the reflected light passes through the pn junction again, so that the sensitivity is further increased.

  In the technique disclosed in Patent Document 2, a pixel cell Cel is formed on a first substrate surface side of a first conductivity type (n-type) formed on the first substrate surface side of the substrate, and on the second substrate surface side of the first well. And a second well of the second conductivity type (p-type), the first well functions as a light receiving portion that receives light from the first substrate surface side, and a photoelectric conversion function and charge storage function of the received light And the second well detects a charge accumulated in the light receiving portion of the first well, and a MOS transistor having a threshold modulation function is formed, and a p-type is formed on the side wall of the first well so as to surround them. An element isolation layer is formed.

JP 2009-238985 A JP 2009-152234 A

  However, the technique disclosed in Patent Document 1 requires the formation of a cavity and a reflective film, which complicates the formation process, and has a problem that the light receiving sensitivity is not sufficient even when a reflective film is provided. .

  The technique shown in Patent Document 2 is to cope with light having a long wavelength by making the substrate relatively thick (about 6 μm to 10 μm) and using reflection by a reflector. In addition to being complicated, the light receiving sensitivity is not sufficient.

Therefore, the present invention provides an imaging device that can increase the light receiving sensitivity even for light having a long wavelength and can be formed at low cost by a simple process.

  An image sensor disclosed in the present application is an image sensor that photoelectrically converts light incident on a depletion region generated at a junction between a first conductivity type semiconductor substrate and a second conductivity type semiconductor, wherein the second conductivity type semiconductor is the first conductivity type. A plurality of conductive layers are arranged inside the one conductive type semiconductor substrate so as to extend in the longitudinal direction along the surface direction of the first conductive type semiconductor substrate and the incident direction of the light.

  As described above, in the imaging device disclosed in the present application, a plurality of second conductivity type (here, n-type) semiconductors are arranged inside the first conductivity type (here, p-type) semiconductor substrate. In addition, since the first conductive type semiconductor substrate is disposed so as to extend in the longitudinal direction along the surface direction of the first conductive type semiconductor substrate and the incident direction of light, the incident light enters the longitudinal direction of the n-type semiconductor. By increasing the time during which incident light stays in the depletion region, it is possible to increase the light receiving sensitivity. In addition, since the n-type semiconductor can be formed simply by burying it in the p-type semiconductor substrate, there is an effect that the formation process can be simplified and efficiently manufactured.

  The image sensor is applied as a line sensor.

  In the imaging device disclosed in the present application, the second conductive semiconductor is incident on one end of the second conductive semiconductor in a longitudinal direction of the light incident side and the light in the first conductive semiconductor substrate. It is characterized in that the distance from the side surface portion is set at a predetermined distance or less.

  As described above, in the imaging device disclosed in the present application, the distance between the one end portion on the light incident side in the longitudinal direction of the second conductive type semiconductor and the side surface portion on which light enters the first conductive type semiconductor substrate is set. By performing dicing or the like to a predetermined distance or less, there is an effect that it is possible to prevent the attenuation of incident light due to the thickness of the side surface portion of the first conductivity type semiconductor substrate and to increase the light receiving sensitivity.

  In the imaging device disclosed in the present application, the second conductive semiconductor is disposed such that a distance from the substrate surface of the first conductive semiconductor substrate is a predetermined distance or less, and the second conductive semiconductor is disposed. The provided first conductive type semiconductor substrate is laminated in a plurality of layers.

  As described above, in the imaging device disclosed in the present application, the first conductive semiconductor substrate in which a plurality of second conductive semiconductors are disposed is stacked in a plurality of layers, whereby the second conductive semiconductor is formed into one pixel. In addition to being able to be applied as an image sensor with high light receiving sensitivity, the entire element can be compactly formed even when the first conductive semiconductor substrate is thinly cut to form a laminated structure. .

  The imaging device disclosed in the present application is a process of converting at least the electric charge output from the depletion region into an output signal adjacent to the other end on the opposite side to the light incident side in the second conductivity type semiconductor A conversion circuit section that performs the above-described operation, and a pad section that is disposed on the upper surface of the first conductive semiconductor substrate, is adjacent to the conversion circuit section, and is electrically connected to the conversion circuit section. The distance from the pad portion increases in order from the upper layer.

  As described above, the imaging device disclosed in the present application includes a conversion circuit unit that performs processing for converting charges into an output signal, and a pad unit that is electrically connected to the conversion circuit unit. As the distance between and increases gradually from the upper layer, each layer (one layer forms a line sensor) can be electrically connected to the outside, and the signal of each layer can be extracted and used as an image sensor There is an effect that it can be utilized.

  The imaging device disclosed in the present application is based on the thickness of the first conductive semiconductor substrate and the thickness of the second conductive semiconductor based on the position of the lens on the light incident side in the longitudinal direction of the second conductive semiconductor. It is characterized by comprising a lens fluctuation portion that fluctuates.

  As described above, in the imaging device disclosed in the present application, the upper and lower positions of the lens are continuously changed by changing the position of the lens based on the thicknesses of the first conductive semiconductor substrate and the second conductive semiconductor. And the optical axis of the incident light is corrected, and the image of the entire display object is generated while partially receiving the light from the display object, so that the resolution can be greatly increased.

  The imaging device disclosed in the present application is characterized in that the incident light is near infrared rays.

  As described above, the image sensor disclosed in the present application has an effect that it can receive near-infrared light, which has poor light reception sensitivity in the conventional image sensor, with high sensitivity.

  The image pickup device disclosed in the present application is characterized in that a length in a longitudinal direction of the second conductive semiconductor is equal to or longer than a penetration length of the near infrared light into the second conductive semiconductor.

  As described above, in the imaging device disclosed in the present application, since the length in the longitudinal direction of the second conductivity type semiconductor is equal to or longer than the penetration length of the near infrared light with respect to the second conductivity type semiconductor, The light receiving sensitivity can be greatly increased by covering the above.

  In the imaging device disclosed in the present application, a plurality of the second conductivity type semiconductors are arranged in the longitudinal direction of the second conductivity type semiconductor, and correspond to the penetration length of the incident light with respect to the second conductivity type semiconductor. The plurality of second conductivity type semiconductors are arranged at positions.

  As described above, in the imaging device disclosed in the present application, since a plurality of second conductive semiconductors are arranged corresponding to the penetration length of incident light into the second conductive semiconductor, a special filter or the like is provided. Thus, there is an effect that light in a wavelength region corresponding to the penetration length can be easily photoelectrically converted as color information. That is, an image sensor as a color image sensor can be obtained without using a color filter or the like.

  In the imaging device disclosed in the present application, the length in the longitudinal direction of each of the plurality of second conductivity type semiconductors arranged in order increases from one end on the light incident side to the other end on the opposite side. It is characterized by being arranged.

  As described above, in the imaging device disclosed in the present application, the length in the longitudinal direction of each second conductive type semiconductor is sequentially increased from one end on the light incident side to the other end on the opposite side. Because it is arranged, the longer the penetration length is, the more the attenuation occurs, the longer the second conductivity type semiconductor absorbs a sufficient amount of light, and uniformly absorbs light in various wavelength regions as a whole. Thus, there is an effect that a highly sensitive image sensor can be realized.

  The image sensor disclosed in the present application includes four second conductive semiconductors, and photoelectrically converts blue light, green light, red light, and near infrared light in order from the light incident side. It is characterized by this.

As described above, in the imaging device disclosed in the present application, the four second conductivity type semiconductors are arranged, and the blue light, the green light, the red light, and the near-infrared light are sequentially arranged from the light incident side. As a result, the color image sensor can be realized without using a color filter.

  The imaging device disclosed in the present application is characterized in that a length of each of the plurality of second conductive semiconductors arranged in a longitudinal direction is equal to or longer than a penetration length of each incident light into the second conductive semiconductor. Is.

  As described above, in the imaging device disclosed in the present application, the length of the second conductivity type semiconductor is such that each incident light (blue light, green light, red light, near infrared light, etc.) with respect to the second conductivity type semiconductor. ), The absorption length of each incident light can be covered and the light receiving sensitivity can be significantly increased.

  The imaging device disclosed in the present application includes a reflective material that reflects the light transmitted through the second conductive semiconductor at the other end opposite to the light incident side in the second conductive semiconductor. It is characterized by.

  As described above, in the imaging device disclosed in the present application, the reflective material that reflects the light transmitted through the second conductive semiconductor to the other end on the side opposite to the light incident side of the second conductive semiconductor. Therefore, the light transmitted through the second conductivity type semiconductor is reflected by the reflecting material, so that more light is absorbed and the light receiving sensitivity can be increased. Further, by providing the reflecting material, it is possible to absorb the light transmitted through the second conductive type semiconductor again, so that the length of the second conductive type semiconductor is shortened without causing a decrease in the light receiving sensitivity. There exists an effect that an element can be reduced in size.

  When a plurality of second conductivity type semiconductors are arranged in the longitudinal direction, the reflective material is provided only at the other end of the second conductivity type semiconductor arranged at the position farthest from the light incident direction. Shall.

  In the imaging device disclosed in the present application, the four second conductive semiconductors are arranged, and the first, second, and third semiconductors are sequentially arranged from the light incident side to the four second conductive semiconductors. A wavelength corresponding to a charge amount ratio of a signal obtained by photoelectrically converting light incident on each depletion region formed of the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor, as the semiconductor and the fourth semiconductor. Wavelength information storage means for storing signal, signal input means for inputting signal charges detected in the depletion regions of the four second-conductivity-type semiconductors, and based on the signal charge amount of signal charges input by the signal input means A signal component calculation means for calculating the signal charge amount of the blue light, the green light, the red light, and the near infrared light in the incident light according to the following equation;

（ただし、Ｂは入射光における青色光、Ｇは入射光における緑色光、Ｒは入射光における赤色光、ＩＲは入射光における近赤外光の信号電荷量とし、Ｘは第１半導体の空乏領域で検知された信号電荷量、Ｙは第２半導体の空乏領域で検知された信号電荷量、Ｚは第３半導体の空乏領域で検知された信号電荷量、Ｗは第４半導体の空乏領域で検知された信号電荷量とし、ａ_ijは素子ごとに決まる入射光の分光特性を示す係数する。）、前記信号成分演算手段で算出された信号電荷量に基づいて、各信号電荷量の割合を算出し、当該算出さ
れた信号電荷量の割合に対応付けられた波長を前記波長情報記憶手段から読み出して、前記入射光の波長として決定する波長決定手段とを備えるものである。

(B is the blue light in the incident light, G is the green light in the incident light, R is the red light in the incident light, IR is the signal charge amount of the near infrared light in the incident light, and X is the depletion region of the first semiconductor. , Y is the signal charge amount detected in the depletion region of the second semiconductor, Z is the signal charge amount detected in the depletion region of the third semiconductor, and W is detected in the depletion region of the fourth semiconductor. And a _ij is a coefficient indicating the spectral characteristic of incident light determined for each element.) Based on the signal charge amount calculated by the signal component calculation means, the ratio of each signal charge amount is calculated. And a wavelength determining unit that reads out the wavelength associated with the calculated ratio of the signal charge amount from the wavelength information storage unit and determines the wavelength as the wavelength of the incident light.

As described above, in the imaging device disclosed in the present application, the incident light is input from the signal charge amount detected in the depletion region of the first semiconductor to the fourth semiconductor based on the matrix of a _ij indicating the spectral characteristics of the imaging element. By calculating the wavelength component of light, there is an effect that the wavelength of incident light can be accurately determined.

  In the imaging device disclosed in the present application, the coefficient indicating the spectral specification of incident light determined for each element is that of the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor when the incident light is white light. Each signal charge amount detected in the depletion region is a representative value calculated for each of the wavelength regions divided into a plurality.

As described above, in the imaging device disclosed in the present application, the signal charge amount detected in the depletion region of the first semiconductor to the fourth semiconductor detected with white light is used for each wavelength region divided into a plurality of regions. Since the representative value of the signal charge amount is calculated and the representative value is set to the coefficient a _ij , an ideal coefficient a _ij can be obtained from white light including various wavelengths, and the wavelength component of incident light can be accurately determined. There is an effect that it can be calculated.

  In the imaging device disclosed in the present application, the representative value is a plurality of divided wavelength regions for each signal charge amount detected in the depletion regions of the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor. Or an average value calculated from the total value of the maximum charge amount and the minimum charge amount.

  Thus, in the imaging apparatus disclosed in the present application, the representative value is divided into a plurality of signal charge amounts detected in the depletion regions of the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor. By calculating the average value calculated from the total value for each wavelength region or the average value calculated from the sum of the maximum charge amount and the minimum charge amount, the wavelength component of the incident light can be calculated more accurately. There is an effect that can be done.

  The imaging device disclosed in the present application includes light intensity calculation means for calculating the intensity of the incident light based on the ratio of each signal charge amount to the total amount of signal charges in the signal charge amount calculated by the signal component calculation means. Is.

  Thus, in the imaging apparatus disclosed in the present application, in order to calculate the intensity of incident light based on the ratio of each signal charge amount in the signal charge amount calculated by the signal charge amount calculation unit and the total charge amount, By calculating not only the color indicated by the wavelength of the incident light but also the light intensity, there is an effect that a higher-performance imaging device can be realized.

1 is an overall perspective view of an image sensor according to a first embodiment. It is a processing sectional view of the image sensor concerning a 1st embodiment. It is a figure which shows the circuit of the image pick-up element which concerns on 1st Embodiment. It is a whole perspective view of the image sensor concerning a 2nd embodiment. It is a top view of each layer in the image sensor according to the second embodiment. It is a figure which shows the example of arrangement | positioning of the pad part in the image pick-up element which concerns on 2nd Embodiment. It is a figure which shows the process which adjusts the position of a lens in the image pick-up element which concerns on 3rd Embodiment. It is a figure which shows the color filter by a Bayer system. It is a figure which shows the process of the color imaging by a color separation photodiode system. It is a whole perspective view of the image sensor concerning a 4th embodiment. It is sectional drawing of the image pick-up element which concerns on 4th Embodiment. It is sectional drawing at the time of setting it as a laminated structure in the image pick-up element which concerns on 4th Embodiment. It is an upper surface figure of each layer in an image sensor concerning a 4th embodiment. It is a figure which shows the example of arrangement | positioning of the pad part in the image pick-up element which concerns on 4th Embodiment. It is a figure which shows the process which adjusts the position of a lens in the image pick-up element which concerns on 4th Embodiment. It is a whole perspective view of the image sensor concerning a 5th embodiment. It is a functional block diagram of the imaging device concerning a 6th embodiment. It is sectional drawing of the image pick-up element in the imaging device which concerns on 6th Embodiment. It is a figure which shows the signal charge amount when white light is made into incident light in the image sensor which concerns on 6th Embodiment. It is a figure which shows the characteristic of the wavelength component in case the white light is incident light in the image pick-up element which concerns on 6th Embodiment. It is a 1st flowchart which shows operation | movement of the image pick-up element which concerns on 6th Embodiment. It is a 2nd flowchart which shows operation | movement of the image pick-up element which concerns on 6th Embodiment.

  Embodiments of the present invention will be described below. The present invention can be implemented in many different forms. Therefore, the present invention should not be construed based only on the description of the present embodiment. Also, the same reference numerals are given to the same elements throughout the present embodiment.

(First embodiment of the present invention)
An image sensor according to this embodiment will be described with reference to FIGS. 1 to 3. 1 is an overall perspective view of the image sensor according to the present embodiment, FIG. 2 is a cross-sectional view of the image sensor according to the present embodiment, and FIG. 3 is a diagram illustrating a circuit of the image sensor according to the present embodiment. .

  In FIG. 1, an imaging device 1 includes a p-type silicon substrate 2 and a plurality of rod-like n embedded in the upper surface of the p-type silicon substrate 2 in parallel along the surface direction of the p-type silicon substrate 2. Type silicon semiconductor 3. As shown in FIG. 1, incident light is irradiated from the longitudinal direction of the n-type silicon semiconductor 3, that is, from the side surface direction of the p-type silicon substrate 2, and is generated at the pn junction between the p-type silicon substrate 2 and the n-type silicon semiconductor 3. Absorbed in a depletion region (not shown), electron-hole pairs are generated by the absorbed incident light and converted into signal charges.

  The length L of the n-type silicon semiconductor 3 is preferably at least equal to or greater than the penetration length of incident light into silicon. Here, a description will be given mainly using near infrared rays having a long wavelength and poor light receiving sensitivity. The wavelength of near infrared rays is about 780 nm to 1100 nm, and the average penetration length with respect to silicon is several tens of μm. Therefore, it is desirable that the value of L is about several tens of μm to several hundreds of μm.

The distance W between the side surface 2a of the p-type silicon substrate 2 and the side surface 31 of the n-type silicon semiconductor 3 is such that near infrared rays irradiated from the side surface of the p-type silicon substrate 2 are In order to prevent it from being attenuated by silicon, it is processed as short as possible by applying dicing or the like. As shown in FIG. 2, in order to prevent near-infrared rays from being attenuated by the shaded area in FIG. 2A, the silicon on the side surface is cut as shown in FIG.

  By irradiating incident light from the longitudinal direction of the n-type silicon semiconductor 3, it extends in the longitudinal direction generated between the n-type silicon semiconductor 3 having a length L at least about the penetration length and the p-type silicon substrate 2. Since the near infrared ray passes through the depletion region, the opportunity to absorb the near infrared ray is increased and the light receiving sensitivity is increased. Further, since the distance W between the side surface 2a of the p-type silicon substrate 2 and the side surface 31 of the n-type silicon semiconductor 3 is cut to a minimum length, attenuation of incident near-infrared rays can be minimized, Furthermore, the light receiving sensitivity is increased.

  As shown in FIG. 1, the lower surface portion of the p-type silicon substrate 2 is subjected to a process of scraping off the thickness T of the p-type silicon substrate 2 to at least a thickness t at which a depletion region is formed. Thus, the image pickup device 1 can be reduced in size and applied to various devices.

  Next, the conversion of the absorbed near infrared ray into a charge signal will be described. FIG. 3A is a top view of the image sensor 1, and the conversion circuit unit 5 provided adjacent to the side surface 32 opposite to the side surface 31 on which the near infrared rays are incident in the n-type silicon semiconductor 3, and the conversion A pad 6 adjacent to the circuit unit 5 and electrically connected to the conversion circuit unit 5 is provided on the upper surface of the n-type silicon semiconductor 3. FIG. 3B is a circuit diagram of the conversion circuit unit 5. When the photodiode receives light at the pn junction, a signal carrier accompanying photoelectric conversion is generated. By accumulating the signal carrier in the junction volume of the photodiode at the pn junction, the cathode potential of the photodiode changes. The AMI transistor converts this cathode potential change into a current, and the I / V conversion circuit converts the current into a signal voltage. The bias voltage PixVb provides a photodiode reset signal, and PixRst is a logic signal that initializes the photodiode to the reset voltage. The converted signal voltage is output to an external device via the pad 6.

  Note that the p-type and n-type of the p-type silicon substrate 2 and the n-type silicon semiconductor 3 may be reversed. In addition, the image sensor according to the present embodiment functions as a line sensor.

(Second embodiment of the present invention)
An image sensor according to this embodiment will be described with reference to FIGS. FIG. 4 is an overall perspective view of the image sensor according to the present embodiment, FIG. 5 is a top view of each layer in the image sensor according to the present embodiment, and FIG. 6 is an example of the arrangement of pad portions in the image sensor according to the present embodiment. FIG.

  The image sensor according to the present embodiment is an image sensor in which the image sensor according to the first embodiment is stacked in a plurality of layers. In addition, in this embodiment, the description which overlaps with the said 1st Embodiment is abbreviate | omitted.

  As illustrated in FIG. 4, the image sensor 1 according to the present embodiment includes a plurality of layers of the image sensor 1 as a line sensor according to the first embodiment, and receives light from a side surface portion. By stacking a plurality of pixels, pixels can be arranged in a two-dimensional matrix on the side surface of the image sensor 1, and the line sensor according to the first embodiment can be used as an image sensor. In order to increase the resolution by arranging more pixels, as shown in FIG. 1, the p-type silicon substrate 2 having a thickness T is processed until the remaining thickness t is reached. At this time, from the viewpoint of increasing the resolution of the stacked image pickup devices 1, the thin film is processed so that the remaining thickness t is as small as possible.

FIG. 5 shows an arrangement example of the n-type silicon semiconductor 3, the conversion circuit unit 5, and the pad 6 in each layer of the image sensor 1. 5A is the top line sensor, FIG. 5B is the second line sensor from the top layer, FIG. 5C is the third line sensor from the top layer, and FIG. 5D is the top layer. The nth line sensor is shown. As shown in FIG. 5, the distance between the conversion circuit unit 5 and the pad 6 increases sequentially from the upper layer to the lower layer. A stack of these layers is shown in FIG.

  As shown in FIG. 6, information for each line sensor can be taken out via the pad 6 by changing the distance between the conversion circuit unit 5 and the pad 6 for each layer. In this way, information can be extracted for each layer, and can be used as an image sensor.

  Here, the arrangement of the pads 6 is varied only in one direction (leftward in FIG. 6) as the lower layer is reached, but there are a plurality of arrangements depending on the position and device where the image sensor 1 is installed. The arrangement of the pads 6 may be different in the direction (for example, three directions other than the light irradiation direction).

(Third embodiment of the present invention)
The image sensor according to the present embodiment will be described with reference to FIG. FIG. 7 is a diagram illustrating processing for adjusting the position of the lens in the image sensor according to the present embodiment.

  The image pickup device according to the present embodiment corrects the optical axis of incident light by continuously shifting the vertical position of the lens, and partially receives light from the display target of the lens while displaying an image of the entire display target. Is to be generated. In addition, in this embodiment, the description which overlaps with the said 1st, 2nd embodiment is abbreviate | omitted.

  In FIG. 7, a lens 7 is provided in a direction in which light in the image sensor 1 is incident, and this lens 7 performs an operation of continuously shifting in the vertical direction under the control of a lens changing unit (not shown). By changing the position of the lens 7, the optical axis of the incident light is corrected, and the entire image is generated while partially receiving the light from the display target, thereby increasing the resolution. FIG. 7A shows a case where the resolution is increased by correcting the thickness T of the p-type silicon substrate 2 by about T. In FIG. 7B, the imaging area is divided into a plurality of sections (here, divided into three sections), and by finally capturing an image for each section, it becomes possible to greatly increase the resolution finally. ing.

  In addition, the mechanism of the lens 7 and the lens fluctuation | variation part can be easily implement | achieved by using techniques, such as camera shake correction generally utilized.

(Fourth embodiment of the present invention)
The image sensor according to the present embodiment will be described with reference to FIGS. 8 is a diagram illustrating a color filter using the Bayer method, FIG. 9 is a diagram illustrating color imaging processing using a color separation photodiode method, FIG. 10 is an overall perspective view of the image sensor according to the present embodiment, and FIG. FIG. 12 is a cross-sectional view of the imaging device according to the present embodiment in a stacked structure, and FIG. 13 is a top view of each layer in the imaging device according to the present embodiment. FIG. 14 is a diagram illustrating an arrangement example of pad portions in the image sensor according to the present embodiment, and FIG. 15 is a diagram illustrating processing for adjusting the lens position in the image sensor according to the present embodiment.

  As a spectroscopic technique in the color image sensor, the Bayer method shown in FIG. 8 is realized. This Bayer method uses a color filter that transmits light in a specific wavelength region, and a green (G) filter is arranged on a pixel in a line-sequential manner with red (R) and blue (B) filters. ing. As shown in FIG. 8, color image shooting is realized by generating color data of three primary colors by two pixels of two green, red, and blue.

When this method is used, each pixel having a color filter cuts light other than the color, and the amount of light that can be absorbed decreases. Also, the creation of the color filter is not included in the normal semiconductor (CMOS) manufacturing process, and a separate process for creating the color filter is required, which makes the work complicated and inefficient. .

  The color separation photodiode method shown in FIG. 9 is another spectroscopic technique in a color image sensor. As shown in FIG. 9, color imaging is performed using a feature that has pixels in which n-type, p-type, and n-type silicon layers are alternately stacked on a p-type silicon substrate, and the penetration depth of light into silicon varies depending on the wavelength. Is realized. Blue light with a short penetration depth generates electron-hole pairs at the shallow pn junction, and green light with a penetration depth longer than blue light generates electron-hole pairs at the middle pn junction. Red light, which is longer than green light, generates electron-hole pairs at the deep pn junction.

  Since the primary color data is generated from the electron-hole pairs generated at each pn junction in one pixel, the pixel utilization efficiency is superior to the Bayer method of FIG. In addition, since no color filter is used, it is possible to expect an improvement in light receiving sensitivity by suppressing a loss of available light amount. However, since the penetration length of green light and red light into silicon reaches several tens of μm, it is necessary to form an n-type silicon layer in a region several tens of μm deep from the surface of the p-type silicon substrate. Additional manufacturing steps are required. Further, since the signal electrodes are not independent for each color, a separate process for separating the signals of the three colors is required.

  In the imaging device 1, a plurality of n-type silicon semiconductors 3 are arranged in the longitudinal direction, and the plurality of n-type silicon semiconductors 3 are p-type silicon substrates corresponding to the penetration length corresponding to the wavelength region of incident light. 2 is embedded. That is, a color line sensor and a color image sensor that can photoelectrically convert light of a color corresponding to a wavelength region are realized.

  FIG. 10 is an overall perspective view of the image sensor 1 according to the present embodiment. The difference from the image sensor 1 shown in FIG. 1 is that four n-type silicon semiconductors 3 are arranged. In FIG. 10, an n-type silicon semiconductor 3a is a silicon semiconductor for detecting blue light, an n-type silicon semiconductor 3b is a silicon semiconductor for detecting green light, an n-type silicon semiconductor 3c is a silicon semiconductor for detecting red light, and an n-type silicon semiconductor. 3d is a silicon semiconductor for detecting near infrared light. This order is based on the fact that the penetration depth of light into silicon is blue light <green light <red light <near infrared light, and blue light, green light, red light, and near light along the light incident direction. A pn junction for detecting infrared light is formed. Since these pn junctions are independent from each other, it is possible to individually extract signals of each color.

  FIG. 11 is a cross-sectional view of the image sensor 1 in FIG. 10, and each of the n-type silicon semiconductors 3 arranged in a plurality (four) can split incident light with respect to the light incident direction (longitudinal direction). The optimal length is set and formed. If the penetration length into silicon in which 99% of the amount of incident light is absorbed is defined as 99% penetration length, the 99% penetration length of blue light (wavelength range is 430 nm to 490 nm) is 0.3 μm to 2.3 μm, 99% penetration length for green light (wavelength range 490 nm to 550 nm) is 1.1 μm to 5.0 μm, 99% penetration length for red light (wavelength range 640 nm to 780 nm) is 6.2 μm to 40 μm, near red light ( The 99% penetration length in the wavelength range from 780 nm is 40 μm. Therefore, for example, by setting the length and position of each of the n-type silicon semiconductors 3a to 3d as shown in FIG. 11, the incident light can be accurately and efficiently dispersed.

At this time, similarly to the case of FIG. 2 in the first embodiment, the distance W between the side surface 2a of the p-type silicon substrate 2 and the side surface 31 of the n-type silicon semiconductor 3a minimizes attenuation of incident light. Therefore, process as short as possible. Preferably, W <0.8 μm. Here, four n-type silicon semiconductors 3 are arranged to detect blue light, green light, red light, and near-infrared light, respectively. The number of divisions of the n-type silicon semiconductor 3 and the arrangement and function of each can be designed as appropriate, such as detecting light and red light, respectively.
Furthermore, the image sensor shown in FIGS. 10 and 11 functions as a line sensor.

  The image sensor 1 as a line sensor shown in FIG. 10 and FIG. 11 realizes an image sensor in the same manner as the image sensor 1 according to the second embodiment by stacking in a plurality of layers as shown in FIG. Can do. Again, from the viewpoint of processing the thickness T of the p-type silicon substrate 2 until the remaining thickness t is increased and increasing the resolution of the stacked image pickup device 1, at least the n-type silicon semiconductor 3 and the depletion region are left while remaining. The thickness t is processed as thin as possible.

  When line sensors are stacked to realize an image sensor, it is necessary to supply power to each line sensor, supply signals, or take them out. FIG. 13 shows an arrangement example of the n-type silicon semiconductors 3 (3a to 3d), the conversion circuit unit 5, and the pads 6 in each layer of the image sensor 1, as in FIG. 13A is the top layer sensor, FIG. 13B is the second line sensor from the top layer, FIG. 13C is the third line sensor from the top layer, and FIG. 13D is the top layer. The nth line sensor is shown. As shown in FIG. 13, the distance between the conversion circuit unit 5 and the pad 6 increases sequentially from the upper layer to the lower layer. A laminate of these layers is shown in FIG.

  As shown in FIG. 14, by changing the distance between the conversion circuit unit 5 and the pad 6 for each layer, the information for each line sensor can be extracted through the pad 6 including the color information. Thus, by being able to take out information for each layer, it can be used as an image sensor, and the bonding process between the bonding wire and the pad 6 can be facilitated.

  FIG. 15 shows a process for adjusting the position of the lens, as with the image sensor according to the third embodiment, as a method for improving the resolution of the image sensor 1 as a color image sensor. Here again, as in the case of the third embodiment, the optical axis of the incident light is corrected by continuously shifting the vertical position of the lens 7 and the light from the display object of the lens 7 is partially received. However, the resolution can be increased by generating an image of the entire display target.

  In addition, the mechanism of the lens 7 and the lens fluctuation | variation part can be easily implement | achieved by using techniques, such as camera shake correction generally utilized.

  As described above, the image sensor according to the present embodiment can easily photoelectrically convert light of a color corresponding to the wavelength region without providing a special filter or the like, and can function as a color image sensor. Further, since the length in the longitudinal direction of the n-type silicon semiconductor 3 is embedded so as to increase sequentially from one end portion on the light incident side to the other end portion on the opposite side, the intrusion length is long and attenuated. As the amount of light generated increases, the n-type silicon semiconductor 3 is lengthened to absorb a sufficient amount of light, and the light in various wavelength regions as a whole is uniformly absorbed, thereby realizing a highly sensitive imaging device. .

(Fifth embodiment)
An image sensor according to this embodiment will be described with reference to FIG. FIG. 16 is an overall perspective view of the image sensor according to the present embodiment. FIG. 16A shows a case where one n-type silicon semiconductor 3 is arranged in the longitudinal direction of the n-type silicon semiconductor 3, and FIG. 16B shows four n in the longitudinal direction of the n-type silicon semiconductor 3. This is a case where the type silicon semiconductor 3 is disposed.

As shown in FIG. 16, a reflecting material 8 that reflects the light transmitted through the n-type silicon semiconductor 3 is provided at the other end of the n-type silicon semiconductor 3 opposite to the light incident side. This reflecting material can be formed, for example, by forming a groove for embedding the reflecting material in the p-type silicon substrate 2 by a technique such as etching and embedding the reflecting material 8 such as aluminum therein.

  Thus, by providing the reflecting material 8, the light transmitted through the n-type silicon semiconductor 3 is reflected by the reflecting material 8 to absorb more light, and the light receiving sensitivity can be increased. Further, by providing the reflecting material 8, it is possible to absorb the light transmitted through the n-type silicon semiconductor 3 again. Therefore, when the length of the n-type silicon semiconductor 3 shown in FIG. Even if it exists, it becomes possible to miniaturize an image pick-up element, without causing the fall of a light receiving sensitivity.

  As shown in FIG. 16B, when a plurality of n-type silicon semiconductors 3 are arranged in the longitudinal direction, the n-type silicon semiconductor 3d arranged at the farthest position from the incident direction of light. The reflective material 8 is provided only at the other end.

  Although the present invention has been described with the above embodiments, the technical scope of the present invention is not limited to the scope described in the embodiments, and various modifications or improvements can be added to these embodiments. .

(Sixth embodiment)
An imaging apparatus according to the present embodiment will be described with reference to FIGS. FIG. 17 is a functional block diagram of the imaging device according to the present embodiment, FIG. 18 is a cross-sectional view of the imaging device in the imaging device according to the present embodiment, and FIG. 19 is incident white light in the imaging device according to the present embodiment. FIG. 20 is a diagram illustrating a signal charge amount when light is used, FIG. 20 is a diagram illustrating characteristics of a wavelength component when white light is incident light in the image sensor according to the present embodiment, and FIG. 21 is a diagram according to the present embodiment. A first flowchart showing the operation of the image sensor, and FIG. 22 is a second flowchart showing the operation of the image sensor according to the present embodiment.

  In FIG. 17, the imaging apparatus 10 includes an imaging device 1, a signal input unit 11, a coefficient calculation unit 12, a signal component calculation unit 13, a wavelength information storage unit 14, a wavelength determination unit 15, and a coefficient information storage unit 16. As shown in FIG. 18, the image pickup device 1 has a plurality (four) of n-type silicon semiconductors 3 (3a to 3d) arranged in the same manner as in the case shown in FIG. The first semiconductor (n-type silicon semiconductor 3a), second semiconductor (n-type silicon semiconductor 3b), third semiconductor (n-type silicon semiconductor 3c) and fourth semiconductor (n-type silicon) in order from the incident direction (longitudinal direction) of Semiconductor 3d). The first semiconductor is for detecting blue light, the second semiconductor is for detecting green light, the third semiconductor is for detecting red light, and the fourth semiconductor is for detecting near-infrared light. The lengths and arrangements of the first semiconductor to the fourth semiconductor in the longitudinal direction are as shown in FIG.

In FIG. 17, the signal input unit 11 inputs a signal output from the pad 6 of the image sensor 1. The coefficient calculation unit 12 calculates a coefficient a _ij in the following equation (1) from the signal charge amount input by the signal input unit 11 and stores it in the coefficient information storage unit 16.

ここで、Ｂは入射光における青色光、Ｇは入射光における緑色光、Ｒは入射光における赤色光、ＩＲは入射光における近赤外光の信号電荷量であり、Ｘは第１半導体で検知された信号電荷量、Ｙは第２半導体で検知された信号電荷量、Ｚは第３半導体で検知された信号電荷量、Ｗは第４半導体で検知された信号電荷量とし、ａ_ijは素子ごとに決まる入射光
の分光特性を示す係数である。

Here, B is blue light in the incident light, G is green light in the incident light, R is red light in the incident light, IR is a signal charge amount of near infrared light in the incident light, and X is detected by the first semiconductor. Y is the signal charge amount detected by the second semiconductor, Y is the signal charge amount detected by the third semiconductor, W is the signal charge amount detected by the fourth semiconductor, and a _ij is the element It is a coefficient indicating the spectral characteristics of incident light determined for each.

  Formula (1) will be described in more detail. As described above, the signal charges detected in the depletion regions of the first semiconductor to the fourth semiconductor are X, Y, Z, and W, and the wavelengths of blue light, green light, red light, and near-infrared light in incident light. When the signal charge amounts corresponding to the components are B, G, R, and IR, the following relationship is established.

つまり、入射光における波長成分は、式（２）に｛ａ_ij｝^-1を掛けた式（１）により求めることができる。

That is, the wavelength component in the incident light can be obtained by Expression (1) obtained by multiplying Expression (2) by {a _ij } ⁻¹ .

A method for _obtaining the coefficient a _ij in the equations (1) and (2) will be described with reference to FIG. FIG. 19 shows a signal charge corresponding to the wavelength component of incident light converted in the PN junction region formed of the first semiconductor to the fourth semiconductor when the imaging device 1 is irradiated with uniform white light as incident light. The characteristics of the quantities (X, Y, Z, W) are shown. The signal charge amount on the vertical axis is an arbitrary unit, and the value can be freely set.

  As shown in FIG. 19, since the incident light is white light, it can be seen that various wavelength components are detected in each PN junction region. From the wavelength components thus detected, first, the wavelength on the horizontal axis is divided into a plurality of regions. The classification method can be arbitrarily set, but here, it corresponds to the wavelength range of blue light, green light, red light, and near infrared light, as shown in FIG. 1 wavelength region), 465 to 560 nm (second wavelength region), 560 to 760 nm (third wavelength region), and 760 nm to (fourth wavelength region). Further, the division may be made with the wavelength at the point where the curves of the signal charge amounts intersect as a boundary. In the case of FIG. 19, the wavelengths of the points where the curves intersect each other coincide with the wavelength ranges of the respective colors, but there are cases where the wavelengths do not necessarily coincide.

For each wavelength region thus _divided , a _ij is determined by performing the following calculation. a ₁₁ is an average value obtained by summing up signal charges detected in the depletion region of the first semiconductor in the first wavelength region, and a ₂₁ is detected in the depletion region of the second semiconductor in the first wavelength region. A ₃₁ is an average value obtained by aggregating the signal charge amounts detected in the depletion region of the third semiconductor in the first wavelength region, and a ₄₁ is The average value obtained by summing up the signal charge amounts detected in the depletion region of the fourth semiconductor in the first wavelength region is used.

Similarly, a ₁₂ is an average value obtained by summing up signal charge amounts detected in the depletion region of the first semiconductor in the second wavelength region, and a ₂₂ is a depletion region of the second semiconductor in the second wavelength region. A ₃₂ is an average value obtained by aggregating the signal charge amounts detected in the depletion region of the third semiconductor in the second wavelength region, and a _{32 42} is an average value obtained by summing up the signal charge amounts detected in the depletion region of the fourth semiconductor in the second wavelength region.

Similarly, a ₁₃ is the average value obtained by aggregating the signal charge amount detected by the depletion region of the first semiconductor in the third wavelength region, a ₂₃ is the depletion region of the second semiconductor in the third wavelength region A ₃₃ is an average value obtained by aggregating the signal charge amounts detected in the depletion region of the third semiconductor in the third wavelength region, ₄₃ is an average value obtained by summing up signal charge amounts detected in the depletion region of the fourth semiconductor in the third wavelength region.

Similarly, a ₁₄ is the average value obtained by aggregating the signal charge amount detected by the depletion region of the first semiconductor in the fourth wavelength range, a ₂₄ is the depletion region of the second semiconductor in the fourth wavelength region A ₃₄ is an average value obtained by aggregating the signal charge amounts detected in the depletion region of the third semiconductor in the fourth wavelength region, and a _{34 44} is an average value obtained by summing up signal charge amounts detected in the depletion region of the fourth semiconductor in the fourth wavelength region.

As described above, an average value obtained by totaling the signal charge amounts in the wavelength region may be calculated as the coefficient a _ij , or the average value of the maximum value and the minimum value in the wavelength region may be calculated as the coefficient a _ij. May be calculated as

Returning to FIG. 17, the signal component calculation unit 13 calculates the signal component of the wavelength in the incident light using the coefficient a _ij calculated by the coefficient calculation unit 12. FIG. 20 shows the calculation result. As shown in FIG. 20, by performing the calculation of Expression (1), the wavelength components of blue light, green light, red light, and near-infrared light are clarified, and accurate spectral characteristics of incident light are required. Here, since white light is used as incident light, ideal values of various wavelength components are obtained, and this is stored in the wavelength information storage unit 14 of FIG. 17 as a template. That is, the wavelength corresponding to each wavelength component of blue light, green light, red light, and near infrared light is stored.

In the wavelength determining unit 15, when unknown incident light is irradiated, the signal input unit 11 inputs the incident light signal, and the signal component calculation unit 13 uses the coefficient a _ij stored in the coefficient information storage unit 16. Read out and calculate the signal component of the wavelength in the incident light, the ratio of the signal charge amount corresponding to each wavelength of blue light, green light, red light and near infrared light in the obtained incident light, and wavelength information as a template The wavelength component information stored in the storage unit 14 is compared, and the corresponding wavelength is determined as the wavelength of the incident light. By determining the wavelength of the incident light, the color of the incident light can be specified.

  As described above, the wavelength determining unit 15 can determine the wavelength of the incident light, but the intensity of the incident light cannot be determined only by this processing. Therefore, the imaging apparatus 1 may be configured to include a light intensity calculation unit. The light intensity calculation unit can obtain the light intensity by using the total signal charge amount input by the signal input unit 11.

Next, the operation of the imaging apparatus according to the present embodiment will be described. The processing of the imaging apparatus here can be roughly divided into two. One is a first process for determining a coefficient a _ij indicating the spectral characteristic of incident light determined for each element and generating a template indicating the ratio of wavelength components from white light, and the other is an operation using the coefficient a _ij This is a second process for determining the wavelength of incident light from the result and template information. FIG. 21 is a flowchart showing the first process, and FIG. 22 is a flowchart showing the second process.

In FIG. 21, first, the signal input unit 11 inputs a white light signal output from the image sensor 1 (S211). The coefficient calculation unit 12 calculates the representative value of the signal charge amount (the average value of the signal charge amount or the average value of the maximum and minimum values of the signal charge amount) for each of the wavelength regions divided into a plurality as shown in FIG. (S212). The calculated representative value is stored in the coefficient information storage unit 16 as a coefficient a _ij indicating the spectral characteristic of incident light determined for each element (S213). The signal component calculation unit 13 calculates the signal component of the wavelength of white light using the calculated coefficient a _ij as shown in FIG. 20 (S214). The calculated signal component of the wavelength of white light is stored as a template in the wavelength information storage unit 14 (S215), and the first process is terminated.

In FIG. 22, first, the signal input unit 11 inputs a signal of incident light output from the image sensor 1 (S221). The signal component calculation unit 13 reads the coefficient a _ij from the coefficient information storage unit 16 and calculates the signal component of the wavelength in the incident light using the equation (1) (S222). The wavelength determination unit 15 compares the ratio of the signal component of the wavelength in the calculated incident light with the template information stored in the wavelength information storage unit 14 (S223), and determines the ratio of the signal component of the wavelength that matches the template. The corresponding wavelength is determined as the wavelength of the incident light (S224), and the second process is terminated.

  The above is the description of the operation of the imaging apparatus according to the present embodiment.

DESCRIPTION OF SYMBOLS 1 Image pick-up element 2 p-type silicon semiconductor substrate 3 n-type silicon semiconductor 3a Silicon semiconductor for blue light detection (n-type silicon semiconductor 3)
3b Green light detection silicon semiconductor (n-type silicon semiconductor 3)
3c Silicon semiconductor for detecting red light (n-type silicon semiconductor 3)
3d Silicon semiconductor for near-infrared light detection (n-type silicon semiconductor 3)
DESCRIPTION OF SYMBOLS 5 Conversion circuit part 6 Pad 7 Lens 8 Reflective material 10 Imaging device 11 Signal input part 12 Coefficient calculation part 13 Signal component calculation part 14 Wavelength information storage part 15 Wavelength determination part 16 Coefficient information storage part

Claims (14)

In an imaging device that photoelectrically converts light incident on a depletion region generated at a junction between a first conductivity type semiconductor substrate and a second conductivity type semiconductor,
The second conductivity type semiconductor, the inside of the first conductivity type semiconductor substrate, while being more disposed along the surface direction of the first conductivity type semiconductor substrate, extending the direction of incidence of the light as the longitudinal direction And
Laminating the first conductive semiconductor substrate on which the second conductive semiconductor is disposed in a plurality of layers;
A conversion circuit unit that performs processing for converting at least the electric charge output from the depletion region into an output signal adjacent to the other end of the second conductivity type semiconductor on the side opposite to the light incident side;
A pad portion disposed on an upper surface of the first conductivity type semiconductor substrate, adjacent to the conversion circuit portion, and electrically connected to the conversion circuit portion;
An image pickup device, wherein a distance between the conversion circuit portion and the pad portion is sequentially increased from an upper layer . In an imaging device that photoelectrically converts light incident on a depletion region generated at a junction between a first conductivity type semiconductor substrate and a second conductivity type semiconductor,
A plurality of the second conductivity type semiconductors are disposed in the first conductivity type semiconductor substrate along the surface direction of the first conductivity type semiconductor substrate, and the light incident direction extends in the longitudinal direction. And
A lens varying unit that varies the position of the lens on the light incident side in the longitudinal direction of the second conductive type semiconductor;
An imaging device characterized in that an imaging area is divided into a plurality of sections corresponding to a changed lens position, and imaging is performed for each of the divided sections . In an imaging device that photoelectrically converts light incident on a depletion region generated at a junction between a first conductivity type semiconductor substrate and a second conductivity type semiconductor,
A plurality of the second conductivity type semiconductors are disposed in the first conductivity type semiconductor substrate along the surface direction of the first conductivity type semiconductor substrate, and the light incident direction extends in the longitudinal direction. And
An imaging device comprising: a reflective material that reflects light transmitted through the second conductive type semiconductor at the other end of the second conductive type semiconductor opposite to one end on which light enters . The imaging device according to any one of claims 1 to 3,
In the depletion region formed by the first conductive type semiconductor substrate and the second conductive type semiconductor, the first conductive type semiconductor is located at the position of the side edge in the light incident direction of the first conductive type semiconductor substrate. imaging element characterized that you have been cut. The imaging device according to any one of claims 1 to 4,
The image pickup device, wherein the incident light is near infrared rays . The imaging device according to claim 5 ,
An image pickup device , wherein a length of the second conductivity type semiconductor in a longitudinal direction is equal to or longer than a penetration length of the near infrared ray with respect to the second conductivity type semiconductor . The imaging device according to any one of claims 1 to 4 ,
A plurality of the second conductivity type semiconductors are arranged in the longitudinal direction of the second conductivity type semiconductor, and each of the plurality of second conductivity type semiconductors is located at a position corresponding to the penetration length of the incident light with respect to the second conductivity type semiconductor. An image pickup device comprising a two-conductivity type semiconductor . The image pickup device according to claim 7 ,
The length of each of the plurality of second conductivity type semiconductors arranged in the longitudinal direction is arranged so as to increase sequentially from one end on the light incident side to the other end on the opposite side. An imaging device as a feature. The image sensor according to claim 8, wherein
Four second conductivity type semiconductors are disposed,
An image pickup device , wherein blue light, green light, red light, and near infrared light are photoelectrically converted in order from a light incident side . The imaging device according to claim 9,
An image pickup device, wherein a plurality of second conductive semiconductors arranged in a longitudinal direction have a length equal to or greater than a penetration length of each incident light into the second conductive semiconductor . An imaging apparatus using the imaging device according to any one of claims 7 to 10 ,
Four of the second conductivity type semiconductors are disposed, and the four second conductivity type semiconductors are sequentially designated as a first semiconductor, a second semiconductor, a third semiconductor, and a fourth semiconductor from the light incident side,
Wavelength information storage means for storing a wavelength corresponding to a charge amount ratio of a signal obtained by photoelectrically converting light incident on each depletion region formed by the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor. When,
Signal input means for inputting signal charges detected in the depletion regions of the four second-conductivity-type semiconductors;
Based on the signal charge amount of the signal charge input by the signal input means, signal component calculation means for calculating the signal charge amount of blue light, green light, red light and near infrared light in the incident light by the following equation:

(B is the blue light in the incident light, G is the green light in the incident light, R is the red light in the incident light, IR is the signal charge amount of the near infrared light in the incident light, and X is the depletion region of the first semiconductor. , Y is the signal charge detected in the depletion region of the second semiconductor, Z is the signal charge detected in the depletion region of the third semiconductor, and W is detected in the depletion region of the fourth semiconductor (A _ij is a coefficient indicating the spectral characteristic of incident light determined for each element.)
Based on the signal charge amount calculated by the signal component calculation means, the ratio of each signal charge amount is calculated, and the wavelength associated with the calculated signal charge amount ratio is read from the wavelength information storage means. An imaging apparatus comprising: wavelength determining means that determines the wavelength of the incident light. The imaging device according to claim 11 ,
Each signal detected in the depletion region of the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor when the coefficient indicating the spectral specification of the incident light determined for each element is white light. An imaging apparatus, wherein the charge amount is a representative value calculated for each of wavelength regions divided into a plurality. The imaging apparatus according to claim 12 ,
The representative value is an average calculated from a total value for each wavelength region divided into a plurality of signal charge amounts detected in the depletion regions of the first semiconductor, the second semiconductor, the third semiconductor, and the fourth semiconductor. An image pickup apparatus characterized by an average value calculated from a value or a total value of a maximum charge amount and a minimum charge amount . The imaging device according to any one of claims 11 to 13,
An image pickup apparatus comprising: a light intensity calculation unit that calculates the intensity of the incident light based on a ratio of each signal charge amount to a total charge amount in the signal charge amount calculated by the signal component calculation unit .

Images