JP2013211413A - Solid state image sensor and image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a discrepancy in photosensitivity caused by manufacturing errors between phase difference detection pixel pairs.SOLUTION: An image sensor comprises: a semiconductor substrate 60 in which a plurality of pixels separated from adjacent pixels by a pixel boundary portion 63 are formed in shape of a two-dimensional array on a light-receiving surface; a pupil dividing microlens 50, disposed every two adjacent pixels or every four most adjacent pixels, which turns the two adjacent pixels or the four most adjacent pixels into phase difference detection pixels; intermediate layers 65, 66 and 67 which are laminated between the pupil dividing microlens 50 and the semiconductor substrate 60; and an incident light scattering medium 70 which is disposed on an optical path linking the pixel boundary portion 63 of a plurality of phase difference detection pixels receiving incident light focused by the pupil dividing microlens 50 and the center position of the pupil dividing microlens 50 and in the intermediate layers.

Description

  The present invention relates to a solid-state imaging device and an imaging apparatus equipped with phase difference detection pixels, and in particular, solid-state imaging that detects a phase difference of incident light by a pupil division method in which a plurality of phase difference detection pixels share one microlens. The present invention relates to an element and an imaging device.

  FIG. 19 shows a solid-state imaging device in which one microlens is mounted on one pixel. The microlenses 1 and 2 of the adjacent two pixels collect incident light and enter the corresponding charge accumulation regions (photoelectric conversion regions) 3 and 4. Since the arrangement structure of the microlens 1 and the charge accumulation region 3 and the arrangement structure of the microlens 2 and the charge accumulation region 4 are the same structure, the detected charge amounts by the charge accumulation regions 3 and 4 are the same.

  On the other hand, as shown in FIG. 20, if one microlens 7 is shared by two adjacent charge storage regions 5 and 6, there is a difference in the detected charge amount between the two charge storage regions 5 and 6. Arise. This difference is a function of the phase difference amount. This is because one detected charge amount in the charge accumulation regions 5 and 6 corresponds to a signal amount when the subject is viewed with the right eye, and the other detected charge amount corresponds to a signal amount when the subject is viewed with the left eye. By detecting this phase difference amount, the distance to the subject can be calculated.

  A pixel that uses such a pupil division method to detect a phase difference is described in, for example, Patent Document 1 below, and has already been used as a sensor that detects a focus position to a subject.

  When manufacturing such a pair of phase difference detection pixels, it is necessary to accurately form the charge accumulation region 5 and the charge accumulation region 6 at symmetrical positions with respect to the center position of the microlens 7. For example, as shown in FIG. 21, if the center of the microlens 7 is positioned at the center between the charge storage region 5 and the charge storage region 6, as shown in FIG. And the light incident angle characteristics of the charge storage region 6 are the same. That is, the light receiving sensitivity characteristics V and VI of the charge storage regions 5 and 6 are symmetrical with respect to the incident angle with the light incident angle of 0 degree as the center.

  However, as shown in FIG. 23, if the center position 7a of the microlens 7 and the pixel boundary center position 8 of the charge storage regions 5 and 6 are shifted and are biased to one side, as shown in FIG. The light receiving sensitivities of both the charge accumulation regions 5 and 6 are biased. That is, when the incident angle is 0 degree, the light receiving sensitivity V of one charge storage region 5 is high, and the light receiving sensitivity VI of the other charge storage region 6 is low, resulting in a difference. This difference increases as the photographing lens is reduced.

  There is a difference in the light-receiving sensitivity characteristics of the phase difference detection pixel pair due to misalignment at the time of manufacturing. In the state shown in FIG. 24, subject light from a distance with no phase difference is incident on the phase difference detection pixel pair. However, there is a difference between the detection signal amounts. This becomes a problem when the phase difference amount is obtained by the difference in the detection signal amount.

  For this reason, it is required that the charge accumulation region of each pixel of the solid-state imaging device and the position of the microlens be manufactured with high precision by a fine processing technique. However, since recent solid-state imaging devices have become enormous, with 10 million or more pixels, highly accurate alignment is difficult.

  Therefore, conventionally, for example, as described in Patent Document 2 below, a difference in light receiving sensitivity due to misalignment during manufacturing is corrected by signal processing.

JP 2007-281296 A JP 2010-237401 A

  The misalignment at the time of manufacturing the solid-state image sensor is a fixed misalignment inherent to the solid-state image sensor. For this reason, if the characteristic deviation resulting from the misalignment is measured in advance, it can be dealt with by signal processing.

  However, a control unit mounted on an imaging apparatus such as a digital camera is not limited to phase difference detection processing, but various signals such as various image signal processing such as offset processing and gamma correction processing, data compression processing, and data transfer processing. Processing is in progress. Furthermore, in recent years, it has become common for digital cameras to be equipped with a high-speed continuous shooting function, and it is necessary to perform signal processing on each captured image during high-speed continuous shooting. That is, there is a demand for higher speed signal processing.

  For this reason, there is a high demand for the control unit of the digital camera to perform only necessary signal processing as much as possible to reduce the processing load and increase the processing speed. Therefore, it is desired to solve the characteristic deviation between the paired pixels caused by the misalignment at the time of manufacture by another method instead of correcting by the signal processing.

  An object of the present invention is to provide a solid-state imaging device and an imaging apparatus having a structure capable of eliminating a light receiving sensitivity characteristic deviation between phase difference detection pixel pairs caused by a positional deviation at the time of manufacture.

  The solid-state imaging device of the present invention includes a semiconductor substrate on a light receiving surface on which a plurality of pixels separated from adjacent pixels by a pixel boundary portion are formed in a two-dimensional array, and every two adjacent pixels or every four adjacent pixels. A pupil division microlens that is provided and uses the two adjacent pixels or the four adjacent pixels as phase difference detection pixels, an intermediate layer laminated between the pupil division microlens and the semiconductor substrate, and the pupil division Incident light scattering provided on an optical path connecting the pixel boundary portions of the plurality of phase difference detection pixels that receive incident light collected by the microlens and the center position of the pupil division microlens and in the intermediate layer With body.

  An image pickup apparatus according to the present invention includes any one of the solid-state image pickup elements described above.

  According to the present invention, it is possible to divide the light incident on the pixel boundary portion between the plurality of phase difference detection pixels through the center of the pupil division microlens into the phase difference detection pixels by equally dividing the light by the light scatterer. Become. As a result, the light reception sensitivity deviation between the respective phase difference detection pixels caused by the manufacturing error of the image sensor is corrected, and the phase difference amount can be detected with high accuracy.

1 is an external perspective view of an imaging apparatus according to an embodiment of the present invention. It is a functional block block diagram of the imaging device shown in FIG. It is a surface view of the image sensor shown in FIG. FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 3. It is the figure which looked at the incident light scatterer shown in FIG. 4 from the micro lens side. FIG. 5 is a characteristic diagram of a phase difference pixel pair in the embodiment of FIG. 4. FIG. 5 is an explanatory diagram of a manufacturing process of the image sensor according to the embodiment of FIG. 4. It is a cross-sectional schematic diagram of the image sensor which concerns on 2nd Embodiment of this invention. It is a cross-sectional schematic diagram of the image sensor which concerns on 3rd Embodiment of this invention. It is a cross-sectional schematic diagram of the image sensor which concerns on 4th Embodiment of this invention. It is a characteristic view of the phase difference pixel pair in embodiment of FIG. It is the surface schematic diagram of the image sensor which mounts one micro lens in the nearest 4 pixels, and makes it a phase difference detection pixel. It is the figure which looked at the incident light scatterer provided in the phase difference detection pixel of four adjacent pixels of FIG. 12 from the micro lens side. It is the surface schematic diagram of the image sensor which comprises all the pixels by a phase difference detection pixel pair. It is a surface schematic diagram of the image sensor which makes all the pixels a phase difference detection pixel per 4 pixels. It is a cross-sectional schematic diagram of the image sensor which concerns on the 5th Embodiment of this invention which gave the countermeasure against shading. It is an external appearance perspective view of the smart phone concerning another embodiment of an imaging device. It is a functional block block diagram of the smart phone of FIG. It is a cross-sectional schematic diagram of the image sensor of 1 pixel 1 micro lens. It is a cross-sectional schematic diagram of the phase difference detection pixel pair of 2 pixels 1 microlens. FIG. 21 is an ideal cross-sectional schematic diagram of the phase difference detection pixel pair of FIG. 20. It is a characteristic view of the phase difference detection pixel pair of FIG. FIG. 21 is a schematic cross-sectional view in the case where there is a misalignment between the microlens and the phase difference detection pixel in the phase difference detection pixel pair of FIG. 20. FIG. 24 is a characteristic diagram of the phase difference detection pixel pair in FIG. 23.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of an imaging apparatus (digital camera) 10 according to an embodiment of the present invention. The digital camera 10 includes a photographic lens 12 at the front of a rectangular casing 11. The taking lens 12 is housed in a retractable lens barrel 13. A shutter release button 14 is provided on the left shoulder portion of the housing 11. A liquid crystal display unit (LCD 16 in FIG. 2) that displays a captured image, a through image (live view image), a camera menu image, and the like is provided on the rear surface of the housing 11. A flash light emitting unit 44 is provided at the front of the right shoulder.

  FIG. 2 is a functional block configuration diagram of the digital camera shown in FIG. The digital camera 10 includes an image sensor (a CMOS image sensor in this embodiment) 21 provided on the back of the photographing lens 12 and a CPU (central processing unit) 22 that controls the digital camera 10 in an integrated manner.

  The CPU 22 is connected to the bus 23, and stores the frame memory 24, a signal processing unit (DSP) 25 that performs image processing, and captured image data compressed in JPEG format or the like in the external memory card 26. A card interface (I / F) 27, a display control unit 28 that performs display control of an LCD (liquid crystal display unit) 16 on the back of the camera, and an OSD signal generation unit 29 that generates OSD signals such as character information to be displayed on the LCD 16. Is connected.

  The CPU 22 is connected to a ROM 22a and a RAM 22b that store control programs and the like, and an operation unit 40 including a shutter release button 14 is connected. The digital camera 10 also drives the lens drive unit 41 that controls the focus lens position and the like of the photographing lens 12, the timing generator (TG) 42 that generates the drive timing signal of the image sensor 21, and the image sensor 21. A driver 43 and a flash control circuit 45 that performs light emission control of the light emitting unit 44 are provided, and these are instructed to be controlled by the CPU 22.

  The CPU 22 performs various control processes using the subordinate DSP 25 or the like. For example, a signal output from a phase difference detection pixel of an image sensor 21 having a structure that will be described in detail later is processed, the distance to the subject is calculated, the focus lens position of the photographing lens 12 is adjusted, and the subject is focused. The captured image is captured.

  FIG. 3 is a schematic diagram of the surface of the image sensor (solid-state imaging device) 21. In the image sensor 21 formed on the semiconductor substrate, each pixel (charge storage region: photoelectric conversion unit) is arranged in a two-dimensional array form, in the illustrated example, in a square lattice form. The three primary color R (red), G (green), and B (blue) color filters are arranged in a Bayer array with two pixels that are continuous in the horizontal direction as one unit. In other words, rows in which RRGGRRGG... And color filters are arranged and rows in which GGBBGGBBB... And color filters are arranged are alternately arranged.

  Of the pixels formed on the semiconductor substrate, the number of pixels on which the G filter is mounted is larger than the number of pixels on which the R filter and the B filter are mounted. For this reason, the pair pixel which exists in a discrete position among the two G filter mounting pixel pairs which continue in a horizontal direction is made into the phase difference detection pixel pair.

  The phase difference detection pixel pair of the present embodiment is formed by sharing a pupil-dividing microlens (on-chip lens) among the paired pixels. In FIG. 3, two pixels mounted with an elliptical microlens 50 constitute a phase difference detection pixel pair, and a pixel mounted with a microlens 51 indicated by a circle is a pixel that detects a normal captured image signal. In the normal pixel on which the microlens 51 is mounted, one charge accumulation region corresponds to one microlens 51 as in the pixel shown in FIG.

  FIG. 4 is a schematic cross-sectional view in the horizontal direction (IV-IV line position in FIG. 3) of the phase difference detection pixel pair on which the elliptical microlens 50 is mounted. On the p-type semiconductor substrate 60, two pairs of photoelectric conversion regions (charge storage regions: n regions) 61 and 62 are provided adjacent to each other with an element isolation band 63 interposed therebetween. A transparent insulating film 64 is laminated on the surface of the semiconductor substrate 60, a transparent flattening layer (insulating layer) 65 is further laminated thereon, and a color filter layer 66 is further laminated thereon. An elliptical microlens 50 shown in FIG. 3 is provided on the color filter layer 66 through a planarizing layer 67.

  In the example shown in the drawing, an intermediate layer between the insulating film 64 and the microlens 50 formed on the semiconductor substrate is formed by planarization layers 65 and 67 and a color filter layer 66.

  In the solid-state imaging device of this embodiment, an incident light scatterer 70 is provided in the planarization layer 65. The incident light scatterer 70 includes a boundary portion between the two pixels (charge storage regions) 61 and 62 (in the example of FIG. 4, a portion where the element isolation band 63 is provided), and the center position of the microlens 50 (the zenith portion). ). The incident light scatterer 70 is formed, for example, by embedding a material having a lower refractive index than the surrounding material. The incident light scatterer 70 is provided with a width approximately equal to or slightly wider than the width of the boundary portion 63 and covers the boundary portion 63.

  Assume that a misalignment has occurred between the manufacturing position of the microlens 50 and the manufacturing positions of the two paired pixels 61 and 62. The example of FIG. 4 shows a state where the lens 50 is manufactured with a deviation between the center position 71 of the lens 50 and the center position 72 of the pixel boundary 63. Even in the presence of such misalignment, in the solid-state imaging device 21 of the present embodiment, the light incident on the boundary portion between the pixels 61 and 62 is diffused by being scattered by the incident light scatterer 70. The As a result, the light incident on the boundary portion is divided and incident on the two pixels 61 and 62 by approximately ½.

  FIG. 5 is a view of the incident light scatterer 70 as viewed from the light incident side (microlens 50 side). The portion hatched in FIG. 5 is the incident light scatterer 70. In FIG. 5A, since the incident light of the microlens 50 is collected at the central portion (the central portion of the boundary portion 63), it is formed in a disk shape that covers the central portion. In FIG. 5B, an incident light scatterer 70 is provided along the boundary portion 63 between the pixels 61 and 62. Either incident light scatterer 70 may be used, and the one that is easy to manufacture is adopted.

  FIG. 6 is a characteristic diagram when a misalignment occurs between the microlens 50 and the pixels 61 and 62 and when an incident light scatterer 70 is provided. The vertical axis represents the light receiving sensitivity of each of the pixels 61 and 62, and the horizontal axis represents the light incident angle. As can be seen from the comparison with FIG. 24, the incident angle positions at the peak sensitivities of the pixels 61 and 62 are the same as those in FIG. However, due to the influence of the incident light scatterer 70, the light incident on the scatterer 70 is distributed to each of the pixels 61 and 62 at an incident angle of 0 degree, and the light receiving sensitivity of each of the pixels 61 and 62 is substantially the same. It becomes.

  That is, according to the present embodiment, it can be seen that there is almost no difference in the amount of detection signal between the pair of pixels 61 and 62 even if misalignment occurs during manufacturing. For this reason, when there is a difference in the detection signal amount between the pair of pixels 61 and 62, this difference is caused by the phase difference amount, and the phase difference amount, that is, the distance to the subject can be calculated with high accuracy. It becomes possible.

  FIG. 7 is a manufacturing process diagram of the incident light scatterer 70. After the charge storage regions 61 and 62 and the element isolation band (pixel boundary portion) 63 are manufactured on the semiconductor substrate 60 and the surface of the semiconductor substrate 60 is covered with the insulating film 64, a high refractive index material layer such as SiN is formed in Step I. 65 is laminated on the insulating film 64. In the next step II, the portion of the high refractive index material layer 65 corresponding to the upper portion of the pixel boundary 63 is etched to provide a recess 74.

In the next step III, a low refractive material such as SiO ₂ is laminated so that the recess 74 is filled, and in the next step IV, the surface is flattened. In step V, a high refractive index material layer 65 is laminated on the surface. Further, the color filter layer 66, the flattening layer 67, and the microlens layer shown in FIG. 4 are provided to manufacture the solid-state imaging device 21.

  When forming a film by a semiconductor device manufacturing technique, it is more difficult to manufacture a homogeneous film without a gap than to manufacture a rough heterogeneous film in which a gap is mixed. For this reason, semiconductor device manufacturing techniques have been developed so that homogeneous films can be manufactured.

However, it is preferable that the scatterer 70 of the present embodiment is in a state in which a large number of gaps enter and the incident light is easily scattered. Therefore, when the incident light scatterer 70 is manufactured, the setting of the SiO ₂ film forming condition in Step III of FIG. 7 is set so as to be shifted from the film forming condition of the homogeneous film. Thereby, the incident light scatterer 70 can be manufactured easily.

  FIG. 8 is a schematic cross-sectional view of a phase difference detection pixel pair according to the second embodiment of the present invention. Compared with the embodiment of FIG. 4, a difference is that an inner lens 75 common to both the pixels 61 and 62 is provided in the planarization layer 65.

  When such an inner lens 75 is provided, alignment of the center position of the inner lens 75, the center position of the microlens (top lens) 50, and the center position of the pixel boundary 63 becomes more difficult. However, as in the embodiment shown in FIG. 8, by providing the incident light scatterer 70, the incident light incident on the pixel boundary 63 can be converted into two phase differences without performing alignment with high accuracy. It becomes possible to distribute to the detection pixels 61 and 62.

  In the example of FIG. 8, the incident light scatterer 70 is provided below the inner lens 75 (on the charge accumulation region side), but may be provided above the inner lens 75 (on the top lens 50 side). It is also possible to provide the color filter layer 66 or the planarizing layer 67 thereon.

  FIG. 9 is a schematic cross-sectional view of a phase difference detection pixel pair according to the third embodiment of the present invention. In the embodiment of FIG. 8, the common inner lens 75 is provided for the phase difference detection pixels 61 and 62, but in this embodiment, individual inner lenses 76 and 77 are provided for the phase difference detection pixels 61 and 62. An incident light scatterer 70 is provided between the inner lenses 76 and 77 and above the pixel boundary 63.

  As a result, even in this embodiment, even if misalignment occurs between the microlens (top lens) 50, the inner lenses 76 and 77, and the pixels (charge storage regions) 61 and 62, the light incident on the pixel boundary 63 is obtained. Can be divided into approximately two equal parts and distributed to the pixels 61 and 62.

  Also in this embodiment, the incident light scatterer 70 can be provided below the inner lenses 76 and 77.

  FIG. 10 is a schematic cross-sectional view of a phase difference detection pixel pair according to the fourth embodiment of the present invention. The configuration is almost the same as that of the embodiment of FIG. 4, and the only difference is that the zenith portion 50 a of the microlens 50 is made flat. Of course, an inner lens may be provided as in the embodiment of FIGS.

  By flattening the zenith portion 50a as in the present embodiment, the circle of confusion caused by the microlens 50 spreads, and even this alone, the light passing through the center of the lens 50 is blurred and is incident on the pixels 61 and 62 substantially evenly. . In this embodiment, since the incident light scatterer 70 is further provided above the pixel boundary 63, the light passing through the lens center is further divided into two equal parts and distributed to the pixels 61 and 62.

  FIG. 11 is a characteristic diagram in the fourth embodiment. Compared to the characteristic diagram of FIG. 6, the light receiving sensitivity of the pixel 61 and the light receiving sensitivity of the pixel 62 at the incident angle of 0 degrees are substantially equal. As a result, when a difference occurs in the detection signal amounts of the pixels 61 and 62, it can be seen that this difference is caused only by the phase difference.

  In the embodiment described above, the phase difference detection pixels are paired with two adjacent pixels, and one microlens is mounted in common. However, for example, as shown in FIG. 12, it is possible to mount one microlens 80 on the four adjacent pixels, and use the four pixels as phase difference detection pixels in the horizontal and vertical directions. Of course, the colors of the color filters mounted on these four pixels are the same color. For example, if the nearest four pixels are taken as one unit and the color filters are arranged in a Bayer array, the four pixels can be used as phase difference detection pixels.

  In this way, when one common microlens 80 is mounted on the four adjacent pixels, as shown in FIG. 13A, it is only necessary to provide the disc-shaped incident light scatterer 70 only at the central portion. Alternatively, as shown in FIG. 13B, a cross-shaped incident light scatterer 70 may be provided at a cross-shaped boundary portion that partitions the four adjacent pixels. The cross-sectional shape of the phase difference detection pixel pair and the position where the incident light scatterer 70 is provided are the same as those in FIGS. 4, 8, 9, and 10. As a result, the light that passes through the center of the microlens 80 and enters the pixel boundary at the center of the four adjacent pixels is divided into approximately four equal parts by the scatterer 70 and is allocated to each phase difference detection pixel.

  In the above-described embodiment, the phase difference detection pixel pair provided on the light receiving surface of the image sensor 21, that is, a part of the imaging surface for capturing the subject image is described, but the phase difference provided separately from the image sensor 21. An incident light scatterer may be provided in a sensor dedicated to detection.

  14 and 15 show an example in which all pixels formed on the light receiving surface of the image sensor 21 are phase difference detection pixels. In FIG. 14, the microlens 50 is shared by using two adjacent pixel pairs as a phase difference detection pixel pair, and in FIG. 15, the microlens 80 is shared by using four adjacent pixels as a phase difference detection pixel.

  If incident light from a subject is received by each phase difference detection pixel and a subject image is generated from each detection signal, a stereoscopic image of the subject can be captured as described in, for example, Japanese Patent Application Laid-Open No. 2011-15820.

  FIG. 16 is a schematic cross-sectional view of an image sensor according to the fifth embodiment of the present invention. In the image sensor, the sensitivity of the peripheral pixels is reduced with respect to the central pixel. Therefore, as described in, for example, JP-A-1-213079 and JP-A-2007-201090, the microlens formation position May be shifted toward the center of the image sensor with respect to the corresponding charge accumulation region formation position.

  An example in which the incident light scatterer according to the above-described embodiment is provided in an image sensor to which such countermeasures have been taken will be described. Incident light from the subject passing through the photographing lens 12 in FIG. 1 is collected by the photographing lens 12 and then spreads and enters the image sensor 21.

  Incident light enters the pixel near the center of the image sensor 21 substantially perpendicularly. On the other hand, incident light is incident obliquely on the peripheral pixels. Therefore, the microlens 50L is formed so as to be shifted in the center direction on the right side with respect to the left peripheral pixels 61L and 62L shown in the drawing. Conversely, the microlens 50R is formed so as to be shifted in the center direction on the left side with respect to the right peripheral pixels 61R and 62R.

  For the pixels in the central region of FIG. 16, the embodiments described in FIGS. 4, 8, 9, and 10 can be applied as they are. On the other hand, for the left peripheral pixel and the right peripheral pixel, the microlenses 50L and 50R are formed at positions shifted from the vertical upper positions of the respective phase difference detection pixels, so that the incident light scatterers 70L and 70R are formed. The position needs to be slightly shifted from the position described in the above embodiment.

  The obliquely incident light incident on the center position (the zenith portion position) of the microlenses 50R and 50L travels obliquely straight without being affected by the lens focusing effect. This optical path is indicated by dotted lines 81R and 81L. Dotted lines 81R and 81L correspond to the incident angle of 0 degrees in FIGS. 6 and 11 in the peripheral pixels.

  When the microlens 50R (50L) and the phase difference detection pixels 61R and 62R are manufactured by positioning, the position where the dotted line 81R (81L) advances coincides with the center position of the pixel boundary 63R (63L). Will be manufactured.

  An incident light scatterer 70R (70L) is provided in the same manner as in the above-described embodiment in order to compensate for the light receiving sensitivity deviation between the paired pixels when the positional deviation occurs during the manufacturing. The incident light scatterers 70R and 70L are provided at positions overlapping the oblique dotted lines 81R and 81L in the peripheral pixels.

  As long as the incident light scatterer 70R (70L) is provided at a position close to the pixel boundary 63R (63L), it may be provided immediately above the pixel boundary 63R (63L), as in the above embodiment. However, when the scatterer 70 is provided on the upper side of the inner lens 75 or the color filter layer 66 in FIG. 8, that is, when the scatterer 70 is provided at a position away from the pixel boundary 63R (63L), a dotted line 81R (81L) is provided. ) It is necessary to provide on. That is, it is necessary to provide on the line (= line corresponding to an incident angle of 0 degree) connecting the center position (zenith part) of the microlens and the pixel boundary position.

  Note that the embodiments shown in FIGS. 4, 8, 9, 10, and 16 described above are for the back-illuminated MOS solid-state imaging device 21, and therefore the wiring layer and the like are included in the intermediate layer 65 shown in the figure. Not provided. Therefore, although the incident light scatterer 70 can be easily manufactured, the above-described embodiment can be applied to a surface irradiation type, that is, an image sensor in which a wiring layer is provided in the intermediate layer 65. Further, the present invention is not limited to the MOS type and can be applied to a CCD type image sensor.

  As described above, the digital camera has been described as the embodiment of the photographing apparatus of the present invention, but the configuration of the photographing apparatus is not limited to this. As another imaging device of the present invention, for example, a built-in type or an external type PC camera or a portable terminal device having a shooting function as described below can be used.

  Examples of the portable terminal device that is an embodiment of the photographing apparatus of the present invention include a mobile phone, a smartphone, a PDA (Personal Digital Assistants), and a portable game machine. Hereinafter, a smartphone will be described as an example, and will be described in detail with reference to the drawings.

  FIG. 17 shows the appearance of a smartphone 200 that is an embodiment of the photographing apparatus of the present invention. A smartphone 200 illustrated in FIG. 17 includes a flat housing 201, and a display input in which a display panel 202 as a display unit and an operation panel 203 as an input unit are integrated on one surface of the housing 201. Part 204 is provided. Such a casing 201 includes a speaker 205, a microphone 206, an operation unit 207, and a camera unit 208. Note that the configuration of the housing 201 is not limited thereto, and for example, a configuration in which the display unit and the input unit are independent, or a configuration having a folding structure or a slide mechanism can be employed.

  FIG. 18 is a block diagram showing a configuration of the smartphone 200 shown in FIG. As shown in FIG. 18, the main components of the smartphone include a wireless communication unit 210, a display input unit 204, a call unit 211, an operation unit 207, a camera unit 208, a storage unit 212, and an external input / output unit. 213, a GPS (Global Positioning System) receiving unit 214, a motion sensor unit 215, a power supply unit 216, and a main control unit 220. As a main function of the smartphone 200, a wireless communication function for performing mobile wireless communication via a base station device BS (not shown) and a mobile communication network NW (not shown) is provided.

  The radio communication unit 210 performs radio communication with the base station apparatus BS accommodated in the mobile communication network NW according to an instruction from the main control unit 220. Using this wireless communication, transmission and reception of various file data such as audio data and image data, e-mail data, and reception of Web data and streaming data are performed.

  The display input unit 204 controls the main control unit 220 to display images (still images and moving images), character information, and the like to visually transmit information to the user and to detect user operations on the displayed information. A so-called touch panel, which includes a display panel 202 and an operation panel 203.

  The display panel 202 uses an LCD (Liquid Crystal Display), an OELD (Organic Electro-Luminescence Display), or the like as a display device. The operation panel 203 is a device on which an image displayed on the display surface of the display panel 202 is placed so as to be visible, and detects one or a plurality of coordinates operated by a user's finger or stylus. When this device is operated with a user's finger or stylus, a detection signal generated due to the operation is output to the main control unit 220. Next, the main control unit 220 detects an operation position (coordinates) on the display panel 202 based on the received detection signal.

  As shown in FIG. 17, the display panel 202 and the operation panel 203 of the smartphone 200 exemplified as an embodiment of the photographing apparatus of the present invention integrally constitute a display input unit 204. The arrangement 203 covers the display panel 202 completely. When such an arrangement is adopted, the operation panel 203 may have a function of detecting a user operation even in an area outside the display panel 202. In other words, the operation panel 203 includes a detection area (hereinafter referred to as a display area) for an overlapping portion that overlaps the display panel 202 and a detection area (hereinafter, a non-display area) for an outer edge portion that does not overlap the other display panel 202. May be included).

  Note that the size of the display area and the size of the display panel 202 may be completely matched, but it is not always necessary to match them. In addition, the operation panel 203 may include two sensitive areas of the outer edge portion and the other inner portion. Further, the width of the outer edge portion is appropriately designed according to the size of the housing 201 and the like. Furthermore, examples of the position detection method employed in the operation panel 203 include a matrix switch method, a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, a capacitance method, and the like. You can also

  The call unit 211 includes a speaker 205 and a microphone 206, converts user's voice input through the microphone 206 into voice data that can be processed by the main control unit 220, and outputs the voice data to the main control unit 220. 210 or the audio data received by the external input / output unit 213 is decoded and output from the speaker 205. As shown in FIG. 17, for example, the speaker 205 can be mounted on the same surface as the display input unit 204 and the microphone 206 can be mounted on the side surface of the housing 201.

  The operation unit 207 is a hardware key using a key switch or the like, and receives an instruction from the user. For example, as illustrated in FIG. 17, the operation unit 207 is mounted on the side surface of the housing 201 of the smartphone 200 and is turned on when pressed with a finger or the like, and turned off when the finger is released with a restoring force such as a spring. It is a push button type switch.

  The storage unit 212 includes a control program and control data of the main control unit 220, application software, address data that associates the name and telephone number of a communication partner, transmitted / received e-mail data, Web data downloaded by Web browsing, The downloaded content data is stored, and streaming data and the like are temporarily stored. The storage unit 212 includes an internal storage unit 217 built in the smartphone and an external storage unit 218 having a removable external memory slot. Each of the internal storage unit 217 and external storage unit 218 constituting the storage unit 212 includes a flash memory type, a hard disk type, a multimedia card micro type, a multimedia card micro type, This is realized using a storage medium such as a card type memory (for example, MicroSD (registered trademark) memory), a RAM (Random Access Memory), a ROM (Read Only Memory), or the like.

  The external input / output unit 213 serves as an interface with all external devices connected to the smartphone 200, and communicates with other external devices (for example, universal serial bus (USB), IEEE 1394, etc.) or a network. (For example, the Internet, wireless LAN, Bluetooth (registered trademark), RFID (Radio Frequency Identification), infrared communication (Infrared Data Association: IrDA) (registered trademark), UWB (Ultra Wideband) (registered trademark), ZigBee ( ZigBee) (registered trademark, etc.) for direct or indirect connection.

  As an external device connected to the smartphone 200, for example, a wired / wireless headset, a wired / wireless external charger, a wired / wireless data port, a memory card connected via a card socket, a SIM (Subscriber), and the like. Identity Module Card) / UIM (User Identity Module Card) card, external audio / video equipment connected via audio / video I / O (Input / Output) terminal, external audio / video equipment connected wirelessly, yes / no There are a wirelessly connected smartphone, a wired / wireless personal computer, a wired / wireless PDA, a wired / wireless personal computer, an earphone, and the like. The external input / output unit 213 transmits data received from such an external device to each component inside the smartphone 200, or allows the data inside the smartphone 200 to be transmitted to the external device. Can do.

  The GPS receiving unit 214 receives GPS signals transmitted from the GPS satellites ST1 to STn in accordance with instructions from the main control unit 220, executes positioning calculation processing based on the received GPS signals, and calculates the latitude of the smartphone 200. Detect the position consisting of longitude and altitude. When the GPS reception unit 214 can acquire position information from the wireless communication unit 210 or the external input / output unit 213 (for example, a wireless LAN), the GPS reception unit 214 can also detect the position using the position information.

  The motion sensor unit 215 includes a triaxial acceleration sensor, for example, and detects the physical movement of the smartphone 200 in accordance with an instruction from the main control unit 220. By detecting the physical movement of the smartphone 200, the moving direction and acceleration of the smartphone 200 are detected. The detection result is output to the main control unit 220.

  The power supply unit 216 supplies power stored in a battery (not shown) to each unit of the smartphone 200 in accordance with an instruction from the main control unit 220.

  The main control unit 220 includes a microprocessor, operates according to a control program and control data stored in the storage unit 212, and controls each unit of the smartphone 200 in an integrated manner. In addition, the main control unit 220 includes a mobile communication control function that controls each unit of the communication system and an application processing function in order to perform voice communication and data communication through the wireless communication unit 210.

  The application processing function is realized by the main control unit 220 operating according to application software stored in the storage unit 212. Application processing functions include, for example, an infrared communication function that controls the external input / output unit 213 to perform data communication with the opposite device, an e-mail function that transmits and receives e-mails, and a web browsing function that browses web pages. .

  Further, the main control unit 220 has an image processing function such as displaying video on the display input unit 204 based on image data (still image or moving image data) such as received data or downloaded streaming data. The image processing function is a function in which the main control unit 220 decodes the image data, performs image processing on the decoding result, and displays an image on the display input unit 204.

  Further, the main control unit 220 executes display control for the display panel 202 and operation detection control for detecting a user operation through the operation unit 207 and the operation panel 203. By executing the display control, the main control unit 220 displays an icon for starting application software, a software key such as a scroll bar, or a window for creating an e-mail. Note that the scroll bar refers to a software key for accepting an instruction to move the display portion of a large image that does not fit in the display area of the display panel 202.

  In addition, by executing the operation detection control, the main control unit 220 detects a user operation through the operation unit 207 or accepts an operation on the icon or an input of a character string in the input field of the window through the operation panel 203. Or a display image scroll request through a scroll bar.

  Further, by executing the operation detection control, the main control unit 220 causes the operation position with respect to the operation panel 203 to overlap with the display panel 202 (display area) or other outer edge part (non-display area) that does not overlap with the display panel 202. And a touch panel control function for controlling the sensitive area of the operation panel 203 and the display position of the software key.

  The main control unit 220 can also detect a gesture operation on the operation panel 203 and execute a preset function in accordance with the detected gesture operation. Gesture operation is not a conventional simple touch operation, but an operation that draws a trajectory with a finger or the like, designates a plurality of positions at the same time, or combines these to draw a trajectory for at least one of a plurality of positions. means.

  The camera unit 208 is a digital camera that performs electronic photography using an imaging device such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge-Coupled Device). In addition, the camera unit 208 converts image data obtained by imaging into compressed image data such as JPEG (Joint Photographic coding Experts Group) under the control of the main control unit 220, and records it in the storage unit 212. The data can be output through the output unit 213 and the wireless communication unit 210. In the smartphone 200 shown in FIG. 17, the camera unit 208 is mounted on the same surface as the display input unit 204, but the mounting position of the camera unit 208 is not limited to this, and the camera unit 208 may be mounted on the back surface of the display input unit 204. Alternatively, a plurality of camera units 208 may be mounted. When a plurality of camera units 208 are installed, the camera unit 208 used for shooting can be switched to perform shooting alone, or a plurality of camera units 208 can be used for shooting simultaneously.

  The camera unit 208 can be used for various functions of the smartphone 200. For example, an image acquired by the camera unit 208 can be displayed on the display panel 202, or the image of the camera unit 208 can be used as one of operation inputs of the operation panel 203. Further, when the GPS receiving unit 214 detects a position, the position can be detected with reference to an image from the camera unit 208. Furthermore, referring to the image from the camera unit 208, the optical axis direction of the camera unit 208 of the smartphone 200 is determined without using the triaxial acceleration sensor or in combination with the triaxial acceleration sensor. It is also possible to determine the current usage environment. Of course, the image from the camera unit 208 can also be used in the application software.

  In addition, the position information acquired by the GPS receiver 214 to the image data of the still image or the moving image, the voice information acquired by the microphone 206 (the text information may be converted into voice information by the main control unit or the like), Posture information and the like acquired by the motion sensor unit 215 can be added and recorded in the recording unit 212, or output through the input / output unit 213 and the wireless communication unit 210.

  The solid-state imaging device according to the embodiment described above includes a semiconductor substrate in which a plurality of pixels separated from adjacent pixels by a pixel boundary portion are formed in a two-dimensional array on the light receiving surface, and every two adjacent pixels or the nearest four pixels. A pupil division microlens that is provided for each pixel and uses the adjacent two pixels or the nearest four pixels as a phase difference detection pixel, an intermediate layer laminated between the pupil division microlens and the semiconductor substrate, Provided on the optical path connecting the pixel boundary portions of the plurality of phase difference detection pixels that receive the incident light collected by the pupil division microlens and the center position of the pupil division microlens and in the intermediate layer And an incident light scatterer.

  Further, the incident light scatterer of the solid-state imaging device of the embodiment is provided at least in the same width as the width of the pixel boundary portion.

  Further, the incident light scatterer of the solid-state imaging device according to the embodiment is formed by embedding a material having a refractive index lower than that of the intermediate layer in the intermediate layer.

  In the solid-state imaging device according to the embodiment, an inner lens is provided on the pupil division microlens side or the semiconductor substrate side of the incident light scatterer.

  In the solid-state imaging device according to the embodiment, a common inner lens is provided for a plurality of phase difference detection pixels that receive incident light collected by the one pupil division microlens. .

  In the solid-state imaging device of the embodiment, an inner lens is provided for each of a plurality of phase difference detection pixels that receive incident light collected by the one pupil division microlens.

  In the solid-state imaging device of the embodiment, the zenith portion of the pupil-dividing microlens is formed flat.

  In addition, the solid-state imaging device of the embodiment is characterized in that the solid-state imaging device is a backside illumination type.

  Further, an imaging apparatus according to the embodiment is characterized by mounting any one of the solid-state imaging elements described above.

  According to the embodiment described above, the light incident on the pixel boundary between the plurality of phase difference detection pixels through the center of the pupil division microlens is equally divided by the light scatterer and distributed to each phase difference detection pixel. Is possible. As a result, the light reception sensitivity deviation between the respective phase difference detection pixels caused by the manufacturing error of the image sensor is corrected, and the phase difference amount can be detected with high accuracy.

  In the image sensor (solid-state imaging device) according to the present invention, since the incident light scatterer is provided on the boundary of the phase difference detection pixel pair, the imaging device can detect the phase difference with high accuracy and performs AF processing of the phase difference detection method. It is also useful when applied to a monocular 3D camera or the like.

10,200 Imaging device 20 CPU
21 Image sensor (solid-state image sensor)
50,80 micro lens (on-chip lens)
60 Semiconductor substrate 61, 62 Phase difference detection pixel (charge storage region) pair 63 Pixel boundary 65 Flattening layer (intermediate layer)
70, 71R, 71L Incident light scatterers 75, 76, 77 Inner lenses 81L, 81R Optical path of obliquely incident light

Claims (9)

  On the light receiving surface, a plurality of pixels separated from adjacent pixels by a pixel boundary are formed in a two-dimensional array, and are provided for every two adjacent pixels or every four adjacent pixels. A pupil-dividing microlens that uses four adjacent pixels as phase difference detection pixels, an intermediate layer that is laminated between the pupil-dividing microlens and the semiconductor substrate, and an incident light that is collected by the pupil-dividing microlens A solid-state imaging device comprising: an incident light scatterer provided on an optical path connecting the pixel boundary portions of the plurality of phase difference detection pixels that receive light and the center position of the pupil division microlens and in the intermediate layer.   2. The solid-state imaging device according to claim 1, wherein the incident light scatterer is provided at least in the same width as a width of the pixel boundary portion.   3. The solid-state imaging device according to claim 1, wherein the incident light scatterer is formed by embedding a material having a refractive index lower than that of the intermediate layer in the intermediate layer.   4. The solid-state image pickup device according to claim 1, wherein an inner lens is provided on the pupil-dividing microlens side or the semiconductor substrate side of the incident light scatterer. .   5. The solid-state imaging device according to claim 4, wherein one common inner lens is provided for a plurality of phase difference detection pixels that receive incident light condensed by the one pupil-dividing microlens. element.   5. The solid-state imaging device according to claim 4, wherein an inner lens is provided for each of a plurality of phase difference detection pixels that receive incident light collected by the one pupil division microlens.   7. The solid-state imaging device according to claim 1, wherein a zenith portion of the pupil-dividing microlens is formed flat. 8.   The solid-state imaging device according to any one of claims 1 to 7, wherein the solid-state imaging device is a backside illumination type.   The imaging device carrying the solid-state image sensor of any one of Claim 1 thru | or 8.

Images