JPWO2014021130A1 - Solid-state imaging device, method for manufacturing solid-state imaging device, and electronic apparatus - Google Patents

Abstract

The present technology relates to a solid-state imaging device, a manufacturing method of the solid-state imaging device, and an electronic apparatus that can optimize the sensitivity of each photoelectric conversion unit according to the wavelength of incident light. The solid-state imaging device includes a semiconductor substrate having a plurality of photoelectric conversion units, a protective layer, a light shielding film, an antireflection adjustment layer, a color filter, and a wiring layer. The protective layer is provided directly on the light receiving surface of the semiconductor substrate so as to cover the entire surface of the light receiving surface. The light shielding film is provided on the protective layer and shields light between the photoelectric conversion units. The antireflection adjusting layer is provided on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and has a stepped shape that is thinned corresponding to a predetermined photoelectric conversion unit. The color filter is provided on the antireflection adjustment layer in an arrangement corresponding to the photoelectric conversion unit, and has each color pattern corresponding to the film thickness of the antireflection adjustment layer. The wiring layer is provided on the side opposite to the light receiving surface of the semiconductor substrate.

Description

  The present technology relates to a solid-state imaging device, a method for manufacturing a solid-state imaging device, and an electronic apparatus, and in particular, a solid-state imaging device having an antireflection adjustment layer, a manufacturing method for the solid-state imaging device, and an electronic device using the solid-state imaging device. Related to equipment.

  The solid-state imaging device has a semiconductor substrate on which a plurality of photoelectric conversion units are arranged, an antireflection adjustment layer is provided on the semiconductor substrate, and a pattern composed of a plurality of colors is formed on the antireflection adjustment layer. A color filter is provided. Incident light to the solid-state imaging device is separated into light having different wavelengths such as red, green, and blue by a color filter, and is incident on each photoelectric conversion unit.

  In such a solid-state imaging device, the film thickness of the antireflection adjusting layer is set according to the pattern of the color filter, that is, according to the wavelength of light incident on the photoelectric conversion unit, thereby improving the sensitivity of the solid-state imaging device. Technology is disclosed.

  For example, a solid-state imaging device includes a semiconductor substrate including a plurality of photoelectric conversion elements, an antireflection film laminated on a light receiving surface of the semiconductor substrate, and a color filter having a predetermined arrangement pattern laminated on the antireflection film. . In this solid-state imaging device, a photoelectric conversion element in which a color filter of a specific color is stacked is used as an antireflection film removing element, and the antireflection film is removed from the entire surface of the light receiving surface of the antireflection removing element (the following patent document) 1).

JP2011-216730A

  However, in the solid-state imaging device having such a configuration, the antireflection film laminated on the light receiving surface of the semiconductor substrate has a portion corresponding to the antireflection removing element removed, that is, laminated on the light receiving surface of the semiconductor substrate. An antireflection film is patterned. When patterning the antireflection film laminated on the light receiving surface of the semiconductor substrate, resist contamination and damage are likely to occur on the light receiving surface, so that the white spot and dark current are likely to deteriorate in the antireflection removal element.

  Therefore, the present technology provides a solid-state imaging device having an antireflection adjustment layer provided without deteriorating white spots and dark current, and in which the sensitivity of each photoelectric conversion unit is optimized according to the wavelength of incident light. This is the issue.

  In order to achieve such an object, a solid-state imaging device of the present technology includes a semiconductor substrate having a plurality of photoelectric conversion units, a protective layer, a light shielding film, an antireflection adjustment layer, a color filter, and a wiring layer. Prepare. The protective layer is provided directly on the light receiving surface of the semiconductor substrate so as to cover the entire surface of the light receiving surface. The light shielding film is provided on the protective layer and shields light between the photoelectric conversion units. The antireflection adjusting layer is provided on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and has a stepped shape that is thinned corresponding to a predetermined photoelectric conversion unit. The color filter is provided on the antireflection adjustment layer in an arrangement corresponding to the photoelectric conversion unit, and has each color pattern corresponding to the film thickness of the antireflection adjustment layer. The wiring layer is provided on the side opposite to the light receiving surface of the semiconductor substrate.

  In the solid-state imaging device having such a configuration, the antireflection adjustment layer having a stepped shape corresponding to a predetermined photoelectric conversion unit is provided in a semiconductor via a protective layer provided so as to cover the entire surface of the light receiving surface. It is the structure provided on the light-receiving surface of a board | substrate. For this reason, when the antireflection adjusting layer formed on the light receiving surface via the protective layer is patterned into a step shape, patterning damage does not reach the light receiving surface of the semiconductor substrate.

  The present technology is also a method for manufacturing such a solid-state imaging device, and the following procedure is performed. First, a protective layer that covers the entire surface of the light receiving surface is formed immediately above the light receiving surface of the semiconductor substrate having a plurality of photoelectric conversion portions. A light shielding film that shields light between the photoelectric conversion portions is formed on the protective layer. Further, an antireflection adjustment layer is formed on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and the formed antireflection adjustment layer is thinned corresponding to a predetermined photoelectric conversion portion. To pattern. Then, the color filter which has each color pattern corresponding to the film thickness of an antireflection adjustment layer is formed by arrangement | positioning corresponding to a photoelectric conversion part on an antireflection adjustment layer. A wiring layer is formed on the side opposite to the light receiving surface of the semiconductor substrate.

  The present technology is also an electronic device including the above-described solid-state imaging device, and further includes an optical system that guides incident light to the photoelectric conversion unit.

  In the present technology described above, in the solid-state imaging device including the antireflection adjustment layer having a stepped shape corresponding to a predetermined photoelectric conversion unit, the damage due to the patterning of the antireflection adjustment layer is a light receiving surface of the semiconductor substrate. Therefore, it is possible to prevent the white spot and the dark current from deteriorating. Therefore, in a solid-state imaging device having an antireflection adjustment layer, the sensitivity of each photoelectric conversion unit should be optimized according to the wavelength of incident light dispersed by the color fill without deteriorating the white spot and dark current. Is possible.

It is a schematic block diagram of the solid-state imaging device to which this technique is applied. It is principal part sectional drawing which shows the structure of the solid-state imaging device of 1st Embodiment. It is sectional process drawing (1) which shows the manufacturing method of the solid-state imaging device of 1st Embodiment. It is sectional process drawing (2) which shows the manufacturing method of the solid-state imaging device of 1st Embodiment. It is sectional process drawing (3) which shows the manufacturing method of the solid-state imaging device of 1st Embodiment. It is a graph regarding the solid-state imaging device of the first embodiment. It is principal part sectional drawing which shows the structure of the solid-state imaging device of the modification 1 of 1st Embodiment. It is principal part sectional drawing which shows the structure of the solid-state imaging device of the modification 2 of 1st Embodiment. It is principal part sectional drawing which shows the structure of the solid-state imaging device of 2nd Embodiment. It is sectional process drawing (1) which shows the manufacturing method of the solid-state imaging device of 2nd Embodiment. It is sectional process drawing (2) which shows the manufacturing method of the solid-state imaging device of 2nd Embodiment. It is principal part sectional drawing which shows the structure of the solid-state imaging device of the modification 1 of 2nd Embodiment. It is principal part sectional drawing which shows the structure of the solid-state imaging device of 3rd Embodiment. It is a block diagram of the electronic device using the solid-state imaging device obtained by applying this technology.

Hereinafter, embodiments of the present technology will be described in the following order based on the drawings.
1. 1. Schematic configuration example of solid-state imaging device according to embodiment Solid-state imaging device according to the first embodiment (an example in which an antireflection adjustment layer is provided below the light shielding film)
3. Modification 1 of the first embodiment (example in which the color filter is provided only in the opening of the light shielding film)
4). Modification 2 of the first embodiment (an example in which the antireflection adjusting layer has a stepped shape in which the thickness is reduced to two stages)
5. Solid-state imaging device according to the second embodiment (example in which an antireflection adjusting layer is provided on a light shielding film: Part 1)
6). Modified example 1 of the second embodiment (an example in which the antireflection adjusting layer has a laminated structure in which an upper layer and a lower layer of the light shielding film are provided)
7). Solid-state imaging device according to the third embodiment (example in which the antireflection adjusting layer is provided on the light shielding film: Part 2)
8). Fourth embodiment (an example of an electronic apparatus using a solid-state imaging device)
In addition, in each embodiment, the same code | symbol is attached | subjected to a common component, and the overlapping description is abbreviate | omitted.

<1. Schematic Configuration Example of Solid-State Imaging Device of Embodiment>
FIG. 1 shows a schematic configuration using a MOS solid-state imaging device as an example of a solid-state imaging device provided with the solid-state imaging device of the present technology.

  The solid-state imaging device 1 shown in this figure has a pixel region 4 in which a plurality of pixels 3 including a photoelectric conversion region are two-dimensionally arranged on one surface of a semiconductor substrate 11. Each pixel 3 arranged in the pixel region 4 is provided with a photoelectric conversion region, a floating diffusion, a read gate, a pixel circuit composed of a plurality of other transistors (so-called MOS transistors), a capacitive element, and the like. ing. A plurality of pixels 3 may share a part of the pixel circuit.

  Peripheral circuits such as a vertical drive circuit 5, a column signal processing circuit 6, a horizontal drive circuit 7, and a system control circuit 8 are provided in the peripheral portion of the pixel region 4 as described above.

  The vertical drive circuit 5 is configured by, for example, a shift register, selects the pixel drive line 9, supplies a pulse for driving the pixel 3 to the selected pixel drive line 9, and the pixels 3 arranged in the pixel region 4. Is driven line by line. That is, the vertical drive circuit 5 selectively scans each pixel arranged in the pixel region 4 in the vertical direction sequentially in units of rows. Then, the pixel signal based on the signal charge generated according to the amount of light received in each pixel 3 is supplied to the column signal processing circuit 6 through the vertical drive line 10 wired perpendicular to the pixel drive line 9.

  The column signal processing circuit 6 is arranged for each column of pixels, for example, and performs signal processing such as noise removal on the signal output from the pixels 3 for one row for each pixel column. That is, the column signal processing circuit 6 performs signals such as correlated double sampling (CDS), signal amplification, and analog / digital conversion (AD) to remove fixed pattern noise unique to the pixel. Process.

  The horizontal drive circuit 7 is configured by, for example, a shift register, and sequentially outputs horizontal scanning pulses, thereby selecting each of the column signal processing circuits 6 in order and outputting a pixel signal from each of the column signal processing circuits 6.

  The system control circuit 8 receives an input clock and data for instructing an operation mode, and outputs data such as internal information of the solid-state imaging device 1. That is, in the system control circuit 8, based on the vertical synchronization signal, the horizontal synchronization signal, and the master clock, the clock signal and the control signal that are the reference for the operation of the vertical drive circuit 5, the column signal processing circuit 6, the horizontal drive circuit 7, and the like. Is generated. These signals are input to the vertical drive circuit 5, the column signal processing circuit 6, the horizontal drive circuit 7, and the like.

  The peripheral circuits 5 to 8 as described above and the pixel circuit provided in the pixel region 4 constitute a drive circuit that drives each pixel. Note that the peripheral circuits 5 to 8 may be arranged at positions where they are stacked on the pixel region 4.

<2. Solid-State Imaging Device of First Embodiment>
(An example in which an antireflection adjusting layer is provided below the light shielding film)
FIG. 2 is a cross-sectional view of a main part showing the configuration of the solid-state imaging device according to the first embodiment. Hereinafter, the configuration of the solid-state imaging device 1-1 of the first embodiment will be described with reference to this drawing.

  As shown in FIG. 2, the solid-state imaging device 1-1 according to the first embodiment includes a semiconductor substrate 11 including a photoelectric conversion unit 12, and a protective layer 13 and antireflection adjustment are formed on a light receiving surface 11 a of the semiconductor substrate 11. The layer 14, the light shielding film 15, the adhesion layer 16, the color filter 17, and the on-chip lens 18 are laminated in this order. The solid-state imaging device 1-1 is a backside illumination type, and a wiring layer 19 is provided on the side opposite to the light receiving surface 11a of the semiconductor substrate 11.

  Among these, the antireflection adjusting layer 14 is characteristic and has a stepped shape that is thinned corresponding to a predetermined photoelectric conversion unit 12, and the stepped shape is patterned using the light shielding film 15 as a mask. It is. Further, in the solid-state imaging device 1-1, the antireflection adjusting layer 14 having such a step shape is formed on the light receiving surface 11a of the semiconductor substrate 11 via the protective layer 13 provided so as to cover the entire surface of the light receiving surface 11a. It is characteristic that it is provided. Further, it is characteristic that the color filter 17 is provided so as to be embedded between the light shielding films 15.

  Hereinafter, each structure is demonstrated in order of the semiconductor substrate 11, the photoelectric conversion part 12, the protective layer 13, the reflection prevention adjustment layer 14, the light shielding film 15, the contact | adherence layer 16, the color filter 17, the on-chip lens 18, and the wiring layer 19.

[Semiconductor substrate 11]
The semiconductor substrate 11 is made of a crystalline semiconductor, for example, a substrate made of single crystal silicon. In the semiconductor substrate 11, a plurality of photoelectric conversion units 12 are arranged along the light receiving surface 11a, and a floating diffusion (not shown) is provided on the interface opposite to the light receiving surface 11a.

[Photoelectric conversion unit 12]
The photoelectric conversion unit 12 is a pn junction photodiode (PD) including an n-type impurity region and a p-type impurity region. The photoelectric conversion unit 12 is provided for each pixel, and a plurality of the photoelectric conversion units 12 are two-dimensionally arranged in the semiconductor substrate 11 with respect to the light receiving surface 11a. Light separated by the color filter 17 is incident on the photoelectric conversion unit 12. For example, when the color filter 17 has RGB color patterns 17r, 17g, and 17b, red (R) light is supplied to the photoelectric conversion unit 12r (12), and green (G) light is supplied to the photoelectric conversion unit 12g (12). However, blue (B) light is incident on the photoelectric conversion unit 12b (12). In each photoelectric conversion unit 12, incident light is photoelectrically converted, and generated signal charges are accumulated.

[Protective layer 13]
The protective layer 13 covers the entire surface of the light receiving surface 11 a and is provided immediately above the light receiving surface 11 a of the semiconductor substrate 11, and is a layer that protects the light receiving surface 11 a of the semiconductor substrate 11. The protective layer 13 is a layer that is not patterned and has a flat surface, and has a uniform film thickness of about 10 to 50 nm. Moreover, the refractive index of the protective layer 13 is higher than the antireflection adjusting layer 14 as an example.

Such a protective layer 13 includes, for example, hafnium oxide (HfO), aluminum oxide (Al ₂ O ₃ ), tantalum oxide (TaO), tantalum pentoxide (Ta ₂ O ₅ ), silicon nitride (SiN), and silicon oxide. (Si ₂ O) or the like is used. Or you may be comprised by these laminated structures. The protective layer 13 made of these materials is a protective film for the semiconductor substrate 11. When these materials are used, the protective layer 13 also functions as a pinning layer for the semiconductor substrate 11.

[Antireflection Adjustment Layer 14]
The antireflection adjusting layer 14 is provided below the light shielding film 15 on the protective layer 13. The antireflection adjusting layer 14 has a stepped shape partially thinned corresponding to the predetermined photoelectric conversion unit 12, and the reflectance of each color light dispersed by the color filter 17 at each photoelectric conversion unit 12 is This is an antireflection layer that is adjusted to be minimized. The refractive index of the antireflection adjusting layer 14 is smaller than the refractive index of the color filter 17, for example, the refractive index n = 1.44 to 1.54. Thereby, the antireflection adjusting layer 14 functions as a multilayer antireflection film on the light receiving surface 11 a of the semiconductor substrate 11. The refractive index of the antireflection adjusting layer 14 is lower than the refractive index of the protective layer 13.

  Such an antireflection adjusting layer 14 is configured using, for example, an inorganic material such as silicon nitride (SiN) and silicon oxide (SiO), or an organic material such as acrylic and styrene. A single layer structure in which one material is selected from these materials, a single layer structure in which a plurality of materials are mixed, or a laminated structure may be used. As an example of the laminated structure, the antireflection adjusting layer 14 is made of a layered structure using materials having different selection ratios, and the lower layer is used as an etching stopper when etching to form a step shape in the antireflection adjusting layer 14. You can also.

  The antireflection adjusting layer 14 has a predetermined photoelectric property such that the larger the wavelength of light incident on the predetermined photoelectric conversion unit 12 through the color filter 17, the larger the film thickness of the portion corresponding to the photoelectric conversion unit 12. The step shape is partially thinned corresponding to the conversion unit 12. Here, the respective film thicknesses of the antireflection adjusting layer 14 in the thinned portions corresponding to the photoelectric conversion units 12r, 12g, and 12b are defined as film thicknesses Tr, Tg, and Tb. In this case, the film thicknesses Tr, Tg, and Tb are film thicknesses that can prevent reflection of light having a predetermined wavelength dispersed by the color filter 17, and these film thicknesses are 10 to 10 in consideration of the duration of light. Adjustment is made within a range of about 500 nm. In the present embodiment, the relationship between the film thicknesses Tr, Tg, and Tb is Tr> Tg> Tb according to the wavelength of incident light.

  Further, the step shape of the antireflection adjusting layer 14 is a step shape formed by etching using the light shielding film 15 as a mask. Therefore, the antireflection adjusting layer 14 has concave portions 14g and 14b having the same opening shape as the opening of the light shielding film 15, and the concave portions 14g and 14b are provided corresponding to the photoelectric conversion portions 12g and 12b. Since the antireflection adjusting layer 14 has the recesses 14g and 14b, as described above, the respective film thicknesses of the antireflection adjusting layer 14 corresponding to the photoelectric conversion units 12r, 12g, and 12b are Tr, Tg, and Tb. ing. Thereby, the antireflection adjusting layer 14 is partially thinned corresponding to each of the photoelectric conversion portions 12r, 12g, and 12b, and has a step shape in which the concave portions 14g and 14b are provided.

  In such an antireflection adjusting layer 14, the thickness of the portion covered with the light shielding film 15 as a mask, that is, the lower portion of the light shielding film 15 is equal. On the other hand, the film thickness of the patterning portion, that is, the opening portion of the light shielding film 15 differs according to the wavelength of light incident on the corresponding photoelectric conversion unit 12. The opening portion of the light shielding film 15 is made thinner than the portion covered with the light shielding film 15.

[Light shielding film 15]
The light shielding film 15 is a film that shields light between the photoelectric conversion units 12, and is provided on the antireflection adjustment layer 14 in a pattern that covers between the photoelectric conversion units 12 and opens on the photoelectric conversion unit 12. The light shielding film 15 is made of, for example, materials such as tungsten (W), tungsten oxide (WO), titanium (Ti), titanium nitride (TiN), and carbon black dispersion resin. A single layer structure in which one material is selected from these materials, a single layer structure in which a plurality of materials are mixed, or a laminated structure may be used.

[Adhesion layer 16]
The adhesion layer 16 is a layer having a uniform film thickness that covers the antireflection adjusting layer 14 and the light shielding film 15, and is a layer that improves the adhesion between the light shielding film 15 and the color filter 17. The adhesion layer 16 is preferably made of a material having a refractive index comparable to that of the antireflection adjusting layer 14, and may be made of the same material as that of the antireflection adjusting layer 14.

[Color filter 17]
The color filter 17 is provided in an arrangement corresponding to the photoelectric conversion unit 12 and has each color pattern corresponding to the film thickness of the antireflection adjusting layer 14. For example, as shown in FIG. 2, a color filter 17 having RGB color patterns 17r, 17g, and 17b is used. In this case, the R pattern 17r corresponds to the film thickness Tr of the antireflection adjustment layer 14, the G pattern 17g corresponds to the film thickness Tg of the antireflection adjustment layer 14, and the B pattern 17b corresponds to the film thickness Tb of the antireflection adjustment layer 14. Corresponding to The color filter 17 is provided via the adhesion layer 16 in a state where the space between the light shielding films 15 is embedded on the antireflection adjusting layer 14. Thereby, the light irradiated to the solid-state imaging device 1-1 is light having different wavelengths (for example, red, green, and blue) separated in each color pattern of the color filter 17, and the corresponding photoelectric conversion units 12 ( 12r, 12g, 12b).

  The color filter 17 preferably has a flattened surface. Thereby, it is not necessary to provide a planarizing layer as a base of an on-chip lens 18 to be described next.

  Such a color filter 17 is configured, for example, by adding a pigment using a metal complex or a polymer dye to an organic resin mainly composed of acrylic. Alternatively, a multilayer film may be used, and an example of the multilayer film is a stacked structure of inorganic materials such as silicon nitride (SiN) and silicon oxide (SiO).

[On-chip lens 18]
The on-chip lens 18 is provided on the color filter 17 having a flat surface so as to correspond to each photoelectric conversion unit 12, and is configured so that incident light is condensed on each photoelectric conversion unit 12.

[Wiring layer 19]
The wiring layer 19 is provided on the side opposite to the light receiving surface 11 a of the semiconductor substrate 11. A transfer gate (not shown) is provided on the interface side with the semiconductor substrate 11 via a gate insulating film, and other electrodes are provided, and these electrodes are covered with an interlayer insulating film (not shown). . The interlayer insulating film is provided with a plurality of wirings, and a part of the wiring is connected to the transfer gate and the floating diffusion in the semiconductor substrate 11. Such a wiring layer 19 forms part of a drive circuit that drives the pixels.

[Method for Manufacturing Solid-State Imaging Device 1-1]
3 to 5 are cross-sectional process diagrams for explaining the manufacturing method of the solid-state imaging device 1-1 of the first embodiment. Hereinafter, a method for manufacturing the solid-state imaging device 1-1 will be described based on these drawings.

  First, as shown in FIG. 3A, a plurality of photoelectric conversion units 12 are arrayed along the light receiving surface 11 a of the semiconductor substrate 11, and a floating diffusion (not shown) is formed in the semiconductor substrate 11. On the surface opposite to the light receiving surface 11a of the semiconductor substrate 11, a transfer gate and other gate electrodes (not shown) are formed through a gate insulating film, and these are covered with an interlayer insulating film, and the interlayer insulating film is formed. A multilayer wiring is formed. As a result, the wiring layer 19 is formed on the side of the semiconductor substrate 11 opposite to the light receiving surface 11a.

  Subsequently, the protective layer 13, the antireflection adjusting layer 14, and the light shielding film 15 are sequentially stacked on the light receiving surface 11 a of the semiconductor substrate 11. Of these, the protective layer 13 is made of, for example, hafnium oxide (HfO), and is formed with a film thickness of 10 to 50 nm by a vacuum thin film manufacturing method. The antireflection adjusting layer 14 is made of, for example, silicon nitride (SiN) and is formed by a P-CVD method. At this time, the film thickness of the antireflection adjusting layer 14 is set to, for example, 130 nm in accordance with the film thickness Tr of the portion corresponding to the photoelectric conversion portion 12r of the antireflection adjusting layer 14 described with reference to FIG. The light shielding film 15 is made of tungsten (W), for example, and is formed by a sputtering film forming method.

  Next, as shown in FIG. 3B, a resist pattern PR1 having a shape covering between the photoelectric conversion portions 12 is formed on the light shielding film 15, and the light shielding film 15 is etched using the resist pattern PR1 as a mask. After the etching is finished, the resist pattern PR1 is removed. As a result, as shown in FIG. 3C, a pattern of the light shielding film 15 having a pattern opening on the photoelectric conversion unit 12 is formed.

  Thereafter, as shown in FIG. 4A, a resist pattern PR2 is formed on the antireflection adjusting layer 14 and the light shielding film 15. The resist pattern PR2 has an opening corresponding to the photoelectric conversion unit 12b and has a shape covering the upper portions of the photoelectric conversion units 12g and 12r. The opening of the resist pattern PR2 has the same size as the opening of the light shielding film 15 corresponding to the photoelectric conversion part 12b, but may be slightly larger as long as it covers the opening of the light shielding film 15 corresponding to the photoelectric conversion parts 12g and 12r. Good.

  Subsequently, the resist pattern PR2 is used, and the antireflection adjusting layer 14 is etched using the light shielding film 15 as a mask to form a recess having a predetermined depth. At the time of etching, as shown in FIG. 4B, etching is performed so that the film thickness of the antireflection adjusting layer 14 corresponding to the photoelectric conversion portion 12b is Tb (for example, 40 nm), thereby forming the recess 14b. After the etching is completed, the resist pattern PR2 is removed. As a result, as shown in FIG. 4B, the concave portion 14 b is formed in a self-aligned manner with respect to the light shielding film 15 at a position corresponding to the photoelectric conversion portion 12 b of the antireflection adjusting layer 14.

  Next, similarly to the formation of the recess 14b, the antireflection adjustment layer 14 is etched using the resist pattern (not shown) and the light shielding film 15 as a mask, and corresponds to the photoelectric conversion portion 12g as shown in FIG. 4C. The concave portion 14g is formed by self-alignment at a position where it is to be performed. The concave portion 14g is formed so that the film thickness of the antireflection adjusting layer 14 at a portion corresponding to the photoelectric conversion portion 12g is Tg (for example, 80 nm). Further, the film thickness Tr of the antireflection adjusting layer 14 corresponding to the photoelectric conversion unit 12r is the film thickness Tr (for example, 130 nm) at the time of film formation. The relationship between the film thicknesses of the antireflection adjusting layers 14 in these portions is Tr> Tg> Tb. Thereby, as shown to C of FIG. 4, the level | step difference shape which has the recessed parts 14b and 14g in the reflection preventing adjustment layer 14 is formed.

  Subsequently, as shown in FIG. 5A, the adhesion layer 16 is formed on the antireflection adjusting layer 14 and the light shielding film 15. The adhesion layer 16 is made of, for example, an organic material such as acrylic resin, and is formed with a film thickness of 10 to 70 nm by spin coding. Note that the adhesion layer 16 may be omitted if unnecessary.

  Thereafter, as shown in FIG. 5B, the color patterns 17r, 17g, and 17b corresponding to the film thicknesses Tr, Tg, and Tb of the antireflection adjusting layer 14 are arranged on the adhesion layer 16 so as to correspond to the photoelectric conversion unit 12. Are formed in a state where the space between the light shielding films 15 is embedded. At this time, each of the color patterns 17r, 17g, and 17b is formed by lithography using a photosensitive composition containing a dye of each color.

  Next, the color patterns 17r, 17g, and 17b are flattened as necessary. As a result, the color filter 17 composed of the color patterns 17r, 17g, and 17b is formed on the adhesion layer 16 in a state where the space between the light shielding films 15 is embedded.

  After that, as shown in FIG. 2, the on-chip lens 18 is formed on the color filter 17, thereby completing the solid-state imaging device 1-1.

[Effect of the first embodiment]
In the solid-state imaging device 1-1 according to the first embodiment described above, the antireflection adjustment layer 14 having a stepped shape corresponding to the predetermined photoelectric conversion unit 12 is provided so as to cover the entire surface of the light receiving surface 11a. The structure is provided on the light receiving surface 11 a of the semiconductor substrate 11 through the protective layer 13 formed. For this reason, in the solid-state imaging device 1-1, when the antireflection adjusting layer 14 is patterned into a step shape, the patterning damage does not reach the light receiving surface 11a of the semiconductor substrate 11, and the white spot and the dark current are prevented from deteriorating. it can. Therefore, in the solid-state imaging device 1-1 provided with the antireflection adjusting layer 14, the sensitivity of each photoelectric conversion unit 12 according to the wavelength of incident light dispersed by the color filter 17 without deteriorating the white spot and dark current. Can be optimized.

  In the solid-state imaging device 1-1, the protective layer 13 has a uniform film thickness and covers the entire light receiving surface 11 a of the semiconductor substrate 11. For this reason, when the protective layer 13 functions as a pinning layer for the semiconductor substrate 11, the pinning effect for the semiconductor substrate 11 varies for each photoelectric conversion unit 12 corresponding to the wavelength of incident light dispersed by the color filter 17. White point and dark current values do not fluctuate. That is, deterioration of image quality due to color noise can be prevented. Accordingly, the antireflection condition is adjusted by the antireflection adjustment layer 14 having a step shape without fluctuation of the pinning effect, and the sensitivity of each photoelectric conversion unit 12 is optimized according to the wavelength of incident light dispersed by the color filter 17. It becomes possible to plan.

  Further, the antireflection adjusting layer 14 functions as a multilayer antireflection film on the light receiving surface 11 a of the semiconductor substrate 11 by having a refractive index different from that of the color filter 17. Further, since the antireflection adjusting layer 14 has a stepped shape corresponding to a predetermined photoelectric conversion portion, the reflectance of each color incident light dispersed by the color filter 17 at each photoelectric conversion portion 12 is minimized. Thus, the sensitivity of each photoelectric conversion unit 12 can be optimized.

  FIG. 6 is a graph showing a measurement result of the transmittance from the color filter 17 to the semiconductor substrate 11 in the solid-state imaging device 1-1 of the first embodiment. The broken line R indicates the transmittance when the thickness of the antireflection adjusting layer 14 is 130 nm, and it can be seen that the transmittance is 95% or more for light having a wavelength of about 480 to 700 nm. The solid line G indicates the transmittance when the thickness of the antireflection adjusting layer 14 is 80 nm, and it can be seen that the transmittance is 95% or more for light having a wavelength of about 460 to 620 nm. The broken line B shows the transmittance when the thickness of the antireflection adjusting layer 14 is 40 nm, and it can be seen that the transmittance is 95% or more for light having a wavelength of about 440 to 600 nm.

  Thereby, in the solid-state imaging device 1-1, when the film thicknesses Tr, Tg, and Tb of the portions of the antireflection adjusting layer 14 having the step shape are 130 nm, 80 nm, and 40 nm, respectively, red light (wavelength 630 nm) It can be seen that the transmittance for green light (wavelength 540 nm) and blue light (wavelength 460 nm) can be adjusted to 95% or more, respectively. Therefore, in the solid-state imaging device 1-1, it can be confirmed that the sensitivity of each of the photoelectric conversion units 12r, 12g, and 12b to which red light, green light, and blue light are incident can be optimized.

  In the solid-state imaging device 1-1, the color filter 17 is embedded between the light shielding films 15. For this reason, the distance between the on-chip lens 18 and the semiconductor substrate 11 is shortened, color mixing can be suppressed, and the light receiving sensitivity in the photoelectric conversion unit 12 can be improved. As a result, it is possible to provide the solid-state imaging device 1-1 in which color mixing is suppressed and color reproducibility is high.

  Further, since the antireflection adjusting layer 14 is a layer patterned using the light shielding film 15 as a mask, the antireflection adjusting layer 14 under the light shielding film 15 is not thinned and maintains the film thickness at the time of film formation. A certain distance can be ensured between the light shielding film 15 and the light receiving surface 11 a of the semiconductor substrate 11. Thereby, even when the light shielding film 15 is a floating electrode, it is possible to prevent the white spot and the dark current from deteriorating.

  In the present embodiment, the case where the film thickness Tr of the antireflection adjustment layer 14 in the part corresponding to the photoelectric conversion unit 12r is the same as the film thickness of the antireflection adjustment layer 14 in the lower part of the light shielding film 15 has been described. However, the present invention is not limited to this, and a recess may be provided in a portion corresponding to the photoelectric conversion portion 12r of the antireflection adjusting layer 14. Also in this case, the relationship between the film thicknesses Tr, Tg, and Tb of each part of the antireflection adjusting layer 14 is Tr> Tg> Tb.

  In the present embodiment, the case where the color filter 17 has a pattern of three colors of RGB has been described. However, the present invention is not limited to this, and the color filter 17 may have a pattern of two colors or four colors or more. In this case, the antireflection adjusting layer 14 has a stepped shape that is thinned in two steps or four or more steps according to the pattern of the color filter 17.

  Further, when the adhesion between the light shielding film 15 and the color filter 17 is good, the adhesion layer 16 may be omitted.

<3. Modification 1 of First Embodiment>
(Example in which the color filter is provided only in the opening of the light shielding film)
FIG. 7 is a cross-sectional view of the main part showing the configuration of Modification 1 of the solid-state imaging device of the first embodiment. As shown in FIG. 7, the solid-state imaging device 1-1a of Modification 1 is different from the solid-state imaging device 1-1 described with reference to FIG. It is only provided in the opening of the film 15. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  The solid-state imaging device 1-1a of Modification 1 is characterized in that the color filter 17 is provided only in the opening of the light shielding film 15 on the antireflection adjusting layer 14. An adhesion layer 16 is provided on the bottom and side walls in the opening of the light shielding film 15, and a color filter 17 is provided in the opening of the light shielding film 15 via the adhesion layer 16. The upper surface of the color filter 17 and the upper surface of the light shielding film 15 have the same height, and form a flat surface. An on-chip lens 18 is provided on a flat surface formed by the color filter 17 and the light shielding film 15.

[Method for Manufacturing Solid-State Imaging Device 1-1a]
The manufacturing method of the solid-state imaging device 1-1a of Modification 1 is characterized in that the color filter 17 is formed by pattern formation of each color pattern 17r, 17g, 17b using the light shielding film 15 as a mask. Form.

  First, the processes up to the step of patterning the antireflection adjusting layer 14 described above with reference to FIG. 4C into steps are formed in the same manner as the solid-state imaging device 1-1 of the first embodiment.

  Subsequently, the adhesion layer 16 is formed on the antireflection adjusting layer 14 and the light shielding film 15, and the adhesion layer 16 on the light shielding film 15 is removed by etch back. Thereby, as shown in FIG. 7, the adhesion layer 16 is formed on the bottom surface and the side wall in the opening of the light shielding film 15.

  Next, the color patterns 17r, 17g, and 17b corresponding to the film thicknesses Tr, Tg, and Tb of the antireflection adjustment layer 14 are embedded between the light shielding films 15 on the adhesion layer 16 in an arrangement corresponding to the photoelectric conversion unit 12. Form in state. At this time, for example, each of the color patterns 17r and 17g is formed by a lithography method using a photosensitive composition containing a dye of each color. Thereafter, a photosensitive composition corresponding to the pattern 17b is applied and cured. Subsequently, flattening is performed until the color patterns 17r, 17g, and 17b have the same height as the light shielding film 15. As a result, as shown in FIG. 7, the color patterns 17 r, 17 g, and 17 b are formed in a self-aligned manner with respect to the light shielding film 15, and the color filter 17 is formed only in the opening of the light shielding film 15.

  Thereafter, as shown in FIG. 7, an on-chip lens 18 is formed on the color filter 17 and the light shielding film 15, thereby completing the solid-state imaging device 1-1a.

[Effect of Modification 1]
Also in the solid-state imaging device 1-1a of the modified example 1 described above, the same effect as that of the first embodiment can be obtained.

  Further, in the solid-state imaging device 1-1a, the antireflection adjusting layer 14 is self-aligned into a stepped shape having recesses 14g and 14b corresponding to the predetermined photoelectric conversion units 12g and 12b by patterning using the light shielding film 15 as a mask. Formed with. Further, the color patterns 17r, 17g, and 17b constituting the color filter 17 are formed on the light shielding film 15 by self-alignment. Therefore, both the antireflection adjusting layer 14 and the color filter 17 are formed in a self-aligned manner with respect to the light shielding film 15, and therefore there is no misalignment between the antireflection adjusting layer 14 and the color filter 17. Thereby, the solid-state imaging device 1-1a with higher accuracy can be provided.

<4. Modification 2 of First Embodiment>
(Example in which the antireflection adjusting layer has a stepped shape in which the film thickness is reduced to two levels)
FIG. 8 is a cross-sectional view of the main part showing the configuration of Modification 2 of the solid-state imaging device of the first embodiment. As shown in FIG. 8, the solid-state imaging device 1-1 b of Modification 2 is different from the solid-state imaging device 1-1 described with reference to FIG. 2 in that the antireflection adjustment layer 14 is a predetermined photoelectric conversion unit 12. Corresponding to this, it has a stepped shape that has been thinned to a two-stage film thickness. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  The solid-state imaging device 1-1b of Modification 2 is characterized in that the antireflection adjustment layer 14 has a stepped shape that is thinned into two stages of film thickness with respect to the color filter 17 having RGB color patterns. is there. For example, when the color filter 17 has the RGB color patterns 17r, 17g, and 17b, the film thicknesses of the antireflection adjusting layer 14 corresponding to the photoelectric conversion units 12r, 12g, and 12b are Tr, Tg, and Tb, respectively. is there. These film thicknesses Tr, Tg, and Tb are not different from each other but differ in two stages. For example, as shown in FIG. 8, the relationship Tr> Tg = Tb is satisfied. In this case, for example, the film thickness Tr is 130 nm, and the film thicknesses Tg and Tb are 40 nm. Further, the relationship Tr = Tg> Tb may be used. In this case, for example, the film thicknesses Tr and Tg are set to 130 nm, and the film thickness Tb is set to 40 nm.

[Effect of Modification 2]
Also in the solid-state imaging device 1-1b of the modified example 2 described above, the same effect as in the first embodiment can be obtained.

  Furthermore, the solid-state imaging device 1-1b of Modification 2 is configured to have a step shape in which the antireflection adjustment layer 14 is thinned to a two-stage film thickness with respect to the color filter 17 having a three-color pattern. . For this reason, when patterning the antireflection adjusting layer 14 into a stepped shape, the resist pattern and the number of steps used are reduced. Therefore, the solid-state imaging device 1-1b with high manufacturing efficiency can be provided.

  In addition, although the case where the color filter 17 has each color pattern of RGB was demonstrated in the modification 2, it is not restricted to this, The color filter 17 may have a pattern of 4 colors or more. For example, when the color filter 17 has a pattern of four colors, the antireflection adjustment layer 14 has a stepped shape that is thinned in two or three stages of film thickness.

<5. Solid-State Imaging Device of Second Embodiment>
(Example in which the antireflection adjusting layer is provided in the upper layer of the light shielding film: Part 1)
FIG. 9 is a cross-sectional view of the main part showing the configuration of the solid-state imaging device of the second embodiment. The characteristic configuration of the solid-state imaging device 1-2 according to the second embodiment will be described below based on this drawing. Note that, in the second embodiment and its modifications, the same reference numerals are given to the same components as those in the first embodiment, and duplicate descriptions are omitted.

  The solid-state imaging device 1-2 shown in FIG. 9 is different from the solid-state imaging device 1-1 of the first embodiment described with reference to FIG. It is in the upper layer. The antireflection adjusting layer 24 has a stepped shape by etching using the light shielding film 15 as a mask. Other configurations are the same as those of the first embodiment. However, in the solid-state imaging device 1-2, the color filter 17 is directly provided on the antireflection adjusting layer 24 and the light shielding film 15 without the adhesion layer without providing the adhesion layer. An adhesion layer may be provided.

  In the solid-state imaging device 1-2, the light shielding film 15 is patterned on the protective layer 13, and the antireflection adjusting layer 24 (24 r, 24 g, 24 b) is provided between the light shielding films 15.

  The antireflection adjusting layer 24 has a step shape composed of the antireflection adjusting layers 24r, 24g, and 24b thinned corresponding to the photoelectric conversion units 12r, 12g, and 12b. The film thicknesses of these antireflection adjusting layers 24r, 24g, and 24b are Tr, Tg, and Tb, respectively, and the relationship Tr> Tg> Tb is established as in the first embodiment.

  The antireflection adjusting layer 24 is a layer etched using the light shielding film 15 as a mask. Of the antireflection adjusting layers 24r, 24g, and 24b, at least the antireflection adjusting layers 24g and 24b are etched portions using the light shielding film 15 as a mask. Therefore, the film thicknesses Tg and Tb of the antireflection adjusting layers 24g and 24b are equal to or less than the film thickness of the light shielding film 15, and the antireflection adjusting layers 24g and 24b are provided only in the openings of the light shielding film 15.

  On the other hand, the antireflection adjusting layer 24r may be a portion etched using the light shielding film 15 as a mask. In this case, the antireflection adjusting layer 24r is provided only in the opening of the light shielding film 15, similarly to the antireflection adjusting layers 24g and 24b. Further, as shown in the drawing, the antireflection adjusting layer 24r may be a portion that is not thinned and maintains the film thickness at the time of film formation. In this case, the antireflection adjusting layer 24r is provided by embedding the light shielding film 15, that is, it is provided so as to embed the opening of the light shielding film 15 and cover the light shielding film 15.

  The material described in the first embodiment is used for such an antireflection adjusting layer 24.

[Method for Manufacturing Solid-State Imaging Device 1-2]
10 and 11 are cross-sectional process diagrams for explaining a method of manufacturing the solid-state imaging device 1-2 according to the second embodiment. Hereinafter, a method for manufacturing the solid-state imaging device 1-2 will be described based on these drawings.

  First, as illustrated in FIG. 10A, a semiconductor substrate 11 having a plurality of photoelectric conversion units 12 is prepared in the same manner as the method for manufacturing the solid-state imaging device 1-1 of the first embodiment. 11 is formed on the side opposite to the light receiving surface 11a. Next, the protective layer 13 is formed on the light receiving surface 11 a of the semiconductor substrate 11, and the light shielding film 15 is patterned on the protective layer 13.

  Subsequently, as shown in FIG. 10B, an antireflection adjusting layer 24 is formed on the protective layer 13 so as to cover the light shielding film 15. At this time, the antireflection adjusting layer 24 is formed with a film thickness similar to the film thickness Tr of the portion corresponding to the photoelectric conversion portion 12r of the antireflection adjusting layer 24 described above with reference to FIG.

  Next, as shown in FIG. 10C, a resist pattern PR <b> 3 is formed on the antireflection adjusting layer 24. The resist pattern PR3 has an opening corresponding to the photoelectric conversion unit 12b and has a shape that covers the upper portions of the photoelectric conversion units 12g and 12r. The opening of the resist pattern PR3 has the same size as the opening of the light shielding film 15 corresponding to the photoelectric conversion portion 12b, but may be slightly larger as long as it covers the opening of the light shielding film 15 corresponding to the photoelectric conversion portions 12g and 12r. Good.

  Next, the resist pattern PR3 is used, and the antireflection adjusting layer 24 is etched using the light shielding film 15 as a mask. As shown in FIG. 11A, the film thickness is Tb corresponding to the photoelectric conversion portion 12b. A certain antireflection adjusting layer 24 b is formed on the light shielding film 15 by self-alignment. After the etching is completed, the resist pattern PR3 is removed. As a result, an antireflection adjusting layer 24b having a film thickness Tb is formed in the opening of the light shielding film 15 corresponding to the photoelectric conversion unit 12b.

  Subsequently, similarly to the formation of the antireflection adjusting layer 24b, the antireflection adjusting layer 24 is etched using the light shielding film 15 as a mask, and as shown in FIG. 11B, the light shielding film 15 corresponding to the photoelectric conversion unit 12g is formed. An antireflection adjusting layer 24g having a film thickness Tg is formed in the opening in a self-aligned manner with respect to the light shielding film 15. The remaining portion of the antireflection adjustment layer 24 that is not etched becomes the antireflection adjustment layer 24r having a film thickness of Tr corresponding to the photoelectric conversion portion 12r. The relationship between the film thicknesses Tr, Tg, and Tb of these antireflection adjusting layers 24r, 24g, and 24b is Tr> Tg> Tb. As a result, a step-shaped antireflection adjustment layer 24 composed of the antireflection adjustment layers 24r, 24g, and 24b is formed.

  Thereafter, as shown in FIG. 10, each color pattern 17r corresponding to the film thicknesses Tr, Tg, Tb of the antireflection adjusting layer 14 is arranged on the antireflection adjusting layer 24 in correspondence with the photoelectric conversion units 12r, 12g, 12b. , 17g, and 17b are formed in a state where the light shielding film 15 is embedded. Next, the on-chip lens 18 is formed on the color filter 17, thereby completing the solid-state imaging device 1-2.

[Effect of the second embodiment]
In the solid-state imaging device 1-2 of the second embodiment described above, the same effect as that of the first embodiment can be obtained. That is, in the solid-state imaging device 1-2, the antireflection adjustment layer 24 having a stepped shape corresponding to the predetermined photoelectric conversion unit 12 is provided with the protective layer 13 provided so as to cover the entire surface of the light receiving surface 11a. In this configuration, the light receiving surface 11 a of the semiconductor substrate 11 is provided. For this reason, in the solid-state imaging device 1-2, when the antireflection adjusting layer 24 is patterned into a stepped shape, the patterning damage does not reach the light receiving surface 11a of the semiconductor substrate 11, and white spots and dark current are prevented from deteriorating. it can. Therefore, in the solid-state imaging device 1-2 provided with the antireflection adjusting layer 24, the sensitivity of each photoelectric conversion unit 12 according to the wavelength of incident light dispersed by the color filter 17 without deteriorating the white spot and dark current. Can be optimized.

  In the solid-state imaging device 1-2, as in the first embodiment, the protective layer 13 has a uniform film thickness and covers the entire light receiving surface 11a of the semiconductor substrate 11. For this reason, when the protective layer 13 functions as a pinning layer for the semiconductor substrate 11, the antireflection condition is adjusted by the antireflection adjusting layer 24 having a step shape and the spectrum is dispersed by the color filter 17 without fluctuation of the pinning effect. The sensitivity of each photoelectric conversion unit 12 can be optimized according to the wavelength of incident light.

  The antireflection adjusting layer 24 functions as a multilayer antireflection film on the light receiving surface 11a of the semiconductor substrate 11 by having a refractive index different from that of the color filter 17 as in the first embodiment. Further, since the antireflection adjusting layer 24 has a stepped shape corresponding to a predetermined photoelectric conversion unit, the reflectance of each color incident light dispersed by the color filter 17 at each photoelectric conversion unit 12 is minimized. Thus, the sensitivity of each photoelectric conversion unit 12 can be optimized.

  In the solid-state imaging device 1-2, the color filter 17 is embedded between the light shielding films 15 as in the first embodiment. For this reason, the distance between the on-chip lens 18 and the semiconductor substrate 11 is shortened, color mixing can be suppressed, and the light receiving sensitivity in the photoelectric conversion unit 12 can be improved. As a result, it is possible to provide a solid-state imaging device 1-2 in which color mixing is suppressed and color reproducibility is high.

  In addition, you may combine the modification 2 (refer FIG. 8) of 1st Embodiment demonstrated previously with the solid-state imaging device 1-2 of this embodiment. In this case, with respect to the color filter 17 having a three-color pattern, the antireflection adjustment layer 24 has a stepped shape that is thinned to a two-stage film thickness corresponding to the predetermined photoelectric conversion unit 12. The film thicknesses Tr, Tg, and Tb of the antireflection adjusting layers 24r, 24g, and 24b are adjusted to satisfy the relationship of Tr> Tg = Tb or Tr = Tg> Tb.

  Further, the color filter 17 may be provided on the antireflection adjusting layer 24 and the light shielding film 15 through an adhesion layer.

<6. Modification 1 of Second Embodiment>
(Example in which the antireflection adjusting layer has a laminated structure provided in the upper and lower layers of the light shielding film)
FIG. 12 is a cross-sectional view of the main part showing the configuration of Modification 1 of the solid-state imaging device of the second embodiment. As shown in FIG. 12, the solid-state imaging device 1-2 a of Modification 1 is different from the solid-state imaging device 1-2 described with reference to FIG. 10 in that the antireflection adjustment layer 24 blocks light on the protective layer 13. This is a laminated structure provided in the upper layer and the lower layer of the film 15. That is, it is a laminated structure including an antireflection adjustment layer 24-1 provided in the lower layer of the light shielding film 15 and an antireflection adjustment layer 24-2 provided in the upper layer of the light shielding film 15. In addition, the same code | symbol is attached | subjected to the same component as 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  The solid-state imaging device 1-2a of Modification 1 is a layer for further antireflection adjustment between the protective layer 13 and the antireflection adjustment layer 24 having a step shape in the solid-state imaging device 1-2 shown in FIG. It is the structure which added. As shown in FIG. 12, the solid-state imaging device 1-2a of Modification 1 has an antireflection adjustment layer 24-1 provided in the lower layer of the light shielding film 15 and a reflection provided in the upper layer of the light shielding film 15. It has the antireflection adjustment layer 24 of the laminated structure comprised with the prevention adjustment layer 24-2. At least the upper antireflection adjusting layer 24-2 of the laminated structure has a stepped shape by etching using the light shielding film 15 as a mask. That is, the lower antireflection adjustment layer 24-1 is formed on the protective layer 13, the light shielding film 15 is patterned thereon, and the upper antireflection adjustment layer 24-2 is stepped between the light shielding films 15. It is provided in the shape.

  In the antireflection adjusting layer 24 having such a laminated structure, the film thicknesses of the portions corresponding to the photoelectric conversion units 12r, 12g, and 12b are Tr, Tg, and Tb. The relationship is> Tg> Tb. Each of the film thicknesses Tr, Tg, and Tb is a thickness obtained by combining the lower antireflection adjustment layer 24-1 and the upper antireflection adjustment layer 24-2.

[Antireflection adjusting layers 24-1 and 24-2]
The antireflection adjusting layers 24-1 and 24-2 may be layers made of the same material, or may be layers made of different materials. When the layers are made of different materials, the difference in refractive index between the antireflection adjusting layers 24-1 and 24-2 is preferably within 0.1. The materials described in the first embodiment are used for the antireflection adjusting layers 24-1 and 24-2.

[Effect of Modification 1]
Also in the solid-state imaging device 1-2a of the modified example 1 described above, the same effect as in the second embodiment can be obtained.

  Not only the upper antireflection adjustment layer 24-2 has a step shape, but also the lower antireflection adjustment layer 24-1 may have a step shape. In this case, first, the lower antireflection adjustment layer 24-1 and the upper antireflection adjustment layer 24-2 are stacked, and then the upper antireflection adjustment layer 24-2 is etched, followed by the lower antireflection adjustment layer 24-2. Layer 24-1 may be etched. Alternatively, the lower antireflection adjustment layer 24-1 may be etched first, and then the upper antireflection adjustment layer 24-2 may be formed and etched.

  Moreover, the antireflection adjusting layer 24 is not limited to two layers, and may be a laminated structure including a plurality of layers of three or more layers. In this case, at least the uppermost layer has a step shape.

<7. Solid-State Imaging Device of Third Embodiment>
(Example in which the antireflection adjusting layer is provided on the upper layer of the light shielding film: Part 2)
FIG. 13 is a cross-sectional view of the main part showing the configuration of the solid-state imaging device of the third embodiment. The characteristic configuration of the solid-state imaging device 1-3 according to the third embodiment will be described below based on this drawing. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The solid-state imaging device 1-3 illustrated in FIG. 13 is different from the solid-state imaging device 1-1 according to the first embodiment described with reference to FIG. It is in the upper layer. Other configurations are the same as those of the first embodiment. However, in the solid-state imaging device 1-3, the color filter 17 is directly provided on the antireflection adjustment layer 34 without using the adhesion layer without providing the adhesion layer. The color filter 17 is provided on the antireflection adjusting layer 34 without being embedded between the light shielding films 15. An adhesion layer may be provided.

  In the solid-state imaging device 1-3, the light shielding film 15 is patterned on the protective layer 13, and the antireflection adjusting layer 34 is provided by embedding the light shielding film 15.

  The antireflection adjusting layer 34 has a stepped shape that is thinned corresponding to each of the photoelectric conversion units 12r, 12g, and 12b. The film thicknesses of the portions corresponding to the photoelectric conversion units 12r, 12g, and 12b of the antireflection adjusting layer 34 are Tr, Tg, and Tb, and the relationship Tr> Tg> Tb is satisfied as in the first embodiment. It has become.

[Effect of the third embodiment]
Also in the solid-state imaging device 1-3 of the third embodiment described above, the same effect as that of the first embodiment can be obtained. That is, in the solid-state imaging device 1-3, the antireflection adjustment layer 34 having a stepped shape corresponding to the predetermined photoelectric conversion unit 12 is provided with the protective layer 13 provided so as to cover the entire surface of the light receiving surface 11a. In this configuration, the light receiving surface 11 a of the semiconductor substrate 11 is provided. For this reason, in the solid-state imaging device 1-3, when the antireflection adjustment layer 34 is patterned into a stepped shape, the patterning damage does not reach the light receiving surface 11a of the semiconductor substrate 11, and white spots and dark current are prevented from deteriorating. it can. Therefore, in the solid-state imaging device 1-3 including the antireflection adjusting layer 34, the sensitivity of each photoelectric conversion unit 12 is determined according to the wavelength of incident light dispersed by the color filter 17 without deteriorating white spots and dark current. Can be optimized.

  Further, in the solid-state imaging device 1-3, as in the first embodiment, the protective layer 13 has a uniform film thickness and covers the entire light receiving surface 11a of the semiconductor substrate 11. As a result, when the protective layer 13 functions as a pinning layer for the semiconductor substrate 11, the antireflection condition is adjusted by the antireflection adjustment layer 34 having a step shape and the spectrum is dispersed by the color filter 17 without fluctuation of the pinning effect. The sensitivity of each photoelectric conversion unit 12 can be optimized according to the wavelength of incident light.

  Further, the antireflection adjusting layer 34 has a refractive index different from that of the color filter 17, thereby functioning as a multilayer antireflection film on the light receiving surface 11 a of the semiconductor substrate 11. Further, since the antireflection adjusting layer 34 has a stepped shape corresponding to a predetermined photoelectric conversion unit, the reflectance of each color incident light separated by the color filter 17 at each photoelectric conversion unit 12 is minimized. Thus, the sensitivity of each photoelectric conversion unit 12 can be optimized.

  In addition, you may combine the modification 2 (refer FIG. 8) of 1st Embodiment demonstrated previously with the solid-state imaging device 1-3 of this embodiment. In this case, with respect to the color filter 17 having a three-color pattern, the antireflection adjustment layer 34 has a stepped shape that is thinned in two steps corresponding to the predetermined photoelectric conversion unit 12. The film thicknesses Tr, Tg, and Tb of the respective portions of the antireflection adjusting layer 34 are adjusted so as to satisfy the relationship Tr> Tg = Tb or Tr = Tg> Tb.

  Moreover, you may combine the modification 1 (refer FIG. 12) of 2nd Embodiment demonstrated previously with the solid-state imaging device 1-3 of this embodiment. In this case, the antireflection adjusting layer 34 has a laminated structure provided in the upper layer and the lower layer of the light shielding film 15, and at least the upper layer has a step shape.

<8. Fourth Embodiment>
(Example of electronic equipment using solid-state imaging device)
The solid-state imaging device according to the present technology described in the above embodiment is applied to an electronic device such as a camera system such as a digital camera or a video camera, a mobile phone having an imaging function, or another device having an imaging function. Can be applied.

  FIG. 14 is a configuration diagram of a camera using a solid-state imaging device as an example of an electronic apparatus according to the present technology. The camera according to the present embodiment is an example of a video camera capable of capturing still images or moving images. The camera 91 includes a solid-state imaging device 1, an optical system 93 that guides incident light to a light receiving sensor unit of the solid-state imaging device 1, a shutter device 94, a drive circuit 95 that drives the solid-state imaging device 1, and the solid-state imaging device 1. And a signal processing circuit 96 for processing the output signal.

  As the solid-state imaging device 1, the solid-state imaging device having the configuration described in each of the above-described embodiments is applied. The optical system (optical lens) 93 forms image light (incident light) from the subject on the imaging surface of the solid-state imaging device 1. Thereby, signal charges are accumulated in the solid-state imaging device 1 for a certain period. Such an optical system 93 may be an optical lens system including a plurality of optical lenses. The shutter device 94 controls the light irradiation period and the light shielding period to the solid-state imaging device 1. The drive circuit 95 supplies drive signals to the solid-state imaging device 1 and the shutter device 94, and controls the signal output operation to the signal processing circuit 96 of the solid-state imaging device 1 and the shutter device by the supplied drive signal (timing signal). 94 shutter operation is controlled. That is, the drive circuit 95 performs a signal transfer operation from the solid-state imaging device 1 to the signal processing circuit 96 by supplying a drive signal (timing signal). The signal processing circuit 96 performs various signal processing on the signal transferred from the solid-state imaging device 1. The video signal subjected to the signal processing is stored in a storage medium such as a memory or output to a monitor.

  According to the electronic apparatus according to the present embodiment described above, an electronic device having an imaging function can be obtained by using any one of the solid-state imaging devices having good light receiving characteristics described in the first to third embodiments. It becomes possible to achieve high-definition imaging and downsizing of the device.

  In addition, this technique can also take the following structures.

(1)
A semiconductor substrate having a plurality of photoelectric conversion parts;
A protective layer provided directly over the light receiving surface of the semiconductor substrate and covering the entire surface of the light receiving surface;
A light-shielding film that is provided on the protective layer and shields light between the photoelectric conversion units;
An antireflection adjusting layer provided on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and having a stepped shape corresponding to the predetermined photoelectric conversion unit;
A color filter provided on the antireflection adjustment layer in an arrangement corresponding to the photoelectric conversion unit, and having each color pattern corresponding to the film thickness of the antireflection adjustment layer;
A solid-state imaging device comprising: a wiring layer provided on a side opposite to the light receiving surface of the semiconductor substrate.

(2)
The antireflection adjusting layer is provided on a lower layer of the light shielding film on the protective layer, and has a stepped shape by etching using the light shielding film as a mask.
The solid-state imaging device according to (1), wherein the color filter is provided with the space between the light shielding films embedded on the antireflection adjustment layer.

(3)
The solid-state imaging device according to (2), wherein the color filter is provided only in the opening of the light shielding film on the antireflection adjustment layer.

(4)
The solid-state imaging device according to (2) or (3), wherein the antireflection adjustment layer has an equal thickness in a lower portion of the light shielding film.

(5)
The solid-state imaging device according to (1), wherein the antireflection adjustment layer is provided on the light shielding film on the protective layer.

(6)
The antireflection adjusting layer has a stepped shape by etching using the light shielding film as a mask,
The solid-state imaging device according to (5), wherein the color filter is provided with the space between the light shielding films embedded on the antireflection adjustment layer.

(7)
The antireflection adjusting layer has a laminated structure provided on the protective layer in an upper layer and a lower layer of the light shielding film, and at least the uppermost layer constituting the laminated structure has the step shape. apparatus.

(8)
The uppermost layer has a stepped shape by etching using the light shielding film as a mask,
The solid-state imaging device according to (7), wherein the color filter is provided on the antireflection adjustment layer with a space between the light shielding films embedded therein.

(9)
The solid-state imaging device according to any one of (1) to (8), wherein the protective layer has a uniform film thickness.

(10)
The solid-state imaging device according to any one of (1) to (9), wherein a refractive index of the antireflection adjusting layer is smaller than a refractive index of the color filter.

(11)
The solid-state imaging according to any one of (1) to (10), wherein the antireflection adjustment layer has a larger thickness of a portion corresponding to the photoelectric conversion unit as a wavelength of light incident on the corresponding photoelectric conversion unit is larger. apparatus.

(12)
The solid-state imaging device according to any one of (1) to (11), wherein the color filter has a flattened surface.

(13)
Forming a protective layer covering the entire surface of the light receiving surface directly on the light receiving surface of the semiconductor substrate having a plurality of photoelectric conversion parts;
Forming a light shielding film that shields light between the photoelectric conversion portions on the protective layer;
Forming an antireflection adjusting layer on at least one of an upper layer and a lower layer of the light shielding film on the protective layer;
Patterning the antireflection adjusting layer into a stepped shape thinned corresponding to the predetermined photoelectric conversion part;
Forming a color filter having each color pattern corresponding to the film thickness of the antireflection adjusting layer in an arrangement corresponding to the photoelectric conversion portion on the antireflection adjusting layer;
Forming a wiring layer on a side opposite to the light receiving surface of the semiconductor substrate;

(14)
When forming the antireflection adjustment layer, the antireflection adjustment layer is formed under the light shielding film on the protective layer,
When forming the light shielding film, the light shielding film is formed on the antireflection adjusting layer formed on the protective layer,
When patterning the antireflection adjusting layer, patterning using the light shielding film as a mask,
The method for manufacturing a solid-state imaging device according to (13), wherein when forming the color filter, the color filter is formed by embedding a space between the light shielding films on the antireflection adjusting layer.

(15)
When forming the color filter, each color pattern is patterned using the light shielding film as a mask, and the color filter is formed only in the opening of the light shielding film on the antireflection adjustment layer. Manufacturing method of imaging apparatus.

(16)
The method for manufacturing a solid-state imaging device according to (13), wherein, when forming the antireflection adjustment layer, after forming the light shielding film, the antireflection adjustment layer is formed on the light shielding film on the protective layer.

(17)
When patterning the antireflection adjusting layer, using a resist pattern and patterning with the light shielding film as a mask,
The method for manufacturing a solid-state imaging device according to (16), wherein when forming the color filter, the color filter is formed by embedding a space between the light shielding films on the antireflection adjusting layer.

(18)
A semiconductor substrate having a plurality of photoelectric conversion parts;
A protective layer provided directly over the light receiving surface of the semiconductor substrate and covering the entire surface of the light receiving surface;
A light-shielding film that is provided on the protective layer and shields light between the photoelectric conversion units;
An antireflection adjusting layer provided on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and having a stepped shape corresponding to the predetermined photoelectric conversion unit;
A color filter provided on the antireflection adjustment layer in an arrangement corresponding to the photoelectric conversion unit, and having each color pattern corresponding to the film thickness of the antireflection adjustment layer;
A wiring layer provided on the opposite side of the light receiving surface of the semiconductor substrate;
An electronic apparatus comprising: an optical system that guides incident light to the photoelectric conversion unit.

  DESCRIPTION OF SYMBOLS 1,1-1, 1-1a, 1-1b, 1-2, 1-2a, 1-3 ... Solid-state imaging device, 11 ... Semiconductor substrate, 11a ... Light-receiving surface, 12, 12r, 12g, 12b ... Photoelectric conversion 13, protective layer, 14, 24, 24 r, 24 g, 24 b, 24-1, 24-2, 34 ... antireflection adjusting layer, 15 ... light shielding film, 17 ... color filter, 19 ... wiring layer

Claims (18)

A semiconductor substrate having a plurality of photoelectric conversion parts;
A protective layer provided directly over the light receiving surface of the semiconductor substrate and covering the entire surface of the light receiving surface;
A light-shielding film that is provided on the protective layer and shields light between the photoelectric conversion units;
An antireflection adjusting layer provided on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and having a stepped shape corresponding to the predetermined photoelectric conversion unit;
A color filter provided on the antireflection adjustment layer in an arrangement corresponding to the photoelectric conversion unit, and having each color pattern corresponding to the film thickness of the antireflection adjustment layer;
A solid-state imaging device comprising: a wiring layer provided on a side opposite to the light receiving surface of the semiconductor substrate. The antireflection adjusting layer is provided on a lower layer of the light shielding film on the protective layer, and has a stepped shape by etching using the light shielding film as a mask.
The solid-state imaging device according to claim 1, wherein the color filter is provided by embedding a space between the light shielding films on the antireflection adjustment layer. The solid-state imaging device according to claim 2, wherein the color filter is provided only in the opening of the light shielding film on the antireflection adjustment layer. The solid-state imaging device according to claim 2, wherein the antireflection adjustment layer has an equal thickness in a lower portion of the light shielding film. The solid-state imaging device according to claim 1, wherein the antireflection adjusting layer is provided in an upper layer of the light shielding film on the protective layer. The antireflection adjusting layer has a stepped shape by etching using the light shielding film as a mask,
The solid-state imaging device according to claim 5, wherein the color filter is provided by embedding a space between the light shielding films on the antireflection adjustment layer. 2. The solid-state imaging device according to claim 1, wherein the antireflection adjusting layer has a stacked structure provided on an upper layer and a lower layer of the light shielding film on the protective layer, and at least an upper layer constituting the stacked structure has the step shape. . The upper layer has a stepped shape by etching using the light shielding film as a mask,
The solid-state imaging device according to claim 7, wherein the color filter is provided by embedding a space between the light shielding films on the antireflection adjustment layer. The solid-state imaging device according to claim 1, wherein the protective layer has a uniform film thickness. The solid-state imaging device according to claim 1, wherein a refractive index of the antireflection adjusting layer is smaller than a refractive index of the color filter. The solid-state imaging device according to claim 1, wherein the antireflection adjustment layer has a larger film thickness in a portion corresponding to the photoelectric conversion unit as a wavelength of light incident on the corresponding photoelectric conversion unit is larger. The solid-state imaging device according to claim 1, wherein the color filter has a flattened surface. Forming a protective layer covering the entire surface of the light receiving surface directly on the light receiving surface of the semiconductor substrate having a plurality of photoelectric conversion parts;
Forming a light shielding film that shields light between the photoelectric conversion portions on the protective layer;
Forming an antireflection adjusting layer on at least one of an upper layer and a lower layer of the light shielding film on the protective layer;
Patterning the antireflection adjusting layer into a stepped shape thinned corresponding to the predetermined photoelectric conversion part;
Forming a color filter having each color pattern corresponding to the film thickness of the antireflection adjusting layer in an arrangement corresponding to the photoelectric conversion portion on the antireflection adjusting layer;
Forming a wiring layer on a side opposite to the light receiving surface of the semiconductor substrate; When forming the antireflection adjustment layer, the antireflection adjustment layer is formed under the light shielding film on the protective layer,
When forming the light shielding film, the light shielding film is formed on the antireflection adjusting layer formed on the protective layer,
When patterning the antireflection adjusting layer, patterning using the light shielding film as a mask,
The method for manufacturing a solid-state imaging device according to claim 13, wherein when forming the color filter, the color filter is formed by embedding a space between the light shielding films on the antireflection adjusting layer. The solid filter according to claim 14, wherein when forming the color filter, each color pattern is patterned using the light shielding film as a mask, and the color filter is formed only in the opening of the light shielding film on the antireflection adjusting layer. Manufacturing method of imaging apparatus. The method for manufacturing a solid-state imaging device according to claim 13, wherein when forming the antireflection adjustment layer, after forming the light shielding film, the antireflection adjustment layer is formed on the protective layer and on the light shielding film. When patterning the antireflection adjusting layer, using a resist pattern and patterning with the light shielding film as a mask,
The method of manufacturing a solid-state imaging device according to claim 16, wherein when forming the color filter, the color filter is formed by embedding a space between the light shielding films on the antireflection adjustment layer. A semiconductor substrate having a plurality of photoelectric conversion parts;
A protective layer provided directly over the light receiving surface of the semiconductor substrate and covering the entire surface of the light receiving surface;
A light-shielding film that is provided on the protective layer and shields light between the photoelectric conversion units;
An antireflection adjusting layer provided on at least one of the upper layer and the lower layer of the light shielding film on the protective layer, and having a stepped shape corresponding to the predetermined photoelectric conversion unit;
A color filter provided on the antireflection adjustment layer in an arrangement corresponding to the photoelectric conversion unit, and having each color pattern corresponding to the film thickness of the antireflection adjustment layer;
A wiring layer provided on the opposite side of the light receiving surface of the semiconductor substrate;
An electronic apparatus comprising: an optical system that guides incident light to the photoelectric conversion unit.

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