JP2010016242A - Photoelectric conversion device, imaging system, and method of manufacturing photoelectric conversion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the reflection of a light incident directed to a photoelectric conversion portion and reduce dangling bonds at the light-receiving surface of the photoelectric conversion portion. <P>SOLUTION: The photoelectric conversion device includes a photoelectric conversion portion having a light-receiving surface, and a multilayer wiring structure that defines an opening region on the upper part of the photoelectric conversion portion. The multilayer wiring structure includes an uppermost wiring layer that defines contour sides at the opening region, a hydrogen containing layer having the same pattern as that of the uppermost wiring layer, disposed on the uppermost wiring layer in such a way that the pattern thereof perfectly overlaps the uppermost wiring layer when viewed from the direction perpendicular to the light-receiving surface, and containing hydrogen, an interlayer insulating film that fills at least the opening region, and a protective film that extends so as to cover the uppermost wiring layer, the hydrogen containing layer, and the interlayer insulating film, and having a hydrogen content lower than that of the hydrogen containing layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In the solid-state imaging device described in Patent Document 1, as shown in FIG. 1 of Patent Document 1, a plurality of wiring portions are formed on a substrate including a photodiode, and the uppermost wiring portion is formed. A passivation film for protecting the substrate is formed. Here, since the passivation film is formed in a gas atmosphere containing a large amount of hydrogen by a plasma CVD method, it contains a large amount of hydrogen. As a result, according to Patent Document 1, the silicon non-terminated portion (dangling bond) on the surface of the silicon substrate is easily terminated with hydrogen, and the dangling bond that is a dark current generation source (in the photodiode) is reduced. It is supposed to be possible.

On the other hand, in the solid-state imaging device described in Patent Document 2, copper wiring formed by a dual damascene process is used. In this dual damascene process, an interlayer insulating film is formed, a wiring groove is formed in the interlayer insulating film, a barrier film is formed on the inner wall surface (bottom wall surface and side wall surface) of the wiring groove, and then on the barrier film. Cover with copper. Then, after the portions other than the wiring grooves in the coated copper are removed by the CMP method, diffusion is performed on the copper (copper wiring) by the CVD method in order to prevent diffusion of copper to be the wiring remaining in the wiring grooves. A prevention film is formed.
Japanese Patent Laid-Open No. 2006-210585 JP 2003-324189 A

  In the solid-state imaging device described in Patent Document 1, as shown in FIG. 1 of Patent Document 1, in order to protect the silicon substrate, a passivation film containing a large amount of hydrogen is formed so as to cover the entire surface of the silicon substrate. .

  On the other hand, Patent Document 2 does not disclose providing a layer for easily terminating dangling bonds of silicon in a silicon substrate with hydrogen in a solid-state imaging device.

  In Patent Document 2, it is described with reference to FIG. 9 of Patent Document 2 that a diffusion prevention film for preventing copper diffusion may be formed only on the upper surface portion of the copper wiring.

  Here, the copper wiring and the diffusion prevention film are formed using different mask patterns as shown in FIG. That is, since a process margin is taken into consideration for misalignment and the like with respect to the copper wiring pattern, the pattern of the diffusion prevention film is wider than the copper wiring pattern. Further, this diffusion prevention film is considered to be formed with a wider width than the copper wiring, as shown in FIG. 9 of Patent Document 2, in order to reliably prevent the copper wiring from diffusing in the heat treatment after the formation. It is done.

  In this case, the light incident toward the opening region defined by the copper wiring may be reflected by the portion of the diffusion prevention film that protrudes toward the opening region than the copper wiring.

  An object of the present invention is to reduce reflection of light incident on a photoelectric conversion unit and reduce dangling bonds on a light receiving surface of the photoelectric conversion unit.

  The photoelectric conversion device according to the first aspect of the present invention includes a photoelectric conversion unit having a light receiving surface and a multilayer wiring structure that defines an opening region above the photoelectric conversion unit, and the multilayer wiring structure includes the opening region. An uppermost wiring layer that defines the contour side of the uppermost wiring layer, and has the same pattern as the uppermost wiring layer, and the uppermost wiring layer completely overlaps the uppermost wiring layer when viewed from a direction perpendicular to the light receiving surface. A hydrogen-containing layer containing hydrogen, an interlayer insulating film filling at least the opening region, and extending so as to cover the uppermost wiring layer, the hydrogen-containing layer, and the interlayer insulating film. And a protective film having a lower hydrogen content than the hydrogen-containing layer.

  An imaging system according to a second aspect of the present invention includes a photoelectric conversion device according to the first aspect of the present invention, an optical system that forms an image on the imaging surface of the photoelectric conversion device, and a signal output from the photoelectric conversion device. And a signal processing unit that generates image data.

  A method for manufacturing a photoelectric conversion device according to a third aspect of the present invention is a method for manufacturing a photoelectric conversion device having a photoelectric conversion part having a light receiving surface and an interlayer insulating film above the photoelectric conversion part, wherein the interlayer A first step of forming a metal film on the insulating film, a second step of forming a dielectric film containing hydrogen on the metal film, and the metal film using one mask pattern Forming the uppermost wiring layer that defines the contour side in the opening region above the photoelectric conversion unit, and patterning the dielectric film, thereby forming the same pattern as the uppermost wiring layer And forming a hydrogen-containing layer disposed on the uppermost wiring layer so as to completely overlap the uppermost wiring layer when viewed from a direction perpendicular to the light receiving surface. And a third step After a fourth step of forming a protective film having a lower hydrogen content than the hydrogen-containing layer so as to cover the upper wiring layer, the hydrogen-containing layer, and the interlayer insulating film, And a fifth step of heat treatment.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to reduce reflection of the light which injected toward the photoelectric conversion part, the dangling bond in the light-receiving surface of a photoelectric conversion part can be reduced.

  A photoelectric conversion device 1 according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating a cross-sectional configuration of a photoelectric conversion apparatus 1 according to the first embodiment of the present invention.

  The photoelectric conversion device 1 includes a photoelectric conversion unit 201a, a multilayer wiring structure ML, a planarization film 220, a color filter 221, and a microlens 222.

  The photoelectric conversion unit 201a is formed as a region including a conductivity type (for example, N-type) impurity corresponding to a carrier (for example, an electron) in the semiconductor substrate 201. The photoelectric conversion unit 201a performs photoelectric conversion in a depletion layer formed between the semiconductor substrate 201 and a region of the opposite conductivity type (for example, P type), and accumulates the generated signal charges. The photoelectric conversion unit 201a has a light receiving surface 201a1. The semiconductor substrate 201 is made of, for example, silicon. The photoelectric conversion unit 201a is, for example, a photodiode.

  The charge generated in the photoelectric conversion unit 201a is transferred to the charge / voltage conversion unit 201b (see FIG. 3) at a predetermined timing by a transfer MOS transistor (not shown). The charge-voltage conversion unit 201b converts the transferred charge into a voltage. The charge-voltage conversion unit 201b is formed as a region containing a conductivity type (for example, N-type) impurity corresponding to carriers (for example, electrons) in the semiconductor substrate 201. The voltage of the charge-voltage conversion unit 201b is input to the gate of an amplification MOS transistor (not shown) through the contact plug 205 (see FIG. 3) and the first wiring layer 206 described later. As a result, the amplification MOS transistor outputs a signal corresponding to the voltage of the charge-voltage converter 201b to the column signal line (not shown) via the first wiring layer 206 and the like.

  The multilayer wiring structure ML includes a first interlayer insulating film 202, a first wiring layer 206, a via plug 210, a second interlayer insulating film 207, a second wiring layer 208, a via plug 215, a third interlayer insulating film 212, A third wiring layer 211, a hydrogen-containing layer 217, and a protective film 219 are included.

  The first interlayer insulating film 202 is disposed on the semiconductor substrate 201 so as to insulate the semiconductor substrate 201 and the first wiring layer 206. The first interlayer insulating film 202 fills the opening area OA. The first interlayer insulating film 202 is made of, for example, silicon oxide.

  The first wiring layer 206 is disposed on the first interlayer insulating film 202. The first wiring layer 206 defines the contour sides OAS1 and OAS2 in the opening area OA (see FIG. 2). For example, the first wiring layer 206 is formed of an intermetallic compound containing aluminum as a main component.

  The via plug 210 connects the first wiring layer 206 and the second wiring layer 208. The via plug 210 is made of, for example, an intermetallic compound containing tungsten as a main component.

  The second interlayer insulating film 207 is disposed between the first wiring layer 206 and the second wiring layer 208 so as to insulate them. The second interlayer insulating film 207 fills the opening area OA. The second interlayer insulating film 207 is made of, for example, silicon oxide.

  The second wiring layer 208 is disposed on the second interlayer insulating film 207. The second wiring layer 208 defines the contour sides OAS1 and OAS2 in the opening area OA (see FIG. 2). For example, the second wiring layer 208 is formed of an intermetallic compound containing aluminum as a main component.

  The via plug 215 connects the second wiring layer 208 and the third wiring layer 211. The via plug 215 is made of, for example, an intermetallic compound containing tungsten as a main component.

  The third interlayer insulating film 212 is disposed between the second wiring layer 208 and the third wiring layer 211 so as to insulate them. The third interlayer insulating film 212 fills the opening area OA. The third interlayer insulating film 212 is made of, for example, silicon oxide.

  The third wiring layer 211 is disposed on the third interlayer insulating film 212. The third wiring layer 211 is the uppermost wiring layer in the multilayer wiring structure ML. The third wiring layer 211 defines the contour sides OAS3 and OAS4 in the opening area OA (see FIG. 2). For example, the second wiring layer 208 is formed of an intermetallic compound containing aluminum as a main component.

  The hydrogen-containing layer 217 has the same pattern as the third wiring layer 211 and is completely overlapped with the third wiring layer 211 when viewed from the direction perpendicular to the light receiving surface 201a1. (See FIG. 2). The hydrogen-containing layer 217 contains hydrogen. The hydrogen-containing layer 217 is formed of silicon nitride containing hydrogen, for example.

  The protective film 219 extends so as to cover the third wiring layer 211, the hydrogen-containing layer 217, and the third interlayer insulating film 212. The hydrogen content of the protective film 219 can be made lower than the hydrogen content of the hydrogen-containing layer 217. The protective film 219 is made of, for example, silicon oxynitride.

  The planarization film 220 is disposed on the protective film 219 so as to provide a flat surface for the color filter 221.

  The color filter 221 is disposed on the planarization film 220. The color filter 221 selectively transmits light having a predetermined wavelength so that light having a predetermined wavelength in incident light enters the photoelectric conversion unit 201a.

  The microlens 222 refracts incident light so that the incident light is guided to the photoelectric conversion unit 201a.

  If the hydrogen content in the protective film 219 is higher than the hydrogen content in the hydrogen-containing layer 217, the difference between the refractive index of the protective film 219 and the refractive index of the third interlayer insulating film 212 is different from the hydrogen-containing layer 217. And the difference between the refractive index of the third interlayer insulating film 212 and the third interlayer insulating film 212.

  In contrast, in this embodiment, since the hydrogen-containing layer 217 for hydrogen termination is additionally provided, the hydrogen content in the protective film 219 can be made lower than the hydrogen content in the hydrogen-containing layer 217. . Accordingly, the difference between the refractive index of the protective film 219 and the refractive index of the third interlayer insulating film 212 is smaller than the difference between the refractive index of the hydrogen-containing layer 217 and the refractive index of the third interlayer insulating film 212. As a result, light reflection at the interface between the protective film 219 and the third interlayer insulating film 212 can be reduced.

  Further, since it is not necessary to consider light reflection in the hydrogen-containing layer 217, the hydrogen content can be increased, and dangling bonds on the light-receiving surface 201a1 of the photoelectric conversion portion 201a can be further reduced.

  Therefore, reflection of light incident on the photoelectric conversion unit can be reduced, and dangling bonds on the light receiving surface of the photoelectric conversion unit can be reduced.

  Next, the manufacturing method of the photoelectric conversion apparatus 1 is demonstrated using Fig.3 (a)-(i). 3A to 3I are process cross-sectional views illustrating a method for manufacturing the photoelectric conversion device 1. The cross sections shown in FIGS. 3A to 3I are different from the cross section shown in FIG. 1, and are the cross sections where the charge-voltage converter 201b is formed.

  In the process of FIG. 3A, by implanting conductivity type (for example, N-type) impurity ions corresponding to carriers into the semiconductor substrate 201, the photoelectric conversion unit 201a (see FIG. 1), the charge-voltage conversion unit 201b, Form. Then, a gate electrode (not shown) of the transfer MOS transistor is formed of polysilicon or the like between the photoelectric conversion unit 201a and the charge / voltage conversion unit 201b.

  Thereafter, a first interlayer insulating film 202 is formed on the semiconductor substrate 201 and the gate electrode by a CVD method. The upper surface of the first interlayer insulating film 202 is polished by a CMP (Chemical Mechanical Polishing) method. Then, a contact hole 203 is formed in the first interlayer insulating film 202 by a photolithography process and an etching process using a reactive ion etching method that follows. As a result, at least part of the surface of the charge-voltage converter 201b is exposed.

  In the step of FIG. 3B, blanket tungsten (hereinafter referred to as a W film) is grown by CVD so as to fill the contact hole 203 and cover the first interlayer insulating film 202. Here, the W film is formed of, for example, an intermetallic compound containing tungsten as a main component.

  In the step of FIG. 3C, the W film is polished by the CMP method. As a result, the portion of the W film excluding the contact hole 203 is removed, and the contact plug 205 is formed. At this time, polishing is performed to a level difference (about 1500 mm) or more between the contact plug 205 and other portions on the surface of the W film. This is because the amount of polishing by the CMP method is not uniform within the surface of the semiconductor substrate 201, so that it is necessary to partially polish excessively.

  In the step of FIG. 3D, a metal film is formed on the polished surface in the step of FIG. 3C, that is, on the first interlayer insulating film 202, uniformly in the surface by the PVD method. The metal film is formed of, for example, an intermetallic compound containing aluminum as a main component. Then, the metal film is patterned by a photolithography process and an etching process to form a first wiring layer 206.

  Then, a second interlayer insulating film 207 is formed by a CVD method so as to cover the first interlayer insulating film 202 and the first wiring layer 206. The upper surface of the second interlayer insulating film 207 is polished by a CMP (Chemical Mechanical Polishing) method. Then, a via hole 228 is formed in the second interlayer insulating film 207 by a photolithography process and a subsequent etching process using a reactive ion etching method. Thereby, at least a part of the surface of the first wiring layer 206 is exposed.

  In the step shown in FIG. 3E, a W film is grown by CVD so as to fill the via hole 228 and cover the second interlayer insulating film 207. Here, the W film is formed of, for example, an intermetallic compound containing tungsten as a main component. The growth conditions at this time are the same as those in the step of FIG.

  In the step of FIG. 3F, the W film is polished by the CMP method. Thereby, the portion of the W film excluding the via hole 228 is removed, and the via plug 210 is formed. At this time, the surface of the W film is polished to a level difference (about 1500 mm) between the via plug 210 and other portions. This is because the amount of polishing by the CMP method is not uniform within the surface of the semiconductor substrate 201, so that it is necessary to partially polish excessively.

  In the step of FIG. 3G, a metal film is uniformly formed on the polished surface by the step of FIG. 3F, that is, on the second interlayer insulating film 207 by the PVD method. The metal film is formed of, for example, an intermetallic compound containing aluminum as a main component. Then, the metal film is patterned by a photolithography process and an etching process to form a second wiring layer 208.

  Then, a third interlayer insulating film 212 is formed by a CVD method so as to cover the second interlayer insulating film 207 and the second wiring layer 208. The upper surface of the third interlayer insulating film 212 is polished by the CMP method. Then, a via hole 213 is formed in the third interlayer insulating film 212 by a photolithography process and an etching process using a reactive ion etching method that follows. Thereby, at least a part of the surface of the second wiring layer 208 is exposed.

  In the step of FIG. 3H, a W film is grown by CVD so as to fill the via hole 213 and cover the third interlayer insulating film 212. Here, the W film is formed of, for example, an intermetallic compound containing tungsten as a main component. The growth conditions at this time are the same as those in the step of FIG.

  In the step of FIG. 3I, the W film is polished by the CMP method. Thereby, the portion of the W film excluding the via hole 213 is removed, and the via plug 215 is formed. At this time, the surface of the W film is polished to a level difference (about 1500 mm) or more between the via plug 215 and other portions. This is because the amount of polishing by the CMP method is not uniform within the surface of the semiconductor substrate 201, so that it is necessary to partially polish excessively.

  In the step of FIG. 3 (j), first (first step), on the polished surface by the step of FIG. 3 (i), that is, on the third interlayer insulating film 212, in-plane uniform by PVD method. Then, a metal film is formed. The metal film is formed of, for example, an intermetallic compound containing aluminum as a main component.

Further (second step), a dielectric film containing hydrogen is formed on the metal film. Here, a silicon nitride film is formed as a dielectric film using a plasma CVD method. The formation conditions at this time are a substrate temperature of 400 ° C., RF Power of 560 W, a processing gas of SiH 4 / N ₂ / NH _3, and a flow rate of each gas of 215/3000/70 cc / min. The formed silicon nitride film has a refractive index of 2.0.

  Then (third step), the metal film and the dielectric film (silicon nitride film) are patterned by a photolithography process and an etching process using the same mask pattern.

In the etching process, processing is performed in two steps (first step and second step). In the first step, RIE processing is performed while supplying Ar / CHF ₃ / CF ₄ gas at a flow rate of 700/30/25 sccm with RF Power 1000W. In the second step, the RIE process is performed while supplying Cl ₂ / BCl / CHF ₃ gas at a flow rate of 700/30/25 sccm with DC Power 150W.

  The metal film is etched by the first step to form the hydrogen-containing layer 217, and the dielectric film is etched by the second step to form the third wiring layer 211. That is, the process in the first step and the process in the second step are continuously performed using one mask pattern. Thereby, the hydrogen-containing layer 217 has the same pattern as the third wiring layer 211 and completely overlaps the third wiring layer 211 when viewed from the direction perpendicular to the light receiving surface 201a1.

In the step of FIG. 3K, first (fourth step), the hydrogen content is lower than that of the hydrogen-containing layer 217 so as to cover the third wiring layer 211, the hydrogen-containing layer 217, and the interlayer insulating film 212. A protective film 219 is formed. The formation conditions at this time are as follows: the substrate temperature is 400 ° C., the RF power is 535 W, the processing gas is SiH ₄ / N ₂ / NH ₃ / N ₂ O gas, and the flow rates of the respective gases are 85/3000/70/130 cc / min, respectively. To do. The refractive index of the formed protective film (silicon oxynitride film) 219 is, for example, 1.60.

  Thereafter (fifth step), heat treatment is performed. By this heat treatment, etching damage of the light receiving surface 201a1 of the photoelectric conversion unit 201a due to the etching process for forming the third wiring layer 211 and the hydrogen-containing layer 217 is removed. More specifically, hydrogen is supplied (diffused) from the hydrogen-containing layer 217 to the light receiving surface 201a1 of the photoelectric conversion unit 201a by this heat treatment, so that dangling bonds on the light receiving surface 201a1 are reduced. At this time, the heat treatment condition is 450 ° C. in a nitrogen atmosphere.

  Next, a planarizing film 220 is formed on the protective film 219 by applying a material similar to the color filter 221 on the protective film 219. Thereafter, a color filter 221 is formed on the planarizing film 220.

  The refractive indexes of the color filter 221 and the planarizing film 220 are 1.60, which is the same as that of the protective film (silicon oxynitride film) 219. The color filter 221 is formed so that the three primary colors of red, green, and blue are located above the respective photoelectric conversion units 201a. The light that has passed through the color filter 221 (light that has been selectively dispersed to a wavelength indicating each color sensitivity) repeats reflection and transmission, and reaches the light receiving surface 201a1 of each photoelectric conversion unit 201a.

  Further, a micro lens 222 is formed on the color filter 221.

  Thus, in the present embodiment, the third wiring layer 211 and the hydrogen-containing layer 217 are patterned using the same mask. Thus, the hydrogen-containing layer 217 has the same pattern as the third wiring layer 211 and is completely overlapped with the third wiring layer 211 when viewed from the direction perpendicular to the light receiving surface 201a1. Easy. Further, there is no misalignment between the third wiring layer 211 and the hydrogen-containing layer 217. Furthermore, the surface formed by the side surface 211a that defines the contour side OAS3 in the third wiring layer and the side surface 217a of the hydrogen-containing layer 217 is continuous. As a result, as shown in FIG. 1, the light PB incident on a region closer to the normal line PL passing through the center of the light receiving surface 201 a 1 than the third wiring layer 211 is not easily reflected by the hydrogen-containing layer 217. That is, it has a structure that is advantageous for increasing the light collection efficiency on the light receiving surface 201a1 of the photoelectric conversion unit 201a.

  In addition, since the difference in refractive index between the color filter 221, the planarization film 220, and the protective film 219 is small, there is almost no reflection at the interface between them. Further, the difference between the refractive index of the protective film 219 and the refractive index of the third interlayer insulating film 212 is smaller than the difference between the refractive index of the hydrogen-containing layer 217 and the refractive index of the third interlayer insulating film 212. Thereby, reflection at the interface between the protective film 219 and the third interlayer insulating film 212 is also suppressed. Thereby, since reflection of the light PB incident toward the photoelectric conversion unit 201a can be reduced, the photosensitivity of the photoelectric conversion device 1 can be increased. Note that a sixth step of heat treatment may be provided after the first step and the second step in the step of FIG. 3J and before the third step. In this case, by applying heat treatment in a state where a dielectric film (silicon nitride film) containing hydrogen exists on the entire surface above the photoelectric conversion unit 201a, dangling bonds on the light receiving surface 201a1 of the photoelectric conversion unit 201a are easily hydrogenated. Can be terminated with That is, a photoelectric conversion device in which dark current is further reduced can be realized by a two-step heat treatment of the sixth step before the third step and the fifth step after the fourth step. Here, the heat treatment conditions in the sixth step are the same as the heat treatment conditions in the fourth step.

  Next, an example of an imaging system to which the photoelectric conversion device of the present invention is applied is shown in FIG.

  As shown in FIG. 4, the imaging system 90 mainly includes an optical system, an imaging device 86, and a signal processing unit. The optical system mainly includes a shutter 91, a photographing lens 92, and a diaphragm 93. The imaging device 86 includes the photoelectric conversion device 1. The signal processing unit mainly includes an imaging signal processing circuit 95, an A / D converter 96, an image signal processing unit 97, a memory unit 87, an external I / F unit 89, a timing generation unit 98, an overall control / calculation unit 99, and a recording. A medium 88 and a recording medium control I / F unit 94 are provided. The signal processing unit may not include the recording medium 88.

  The shutter 91 is provided in front of the photographic lens 92 on the optical path and controls exposure.

  The photographing lens 92 refracts incident light to form an image of a subject on the imaging surface of the photoelectric conversion device 1 of the imaging device 86.

  The diaphragm 93 is provided between the photographing lens 92 and the photoelectric conversion device 1 on the optical path, and adjusts the amount of light guided to the photoelectric conversion device 1 after passing through the photographing lens 92.

  The photoelectric conversion device 1 of the imaging device 86 converts an image of a subject formed on the imaging surface of the photoelectric conversion device 1 into an image signal. The imaging device 86 reads the image signal from the photoelectric conversion device 1 and outputs it.

  The imaging signal processing circuit 95 is connected to the imaging device 86 and processes the image signal output from the imaging device 86.

  The A / D converter 96 is connected to the imaging signal processing circuit 95 and converts the processed image signal (analog signal) output from the imaging signal processing circuit 95 into a digital signal.

  The image signal processing unit 97 is connected to the A / D converter 96, and performs various kinds of arithmetic processing such as correction on the image signal (digital signal) output from the A / D converter 96 to generate image data. To do. The image data is supplied to the memory unit 87, the external I / F unit 89, the overall control / calculation unit 99, the recording medium control I / F unit 94, and the like.

  The memory unit 87 is connected to the image signal processing unit 97 and stores the image data output from the image signal processing unit 97.

  The external I / F unit 89 is connected to the image signal processing unit 97. Thus, the image data output from the image signal processing unit 97 is transferred to an external device (such as a personal computer) via the external I / F unit 89.

  The timing generation unit 98 is connected to the imaging device 86, the imaging signal processing circuit 95, the A / D converter 96, and the image signal processing unit 97. Thereby, a timing signal is supplied to the imaging device 86, the imaging signal processing circuit 95, the A / D converter 96, and the image signal processing unit 97. The imaging device 86, the imaging signal processing circuit 95, the A / D converter 96, and the image signal processing unit 97 operate in synchronization with the timing signal.

  The overall control / arithmetic unit 99 is connected to the timing generation unit 98, the image signal processing unit 97, and the recording medium control I / F unit 94, and the timing generation unit 98, the image signal processing unit 97, and the recording medium control I / F. The unit 94 is controlled as a whole.

  The recording medium 88 is detachably connected to the recording medium control I / F unit 94. As a result, the image data output from the image signal processing unit 97 is recorded on the recording medium 88 via the recording medium control I / F unit 94.

  With the above configuration, if a good image signal is obtained in the photoelectric conversion device 1, a good image (image data) can be obtained.

  A photoelectric conversion apparatus 300 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram illustrating a cross-sectional configuration of a photoelectric conversion apparatus 300 according to the second embodiment of the present invention. Below, it demonstrates centering on a different part from 1st Embodiment, and abbreviate | omits description of the same part.

  The photoelectric conversion device 300 differs from the first embodiment in that it includes a multilayer wiring structure ML300. The multilayer wiring structure ML300 further includes a hydrogen-containing layer (another hydrogen-containing layer) 316 and a hydrogen-containing layer (another hydrogen-containing layer) 318.

  The hydrogen-containing layer 316 has the same pattern as the first wiring layer (other wiring layer) 206 and is completely overlapped with the first wiring layer 206 when viewed from a direction perpendicular to the light receiving surface 201a1. The first wiring layer 206 is disposed on the first wiring layer 206. The hydrogen-containing layer 316 contains hydrogen. The hydrogen content in the hydrogen-containing layer 316 is higher than the hydrogen content in the protective film 219. The hydrogen-containing layer 316 is formed of, for example, silicon nitride containing hydrogen.

  The hydrogen-containing layer 318 has the same pattern as the second wiring layer (other wiring layers) 208 and is completely overlapped with the second wiring layer 208 when viewed from a direction perpendicular to the light receiving surface 201a1. It is disposed on the second wiring layer 208. The hydrogen-containing layer 318 includes hydrogen. The hydrogen content in the hydrogen-containing layer 318 is higher than the hydrogen content in the protective film 219. The hydrogen-containing layer 318 is made of, for example, silicon nitride containing hydrogen.

  Thus, since the hydrogen-containing layer is disposed on each wiring layer, dangling bonds on the light receiving surface 201a1 of the photoelectric conversion unit 201a can be easily reduced.

  Moreover, the manufacturing method of the photoelectric conversion apparatus 300 differs from 1st Embodiment by the following points, as shown in FIG. FIG. 6 is a process cross-sectional view illustrating a method for manufacturing the photoelectric conversion device 300.

  In the process of FIG. 6D1, processing different from the process of FIG. 3D is performed in the following points.

  After forming the metal film, a dielectric film containing hydrogen is formed on the metal film. The formation conditions at this time are the same as those in the first step and the second step in the step of FIG.

  Then, the metal film and the dielectric film (silicon nitride film) are patterned by the photolithography process and the etching process using the same mask pattern. The formation conditions at this time are the same as those in the third step in the step of FIG. As a result, the first wiring layer 206 has the same pattern as the first wiring layer 206 and is completely overlapped with the first wiring layer 206 when viewed from a direction perpendicular to the light receiving surface 201a1. A hydrogen-containing layer 316 disposed on one wiring layer 206 is formed.

  Then, a second interlayer insulating film 207 is formed by a CVD method so as to cover the first interlayer insulating film 202, the first wiring layer 206, and the hydrogen-containing layer 316.

The etching conditions for forming the via hole 228 in the second interlayer insulating film 207 are RF Power 2000W, the processing gas is C ₄ F ₈ / O ₂ / Ar, and the flow rate of each gas is 20/20/800 sccm. It is. As a result, the hydrogen-containing layer 316 is eliminated from the via hole 228, and at least a part of the surface of the first wiring layer 206 is exposed.

  In the process shown in FIG. 6G1, processing different from that shown in FIG. 3G is performed in the following points.

  After forming the metal film, a dielectric film containing hydrogen is formed on the metal film. The formation conditions at this time are the same as those in the first step and the second step in the step of FIG.

  Then, the metal film and the dielectric film (silicon nitride film) are patterned by the photolithography process and the etching process using the same mask pattern. The formation conditions at this time are the same as those in the third step in the step of FIG. Thus, the second wiring layer 208 has the same pattern as the second wiring layer 208 and is completely overlapped with the second wiring layer 208 when viewed from a direction perpendicular to the light receiving surface 201a1. And a hydrogen-containing layer 318 disposed on the second wiring layer 208.

  Then, a third interlayer insulating film 212 is formed by a CVD method so as to cover the second interlayer insulating film 207, the second wiring layer 208, and the hydrogen-containing layer 318.

The etching conditions for forming the via hole 213 in the third interlayer insulating film 212 are RF Power 2000W, the processing gas is C ₄ F ₈ / O ₂ / Ar, and the flow rate of each gas is 20/20/800 sccm. It is. As a result, at least a part of the surface of the second wiring layer 208 is exposed such that the hydrogen-containing layer 318 is eliminated from the via hole 213.

  Thus, in the present embodiment, the first wiring layer 206 and the hydrogen-containing layer 316 are patterned using the same mask. As a result, the hydrogen-containing layer 316 has the same pattern as the first wiring layer 206 and is completely overlapped with the first wiring layer 206 when viewed from the direction perpendicular to the light receiving surface 201a1. Easy. Further, there is no misalignment between the first wiring layer 206 and the hydrogen-containing layer 316. Furthermore, the surface formed by the side surface defining the contour side OAS1 (see FIG. 2) in the first wiring layer and the side surface of the hydrogen-containing layer 316 is continuous. As a result, light incident on a region closer to the first wiring layer 206 with respect to the normal line PL (see FIG. 1) passing through the center of the light receiving surface 201a1 is not easily reflected by the hydrogen-containing layer 316. That is, it has a structure that is advantageous for increasing the light collection efficiency on the light receiving surface 201a1 of the photoelectric conversion unit 201a.

  Similarly, in the present embodiment, the second wiring layer 208 and the hydrogen-containing layer 318 are patterned using the same mask. Thus, the hydrogen-containing layer 318 has the same pattern as the second wiring layer 208 and is completely overlapped with the second wiring layer 208 when viewed from the direction perpendicular to the light receiving surface 201a1. Easy. Further, there is no misalignment between the second wiring layer 208 and the hydrogen-containing layer 318. Further, the surface formed by the side surface defining the contour side OAS1 (see FIG. 2) in the second wiring layer and the side surface of the hydrogen-containing layer 318 is continuous. As a result, light incident on a region closer to the second wiring layer 208 with respect to the normal line PL (see FIG. 1) passing through the center of the light receiving surface 201a1 is not easily reflected by the hydrogen-containing layer 318. That is, it has a structure that is advantageous for increasing the light collection efficiency on the light receiving surface 201a1 of the photoelectric conversion unit 201a.

The figure which shows the cross-sectional structure of the photoelectric conversion apparatus 1 which concerns on 1st Embodiment of this invention. The figure which shows the opening area | region in the photoelectric conversion apparatus 1. FIG. 5 is a process cross-sectional view illustrating a method for manufacturing the photoelectric conversion device 1. 1 is a configuration diagram of an imaging system to which a photoelectric conversion device according to a first embodiment is applied. The figure which shows the cross-sectional structure of the photoelectric conversion apparatus 300 which concerns on 2nd Embodiment of this invention. 4 is a process cross-sectional view illustrating a method for manufacturing the photoelectric conversion device 300. FIG.

Explanation of symbols

1,300 Photoelectric conversion device 90 Imaging system

Claims (8)

A photoelectric conversion unit having a light receiving surface;
A multilayer wiring structure defining an opening region above the photoelectric conversion unit;
With
The multilayer wiring structure is
An uppermost wiring layer that defines a contour side in the opening region;
It has the same pattern as the uppermost wiring layer and is disposed on the uppermost wiring layer so as to completely overlap the uppermost wiring layer when viewed from a direction perpendicular to the light receiving surface, and contains hydrogen. A hydrogen-containing layer;
An interlayer insulating film filling at least the opening region;
A protective film that extends to cover the uppermost wiring layer, the hydrogen-containing layer, and the interlayer insulating film, and has a lower hydrogen content than the hydrogen-containing layer;
A photoelectric conversion device comprising: The photoelectric conversion device according to claim 1, wherein the uppermost wiring layer contains aluminum as a main component. The difference between the refractive index of the protective film and the refractive index of the interlayer insulating film is smaller than the difference between the refractive index of the hydrogen-containing layer and the refractive index of the interlayer insulating film. The photoelectric conversion device described. The multilayer wiring structure is
Other wiring layers defining other contour sides in the opening region,
It has the same pattern as the other wiring layer and is arranged on the other wiring layer so as to completely overlap the other wiring layer when viewed from a direction perpendicular to the light receiving surface, and contains hydrogen. With other hydrogen-containing layers,
The photoelectric conversion device according to claim 1, further comprising: 5. The photoelectric conversion device according to claim 4, wherein a surface formed by a side surface defining the other contour side in the other wiring layer and a side surface of the other hydrogen-containing layer is continuous. The photoelectric conversion device according to any one of claims 1 to 5,
An optical system that forms an image on the imaging surface of the photoelectric conversion device;
A signal processing unit that processes the signal output from the photoelectric conversion device to generate image data;
An imaging system comprising: A method for manufacturing a photoelectric conversion device having a photoelectric conversion part having a light receiving surface and an interlayer insulating film above the photoelectric conversion part,
A first step of forming a metal film on the interlayer insulating film;
A second step of forming a dielectric film containing hydrogen on the metal film;
Patterning the metal film using a single mask pattern to form an uppermost wiring layer that defines a contour side in an opening region above the photoelectric conversion unit; and patterning the dielectric film Thus, hydrogen having the same pattern as the uppermost wiring layer and disposed on the uppermost wiring layer so as to completely overlap the uppermost wiring layer when viewed from a direction perpendicular to the light receiving surface. Forming the inclusion layer continuously, a third step,
A fourth step of forming a protective film having a lower hydrogen content than the hydrogen-containing layer so as to cover the uppermost wiring layer, the hydrogen-containing layer, and the interlayer insulating film;
A fifth step of heat treatment after the fourth step;
A method for manufacturing a photoelectric conversion device, comprising: The photoelectric conversion device according to claim 7, further comprising a sixth step of performing a heat treatment after the first step and the second step and before the third step. Production method.

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