JP2011009365A - Solid-state image sensor and method of fabricating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make uniform the characteristics of each pixel in a solid-state image sensor where the positions of the openings are not spaced equally.SOLUTION: The solid-state image sensor 11 has openings which are not spaced equally in the row direction for the photodiodes 2 arranged at equal intervals. An on-chip lens L1A (L1B) located substantially in the center of the light receiving surface of the solid-state image sensor 11 and corresponding to the photodiode 2 is arranged so that the center L1C when viewed from right above overlaps the center O1C (O2C) of the opening O1 (O2) when viewed from right above. The on-chip lenses L1A and L1B are arranged by applying small scaling to the array pitch of the photodiodes 2 from the center of the light receiving surface of the solid-state image sensor 11 toward the periphery thereof, with reference to the position where the center LC of the on-chip lens overlaps the centers O1C, O2C of the corresponding openings O1, O2.

Description

  The present invention relates to a solid-state imaging device and a manufacturing method thereof, and more particularly, to a solid-state imaging device in which positions of openings are arranged at unequal intervals and a manufacturing method thereof.

  As a result of realizing high integration, there is known a solid-state imaging device having a structure in which the positions of the light receiving portions (openings) of each pixel are not arranged at equal intervals. However, when the apertures of the pixels are not uniform, the light collected by the microlenses is not the same between the pixels, and there is a problem that false colors and shading occur.

  With respect to such problems, Patent Document 1 proposes a solid-state imaging device in which the shape of the condenser lens is asymmetrical with respect to each pixel having openings that are not arranged at equal pitches. According to this technology, it is possible to suppress spurious signals while improving the integration density.

JP-A-8-32043

  However, the condenser lens described in Patent Document 1 has a problem that it is difficult to control manufacturing variations. Another problem is that it is difficult to scale the optical layer in the chip surface.

  The present invention has been made in view of such circumstances, and provides a solid-state imaging device in which the characteristics of each pixel are uniform and a method for manufacturing the same even if the positions of the openings are arranged at unequal intervals. The purpose is to do.

  In order to achieve the above object, the solid-state imaging device according to claim 1 is a photoelectric conversion region that converts received light into a signal charge, and is arranged in two-dimensionally at equal intervals in a row direction and a column direction, A plurality of photoelectric conversion regions each separated by a pixel separation region, and a charge for transferring the signal charges of the read photoelectric conversion regions for the two columns in the column direction, every two columns of the plurality of photoelectric conversion regions A transfer region, a first light-shielding portion formed on the pixel isolation region, and a second light-shielding portion formed on the charge transfer region, the first light-shielding portion being wider than the first light-shielding portion. A plurality of openings formed by two light-shielding portions, the first light-shielding portion, and the second light-shielding portion, and the plurality of photoelectric conversion regions are formed with unequal intervals in the row direction. Multiple openings corresponding to each and the received light A plurality of on-chip lens for condensing in the photoelectric conversion region to respond, characterized in that a distributed multiple on-chip lens according to the position of the corresponding opening.

  According to the first aspect of the present invention, since the on-chip lens is arranged according to the position of the corresponding opening, the characteristics of each pixel can be obtained even when the positions of the openings are arranged at unequal intervals. Can be made uniform.

  According to a second aspect of the present invention, in the solid-state imaging device according to the first aspect, in the photoelectric conversion region located at a substantially central portion of the plurality of photoelectric conversion regions arranged in two dimensions, the photoelectric conversion region corresponds to the photoelectric conversion region. The on-chip lens is arranged such that the center of the on-chip lens and the center of the opening corresponding to the photoelectric conversion region are aligned.

  Thereby, an on-chip lens can be appropriately arranged according to the position of the opening.

  According to a third aspect of the present invention, in the solid-state imaging device according to the second aspect, the plurality of on-chip lenses have a position where the center of each on-chip lens coincides with the center of the opening corresponding to the on-chip lens. It is characterized by being arranged scaled according to the distance from the on-chip lens corresponding to the photoelectric conversion region located at the substantially central portion as a reference.

  Thereby, an on-chip lens can be appropriately arranged according to the position of the opening.

  According to a fourth aspect of the present invention, in the solid-state imaging device according to any one of the first to third aspects, between the on-chip lens and each photoelectric conversion region corresponding to the received light, the received light and the corresponding photoelectric An intra-layer lens for condensing light in the conversion region is provided, and the intra-layer lens is arranged so that its center coincides with the center of the corresponding opening.

  Thereby, even if it is a case where an inner lens is used, the characteristic of each pixel can be made uniform.

  According to a fifth aspect of the present invention, in the solid-state imaging device according to the fourth aspect, the intra-layer lens is an upward convex lens when viewed from the upstream side of the optical path.

  Thereby, the light received appropriately can be condensed.

  According to a sixth aspect of the present invention, in the solid-state imaging device according to the fourth aspect, the intra-layer lens is a downward convex lens when viewed from the upstream side of the optical path.

  Thereby, the light received appropriately can be condensed.

  According to a seventh aspect of the present invention, in the solid-state imaging device according to the fourth aspect, the intra-layer lens is an upward convex lens and a downward convex lens when viewed from the upstream side of the optical path.

  Thereby, the light received appropriately can be condensed.

  The solid-state imaging device according to any one of claims 1 to 7, wherein the opening has an opening adjacent to the charge transfer region with respect to a center line of the charge transfer region. It is arranged in line symmetry.

  The solid-state imaging device according to any one of claims 1 to 7, wherein the opening has an opening adjacent to the charge transfer region with respect to a center point of the charge transfer region. It is characterized by being arranged point-symmetrically.

  According to a tenth aspect of the present invention, in the solid-state imaging device according to any one of the first to ninth aspects, a color filter layer is provided between the on-chip lens and the photoelectric conversion region.

  In order to achieve the above object, in the method of manufacturing a solid-state imaging device according to claim 11, a plurality of photoelectric conversion regions for converting received light into signal charges are equally spaced two-dimensionally in a row direction and a column direction. A step of arranging and forming; a step of forming a pixel separation region for separating the plurality of photoelectric conversion regions; and a photoelectric conversion region for two rows arranged and read out every two columns of the plurality of photoelectric conversion regions A step of forming a charge transfer region for transferring the signal charges in the column direction, a step of forming a first light-shielding portion on the pixel separation region, and the first light-shielding portion on the charge transfer region. And forming a plurality of openings corresponding to the plurality of photoelectric conversion regions in a row direction by the step of forming a second light-shielding portion having a wider width and the first light-shielding portion and the second light-shielding portion. The process of forming to be unequal intervals , Characterized by comprising a step of forming by arranging in accordance with a plurality of on-chip lens for converging received light and the light to the corresponding photoelectric conversion region, the position of the corresponding opening.

  According to the present invention, the characteristics of each pixel can be made uniform even when the positions of the openings are arranged at unequal intervals.

The figure which shows the light-receiving part of the conventional solid-state image sensor 10. The graph which shows the incident efficiency characteristic of the conventional solid-state image sensor 10 The figure which shows the light-receiving part of the solid-state image sensor 11 of 1st Embodiment. The graph which shows the incident efficiency characteristic of the solid-state image sensor 11 of 1st Embodiment The figure which shows the light-receiving part of solid-state image sensor 11 'of the modification of 1st Embodiment. The figure which shows the light-receiving part of the solid-state image sensor 12 of 2nd Embodiment. The figure which shows the light-receiving part of the solid-state image sensor 13 of 3rd Embodiment. The figure which shows the light-receiving part of the solid-state image sensor 14 of 4th Embodiment. The figure which shows the light-receiving surface of the solid-state image sensor 15 of a honey-comb pixel arrangement | sequence. Enlarged view of the light receiving surface shown in FIG. Top view and cross-sectional view in each manufacturing process of the solid-state imaging device 15

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

[Construction and incident efficiency characteristics of conventional solid-state image sensor]
FIG. 1A is a top view of a light receiving surface of a conventional solid-state imaging device 10, and FIG. 1B is a cross-sectional view taken along a broken line AA ′ in FIG. ) Is an enlarged view of a substantially central portion of the light receiving surface shown in FIG.

  As shown in FIG. 1A, the solid-state imaging device 10 includes a large number of photoelectric conversion elements (photodiodes) 2 formed in an array on the light receiving surface. Each photodiode 2 is equally arranged in the row direction and the column direction, and is separated for each pixel by a pixel separation region (not shown) provided around the photodiode 2. Further, one vertical transfer path (VCCD) 3 is arranged at a ratio of one to two rows of photodiodes 2, and one VCCD 3 is a signal charge of two rows of photodiodes 2 in contact with VCCD 3. Are respectively read and transferred in the vertical direction.

  These photodiode 2 and VCCD 3 are embedded in the semiconductor substrate 1 as shown in FIG. The charge accumulated in the photodiode 2 is read out to the VCCD 3 by charge reading means (not shown).

  Further, on the surface of the semiconductor substrate 1, there are formed a light shielding film S1 that shields the pixel isolation region formed around each photodiode 2, and a light shielding film S2 that shields the VCCD 3, and the width of the light shielding film S2 is as follows. It is larger than the width of the light shielding film S1. The VCCD 3 is not visible from the upper surface (light receiving surface) because it is disposed below the light-shielding film S2, but in FIG. 1A, the VCCD 3 is shown through for convenience.

  Openings O1 and O2 for exposing the photodiodes 2 are formed by the light shielding films S1 and S2. Here, with respect to the VCCD 3, the opening located on the right side in FIG. 1 is O1, and the opening located on the left side is O2. The openings O1 and O2 are arranged at equal intervals in the column direction, but are arranged at unequal intervals in the row direction because the widths of the light shielding films S1 and S2 are different. The openings O1 and O2 are arranged symmetrically with respect to the center line BB ′ of the VCCD 3.

  An insulating film 4, a flat layer 6, and a color filter layer 5 are formed on the upstream side of the light shielding films S1 and S2 in the order closer to the light shielding films S1 and S2. The color filter layer 5 is composed of red (R), green (G), and blue (B) primary color filters arranged in a predetermined arrangement structure such as a Bayer arrangement. Any one color filter is arranged to correspond.

  Furthermore, on-chip lenses L1A and L1B for forming a subject image corresponding to each photodiode 2 are formed on the upstream side of the optical path of the color filter layer 5. Here, with respect to the VCCD 3, the on-chip lens located on the right side in FIG. 1 is L1A, and the on-chip lens located on the left side is L1B, but there is no difference in the structure of the lens itself.

  As shown in FIG. 1C, the on-chip lens L1A (L1B) corresponding to the photodiode 2 positioned substantially at the center of the light receiving surface (effective pixel area) of the solid-state imaging device 11 is directly above (on the upstream side of the optical path). The center L1C when viewed from (1) overlaps with the center 2C when the corresponding photodiode 2 is viewed from directly above. Here, the on-chip lenses L1A and L1B are substantially circular, and the center L1C indicates the center of this circle. The photodiode 2 has a substantially square shape, and the center 2C of the photodiode 2 indicates the intersection of square diagonal lines.

  Further, the on-chip lenses L1A and L1B are directed from the center of the light receiving surface of the solid-state imaging device 11 toward the periphery with reference to the position where the center LC of the on-chip lens and the center 2C of the corresponding photodiode overlap. The photodiodes 2 are arranged with a minute scaling with respect to the arrangement pitch of the photodiodes 2. That is, the on-chip lenses L1A and L1B are gradually shifted from the corresponding photodiode 2 toward the central portion as the distance from the central portion to the peripheral portion of the light receiving surface increases.

  The incident efficiency characteristics of the conventional solid-state imaging device 10 configured as described above will be described.

  In the solid-state imaging device 10, the photodiodes 2 are arranged at equal intervals, but the openings O1 and O2 are not equally spaced in the row direction because the widths of the light shielding films S1 and S2 are different. Therefore, the photodiode 2 is arranged at a position closer to the light shielding film S2 than the distance to the light shielding film S1 in the row direction.

  As a result, as shown in FIG. 1B, when light is incident on the light receiving surface of the solid-state imaging device 10 at an incident angle of θ, the light condensed by the on-chip lens L1A is normally photodiodes. However, the light collected by the on-chip lens L1B may be blocked by the light shielding film S2 on the optical path to the photodiode 2 and may not reach the photodiode 2.

  That is, in the adjacent photodiodes 2, the amount of light to be irradiated is different, so that shading or false color occurs in the image.

  FIG. 2 is a graph showing the result of verifying the relationship (incidence efficiency characteristic) between the incident angle θ of the incident light with respect to the light receiving surface and the amount of light passing through the openings O1 and O2 by an electromagnetic field analysis optical simulation. It is standardized by the incident efficiency. As shown in the figure, it can be seen that the difference in the amount of light passing through the openings O1 and O2 increases as the incident angle θ increases.

  As described above, in the conventional structure of the solid-state imaging device in which the positions of the openings are arranged at unequal intervals, the applicant of the present application has different incident efficiency characteristics of adjacent photoelectric conversion regions depending on the incident angle of incident light. As a result, it has been found that there is a problem that shading and false color occur.

[First Embodiment]
3A is a top view of the light receiving surface of the solid-state imaging device 11 according to the present embodiment, and FIG. 3B is a cross-sectional view taken along a broken line AA ′ in FIG. 3 (c) is an enlarged view of a substantially central portion of the light receiving surface shown in FIG. 3 (a). In addition, the same number is attached | subjected to the part which is common in FIG. 1, and the detailed description is abbreviate | omitted.

  The solid-state image pickup device 11 has the same structure as the solid-state image pickup device 10 including the photodiode 2, the VCCD 3, the light shielding films S 1 and S 2, the insulating film 4, the flat layer 6, and the color filter layer 5 formed on the semiconductor substrate 1. The structure is different, and the arrangement of the on-chip lenses L1A and L1B is different.

  As shown in FIG. 3C, the on-chip lens L1A (L1B) corresponding to the photodiode 2 positioned substantially at the center of the light receiving surface of the solid-state imaging device 11 corresponds to the center L1C when viewed from directly above. It arrange | positions so that it may overlap with the center O1C (O2C) seen from right above the opening O1 (O2) to be performed. Here, the openings O1 and O2 are substantially rectangular, and the centers O1C and O2C indicate the intersections of the diagonal lines of the rectangle of the openings.

  The on-chip lenses L1A and L1B are located from the center of the light receiving surface of the solid-state imaging device 11 with reference to the position where the center L1C of the on-chip lens and the centers O1C and O2C of the corresponding openings O1 and O2 overlap. Toward the periphery, the photodiodes 2 are arranged with a minute scaling with respect to the arrangement pitch of the photodiodes 2. That is, the on-chip lenses L1A and L1B are arranged so as to be gradually shifted from the corresponding openings O1 and O2 toward the center as the distance from the center to the periphery of the light receiving surface increases.

  By arranging the on-chip lens in this way, as shown in FIG. 3B, the focal position of the on-chip lens L1A and the focal position of the on-chip lens L1B are the same positions in the planes of the openings O1 and O2. It becomes. Therefore, the light condensed by the on-chip lens L1A and the light condensed by the on-chip lens L1B are equally incident on the respective photodiodes 2.

  FIG. 4 is a graph showing the result of verifying the incident efficiency characteristic of the solid-state imaging device 11 of the present embodiment by electromagnetic field analysis optical simulation, as in the case of FIG. As shown in the figure, it can be seen that there is no difference in the amount of light passing through the openings O1 and O2, irrespective of the incident angle θ, and they are substantially the same.

  As described above, by arranging the on-chip lens with the position of the opening as a reference, it is possible to suppress the problem of shading and false color even if the opening is a solid-state imaging device having unequal intervals. Also, conventional on-chip lens scaling can be applied.

  Note that the present invention can also be applied to a non-scaled solid-state imaging device. In this case, the center position of all the on-chip lenses may be arranged so as to coincide with the center position of the opening.

[Modification of First Embodiment]
In the solid-state imaging device 11 of the first embodiment, the position of the opening is set so that the focal position of the on-chip lens L1A and the focal position of the on-chip lens L1B are the same in the plane of the openings O1 and O2. Although the on-chip lens is arranged as a reference, this may be realized by changing the shape of the on-chip lens.

  FIG. 5 is a diagram illustrating a light receiving unit of a solid-state imaging device 11 ′ according to a modification of the first embodiment. In addition, the same number is attached | subjected to the part which is common in FIG. 1, and the detailed description is abbreviate | omitted.

  As shown in the figure, the on-chip lenses L1A ′ and L1B ′ have an asymmetric shape, and are configured such that the focal positions thereof are the same in the planes of the openings O1 and O2. Yes. Therefore, the light condensed by the on-chip lens L1A ′ and the light condensed by the on-chip lens L1B ′ are equally incident on the respective photodiodes 2.

[Second Embodiment]
FIG. 6 is a cross-sectional view of the solid-state imaging device 12 according to the present embodiment. In addition, the same number is attached | subjected to the part which is common in FIG. 1, and the detailed description is abbreviate | omitted.

  In the solid-state imaging device 12, a lens layer 21 is formed between the insulating film 4 and the flat layer 6. The lens layer 21 is formed flat on the insulating film 4 side, and on the flat layer 6 side, the upper convex lenses L2A and L2B having an upward convex shape projecting toward the light receiving surface correspond to the respective photodiodes 2. Are formed one by one.

  The in-layer upper convex lenses L2A and L2B are lenses for increasing the light collection efficiency, and the incident light is condensed together with the corresponding on-chip lenses L1A and L1B and is incident on the corresponding photodiode 2.

  As in the first embodiment, the on-chip lenses L1A and L1B are located directly above the opening O1 (O2) corresponding to the center L1C when viewed from directly above in the center of the light receiving surface of the solid-state imaging device 12. Is positioned so as to overlap with the center O1C (O2C) viewed from above, and further, with respect to the arrangement pitch of the photodiodes 2 from the center to the periphery of the light receiving surface, the position overlapping with the center of the corresponding opening Are arranged with a small scaling with reference to.

  On the other hand, all the in-layer upward convex lenses L2A and L2B are arranged so that the center L2C when viewed from directly above overlaps the center O1C (O2C) when the corresponding opening O1 (O2) is viewed from directly above. Has been. That is, no scaling is performed.

  With this configuration, the focal point of the lens system including the on-chip lenses L1A and L1B and the in-layer upper convex lenses L2A and L2B is at the same position in the surfaces of the openings O1 and O2. Therefore, even if the openings are unequal, the problem of shading and false color can be suppressed.

[Third Embodiment]
FIG. 7 is a cross-sectional view of the solid-state imaging device 13 according to the present embodiment. In addition, the same number is attached | subjected to the part which is common in FIG. 1, and the detailed description is abbreviate | omitted.

  As in the second embodiment, the lens layer 21 is formed between the insulating film 4 and the flat layer 6. However, the lens layer 21 of the present embodiment is formed flat on the flat layer 6 side. On the insulating film 4 side, in-layer lower convex lenses L3A and L3B having a downward convex shape projecting toward the photodiode 2 are formed one by one corresponding to each photodiode 2.

  The in-layer lower convex lenses L3A and L3B are lenses for increasing the light collection efficiency, and collect the incident light together with the corresponding on-chip lenses L1A and L1B and make the incident light incident on the corresponding photodiode 2.

  As before, the on-chip lenses L1A and L1B are viewed from directly above the opening O1 (O2) corresponding to the center L1C when viewed from directly above the center of the light receiving surface of the solid-state imaging device 13. It is arranged so as to overlap with the center O1C (O2C), and further, with respect to the arrangement pitch of the photodiodes 2 from the central part to the peripheral part of the light receiving surface, the position overlapping the center of the corresponding opening as a reference Arranged with minute scaling.

  On the other hand, all the in-layer lower convex lenses L3A and L3B are arranged such that the center L3C when viewed from directly above overlaps the center O1C (O2C) when the corresponding opening O1 (O2) is viewed from directly above. Has been.

  With this configuration, the focal point of the lens system including the on-chip lenses L1A and L1B and the in-layer lower convex lenses L3A and L3B is at the same position in the openings O1 and O2. Therefore, even if the openings are unequal, the problem of shading and false color can be suppressed.

[Fourth Embodiment]
FIG. 8 is a cross-sectional view of the solid-state imaging device 14 according to the present embodiment. In addition, the same number is attached | subjected to the part which is common in FIG. 6, FIG. 7, and the detailed description is abbreviate | omitted.

  In the lens layer 21 of the present embodiment, in-layer upper convex lenses L2A and L2B having an upward convex shape projecting toward the light receiving surface on the flat layer 6 side, and projecting toward the photodiode 2 on the insulating film 4 side. One in-layer lower convex lens L3A, L3B having a downward convex shape is formed corresponding to each photodiode 2 one by one.

  The in-layer upper convex lenses L2A, L2B and the in-layer lower convex lenses L3A, L3B condense incident light together with the corresponding on-chip lenses L1A, L1B, enter the corresponding photodiode 2, and increase the condensing efficiency.

  The on-chip lenses L1A and L1B are directed from the center of the light-receiving surface toward the periphery with reference to the position where the center LC of the on-chip lens and the center O1C (O2C) of the corresponding opening O1 (O2) overlap. The photodiodes 2 are scaled with respect to the arrangement pitch of the photodiodes 2.

  Similarly to the second and third embodiments, all the in-layer upper convex lenses L2A and L2B and all the in-layer lower convex lenses L3A and L3B have the center L2C when viewed from directly above. , L3C is arranged so as to overlap with the center O1C (O2C) when the corresponding opening O1 (O2) is viewed from directly above.

  With this configuration, the focal point of the lens system including the on-chip lenses L1A and L1B, the in-layer upper convex lenses L2A and L2B, and the in-layer lower convex lenses L3A and L3B is the same position in the openings O1 and O2. Become. Therefore, even if the openings are unequal, the problem of shading and false color can be suppressed.

  In the first to fourth embodiments, the solid-state imaging device 11 having a so-called Bayer arrangement has been described as an example, but the present invention can also be applied to solid-state imaging devices having other arrangements.

  For example, as shown in FIG. 9, a so-called honeycomb pixel array in which the even-numbered photodiodes 2 are shifted by 1/2 pitch with respect to the odd-numbered photodiodes 2 (in FIG. 9A, tilted by 45 degrees). It can also be applied to the solid-state imaging device 15 shown in FIG.

  The photodiodes 2 of the solid-state image sensor 15 are arranged at equal intervals in the row direction and the column direction.

  As shown in FIG. 9A, the VCCD 3 of the solid-state imaging device 15 has a lightning bolt type so as to transfer charges through the upper and right sides of each photodiode 2 or the lower and left sides of each photodiode 2. Has been placed. Further, if it is considered that the photodiodes 2 form an oblique 45-degree column, the VCCD 3 is arranged at a ratio of one to the two rows of photodiodes 2. The VCCD 3 transfers the signal charges of the photodiodes 2 for two columns in contact with the VCCD 3.

  The light shielding film S2 that shields the VCCD 3 is formed to have a width larger than the light shielding film S1 that shields the pixel separation region formed around each photodiode 2, and as shown in FIG. O2 is arranged as a point object with respect to the center point 3C of the VCCD 3 forming one straight line portion. The opening located on the right side of the VCCD 3 is O1, and the opening located on the left is O2.

  Further, as in the past, the center L1C of the on-chip lens L1A and the center O1C of the opening O1 are arranged so as to overlap each other, and the center L1C of the on-chip lens L1B is arranged so as to overlap the center O2C of the opening O2. .

  Therefore, as shown in FIG. 9B, the focal position of the on-chip lens L1A and the focal position of the on-chip lens L1B are the same position in the surfaces of the openings O1 and O2. That is, the light condensed by the on-chip lens L1A and the light condensed by the on-chip lens L1B are equally incident on the respective photodiodes 2.

  Thus, also in the honeycomb pixel array, the problem of shading and false color can be suppressed by overlapping the center of the on-chip lens and the center of the opening. Even in the case where an intralayer lens is provided, the intralayer lens may be arranged in the same manner as in the second to fourth embodiments.

[Manufacturing method of individual imaging device]
Finally, the manufacturing flow of the solid-state imaging device according to the present invention will be described. Here, the individual imaging device 15 shown in FIG. 9 will be described as an example.

  The manufacture of the individual image pickup device 15 can be realized by the same manufacturing flow as that of the conventional individual image pickup device, and the difference from the conventional individual image pickup device can be dealt with only by changing the photomask.

  FIGS. 11 (i) to (iii) are diagrams showing (a) a layout viewed from the upper surface and (b) a cross section taken along a broken line AA ′ in each manufacturing process of the solid-state imaging device 15.

  FIG. 11I is a diagram showing a layout and a cross section when the VCCD 3 is formed. The broken lines in the figure indicate pixel boundaries, and the arrows in the figure indicate the charge transfer direction in the VCCD 3.

  As shown in FIGS. 11 (i) and 11 (b), first, a photodiode 2 and a VCCD 3 are formed in a semiconductor substrate 1. As shown in FIGS. 11 (i) and 11 (a), the photodiodes 2 are two-dimensionally arranged at equal intervals and are separated by pixel separation regions (substrate regions). The VCCD 3 is arranged at a ratio of one to the two rows of photodiodes 2. That is, the VCCD 3 is thinned out one by one as compared with the solid-state image pickup device arranged at a ratio of one to the photodiodes 2 in one row.

  FIG. 11 (ii) is a diagram showing a layout and a cross section when the light shielding films S1 and S2 are formed. For convenience, the VCCD 3 is shown through.

  A transfer electrode 31 is formed on the VCCD 3. The transfer electrode 31 is an electrode for outputting the signal charge on the VCCD 3 read from the photodiode 2 line by line to a vertical transfer path (not shown) in synchronization with the supplied clock. Similarly, transfer electrodes 31 are formed in the pixel isolation region where the VCCD 3 is not formed, and a silicon oxide film 32 is formed on the transfer electrodes 31.

  Further, a light shielding film S1 that shields the pixel separation region and a light shielding film S2 that shields the VCCD 3 are formed. The light shielding film S1 that shields light from the pixel separation region does not have the VCCD 3 below it, and even if light shielding is incomplete, smear does not occur, so that the side wall of the light shielding film can be made thin. Therefore, the width of the light shielding film S1 is smaller than the width of the light shielding film S2. The light shielding film S1 may have a structure without a side wall.

  Thus, since the widths of the light shielding films S1 and S2 are different, the openings O1 and O2 formed from the light shielding films S1 and S2 are formed at unequal intervals.

  FIG. 11 (iii) is a diagram showing a layout and a cross section when the on-chip lenses L1 and L2 are formed. An insulating film 4 including a flat layer 6 and a color filter layer 5 are formed on the light shielding films S1 and S2.

  Further, a resist is patterned on the color filter layer 5, and on-chip lenses L1 and L2 are formed by reflowing the resist. As described above, the on-chip lenses L1 and L2 are lenses for condensing incident light on the corresponding photodiodes 2 respectively.

  Here, the positions where the on-chip lenses L1 and L2 are arranged are different from those of the conventional individual imaging element. That is, the conventional individual imaging device is arranged so that the center L1C (L2C) when viewed from directly above (upstream side of the optical path) overlaps the center 2C when the corresponding photodiode 2 is viewed from directly above. The individual imaging element 15 is arranged so that the center L1C when viewed from directly above overlaps the center O1C (O2C) viewed from directly above the corresponding opening O1 (O2).

  Therefore, the arrangement of the on-chip lenses L1 and L2 is changed by changing the photomask for patterning the resist of the on-chip lenses L1 and L2.

  As described above, the arrangement of the on-chip lenses can be changed by simply changing the photomask with respect to the conventional individual imaging element. Therefore, there is an advantage that it can be realized by a conventional manufacturing method and has excellent manufacturing stability.

  In addition, although the manufacturing method of the individual image pick-up element 15 was demonstrated here, also in the solid-state image sensors 11-14, the arrangement | positioning of an on-chip lens is changed only by changing a photomask with respect to the conventional individual image sensor. It is possible to obtain the effects of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor substrate, 2 ... Photodiode, 2C ... Center of photoelectric conversion area, 3 ... Vertical transfer path (VCCD), 5 ... Color filter layer 10, 11, 11 ', 12, 13, 14, 15 ... Solid-state imaging Element, 21 ... lens layer, 31 ... transfer electrode, 32 ... oxide film, L1A, L1B ... on-chip lens, L1C ... center of on-chip lens, L2A, L2B ... upper convex lens in layer, L2C ... upper convex lens in layer , L3A, L3B ... lower convex lens in layer, L3C ... center of lower convex lens in layer, O1 ... opening, O1C ... center of opening O1, O2 ... opening, O2C ... center of opening O2, S1, S2 ... light shielding film

Claims (11)

A photoelectric conversion region that converts received light into a signal charge, arranged in two-dimensional equal intervals in the row direction and the column direction, and a plurality of photoelectric conversion regions each separated by a pixel separation region;
A charge transfer region arranged for every two columns of the plurality of photoelectric conversion regions, and for transferring the signal charges of the read photoelectric conversion regions for two columns in the column direction;
A first light shielding portion formed on the pixel isolation region;
A second light shielding part formed on the charge transfer region, the second light shielding part being wider than the first light shielding part;
A plurality of openings formed by the first light-shielding part and the second light-shielding part, wherein a plurality of openings corresponding to the plurality of photoelectric conversion regions are formed with unequal intervals in the row direction. And
A plurality of on-chip lenses for condensing received light on the corresponding photoelectric conversion regions, and a plurality of on-chip lenses arranged according to the positions of the corresponding openings,
A solid-state imaging device comprising:   In the photoelectric conversion region located at substantially the center of the two-dimensionally arranged photoelectric conversion regions, the on-chip lens corresponding to the photoelectric conversion region corresponds to the center of the on-chip lens and the photoelectric conversion region. The solid-state imaging device according to claim 1, wherein the solid-state imaging device is disposed so as to coincide with a center of the opening.   The plurality of on-chip lenses have an on-chip corresponding to the photoelectric conversion region located at the substantially central portion with reference to a position where the center of each on-chip lens coincides with the center of the opening corresponding to the on-chip lens. The solid-state image pickup device according to claim 2, wherein the solid-state image pickup device is scaled according to a distance from the lens. Between each on-chip lens and each corresponding photoelectric conversion region, an in-layer lens for condensing received light to the corresponding photoelectric conversion region together with the on-chip lens,
4. The solid-state imaging device according to claim 1, wherein the inner lens is disposed so that a center thereof coincides with a center of a corresponding opening. 5.   The solid-state imaging device according to claim 4, wherein the intra-layer lens is an upward convex lens when viewed from the upstream side of the optical path.   The solid-state imaging device according to claim 4, wherein the inner lens is a downward convex lens when viewed from the upstream side of the optical path.   The solid-state imaging device according to claim 4, wherein the in-layer lens is an upward convex lens and a downward convex lens as viewed from the upstream side of the optical path.   8. The opening according to claim 1, wherein the opening adjacent to the opening via the charge transfer region is arranged symmetrically with respect to the center line of the charge transfer region. 9. Solid-state image sensor.   8. The opening according to claim 1, wherein the opening adjacent to the opening via the charge transfer region is arranged point-symmetrically with respect to the center point of the charge transfer region. 9. Solid-state image sensor.   The solid-state imaging device according to claim 1, further comprising a color filter layer between the on-chip lens and the photoelectric conversion region. A step of forming a plurality of photoelectric conversion regions for converting received light into signal charges by arranging them at two-dimensional intervals in the row direction and the column direction; and
Forming a pixel separation region that separates each of the plurality of photoelectric conversion regions;
A step of forming a charge transfer region arranged for every two columns of the plurality of photoelectric conversion regions and transferring the signal charges of the read photoelectric conversion regions for two columns in the column direction;
Forming a first light-shielding portion on the pixel isolation region;
Forming a second light shielding part having a width wider than the first light shielding part on the charge transfer region;
Forming a plurality of openings corresponding to the plurality of photoelectric conversion regions by the first light-shielding portion and the second light-shielding portion so that intervals in a row direction are unequal intervals;
A step of arranging and forming a plurality of on-chip lenses for condensing received light on the corresponding photoelectric conversion regions, respectively, according to the positions of the corresponding openings, and
A method for manufacturing a solid-state imaging device.