JP2012099620A - Semiconductor device, solid state imaging device, and method for manufacturing the same and electronic information apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid state imaging device having a high converging rate at a low cost as a solid state imaging device such as a CCD image sensor.SOLUTION: A solid state imaging device 1a formed in a semiconductor substrate 10 and having a photo-electric conversion part 11 for photo-electric converting an incident light comprises a collecting lens 24 arranged on the semiconductor substrate so as to face the photo-electric conversion part and collecting the incident light; and an optical waveguide 22a arranged between the photo-electric conversion part and the collecting lens and guiding the incident light collected by the collecting lens to the photo-electric conversion part. The collecting lens and the optical waveguide are positioned according to a cross sectional shape of a part contacting with both of them so that their center axes may be aligned with each other.

Description

  The present invention relates to a semiconductor device, a solid-state imaging device, a manufacturing method thereof, and an electronic information device, and more particularly, a CCD (Charge Coupled Device) image sensor configured by a semiconductor device that captures an image by photoelectrically converting image light from a subject. The present invention relates to a solid-state imaging device and a method for manufacturing the same, and an electronic information device equipped with the solid-state imaging device. Such an electronic information device is, for example, a digital image using a solid-state imaging device as an image input device in an imaging unit. They are digital cameras such as video cameras and digital still cameras, image input cameras such as surveillance cameras, scanner devices, facsimile devices, television telephone devices, and mobile phone devices with cameras.

  Conventional solid-state image sensors using semiconductor elements such as CCD image sensors are used in various applications such as digital cameras, scanner devices, digital copying machines, and facsimile machines. Further, along with the widespread use, not only requests for downsizing and cost reduction, but also higher functions and higher performance, such as an increase in the number of pixels and an improvement in light receiving sensitivity, are increasing.

  FIG. 11 is a schematic diagram of the surface of a CCD image sensor which is an example of a solid-state imaging device.

  In the solid-state imaging device 100, a large number of photodiodes (PD) 111 are arrayed on the surface of a semiconductor substrate 110, and in the illustrated example, are arranged in a square lattice shape. In addition, a vertical transfer unit (VCCD) 140 that receives and transfers signal charges accumulated according to the amount of light received by the photodiode 111 is provided on the side of each photodiode row, and a vertical transfer unit is provided on the lower side of the semiconductor substrate 110. A horizontal transfer unit (HCCD) 150 that transfers the signal charge received from 140 to the output stage is provided, and an amplifier 160 that outputs a voltage value signal corresponding to the signal charge amount is provided at the output stage of the horizontal transfer unit 150. Yes. A light shielding film, a color filter layer, and a microlens layer (not shown) are provided on the surface of the photodiode 111.

  In such a solid-state imaging device 100, a technique of providing an on-chip microlens on a color filter or forming an in-layer lens immediately above a pixel is used to improve sensitivity, in Patent Document 1, In order to improve the light collection efficiency, an optical waveguide integrated with a condensing lens has been proposed.

  12 is a diagram showing the structure of the cross section along the line XX ′ of FIG. 11, and FIG. 12A shows the case where the optical axis of the optical waveguide and the optical axis of the lens coincide with each other. (B) has shown the case where the optical axis of an optical waveguide and the optical axis of a lens have shifted | deviated.

  As shown in FIG. 12A, the solid-state imaging device 100 includes an optical waveguide 122a provided above the photoelectric conversion unit 111, an interlayer insulating film 120 that covers the side of the optical waveguide, and the interlayer insulating film. A transfer electrode (gate electrode) 116 and a light-shielding film 117 which are provided inside and insulated from each other by the interlayer insulating film, and a condensing lens 124 provided on the optical waveguide 122a, and the optical waveguide 122a and The refractive index of the condenser lens 124 is higher than that of the interlayer insulating film 120, and the optical waveguide 122 a has a tapered shape that spreads in the direction from the photoelectric conversion unit 111 toward the condenser lens 124. The condenser lens 124 is made of the same material as the optical waveguide 122a and is integrated with the optical waveguide 122a.

  Next, a manufacturing method will be described.

  FIG. 13 is a diagram for explaining a conventional method for manufacturing a solid-state imaging device, and FIGS. 13A to 13F show cross-sectional structures in main steps in the manufacturing method.

  First, processing until the cross-sectional structure shown in FIG.

  A photoelectric conversion unit 111, a channel stop 112, a charge transfer channel 113, and a read gate unit 114 are formed on the surface of a semiconductor substrate 110 made of silicon by ion implantation. Subsequently, an insulating film 115 which is a silicon oxide film having a thickness of 100 to 3000 nm is formed on the surface of the semiconductor substrate 110 by silicon thermal oxidation or a CVD method. Next, for example, a polysilicon film is deposited to a thickness of about 50 to 300 nm by a CVD method. Further, an n-type impurity such as phosphorus is introduced by thermal diffusion or ion implantation. Thereafter, the transfer electrode 116 is formed by anisotropic etching using a photoresist patterned in a predetermined pattern by a photolithography technique as a mask.

  Next, a first interlayer insulating film 117 is formed by polysilicon film deposition or an oxide film deposition by a CVD method. Next, for example, a silicon nitride film is deposited as an antireflection film, and an antireflection film 118 is formed by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask. Next, a light shielding film material such as tungsten is deposited, and a light shielding film 119 is formed by photolithography. Next, a second interlayer insulating film 120 that is a silicon oxide film is formed by a CVD method.

  Subsequently, processing for obtaining the cross-sectional structures shown in FIGS. 13B to 13F will be sequentially described.

  Next, after the cross-sectional structure shown in FIG. 13A is obtained, as shown in FIG. 13B, the second interlayer is formed using the photoresist 121 patterned in a predetermined pattern by a photolithography technique as a mask. The insulating film 120 is anisotropically etched to form a region to be an optical waveguide.

  Next, as shown in FIG. 13C, an optical waveguide material 122 which is a silicon nitride film having a thickness of 100 to 1000 nm is formed by a CVD method.

  Next, as shown in FIG. 13D, the optical waveguide material 122 is processed so as to have a flat upper surface by a resist etch back method or a CMP method.

  Thereafter, as shown in FIG. 13E, a resist film 123 having the same shape as that of the condensing lens 124 (see FIG. 13F) is formed in a region located above the photoelectric conversion element 111 on the optical waveguide material 122. Are formed by patterning and reflowing the resist material layer.

  Thereafter, in the step shown in FIG. 13F, etching back is performed again using the resist film 123 as a mask to remove the exposed portion of the optical waveguide material 122, whereby a resist is formed on the upper surface of the optical waveguide material 122. The optical waveguide 112 a integrated with the condensing lens 124 is formed by transferring the shape.

  In order to improve the light collection efficiency, there is a solid-state imaging device in which an optical waveguide is disposed below the condenser lens, as disclosed in Patent Document 2 in addition to Patent Document 1 described above.

JP 2006-49825 A JP 2007-201091 A

  However, in Patent Document 1 and Patent Document 2, since the condenser lens is formed by patterning using a lithography technique, the condenser lens cannot be formed with high accuracy with respect to the optical waveguide, and FIG. When the optical axis of the condensing lens 124 is deviated from the optical axis of the optical waveguide 122a as in the solid-state imaging device 100a shown in FIG.

  The present invention has been made in view of the above-described conventional problems, and is a condenser lens integrated type that can match the optical axis of the condenser lens with the optical axis of the optical waveguide with low cost and high controllability. It is an object of the present invention to obtain a semiconductor device, a solid-state imaging device and a manufacturing method thereof having an optical waveguide, and an electronic information device equipped with such a solid-state imaging device.

  A semiconductor device according to the present invention is a semiconductor device that is formed in a semiconductor substrate and has a photoelectric conversion unit that photoelectrically converts incident light, and is disposed on the semiconductor substrate so as to face the photoelectric conversion unit. A condensing lens that condenses light, and an optical waveguide that is disposed between the photoelectric conversion unit and the condensing lens and guides incident light collected by the condensing lens to the photoelectric conversion unit. The condensing lens and the optical waveguide are positioned by a cross-sectional shape of a portion where they contact each other so that the respective central axes are in a predetermined positional relationship, thereby achieving the above object. The

  According to the present invention, in the semiconductor device, an upper surface of the optical waveguide that is in contact with the condenser lens has a convex cross-sectional shape, and a sectional shape of the lower surface of the condenser lens that is in contact with the optical waveguide is the optical waveguide. Preferably, the waveguide has a concave cross-sectional shape that engages with the convex cross-sectional shape of the upper surface of the waveguide, and the optical waveguide and the condensing lens are integrally formed.

  According to the present invention, in the semiconductor device, the refractive index of the optical waveguide and the condensing lens is such that light incident on the optical waveguide from the condensing lens is a cross section of a contact surface between the optical waveguide and the condensing lens. It is preferable that the refractive index is set so as to be refracted away from the optical axis of the optical waveguide according to the shape.

  According to the present invention, in the semiconductor device, the refractive index of the optical waveguide is preferably equal to the refractive index of the condenser lens.

  According to the present invention, in the semiconductor device described above, the cross-sectional shape of the contact surface between the optical waveguide and the condenser lens is a substantially isosceles triangle whose apex is located on the optical axis of the optical waveguide and is axisymmetric with respect to the optical axis. Preferably, the hypotenuses located on both sides of the optical axis are curved downward, and the refractive index of the optical waveguide is preferably smaller than the refractive index of the condenser lens.

  A solid-state imaging device according to the present invention is a solid-state imaging device having a pixel array formed by arranging a plurality of pixels in a matrix, and photoelectrically converting incident light at each pixel to output an image signal of a subject. A photoelectric conversion unit that is formed for each pixel on the semiconductor substrate and photoelectrically converts incident light, and a collection unit that is disposed for each pixel on the semiconductor substrate to face the photoelectric conversion unit and collects the incident light. An optical lens, and an optical waveguide that is arranged for each pixel so as to be positioned between the photoelectric conversion unit and the condenser lens, and guides incident light collected by the condenser lens to the photoelectric conversion unit. The condensing lens and the optical waveguide are positioned by a cross-sectional shape of a portion where they are in contact with each other so that their optical axes coincide with each other, thereby achieving the above object.

  In the solid-state imaging device according to the aspect of the invention, it is preferable that the refractive index of the condenser lens is the same as or higher than the refractive index of the optical waveguide.

  According to the present invention, in the solid-state imaging device, an interlayer insulating film is formed on the semiconductor substrate so as to cover a side surface of the optical waveguide, and the optical waveguide and the condenser lens are refracted by the interlayer insulating film. The refractive index is preferably higher than the refractive index.

  According to the present invention, in the solid-state imaging device, an upper surface of the optical waveguide that is in contact with the condenser lens has a convex cross-sectional shape, and a lower surface of the condenser lens that is in contact with the optical waveguide is the surface of the optical waveguide. It is preferable to have a concave cross-sectional shape that engages with the convex cross-sectional shape of the upper surface, and the optical waveguide and the condenser lens are integrally formed.

  In the solid-state imaging device according to the aspect of the invention, it is preferable that the condenser lens is disposed immediately above the optical waveguide so that a vertex thereof is located on a central axis of the optical waveguide.

  In the solid-state imaging device according to the aspect of the invention, it is preferable that the condenser lens is arranged so as to be shifted from a position directly above the optical waveguide so that a vertex thereof is located at a position deviating from a central axis of the optical waveguide. .

  According to the present invention, in the solid-state imaging device, in a region other than a peripheral portion of the pixel array, the condenser lens is disposed immediately above the optical waveguide so that a vertex thereof is located on a central axis of the optical waveguide. In the peripheral portion of the pixel array, the condensing lens has an oblique angle in which the apex of the condensing lens and the center of the photoelectric conversion unit are obliquely incident on the pixels of the pixel array from the outside of the pixel array. It is preferable that the apex of the optical waveguide be disposed so as to be located along the optical axis of the incident light.

  In the solid-state imaging device, the present invention has a charge transfer unit that transfers a signal charge obtained by photoelectric conversion of incident light in each pixel, and a gate electrode that constitutes the charge transfer unit on the semiconductor substrate The conductive layer constituting the gate electrode has a planar shape surrounding the photoelectric conversion portion of each pixel and has a certain thickness, and the optical waveguide and the light condensing in each pixel. It is preferable that the lens is positioned in a self-aligned manner by the planar shape of the conductor layer constituting the gate electrode.

  According to the present invention, in the solid-state imaging device, on the conductor layer constituting the gate electrode, the positions of the optical waveguide and the condenser lens that are positioned in a self-aligned manner by the planar shape of the conductor layer are adjusted. The sacrificial layer is preferably formed by photolithography.

  In the solid-state imaging device according to the aspect of the invention, it is preferable that the gate electrode is a transfer gate electrode constituting a vertical charge transfer unit that transfers the signal charge in a vertical direction.

  The solid-state imaging device manufacturing method according to the present invention includes a condenser lens corresponding to each pixel, and an optical waveguide that guides light from the condenser lens to a photoelectric conversion unit of the corresponding pixel, and the condenser lens Is a method of manufacturing a solid-state imaging device in which an optical waveguide and a light guide are positioned in a self-aligned manner, wherein a photoelectric conversion unit constituting the pixel and a signal charge generated by the photoelectric conversion unit are transferred in a semiconductor substrate Forming a transfer gate electrode for forming an optical waveguide material layer on the entire surface through the insulating film so that a step on the surface of the semiconductor substrate is reflected, and forming the optical waveguide material on the optical waveguide material layer A step of laminating a sacrificial layer having an etching rate lower than that of the layer; a step of simultaneously etching the optical waveguide material layer and the sacrificial film to form an optical waveguide having a cross-sectional shape determined by a step on the surface of the semiconductor substrate; Collected above the optical waveguide The lens, the cross-sectional shape of the optical waveguide is intended and a step of forming self-aligned manner positioning said thereby achieving the objective.

    The present invention includes a step of forming the insulating film using a photolithography process in the method for manufacturing a solid-state imaging device, wherein the insulating film forming step includes a step of forming an insulating material layer on the entire surface of the semiconductor substrate. And forming the insulating film by patterning the insulating material layer so as to cover the gate electrode.

  The present invention includes the step of forming a sacrificial layer on the gate electrode by using a photolithography process in the method for manufacturing a solid-state imaging device, wherein the step of forming the insulating film includes an insulating material layer as the photoelectric conversion unit. It is preferable to include a step of forming along the surfaces of the gate electrode and the sacrificial layer.

  The present invention provides the method for manufacturing a solid-state imaging device, wherein the sacrificial layer is patterned so that a center axis of the optical waveguide is shifted from a center position between the gate electrodes located on both sides of the photoelectric conversion unit. Preferably it is.

  An electronic information device according to the present invention is an electronic information device including an imaging unit that captures an image of a subject, and the imaging unit is the above-described solid-state imaging device according to the present invention, thereby achieving the above object. Is done.

  Next, the operation will be described.

  In the present invention, the condensing lens and the optical waveguide are positioned by the cross-sectional shape of the contact portion so that the central axes thereof coincide with each other, so that the position of the condensing lens is not affected by photoalignment deviation. Is automatically determined with respect to the optical waveguide, and an optical waveguide integrated with a condensing lens in which the optical axis is not shifted can be obtained, and a semiconductor device such as a solid-state imaging device having a stable condensing rate can be realized. .

  Further, in the present invention, the position of the optical waveguide is determined in a self-aligned manner with respect to the gate electrode by the step formed by the gate electrode arranged so as to surround the photoelectric conversion unit, and the position of the condensing lens with respect to the optical waveguide is further determined. In addition to being able to determine in a self-aligned manner, the position of the sacrificial film (dummy insulating film) formed on the gate electrode by using photolithography technology is adjusted with respect to the gate electrode, so that the center of the photoelectric conversion unit The center position of the optical waveguide and the condenser lens with respect to the position can be adjusted.

  In addition, such an optical waveguide integrated with a condensing lens is a self-aligned central axis (optical axis) of the condensing lens and the optical waveguide due to a step structure on the surface of the semiconductor substrate for positioning the optical waveguide on the semiconductor substrate. (Axis) can be formed by a simple manufacturing method, and thus the cost can be reduced.

  Also, in the present invention, the sacrificial film is arranged so as to be shifted with respect to the photoelectric conversion unit, so that the center of the optical waveguide can be shifted with respect to the condensing lens, and the structure with high light collection efficiency for oblique light Is obtained.

  In the present invention, the condensing lens is disposed immediately above the optical waveguide so that the apex of the condensing lens is located on the central axis of the optical waveguide in a region other than the peripheral portion of the pixel array, and the pixel In the peripheral part of the array, the optical axis of oblique incident light in which the apex of the condensing lens and the center of the photoelectric conversion unit are obliquely incident on the pixels of the pixel array from the outside of the pixel array Optimum positional relationship between the optical waveguide and the condensing lens according to the position of each pixel in the pixel array by disposing the vertex of the condensing lens away from the central axis of the optical waveguide And the light collection rate in the solid-state imaging device can be maximized.

  As described above, according to the present invention, the position of the condensing lens is automatically determined with respect to the optical waveguide without being affected by the photo-alignment, and thus the condensing lens-integrated light guide that does not further shift the optical axis. A waveguide can be obtained, and a stable light collection rate in a semiconductor device such as a solid-state imaging device can be realized.

  In addition, such an optical waveguide integrated with a condensing lens is a self-aligned central axis (optical axis) of the condensing lens and the optical waveguide due to a step structure on the surface of the semiconductor substrate for positioning the optical waveguide on the semiconductor substrate. The manufacturing cost of a semiconductor device such as a solid-state imaging device can be reduced.

FIG. 1 is a diagram for explaining the structure of a solid-state imaging device according to an embodiment of the present invention. FIG. 1A is a plan view showing the structure of a portion corresponding to one pixel, and FIG. FIG. 1C is a cross-sectional view showing the structure of the cross section taken along the line AA ′ of FIG. 1, and FIG. 1C is a cross-sectional view showing the structure of the cross section taken along the line BB ′ of FIG. FIG. 2 is a diagram for explaining a method for manufacturing a solid-state imaging device according to Embodiment 1 of the present invention, and FIGS. 2A to 2G show cross-sectional structures in main steps in this manufacturing method. Yes. FIG. 3 is a diagram for explaining the structure of a solid-state imaging device according to Embodiment 2 of the present invention. FIG. 3A is a plan view showing the structure of a portion corresponding to one pixel in the solid-state imaging device. (B) is sectional drawing which shows the structure of the CC 'line cross section of FIG. 3, FIG.3 (c) is sectional drawing which shows the structure of the DD' line cross section of FIG. 4A and 4B are diagrams for explaining a method of manufacturing a solid-state imaging device according to Embodiment 2 of the present invention. FIGS. 4A to 4G show cross-sectional structures in main steps of the manufacturing method. Yes. FIG. 5 is a diagram for explaining the structure of the solid-state imaging device according to the third embodiment of the present invention, and shows a cross-sectional structure of a portion corresponding to the cross section taken along line C-C ′ of FIG. 6A and 6B are diagrams for explaining a method for manufacturing a solid-state imaging device according to Embodiment 3 of the present invention. FIGS. 6A to 6G show cross-sectional structures in main steps in the manufacturing method. Yes. FIG. 7 is a diagram for explaining the structure of a solid-state imaging device according to Embodiment 4 of the present invention, and is a schematic diagram schematically showing the overall configuration. FIG. 8 is a diagram illustrating a cross-sectional structure of the solid-state imaging device according to the fourth embodiment of the present invention illustrated in FIG. 7 at a predetermined portion, and FIGS. 8A, 8B, and 8C are respectively illustrated. 7 shows the structure of the Lx-Lx ′ cross section, the Mx-Mx ′ cross section, and the Rx-Rx ′ cross section of FIG. 7, and FIGS. 8D, 8E, and 8F show the Ly-Ly ′ cross section, The structure of a My-My 'cross section and a Ry-Ry' cross section is shown. FIG. 9 is a diagram showing a cross-sectional structure of the solid-state imaging device according to the fourth embodiment of the present invention shown in FIG. 7 at a predetermined portion, and FIGS. 9A, 9B, and 9C are respectively shown. 7 shows the structure of the Uy-Uy ′ cross section, My-My ′ cross section, and By-By ′ cross section of FIG. 7, and FIGS. 9D, 9E, and 9F show the Ux-Ux ′ cross section, The structure of the Mx-Mx ′ section and the Bx-Bx ′ section is shown. FIG. 10 is a block diagram illustrating a schematic configuration example of an electronic information device using the solid-state imaging device according to any of Embodiments 1 to 4 as an imaging unit as Embodiment 5 of the present invention. FIG. 11 is a schematic diagram of the surface of a CCD image sensor which is an example of a solid-state imaging device. 12 is a diagram showing the structure of the cross section along the line XX ′ of FIG. 11, and FIG. 12A shows the case where the optical axis of the optical waveguide and the optical axis of the lens coincide with each other. (B) has shown the case where the optical axis of an optical waveguide and the optical axis of a lens have shifted | deviated. FIG. 13 is a diagram for explaining a conventional method for manufacturing a solid-state imaging device, and FIGS. 13A to 13F show cross-sectional structures in main steps in the manufacturing method.

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

(Embodiment 1)
FIG. 1 is a diagram for explaining the structure of a solid-state imaging device according to an embodiment of the present invention. FIG. 1A is a plan view showing the structure of a portion corresponding to one pixel, and FIG. FIG. 1C is a cross-sectional view showing the structure of the cross section taken along the line AA ′ of FIG. 1, and FIG. 1C is a cross-sectional view showing the structure of the cross section taken along the line BB ′ of FIG.

  As shown in FIG. 1, the solid-state imaging device 1a according to the first embodiment has a pixel array in which a plurality of pixels are arranged in a matrix like the conventional solid-state imaging device shown in FIG. Is a solid-state imaging device that outputs a subject image signal.

  That is, the solid-state imaging device 1a is formed for each pixel on the semiconductor substrate 10, the semiconductor substrate, and the photoelectric conversion unit 11 that photoelectrically converts incident light, and the photoelectric conversion unit on the semiconductor substrate so as to face the photoelectric conversion unit. A condensing lens 24 that is arranged for each pixel and collects the incident light, and is arranged for each pixel so as to be positioned between the photoelectric conversion unit and the condensing lens, and is condensed by the condensing lens. A light guide 22a that guides the incident light to the photoelectric conversion unit, and the condensing lens 24 and the light guide 22a have a cross-sectional shape of a portion where the optical axes (center axes) thereof are in contact with each other It is positioned by.

  Further, an interlayer insulating film 20 is formed on the semiconductor substrate 10 so as to cover the side surface of the optical waveguide 22a. The optical waveguide 22a and the condenser lens 24 have a refractive index of the interlayer insulating film 20. It has a high refractive index.

  Further, the upper surface of the optical waveguide 22a in contact with the condenser lens 24 has a convex cross-sectional shape, and the lower surface of the condenser lens 24 in contact with the optical waveguide 22a is a convex sectional shape of the upper surface of the optical waveguide. The optical waveguide and the condensing lens are integrally formed with their contact surfaces engaging with each other. Here, the condensing lens 24 is disposed immediately above the optical waveguide 22a so that the apex thereof is located on the central axis of the optical waveguide.

  In addition, the solid-state imaging device 1a has a charge transfer unit (see the charge transfer unit 140 in FIG. 11) that transfers signal charges obtained by photoelectric conversion of incident light in each pixel. The transfer electrode (gate electrode) 16 constituting the charge transfer portion is formed, and the conductive layer constituting the gate electrode has a planar shape surrounding the photoelectric conversion portion of each pixel and has a constant thickness. The optical waveguide 22a and the condensing lens 24 in each pixel are positioned in a self-aligned manner according to the planar shape of the interlayer insulating film 20 covering the conductor layer constituting the gate electrode 16.

  Further, a transfer channel 13 constituting a charge transfer unit is formed on the semiconductor substrate 10 via a channel stop 12, and a read gate 14 is formed on the opposite side of the transfer channel 13 from the channel stop 12. ing.

  An insulating film 15 is formed on the semiconductor substrate 10, and a transfer electrode (gate electrode) 16 and an antireflection film 18 are formed on the insulating film 15. A light shielding film 18 is formed on the transfer electrode 16 via a first interlayer insulating film 17. A second interlayer insulating film 20 is formed on the light shielding film 18. An optical waveguide material 22 is formed on the antireflection film 18, and a condenser lens 24 is formed on the optical waveguide material 22.

  In the solid-state imaging device 1a according to the first embodiment, since the apex of the condensing lens 24 is arranged immediately above the central axis of the optical waveguide 22a, a condensing lens-integrated optical waveguide with no optical axis deviation is provided. It is possible to obtain a stable light collection rate.

  It is desirable that the refractive index of the optical waveguide 22 and the condensing lens 24 be the same, or that the condensing lens be higher. For example, the refractive index of the optical waveguide 22 can be 1.8, and the refractive index of the condenser lens 24 can be 2.0.

  Next, a manufacturing method will be described.

  FIG. 2 is a diagram for explaining a method for manufacturing a solid-state imaging device according to Embodiment 1 of the present invention, and FIGS. 2A to 2G show cross-sectional structures in main steps in this manufacturing method. Yes.

  First, processing until the cross-sectional structure shown in FIG.

  A photoelectric conversion unit 11, a channel stop 12, a charge transfer unit 13, and a readout gate 14 are formed on the surface of a semiconductor substrate 10 made of silicon by ion implantation. On the surface of the semiconductor substrate 10, an insulating film 15, which is a silicon oxide film having a thickness of 100 to 3000 nm, is formed by silicon thermal oxidation or CVD.

  Next, for example, a polysilicon film is deposited to a thickness of about 50 to 300 nm by a CVD method. Further, an n-type impurity such as phosphorus is introduced into the polysilicon film by thermal diffusion or ion implantation. Thereafter, the transfer film (gate electrode) 16 is formed by patterning the polysilicon film by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask by photolithography. Next, a first interlayer insulating film 17 is formed by oxide film deposition by polysilicon oxidation or CVD.

  Next, for example, a silicon nitride film is deposited as an antireflection film, and the antireflection film 18 is formed by patterning the silicon nitride film by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask. . Next, tungsten or the like which is a light shielding film material is deposited, and a light shielding film 19 is formed by a photolithography technique.

  Thereafter, a second interlayer insulating film 20 that is a silicon oxide film is formed on the entire surface by a CVD method so that the base step is flattened.

  Subsequently, processes for obtaining the cross-sectional structures shown in FIGS. 2B to 2G will be sequentially described.

  After the cross-sectional structure shown in FIG. 2A is obtained, as shown in FIG. 2B, the second interlayer insulating film 20 is masked with the photoresist 21 patterned into a predetermined pattern by photolithography as shown in FIG. Is anisotropically etched to form a region where the optical waveguide is to be disposed.

  Next, as shown in FIG. 2C, an optical waveguide material 22 that is a silicon nitride film having a thickness of 100 to 1000 nm is formed by a CVD method.

  Next, as shown in FIG. 2D, an organic antireflection film or the like is deposited as a sacrificial film 23 on the optical waveguide material to a thickness of about 100 to 1000 nm so as to have a flat upper surface by coating or the like.

Thereafter, as shown in FIG. 2E, the sacrificial film 23 and the optical waveguide 22 material are etched by a dry etching technique. For example, a CH ₄ CH ₃ + Ar-based gas is used as the etching gas. At this time, the conical optical waveguide 22 is obtained by making the etching rate of the optical waveguide 22 material faster than the etching rate of the sacrificial film 23 (see FIG. 2F).

  Next, as shown in FIG. 2G, a condensing lens material, for example, a silicon nitride film having a thickness of 100 to 1000 nm is formed by a CVD method. Thereby, an upward convex condensing lens 24 is formed around the apex of the conical optical waveguide 22a.

  In the first embodiment having such a configuration, the condensing lens and the optical waveguide are positioned according to the cross-sectional shape of the portion in contact with each other so that the central axes thereof coincide with each other. Therefore, the concentrating lens and the optical waveguide are inexpensive and have high controllability. A solid-state imaging device having an optical waveguide integrated with an optical lens can be obtained.

  In addition, since the position of the condensing lens is automatically determined with respect to the optical waveguide without being affected by the photoalignment deviation, it is possible to obtain a condensing lens-integrated optical waveguide in which the optical axis is not displaced more stably. The light rate is obtained.

  In this embodiment, the refractive index of the optical waveguide and the condensing lens is determined so that the light incident on the optical waveguide from the condensing lens is in accordance with the cross-sectional shape of the contact surface between the optical waveguide and the condensing lens. By setting to refract in a direction away from the optical axis of the optical waveguide, the incident angle of light incident on the photoelectric conversion unit through the condenser lens and the optical waveguide is more perpendicular to the surface of the photoelectric conversion unit. Smear can be reduced.

  In addition, such an optical waveguide integrated with a condensing lens is a self-aligned central axis (optical axis) of the condensing lens and the optical waveguide due to a step structure on the surface of the semiconductor substrate for positioning the optical waveguide on the semiconductor substrate. (Shaft) can be formed by a simple manufacturing method, and thus the cost can be reduced.

(Embodiment 2)
FIG. 3 is a diagram for explaining the structure of a solid-state imaging device according to Embodiment 2 of the present invention. FIG. 3A is a plan view showing the structure of a portion corresponding to one pixel in this solid-state imaging device. FIG. 3B is a cross-sectional view showing the structure of the CC ′ line cross section of FIG. 3, and FIG. 3C is a cross-sectional view showing the structure of the DD ′ line cross section of FIG.

  As shown in FIG. 3A, in the solid-state imaging device 1b according to the second embodiment, the photoelectric conversion unit 11 corresponding to each pixel is formed on the semiconductor substrate 10 like the solid-state imaging device 1a according to the first embodiment. In the vicinity of the photoelectric conversion unit 11, a charge transfer unit 13 is formed via a channel stop 12, and a readout gate 14 is formed on the side opposite to the channel stop.

  An insulating film 15 is formed on the semiconductor substrate 10, and a transfer electrode 16 and an antireflection film 18 are formed on the insulating film 15. A light shielding film 19 is formed on the transfer electrode 16 via a first interlayer insulating film 17. A dummy insulating film (sacrificial layer) 25 is formed on the light shielding film 19, and a second interlayer insulating film 20 a is further formed on the dummy insulating film 25. An optical waveguide 22b is formed on the antireflection film 18, and a condensing lens 24 is formed on the optical waveguide 22b.

  In the second embodiment, since the dummy insulating film 25 is formed, the optical waveguide 22b can be embedded in the dummy insulating film 25 in a self-aligned manner. Therefore, the optical waveguide 22b is provided on both sides of the photoelectric conversion unit. The dummy insulating film 25 can be disposed without being shifted in the middle position.

  Next, a manufacturing method will be described.

  4A and 4B are diagrams for explaining a method of manufacturing a solid-state imaging device according to Embodiment 2 of the present invention. FIGS. 4A to 4G show cross-sectional structures in main steps of the manufacturing method. Yes.

  First, processing until the cross-sectional structure shown in FIG.

  A photoelectric conversion unit 11, a channel stop 12, a charge transfer unit 13, and a readout gate 14 are formed on the surface of a semiconductor substrate 10 made of silicon by ion implantation. On the surface of the semiconductor substrate 10, an insulating film 15, which is a silicon oxide film having a thickness of 100 to 3000 nm, is formed by silicon thermal oxidation or CVD.

  Next, for example, a polysilicon film is deposited to a thickness of about 50 to 300 nm by a CVD method. Further, an n-type impurity such as phosphorus is introduced into the polysilicon film by thermal diffusion or ion implantation. Thereafter, the polysilicon film is patterned by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask by the photolithography technique to form the transfer electrode 16. Next, a first interlayer insulating film 17 is formed by depositing an oxide film by polysilicon oxidation or CVD.

  Next, for example, a silicon nitride film is deposited as an antireflection film, and the antireflection film 18 is formed by patterning the silicon nitride film by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask. .

  Next, tungsten or the like which is a light shielding film material is deposited, and a light shielding film 19 is formed by a photolithography technique. Next, an insulating film made of, for example, a silicon oxide film having a thickness of 100 to 1000 nm is deposited on the light shielding film 19 to a thickness of 1000 to 10000 angstrom by a CVD method, and a dummy insulating film 25 is formed by a photolithography technique. . The dummy insulating film 25 is desirably smaller than the width of the light shielding film 19 covering the lower transfer electrode 16.

  Subsequently, processes for obtaining the cross-sectional structures shown in FIGS. 4B to 4G will be sequentially described.

  After the cross-sectional structure shown in FIG. 4A is obtained, as shown in FIG. 4B, a second interlayer insulating film 20a, which is a silicon oxide film, is formed by CVD to a thickness of 1000 to 3000 angstroms. . Since the dummy insulating film 25 is formed on the transfer gate, the second interlayer insulating film 20 is formed in a forward taper, so that the optical waveguide shape can be automatically formed.

  Next, as shown in FIG. 4C, an optical waveguide material 22 which is a silicon nitride film having a thickness of 100 to 1000 nm is formed by a CVD method.

  Next, as shown in FIG. 4D, an organic antireflection film or the like is deposited as a sacrificial film 23 on the optical waveguide material 22 to a thickness of about 100 to 1000 nm so as to have a flat upper surface by coating or the like.

Thereafter, as shown in FIG. 4E, the sacrificial film 23 and the optical waveguide material 22 are etched by a dry etching technique. For example, a CH ₄ CH ₃ + Ar-based gas is used as the etching gas. At this time, the conical optical waveguide 22b is obtained by making the etching rate of the optical waveguide material 22 faster than the etching rate of the sacrificial film 23 (see FIG. 4F).

  Next, as shown in FIG. 4G, a condensing lens material, for example, a silicon nitride film having a thickness of 100 to 1000 nm is formed by a CVD method. Thereby, an upward convex condensing lens 24 is formed around the apex of the conical optical waveguide 22b.

  In the second embodiment having such a configuration, similarly to the first embodiment, a solid-state imaging device having an optical waveguide integrated with a condensing lens having a low cost and high controllability can be obtained, and the influence of photoalignment deviation can be obtained. Since the position of the condensing lens is automatically determined with respect to the optical waveguide without receiving the light, a condensing lens-integrated optical waveguide with a more shifted optical axis can be obtained, and a stable condensing rate can be obtained.

  In the second embodiment, the position of the optical waveguide is determined in a self-aligned manner with respect to the gate electrode by the step formed by the gate electrode disposed so as to surround the photoelectric conversion unit, and the condenser lens is positioned with respect to the optical waveguide. In addition to being able to determine the position in a self-aligned manner, the position of the dummy insulating film 25 formed on the gate electrode by using a photolithography technique is adjusted with respect to the gate electrode, so that the center position of the photoelectric conversion unit The center position of the optical waveguide and the condensing lens can be adjusted.

  In addition, such an optical waveguide integrated with a condensing lens is a self-aligned central axis (optical axis) of the condensing lens and the optical waveguide due to a step structure on the surface of the semiconductor substrate for positioning the optical waveguide on the semiconductor substrate. (Axis) can be formed by a simple manufacturing method, and thus the cost can be reduced.

(Embodiment 3)
FIG. 5 is a diagram for explaining the structure of the solid-state imaging device according to the third embodiment of the present invention, and shows a cross-sectional structure of a portion corresponding to the cross section taken along the line CC ′ of FIG.

  The solid-state imaging device 1c according to the third embodiment is the same as the solid-state imaging device 1b according to the second embodiment. The other configurations are the same as those of the solid-state imaging device 1b of the second embodiment.

  Next, a manufacturing method will be described.

  6A and 6B are diagrams for explaining a method for manufacturing a solid-state imaging device according to Embodiment 3 of the present invention. FIGS. 6A to 6G show cross-sectional structures in main steps in the manufacturing method. Yes.

  First, processing until the cross-sectional structure shown in FIG.

  A photoelectric conversion unit 11, a channel stop 12, a charge transfer unit 13, and a readout gate 14 are formed on the surface of the semiconductor substrate 10 made of silicon by a process such as ion implantation. On the surface of the semiconductor substrate 10, an insulating film 15, which is a silicon oxide film having a thickness of 100 to 3000 nm, is formed by silicon thermal oxidation or CVD.

  Next, for example, a polysilicon film is deposited to a thickness of about 50 to 300 nm by a CVD method. Further, an n-type impurity such as phosphorus is introduced into the polysilicon film by thermal diffusion or ion implantation. Thereafter, the polysilicon film is patterned by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask by the photolithography technique to form the transfer electrode 16. Next, a first interlayer insulating film 17 is formed by depositing an oxide film by polysilicon oxidation or CVD.

  Next, for example, a silicon nitride film is deposited as an antireflection film, and the antireflection film 18 is formed by anisotropic etching using a photoresist patterned in a predetermined pattern as a mask.

  Next, tungsten or the like which is a light shielding film material is deposited, and a light shielding film 19 is formed by a photolithography technique. Next, an insulating film, for example, a silicon oxide film having a thickness of 100 to 1000 nm is deposited on the light shielding film 19 by a CVD method, and a dummy insulating film 25 is formed by a photolithography technique. The dummy insulating film 25 is desirably smaller than the width of the light shielding film 19 covering the lower transfer electrode 16. Further, the dummy insulating film 25 is arranged so as to be shifted from the lower transfer electrode 16.

  Subsequently, processing for obtaining the cross-sectional structures shown in FIGS. 6B to 6G will be sequentially described.

  After the cross-sectional structure shown in FIG. 6A is obtained, as shown in FIG. 6B, a second interlayer insulating film 20 that is a silicon oxide film is formed by a CVD method. Since the dummy insulating film 25 is formed on the transfer gate, the second interlayer insulating film 20 is formed in a forward taper, so that a space for automatically arranging the optical waveguide can be formed.

  Next, as shown in FIG. 6C, an optical waveguide material 22, which is a silicon nitride film having a thickness of 100 to 1000 nm, is formed by a CVD method.

  Next, as shown in FIG. 6D, an organic antireflection film or the like is deposited as a sacrificial film 23 on the optical waveguide material 22 to a thickness of about 100 to 1000 nm so as to have a flat upper surface by coating or the like.

Thereafter, as shown in FIG. 6E, the sacrificial film 23 and the optical waveguide material 22 are etched by a dry etching technique. For example, a CH ₄ CH ₃ + Ar-based gas is used as the etching gas. At this time, the conical optical waveguide 22c is obtained by making the etching rate of the optical waveguide material 22 faster than the etching rate of the sacrificial film 23 (see FIG. 6F). This conical apex is formed at the center of the dummy insulating film 25 and can be shifted from the center position between the opposing transfer gates.

  Next, as shown in FIG. 6G, a condensing lens material, for example, a silicon nitride film having a thickness of 100 to 1000 nm is formed by a CVD method. As a result, an upward convex condensing lens 24 is formed around the apex of the conical optical waveguide 22c. Since the apex of the optical waveguide 22c is displaced from the center position of the opposing gate electrode, the optical waveguide 22c integrated with the condensing lens 24 can have an optical axis inclined.

  In the third embodiment having such a configuration, in addition to the effects of the second embodiment, as shown in FIG. 5, the dummy insulating film 25 is arranged so as to be shifted from the photodiode (photoelectric conversion unit). The center of the optical waveguide 22c can be shifted, and a shape with high light collection efficiency can be obtained for oblique light.

(Embodiment 4)
FIG. 7 is a diagram for explaining the structure of a solid-state imaging device according to Embodiment 4 of the present invention, and is a schematic diagram schematically showing the overall configuration.

  8 and 9 are diagrams showing a cross-sectional structure of the solid-state imaging device shown in FIG. 7 at a predetermined portion.

  8A, FIG. 8B, and FIG. 8C show the structures of the Lx-Lx ′ cross section, the Mx-Mx ′ cross section, and the Rx-Rx ′ cross section of FIG. 7, respectively, and FIG. 8E and FIG. 8F show the structures of the Ly-Ly ′ cross section, the My-My ′ cross section, and the Ry-Ry ′ cross section.

  9A, 9B, and 9C show the structures of the Uy-Uy ′, My-My ′, and By-By ′ sections of FIG. FIG. 9D, FIG. 9E, and FIG. 9F show the structures of the Uy-Uy ′ cross section, My-My ′ cross section, and By-By ′ cross section.

  In the figure, 2 is a semiconductor substrate on which a pixel array is formed, 3 is a photoelectric conversion unit, 4 is a vertical charge transfer unit, 5 is a horizontal charge transfer unit, and 6 is an amplifier, which are shown in FIG. The semiconductor substrate, the photoelectric conversion unit 111, the vertical charge transfer unit 140, the horizontal charge transfer unit 150, and the amplifier 160 are the same.

  In the solid-state imaging device 1d according to the fourth embodiment, in the solid-state imaging device 1b according to the second embodiment, the vertex of the condenser lens 24 is on the central axis of the optical waveguide 22b in the region other than the peripheral portion of the pixel array. The condenser lens 24 is arranged immediately above the optical waveguide 22b so as to be positioned, and the apex of the condenser lens and the center of the photoelectric conversion unit are arranged outside the pixel array at the periphery of the pixel array. The vertexes are arranged off the central axis of the optical waveguide 22b so as to be positioned along the optical axis of obliquely incident light incident obliquely on the pixels of the pixel array. Other points are the same as those of the solid-state imaging device of the second embodiment.

  That is, in the region other than the peripheral portion of the pixel array, specifically, in the pixel MP at the center portion of the pixel array, as shown in FIGS. Is disposed immediately above the optical waveguide 22b so as to be positioned on the central axis of the optical waveguide 22b.

  Further, in the peripheral portion of the pixel array, for example, the pixel LP on the left side of the pixel array, as shown in FIG. 8A, the condenser lens 24 includes an apex of the condenser lens and the photoelectric conversion unit. Is shifted from the center axis of the optical waveguide 22b to the left side so that the center of the optical waveguide 22b is located along the optical axis of the obliquely incident light incident obliquely on the pixels of the pixel array from the outside of the pixel array. Has been placed.

  Further, in the pixel RP on the right side of the pixel array, as shown in FIG. 8C, the condenser lens 24 includes an apex of the condenser lens and a center of the photoelectric conversion unit. The apex is shifted from the center axis of the optical waveguide 22b to the right side so as to be positioned along the optical axis of the obliquely incident light that is obliquely incident on the pixels of the pixel array from the outside.

  However, since the pixels LP and RP are located in the center in the vertical direction of the pixel array, the condenser lens 24 is arranged without being shifted in the vertical direction with respect to the central axis of the optical waveguide 22b. Yes.

  Further, in the pixel UP on the upper side portion of the pixel array, as shown in FIG. 9A, the condensing lens 24 has an apex of the condensing lens and a center of the photoelectric conversion unit. The apex is shifted from the central axis of the optical waveguide 22b to the upper side so as to be positioned along the optical axis of the obliquely incident light incident obliquely on the pixels of the pixel array from the outside.

  Further, in the pixel BP on the lower side portion of the pixel array, as shown in FIG. 9C, the condenser lens 24 includes the vertex of the condenser lens and the center of the photoelectric conversion unit. The apex is shifted from the center axis of the optical waveguide 22b to the lower side so as to be positioned along the optical axis of the obliquely incident light incident obliquely on the pixels of the pixel array from the outside.

  However, since the pixels UP and BP are located in the center in the horizontal direction in the pixel array, the condenser lens 24 is arranged without being shifted in the left-right direction with respect to the central axis of the optical waveguide 22b. Yes.

  In the solid-state imaging device 1d according to the fourth embodiment having such a configuration, the positional relationship between the optical waveguide and the condensing lens can be optimized according to the position of each pixel in the pixel array, and the condensing rate of the solid-state imaging device Can be maximized.

Furthermore, although not specifically described in the first to fourth embodiments, a digital camera such as a digital video camera or a digital still camera using at least one of the solid-state imaging devices of the first to fourth embodiments as an imaging unit. An electronic information device having an image input device, such as an image input camera, a scanner, a facsimile machine, or a camera-equipped mobile phone, will be briefly described below.
(Embodiment 5)
FIG. 10 is a block diagram illustrating a schematic configuration example of an electronic information device using the solid-state imaging device according to any one of Embodiments 1 to 4 as an imaging unit as Embodiment 5 of the present invention.

  An electronic information device 90 according to Embodiment 5 of the present invention shown in FIG. 10 includes at least one of the solid-state imaging devices according to Embodiments 1 to 4 of the present invention as an imaging unit 91 that captures a subject. A memory unit 92 such as a recording medium for recording data after high-definition image data obtained by photographing by such an image pickup unit is subjected to predetermined signal processing for recording, and predetermined signal processing for displaying the image data A display unit 93 such as a liquid crystal display device that displays on a display screen such as a liquid crystal display screen, and a communication unit 94 such as a transmission / reception device that performs communication processing after performing predetermined signal processing on the image data for communication. And an image output unit 95 that prints (prints) image data and outputs (prints out) the image data.

  Further, as an embodiment of the present invention, a CCD image sensor has been described as a solid-state imaging device. However, the present invention can be applied not only to a CCD image sensor but also to a CMOS image sensor, and further to a linear image. A sensor or other semiconductor device, which is disposed between a photoelectric conversion unit that photoelectrically converts incident light, a condensing lens that condenses incident light on the photoelectric conversion unit, and the photoelectric conversion unit and the condensing lens Any semiconductor device having an optical waveguide that guides incident light collected by the condenser lens to the photoelectric conversion unit can be applied.

  As described above, the present invention has been exemplified using the preferred embodiments of the present invention, but the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention, and the scope of the present invention is interpreted only by the claims. It is understood that it should be. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  Since the solid-state imaging device of the present invention has a high light collection rate, it is particularly suitably used as a high-resolution imaging device such as a digital camera such as a digital video camera and a digital still camera, or a surveillance camera. Moreover, the manufacturing method of the solid-state image sensor of this invention is utilized suitably for the objective of manufacturing the solid-state image sensor of this invention.

1a to 1d Solid-state imaging device 10, 110 Semiconductor substrate 11, 111 Photoelectric conversion unit 12, 112 Channel stop 13, 113 Charge transfer unit 14, 114 Read gate 15, 115 Insulating film 16, 116 Transfer electrode (gate electrode)
17, 117 First interlayer insulating film 18, 118 Antireflection film 19, 119 Light shielding film 20, 120 Second interlayer insulating film 21, 121 Photoresist 22a, 22b, 22c, 122a Optical waveguide 23 Sacrificial film 24, 124 Condensing lens 25 Dummy insulating film 90 Electronic information device 91 Imaging unit 92 Memory unit 93 Display unit 94 Communication unit 95 Image output unit 140 Vertical transfer unit 150 Horizontal transfer unit 160 Amplifier

Claims (20)

A semiconductor device formed in a semiconductor substrate and having a photoelectric conversion unit that photoelectrically converts incident light,
A condensing lens that is disposed on the semiconductor substrate so as to face the photoelectric conversion unit and collects the incident light;
An optical waveguide disposed between the photoelectric conversion unit and the condensing lens, and guiding the incident light collected by the condensing lens to the photoelectric conversion unit,
The semiconductor device, wherein the condensing lens and the optical waveguide are positioned by a cross-sectional shape of a portion in contact with each other so that the respective central axes have a predetermined positional relationship. The semiconductor device according to claim 1,
The upper surface of the optical waveguide that contacts the condenser lens has a convex cross-sectional shape,
The cross-sectional shape of the lower surface of the condensing lens in contact with the optical waveguide has a concave cross-sectional shape that engages with the convex cross-sectional shape of the upper surface of the optical waveguide,
The semiconductor device, wherein the optical waveguide and the condenser lens are integrally formed. The semiconductor device according to claim 2,
The refractive index of the optical waveguide and the condensing lens is such that the light incident on the optical waveguide from the condensing lens is in accordance with the cross-sectional shape of the contact surface between the optical waveguide and the condensing lens. A semiconductor device configured to be refracted in a direction away from the semiconductor device. The semiconductor device according to claim 2,
A semiconductor device in which a refractive index of the optical waveguide is equal to a refractive index of the condenser lens. The semiconductor device according to claim 3.
The cross-sectional shape of the contact surface between the optical waveguide and the condensing lens is a substantially isosceles triangular shape whose apex is located on the optical axis of the optical waveguide and symmetric with respect to the optical axis,
The hypotenuses located on both sides of the optical axis are curved downward,
A semiconductor device, wherein a refractive index of the optical waveguide is smaller than a refractive index of the condenser lens. A solid-state imaging device having a pixel array in which a plurality of pixels are arranged in a matrix, photoelectrically converting incident light in each pixel and outputting an image signal of a subject,
A photoelectric conversion unit that is formed for each pixel on a semiconductor substrate and photoelectrically converts incident light;
A condensing lens that is arranged for each pixel so as to face the photoelectric conversion unit on the semiconductor substrate and collects the incident light;
An optical waveguide that is arranged for each pixel so as to be positioned between the photoelectric conversion unit and the condensing lens, and that guides incident light collected by the condensing lens to the photoelectric conversion unit,
The solid-state imaging device, wherein the condensing lens and the optical waveguide are positioned according to a cross-sectional shape of a portion where they are in contact with each other so that their optical axes coincide with each other. The solid-state imaging device according to claim 6,
A solid-state imaging device in which a refractive index of the condensing lens is the same as or higher than a refractive index of the optical waveguide. The solid-state imaging device according to claim 6,
On the semiconductor substrate, an interlayer insulating film is formed so as to cover the side surface of the optical waveguide,
The solid-state imaging device, wherein the optical waveguide and the condenser lens have a refractive index higher than that of the interlayer insulating film. The solid-state imaging device according to claim 6,
The upper surface of the optical waveguide that contacts the condenser lens has a convex cross-sectional shape,
The lower surface of the condensing lens in contact with the optical waveguide has a concave cross-sectional shape that engages with the convex cross-sectional shape of the upper surface of the optical waveguide;
A solid-state imaging device in which the optical waveguide and the condenser lens are formed integrally. The solid-state imaging device according to claim 9,
The solid-state imaging device, wherein the condensing lens is disposed immediately above the optical waveguide so that a vertex thereof is located on a central axis of the optical waveguide. The solid-state imaging device according to claim 9,
The solid-state imaging device, wherein the condenser lens is arranged so as to be shifted from a position immediately above the optical waveguide so that a vertex thereof is located at a position deviating from a central axis of the optical waveguide. The solid-state imaging device according to claim 9,
In a region other than the peripheral portion of the pixel array, the condenser lens is disposed immediately above the optical waveguide so that the apex thereof is located on the central axis of the optical waveguide,
In the peripheral part of the pixel array, the condenser lens has an oblique incident light in which the vertex of the condenser lens and the center of the photoelectric converter are obliquely incident on the pixels of the pixel array from the outside of the pixel array. A solid-state imaging device arranged so that its apex is removed from the central axis of the optical waveguide so as to be positioned along the optical axis. The solid-state imaging device according to claim 6,
Each pixel has a charge transfer unit that transfers a signal charge obtained by photoelectric conversion of incident light,
On the semiconductor substrate, a gate electrode constituting the charge transfer portion is formed,
The conductive layer constituting the gate electrode has a planar shape surrounding the photoelectric conversion portion of each pixel and has a certain thickness.
The solid-state imaging device, wherein the optical waveguide and the condensing lens in each pixel are positioned in a self-aligned manner by a planar shape of a conductor layer constituting the gate electrode. The solid-state imaging device according to claim 13,
A sacrificial layer for adjusting the positions of the optical waveguide and the condensing lens, which are positioned in a self-aligned manner by the planar shape of the conductive layer, is formed on the conductive layer constituting the gate electrode by photolithography. A solid-state imaging device. The solid-state imaging device according to claim 14,
The solid-state imaging device, wherein the gate electrode is a transfer gate electrode constituting a vertical charge transfer unit that transfers the signal charge in a vertical direction. A condensing lens corresponding to each pixel; and an optical waveguide that guides light from the condensing lens to a photoelectric conversion unit of the corresponding pixel, and the condensing lens and the optical waveguide are positioned in a self-aligned manner. A method of manufacturing a solid-state imaging device,
After forming a photoelectric conversion portion constituting the pixel and a transfer gate electrode for transferring a signal charge generated by the photoelectric conversion portion in the semiconductor substrate, an entire surface of the semiconductor substrate is formed through an insulating film. Forming an optical waveguide material layer so that the step is reflected;
Laminating a sacrificial layer having an etching rate lower than that of the optical waveguide material layer on the optical waveguide material layer;
Etching the optical waveguide material layer and the sacrificial film simultaneously to form an optical waveguide having a cross-sectional shape determined by a step on the surface of the semiconductor substrate;
Forming a condensing lens above the optical waveguide in a self-aligned manner by the cross-sectional shape of the optical waveguide. In the manufacturing method of the solid-state image sensing device according to claim 16,
Forming the insulating film using a photolithography process;
The step of forming the insulating film includes
Forming an insulating material layer on the entire surface of the semiconductor substrate;
And a step of patterning the insulating material layer so as to cover the gate electrode to form the insulating film. In the manufacturing method of the solid-state image sensing device according to claim 16,
Forming a sacrificial layer on the gate electrode using a photolithography process;
The step of forming the insulating film includes
The manufacturing method of a solid-state image sensor including the process of forming an insulating material layer along the surface of the said photoelectric conversion part, this gate electrode, and this sacrificial layer. In the manufacturing method of the solid-state image sensing device according to claim 16,
The method of manufacturing a solid-state imaging device, wherein the sacrificial layer is patterned so that a center axis of the optical waveguide is shifted from a center position between the gate electrodes located on both sides of the photoelectric conversion unit. An electronic information device having an imaging unit for imaging a subject,
The electronic information device, wherein the imaging unit is a solid-state imaging device according to any one of claims 6 to 15.