JP2007305683A - Solid state image sensing element and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid state image sensing element that is rather resistive to influence of displacement of a micro-lens or an intra-layer lens, and does not cause deterioration in fluctuation of sensitivity and smear. <P>SOLUTION: The method for manufacturing a solid state image sensing element comprises the steps of forming a photoelectric converting unit on the front surface of a semiconductor substrate, and forming an optical system on the photoelectric converting unit. Moreover, the step of forming the optical system further includes the steps of forming a film of an optical system material on the front surface of substrate on which the photoelectric converting unit and a circuit connected to the photoelectric converting unit are formed, and patterning the optical system material by conducting exposure from the rear surface side of the semiconductor substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device manufacturing method and a solid-state imaging device, and more particularly to patterning of an optical system of a solid-state imaging device.

  A solid-state imaging device using a CCD used for an area sensor or the like includes a photoelectric conversion unit including a photodiode and a charge transfer unit including a charge transfer electrode for transferring a signal charge from the photoelectric conversion unit. . A plurality of charge transfer electrodes are arranged adjacent to each other on a charge transfer path formed on the semiconductor substrate, and are sequentially driven.

  In recent years, with the miniaturization of cameras, demands for higher resolution and higher sensitivity are increasing in solid-state imaging devices, and the number of imaging pixels is increasing to more than gigapixels.

  In order to improve the sensitivity, various structures have been proposed in which a microlens is provided on the pixel surface to increase the light collection efficiency to the photodiode.

  For example, as shown in FIG. 15, an intra-layer lens 20 that also serves as a passivation film is formed on the planarizing layer 10 immediately above the photodiode unit 30 constituting the photoelectric conversion unit, and further planarized on the upper layer. A structure in which a film (translucent film 22), a color filter 50, a planarization film 61, and an on-chip lens 60 are sequentially formed has been proposed (the charge transfer unit 40 and the photodiode unit 30 will be described later in an embodiment). To do). Usually, an optical system such as a microlens or an in-layer lens is formed by patterning by forming a photoelectric conversion part and then aligning the photoelectric conversion part by photolithography. When slightly deviating from the above, the light to be collected is reflected, and the light may not be collected sufficiently.

  That is, there is a problem that a slight misalignment for patterning by photolithography causes a converging position to change due to a misalignment of the microlens or the in-layer lens, resulting in variations in sensitivity due to vignetting and a decrease. Further, the positional deviation of the light shielding film with respect to the opening of the photoelectric conversion part causes smear deterioration. Smear is a phenomenon in which when solid light is applied to a solid-state image sensor, light reaches the charge transfer section and charges are generated there. As a result, a band-shaped imaging defect appears on the screen. It is an important issue to cover the transfer part with a light shielding film and to firmly open the opening of the photoelectric conversion part.

  Accordingly, an object is to provide a solid-state imaging device with less smear and sensitivity variation, and a side wall of the charge transfer electrode is provided as a first light-shielding film, and the second and A configuration for forming a third light-shielding film has been proposed (Patent Document 1).

  In this method, the light shielding film on the electrode sidewall is formed by self-alignment, so there is no sensitivity variation or smear deterioration due to misalignment, but the sensitivity due to vignetting is affected by the misalignment of the microlens, in-layer lens, or optical waveguide. There was a problem that variations and reductions were likely to occur, and it was difficult to obtain stable sensitivity.

  An exposure method using a laser drawing method has also been proposed in order to improve pattern accuracy (Patent Document 2).

JP-A-6-260629 JP 2003-7599 A

As described above, in the conventional solid-state imaging device shown in FIG. 15, sensitivity variations and smear deterioration may occur due to a slight positional shift of the inner lens 20 that should originally be at the position indicated by the broken line. Although details will be described in detail in the embodiment, the same parts are denoted by the same reference numerals.
In addition, the technique disclosed in Patent Document 1 does not cause smear deterioration, but when forming a microlens or an in-layer lens, it is necessary to use photolithography, which is easily affected by misalignment. There was a problem.
Also, the method of Patent Document 2 can improve the pattern accuracy, but it cannot avoid displacement.
The present invention has been made in view of the above-described circumstances, and is solid-state imaging that is not easily affected by a positional shift of an optical system such as a microlens, an in-layer lens, or an optical waveguide, and that does not cause sensitivity variations and smear deterioration. An object is to provide an element.

  Therefore, the present invention is a method of manufacturing a solid-state imaging device including a step of forming a photoelectric conversion unit on a surface of a semiconductor substrate and a step of forming an optical system on the photoelectric conversion unit, wherein the optical system is formed. The step includes forming an optical material on the surface of the substrate on which the photoelectric conversion unit and the circuit unit connected to the photoelectric conversion unit are formed, and performing exposure from the back surface side of the semiconductor substrate, whereby the optical Patterning the system material.

  According to this configuration, patterning of an optical system such as a microlens, an in-layer lens, or an optical waveguide is performed in a self-aligned pattern with respect to a light shielding portion such as a light shielding film covering the charge transfer portion by exposure from the back surface. Therefore, there is no position shift, and variations in sensitivity and deterioration of smear can be prevented. In addition, it is possible to provide a solid-state imaging device that has improved light condensing performance, is not affected by the positional deviation of the optical waveguide, the microlens, and the in-layer lens, and does not vary in sensitivity due to vignetting.

  The present invention also includes a step of forming, as the circuit unit, a charge transfer unit including a charge transfer electrode that transfers charges generated in the photoelectric conversion unit, as the circuit unit.

The present invention also includes a step of forming a light shielding portion having an opening in the photoelectric conversion portion prior to the step of patterning the optical system material in the method of manufacturing the solid-state imaging device.
With this configuration, it is possible to efficiently form an optical system that is aligned with the photoelectric conversion unit in a self-aligning manner by exposing from the back side, i.e., the semiconductor substrate side, without changing the structure. It becomes possible.

According to the present invention, in the method of manufacturing the solid-state imaging device, the step of forming the light shielding portion includes a step of forming a light shielding film on the charge transfer electrode via an insulating film.
With this configuration, it is possible to prevent malfunction due to light incident on the charge transfer electrode, and it is possible to reliably form the optical system in a self-aligning manner.

According to the present invention, in the method of manufacturing the solid-state imaging device, in the step of forming the light shielding portion, the charge transfer electrode is formed of a conductive film including a light shielding metal film, and the distance between the charge transfer electrodes is And a step of patterning the metal film so that light from the back surface of the semiconductor substrate becomes small enough not to reach the charge transfer electrode.
According to this configuration, the charge transfer electrode is made of a light-shielding material, so that the light from the back surface of the semiconductor substrate does not reach the charge transfer electrode without forming a separate light-shielding film. By forming so as to be small, the optical system can be patterned very easily and efficiently in a self-aligning manner.

  According to the present invention, in the method of manufacturing the solid-state imaging device, the step of forming the charge transfer electrode includes a step of forming a laminated film of a metal film and a polycrystalline silicon film.

According to the present invention, in the method for manufacturing the solid-state imaging device, the step of patterning the optical system material includes forming a photosensitive resin on the optical system material to be patterned, and the semiconductor substrate with respect to the photosensitive resin. It includes a step of forming a photosensitive resin pattern by performing exposure from the back side, and a step of transferring the photosensitive resin pattern to the optical system material.
According to this configuration, it is possible to easily pattern a desired optical system material.

In the method for manufacturing a solid-state imaging device according to the present invention, the step of patterning the optical material includes forming a photosensitive resin, and exposing the photosensitive resin from the back side of the semiconductor substrate. And a step of forming a pattern of the photosensitive resin.
According to this configuration, since an optical system such as a microlens can be formed with the photosensitive resin itself, pattern formation can be performed very easily.

  In the method for manufacturing a solid-state imaging device according to the present invention, the optical system material is a microlens.

  According to the present invention, in the method for manufacturing the solid-state imaging device, the optical system material is an in-layer lens.

The present invention further includes a step of forming an insulating film prior to the step of patterning the optical system material in the method of manufacturing the solid-state imaging device, and forming the pattern of the photosensitive resin on the insulating film. Etching with the pattern of the photosensitive resin as a mask to form an opening for forming an optical waveguide, and filling the opening with a high refractive index material constituting the optical waveguide.
With this configuration, since the opening for forming the optical waveguide can be formed by backside exposure, the optical waveguide can be formed very easily with high positional accuracy.

  According to the present invention, in the method for manufacturing a solid-state imaging device, the step of forming the insulating film includes a step of forming a BPSG film and flattening by heating, and forming a photosensitive resin layer on the BPSG film And a step of patterning the photosensitive resin layer by exposure from the semiconductor substrate side to form an opening; and etching the BPSG film using the photosensitive resin layer as a mask to form an optical waveguide. Forming an opening; and forming a silicon nitride film as an optical waveguide in the opening.

  Moreover, this invention is a solid-state image sensor formed using the manufacturing method of the said solid-state image sensor.

According to the present invention, in the solid-state imaging device, the charge transfer electrode includes a light-shielding metal film, and a distance between the charge transfer electrodes is 0.1 μm or less.
With this configuration, the charge transfer electrode can be used as it is as a light-shielding portion without forming a light-shielding film, so that a highly reliable optical system can be formed. Then, the optical axes can be aligned, and a large amount of light is taken in from above and light confinement is performed, whereby an optical waveguide structure with high light collection efficiency can be formed.

  According to the present invention, microlenses, in-layer lenses, optical waveguides, and the like can be formed in a self-aligned manner, so that they are not affected by misalignment, and are highly reliable with no sensitivity variation or deterioration due to vignetting. It is possible to provide a solid-state imaging device including

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
As shown in FIGS. 1 and 2, this solid-state imaging device is a solid-state imaging device including a photoelectric conversion unit and a charge transfer unit including a charge transfer electrode that transfers charges generated in the photoelectric conversion unit. The intra-layer lens 20 is patterned in a self-aligned manner by exposure from the back surface of the substrate 1. In the present embodiment, the charge transfer electrode is a charge transfer electrode made of a conductive film, which is configured by juxtaposing an interelectrode insulating film 4 on a gate insulating film 2 formed on the surface of a silicon substrate 1. 3 is formed around the charge transfer electrode via the upper insulating film 5 and includes a light-shielding film 7 made of a tungsten thin film, and from a BPSG (borophosphosilicate glass) film formed on the charge transfer electrode. An in-layer lens 20 is formed on the insulating film 10 to be self-aligned with the light shielding film 7 by backside exposure. The planarizing film 22, the color filter 50, the on-filter planarizing film 61, and the lens 60 are sequentially stacked on the upper layer of the intralayer lens 20. Here, FIG. 1 is a schematic cross-sectional view, FIG. 2 is a schematic plan view, and FIG. 1 is a cross-sectional view taken along line AA of FIG.

  According to the above configuration, since the inner lens 20 is patterned by self-alignment by backside exposure using the light-shielding film 7 covering the periphery of the charge transfer electrode 3 as a mask, there is no positional shift, and sensitivity variations and smear deterioration occur. It is possible to provide a solid-state imaging device that can prevent the light and improve the light condensing performance and that does not cause variations in sensitivity due to vignetting.

  Other structures are the same as those of a conventional solid-state imaging device, and include a photoelectric conversion unit 30 and a charge transfer unit 40 including a charge transfer electrode that transfers charges generated in the photoelectric conversion unit 30. An insulating film 10 made of a BPSG film filled in the photoelectric conversion portion is formed on the light shielding film 7 formed so as to have an opening in the conversion portion so that the surface is substantially flat. The upper layer is formed with an in-layer lens 20 and a planarizing film 22 made of a light-transmitting organic film, and a color filter 50 and a lens 60 are further formed thereon. 61 is a planarizing film on the filter.

  Thereby, it is possible to satisfactorily flatten the surface.

  The gate oxide film 2 is composed of a three-layer structure film of a silicon oxide film 2a, a silicon nitride film 2b, and a silicon oxide film 2c.

  Further, a photoelectric conversion unit 30 including a plurality of photodiode regions is formed on the silicon substrate 1, and a charge transfer unit 40 for transferring a signal charge detected by the photoelectric conversion unit 30 is provided between the photoelectric conversion units 30. It is formed.

  Although not shown in FIG. 2, the charge transfer channel through which the signal charge transferred by the charge transfer electrode moves is formed in a direction crossing the direction in which the charge transfer unit 40 extends.

  In FIG. 2, the description of the interelectrode insulating film formed near the boundary between the photodiode region 30 and the charge transfer portion 40 is omitted.

  As shown in FIG. 1, photoelectric conversion portions (30 a and 30 b), a charge transfer channel 33, a channel stop region 32, and a charge readout region 34 constituting the photodiode region 30 are formed in the silicon substrate 1. A gate oxide film 2 is formed on the surface of the substrate 1. On the surface of the gate oxide film 2, charge transfer electrodes (a first layer electrode made of a first layer conductive film and a second layer electrode made of a second layer conductive film) are juxtaposed across the interelectrode insulating film 4. Thus, a single-layer electrode structure is formed. Reference numeral 5 denotes an upper insulating film covering the charge transfer electrode.

  In this example, a so-called honeycomb-structured solid-state imaging device is shown, but it goes without saying that the present invention can also be applied to a square lattice type solid-state imaging device.

Next, the manufacturing process of this solid-state imaging device will be described in detail with reference to FIGS.
First, a photoelectric conversion unit and a charge transfer unit are formed on the silicon substrate 1 by a usual method. For example, the charge transfer unit is formed as follows. A silicon oxide film 2a having a film thickness of 15 nm, a silicon nitride film 2b having a film thickness of 50 nm, and a silicon oxide film 2c having a film thickness of 10 nm are formed on the surface of an n-type silicon substrate 1 having an impurity concentration of about 1.0 × 10 ¹⁶ cm ^−3. And a gate oxide film 2 having a three-layer structure is formed.

  Subsequently, a first-layer polycrystalline silicon film and a second-layer polycrystalline silicon film are juxtaposed on the gate oxide film 2 via an interelectrode insulating film 4 made of a silicon oxide film. 5 is formed (FIG. 3A). Although not shown, an antireflection film made of a silicon nitride film is formed on the photoelectric conversion portion.

  Thereafter, a tungsten thin film 7 is formed by CVD (FIG. 3B).

  Then, a resist pattern R1 having an opening in the photodiode region 30 is formed by photolithography (FIG. 3C). Then, the tungsten thin film is patterned by anisotropic etching (reactive ion etching) using the photoresist R1 as a mask (FIG. 4A).

  Then, the photoresist R1 is removed (FIG. 4B), and then a BPSG film is formed on the upper layer and heated and reflowed to form the planarizing film 10 (FIG. 4C).

  Then, a silicon nitride film 20 as an in-layer lens material is formed on this upper layer by CVD (FIG. 5A).

Then, a resist R2 is applied to this upper layer (FIG. 5B).
By exposing from the back surface of the silicon substrate in this state, an exposure region _RA is formed in the light shielding film 7 in a self-aligning manner (FIG. 6A).
Then, by performing development processing, a resist pattern R2 is formed only on the photodiode region 30 (FIG. 6B).
Further, the resist pattern R2 is melted by heating in this state, and formed into a hemisphere by surface tension (FIG. 7A).
Etchback is then performed using the resist pattern R3 formed in a hemispherical shape as a mask (FIG. 7B), and the shape of the resist pattern R3 is transferred to form an intralayer lens 20 made of a silicon nitride film (FIG. 7). (C)).

  Subsequently, after the organic film is applied to form the planarizing film 22, the color filter 50 and the on-filter planarizing film 61 are formed, and finally the microlens 60 is formed, so that the solid-state imaging device shown in FIG. It is formed.

  According to this method, since the inner lens 20 is formed in a self-aligned manner on the light-shielding film 7 that covers the charge transfer electrode, it is possible to reduce misalignment and to have a good light collecting property and high accuracy. A highly reliable solid-state imaging device can be formed.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
In the first embodiment, the light shielding film 7 covering the charge transfer electrode 3 is formed, and the inner lens 20 is patterned in a self-aligned manner with respect to the light shielding film 7, but in the present embodiment, As shown in FIG. 8, the resist R4 for forming the inner lens is patterned by backside exposure using the charge transfer electrode 3 itself as a mask. That is, in the present embodiment, the charge transfer electrode 3 is a two-layer film of a polycrystalline silicon layer 3S and a light-shielding tungsten layer 3M, and the distance between the electrodes is 0.1 μm, and the distance from the back surface of the semiconductor substrate is The light L is formed so as to be small enough not to reach the charge transfer electrode, and a photosensitive resin, that is, a photoresist is patterned by backside exposure using the charge transfer electrode itself as a mask instead of the light shielding film. The lens substrate made of a silicon nitride film is patterned using the above pattern as a mask to form the in-layer lens 20.
FIG. 9 shows the solid-state imaging device thus formed.

  According to this configuration, the charge transfer electrode 3 is made of a light-shielding material, so that light from the back surface of the semiconductor substrate reaches the charge transfer electrode without forming a separate light-shielding film. By forming the optical system so as to be small, the optical system can be patterned very easily and efficiently in a self-aligning manner. Here, when the thickness of the charge transfer electrode is about 200 nm, the light from the back surface of the semiconductor substrate hardly reaches the charge transfer electrode when the distance between the electrodes is 0.1 μm or less.

  Here, the allowable range of the inter-electrode distance is determined according to the wavelength of the exposure light source to be used.

(Embodiment 3)
Next, a third embodiment of the present invention will be described.
In the first and second embodiments, the back exposure is used in forming the intralayer lens 20, but in this embodiment, an example in which the back exposure is used for forming the optical waveguide will be described.
In the present embodiment, the process up to the step of FIG. 4C of the first embodiment is performed, and after the BPSG film 10 is planarized (FIG. 4C), the negative type is formed prior to the formation of the inner lens. Photoresist R5 is applied (FIG. 10A), and backside exposure is performed to form a pattern of photoresist R5 having an opening in the optical waveguide formation region (FIG. 10B). Using this as a mask, BPSG The film 10 is patterned (FIG. 11A), and an opening for forming an optical waveguide is formed in a self-aligned manner, and this opening is filled with a high refractive index film 8 such as a silicon nitride film to constitute an optical waveguide.
Others are formed by customary methods. FIG. 12 is a cross-sectional view showing the solid-state imaging device formed as described above.

  Hereinafter, the process of forming the solid-state imaging device having the optical waveguide structure according to the third embodiment will be described in detail.

3A to 4C of the first embodiment is performed, a BPSG film is formed on the surface of the substrate on which the light shielding film 7 has been patterned, and heated and reflowed, whereby the planarizing film 10 is formed. Form.
Prior to the formation of the inner lens, a negative type photoresist R5 is applied on the planarizing film 10 (FIG. 10A). Then, by performing backside exposure, a pattern of photoresist R5 having an opening in the optical waveguide formation region is formed (FIG. 10B). Using this as a mask, the BPSG film 10 is patterned (FIG. 11A), and an opening for forming an optical waveguide is formed in a self-aligning manner.
Subsequently, a film is formed by filling the opening with a high refractive index film 20 such as a silicon nitride film by a CVD method.
And it planarizes by CMP and comprises an optical waveguide (FIG.11 (b)).

Then, a resist R6 is applied to this upper layer.
In this state, as in the first embodiment, by exposing from the back surface of the silicon substrate, an exposure region is formed in the light shielding film 7 in a self-aligning manner (FIG. 12A).
Then, by performing development processing, a resist pattern R6 is formed only on the photodiode region 30 (FIG. 12B).
Furthermore, the resist pattern R6 is melted by heating in this state, and is shaped into a hemisphere by surface tension (FIG. 13A).
Etchback is performed using the resist pattern R3 formed in the hemispherical shape as a mask (FIG. 13B), and the shape of the resist pattern R3 is transferred to form an intralayer lens 20 made of a silicon nitride film (FIG. 13). (C)).

  Subsequently, after applying the organic film to form the planarizing film 22, the color filter 50 and the planarizing film 61 on the filter are formed, and finally the microlens 60 is formed. As shown in FIG. Is formed.

  According to this method, since the optical waveguide and the intralayer lens 20 are formed in a self-aligned manner on the light shielding film 7 covering the charge transfer electrode, it is possible to reduce misalignment and to have good light collecting properties. A highly accurate and reliable solid-state imaging device can be formed.

  In the solid-state imaging device according to the present invention, since the optical waveguide is formed in the light-shielding film in a self-aligning manner, if the transparent portion is filled with the transparent portion, the transparent portion is transparent. Since the material is filled, a large amount of light can be taken in and an optical waveguide structure with high light collection efficiency can be formed.

  According to the present invention, in the solid-state imaging device, the light-transmitting material is preferably an organic material, and according to this configuration, formation at a low temperature is possible.

  In the solid-state image pickup device according to the present invention, a color filter material may be filled in the opening of the BPSG film instead of silicon nitride constituting the optical waveguide. According to this configuration, it is not necessary to provide a separate filter layer, and the thickness can be further reduced. Since the filter is formed only at the light collecting portion, the light that is efficiently condensed is selectively wavelength-selected. Since it is adjusted and surrounded by a light shielding film, color mixing can be prevented.

  In the solid-state imaging device according to the present invention, the opening may be filled with a fluorescent agent. According to this configuration, it is not necessary to provide a separate phosphor layer, and the thickness can be further reduced. Since the phosphor is formed only in the light condensing part, the fluorescent light corresponding to the amount of light that has been efficiently collected. Can be made to emit light, and high sensitivity can be achieved.

  Further, according to the present invention, in the solid-state imaging device, the light shielding film may be tungsten, and according to this configuration, a light shielding film that can be easily formed by a CVD method and has a high light shielding property can be formed. Become. In addition, it can be formed in the same process as the wiring extraction of electrodes and the like.

Note that the light-shielding metal film is not limited to tungsten, and may be appropriately changed such as titanium (Ti), cobalt (Co), nickel (Ni).
In the solid-state imaging device, the light shielding film may be an aluminum thin film or an aluminum alloy thin film. According to this configuration, it is possible to form an optical waveguide structure that can be formed in the same process as the wiring of the peripheral circuit, is easy to process, and has high accuracy and high reliability. The light shielding film is not limited to an aluminum thin film or an aluminum alloy thin film, and may be a metal film having a light shielding property such as W.

  In addition, about a manufacturing method, it can change suitably, without being limited to the said embodiment.

  As described above, according to the present invention, it is possible to provide a solid-state imaging device that is not affected by the positional deviation of the microlens, the optical waveguide, and the in-layer lens, and that is free from variations and decreases in sensitivity due to vignetting. This makes it possible to form a fine and highly sensitive solid-state imaging device such as a small camera. Further, by filling the optical waveguide with a color filter material or a fluorescent agent, color mixture can be prevented and shrinking in the vertical direction can be achieved, and the margin for the light incident angle can be reduced.

It is sectional drawing which shows the solid-state image sensor of Embodiment 1 of this invention. It is a top view which shows the solid-state image sensor of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 2 of this invention. It is a figure which shows the solid-state image sensor of Embodiment 2 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 3 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 3 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 3 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 3 of this invention. It is a figure which shows the manufacturing process of the solid-state image sensor of Embodiment 3 of this invention. It is a figure which shows an example of the solid-state image sensor of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Silicon substrate 2 Gate oxide film 3a 1st layer polycrystalline silicon film 3b 2nd layer polycrystalline silicon film 4 Interelectrode insulating film 5 Silicon oxide film (insulating film)
7 light shielding film 8 antireflection film 10 flattening film (BPSG film)
22 translucent film 30 photoelectric conversion unit 40 charge transfer unit 50 color filter 60 microlens 61 flattening film

Claims (14)

Forming a photoelectric conversion part on a semiconductor substrate surface;
A method of manufacturing a solid-state imaging device including a step of forming an optical system on the photoelectric conversion unit,
The step of forming the optical system includes the step of forming an optical system material on the substrate surface on which the photoelectric conversion unit and the circuit unit connected to the photoelectric conversion unit are formed,
And a step of patterning the optical material by performing exposure from the back side of the semiconductor substrate. It is a manufacturing method of the solid-state image sensing device according to claim 1,
A method for manufacturing a solid-state imaging device, comprising: forming a charge transfer portion including a charge transfer electrode for transferring a charge generated in the photoelectric conversion portion as the circuit portion. It is a manufacturing method of the solid-state image sensing device according to claim 2,
Prior to patterning the optical material,
A method for manufacturing a solid-state imaging device, including a step of forming a light shielding portion so that an opening is formed in the photoelectric conversion portion. It is a manufacturing method of the solid-state image sensing device according to claim 3,
The step of forming the light shielding portion includes:
A method of manufacturing a solid-state imaging device, including a step of forming a light shielding film on the charge transfer electrode via an insulating film. It is a manufacturing method of the solid-state image sensing device according to claim 3,
The step of forming the light shielding portion includes:
The charge transfer electrodes are formed of a conductive film including a light-shielding metal film, and the distance between the charge transfer electrodes is reduced to such an extent that light from the back surface of the semiconductor substrate does not reach the charge transfer electrodes. And a method of manufacturing a solid-state imaging device, including a step of patterning the metal film. It is a manufacturing method of the solid-state image sensing device according to claim 5,
The step of forming the charge transfer electrode includes a step of forming a laminated film of a metal film and a polycrystalline silicon film. A method for manufacturing a solid-state imaging device according to any one of claims 1 to 5,
The step of patterning the optical system material includes:
Form a photosensitive resin on the optical material to be patterned,
By exposing the photosensitive resin from the back side of the semiconductor substrate,
Forming a photosensitive resin pattern;
And a step of transferring the pattern of the photosensitive resin to the optical system material. A method for manufacturing a solid-state imaging device according to any one of claims 1 to 5,
The step of patterning the optical system material includes:
Forming a photosensitive resin,
By exposing the photosensitive resin from the back side of the semiconductor substrate,
And a step of forming a pattern of a photosensitive resin. It is a manufacturing method of the solid-state image sensing device according to claim 7 or 8,
The optical system material is a manufacturing method of a solid-state imaging device which is a microlens. It is a manufacturing method of the solid-state image sensing device according to claim 7 or 8,
The optical system material is a manufacturing method of a solid-state imaging device which is an in-layer lens. It is a manufacturing method of the solid-state image sensing device according to claim 7,
Prior to patterning the optical material,
Including a step of forming an insulating film,
Forming a pattern of the photosensitive resin on the insulating film;
Etching with the photosensitive resin pattern as a mask to form an opening for forming an optical waveguide,
A method for manufacturing a solid-state imaging device, comprising a step of filling a high refractive index material constituting an optical waveguide in the opening. It is a manufacturing method of the solid-state image sensing device according to claim 11,
The step of forming the insulating film includes a step of forming a BPSG film and flattening by heating,
Forming a photosensitive resin layer on the BPSG film;
Patterning the photosensitive resin layer by exposure from the semiconductor substrate side and forming an opening;
Etching the BPSG film using the photosensitive resin layer as a mask to form an opening for forming an optical waveguide;
Forming a silicon nitride film as an optical waveguide in the opening.   A solid-state imaging device formed by using the method for manufacturing a solid-state imaging device according to claim 1. The solid-state imaging device according to claim 13,
The charge transfer electrode includes a light-shielding metal film, and a distance between the charge transfer electrodes is 0.1 μm or less.

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