JP2007311662A - Photoelectric converting device, manufacturing method thereof, and focus detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a converting device capable of suppressing cracking of a layer, and to provide a manufacturing method of the photoelectric converting device. <P>SOLUTION: The photoelectric converting device 200 comprises a photoelectric converting element 102, microlenses 109, a flattening film 108, and a transparent film 210. The microlenses 109 converge incident light on the photoelectric converting element 102. The flattening film 108 is disposed between the photoelectric converting element 102 and microlenses 109. The transparent film 210 is arranged over the microlenses 109 and flattening film 108. The transparent film 210 has a first opening 210a. The flattening film 108 has a through-hole 108a. The through-hole 108a is aligned with the first opening 210a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion device, a method for manufacturing a photoelectric conversion device, and a focus detection system.

Conventionally, there has been proposed a photoelectric conversion device used in a phase difference detection method, which is a method of detecting a defocus amount via a phase difference and focusing the focus (for example, see Patent Documents 1 to 3).
US Pat. No. 4,410,804 JP 2001-83407 A JP 2001-124984 A

  A camera using a phase difference detection method has an advantage that a defocus amount can be obtained as compared with a camera using a contrast detection method, so that the time until focusing is significantly reduced. Patent Documents 1 to 3 show photoelectric conversion devices used for the phase difference detection method.

  However, in the photoelectric conversion device used for the phase difference detection method, the following structure is desired in order to detect the phase difference with high accuracy. For example, an interval between the photoelectric conversion element and a microlens that collects light on the photoelectric conversion element is secured at a first interval or more (for example, 30 μm or more). For this reason, it exists in the tendency for the thickness of the layer arrange | positioned between a photoelectric conversion element and a micro lens to become thick. When such a layer is dry-etched, the photoresist serving as a mask tends to be formed to be thick.

  In this case, for example, in dry etching (for example, RIE), heat generated in the etched portion may be difficult to be released through the surface or the semiconductor substrate. Thereby, since the temperature difference between the back surface portion and the etched portion of the semiconductor substrate may become large, there is a possibility that cracks may occur in the layer due to thermal stress. In addition, the photoresist may be carbonized by the heat, and peeling and removal may be difficult. Therefore, when forming a through hole or the like in an imaging device having a thick layer, the yield may be reduced.

  Therefore, in view of such problems, an object of the present invention is to reduce the thickness of a photoresist necessary for forming, for example, a through hole and improve the yield.

  The photoelectric conversion device according to the present invention includes a photoelectric conversion element, a microlens, a layer, and a transparent film. The microlens condenses incident light on the photoelectric conversion element. The layer is disposed between the photoelectric conversion element and the microlens. The transparent film is disposed so as to cover the microlens and the layer. The transparent film has a refractive index smaller than that of the microlens. The transparent film has an opening. The layer has a through hole. The through hole is aligned with the opening.

  Such a configuration of the photoelectric conversion device contributes to reducing the thickness of the photoresist necessary for forming, for example, a through hole. Specifically, the opening of the transparent film can be formed using a photoresist having a thickness smaller than the thickness of the layer. A through hole can be formed by etching the layer using the transparent film as a mask.

  Thereby, for example, the thickness of the photoresist necessary for forming a through hole or the like can be reduced. Therefore, formation of a through-hole etc. becomes easy and a yield can be improved.

  The manufacturing method of the photoelectric conversion device according to the present invention includes the following steps. In the first step, a layer is formed above the photoelectric conversion element. In the second step, a microlens is formed on the layer. In the third step, a transparent film is formed so as to cover the microlens and the layer. In the fourth step, an opening is formed by etching the transparent film by a photolithography process using a photoresist. In the fifth step, the photoresist is removed. In the sixth step, the layer is etched using the transparent film as a mask to form a through hole in the layer. The through hole is aligned with the opening.

  Such a method for manufacturing a photoelectric conversion device contributes to reducing the thickness of a photoresist necessary for forming, for example, a through hole. For example, a transparent film opening can be formed using a photoresist having a thickness smaller than the thickness of the layer. Then, by etching the layer using the transparent film as a mask, a through hole aligned with the opening can be formed.

  In this manner, an opening can be formed in the transparent film by a photolithography process using a photoresist, and a through hole can be formed by etching the underlying layer using this transparent film as a mask. Thereby, for example, the thickness of the photoresist necessary for forming a through hole or the like can be reduced, and the yield can be improved.

  Here, the through hole or the like is a through hole for an electrode or a scribe line provided in a semiconductor substrate.

  With the configuration of the photoelectric conversion device according to the present invention, for example, the thickness of a photoresist necessary for forming a through hole or the like can be reduced. Then, the yield of the photoelectric conversion device can be improved.

  In the method for manufacturing a photoelectric conversion device according to the present invention, for example, the thickness of a photoresist necessary for forming a through hole or the like can be reduced. The yield of the photoelectric conversion device can be improved.

<Problem of the present invention>
The problems of the present invention found by the inventors will be described in detail with reference to FIGS. FIG. 7 is a cross-sectional view illustrating the structure of the photoelectric conversion device. 8-10 is process sectional drawing which shows the manufacturing method of a photoelectric conversion apparatus.

(Configuration and operation of photoelectric conversion device)
The photoelectric conversion apparatus 100 is an apparatus that detects a focal position using, for example, a phase difference detection method. As shown in FIG. 7, the photoelectric conversion device 100 mainly includes a semiconductor substrate 101, a photoelectric conversion element 102, a wiring 103, a light shielding film 104, an interlayer insulating film 105, a passivation film 106, an electrode portion 107, a planarizing film 108, and a micro A lens 109 is provided.

  The semiconductor substrate 101 has a substantially plate shape and is formed of a semiconductor such as silicon.

  The photoelectric conversion element 102 is provided on the semiconductor substrate 101. Light incident on the photoelectric conversion element 102 is converted into a charge signal. This charge signal can be provided to the gate of an amplification transistor or the like via a transfer transistor or the like, for example.

  The wiring 103 is a conductor that connects between elements constituting such a circuit. The wiring 103 is formed of at least one of a metal such as polysilicon or tungsten, or a metal silicide such as tungsten silicide.

  The light shielding film 104 is provided above part of the photoelectric conversion element 102 and the wiring 103. The light shielding film 104 is made of aluminum, titanium, tungsten, or the like.

  The electrode portion 107 is located near the periphery of the semiconductor substrate 101 and is provided further above the light shielding film 104. The electrode portion 107 is made of aluminum or the like.

The interlayer insulating film 105 is provided between the semiconductor substrate 101 and the electrode part 107 so as to fill a gap between the semiconductor substrate 101, the light shielding film 104, and the electrode part 107. Thereby, the semiconductor substrate 101, the wiring 103, the light shielding film 104, and the electrode part 107 are insulated from each other. This interlayer insulating film 105 is formed of a SiO ₂ film or the like.

  The passivation film 106 is formed on the interlayer insulating film 105. Thereby, the interlayer insulating film 105, the photoelectric conversion element 102, the wiring 103, and the like are protected mechanically and chemically.

  The planarization film 108 is formed on the passivation film 106 and the electrode part 107. The upper surface of the planarizing film 108 is planarized. The planarizing film 108 is formed of an acrylic resin or an epoxy resin.

  Here, the planarization film 108 has a through hole 108a. The through hole 108 a penetrates the planarizing film 108 so as to go upward from the upper surface of the electrode portion 107. That is, the electrode portion 107 is provided at the bottom of the through hole 108a. Note that the thickness D108 of the planarization film 108 is formed to be equal to or greater than the first thickness (for example, 30 μm or more) so that sufficient focus detection characteristics can be obtained in the case of an imaging device used for the phase difference detection method, for example. It is necessary to

  The microlens 109 is formed on the planarizing film 108 so as to have a convex curved surface. Thereby, the incident light on the microlens 109 can be condensed on the photoelectric conversion element 102 via the planarization film 108 and the interlayer insulating film 105. The micro lens 109 is made of a positive i-line photoresist or the like.

(Manufacturing method of photoelectric conversion device)
A method for manufacturing a photoelectric conversion device will be described with reference to the cross-sectional view of FIG. 7 and the cross-sectional views of steps in FIGS.

  In the first step S101, a planarizing film is formed above the photoelectric conversion element in the wafer on which the photoelectric conversion device is formed. That is, as shown in FIG. 8, the planarization film 108 is formed above the photoelectric conversion element 102 and on the passivation film 106.

  In the second step S102, a microlens is formed on the planarizing film. That is, a positive i-line photoresist is applied on the planarizing film 108. The positive i-line photoresist is patterned in a rectangular shape in a top view at a predetermined position by a photolithography method. Thereafter, the positive i-line photoresist is heat-treated at a temperature of 140 ° C. to 160 ° C., for example, and has an upwardly convex curved surface as shown in FIG. Thereby, the microlens 109 is formed.

  In the seventh step S107, a photolithography process using a photoresist is performed to form a through hole in the planarization film. That is, as shown in FIG. 9, a photoresist 111 is applied on the planarizing film 108 and the microlens 109. Then, a second opening 111 a is formed in the photoresist 111 at a position above the electrode portion 107 by photolithography. Thereafter, baking is performed at a temperature of about 120 ° C. for about 300 seconds. Further, the wafer is placed in a dry etching apparatus. At this time, the wafer is placed in the chamber of the dry etching apparatus so that the back surface of the wafer (the back surface of the semiconductor substrate 101) is in contact with the base of the dry etching apparatus. Then, as shown in FIG. 10, anisotropic dry etching is performed using the photoresist 111 in which the second opening 111 a is formed as a mask to form a through hole 108 a in the planarizing film 108.

  Here, since both the photoresist 111 and the planarizing film 108 are formed of an organic material, the etching rate of the photoresist 111 and the etching rate of the planarizing film 108 are substantially equal. For this reason, the thickness of the photoresist 111 is reduced from D111a to D111b (≈D111a-D108) at the same time as the through hole 108a having the depth D108 is formed in the planarizing film 108.

  In the eighth step S108, the photoresist is removed. That is, the photoresist 111 remaining after dry etching is removed with a stripping solution containing an organic solvent, as shown in FIG. Thereafter, the wafer is rinsed and dried by a spin dry method.

  As described above, the etching rate of the planarizing film 108 and the etching rate of the photoresist 111 are the same under the etching conditions under which the planarizing film 108 is etched. Accordingly, when the thickness D108 of the planarizing film 108 is increased (for example, 30 μm or more), the thickness D111a of the photoresist 111 used for anisotropic dry etching tends to be increased (for example, 30 μm or more). . In particular, the thickness D111a (≈D108 + D111b, see FIG. 10) of the photoresist 111 is larger than the thickness D108 of the planarization film 108.

  In this case, in the seventh step S107, the heat generated in the etched portion of the planarizing film 108 that is dry-etched tends to be difficult to be released through the semiconductor substrate 101 to the base of the dry etching apparatus. As a result, the temperature difference between the back surface portion and the etched portion of the semiconductor substrate 101 may become large, and there is a possibility that cracks may occur in the planarization film 108 due to thermal stress.

  Further, the photoresist 111 may be heated and carbonized through the planarization film 108 due to heat generated in the etched portion. The carbonized portion in the photoresist 111 is difficult to dissolve in a stripping solution containing an organic solvent, and thus may not be stripped and removed by the stripping solution.

  As described above, when a crack occurs in the planarizing film 108 or when a carbonized portion of the photoresist 111 remains, the yield of the photoelectric conversion device 100 decreases.

  Such a decrease in yield occurs not only in the photoelectric conversion device used for the phase difference detection method, but also in a photoelectric conversion device in which the distance between the photoelectric conversion element and the microlens that collects light on the photoelectric conversion element is large. there is a possibility.

<Photoelectric Conversion Device According to a Preferred Embodiment of the Present Invention>
A photoelectric conversion device according to a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view illustrating a structure of a photoelectric conversion device. 2-6 is process sectional drawing which shows the manufacturing method of a photoelectric conversion apparatus. Below, it demonstrates centering on a different part from said photoelectric conversion apparatus 100, About the same part, the same number is shown and description is abbreviate | omitted.

(Configuration and operation of photoelectric conversion device)
As shown in FIG. 1, the photoelectric conversion device 200 is different from the photoelectric conversion device 100 in that it further includes a transparent film 210.

The transparent film 210 is disposed so as to cover the microlens 109 and the planarizing film 108. The transparent film 210 is made of, for example, a SiO ₂ film.

  Here, the transparent film 210 has a first opening 210a. The first opening 210a is formed by removing a portion of the transparent film 210 located above the electrode portion 107. Further, the through hole 108a of the planarizing film 108 is aligned with the first opening 210a.

(Manufacturing method of photoelectric conversion device)
A method for manufacturing a photoelectric conversion device according to a preferred embodiment of the present invention will be described with reference to the cross-sectional view of FIG. 1 and the cross-sectional views of FIGS.

  The first step S101 and the second step S102 are the same as the method for manufacturing the photoelectric conversion device 100 as shown in FIG.

  In the third step S203, a transparent film is formed so as to cover the microlens and the planarizing film. That is, as shown in FIG. 3, the transparent film 210 is deposited on the microlens 109 and the planarizing film 108 by plasma CVD.

  Here, the thickness D210 of the transparent film 210 is sufficiently smaller than the thickness D108 of the planarization film 108. Further, the thickness D210 of the transparent film 210 is sufficiently smaller than the thickness D211a of the photoresist 211 described later.

In the fourth step S204, the transparent film is etched to form the first opening by a photolithography process using a photoresist. That is, as shown in FIG. 4, a photoresist 211 is applied on the transparent film 210. Then, a third opening 211a is formed at a position above the electrode portion 107 in the photoresist 211 by photolithography. Thereafter, baking is performed. Further, a wafer (in which the photoelectric conversion device 200 is formed) is placed in a dry etching device. Then, as shown in FIG. 5, anisotropic dry etching is performed using the photoresist 211 in which the third opening 211 a is formed as a mask to form the first opening 210 a in the transparent film 210. The anisotropic dry etching is performed under conditions such that the transparent film 210 (eg, SiO ₂ ) is selectively etched with respect to the photoresist (organic material). For example, in anisotropic dry etching, a fluorinated gas (CF ₄ ) is used as an etching gas.

  At this time, the thickness of the photoresist 211 is reduced from D211a to D211b at the same time when the first opening 210a having the depth D210 is formed in the transparent film 210. Here, the thickness D211a of the photoresist 211 is sufficient as long as the photoresist 211 remains when the transparent film 210 having the thickness D210 is etched.

  In the fifth step S205, the photoresist is removed. That is, the photoresist 211 remaining after the dry etching is removed with a stripping solution containing an organic solvent, as shown in FIG. Thereafter, the wafer is rinsed and dried by a spin dry method.

In the sixth step S206, the planarizing film is etched using the transparent film as a mask, and a through hole aligned with the first opening is formed in the planarizing film. That is, as shown in FIG. 1, anisotropic dry etching is performed using the transparent film 210 as a mask, and a through hole 108 a is formed in the planarizing film 108. Note that anisotropic dry etching is performed under conditions such that the planarization film 108 (organic material) is selectively etched with respect to the electrode portion 107 (metal). For example, in anisotropic dry etching, oxygen gas (O ₂ ) and fluorinated gas (CF ₄ ) are used as etching gases. At this time, the electrode portion 107 can be used as an etching stop layer.

  Here, it is easy to make the etching rate of the transparent film 210 slower than the etching rate of the planarizing film 108. For this reason, when the planarizing film 108 is etched, the transparent film 210 is hardly etched. That is, the first opening 210a is formed in the transparent film 210 by a photolithography process using a photoresist, and the planarizing film 108 thereunder can be etched using the transparent film 210 as a mask. Thereby, for example, the thickness of the photoresist 211 necessary for forming the through hole 108a and the like is reduced.

  As described above, even if the thickness D108 of the planarization film 108 is increased (for example, 30 μm or more), the thickness D211a of the photoresist 211 used for anisotropic dry etching is equal to the thickness D111a of the photoresist 111. (Refer to FIG. 9). In particular, the thickness D111a of the photoresist 111 (≈D108 + D111b, see FIG. 10) is thicker than the thickness D108 of the planarization film 108, whereas the thickness D211a of the photoresist 211 is the thickness D108 of the planarization film 108. It is thinner.

  In this case, heat generated in the etched portion of the transparent film 210 that is dry-etched is easily released from the surface. Therefore, it is possible to reduce the heat generated in the etched portion that is dry-etched.

(Characteristics regarding the embodiment)
(1)
The configuration of the photoelectric conversion device 200 contributes to reducing the thickness D211a of the photoresist 211 necessary for forming the through hole 108a and the like, for example. For example, the opening 210a of the transparent film 210 is formed using a photoresist 211 having a thickness smaller than the thickness D108 of the planarizing film 108. Then, by etching the planarizing film 108 using the transparent film 210 as a mask, the through hole 108a aligned with the opening 210a is formed. Here, by disposing the transparent film 210 having a refractive index smaller than that of the microlens formed on the planarizing film 108 also on the microlens, reflection of light incident on the microlens on the incident surface is reduced. It is possible.

  As described above, the first opening 210a is formed in the transparent film 210 by the photolithography process using the photoresist 211, and the planarizing film 108 under the transparent film 210 is etched to form the through hole 108a. The Thereby, for example, the thickness of the photoresist 211 necessary for forming the through hole 108a or the like is reduced.

  That is, since the thickness D211a of the photoresist 211 formed on the planarizing film 108 is reduced, heat generated in the planarizing film 108 is easily released. For this reason, since the thermal stress acting on the planarizing film 108 is reduced, the occurrence of cracks in the planarizing film 108 is suppressed.

  Further, since the heat generated in the planarization film 108 is easily released, the heating of the photoresist 211 through the planarization film 108 is also reduced. Thereby, carbonization of the photoresist 211 is suppressed.

  As a result, the yield can be improved.

(2)
Here, the transparent film 210 is formed of, for example, a SiO2 film. That is, it can be easily formed using existing techniques.

(3)
Here, in the fourth step S204, the photoresist 211 is formed on the transparent film 210 so that the thickness D211a is smaller than the thickness D108 of the planarizing film. That is, the thickness D211a of the photoresist 211 can be kept low because it is sufficient that the photoresist 211 remains even if the transparent film 210 having the thickness D210 is etched.

(Modification)
(A) In the present embodiment, the photoelectric conversion device for detecting the focal position has been mainly described. However, the idea shown in this embodiment can also be applied to a photoelectric conversion device for other purposes as long as the thickness of the layer disposed between the photoelectric conversion element and the microlens is large. For example, the idea shown in this embodiment can be applied to a photoelectric conversion device for obtaining image information.

(B) The transparent film may be formed of at least one of a SiON film, a SiO ₂ film, and a polyurea film. Even in this case, in anisotropic dry etching, the etching rate of the transparent film is slower than the etching rate of the planarizing film 108. For this reason, it is possible to use a transparent film as a maximum. That is, the through hole 108a can be formed in the planarizing film 108 without using the photoresist 211 (using a sufficiently thin transparent film).

(C) The transparent film may be formed of SiON. In this case, in the third step S203, the composition ratio of the mixed gas (SiH ₄ , O ₂ , N ₂ ) when the transparent film 210 is deposited by the plasma CVD method is adjusted. Thereby, the refractive index of the transparent film can be adjusted (for example, changed to 1.46 to 1.85). That is, the focal position of the microlens 109 can be adjusted without changing the microlens 109.

  (D) The transparent film may be formed of a polyurea film. In this case, it is easy to make the refractive index of the transparent film lower than the refractive index of the microlens 109. As a result, a large amount of light passing through the transparent film and entering the microlens 109 can be secured.

  Such a modification makes it possible to reduce reflection when light enters the microlens.

<Application of photoelectric conversion device>
As an application of the photoelectric conversion device of the present invention, a case where it is applied to an imaging system is shown.

  FIG. 11 is a block diagram showing an embodiment when used in a still camera as an imaging system. In FIG. 11, reference numeral 301 denotes a barrier that serves as a lens switch and a main switch, 302 denotes a lens that forms an optical image of a subject on the photoelectric conversion device 304, and 303 denotes an aperture for changing the amount of light that has passed through the lens 302. Although not shown, a drive unit for driving these optical systems is provided. Reference numeral 304 denotes a photoelectric conversion device for capturing a subject imaged by the lens 302 as an image signal.

  Further, as a focus detection system, 305 photoelectric converters for AE (Auto Exposure) AF (Auto Focus) are provided. The AF and AE photoelectric conversion devices may have different configurations. Here, in 305, the photoelectric conversion device described in the above embodiment is used. Also in 304, the above-described photoelectric conversion device is used.

  Reference numeral 306 denotes an imaging signal processing circuit that performs signal processing on image signals, AE signals, and AF signals output from the photoelectric conversion device 304 and the AEAF photoelectric conversion device 305. Reference numeral 307 denotes an A / D converter that performs analog-digital conversion on the output from the imaging signal processing circuit 306. Reference numeral 308 denotes a signal processing unit that compresses various corrections and data for image data output from the A / D converter 307. It is. Further, reference numeral 309 denotes a timing generation unit that outputs various timing signals to the solid-state imaging device 304, the imaging signal processing circuit 306, the A / D converter 307, the signal processing unit 308, and the like. Reference numeral 310 denotes an overall control / arithmetic unit that controls various calculations and the entire camera, and 311 denotes a memory unit for temporarily storing image data. Reference numeral 312 denotes an interface unit for performing recording or reading on a recording medium. Reference numeral 313 denotes a removable recording medium such as a semiconductor memory for recording or reading image data, and 314 denotes an interface unit for communicating with an external computer or the like.

  An operation at the time of shooting of the still camera having such a configuration will be described. When the barrier 301 is opened, the main power supply is turned on, then the control system power supply is turned on, and the power supply of the imaging system circuit such as the A / D converter 307 is turned on. Next, in order to control the exposure amount, the overall control / arithmetic unit 310 opens the diaphragm 303, and the signal output from the AE sensor of the AEAF photoelectric conversion device 305 is converted by the A / D converter 307, Input to the processing unit 308. Based on the data, the exposure calculation is performed by the overall control / calculation unit 310.

  The brightness is determined based on the result of the photometry, and the overall control / calculation unit 310 adjusts the diaphragm 303 according to the result. The overall control / calculation unit 310 performs the above-described phase difference detection based on the signal output from the AF photoelectric conversion device of the AEAF photoelectric conversion device 305. Thereafter, the lens 302 is driven to determine whether or not it is in focus. When it is determined that the lens is not in focus, the lens 302 is driven again to perform autofocus control.

  Next, the main exposure starts after the in-focus state is confirmed. When the exposure is completed, the image signal output from the photoelectric conversion device 304 is A / D converted by the A / D converter 307, passes through the signal processing unit 308, and is written in the memory unit 311 by the overall control / calculation 310. Thereafter, the data stored in the memory unit 311 is recorded on the removable recording medium 313 through the recording medium control I / F unit 312 under the control of the overall control / arithmetic unit 310. Further, it may be input directly to a computer or the like through the external I / F unit 314.

  With such an operation, an image can be obtained.

Sectional drawing which shows the structure of the photoelectric conversion apparatus which concerns on suitable embodiment of this invention. Process sectional drawing which shows the manufacturing method of the photoelectric conversion apparatus which concerns on suitable embodiment of this invention. Process sectional drawing which shows the manufacturing method of the photoelectric conversion apparatus which concerns on suitable embodiment of this invention. Process sectional drawing which shows the manufacturing method of the photoelectric conversion apparatus which concerns on suitable embodiment of this invention. Process sectional drawing which shows the manufacturing method of the photoelectric conversion apparatus which concerns on suitable embodiment of this invention. Process sectional drawing which shows the manufacturing method of the photoelectric conversion apparatus which concerns on suitable embodiment of this invention. Sectional drawing which shows the structure of a photoelectric conversion apparatus. Process sectional drawing which shows the manufacturing method of a photoelectric conversion apparatus. Process sectional drawing which shows the manufacturing method of a photoelectric conversion apparatus. Process sectional drawing which shows the manufacturing method of a photoelectric conversion apparatus. The block diagram which shows an example of an imaging system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,200 Photoelectric conversion apparatus 101 Semiconductor substrate 102 Photoelectric conversion element 107 Electrode part 108 Flattening film | membrane 108a Through-hole 109 Micro lens 111,211 Photoresist 210 Transparent film 210a 1st opening

Claims (6)

A photoelectric conversion element;
A microlens that focuses incident light on the photoelectric conversion element;
A layer disposed between the photoelectric conversion element and the microlens;
A transparent film disposed so as to cover the microlens and the layer, and having a refractive index smaller than that of the microlens;
With
The transparent film has an opening;
The layer has through holes aligned with the openings;
Photoelectric conversion device. Further comprising an electrode part at the bottom of the through hole,
2. The photoelectric conversion device according to claim 1. The transparent film includes at least one of a SiO film, a SiON film, and a polyurea film.
The photoelectric conversion device according to claim 1. The transparent film has an etching selectivity lower than that of the layer in an etching condition when the through hole is formed in the layer.
The photoelectric conversion device according to claim 1. A first step of forming a layer above the photoelectric conversion element;
A second step of forming a microlens on the layer;
A third step of forming a transparent film so as to cover the microlens and the layer;
A fourth step of forming an opening by etching the transparent film by a photolithography process using a photoresist;
A fifth step of removing the photoresist;
Etching the layer using the transparent film as a mask to form a through hole in the layer aligned with the opening;
With
A method for manufacturing a photoelectric conversion device. The photoelectric conversion device according to any one of claims 1 to 4,
An optical system for imaging light onto the photoelectric conversion device;
A signal processing circuit for processing an output signal from the photoelectric conversion device;
A drive unit for driving the optical system based on a signal from the signal processing circuit;
With
Focus detection system based on phase difference detection.

Images