WO2012111047A1 - Solid-state image pickup device - Google Patents

Solid-state image pickup device Download PDF

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Publication number
WO2012111047A1
WO2012111047A1 PCT/JP2011/003605 JP2011003605W WO2012111047A1 WO 2012111047 A1 WO2012111047 A1 WO 2012111047A1 JP 2011003605 W JP2011003605 W JP 2011003605W WO 2012111047 A1 WO2012111047 A1 WO 2012111047A1
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Prior art keywords
film
insulating film
solid
light
imaging device
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PCT/JP2011/003605
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French (fr)
Japanese (ja)
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敦生 中川
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パナソニック株式会社
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/14625—Optical elements or arrangements associated with the device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/1462—Coatings
    • H01L27/14623—Optical shielding

Definitions

  • the present invention relates to a solid-state imaging device, and more particularly to a configuration of an insulating film covering a light shielding film on a transfer electrode.
  • n-type semiconductor region photoelectric conversion region
  • p-type semiconductor substrate silicon substrate
  • a signal is generated in the n-type semiconductor region according to the amount of incident light. Charge is generated.
  • a video signal can be obtained from the signal charges generated in each pixel.
  • FIG. 9 is a cross-sectional view showing an example of a conventional solid-state imaging device represented by Patent Document 1 or Patent Document 2, and shows a range including one of the pixels arranged on the semiconductor substrate 901.
  • a light receiving portion 902 made of a photodiode is provided for each pixel on a surface layer portion of a semiconductor substrate 901, and a light receiving portion is formed on the surface layer portion of the semiconductor substrate 901 and adjacent to the light receiving portion 902.
  • a transfer region 903 for transferring charges generated by photoelectric conversion at 902 is formed.
  • a silicon oxide film 905 is provided on the semiconductor substrate 901, and a transfer electrode 904 is provided on the silicon oxide film 905 and at a position corresponding to the upper portion of the transfer region 903.
  • a light shielding film 907 having an opening above the light receiving portion 902 is provided on the transfer electrode 904 via a PSG (Phosphorus silicate glass) film 906.
  • the light shielding film 907 is made of a metal such as aluminum or tungsten, and reflects and absorbs stray light that has not entered the light receiving portion 902, so that the stray light directly enters the charge transfer region 903 and generates a false signal called smear. Prevent it from occurring.
  • a plasma silicon nitride film 908 is provided on the light shielding film 907.
  • This plasma silicon nitride film 908 is formed by using the plasma CVD method and then annealed. By this annealing, hydrogen contained in the plasma silicon nitride film 908 is desorbed, and dangling on the surface of the semiconductor substrate 901 is performed. By terminating the bond, the interface state can be lowered and the dark current can be reduced.
  • the plasma silicon nitride film 908 is smaller than 0.75 which is the composition ratio of silicon to nitrogen in the stoichiometrically stable composition ratio Si 3 N 4 , that is, nitrogen-rich.
  • sufficient hydrogen can be supplied to increase the number of NH bonds desorbed during annealing and terminate dangling bonds on the surface of the semiconductor substrate 901.
  • the refractive index of the plasma silicon nitride film 908 decreases as it becomes richer in nitrogen, light incident on the light receiving portion 902 from above is not refracted obliquely near the edge of the light shielding film 907, and is inclined. It is suggested that a false signal, that is, a so-called smear, which is generated when light enters the charge transfer region 903 directly by multiple reflection between the light shielding film 907 and the semiconductor substrate 901 can be prevented.
  • a silicon oxide film 909 as an interlayer insulating film is deposited on the plasma silicon nitride film 908.
  • the light shielding film 907 even if a metal film such as tungsten or aluminum is used for the light shielding film 907, the light incident on the surface (metal surface) of the light shielding film 907 is not completely reflected. However, a part of the light is absorbed by the light shielding film 907 and the sensitivity of the solid-state imaging device is lowered.
  • the refractive index of the plasma silicon nitride film 908 covering the light shielding film 907 is more than the refractive index of the silicon oxide film 909 (interlayer insulating film) covering it. Therefore, the light incident on the solid-state imaging device is refracted toward the plasma silicon nitride film 908 having a high refractive index and hits the light shielding film 907 provided under the plasma silicon nitride film 908, thereby causing such a problem. appear.
  • the refractive index of the plasma silicon nitride film 908 decreases with increasing nitrogen richness.
  • the composition ratio of the plasma silicon nitride film 908 is changed to increase the nitrogen richness.
  • the refractive index is described to be about 1.8, and the above problem cannot be solved.
  • the refractive index of a silicon oxide film 909 generally used as an interlayer insulating film in a solid-state imaging device is about 1.45, the refractive index (1.
  • the refractive index of the film such as the silicon oxide film 908 covering the silicon oxide film 908 is much higher.
  • the present invention has been made in view of the above problems, and suppresses a decrease in sensitivity even in a configuration in which a film having a refractive index higher than that of a silicon oxide film is formed on a light shielding film in order to reduce dark current.
  • An object of the present invention is to provide a solid-state imaging device that can be used.
  • the solid-state imaging device includes a semiconductor substrate, a transfer electrode, a light shielding film, a first insulating film, and a second insulating film.
  • a photoelectric conversion region for photoelectrically converting incident light into charges and a transfer region for transferring the generated charges are provided adjacent to each other on one main surface side.
  • the transfer electrode is provided on the semiconductor substrate and in a region corresponding to the transfer region.
  • the light shielding film covers the upper area of the transfer area and has an opening corresponding to the upper area of the photoelectric conversion area.
  • the first insulating film is formed on the light shielding film.
  • the second insulating film is formed on the first insulating film.
  • the second insulating film is a film containing hydrogen, and the refractive index of the first insulating film is lower than the refractive index of the second insulating film.
  • a solid-state imaging device includes a semiconductor substrate, a transfer electrode, a light shielding film, a first insulating film, a second insulating film, and a third insulating film.
  • a photoelectric conversion region for photoelectrically converting incident light into charges and a transfer region for transferring the generated charges are provided adjacent to each other on one main surface side.
  • the transfer electrode is provided on the semiconductor substrate and in a region corresponding to the transfer region.
  • the light shielding film covers the upper area of the transfer area and has an opening corresponding to the upper area of the photoelectric conversion area.
  • the first insulating film is formed on the light shielding film.
  • the second insulating film is formed on the first insulating film.
  • the third insulating film is formed on the second insulating film.
  • the first insulating film is a film containing hydrogen, and the refractive index of the second insulating film is lower than the refractive index of the third insulating film.
  • the hydrogen contained in the second insulating film containing hydrogen is desorbed by annealing and terminates dangling bonds on the surface of the semiconductor substrate. It is possible to reduce the interface state and to reduce the dark current.
  • the first insulating film having a refractive index lower than that of the second insulating film is interposed between the light shielding film and the second insulating film, whereby the interface between the first insulating film and the second insulating film.
  • the reflectance of the light propagating in the direction of the light shielding film is improved, and the light incident on the solid-state imaging device is prevented from reaching the light shielding film and being partially absorbed by the light shielding film.
  • the sensitivity of the solid-state imaging device can be improved.
  • the solid-state imaging device of the present invention according to (2) above, hydrogen contained in the first insulating film containing hydrogen is desorbed by annealing, and dangling bonds on the surface of the semiconductor substrate are terminated.
  • the interface state of the transfer region can be lowered and the dark current can be reduced.
  • the light since light propagating in the direction of the light shielding film is totally reflected at the interface between the second insulating film and the third insulating film, the light can be reflected in the direction of the photoelectric conversion region. Thereby, absorption of the light by a light shielding film can be suppressed and the sensitivity of a solid-state imaging device can be improved.
  • the insulating film having a higher refractive index than the silicon oxide film is formed on the light shielding film in order to reduce the dark current.
  • the amount of light that reaches the light shielding film surface and is absorbed is reduced, light absorption by the light shielding film is reduced, and a lot of light can be guided to the light receiving part by reflecting the light in the direction of the light receiving part, Sensitivity decline is suppressed.
  • the following variation configuration can be adopted as an example.
  • the first insulating film can be opened at a portion corresponding to the upper part of the photoelectric conversion region.
  • the second insulating film may be a silicon nitride film formed using a plasma CVD method.
  • the solid-state imaging device of the present invention according to the above (1) can be configured such that the first insulating film is a silicon oxide film.
  • the thickness of the first insulating film is 120 [nm] to 220 [nm]
  • the thickness of the second insulating film is 80 [nm]. It can be configured to be 130 nm.
  • the second insulating film can be configured to be opened at a portion corresponding to the upper part of the photoelectric conversion region.
  • the first insulating film may be a silicon nitride film formed using a plasma CVD method.
  • the second insulating film can be a silicon oxide film and the third insulating film can be a silicon nitride film.
  • FIG. 1 is a block diagram schematically showing an overall configuration of a solid-state imaging device 1 according to Embodiment 1 of the present invention.
  • 2 is a cross-sectional view schematically showing a configuration of a pixel region 10 in the solid-state imaging device 1.
  • FIG. (A) is a conceptual diagram which shows reflection of the light ray in the light shielding film in the solid-state imaging device which concerns on an Example, and the film structure of the upper part
  • (b) is the light-shielding film in the solid-state imaging device which concerns on a comparative example
  • a plurality of pixels 100 are arranged in a matrix in the XY plane direction.
  • a vertical CCD unit 21 extending in the Y-axis direction is provided between the rows, and a horizontal CCD unit 22 extending in the X-axis direction is provided at the lower end of the vertical CCD unit 21 in the Y-axis direction. It has been.
  • a region including the plurality of pixels 100 and the vertical CCD unit 21 is a pixel region 10.
  • An output amplifier unit 23 is connected to the horizontal CCD unit 22.
  • FIG. 2 shows a cross-sectional view including one pixel 100 of the solid-state imaging device 1.
  • the parts 103 are arranged alternately.
  • a transfer electrode 104 is provided above the charge transfer unit 103 with a silicon oxide film 105 (hereinafter referred to as “first silicon oxide film” for distinction) 105 interposed therebetween.
  • the light 110 incident on the solid-state imaging device 1 is photoelectrically converted into charges by the light receiving unit 102, and the charges are transferred in the area of the charge transfer unit 103.
  • a silicon oxide film (hereinafter referred to as a “second silicon oxide film” 106) is provided on the first silicon oxide film 105 and the transfer electrode 104.
  • the light shielding film 107 has an opening corresponding to the upper part of the light receiving unit 102.
  • An insulating film 108 is provided on the light shielding film 107, and a hydrogen-containing film 109 is provided on the insulating film 108.
  • the refractive index of the insulating film 108 is lower than the refractive index of the hydrogen-containing film 109.
  • a silicon nitride film as the hydrogen-containing film 109 is formed using, for example, a plasma CVD method, and then annealed, whereby hydrogen contained in the film is desorbed, and dangling bonds on the surface of the semiconductor substrate 101 are terminated. Fulfills the function of As a result, the interface state of the semiconductor substrate 101 is lowered, and the dark current can be reduced.
  • the refractive index of the hydrogen-containing film 109 made of a silicon nitride film formed by the plasma CVD method is about 1.9 although it depends on the composition ratio of silicon and nitrogen.
  • an interlayer insulating film made of a silicon oxide film is generally formed on the hydrogen-containing film 109, which is a silicon nitride film (not shown).
  • the refractive index of this silicon oxide film is about 1. 45.
  • the refractive index of the silicon nitride film is higher than the refractive index of the interlayer insulating film of the silicon oxide film formed thereon, and the light incident on the solid-state imaging device 1 enters the silicon nitride film having a high refractive index. Propagated toward the light shielding film in the lower part thereof.
  • the insulating film 108 made of a material having a lower refractive index than that of the silicon nitride film is provided between the silicon nitride film that is the hydrogen-containing film 109 and the light-shielding film 107, so that the hydrogen-containing film 109
  • the reflectance of light propagating in the direction of the light shielding film 107 at the interface between the film 109 and the insulating film 108 is improved, and the light incident on the solid-state imaging device 1 reaches the light shielding film 107 as indicated by a light beam 110 in FIG.
  • the insulating film 108 made of a material having a refractive index lower than that of the silicon nitride film is present in the portion where the light shielding film 107 is opened (the portion corresponding to the upper portion of the light receiving portion 102). Then, if the insulating film 108 is removed and the hydrogen-containing film 109 is provided, the refractive index of the medium in this portion can be increased, and the sensitivity of the solid-state imaging device 1 can be improved.
  • FIG. 3A shows a simulation structure of the solid-state imaging device according to the embodiment.
  • the flat film 202 made of the first silicon oxide film is formed on the flat film 201 made of tungsten (W) having a sufficiently thick film thickness so that it can be considered that there is no back surface reflection.
  • a flat film 203 made of a plasma silicon nitride film, and a flat film 204 made of a second silicon oxide film is further formed thereon.
  • FIG. 3B shows a simulation structure of the solid-state imaging device according to the comparative example.
  • a plasma silicon nitride film 952 is provided on the light shielding film 951, and a silicon oxide film 953 is provided thereon.
  • a characteristic matrix method which is general for light interference calculation in a thin film was used.
  • the average value of the P-polarized light and the S-polarized light was obtained as the reflectance.
  • FIG. 4 shows the simulation result.
  • the thickness of the flat film 202 is set to 100 [nm]
  • the thickness of the flat film 203 is set to 100 [nm].
  • a plasma silicon nitride film 952 is provided on the light shielding film 951 and the silicon oxide film is formed thereon, as in the structure according to the prior art shown in FIG. 953 is provided.
  • incident light 954 is reflected at the interface between the silicon oxide film 953 and the plasma silicon nitride film 952 and at the interface between the plasma silicon nitride film 952 and the light shielding film 951, but some of the light is reflected in the plasma silicon nitride film.
  • the light is not reflected at the interface between 952 and the light shielding film 951 but is absorbed by the light shielding film 951.
  • the first film is formed between the flat film (light-shielding film) 201 made of tungsten (W) and the flat film 203 made of plasma silicon nitride film.
  • the flat film 202 which is a silicon oxide film
  • the flat film (light-shielding film) 201 is reached by the amount of reflection at the interface between the flat film 203 and the flat film 202 as compared with the structure according to the comparative example. It is considered that the amount of light absorbed can be reduced and the reflectance can be increased.
  • a silicon oxide film is provided between the flat film 201 that is a light shielding film and the flat film 203 that is a plasma silicon nitride film as in the configuration according to the embodiment.
  • the flat film 202 see FIG. 3A
  • the flat film is compared with the structure according to the comparative example (see FIG. 3B) in which there is no flat film 202 that is a silicon oxide film therebetween.
  • the reflectance of the light 205 toward the 201 can be increased, the light absorption by the flat film 201 can be suppressed, more light can be reflected toward the light receiving unit, and the sensitivity reduction of the solid-state imaging device can be suppressed. It is thought that it shows.
  • the reflectance when the film thicknesses of the flat film 202 as the first silicon oxide film and the flat film 203 as the plasma silicon nitride film are changed.
  • the film thickness dependence was calculated using simulation. The simulation results are shown in FIGS.
  • the incident angle ⁇ 60 [°]
  • ⁇ 70 [°]
  • ⁇ 80 [°].
  • the reflectance was calculated by changing the thickness of the flat film 202 as the first silicon oxide film and the flat film 203 as the plasma silicon nitride film.
  • the condition for the highest reflectivity is to block the light incident on the solid-state imaging device. This is when the incident angle ⁇ toward the film is about 70 [°].
  • the film thickness range suitable for obtaining a high reflectance is that the film thickness of the flat film 202 as the first silicon oxide film is 120 [nm]. It can be seen that the thickness of the flat film 203 that is a plasma silicon nitride film is in the range of 80 [nm] to 130 [nm].
  • the film thickness in such a range, 50% or more of the light 110 incident on the light shielding film 107 in the solid-state imaging device 1 according to the present embodiment shown in FIG. Can be reflected in the direction of the light receiving unit 102.
  • the sensitivity of the solid-state imaging device 1 can be improved by 4% or more compared to the configuration of the solid-state imaging device according to the related art.
  • the incident light 110 is suppressed from being absorbed by the light shielding film 107, and more light 110 is reflected in the direction of the light receiving unit 102. As a result, a decrease in sensitivity can be suppressed.
  • Embodiment 2 a solid-state imaging device according to Embodiment 2 of the present invention will be described with reference to a cross-sectional view of the main part of FIG.
  • the light receiving unit 302 and the charge transfer unit 303 are formed on the semiconductor substrate 301, and the transfer electrode 304 is formed through the silicon oxide film 305. .
  • a light shielding film 307 is formed on the transfer electrode 304 via silicon oxide films 305 and 306, and the light shielding film 307 has an opening corresponding to the upper part of the light receiving portion 302.
  • the structure similar to the solid-state imaging device 1 which concerns on the said Embodiment 1 Moreover, there is no place which changes also about structures, such as a vertical CCD part and a horizontal CCD part which are not shown in figure.
  • a hydrogen-containing film 308 is provided on the light-shielding film 307, and an insulating film (hereinafter, “ 309 is provided, and an insulating film (hereinafter, also referred to as “second insulating film” 310) is provided thereon. Yes.
  • the hydrogen-containing film 308 is made of, for example, a plasma silicon nitride film formed using a plasma CVD method.
  • the refractive index of the first insulating film 309 is lower than the refractive index of the second insulating film 310.
  • the light 311 incident on the light shielding film 307 is totally reflected at the interface between the first insulating film 309 and the second insulating film 310. . For this reason, light can be reflected in the direction of the light receiving unit 302, light absorption by the light shielding film 307 can be suppressed, and a decrease in sensitivity of the solid-state imaging device can be suppressed.
  • the film thickness of the first insulating film 309 is a distance at which evanescent light oozes out in the direction of the first insulating film 309 in total reflection at the interface between the first insulating film 309 and the second insulating film 310. It is desirable to make it thicker than, for example, 50 [nm] or more.
  • Electrode light means that when light is incident on a low medium from a medium having a high refractive index, the light is totally reflected when the incident angle is set to a certain critical angle or more. This refers to the phenomenon of light penetrating into the interior.
  • the light shielding film 307 is as much as possible at the opening of the light shielding film 307 (the portion corresponding to the upper part of the light receiving portion 302).
  • the first insulating film 309 made of a material having a refractive index lower than that of the second insulating film 310 exists in the opening of the light shielding film 307. In this region, the first insulating film If the second insulating film 310 is provided by removing 309, the refractive index of the medium in that portion can be increased, and the sensitivity of the solid-state imaging device can be improved.
  • the solid-state imaging device by adopting the above configuration, the light 311 incident on the solid-state imaging device is blocked by the light-shielding film as in the solid-state imaging device 1 according to the first embodiment.
  • the light-shielding film By suppressing absorption by 307 and reflecting more light in the direction of the light receiving unit 302, it is possible to suppress a decrease in sensitivity of the solid-state imaging device.
  • the present invention is useful for realizing a solid-state imaging device having high sensitivity as an imaging device used for a digital camera or the like.
  • Solid-state imaging device 10. Pixel area 21. Vertical CCD unit 22. Horizontal CCD unit 23. Amplifier unit 100. Pixels 101, 301. Semiconductor substrates 102, 302. Light receiving units 103, 303. Charge transfer unit 104, 304. Transfer electrodes 105, 106, 305, 306. Silicon oxide films 107 and 307. Light shielding films 108, 309, 310. Insulating films 109, 308. Hydrogen-containing films 110, 205, 311. Incident rays 201, 202, 203, 204. Flat film

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Abstract

In this solid-state image pickup device, photoelectric conversion regions (102) and transfer regions (103) are formed adjacent to each other in a semiconductor substrate (101). In a region on the semiconductor substrate (101), said region being equivalent to a portion above each of the transfer regions (103), a transfer electrode (104) is provided, and a light blocking film (107) is formed to cover over the transfer electrode (104). The light blocking film (107) has an opening in a portion equivalent to a portion above each of the photoelectric conversion regions (102). On the light blocking film (107), a first insulating film (108) and a second insulating film (109) are sequentially laminated. The second insulating film (109) contains hydrogen, and the refractive index of the first insulating film (108) is lower than that of the second insulating film (109).

Description

固体撮像装置Solid-state imaging device
　本発明は、固体撮像装置に関し、特に、転送電極上の遮光膜の上を覆う絶縁膜の構成に関する。 The present invention relates to a solid-state imaging device, and more particularly to a configuration of an insulating film covering a light shielding film on a transfer electrode.
　固体撮像装置において、ｐ型の半導体基板（シリコン基板）の表層部分に形成されたｎ型半導体領域（光電変換領域）に光が入射すると、そのｎ型半導体領域において、入射した光量に応じて信号電荷が発生する。このようにして個々の画素において発生する該信号電荷より、映像信号を得ることができる。 In a solid-state imaging device, when light is incident on an n-type semiconductor region (photoelectric conversion region) formed on a surface layer portion of a p-type semiconductor substrate (silicon substrate), a signal is generated in the n-type semiconductor region according to the amount of incident light. Charge is generated. Thus, a video signal can be obtained from the signal charges generated in each pixel.
　図９は、特許文献１あるいは特許文献２に代表される従来の固体撮像装置の一例を示す断面図であり、半導体基板９０１上に配列された画素の一つを含む範囲を示している。 FIG. 9 is a cross-sectional view showing an example of a conventional solid-state imaging device represented by Patent Document 1 or Patent Document 2, and shows a range including one of the pixels arranged on the semiconductor substrate 901.
　図９において、半導体基板９０１の表層部分にはフォトダイオードからなる受光部９０２が画素ごとに設けられ、半導体基板９０１の表層部分であって、且つ、受光部９０２の隣接する領域には、受光部９０２で光電変換により生成された電荷を転送するための転送領域９０３が形成されている。さらに、半導体基板９０１上には、シリコン酸化膜９０５が設けられ、当該シリコン酸化膜９０５上であって、転送領域９０３の上部に相当する箇所には、転送電極９０４が設けられている。 In FIG. 9, a light receiving portion 902 made of a photodiode is provided for each pixel on a surface layer portion of a semiconductor substrate 901, and a light receiving portion is formed on the surface layer portion of the semiconductor substrate 901 and adjacent to the light receiving portion 902. A transfer region 903 for transferring charges generated by photoelectric conversion at 902 is formed. Further, a silicon oxide film 905 is provided on the semiconductor substrate 901, and a transfer electrode 904 is provided on the silicon oxide film 905 and at a position corresponding to the upper portion of the transfer region 903.
　図９に示すように、転送電極９０４の上には、受光部９０２の上方で開口を有する遮光膜９０７がＰＳＧ（Phosphorus silicate glass）膜９０６を介して設けられている。この遮光膜９０７は、アルミニウムやタングステン等の金属からなり、受光部９０２に入射しなかった迷光を反射、吸収することによって、迷光が直接、電荷転送領域９０３に入射してスミアと呼ばれる偽信号を発生することを防ぐ。 As shown in FIG. 9, a light shielding film 907 having an opening above the light receiving portion 902 is provided on the transfer electrode 904 via a PSG (Phosphorus silicate glass) film 906. The light shielding film 907 is made of a metal such as aluminum or tungsten, and reflects and absorbs stray light that has not entered the light receiving portion 902, so that the stray light directly enters the charge transfer region 903 and generates a false signal called smear. Prevent it from occurring.
　遮光膜９０７の上には、プラズマシリコン窒化膜９０８が設けられている。このプラズマシリコン窒化膜９０８は、プラズマＣＶＤ法を用いて形成された後にアニールされてなるが、このアニールによってプラズマシリコン窒化膜９０８中に含有されている水素が脱離し、半導体基板９０１表面のダングリングボンドを終端することによって界面準位を低下させ、暗電流を低減することができる。 A plasma silicon nitride film 908 is provided on the light shielding film 907. This plasma silicon nitride film 908 is formed by using the plasma CVD method and then annealed. By this annealing, hydrogen contained in the plasma silicon nitride film 908 is desorbed, and dangling on the surface of the semiconductor substrate 901 is performed. By terminating the bond, the interface state can be lowered and the dark current can be reduced.
　ここで、特許文献１では、プラズマシリコン窒化膜９０８を、化学量論的に安定な組成比Ｓｉ３Ｎ４におけるシリコンの窒素に対する組成比である０．７５よりも小さく、即ち、窒素リッチにすることによって、アニールの際に脱離するＮ－Ｈ結合を増やし、半導体基板９０１表面のダングリングボンドを終端するのに十分な水素を供給することができると示唆されている。 Here, in Patent Document 1, the plasma silicon nitride film 908 is smaller than 0.75 which is the composition ratio of silicon to nitrogen in the stoichiometrically stable composition ratio Si 3 N 4 , that is, nitrogen-rich. Thus, it is suggested that sufficient hydrogen can be supplied to increase the number of NH bonds desorbed during annealing and terminate dangling bonds on the surface of the semiconductor substrate 901.
　さらに、プラズマシリコン窒化膜９０８は、窒素リッチになるほど屈折率が小さくなるため、上方から受光部９０２へ向かって入射した光が遮光膜９０７のエッジの近くで斜めに屈折されることがなく、斜め光が遮光膜９０７と半導体基板９０１との間を多重反射して直接、電荷転送領域９０３に入り込むことによって生じる偽信号、いわゆる、スミアを防ぐことができると示唆されている。 Further, since the refractive index of the plasma silicon nitride film 908 decreases as it becomes richer in nitrogen, light incident on the light receiving portion 902 from above is not refracted obliquely near the edge of the light shielding film 907, and is inclined. It is suggested that a false signal, that is, a so-called smear, which is generated when light enters the charge transfer region 903 directly by multiple reflection between the light shielding film 907 and the semiconductor substrate 901 can be prevented.
　プラズマシリコン窒化膜９０８の上には、層間絶縁膜としてのシリコン酸化膜９０９が堆積されている。 A silicon oxide film 909 as an interlayer insulating film is deposited on the plasma silicon nitride film 908.
特開平６－１１２４５３号公報JP-A-6-112453 特開２００２－３２４８９９号公報JP 2002-324899 A 特開２００３－３０９１１９号公報JP 2003-309119 A
　しかし、上記の従来技術に係る固体撮像装置の構造には、以下の問題がある。 However, the structure of the above-described conventional solid-state imaging device has the following problems.
　図９に示す従来技術に係る固体撮像装置では、遮光膜９０７にタングステンやアルミニウムといった金属膜を使用しても、遮光膜９０７の表面（金属表面）に入射した光は完全に反射されるのではなく、一部が遮光膜９０７に吸収されてしまい固体撮像装置の感度が低下するという問題が生じる。 In the solid-state imaging device according to the prior art shown in FIG. 9, even if a metal film such as tungsten or aluminum is used for the light shielding film 907, the light incident on the surface (metal surface) of the light shielding film 907 is not completely reflected. However, a part of the light is absorbed by the light shielding film 907 and the sensitivity of the solid-state imaging device is lowered.
　特に、図９に示す従来技術に係る固体撮像装置の構成では、遮光膜９０７を覆うプラズマシリコン窒化膜９０８の屈折率が、さらにその上を覆うシリコン酸化膜９０９（層間絶縁膜）の屈折率より大きいため、固体撮像装置に入射した光は、屈折率の高いプラズマシリコン窒化膜９０８に向かって屈折し、プラズマシリコン窒化膜９０８の下に設けられている遮光膜９０７に当たることでこのような問題が発生する。 In particular, in the configuration of the solid-state imaging device according to the prior art shown in FIG. 9, the refractive index of the plasma silicon nitride film 908 covering the light shielding film 907 is more than the refractive index of the silicon oxide film 909 (interlayer insulating film) covering it. Therefore, the light incident on the solid-state imaging device is refracted toward the plasma silicon nitride film 908 having a high refractive index and hits the light shielding film 907 provided under the plasma silicon nitride film 908, thereby causing such a problem. appear.
　なお、特許文献１によれば、プラズマシリコン窒化膜９０８は、窒素リッチになるほど屈折率が小さくなるとされているが、特許文献３によれば、プラズマシリコン窒化膜９０８の組成比を変えて窒素リッチにした場合でも、その屈折率は１．８程度であると記載され、上記問題の解決には至らない。 According to Patent Document 1, the refractive index of the plasma silicon nitride film 908 decreases with increasing nitrogen richness. However, according to Patent Document 3, the composition ratio of the plasma silicon nitride film 908 is changed to increase the nitrogen richness. Even in this case, the refractive index is described to be about 1.8, and the above problem cannot be solved.
　一方、固体撮像装置において、層間絶縁膜として一般的に用いられているシリコン酸化膜９０９の屈折率は、１．４５程度であるため、窒素リッチとしたプラズマシリコン窒化膜９０８の屈折率（１．８程度）であっても、その上を覆うシリコン酸化膜９０８などの膜の屈折率よりはかなり大きいため、上記の問題の解決には至らないと考えられる。 On the other hand, since the refractive index of a silicon oxide film 909 generally used as an interlayer insulating film in a solid-state imaging device is about 1.45, the refractive index (1. However, it is considered that the above problem cannot be solved because the refractive index of the film such as the silicon oxide film 908 covering the silicon oxide film 908 is much higher.
　本発明は、以上の課題に鑑みてなされたものであり、暗電流を低減するためにシリコン酸化膜よりも高い屈折率を有する膜を遮光膜上に形成した構成においても、感度の低下を抑制できる固体撮像装置を提供することを目的とする。 The present invention has been made in view of the above problems, and suppresses a decrease in sensitivity even in a configuration in which a film having a refractive index higher than that of a silicon oxide film is formed on a light shielding film in order to reduce dark current. An object of the present invention is to provide a solid-state imaging device that can be used.
　そこで、本発明では、次の構成を採用することとした。 Therefore, in the present invention, the following configuration is adopted.
　（１）　本発明に係る固体撮像装置では、半導体基板と、転送電極と、遮光膜と、第１の絶縁膜と、第２の絶縁膜と、を備える。 (1) The solid-state imaging device according to the present invention includes a semiconductor substrate, a transfer electrode, a light shielding film, a first insulating film, and a second insulating film.
　・半導体基板には、一方の主面側内部に、入射光を電荷に光電変換する光電変換領域と、生成された電荷を転送する転送領域とが、互いに隣接した状態で設けられている。 In the semiconductor substrate, a photoelectric conversion region for photoelectrically converting incident light into charges and a transfer region for transferring the generated charges are provided adjacent to each other on one main surface side.
　・転送電極は、半導体基板上であって、且つ、転送領域に対応する領域に設けられている。 The transfer electrode is provided on the semiconductor substrate and in a region corresponding to the transfer region.
　・遮光膜は、転送領域の上方を覆い、且つ、光電変換領域の上方に相当する領域が開口されている。 The light shielding film covers the upper area of the transfer area and has an opening corresponding to the upper area of the photoelectric conversion area.
　・第１の絶縁膜は、遮光膜上に形成されている。 The first insulating film is formed on the light shielding film.
　・第２の絶縁膜は、第１の絶縁膜上に形成されている。 The second insulating film is formed on the first insulating film.
　本発明に係る固体撮像装置では、上記構成において、第２の絶縁膜が水素を含有する膜であり、第１の絶縁膜の屈折率が第２の絶縁膜の屈折率よりも低い、ことを特徴とする。 In the solid-state imaging device according to the present invention, in the above configuration, the second insulating film is a film containing hydrogen, and the refractive index of the first insulating film is lower than the refractive index of the second insulating film. Features.
　（２）　本発明に係る固体撮像装置は、半導体基板と、転送電極と、遮光膜と、第１の絶縁膜と、第２の絶縁膜と、第３の絶縁膜と、を備える。 (2) A solid-state imaging device according to the present invention includes a semiconductor substrate, a transfer electrode, a light shielding film, a first insulating film, a second insulating film, and a third insulating film.
　・半導体基板には、一方の主面側内部に、入射光を電荷に光電変換する光電変換領域と、生成された電荷を転送する転送領域とが、互いに隣接した状態で設けられている。 In the semiconductor substrate, a photoelectric conversion region for photoelectrically converting incident light into charges and a transfer region for transferring the generated charges are provided adjacent to each other on one main surface side.
　・転送電極は、半導体基板上であって、且つ、転送領域に対応する領域に設けられている。 The transfer electrode is provided on the semiconductor substrate and in a region corresponding to the transfer region.
　・遮光膜は、転送領域の上方を覆い、且つ、光電変換領域の上方に相当する領域が開口されている。 The light shielding film covers the upper area of the transfer area and has an opening corresponding to the upper area of the photoelectric conversion area.
　・第１の絶縁膜は、遮光膜上に形成されている。 The first insulating film is formed on the light shielding film.
　・第２の絶縁膜は、第１の絶縁膜上に形成されている。 The second insulating film is formed on the first insulating film.
　・第３の絶縁膜は、第２の絶縁膜上に形成されている。 The third insulating film is formed on the second insulating film.
　本発明に係る固体撮像装置では、上記構成において、第１の絶縁膜が水素を含有する膜であり、第２の絶縁膜の屈折率が第３の絶縁膜の屈折率よりも低い、ことを特徴とする。 In the solid-state imaging device according to the present invention, in the above configuration, the first insulating film is a film containing hydrogen, and the refractive index of the second insulating film is lower than the refractive index of the third insulating film. Features.
　上記（１）に係る本発明の固体撮像装置では、水素を含有する第２の絶縁膜中に含有されている水素がアニールによって脱離し、半導体基板表面のダングリングボンドを終端するため、転送領域の界面準位を低下させ、暗電流を低減することができる。 In the solid-state imaging device of the present invention according to (1) above, the hydrogen contained in the second insulating film containing hydrogen is desorbed by annealing and terminates dangling bonds on the surface of the semiconductor substrate. It is possible to reduce the interface state and to reduce the dark current.
　また、遮光膜と第２の絶縁膜との間に、第２の絶縁膜よりも屈折率の低い第１の絶縁膜を挟むことによって、第１の絶縁膜と第２の絶縁膜との界面において遮光膜方向に伝搬する光の反射率を向上させ、固体撮像装置に入射した光が遮光膜まで到達して遮光膜によって一部の光が吸収されることを抑制し、より多くの光を光電変換領域の方向へ反射させることで、固体撮像装置の感度を向上させることができる。 In addition, the first insulating film having a refractive index lower than that of the second insulating film is interposed between the light shielding film and the second insulating film, whereby the interface between the first insulating film and the second insulating film. In this case, the reflectance of the light propagating in the direction of the light shielding film is improved, and the light incident on the solid-state imaging device is prevented from reaching the light shielding film and being partially absorbed by the light shielding film. By reflecting in the direction of the photoelectric conversion region, the sensitivity of the solid-state imaging device can be improved.
　また、上記（２）に係る本発明の固体撮像装置では、水素を含有する第１の絶縁膜中に含有されている水素がアニールによって脱離し、半導体基板表面のダングリングボンドを終端するため、転送領域の界面準位を低下させ、暗電流を低減することができる。また、遮光膜方向に伝搬する光が第２の絶縁膜と第３の絶縁膜との界面で全反射するため、光電変換領域の方向へ光を反射させることができる。これにより、遮光膜による光の吸収を抑制し、固体撮像装置の感度を向上させることができる。 Further, in the solid-state imaging device of the present invention according to (2) above, hydrogen contained in the first insulating film containing hydrogen is desorbed by annealing, and dangling bonds on the surface of the semiconductor substrate are terminated. The interface state of the transfer region can be lowered and the dark current can be reduced. In addition, since light propagating in the direction of the light shielding film is totally reflected at the interface between the second insulating film and the third insulating film, the light can be reflected in the direction of the photoelectric conversion region. Thereby, absorption of the light by a light shielding film can be suppressed and the sensitivity of a solid-state imaging device can be improved.
　以上より、上記（１）および上記（２）に係る本発明の固体撮像装置では、暗電流を低減するためにシリコン酸化膜よりも高い屈折率を有する絶縁膜を遮光膜上に形成した構成においても、遮光膜表面まで到達して吸収される光の量を減らして遮光膜による光吸収を低減し、受光部の方向へ光を反射させることで多くの光を受光部へ導くことができ、感度低下が抑制される。 As described above, in the solid-state imaging device of the present invention according to the above (1) and (2), the insulating film having a higher refractive index than the silicon oxide film is formed on the light shielding film in order to reduce the dark current. However, the amount of light that reaches the light shielding film surface and is absorbed is reduced, light absorption by the light shielding film is reduced, and a lot of light can be guided to the light receiving part by reflecting the light in the direction of the light receiving part, Sensitivity decline is suppressed.
　本発明に係る固体撮像装置では、一例として、次のようなバリエーション構成を採用することができる。 In the solid-state imaging device according to the present invention, the following variation configuration can be adopted as an example.
　上記（１）に係る本発明の固体撮像装置では、第１の絶縁膜が、光電変換領域の上方に相当する部分で開口されている、という構成とすることができる。 In the solid-state imaging device of the present invention according to (1) above, the first insulating film can be opened at a portion corresponding to the upper part of the photoelectric conversion region.
　上記（１）に係る本発明の固体撮像装置では、第２の絶縁膜がプラズマＣＶＤ法を用い形成されたシリコン窒化膜である、という構成とすることができる。 In the solid-state imaging device of the present invention according to (1) above, the second insulating film may be a silicon nitride film formed using a plasma CVD method.
　上記（１）に係る本発明の固体撮像装置では、第１の絶縁膜がシリコン酸化膜である、という構成とすることができる。 The solid-state imaging device of the present invention according to the above (1) can be configured such that the first insulating film is a silicon oxide film.
　上記（１）に係る本発明の固体撮像装置では、第１の絶縁膜の膜厚が１２０［ｎｍ］～２２０［ｎｍ］であり、且つ、第２の絶縁膜の膜厚が８０［ｎｍ］～１３０［ｎｍ］である、という構成とすることができる。 In the solid-state imaging device of the present invention according to (1) above, the thickness of the first insulating film is 120 [nm] to 220 [nm], and the thickness of the second insulating film is 80 [nm]. It can be configured to be 130 nm.
　上記（２）に係る本発明の固体撮像装置では、第２の絶縁膜が、光電変換領域の上方に相当する部分で開口されている、という構成とすることができる。 In the solid-state imaging device of the present invention according to (2) above, the second insulating film can be configured to be opened at a portion corresponding to the upper part of the photoelectric conversion region.
　上記（２）に係る本発明の固体撮像装置では、第１の絶縁膜がプラズマＣＶＤ法を用い形成されたシリコン窒化膜である、という構成とすることができる。 In the solid-state imaging device of the present invention according to (2) above, the first insulating film may be a silicon nitride film formed using a plasma CVD method.
　上記（２）に係る本発明の固体撮像装置では、第２の絶縁膜がシリコン酸化膜であり、且つ、第３の絶縁膜がシリコン窒化膜である、という構成とすることができる。 In the solid-state imaging device of the present invention according to (2) above, the second insulating film can be a silicon oxide film and the third insulating film can be a silicon nitride film.
本発明の実施の形態１に係る固体撮像装置１の全体構成を模式的に示すブロック図である。1 is a block diagram schematically showing an overall configuration of a solid-state imaging device 1 according to Embodiment 1 of the present invention. 固体撮像装置１における画素領域１０の構成を模式的に示す断面図である。2 is a cross-sectional view schematically showing a configuration of a pixel region 10 in the solid-state imaging device 1. FIG. （ａ）は、実施例に係る固体撮像装置での遮光膜とその上部の膜構成における光線の反射を示す概念図であり、（ｂ）は、比較例に係る固体撮像装置での遮光膜とその上部の膜構成における光線の反射を示す概念図である。(A) is a conceptual diagram which shows reflection of the light ray in the light shielding film in the solid-state imaging device which concerns on an Example, and the film structure of the upper part, (b) is the light-shielding film in the solid-state imaging device which concerns on a comparative example, and It is a conceptual diagram which shows reflection of the light ray in the film | membrane structure of the upper part. 反射率のシミュレーション結果を示すグラフである。It is a graph which shows the simulation result of a reflectance. 光の入射角度θ＝６０°の場合における遮光膜付近での各層の膜厚に対する光の反射率シミュレーション結果を示す模式図である。It is a schematic diagram showing a light reflectance simulation result with respect to the film thickness of each layer in the vicinity of the light shielding film when the light incident angle θ is 60 °. 光の入射角度θ＝７０°の場合における遮光膜付近での各層の膜厚に対する光の反射率シミュレーション結果を示す模式図である。It is a schematic diagram showing a light reflectance simulation result with respect to the film thickness of each layer in the vicinity of the light shielding film when the incident angle θ of light is 70 °. 光の入射角度θ＝８０°の場合における遮光膜付近での各層の膜厚に対する光の反射率シミュレーション結果を示す模式図である。It is a schematic diagram showing a light reflectance simulation result with respect to the film thickness of each layer in the vicinity of the light shielding film when the light incident angle θ is 80 °. 本発明の実施の形態２に係る固体撮像装置における画素領域の構成を模式的に示す断面図である。It is sectional drawing which shows typically the structure of the pixel area | region in the solid-state imaging device which concerns on Embodiment 2 of this invention. 従来技術に係る固体撮像装置における画素領域の構成を模式的に示す断面図である。It is sectional drawing which shows typically the structure of the pixel area | region in the solid-state imaging device concerning a prior art.
　以下では、本発明を実施するための形態について、図面を参酌しながら説明する。なお、以下の各実施の形態は、本発明の構成およびそこから奏される作用・効果を分かり易く説明するために用いる例であって、本発明は、本質的な特徴部分以外に何ら以下の形態に限定を受けるものではない。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Each of the following embodiments is an example used for easily explaining the configuration of the present invention and the operations and effects produced therefrom, and the present invention is not limited to the following essential features. The form is not limited.
　［実施の形態１］
　１．固体撮像装置１の全体構成
　本実施の形態に係る固体撮像装置１の全体構成について、図１を用い説明する。なお、本実施の形態では、インタライン転送ＣＣＤ型固体撮像素子を一例としている。 [Embodiment 1]
1. Overall Configuration of Solid-State Imaging Device 1 The overall configuration of the solid-state imaging device 1 according to the present embodiment will be described with reference to FIG. In the present embodiment, an interline transfer CCD type solid-state imaging device is taken as an example.
　図１に示すように、固体撮像装置１では、Ｘ－Ｙ面方向において、複数の画素１００がマトリクス状に配列されている。そして、複数の画素１００に対し、各行間にはＹ軸方向に延伸する垂直ＣＣＤ部２１が設けられ、垂直ＣＣＤ部２１のＹ軸方向下端において、Ｘ軸方向に延伸する水平ＣＣＤ部２２が設けられている。複数の画素１００および垂直ＣＣＤ部２１などを含めた領域が、画素領域１０となる。 As shown in FIG. 1, in the solid-state imaging device 1, a plurality of pixels 100 are arranged in a matrix in the XY plane direction. For each of the plurality of pixels 100, a vertical CCD unit 21 extending in the Y-axis direction is provided between the rows, and a horizontal CCD unit 22 extending in the X-axis direction is provided at the lower end of the vertical CCD unit 21 in the Y-axis direction. It has been. A region including the plurality of pixels 100 and the vertical CCD unit 21 is a pixel region 10.
　水平ＣＣＤ部２２には、出力アンプ部２３が接続されている。 An output amplifier unit 23 is connected to the horizontal CCD unit 22.
　２．画素領域１０の構成
　図２では、固体撮像装置１の１つの画素１００を含む断面図を示しているが、上記のように、固体撮像装置１では、半導体基板１０１内に受光部１０２と電荷転送部１０３が交互に並設されている。また、電荷転送部１０３の上部には、シリコン酸化膜（以下では、区別のため「第１のシリコン酸化膜」と記載する。）１０５を介した状態で、転送電極１０４が設けられている。固体撮像装置１に入射した光１１０は、受光部１０２で光電変換され電荷となるが、その電荷は電荷転送部１０３の領域にて転送される。 2. Configuration of Pixel Region 10 FIG. 2 shows a cross-sectional view including one pixel 100 of the solid-state imaging device 1. As described above, in the solid-state imaging device 1, the light receiving unit 102 and the charge transfer in the semiconductor substrate 101. The parts 103 are arranged alternately. Further, a transfer electrode 104 is provided above the charge transfer unit 103 with a silicon oxide film 105 (hereinafter referred to as “first silicon oxide film” for distinction) 105 interposed therebetween. The light 110 incident on the solid-state imaging device 1 is photoelectrically converted into charges by the light receiving unit 102, and the charges are transferred in the area of the charge transfer unit 103.
　第１のシリコン酸化膜１０５および転送電極１０４の上には、シリコン酸化膜（以下では、区別のため「第２のシリコン酸化膜」と記載する。）１０６が設けられている。第２のシリコン酸化膜１０６の上には、例えば、タングステン（Ｗ）やアルミニウム（Ａｌ）からなる遮光膜１０７が設けられ、電荷転送部１０３に直接光が入り込むことを防ぎ、光の入射により生じる偽信号、所謂、スミアを防ぐことができる。なお、遮光膜１０７は、受光部１０２の上部に相当する部分が開口されている。 On the first silicon oxide film 105 and the transfer electrode 104, a silicon oxide film (hereinafter referred to as a “second silicon oxide film” 106) is provided. A light shielding film 107 made of, for example, tungsten (W) or aluminum (Al) is provided on the second silicon oxide film 106 to prevent direct light from entering the charge transfer unit 103 and to be generated by the incidence of light. False signals, so-called smears, can be prevented. The light shielding film 107 has an opening corresponding to the upper part of the light receiving unit 102.
　遮光膜１０７の上には、絶縁膜１０８が設けられ、絶縁膜１０８の上には、水素含有膜１０９が設けられている。ここで、絶縁膜１０８の屈折率は、水素含有膜１０９の屈折率よりも低い。 An insulating film 108 is provided on the light shielding film 107, and a hydrogen-containing film 109 is provided on the insulating film 108. Here, the refractive index of the insulating film 108 is lower than the refractive index of the hydrogen-containing film 109.
　水素含有膜１０９としてのシリコン窒化膜を、例えば、プラズマＣＶＤ法を用いて形成した後に、アニールすることによって、膜中に含有されている水素が脱離し、半導体基板１０１表面のダングリングボンドを終端する作用を果たす。これによって、半導体基板１０１の界面準位が低下し、暗電流を低減することができる。 A silicon nitride film as the hydrogen-containing film 109 is formed using, for example, a plasma CVD method, and then annealed, whereby hydrogen contained in the film is desorbed, and dangling bonds on the surface of the semiconductor substrate 101 are terminated. Fulfills the function of As a result, the interface state of the semiconductor substrate 101 is lowered, and the dark current can be reduced.
　ここで、プラズマＣＶＤ法で形成されたシリコン窒化膜からなる水素含有膜１０９の屈折率は、シリコンと窒素の組成比に依存するものの約１．９である。 Here, the refractive index of the hydrogen-containing film 109 made of a silicon nitride film formed by the plasma CVD method is about 1.9 although it depends on the composition ratio of silicon and nitrogen.
　一方、このシリコン窒化膜である水素含有膜１０９の上には、一般的にシリコン酸化膜からなる層間絶縁膜が形成されるが（図示を省略）、このシリコン酸化膜の屈折率は約１．４５である。このため、シリコン窒化膜の屈折率は、その上に形成されるシリコン酸化膜の層間絶縁膜の屈折率と比べて高く、固体撮像装置１に入射した光は、屈折率の高いシリコン窒化膜に向かって伝搬し、その下部の遮光膜方向に向かうことになる。 On the other hand, an interlayer insulating film made of a silicon oxide film is generally formed on the hydrogen-containing film 109, which is a silicon nitride film (not shown). The refractive index of this silicon oxide film is about 1. 45. For this reason, the refractive index of the silicon nitride film is higher than the refractive index of the interlayer insulating film of the silicon oxide film formed thereon, and the light incident on the solid-state imaging device 1 enters the silicon nitride film having a high refractive index. Propagated toward the light shielding film in the lower part thereof.
　しかしながら、遮光膜１０７自体に光が当たると一部の光は吸収されてしまうため、受光部１０２に入射する光量が減少し、固体撮像装置１の感度が低下してしまう。 However, when light hits the light shielding film 107 itself, a part of the light is absorbed, so that the amount of light incident on the light receiving unit 102 decreases and the sensitivity of the solid-state imaging device 1 decreases.
　そこで、本実施の形態では、水素含有膜１０９であるシリコン窒化膜と、遮光膜１０７との間に、シリコン窒化膜よりも低い屈折率を有する材料からなる絶縁膜１０８を設けることによって、水素含有膜１０９と絶縁膜１０８との界面において遮光膜１０７方向に伝搬する光の反射率を向上させ、図２中の光線１１０に示すように、固体撮像装置１に入射した光が遮光膜１０７まで到達し難いようにし、これにより遮光膜１０７で一部の光が吸収されることを抑制し、より多くの光を受光部１０２の方向へ反射させることで、固体撮像装置１の感度低下を抑制することができる。 Therefore, in this embodiment, the insulating film 108 made of a material having a lower refractive index than that of the silicon nitride film is provided between the silicon nitride film that is the hydrogen-containing film 109 and the light-shielding film 107, so that the hydrogen-containing film 109 The reflectance of light propagating in the direction of the light shielding film 107 at the interface between the film 109 and the insulating film 108 is improved, and the light incident on the solid-state imaging device 1 reaches the light shielding film 107 as indicated by a light beam 110 in FIG. In this way, it is possible to suppress a part of light from being absorbed by the light shielding film 107 and to reflect more light in the direction of the light receiving unit 102, thereby suppressing a decrease in sensitivity of the solid-state imaging device 1. be able to.
　なお、固体撮像装置１に入射する光は、媒質の屈折率の高いほど絞られて伝搬するため、遮光膜１０７の開口部においては、可能な限り遮光膜１０７に光を当てることなく、光を狭く絞って通すことで受光部１０２への光の到達量が増加し、固体撮像装置１の感度が向上する効果が得られる。そのため、遮光膜１０７が開口された部分（受光部１０２の上部に相当する部分）においては、シリコン窒化膜よりも低い屈折率を有する材料からなる絶縁膜１０８が存在することは好ましくなく、この領域では絶縁膜１０８を除去して水素含有膜１０９を設ければ、この部分における媒質の屈折率を高くでき、固体撮像装置１の感度を向上することができる。 Note that light incident on the solid-state imaging device 1 is narrowed and propagated as the refractive index of the medium is higher. Therefore, in the opening portion of the light shielding film 107, the light is applied to the light shielding film 107 as much as possible. By narrowing down and passing, the amount of light reaching the light receiving unit 102 increases, and the effect of improving the sensitivity of the solid-state imaging device 1 can be obtained. Therefore, it is not preferable that the insulating film 108 made of a material having a refractive index lower than that of the silicon nitride film is present in the portion where the light shielding film 107 is opened (the portion corresponding to the upper portion of the light receiving portion 102). Then, if the insulating film 108 is removed and the hydrogen-containing film 109 is provided, the refractive index of the medium in this portion can be increased, and the sensitivity of the solid-state imaging device 1 can be improved.
　３．光の反射率
　次に、本実施の形態に係る固体撮像装置１での、遮光膜１０７とその上部の膜構成における光の反射率を、シミュレーションを用いて計算した。その結果について、図３から図７を用い説明する。 3. Light Reflectance Next, the light reflectance in the light shielding film 107 and the film structure thereabove in the solid-state imaging device 1 according to the present embodiment was calculated using simulation. The results will be described with reference to FIGS.
　先ず、図３（ａ）に、実施例に係る固体撮像装置のシミュレーション構造を示す。図３（ａ）に示すように、シミュレーション構造は、裏面反射が無いとみなせるほどに十分厚い膜厚のタングステン（Ｗ）からなる平坦膜２０１上に、第１のシリコン酸化膜からなる平坦膜２０２を設け、その上にプラズマシリコン窒化膜からなる平坦膜２０３を設け、更にその上に第２のシリコン酸化膜からなる平坦膜２０４を設けた積層平坦膜である。 First, FIG. 3A shows a simulation structure of the solid-state imaging device according to the embodiment. As shown in FIG. 3A, in the simulation structure, the flat film 202 made of the first silicon oxide film is formed on the flat film 201 made of tungsten (W) having a sufficiently thick film thickness so that it can be considered that there is no back surface reflection. And a flat film 203 made of a plasma silicon nitride film, and a flat film 204 made of a second silicon oxide film is further formed thereon.
　ここで、平坦膜２０１の屈折率ｎおよび消衰係数ｋは、それぞれｎ＝３．５、ｋ＝２．７とし、平坦膜２０２および平坦膜２０４の屈折率ｎおよび消衰係数ｋは、それぞれｎ＝１．４５、ｋ＝０とし、平坦膜２０３の屈折率ｎおよび消衰係数ｋは、それぞれｎ＝１．９、ｋ＝０とした。 Here, the refractive index n and the extinction coefficient k of the flat film 201 are n = 3.5 and k = 2.7, respectively, and the refractive index n and the extinction coefficient k of the flat film 202 and the flat film 204 are respectively n = 1.45 and k = 0, and the refractive index n and extinction coefficient k of the flat film 203 were n = 1.9 and k = 0, respectively.
　次に、図３（ｂ）に、比較例に係る固体撮像装置のシミュレーション構造を示す。図３（ｂ）に示すように、比較例に係るシミュレーション構造は、遮光膜９５１上にプラズマシリコン窒化膜９５２が設けられ、その上にシリコン酸化膜９５３が設けられている。 Next, FIG. 3B shows a simulation structure of the solid-state imaging device according to the comparative example. As shown in FIG. 3B, in the simulation structure according to the comparative example, a plasma silicon nitride film 952 is provided on the light shielding film 951, and a silicon oxide film 953 is provided thereon.
　シミュレーション方法としては、薄膜における光の干渉計算に関して一般的である特性マトリクス法を用いた。ここで、光の入射波長λをλ＝４５０［ｎｍ］、５３０［ｎｍ］、６００［ｎｍ］の３条件とし、入射角度θを変化させて計算を行った。また、反射率の偏光依存性を考慮し、反射率はＰ偏光とＳ偏光の平均値を求めた。図４に、そのシミュレーション結果を示す。 As a simulation method, a characteristic matrix method which is general for light interference calculation in a thin film was used. Here, the calculation was performed with the incident wavelength λ of light being three conditions of λ = 450 [nm], 530 [nm], and 600 [nm], and changing the incident angle θ. In consideration of the polarization dependence of the reflectance, the average value of the P-polarized light and the S-polarized light was obtained as the reflectance. FIG. 4 shows the simulation result.
　なお、実施例においては、平坦膜２０２の膜厚を１００［ｎｍ］とし、平坦膜２０３の厚さは１００［ｎｍ］で統一した。 In the embodiment, the thickness of the flat film 202 is set to 100 [nm], and the thickness of the flat film 203 is set to 100 [nm].
　図４に示すように、これらの構造において光の入射角度θを０～９０°まで変化させた結果、実施例に係る構造の反射率はどの入射角度においても比較例に係る構造よりも高い。この理由について、図３（ａ）と図３（ｂ）とを比較しながら説明する。 As shown in FIG. 4, as a result of changing the incident angle θ of light from 0 to 90 ° in these structures, the reflectance of the structure according to the example is higher than the structure according to the comparative example at any incident angle. The reason for this will be described by comparing FIG. 3 (a) and FIG. 3 (b).
　図３（ｂ）に示すように、比較例に係る構造では、図９に示す従来技術に係る構造と同様に、遮光膜９５１上にプラズマシリコン窒化膜９５２が設けられ、その上にシリコン酸化膜９５３が設けられている。ここで、入射光線９５４は、シリコン酸化膜９５３とプラズマシリコン窒化膜９５２との界面、およびプラズマシリコン窒化膜９５２と遮光膜９５１との界面において反射されるが、一部の光はプラズマシリコン窒化膜９５２と遮光膜９５１との界面において反射されずに、遮光膜９５１で吸収される。 As shown in FIG. 3B, in the structure according to the comparative example, a plasma silicon nitride film 952 is provided on the light shielding film 951 and the silicon oxide film is formed thereon, as in the structure according to the prior art shown in FIG. 953 is provided. Here, incident light 954 is reflected at the interface between the silicon oxide film 953 and the plasma silicon nitride film 952 and at the interface between the plasma silicon nitride film 952 and the light shielding film 951, but some of the light is reflected in the plasma silicon nitride film. The light is not reflected at the interface between 952 and the light shielding film 951 but is absorbed by the light shielding film 951.
　一方、図３（ａ）に示すように、実施例に係る構成では、タングステン（Ｗ）からなる平坦膜（遮光膜）２０１とプラズマシリコン窒化膜からなる平坦膜２０３との間に、第１のシリコン酸化膜である平坦膜２０２を設けることによって、上記比較例に係る構造と比較して、平坦膜２０３と平坦膜２０２との界面において反射が生じる分、平坦膜（遮光膜）２０１まで到達して吸収される光の量を減らすことができ、反射率を増加することができると考えられる。 On the other hand, as shown in FIG. 3A, in the configuration according to the embodiment, the first film is formed between the flat film (light-shielding film) 201 made of tungsten (W) and the flat film 203 made of plasma silicon nitride film. By providing the flat film 202 which is a silicon oxide film, the flat film (light-shielding film) 201 is reached by the amount of reflection at the interface between the flat film 203 and the flat film 202 as compared with the structure according to the comparative example. It is considered that the amount of light absorbed can be reduced and the reflectance can be increased.
　以上の理由から、図４のシミュレーション結果に示す通り、実施例に係る構成のように、遮光膜である平坦膜２０１とプラズマシリコン窒化膜である平坦膜２０３との間に、シリコン酸化膜である平坦膜２０２を設けることによって（図３（ａ）を参照）、当該間にシリコン酸化膜である平坦膜２０２が無い比較例に係る構造（図３（ｂ）を参照）に比べて、平坦膜２０１に向かう光２０５の反射率を高めることができ、平坦膜２０１での光吸収を抑制し、より多くの光を受光部に向かって反射させることができ、固体撮像装置の感度低下を抑制できることを示しているものと考えられる。 For the above reasons, as shown in the simulation results of FIG. 4, a silicon oxide film is provided between the flat film 201 that is a light shielding film and the flat film 203 that is a plasma silicon nitride film as in the configuration according to the embodiment. By providing the flat film 202 (see FIG. 3A), the flat film is compared with the structure according to the comparative example (see FIG. 3B) in which there is no flat film 202 that is a silicon oxide film therebetween. The reflectance of the light 205 toward the 201 can be increased, the light absorption by the flat film 201 can be suppressed, more light can be reflected toward the light receiving unit, and the sensitivity reduction of the solid-state imaging device can be suppressed. It is thought that it shows.
　さらに、図３（ａ）に示す構造の実施例に関し、第１のシリコン酸化膜である平坦膜２０２、およびプラズマシリコン窒化膜である平坦膜２０３の膜厚を、それぞれ変化させたときの反射率の膜厚依存性について、シミュレーションを用いて計算した。そのシミュレーション結果を図５から図７に示す。 Further, in the example of the structure shown in FIG. 3A, the reflectance when the film thicknesses of the flat film 202 as the first silicon oxide film and the flat film 203 as the plasma silicon nitride film are changed. The film thickness dependence was calculated using simulation. The simulation results are shown in FIGS.
　図５から図７において、光の入射波長λはλ＝４５０ｎｍ、５３０ｎｍ、６００ｎｍの３条件とし、図５では、入射角度θ＝６０［°］、図６では、θ＝７０［°］、図７では、θ＝８０［°］とした。そして、各条件の組み合わせに対して、第１のシリコン酸化膜である平坦膜２０２およびプラズマシリコン窒化膜である平坦膜２０３の膜厚を変化させて、反射率を計算した。 5 to 7, the incident wavelength λ of light has three conditions of λ = 450 nm, 530 nm, and 600 nm. In FIG. 5, the incident angle θ = 60 [°], in FIG. 6, θ = 70 [°], 7, θ = 80 [°]. Then, for each combination of conditions, the reflectance was calculated by changing the thickness of the flat film 202 as the first silicon oxide film and the flat film 203 as the plasma silicon nitride film.
　反射率は、入射波長λおよび入射角度θに依存して変わるが、図７に示すように、実施例に係る構造において、最も反射率が高くなる条件は、固体撮像装置に入射した光の遮光膜に向かう入射角度θが略７０［°］程度の時である。このため、図７に示すθ＝７０°での結果から、高い反射率を得るのに適した膜厚の範囲は、第１のシリコン酸化膜である平坦膜２０２の膜厚が１２０［ｎｍ］～２２０［ｎｍ］の範囲であり、且つ、プラズマシリコン窒化膜である平坦膜２０３の膜厚が８０［ｎｍ］～１３０［ｎｍ］の範囲であることがわかる。 Although the reflectivity varies depending on the incident wavelength λ and the incident angle θ, as shown in FIG. 7, in the structure according to the embodiment, the condition for the highest reflectivity is to block the light incident on the solid-state imaging device. This is when the incident angle θ toward the film is about 70 [°]. For this reason, from the result at θ = 70 ° shown in FIG. 7, the film thickness range suitable for obtaining a high reflectance is that the film thickness of the flat film 202 as the first silicon oxide film is 120 [nm]. It can be seen that the thickness of the flat film 203 that is a plasma silicon nitride film is in the range of 80 [nm] to 130 [nm].
　このような膜厚範囲に設定することで、図２に示した本実施の形態に係る固体撮像装置１での、遮光膜１０７に向かって入射した光１１０のうち、５０［％］以上の光を受光部１０２の方向へ反射することができる。 By setting the film thickness in such a range, 50% or more of the light 110 incident on the light shielding film 107 in the solid-state imaging device 1 according to the present embodiment shown in FIG. Can be reflected in the direction of the light receiving unit 102.
　一方で、第１のシリコン酸化膜である平坦膜２０２が形成されていない図９に示す従来技術に係る固体撮像装置の構成では、対応する反射率が、図５から図７に示したシミュレーション結果より、θ＝７０［°］の場合では３０［％］以下である。 On the other hand, in the configuration of the solid-state imaging device according to the related art shown in FIG. 9 in which the flat film 202 which is the first silicon oxide film is not formed, the corresponding reflectance is the simulation result shown in FIGS. Therefore, in the case of θ = 70 [°], it is 30 [%] or less.
　以上の結果より、遮光膜に当たる光の量を入射光の２０［％］と仮定した場合、従来技術に係る固体撮像装置の構成では、遮光膜で反射される光は入射光の６［％］以下であるが、図２に示す本実施の形態に係る固体撮像装置１の構成では、遮光膜１０７で反射される光は入射光の１０［％］以上となることから、本実施の形態に係る固体撮像装置１の構成を採用することによって、従来技術に係る固体撮像装置の構成に比べて、固体撮像装置１の感度を４［％］以上向上することができる。 From the above results, assuming that the amount of light hitting the light shielding film is 20 [%] of the incident light, the light reflected by the light shielding film is 6 [%] of the incident light in the configuration of the solid-state imaging device according to the prior art. In the configuration of the solid-state imaging device 1 according to the present embodiment shown in FIG. 2, the light reflected by the light shielding film 107 is 10% or more of the incident light. By adopting the configuration of the solid-state imaging device 1, the sensitivity of the solid-state imaging device 1 can be improved by 4% or more compared to the configuration of the solid-state imaging device according to the related art.
　以上のように、本実施の形態に係る固体撮像装置１の構成では、入射した光１１０が遮光膜１０７に吸収されることを抑制し、より多くの光１１０を受光部１０２の方向へ反射させることで、感度低下を抑制することができる。 As described above, in the configuration of the solid-state imaging device 1 according to the present embodiment, the incident light 110 is suppressed from being absorbed by the light shielding film 107, and more light 110 is reflected in the direction of the light receiving unit 102. As a result, a decrease in sensitivity can be suppressed.
　［実施の形態２］
　以下、本発明の実施の形態２に係る固体撮像装置について、図８の要部断面図を参照しながら説明する。 [Embodiment 2]
Hereinafter, a solid-state imaging device according to Embodiment 2 of the present invention will be described with reference to a cross-sectional view of the main part of FIG.
　図８に示すように、本実施の形態に係る固体撮像装置においても、半導体基板３０１に受光部３０２および電荷転送部３０３が形成され、シリコン酸化膜３０５を介して転送電極３０４が形成されている。そして、転送電極３０４の上には、シリコン酸化膜３０５，３０６を介して遮光膜３０７が形成され、遮光膜３０７は、受光部３０２の上方に相当する部分が開口されている。これらについては、上記実施の形態１に係る固体撮像装置１と同様の構成であり、また、図示をしない垂直ＣＣＤ部、水平ＣＣＤ部などの構成についても変るところはない。 As shown in FIG. 8, also in the solid-state imaging device according to the present embodiment, the light receiving unit 302 and the charge transfer unit 303 are formed on the semiconductor substrate 301, and the transfer electrode 304 is formed through the silicon oxide film 305. . Then, a light shielding film 307 is formed on the transfer electrode 304 via silicon oxide films 305 and 306, and the light shielding film 307 has an opening corresponding to the upper part of the light receiving portion 302. About these, it is the structure similar to the solid-state imaging device 1 which concerns on the said Embodiment 1, Moreover, there is no place which changes also about structures, such as a vertical CCD part and a horizontal CCD part which are not shown in figure.
　図８に示すように、本実施の形態に係る固体撮像装置では、遮光膜３０７の上に、水素含有膜３０８が設けられ、水素含有膜３０８の上に絶縁膜（以下では、区別のため「第１の絶縁膜」ということがある。）３０９が設けられ、さらに、その上に絶縁膜（以下では、区別のために「第２の絶縁膜」ということがある。）３１０が設けられている。 As shown in FIG. 8, in the solid-state imaging device according to the present embodiment, a hydrogen-containing film 308 is provided on the light-shielding film 307, and an insulating film (hereinafter, “ 309 is provided, and an insulating film (hereinafter, also referred to as “second insulating film” 310) is provided thereon. Yes.
　上記において、水素含有膜３０８は、例えば、プラズマＣＶＤ法を用いて形成されたプラズマシリコン窒化膜からなる。また、第１の絶縁膜３０９の屈折率は、第２の絶縁膜３１０の屈折率よりも低い。 In the above, the hydrogen-containing film 308 is made of, for example, a plasma silicon nitride film formed using a plasma CVD method. In addition, the refractive index of the first insulating film 309 is lower than the refractive index of the second insulating film 310.
　このような構成を有する本実施の形態に係る固体撮像装置においては、遮光膜３０７に向かって入射した光３１１が、第１の絶縁膜３０９と第２の絶縁膜３１０との界面で全反射する。このため、受光部３０２の方向へ光を反射させることができ、遮光膜３０７での光の吸収を抑制することができ、固体撮像装置の感度の低下を抑制することができる。 In the solid-state imaging device according to this embodiment having such a configuration, the light 311 incident on the light shielding film 307 is totally reflected at the interface between the first insulating film 309 and the second insulating film 310. . For this reason, light can be reflected in the direction of the light receiving unit 302, light absorption by the light shielding film 307 can be suppressed, and a decrease in sensitivity of the solid-state imaging device can be suppressed.
　ここで、第１の絶縁膜３０９の膜厚は、第１の絶縁膜３０９と第２の絶縁膜３１０との界面の全反射において、エバネッセント光が第１の絶縁膜３０９の方向へ染み出す距離よりも厚くすることが望ましく、例えば、５０［ｎｍ］以上とすることが望ましい。 Here, the film thickness of the first insulating film 309 is a distance at which evanescent light oozes out in the direction of the first insulating film 309 in total reflection at the interface between the first insulating film 309 and the second insulating film 310. It is desirable to make it thicker than, for example, 50 [nm] or more.
　なお、「エバネッセント光」とは、屈折率の高い媒質から低い媒質に光が入射する場合、入射角をある臨界角以上にすると光は全反射するが、その際に１波長程度まで低媒質側の内部に光が浸透する現象をいう。 “Evanescent light” means that when light is incident on a low medium from a medium having a high refractive index, the light is totally reflected when the incident angle is set to a certain critical angle or more. This refers to the phenomenon of light penetrating into the interior.
　固体撮像装置に入射する光３１１は、媒質の屈折率の高いほど絞られて伝搬するため、遮光膜３０７の開口部（受光部３０２の上方に相当する部分）においては、可能な限り遮光膜３０７に光を当てることなく、光を狭く絞って通すことで受光部３０２への光の到達量が増加し、固体撮像装置の感度が向上する効果が得られる。そのため、遮光膜３０７の開口部においては、第２の絶縁膜３１０よりも低い屈折率を有する材料からなる第１の絶縁膜３０９が存在することは好ましくなく、この領域では、第１の絶縁膜３０９を除去して第２の絶縁膜３１０を設ければ、当該部分における媒質の屈折率を高くでき、固体撮像装置の感度を向上することができる。 Since the light 311 incident on the solid-state imaging device is narrowed and propagates as the refractive index of the medium increases, the light shielding film 307 is as much as possible at the opening of the light shielding film 307 (the portion corresponding to the upper part of the light receiving portion 302). By squeezing light narrowly without passing through the light, the amount of light reaching the light receiving unit 302 increases, and the effect of improving the sensitivity of the solid-state imaging device can be obtained. Therefore, it is not preferable that the first insulating film 309 made of a material having a refractive index lower than that of the second insulating film 310 exists in the opening of the light shielding film 307. In this region, the first insulating film If the second insulating film 310 is provided by removing 309, the refractive index of the medium in that portion can be increased, and the sensitivity of the solid-state imaging device can be improved.
　以上のように、本実施の形態に係る固体撮像装置では、上記構成を採用することで、上記実施の形態１に係る固体撮像装置１と同様に、固体撮像装置に入射した光３１１が遮光膜３０７に吸収されることを抑制し、より多くの光を受光部３０２の方向へ反射させることで、固体撮像装置の感度低下を抑制することができる。 As described above, in the solid-state imaging device according to the present embodiment, by adopting the above configuration, the light 311 incident on the solid-state imaging device is blocked by the light-shielding film as in the solid-state imaging device 1 according to the first embodiment. By suppressing absorption by 307 and reflecting more light in the direction of the light receiving unit 302, it is possible to suppress a decrease in sensitivity of the solid-state imaging device.
　本発明は、ディジタルカメラなどに用いる撮像デバイスとして、高い感度を有する固体撮像装置を実現するのに有用である。 The present invention is useful for realizing a solid-state imaging device having high sensitivity as an imaging device used for a digital camera or the like.
　　１．固体撮像装置
　１０．画素領域
　２１．垂直ＣＣＤ部
　２２．水平ＣＣＤ部
　２３．アンプ部
１００．画素
１０１，３０１．半導体基板
１０２，３０２．受光部
１０３，３０３．電荷転送部
１０４，３０４．転送電極
１０５，１０６，３０５，３０６．シリコン酸化膜
１０７，３０７．遮光膜
１０８，３０９，３１０．絶縁膜
１０９，３０８．水素含有膜
１１０，２０５，３１１．入射光線
２０１，２０２，２０３，２０４．平坦膜 1. Solid-state imaging device 10. Pixel area 21. Vertical CCD unit 22. Horizontal CCD unit 23. Amplifier unit 100. Pixels 101, 301. Semiconductor substrates 102, 302. Light receiving units 103, 303. Charge transfer unit 104, 304. Transfer electrodes 105, 106, 305, 306. Silicon oxide films 107 and 307. Light shielding films 108, 309, 310. Insulating films 109, 308. Hydrogen-containing films 110, 205, 311. Incident rays 201, 202, 203, 204. Flat film

Claims (9)

  1. 　一方の主面側内部に、入射光を電荷に光電変換する光電変換領域と、前記電荷を転送する転送領域とが、互いに隣接した状態で設けられてなる半導体基板と、
    　前記半導体基板上であって、且つ、前記転送領域に対応する領域に設けられた転送電極と、
    　前記転送領域の上方を覆い、且つ、前記光電変換領域の上方に相当する領域が開口された遮光膜と、
    　前記遮光膜上に形成された第１の絶縁膜と、
    　前記第１の絶縁膜上に形成された第２の絶縁膜と、
    を備え、
    　前記第２の絶縁膜は、水素を含有する膜であり、
    　前記第１の絶縁膜の屈折率は、前記第２の絶縁膜の屈折率よりも低い
    　ことを特徴とする固体撮像装置。     A semiconductor substrate in which a photoelectric conversion region for photoelectrically converting incident light into electric charge and a transfer region for transferring the electric charge are provided adjacent to each other inside one main surface side,
    A transfer electrode provided on the semiconductor substrate and in a region corresponding to the transfer region;
    A light-shielding film that covers the upper side of the transfer region and has an opening corresponding to the upper side of the photoelectric conversion region;
    A first insulating film formed on the light shielding film;
    A second insulating film formed on the first insulating film;
    With
    The second insulating film is a film containing hydrogen;
    The solid-state imaging device, wherein the refractive index of the first insulating film is lower than the refractive index of the second insulating film.
  2. 　前記第１の絶縁膜は、前記光電変換領域の上方に相当する領域が開口されている
    　ことを特徴とする請求項１に記載の固体撮像装置。     The solid-state imaging device according to claim 1, wherein the first insulating film has an opening corresponding to an area above the photoelectric conversion region.
  3. 　前記第２の絶縁膜は、プラズマＣＶＤ法を用い形成されたシリコン窒化膜である
    　ことを特徴とする請求項１または請求項２に記載の固体撮像装置。     The solid-state imaging device according to claim 1, wherein the second insulating film is a silicon nitride film formed using a plasma CVD method.
  4. 　前記第１の絶縁膜は、シリコン酸化膜である
    　ことを特徴とする請求項１から請求項３の何れかに記載の固体撮像装置。     The solid-state imaging device according to any one of claims 1 to 3, wherein the first insulating film is a silicon oxide film.
  5. 　前記第１の絶縁膜の膜厚は、１２０ｎｍ～２２０ｎｍであり、
    且つ、
    　前記第２の絶縁膜の膜厚は、８０ｎｍ～１３０ｎｍである
    　ことを特徴とする請求項１から請求項４の何れかに記載の固体撮像装置。     The thickness of the first insulating film is 120 nm to 220 nm,
    and,
    The solid-state imaging device according to any one of claims 1 to 4, wherein the thickness of the second insulating film is 80 nm to 130 nm.
  6. 　一方の主面側内部に、入射光を電荷に光電変換する光電変換領域と、前記電荷を転送する転送領域とが、互いに隣接した状態で設けられてなる半導体基板と、
    　前記半導体基板上であって、且つ、前記転送領域に対応する領域に設けられた転送電極と、
    　前記転送領域の上方を覆い、且つ、前記光電変換領域の上方に相当する領域が開口された遮光膜と、
    　前記遮光膜上に形成された第１の絶縁膜と、
    　前記第１の絶縁膜上に形成された第２の絶縁膜と、
    　前記第２の絶縁膜上に形成された第３の絶縁膜と、
    を備え、
    　前記第１の絶縁膜は、水素を含有する膜であり、
    　前記第２の絶縁膜の屈折率は、前記第３の絶縁膜の屈折率よりも低い
    　ことを特徴とする固体撮像装置。     A semiconductor substrate in which a photoelectric conversion region for photoelectrically converting incident light into electric charge and a transfer region for transferring the electric charge are provided adjacent to each other inside one main surface side,
    A transfer electrode provided on the semiconductor substrate and in a region corresponding to the transfer region;
    A light-shielding film that covers the upper side of the transfer region and has an opening corresponding to the upper side of the photoelectric conversion region;
    A first insulating film formed on the light shielding film;
    A second insulating film formed on the first insulating film;
    A third insulating film formed on the second insulating film;
    With
    The first insulating film is a film containing hydrogen;
    The refractive index of a said 2nd insulating film is lower than the refractive index of a said 3rd insulating film. The solid-state imaging device characterized by the above-mentioned.
  7. 　前記第２の絶縁膜は、前記光電変換領域の上方に相当する領域が開口されている
    　ことを特徴とする請求項６に記載の固体撮像装置。     The solid-state imaging device according to claim 6, wherein an area corresponding to the upper side of the photoelectric conversion area is opened in the second insulating film.
  8. 　前記第１の絶縁膜は、プラズマＣＶＤ法を用い形成されたシリコン窒化膜である
    　ことを特徴とする請求項６または請求項７に記載の固体撮像装置。     The solid-state imaging device according to claim 6, wherein the first insulating film is a silicon nitride film formed using a plasma CVD method.
  9. 　前記第２の絶縁膜は、シリコン酸化膜であり、
    且つ、
    　前記第３の絶縁膜は、シリコン窒化膜である
    　ことを特徴とする請求項６から請求項８の何れかに記載の固体撮像装置。     The second insulating film is a silicon oxide film;
    and,
    The solid-state imaging device according to any one of claims 6 to 8, wherein the third insulating film is a silicon nitride film.
PCT/JP2011/003605 2011-02-14 2011-06-23 Solid-state image pickup device WO2012111047A1 (en)

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Citations (5)

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Publication number Priority date Publication date Assignee Title
JPH06132515A (en) * 1992-10-16 1994-05-13 Sony Corp Solid-state imaging device
JPH10112532A (en) * 1996-10-04 1998-04-28 Sony Corp Image sensing device
JP2000252451A (en) * 1999-03-01 2000-09-14 Matsushita Electronics Industry Corp Solid-state imaging device and manufacture thereof
JP2002319667A (en) * 2001-04-24 2002-10-31 Fuji Film Microdevices Co Ltd Solid-state imaging element and manufacturing method therefor
JP2009295918A (en) * 2008-06-09 2009-12-17 Panasonic Corp Solid-state imaging apparatus, and manufacturing method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06132515A (en) * 1992-10-16 1994-05-13 Sony Corp Solid-state imaging device
JPH10112532A (en) * 1996-10-04 1998-04-28 Sony Corp Image sensing device
JP2000252451A (en) * 1999-03-01 2000-09-14 Matsushita Electronics Industry Corp Solid-state imaging device and manufacture thereof
JP2002319667A (en) * 2001-04-24 2002-10-31 Fuji Film Microdevices Co Ltd Solid-state imaging element and manufacturing method therefor
JP2009295918A (en) * 2008-06-09 2009-12-17 Panasonic Corp Solid-state imaging apparatus, and manufacturing method thereof

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