JP5563179B1 - Solid-state imaging device - Google Patents

Abstract

In the solid-state imaging device, an N region (6a, 6a, 6), which becomes a photoelectric conversion diode at the outer periphery of the upper P region (3a, 3b, 3c) in the island-shaped semiconductor (H1, H2, H3) formed on the substrate (1). 6b, 6c) is formed, and the pixel is formed on the surface layer portion at the upper end of the island-shaped semiconductor (H1, H2, H3) so as to contact the N region (6a, 6b, 6c) and the P region (3a, 3b, 3c). P ⁺ regions (7a, 7b, 7c) connected to the selection line conductor layer (8) are formed. The P ⁺ region (7a) is thinner than the P ⁺ region (7b), and the P ⁺ region (7b) is thinner than the P ⁺ region (7c).

Description

  The present invention relates to a solid-state imaging device, and more particularly to a solid-state imaging device for color imaging in which pixels are formed using island-shaped semiconductors (columnar semiconductors) and high pixel density, high sensitivity, and high dynamic range can be realized.

Solid-state imaging devices for color imaging such as CCD and CMOS type are often used for video cameras, steel cameras and the like. In these applications, there is a demand for improved performance such as higher pixel density, higher sensitivity, and higher dynamic range of a solid-state imaging device for color imaging.

FIG. 6 shows a cross-sectional structure diagram of a conventional CMOS color solid-state imaging device (see, for example, Patent Document 1).
A P region (hereinafter, a P-type semiconductor region containing an acceptor impurity is indicated as “P region”) is separated from a surface of a silicon (hereinafter, “Si”) substrate 100 by, for example, a LOCOS (Local Oxidation of Silicon) method ( Isolation silicon oxide layers (hereinafter referred to as SiO ₂ layers) 101a to 101d are formed. Between these separating SiO ₂ layers 101a to 101d, N regions (hereinafter, N- type semiconductor regions containing donor impurities are indicated as “N regions”) 102a to 102c are formed.

  In FIG. 6, the P region substrate 100 and the N regions 102a to 102c form a photodiode with a PN junction. Incident light (electromagnetic energy wave) incident from the upper surfaces of the N regions 102a to 102c is photoelectrically converted in the N regions 102a to 102c and the P region substrate 100 below the N regions 102a to 102c to generate signal charges (in this case, free electrons). . The generated signal charge is accumulated in the photodiode and is taken out to an output circuit provided outside as a signal output current at a predetermined time.

An interlayer SiO ₂ layer 103 is formed on the separation SiO ₂ layers 101a to 101d and the N regions 102a to 102c. Metal wirings 104 a to 104 d are formed on the interlayer SiO ₂ layer 103. A protective insulating layer 105 made of, for example, SiO ₂ or an organic material layer is formed on the interlayer SiO ₂ layer 103 and the metal wirings 104a to 104d.

  In FIG. 6, the upper surface of the protective insulating layer 105 is flattened. A red (R) color filter 106R, a green (G) color filter 106G, and a green (G) color filter 106G are formed on the protective insulating layer 105 so as to surround the N regions 102a to 102c where the photodiodes are formed when viewed from the direction perpendicular to the upper surface. A blue (B) color filter 106B is disposed. Separation insulating layers 107a to 107c are formed between the red (R) color filter 106R, the green (G) color filter 106G, and the blue (B) color filter 106B.

  Among the incident light incident from the upper surfaces of the N regions 102a to 102c, the red (R) color filter 106R is a layer that mainly transmits red wavelength light. The green (G) color filter 106G is a layer that mainly transmits green wavelength light. The blue (B) color filter 106B is a layer that mainly transmits blue wavelength light.

Red (R) color filter 106R (hereinafter abbreviated as “color filter 106R”), green (G) color filter 106G (hereinafter abbreviated as “color filter 106G”), blue (B) color The filter 106B (hereinafter abbreviated as “color filter 106B”) is formed of a photoresist containing a pigment or a dye. Green (G) color filter 106G is formed by photolithography (Photolithography) technique, it is covered with a protective insulating layer 105 and the separating insulating layer 107a from the color filter 106G. A color filter 106R and a color filter 106B are formed over the isolation insulating layer 107a by photolithography. The isolation insulating layer 107c also functions as a protective layer for the color filters 106R, 106G, and 106B.

The separation SiO ₂ layers 101a to 101d, the N regions 102a to 102c, and the metal wirings 104a to 104d formed on the P region substrate 100 shown in FIG. 6 are microfabrication techniques used in microprocessors, memories, and the like. It is formed by advanced CMOS microfabrication technology. Although not shown in FIG. 6, a driver circuit, a signal processing circuit, and the like are formed on the P region substrate 100 in the same manner as the separation SiO ₂ layers 101a to 101d, the N regions 102a to 102c, and the metal wirings 104a to 104d. Therefore, a CMOS transistor is formed by this advanced CMOS microfabrication technology.

  On the other hand, the color CMOS 106R, the color filter 106G, and the color filter 106B cannot be used with this advanced CMOS fine processing technique, but are formed by a photolithography technique using a different photoresist material.

  The size (minimum processing size) of the color filter 106R, the color filter 106G, and the color filter 106B by this photolithography technology is coarser (larger) than the size that can be miniaturized by the above-described advanced CMOS micro processing technology. . As described above, the fact that the fine processing technology cannot be applied to the color filters 106R, 106G, and 106B prevents further increase in the pixel density of the CMOS solid-state imaging device.

Furthermore, the process and apparatus for forming the color filters 106R, 106G, and 106B are different from the process and apparatus used in the above-described advanced CMOS microfabrication technology, and cause an increase in cost. This is a problem for reducing the cost of the solid-state imaging device.
In addition, since light absorption occurs in the color filters 106R, 106G, and 106B itself, the color filter 106R cannot realize a light transmittance of 100% in the red (R) wavelength region. Similarly, in the color filter 106G and the color filter 106B, it is impossible to realize 100% light transmittance in the green (G) wavelength region and the blue (B) wavelength region, respectively. Thus, the light absorption that hinders the improvement of the light transmittance of the color filters 106R, 106G, and 106B hinders the high sensitivity of the CMOS color solid-state imaging device.

Hereinafter, another conventional solid-state imaging device for color imaging will be described with reference to FIGS. 7A to 7C.
FIG. 7A shows a cross-sectional structure diagram of a solid-state imaging device in which one pixel is formed in one island-shaped semiconductor (see, for example, Patent Document 2).
Referring to FIG. 7A, a signal line N ⁺ region 112 (hereinafter, a semiconductor region containing a large amount of donor impurities is referred to as an “N ⁺ region”) is formed on a substrate 111. An island-shaped semiconductor 110 is formed on the signal line N ⁺ region 112. An insulating layer 114 is formed in the island-shaped semiconductor 110 and on the outer periphery of the P region 113 connected to the signal line N ⁺ region 112, and a conductor layer 115 is formed with the insulating layer 114 interposed therebetween. An N region 116 is formed on the outer periphery of the P region 113 above the conductor layer 115. On the N region 116 and the P region 113, a P ⁺ region (hereinafter, a semiconductor region containing a lot of acceptor impurities is referred to as a “P ⁺ region”) 117 is formed. The P ⁺ region 117 is connected to the pixel selection line conductor layer 118. The insulating layers 114 described above are connected to each other so as to surround the outer periphery of the island-shaped semiconductor 110. Similar to the insulating layer 114, the conductor layers 115 are connected to each other so as to surround the outer periphery of the island-shaped semiconductor 110.

In this solid-state imaging device, a photodiode region 119 is formed from a P region 113 and an N region 116 in the island-shaped semiconductor 110. Here, when light enters from the P ⁺ region 117 side of the upper surface layer of the island-shaped semiconductor 110, signal charges (here, free electrons) are generated in the photoelectric conversion region in the photodiode region 119. The generated signal charge is accumulated mainly in the N region 116 of the photodiode region 119.

In the island-shaped semiconductor 110, a junction field effect transistor is configured with the N region 116 as a gate, the P ⁺ region 117 as a source, and the P region 113 in the vicinity of the signal line N ⁺ region 112 as a drain.
In this solid-state imaging device, the drain-source current (output signal) of the junction field effect transistor changes according to the signal charge amount accumulated in the N region 116 and is taken out from the signal line N ⁺ region 112 as a signal output. .

Further, in the island-shaped semiconductor 110, the N region 116 of the photodiode region 119 is the source, the conductor layer 115 is the gate, the signal line N ⁺ region 112 is the drain, and the P region between the N region 116 and the signal line N ⁺ region 112. A MOS transistor having the channel 113 as a channel is formed.
In this solid-state imaging device, the signal charge accumulated in the N region 116 is removed to the signal line N ⁺ region 112 by applying an ON voltage (high level voltage) to the conductor layer 115 that is the gate of the MOS transistor. The

  In this specification, “high level voltage” indicates a higher level positive voltage when the signal charge is a free electron, and “low level voltage” is compared with this “high level voltage”. The voltage with a low absolute value shall be said. Therefore, when the signal charge is a hole, “high level voltage” means a lower level negative voltage, and “low level voltage” means a voltage closer to 0V than “high level voltage”. And

The imaging operation of the solid-state imaging device is based on the following operations (1) to (3) in a state where the ground voltage (= 0 V) is applied to the signal line N ⁺ region 112, the conductor layer 115, and the P ⁺ region 117. Become.
(1) Island-like semiconductor 110 signal charge storage operation of storing signal charges generated in the photoelectric conversion region (photodiode region 119) to the N region 116 by the incident light from the upper end table layer,
(2) In the state where the ground voltage is applied to the signal line N ⁺ region 112 and the conductor layer 115 and the positive voltage is applied to the P ⁺ region 117, the N region 116 changed according to the amount of accumulated signal charge Signal charge read operation for reading the source / drain current of the junction field effect transistor modulated by the potential as the signal current,
(3) After this signal charge reading operation, a ground voltage is applied to the P ⁺ region 117 and a positive voltage is applied to the conductor layer 115 and the signal line N ⁺ region 112 and stored in the N region 116. Reset operation for removing the signal charge that has been applied to the signal line N ⁺ region 112.

FIG. 7B is a plan view of a conventional solid-state imaging device in which island-shaped semiconductors P11 to P33 (corresponding to the island-shaped semiconductor 110 in FIG. 7A) constituting pixels are arranged in a two-dimensional matrix. On the signal line N ⁺ regions 112a, 112b, and 112c (corresponding to the signal line N ⁺ region 112 in FIG. 7A), island-shaped semiconductors P11 to P33 that form pixels are formed.

  In these island-shaped semiconductors P11 to P33, the pixel selection line conductor layers 118a, 118b, and 118c (corresponding to the pixel selection line conductor layer 118 shown in FIG. 7A) are formed so as to be connected to each other in the rows extending in the horizontal direction. Yes. Similarly, in the island-shaped semiconductors P11 to P33 constituting the pixel, the conductor layers 115a, 115b, and 115c (corresponding to the conductor layer 115 in FIG. 7A) are formed so as to be connected to each other in the rows extending in the horizontal direction. ing.

  On the island-shaped semiconductors P11 to P33, blue (B) color filters B1, B2, and B3, red (R) color filters R1, R2, and R3, and green (G) color filters G1, G2, and G3 are provided. Is formed.

  With the above configuration, the blue (B) signal current is obtained from the pixels of the island-shaped semiconductors P11, P21, and P31, and the green (G) signal current is obtained from the pixels of the island-shaped semiconductors P12, P22, and P32. A red (R) signal current is obtained from the pixels of the semiconductors P13, P23, and P33.

In the configuration shown in FIG. 7B, the mask color filter B1, B2, B3, R1, R2, R3, G1, G2, G3, mask alignment margin in manufacture required to form surrounding the island-shaped semiconductor P11~P33 In order to ensure the above, a space is required between the island-shaped semiconductors P11 to P33. This limits the density of pixels. Furthermore, in the solid-state imaging device of this conventional example, as in the solid-state imaging device shown in FIG. 6, light absorption at the color filters B1, B2, B3, R1, R2, R3, G1, G2, and G3 increases sensitivity. It has become an impediment to the realization.

FIG. 7C shows a cross-sectional structure diagram along the line CC ′ in FIG. 7B.
Referring to FIG. 7C, signal line N ⁺ regions 112a, 112b, 112c are formed on substrate 111a, and island-shaped semiconductors P11, P12, P13 are formed on signal line N ⁺ regions 112a, 112b, 112c. . An insulating layer 120a is formed between the island-shaped semiconductors P11, P12, P13 and on the substrate 111a, and P regions 113a, 113b connected to the signal line N ⁺ regions 112a, 112b, 112c of the island-shaped semiconductors P11, P12, P13, A conductor layer 115a is formed on the outer periphery of 113c via insulating layers 114a, 114b, and 114c. The conductor layer 115a is formed so that the island-shaped semiconductors P11, P12, and P13 are connected to each other, and is formed on the outer periphery of the island-shaped semiconductors P11, P12, and P13 located above the upper end of the conductor layer 115a. Regions 116a, 116b, and 116c are formed. An insulating layer 120b is formed between the island-shaped semiconductors P11, P12, and P13 and on the conductor layer 115a and the insulating layer 120a, and P ⁺ regions 117a, 117b, and 117c are formed on the top surface layer of the island-shaped semiconductors P11, P12, and P13. Is formed. A pixel selection line conductor layer 118a is formed on the insulating layer 120b so as to be connected to the P ⁺ regions 117a, 117b, and 117c. An insulating layer 120c is formed on the insulating layer 120b, the pixel selection line conductor layer 118a, and the P ⁺ regions 117a, 117b, and 117c. The surface of the insulating layer 120c is flattened, and a blue (B) color filter B1, a green (G) color filter G1, and a red (R) color filter R1 are formed on the insulating layer 120c. An overcoat insulating layer 120d is formed on the color filters B1, G1, R1 and the insulating layer 120c. These color filters B1, G1, and R1 are formed using a manufacturing method similar to that of the solid-state imaging device shown in FIG. 6, unlike the microfabrication technique used in the pixel structure of the island-shaped semiconductors P11, P12, and P13. Therefore, there is a problem of cost reduction along with high integration of pixels.

  Hereinafter, another conventional solid-state imaging device capable of performing color imaging without using a color filter will be described with reference to FIGS. 8A to 8D.

FIG. 8A shows a cross-sectional structure diagram of this solid-state imaging device (see, for example, Patent Document 3).
Referring to FIG. 8A, an N region (N well) 122 is formed in a P region substrate 121, and a P region (P well) 123 is formed in the N region 122. Here, an N region 124 is formed in the P region 123. The diode composed of the P region substrate 121 and the N region 122, the diode composed of the N region 122 and the P region 123, and the diode composed of the P region 123 and the N region 124 are respectively reverse-biased.
Here, the depth of the N region 124 is preferably about 0.2 μm from the surface of the P region substrate 121, and the depth of the P region 123 is about 0.6 μm from the surface of the P region substrate 121. The depth of the N region 122 is preferably about 2 μm from the surface of the P region substrate 121.

Of the light incident from the front surface of the P region substrate 121, mainly blue (B) wavelength light, photoelectrically constituted diode region 126a from the P region 123 and N region 124 (in FIG. 8A, a region surrounded by a dotted line) The converted signal charges generated are accumulated in the diode region 126a. Mainly green (G) wavelength light is photoelectrically converted in a diode region 126b (region surrounded by a dotted line in FIG. 8A) composed of a P region 123 and an N region 122, and the generated signal charge is accumulated in the diode region 126b. The Then, mainly the red (R) wavelength light is photoelectrically converted in the diode region 126c (region surrounded by a dotted line in FIG. 8A) composed of the P region substrate 121 and the N region 122, and the generated signal charge is transferred to the diode region 126b. Accumulated.

  Then, the signal charge accumulated in the diode region 126a is read from the ammeter 125a as a blue (B) signal, and the signal charge accumulated in the diode region 126a is read from the ammeter 125b as a green (G) signal. The signal charge accumulated in the diode region 126c is read out from the ammeter 125c as a red (R) signal.

The reason why the solid-state imaging device shown in FIG. 8A can perform color imaging without using a color filter is to use the light absorption characteristics of the semiconductor shown in FIG. 8B (in this case, made of silicon (Si)).
As shown in FIG. 8B, most of blue (B) wavelength light (λ = 400 nm) is absorbed near the Si (silicon) surface, and green (G) wavelength light (λ = 550 nm), red (R) wavelength light. As the wavelength (λ) increases (λ = 700 nm), light reaches the inside of Si (silicon) and is absorbed. Thereby, mainly the blue (B) signal is obtained from the diode region 126a, the mainly green (G) signal is obtained from the diode region 126b, and the mainly red (R) signal is obtained from the diode region 126c.

FIG. 8C shows the optical wavelength (λ) dependence of the output obtained from the ammeters 125a, 125b, and 125c.
As shown in FIG. 8C, the blue (B) signal output VB from the ammeter 125a is mainly blue (B) wavelength light output component, and the green (G) signal output VG from the ammeter 125b is mainly green (G). The wavelength light output component and the red (R) signal output VR from the ammeter 125c mainly have a red (R) wavelength light output component, respectively. These signal outputs VB, VG, VR are subjected to signal arithmetic processing such as white balance, for example, thereby obtaining a predetermined RGB signal.

In FIG. 8D, a cross-sectional structure shown in FIG. 8A, a plan view and an output circuit as viewed from the front surface of the P region substrate 121.
As shown in FIG. 8D, an N region (N well) 122 is formed in the P region substrate 121, and a P region (P well) 123 is formed in the N region 122. An N region 124 is formed in the P region 123. A contact hole 127 a is formed in the N region 124 on the same surface as the surface of the P region substrate 121, a contact hole 127 b is formed in the P region 123, and a contact hole 127 c is formed in the N region 122.

  The N region 124 and the output circuit 129a (region surrounded by a dotted line in FIG. 8D) are connected to each other through the contact hole 127a and a lead line 128a connected to the contact hole 127a. The P region 123 and the output circuit 129b (region surrounded by a dotted line in FIG. 8D) are connected to each other through the contact hole 127b and a lead line 128b connected to the contact hole 127b. The N region 122 and the output circuit 129c (region surrounded by a dotted line in FIG. 8D) are connected to each other through the contact hole 127c and a lead line 128c connected to the contact hole 127c.

Output circuit 129a, 129b, 129c, respectively, an amplifier MOS transistor Am for detecting the voltage of the N-region 124, P region 123, N regions 122, row select (row selection) MOS transistor RS, diode region 126a, 126b , 126c, and reset MOS transistors Re for removing signal charges accumulated in 126c. Here, the blue (B) signal is a blue (B) signal line 130a, the green (G) signal is a green (G) signal line 130b, and the red (R) signal is a red (R) signal line 130c. Respectively. These output circuits 129 a, 129 b, and 129 c are formed on the surface of the P region substrate 121 outside the N region 122.

  The solid-state imaging device shown in FIGS. 8A and 8D can perform color imaging without using a color filter, and the diode regions 126a, 126b, and 126c for photoelectric conversion of RGB wavelength light are deeper than the solid-state imaging device shown in FIG. It is characterized by being formed in the direction.

  However, in this solid-state imaging device, the N region 124 that receives blue (B) wavelength light that requires the largest light receiving area is formed inside the P region 123 and the N region 122, and therefore, a predetermined blue (B ) When obtaining the wavelength photosensitivity, the pixel size becomes large. There is also a problem that a signal of white (W) wavelength light including all of blue (B) wavelength light, green (G) wavelength light, and red (R) wavelength light cannot be obtained.

In the solid-state imaging device shown in FIG. 6, in addition to the pixels provided with the color filters 106B, 106G, and 106R, new pixels not provided with the color filters 106B, 106G, and 106R are formed, and white (W) wavelengths are formed from the pixels. By obtaining an optical signal, high sensitivity or high dynamic range can be achieved (for example, see Non-Patent Documents 1 and 2).
According to this technique, since the white (W) pixel can read a larger signal current than other RGB pixels, it utilizes the fact that a high SN ratio (signal / noise ratio) can be obtained. In contrast, the solid-state imaging device shown in FIG. 8A cannot directly read the signal current of white (W) wavelength light.

US Patent Application Publication No. 2005/0082627 US Patent Application Publication No. 2010/0200731 US Patent Application Publication No. 2012/104478 US Patent Application Publication No. 2012/0025281 US Patent Application Publication No. 2011/0215381 US Patent Application Publication No. 2011/0220969

H.Honda, Y.Iida, Y.Egawa, H.Seki; “A Color CMOS Imager with 4 × 4 White-RGB Color Filter Array for Increased Low-Illumination Signal-to-Noise Ratio”, III Transaction on Electron Devices, Vol.56, No.11, pp.2398-2402 (2009) Y.Egawa, N.Tanaka, N.Kawai, H.Seki, A.Nakano, H.Honda, Y.Iida, M.Monoi: “A White-RGB CFA-Patterned CMOS Image Sensor with Wide Dynamic Range”, ISSCC 2008, Digest of Technical Papers, pp.52-53 (2008)

  In the conventional solid-state imaging device shown in FIGS. 6 and 7C, the pixel structure formed below the color filters 106B, 106G, 106R, B1, G1, and R1 is formed by using advanced CMOS microfabrication technology.

  On the other hand, the color filters 106B, 106G, 106R, B1, G1, and R1 cannot be used with this CMOS microfabrication technique, and are formed by a photolithography technique using a photoresist material different from this.

  Therefore, the microfabrication dimensions of the color filters 106B, 106G, 106R, B1, G1, and R1 are coarser (larger) than the microfabrication dimensions of the advanced CMOS microfabrication technology. For this reason, the fine processing technology of the color filters 106B, 106G, 106R, B1, G1, and R1 limits the further increase in pixel density of the CMOS solid-state imaging device.

  Further, the processes and apparatuses for forming the color filters 106B, 106G, 106R, B1, G1, and R1 are different from the processes and apparatuses used in the advanced CMOS microfabrication technology, which causes an increase in cost. This is a problem for reducing the cost of the solid-state imaging device.

  Further, the R, G, and B color filters 106R, 106G, 106B, B1, G1, and R1 in the conventional solid-state imaging device shown in FIGS. 6 and 7C absorb light by the material itself, and therefore the color filters 106R and R1. Thus, 100% light transmittance cannot be realized in the red (R) wavelength region. Similarly, the color filters 106G and G1 and the blue (B) color filters 106B and B1 cannot realize a light transmittance of 100% in the green (G) wavelength region and the blue (B) wavelength region. Thus, the light absorption that hinders the improvement of the light transmittance of the color filters 106R, 106G, 106B, B1, G1, and R1 hinders the high sensitivity of the CMOS color solid-state imaging device.

  In the conventional solid-state imaging device shown in FIG. 8A, diode regions 126a, 126b, and 126c that photoelectrically convert RGB wavelength light are formed so as to overlap each other in the depth direction, and blue (the largest light-receiving area is required). B) An N region 124 that receives wavelength light is formed inside the P region 123 and the N region 122. For this reason, when it is going to obtain predetermined blue (B) wavelength photosensitivity, a pixel size will become large. Further, since it is not possible to directly obtain a signal of white (W) wavelength light including all of blue (B) wavelength light, green (G) wavelength light, and red (R) wavelength light, white (W) wavelength light There is a situation where high sensitivity and high dynamic range using signals cannot be realized.

The solid-state imaging device for color imaging of the present invention is
In a solid-state imaging device in which a plurality of pixels are formed of island-shaped semiconductors and are two-dimensionally arranged in a pixel region,
A first semiconductor region is formed on the substrate,
A base semiconductor region constituting the island-shaped semiconductor is formed on the first semiconductor region,
A second semiconductor region that forms a diode with the mother semiconductor region is formed on an outer periphery of the mother semiconductor region spaced from the first semiconductor region;
A third semiconductor region having a conductivity type opposite to the second semiconductor region is formed on the second semiconductor region so as to be in contact with the base semiconductor region,
In the third semiconductor region, incident light incident from the top surface of the island-shaped semiconductor is absorbed by the third semiconductor region, and signal charges generated thereby are recombined in the third semiconductor region to disappear. Contains a sufficient amount of acceptor or donor impurities to
The island-shaped semiconductor is formed including the third semiconductor region having at least two different thicknesses,
Imaging operation by the solid-state imaging device,
A photoelectric conversion operation that absorbs light incident from an upper surface of the island-shaped semiconductor and generates a signal charge in a diode region including the second semiconductor region and the base semiconductor region;
A signal charge accumulation operation for accumulating the generated signal charge in the diode region;
Junction field effect using either the first semiconductor region or the third semiconductor region as a source or drain, the second semiconductor region as a gate, and the base semiconductor region surrounded by the second semiconductor region as a channel A stored signal charge amount reading operation for detecting a signal charge amount stored in the diode region by detecting a source / drain current flowing in the transistor;
A signal charge removal operation for removing signal charges accumulated in the diode region in the first semiconductor region,
It is characterized by that.

The plurality of island- shaped semiconductors are
A first island-shaped semiconductor having the third semiconductor layer that transmits blue wavelength light, green wavelength light, and red wavelength light, which is incident from the top surface of the island-shaped semiconductor;
A second island-shaped semiconductor having the third semiconductor layer that absorbs blue wavelength light incident from an upper surface of the island-shaped semiconductor;
A third island-shaped semiconductor having at least the third semiconductor layer that absorbs blue wavelength light and green wavelength light incident from the surface of the upper end portion of the island-shaped semiconductor;
The diode region of the first island-shaped semiconductor is photoelectrically converted from blue wavelength light, green wavelength light, and red wavelength light that is incident from the upper end surface of the first island-shaped semiconductor, and the photoelectrically converted signal charges. Accumulation and
The diode region of the second island-shaped semiconductor performs photoelectric conversion of green wavelength light and red wavelength light incident from the upper end surface of the second island-shaped semiconductor, and accumulation of the photoelectrically converted signal charge. ,
The diode region of the third island-shaped semiconductor is configured to perform photoelectric conversion of red wavelength light incident from the upper end surface of the third island-shaped semiconductor and accumulation of signal charges that have been photoelectrically converted.
The thickness of the third semiconductor region of the first island-shaped semiconductor is smaller than the thickness of the third semiconductor region of the second island-shaped semiconductor, and the thickness of the third semiconductor region of the second island-shaped semiconductor is the thickness of the third semiconductor region. Less than the thickness of the third semiconductor region of the third island-shaped semiconductor, and
The first island-shaped semiconductor, the second island-shaped semiconductor, and the third island-shaped semiconductor are formed adjacent to each other.
It is preferable.

Wherein the first island-shaped semiconductor, or the one of the second island-shaped semiconductor primary color type or a complementary color type color filter being provided on at, the light transmitted through the color filter is the color filter It is preferable that a light wavelength component for performing light absorption and signal charge accumulation in the diode region in the first island-shaped semiconductor or the second island-shaped semiconductor located below is included.

In the pixel region, color filter and the first island-shaped semiconductor formed on the upper part data, the first island-shaped semiconductor that does not form a color filter on top that transmits the blue wavelength light passing through the blue wavelength light When, white signal current containing a is formed, the color filter is a blue wavelength light component from the first island-shaped semiconductor is not formed on the top which transmits the blue wavelength light, green wavelength light component and red wavelength light component It is preferable to be obtained.

The third semiconductor region transmits blue wavelength light, green wavelength light, and red wavelength light incident from an upper end surface of the island-shaped semiconductor,
The third semiconductor region absorbs blue wavelength light incident from the top surface of the island-shaped semiconductor,
The plurality of island-shaped semiconductors are
A fourth island-shaped semiconductor having a diode region that performs photoelectric conversion of blue wavelength light, green wavelength light, and red wavelength light that has been transmitted through the third semiconductor region, and accumulation of the photoelectrically converted signal charge;
A fifth island-shaped semiconductor having a diode region that performs photoelectric conversion of one or both of green wavelength light and red wavelength light that has passed through the third semiconductor region, and accumulation of the photoelectrically converted signal charge; And
A thickness of the third semiconductor region of the fifth island-shaped semiconductor is equal to or greater than a thickness of the third semiconductor region of the fourth island-shaped semiconductor;
A sixth island-shaped semiconductor having a structure similar to that of the second semiconductor region and the third semiconductor region in the fourth island-shaped semiconductor and the fifth island-shaped semiconductor is formed in the pixel region,
A primary color type or a complementary color type color filter is formed on the sixth island-shaped semiconductor,
The fourth island-shaped semiconductor, the fifth island-shaped semiconductor, and the sixth island-shaped semiconductor are formed adjacent to each other.
It is preferable.

The third semiconductor region transmits blue wavelength light, green wavelength light, and red wavelength light incident from an upper end surface of the island-shaped semiconductor,
The third semiconductor region absorbs blue wavelength light incident from the top surface of the island-shaped semiconductor,
The plurality of island-shaped semiconductors are
A seventh island-shaped semiconductor having a diode region that performs photoelectric conversion of blue wavelength light, green wavelength light, and red wavelength light transmitted through the third semiconductor region, and accumulation of signal charges obtained by the photoelectric conversion;
An eighth island-shaped semiconductor having a diode region that performs photoelectric conversion of green wavelength light and red wavelength light transmitted through the third semiconductor region and accumulation of the photoelectrically converted signal charge;
A thickness of the third semiconductor region of the eighth island-shaped semiconductor is formed to be greater than a thickness of the third semiconductor region of the seventh island-shaped semiconductor;
A ninth island-shaped semiconductor having the same structure as the second semiconductor region and the third semiconductor region in the seventh island-shaped semiconductor and the eighth island-shaped semiconductor is formed in the pixel region,
A primary color type or complementary color type color filter is formed on the ninth island-shaped semiconductor,
The seventh island-shaped semiconductor, the eighth island-shaped semiconductor, and the ninth island-shaped semiconductor are formed adjacent to each other.
It is preferable.

An insulating layer that transmits light is formed between the substrate and the first semiconductor region, and the insulating layer has a thickness from the insulating layer out of the rays incident from the top surface of the island-shaped semiconductor. island-like semiconductor said diode red wave Adjust amount of light returning to the region of the are set to be larger than the green wavelength components, it is preferable.

  In the pixel region, it is preferable that in the third semiconductor region, the island-shaped semiconductors having at least two different thicknesses are arranged in a zigzag shape or a checkered shape.

  According to the present invention, it is possible to provide a solid-state imaging device in which high pixel density, high sensitivity, and high dynamic range are realized.

1 is a cross-sectional structure diagram of a solid-state imaging device according to a first embodiment of the present invention. It is a top view of the solid-state imaging device concerning a 1st embodiment. It is a cross-section figure explaining the manufacturing method of the solid-state imaging device concerning a 1st embodiment. It is a cross-section figure explaining the manufacturing method of the solid-state imaging device concerning a 1st embodiment. It is a cross-section figure explaining the manufacturing method of the solid-state imaging device concerning a 1st embodiment. It is a cross-section figure explaining the manufacturing method of the solid-state imaging device concerning a 1st embodiment. It is a cross-section figure of the solid-state imaging device provided with the color filter for green (G) concerning a 2nd embodiment of the present invention. It is a top view of the solid-state imaging device provided with the color filter for green (G) concerning a 2nd embodiment. It is a cross-section figure of the solid-state imaging device provided with the color filter for blue (B) concerning a 2nd embodiment. It is a cross-section figure of the solid-state imaging device provided with the color filter for green (G) concerning a 3rd embodiment of the present invention. It is a cross-section figure of the solid-state imaging device provided with the color filter for red (R) concerning a 3rd embodiment. It is a cross-section figure of the solid-state imaging device concerning a 4th embodiment of the present invention. It is sectional drawing of the solid-state imaging device of the prior art example which formed the color filter for red (R), green (G), and blue (B). It is sectional drawing of the solid-state imaging device of the prior art example in which one pixel was formed in one island-like semiconductor. It is a top view of the solid-state imaging device of the prior art example which consists of an island-shaped semiconductor arranged in two dimensions. It is sectional drawing of the solid-state imaging device of the prior art example which formed the color filter for red (R), green (G), and blue (B). It is a cross-sectional structure diagram of a conventional solid-state imaging device capable of color imaging without forming red (R), green (G), and blue (B) color filters. The light absorption characteristics from the Si surface to the inside of the red (R), green (G), and blue (B) wavelength light in silicon (Si) are shown. 8A shows spectral sensitivity characteristics of red (R), green (G), and blue (B) signal outputs of the solid-state imaging device of FIG. 8A. It is a top view of the solid-state imaging device of FIG. 8A.

  Hereinafter, a solid-state imaging device according to an embodiment of the present invention and a method for manufacturing the solid-state imaging device will be described with reference to the drawings.

(First embodiment)
The solid-state imaging device according to the first embodiment of the present invention will be described below with reference to FIGS. 1A and 1B.
FIG. 1A shows a cross-sectional structure of the solid-state imaging device according to the present embodiment.
As shown in FIG. 1A, signal line N ⁺ regions 2a, 2b, and 2c are formed on a substrate 1. Island-like semiconductors H1, H2, and H3 are formed on the signal line N ⁺ regions 2a, 2b, and 2c. In the island-shaped semiconductors H1, H2, and H3, P regions 3a and 3b, which are mother semiconductor regions serving as a mother body constituting the island-shaped semiconductors H1, H2, and H3 so as to be connected to the signal lines N ⁺ regions 2a, 2b, and 2c. 3c is formed. Insulating layers 4a, 4b and 4c are formed on the outer periphery of P regions 3a, 3b and 3c, and insulating layers 4a, 4b and 4c are interposed, and conductor layer 5 is formed on the outer periphery of island-like semiconductors H1, H2 and H3. Has been.

The conductor layer 5 is formed so as to connect the island-shaped semiconductors H1, H2, and H3. N regions 6a, 6b, and 6c are formed on the outer peripheral portions of the P regions 3a, 3b, and 3c on the outer peripheral surface of the island-shaped semiconductors H1, H2, and H3 and above the upper end of the conductor layer 5. . P ⁺ regions 7a, 7b, and 7c are formed on the surface layers of the upper ends of the island-shaped semiconductors H1, H2, and H3 so as to contact the N regions 6a, 6b, and 6c and the P regions 3a, 3b, and 3c.

In the present embodiment, the height (thickness) of the P ⁺ regions 7a, 7b, and 7c in the island-shaped semiconductors H1, H2, and H3 is different from each other (in FIG. 1A, the thickness of the P ⁺ region 7a (here, light corresponds to the depth from the upper end surface layer of the island-like semiconductor H1, H2, H3 incident. hereinafter, ^{P +} region 7b, and also applies to such ^{P +} regions 7c.) is L7a, ^{P +} The thickness of the region 7b is L7b, and the thickness of the P ⁺ region 7c is L7c). Here, L7a is thinner than L7b, and L7b is thinner than L7c (L7a <L7b <L7c). All of the P ⁺ regions 7 a, 7 b and 7 c are connected to the pixel selection line conductor layer 8. A first interlayer insulating layer 9a is formed on the substrate 1 so as to surround the island-shaped semiconductors H1, H2, and H3. A conductor layer 5 is formed on the first interlayer insulating layer 9a, and a second interlayer insulating layer 9b is formed on the conductor layer 5 and the first interlayer insulating layer 9a. An overcoat insulating layer 9 c is formed on the second interlayer insulating layer 9 b and the pixel selection line conductor layer 8.

In the solid-state imaging device according to the present embodiment, photodiode regions 10a, 10b, and 10c are formed from P regions 3a, 3b, and 3c and N regions 6a, 6b, and 6c in the island-shaped semiconductors H1, H2, and H3. Yes. Here, when light enters from the P ⁺ regions 7a, 7b, 7c side of the upper surface layer of the island-shaped semiconductors H1, H2, H3, signal charges (here, in the photoelectric conversion regions of the photodiode regions 10a, 10b, 10c) Then, free electrons) are generated. The generated signal charges are accumulated mainly in the N regions 6a, 6b and 6c of the photodiode regions 10a, 10b and 10c.

Further, in the island-shaped semiconductors H1, H2, and H3, the N regions 6a, 6b, and 6c are gates, the P ⁺ regions 7a, 7b, and 7c are sources, the P regions 3a in the vicinity of the signal line N ⁺ regions 2a, 2b, and 2c, A junction field effect transistor having drains 3b and 3c is formed. In this solid-state imaging device, the drain-source current (output signal) of the junction field effect transistor changes according to the signal charge amount accumulated in the N regions 6a, 6b, 6c, and the signal line N ⁺ region 2a. 2b and 2c are taken out as signal outputs.

Further, in the island-shaped semiconductors H1, H2, and H3, the N regions 6a, 6b, and 6c of the photodiode regions 10a, 10b, and 10c are the source, the conductor layer 5 is the gate, and the signal line N ⁺ regions 2a, 2b, and 2c are A MOS transistor is formed using P regions 3a, 3b, 3c as channels between the drain and N regions 6a, 6b, 6c and the signal line N ⁺ regions 2a, 2b, 2c.

In this solid-state imaging device, the signal charges accumulated in the N regions 6a, 6b, and 6c are applied with a signal line N ⁺ by applying an on-voltage (high level voltage) to the conductor layer 5 that is the gate of the MOS transistor. The regions 2a, 2b and 2c are removed.

The cross section of the solid-state imaging device according to the present embodiment differs from the conventional solid-state imaging device shown in FIG. 7C in the following two points.
That is, one is that the RGB color filters (color filters B1, G1, R1) formed in the conventional solid-state imaging device are not formed in the solid-state imaging device according to the present embodiment. The other is that the P ⁺ regions 117a, 117b, and 117c have the same thickness in the solid-state imaging device of the conventional example, whereas the P ⁺ regions 7a, 7b, and 7c in the solid-state imaging device according to the present embodiment are the same. The thickness is different from each other.

When the island-shaped semiconductors H1, H2, and H3 are formed of silicon (Si), it is desirable to have the following dimensions and structure from FIG. 8B.
That is, referring to FIG. 1A, the thickness L7a of the P ⁺ region 7a is preferably 0.1 μm or less. The thickness L7b of the P ⁺ region 7b is preferably about 0.4 μm, and the thickness L7c of the P ⁺ region 7c is preferably about 1.2 μm. The height of the island-shaped semiconductors H1, H2, and H3 is preferably about 2 μm, and the height LG of the conductor layer 5 surrounding the island-shaped semiconductors H1, H2, and H3 is preferably 0.2 μm or less. The thickness of these components, the light transmission characteristics of the infrared cut filter provided on the front surface of the solid-state imaging device for obtaining a predetermined spectral sensitivity characteristics, or different depending on the color reproduction characteristics required.

Many holes are present in the P ⁺ regions 7a, 7b, and 7c. Therefore, ^{P +} regions 7a, 7b, of the incident light incident from the surface of the 7c, ^{P +} regions 7a, 7b, the signal charges generated by light absorbed in 7c (in this case free electrons), P ⁺ Recombination with many holes present in the regions 7a, 7b, 7c and disappear. For this reason, the P ⁺ regions 7a, 7b, and 7c are ineffective regions with respect to light sensitivity. On the other hand, in the island-shaped semiconductors H1, H2, and H3, photodiode regions 10a, 10b, and 10c are formed by the N regions 6a, 6b, and 6c and the P regions 3a, 3b, and 3c, and these photodiode regions 10a, 10b, 10c becomes a photoelectric conversion region. The signal charges generated in the photoelectric conversion region are accumulated mainly in the N regions 6a, 6b, and 6c.

Referring to FIG. 1, in island-shaped semiconductor H1, since thickness L7a of P ⁺ region 7a is 0.1 μm or less, photodiode region 10a formed by N region 6a and P region 3a is exposed from the surface of P ⁺ region 7a. A signal charge is generated mainly by incident blue (B), green (G), and red (R) wavelength light, and the signal charge is mainly accumulated in the N region 6a.

In the island-shaped semiconductor H2, ^{P +} for thickness L7b region 7 b is about 0.4 .mu.m, among the light incident from the surface of the ^{P +} region 7b, blue (B) wavelength light ^{P +} region 7b Absorbed in. For this reason, in the photodiode region 10b composed of the N region 6b and the P region 3b, signal charges mainly due to green (G) wavelength light and red (R) wavelength light are generated, and the generated signal charges are mainly generated in the N region 6b. Accumulated.

In the island-shaped semiconductor H3, since the thickness L7c of the P ⁺ region 7c is about 1.2 μm, the blue (B) wavelength light and the green (G) wavelength light are absorbed by the P ⁺ region 7c. For this reason, a signal charge mainly due to red (R) wavelength light incident from the surface of the P ⁺ region 7c is generated in the photodiode region 10c including the N region 6c and the P region 3c, and the generated signal charge is Accumulated mainly in the N region 6c. The signal charges accumulated in the N regions 6a, 6b and 6c are read out as signal currents from the signal line N ⁺ regions 2a, 2b and 2c by applying a high level voltage to the conductor layer 5.

The signal charge read from the signal line N ⁺ region 2b is mainly generated from the incident green (G) wavelength light and red (R) wavelength light, and the signal read from the signal line N ⁺ region 2c. The charge is mainly generated from incident red (R) wavelength light. Therefore, a green (G) signal is obtained by subtracting the signal current derived from the signal line N ⁺ region 2c from the signal current derived from the signal line N ⁺ region 2b by an external arithmetic circuit. The signal current read from the signal line N ⁺ region 2a is a signal generated mainly from incident red (R) wavelength light, green (G) wavelength light, and blue (B) wavelength light. For this reason, the green (G) signal and the red (R) signal obtained by the arithmetic processing described above, and the blue (B) wavelength light, the green (G) wavelength light, the red color read from the signal line N ⁺ region 2a are mainly used. The blue (B) signal can be obtained by subtracting the (R) wavelength light signal from an external circuit. Thereby, the island-shaped semiconductor H1 becomes a blue (B) pixel, the island-shaped semiconductor H2 becomes a green (G) pixel, and the island-shaped semiconductor H3 becomes a red (R) pixel. In this manner, the solid-state imaging device according to the present embodiment can perform color imaging without providing an RGB color filter.

  FIG. 1B is a plan view of the solid-state imaging device according to this embodiment in which pixels including the island-shaped semiconductors H1, H2, and H3 illustrated in FIG. 1A are two-dimensionally (matrix-shaped). A sectional view taken along one-dot chain line A-A ′ in FIG. 1B corresponds to FIG. 1A.

As shown in FIG. 1B, island-shaped semiconductors H11 to H33 are arranged two-dimensionally (H11 corresponds to H1, H12 in FIG. 1A, and H13 corresponds to H3 in FIG. 1A). The signal line N ⁺ regions 2a, 2b, and 2c are formed in a strip shape in the vertical direction. On the signal line N ⁺ region 2a, island-shaped semiconductors H11, H21, H31 of blue (B) pixels are arranged. Island-like semiconductors H12, H22, and H32 of green (G) pixels are arranged on the signal line N ⁺ region 2b. Island-like semiconductors H13, H23, and H33 of red (R) pixels are disposed on the signal line N ⁺ region 2c.

  The conductor layer 5a (corresponding to the conductor layer 5 in FIG. 1A), the conductor layer 5b, and the conductor layer 5c respectively surround the outer periphery of the island-shaped semiconductors H11 to H13, H21 to H23, and H31 to H33 arranged in the horizontal direction. In addition, these island-shaped semiconductors H11 to H13, H21 to H23, and H31 to H33 are formed so as to be connected to each other.

  In addition, island-shaped semiconductors H11 to H13 in which a pixel selection line conductor layer 8a (corresponding to the pixel selection line conductor layer 8 in FIG. 1A), a pixel selection line conductor layer 8b, and a pixel selection line conductor layer 8c are arranged in the horizontal direction, The outer peripheral portions of H21 to H23 and H31 to H33 are surrounded, and the island-shaped semiconductors H11 to H13, H21 to H23, and H31 to H33 are connected to each other.

  In the solid-state imaging device according to this embodiment, signal readout of the pixels H11 to H33 is performed by the same operation as that of the conventional solid-state imaging device shown in FIG. 7B. Thereby, this solid-state imaging device can perform color imaging without providing an RGB color filter on the island-shaped semiconductors H11 to H33.

In the solid-state imaging device according to this embodiment shown in FIG. 1B, the RGB color filters B1, B2, B3, R1, R2, R3, G1, G2, G3 required by the conventional solid-state imaging device shown in FIG. It becomes unnecessary. In the conventional solid-state imaging device shown in FIG. 7B, the RGB color filters B1, B2, B3, R1, R2, R3, G1, G2, and G3 are formed so as to surround the island-shaped semiconductors P11 to P33. In order to secure the upper mask alignment margin, it is necessary to provide a space between the island-shaped semiconductors P11 to P33.
On the other hand, in the solid-state imaging device according to the present embodiment, it is not necessary to secure such a manufacturing mask alignment margin, and accordingly, the space between the island-shaped semiconductors P11 to P33 can be reduced. it can. As a result, it is possible to increase the pixel density by increasing the density at which the island-shaped semiconductors H11 to H33 are formed, or to increase the sensitivity by increasing the diameter of the island-shaped semiconductors H11 to H33 itself.

  Further, the solid-state imaging device according to the present embodiment differs from the conventional solid-state imaging device shown in FIGS. 6, 7C, and 8A in that the wavelength light of blue (B), green (G), and red (R) is used. The white (W) wavelength signal including all of the above can be extracted from the island-shaped semiconductor H1 that is the blue (B) pixel. In the solid-state imaging device of the conventional example shown in FIGS. 6 and 7C, since RGB color filters are provided on each pixel, all the blue (B), green (G), and red (R) wavelength light is directly included. A white (W) wavelength signal cannot be obtained. 8A, the diode regions 126a, 126b, and 126c can obtain blue (B), green (G), and red (R) wavelength light signals independently from each other. , A white (W) wavelength signal cannot be obtained. In contrast, in the solid-state imaging device according to the present embodiment, the island-shaped semiconductor H1 is a blue (B) pixel and also functions as a white (W) pixel. As a result, a solid-state imaging device with high sensitivity and high dynamic range can be obtained. In the solid-state imaging device according to the present embodiment, the RGB color filter is not necessary, so that the cost can be reduced.

In the first embodiment shown in FIG. 1A, each RGB color signal is processed by processing signal currents from the signal line N ⁺ regions 2a, 2b, and 2c of the island-shaped semiconductors H1, H2, and H3 arranged in the horizontal direction. I got it. The arrangement of the P ⁺ regions (corresponding to the P ⁺ regions 7a, 7b, and 7c in FIG. 1A) of the upper surface portion of the island-shaped semiconductors H11 to H33 arranged in the vertical direction shown in FIG. 1B is not limited thereto. By doing so, the arrangement of the RGB pixels can be changed.

A color signal is obtained by arithmetic processing of signal currents from the island-shaped semiconductors H11 to H33 constituting the color pixels for the respective colors (red, green, and blue) arranged in the vertical direction. In this case, since the island-shaped semiconductors H11 to H33 arranged in the vertical direction are not the same color pixel, for example, a color imaging solid-state imaging device in which color pixels such as a Bayer type arrangement are arranged in a checkered pattern is obtained. As described above, in the solid-state imaging device according to the present embodiment, the arrangement of the P ⁺ regions (corresponding to the P ⁺ regions 7a, 7b, and 7c in FIG. 1A) on the top surface layer of the island-shaped semiconductors H11 to H33 is changed. Thus, a solid-state imaging device in which color pixels are arranged in a stripe shape or a checkered shape is realized.

In FIG. 1A, the signal line N ⁺ regions 2a, 2b, and 2c function as the drains of the junction field effect transistors and function as drains that remove the signal charges accumulated in the N regions 6a, 6b, and 6c. And have. The technical idea of the present invention is not limited to this, and the signal line N ⁺ regions 2a, 2b, and 2c are used to remove signal charges from the P ⁺ region as the signal line, the P region connected to the P ⁺ region, and the signal charges. The present invention can also be applied to a structure (for example, see Patent Document 4) that is a region formed of the N ⁺ region. That is, the signal line N ⁺ region may be configured by a plurality of semiconductor regions having a predetermined function. Such a configuration can also be applied to other embodiments of the present invention described below.

The technical idea of the present invention is a structure in which a P ⁺ region is provided on the outer periphery of the island-shaped semiconductors H1, H2, and H3 and between the N regions 6a, 6b, and 6c and the insulating layers 4a, 4b, and 4c ( For example, it is applicable also to patent documents 5 and 6). Such a configuration can also be applied to other embodiments of the present invention described below.

In the solid-state imaging device shown in FIG. 1A, the signal charge accumulated in the N regions 6a, 6b, 6c is applied to the signal line N by applying an on-voltage (high level voltage) to the conductor layer 5 that is the gate of the MOS transistor. ⁺ Removed in regions 2a, 2b, 2c. Performing However, removal of such signal charge is not to on-voltage (high voltage) is applied to the conductor layer 5, Shin Line N ⁺ regions 2a, 2b, by applying a high level voltage to 2c be able to. Such a configuration can also be applied to other embodiments of the present invention described below.

From the above, the following can be mentioned as basic matters for obtaining the effects of the technical idea of the present invention.
That is, on the top surface layer of the island-shaped semiconductors H1, H2, and H3, the source of the junction field effect transistor is generated, and the signal charges (free electrons) generated here disappear with recombination with holes. sufficiently high, including the concentration of the acceptor impurity P ⁺ regions 7a, 7b, it 7c are formed, also photodiode region for the P ⁺ region 7a, 7b, a photoelectric conversion and signal charge accumulated in the bottom of 7c to 10a, 10b and 10c are formed. Further, in the thicknesses L7a, L7b, and L7c in the island-like semiconductors H1, H2, and H3 of the P ⁺ regions 7a, 7b, and 7c, the thickness L7a of the P ⁺ region 7a is thinner than the thickness L7b of the P ⁺ region 7b. , The thickness L7b of the P ⁺ region 7b is thinner than the thickness L7c of the P ⁺ region 7c (L7a <L7b <L7c).

  2A to 2D show an example of a method for manufacturing the solid-state imaging device according to the first embodiment shown in FIG. 1A.

First, as shown in FIG. 2A, signal lines N ⁺ regions 2a, 2b, 2c are formed on the substrate 1, and island-like semiconductors H1, H2, H3 are formed on the signal line N ⁺ regions 2a, 2b, 2c. To do.

Subsequently, an insulating layer 9a is formed between the island-shaped semiconductors H1, H2, and H3 and on the substrate 1, and the insulating layers 4a , 4b, and 4c are formed on the outer peripheral portions of the island-shaped semiconductors H1, H2, and H3. Form.

Subsequently, the conductor layer 5 is formed on the outer periphery of the insulating layer 9a and the insulating layers 4a , 4b, and 4c of the island-shaped semiconductors H1, H2, and H3, and P of the island-shaped semiconductors H1, H2, and H3 on the conductor layer 5 is formed. For example, when the island-shaped semiconductors H1, H2, and H3 are silicon (Si), N regions 16a, 16b, and 16c are formed on the outer peripheral portions of the regions 3a, 3b, and 3c by arsenic (As) ion implantation.

Subsequently, an insulating layer 17 is formed on the conductor layer 5 between the insulating layer 9a and the island-shaped semiconductors H1, H2, and H3, and the insulating layer 17 and the island-shaped semiconductors H1 and H1 are formed by using, for example, CMP (Chemical Mechanical Polish). The heights of H2 and H3 are made equal to each other , the surfaces of the insulating layer 17 and the island-shaped semiconductors H1, H2, and H3 are flattened, and a thin insulating layer 18 is formed thereon. Further, a photoresist layer 19 having an opening is formed on the island-like semiconductor H3.

Subsequently, as shown in FIG. 2B, boron (B) ions, for example, acceptor impurities are implanted through the opening of the photoresist layer 19, and a P ⁺ region having a depth L7c is formed in the upper surface layer of the island-shaped semiconductor H3. 20c is formed. In this case, since the island-shaped semiconductors H1 and H2 are covered with the photoresist layer 19, boron (B) ions are not implanted into the island-shaped semiconductors H1 and H2. Thereafter, the photoresist layer 19 is removed.

Subsequently, as shown in FIG. 2C, a P ⁺ region 20b having a depth L7b is formed on the top surface layer of the island-shaped semiconductor H2 by a method similar to the method for forming the P ⁺ region 20c of the island-shaped semiconductor H3 described above. The photoresist layer is removed.

Subsequently, boron (B) ion implantation is performed on the entire surface layer of the insulating layer 18 to form a P ⁺ region 20a having a depth L7a on the upper surface portion of the island-shaped semiconductor H1. In this case, similarly to the island-shaped semiconductor H1, boron (B) ions are implanted into the surface layer portions of the island-shaped semiconductors H2 and H3 to the position indicated by the dotted line in FIG. 2C. However, ^{P +} region 20b, the 20c, already a large amount of boron (B) ions, because it is injected to a position deeper than the ^{P +} regions 20a, ^{the P +} region 20b, does not affect the electrical properties of 20c .

Subsequently, by performing heat treatment at about 1000 ° C., for example, donor impurities of arsenic (As) ions implanted in the N regions 16a, 16b, and 16c and boron ions implanted in the P ⁺ regions 20a, 20b, and 20c ( The acceptor impurity B) is activated and the insulating layer 18 is removed.

Subsequently, as shown in FIG. 2D , the insulating layer 17 and the insulating layers 4a, 4b, and 4c are removed from the outer peripheral portion of the top surface layer of the island-shaped semiconductors H1, H2, and H3, and P ^{+ is} formed on the insulating layer 17. The pixel selection line conductor layer 8 is formed so as to be connected to the regions 20a, 20b, and 20c.

Subsequently, an overcoat insulating layer 9 c is formed on the P ⁺ regions 20 a, 20 b, 20 c, the pixel selection line conductor layer 8, and the insulating layer 17. Thereby, the solid-state imaging device according to the first embodiment shown in FIG. 1A is manufactured.

(Second Embodiment)
The solid-state imaging device according to the second embodiment of the present invention will be described below with reference to FIGS. 3A to 3C.
FIG. 3A shows a cross-sectional structure diagram of the solid-state imaging device of the present embodiment.
Referring to FIG. 3A, pixel structures are formed in island-like semiconductors H1, H2, and H3 in the same manner as the solid-state imaging device of the first embodiment shown in FIG. 1A. An insulating layer 9 d is formed on the interlayer insulating layer 9 b and the pixel selection line conductor layer 8. The upper surface of the insulating layer 9d is planarized. Green (G) color filters 12 are formed on the island-like semiconductor H2 above及beauty insulation layer 9d. Overcoat insulating layer 9e is formed on the color filter 12 for insulation layer 9d and the green (G).

  In this embodiment, as in the first embodiment shown in FIG. 1A, the island-shaped semiconductor H1 is a blue (B) pixel, the island-shaped semiconductor H2 is a green (G) pixel, and the island-shaped semiconductor H3 is This is a red (R) pixel.

As shown in FIG. 3A, since the green (G) color filter 12 is formed on the island-like semiconductor H2 that is the green (G) pixel, the signal line N ⁺ region of the island-like semiconductor H3 shown in FIG. 1A. A green (G) signal can be obtained directly from the signal line N ⁺ region 2b without performing arithmetic processing with the signal from 2c. The red (R) signal is obtained directly from the island-shaped semiconductor H3, which is a red (R) pixel, as in FIG. 1A. The blue (B) signal is obtained by arithmetic processing of the signal from the island-shaped semiconductor H1 that is the blue (B) pixel and the already obtained green (G) signal and red (R) signal. Thereby, an RGB color signal is obtained.

  In color imaging, a green (G) signal is a main signal component of a luminance signal that represents the contour of an image, and is also an important signal component in color reproduction, so that a more accurate green (G) signal can be obtained. This means that a faithful luminance signal and color signal can be obtained. The solid-state imaging device according to the present embodiment requires the green (G) color filter 12. However, the solid-state imaging device is faithful to the light from the subject without using three RGB color filters as in the conventional solid-state imaging device. A solid-state imaging device for color imaging capable of obtaining a green (G) signal can be realized.

FIG. 3B shows a plan view of a solid-state imaging device in which the pixels shown in FIG. 3A are arranged two-dimensionally (matrix). FIG. 3A corresponds to a cross-sectional view taken along one-dot chain line BB ′ in FIG. 3B.
Green (G) color filters 12a, 12b, and 12c (green (G) color filter 12a corresponds to green (G) color filter 12 in FIG. 3A) are on island-like semiconductors H12, H22, and H32. The island-shaped semiconductors H12, H22, and H32 are formed so as to cover them.

The solid-state imaging device according to this embodiment is formed in the same manner as the solid-state imaging device shown in FIG. 1B except for the green (G) color filters 12a, 12b, and 12c. In this case, the green (G) color filters 12a, 12b, and 12c need a space for securing a mask alignment margin in manufacturing between the island-shaped semiconductors H12, H22, and H32. Unlike the conventional solid-state imaging device, the blue (B) color filter and the red (R) color filter are not required, so that, unlike the conventional solid-state imaging device, higher pixel density and lower cost are realized. .

  In the solid-state imaging device according to the present embodiment, since a green (G) signal is obtained directly, a red (R) signal obtained directly from the island-shaped semiconductors H13, H23, and H33, and the island-shaped semiconductors H11 and H21. By the arithmetic processing with the white (W) signal obtained from H31, a blue (B) signal faithful to the light from the subject can be obtained as compared with the solid-state imaging device according to the first embodiment. Thereby, compared with the solid-state imaging device according to the first embodiment, overall better color reproduction characteristics can be obtained. In addition, since the island-shaped semiconductors H11, H21, and H31 are blue (B) pixels and function as white (W) pixels, a solid-state imaging device having high sensitivity and a high dynamic range is realized.

FIG. 3C shows a cross-sectional structure diagram of a mode in which the blue (B) color filter 11 is formed on the island-shaped semiconductor H1 in the solid-state imaging device of the present embodiment. The pixel structures of the island-shaped semiconductors H1, H2, and H3 are formed by a manufacturing method similar to that of the solid-state imaging device of the first embodiment shown in FIG. 1A. An insulating layer 9 d is formed on the interlayer insulating layer 9 b and the pixel selection line conductor layer 8. The upper surface of the insulating layer 9d is planarized. The color filter 11 for blue (B) are formed in the island-like semiconductor H1及beauty insulation layer 9d. The overcoat insulating layer 9e is formed on the insulation layer 9d and blue (B) color filters 11.

In the solid-state imaging device according to the present embodiment, a blue (B) signal is obtained directly from the island-shaped semiconductor H1. Usually, of the light obtained from the subject, the blue (B) wavelength light reaches the photodiode region 10a, which is the photoelectric conversion region of the island-shaped semiconductor H1, as compared with the green (G) wavelength light and the red (R) wavelength light. By then, much more is lost due to reflection on each lens surface, island-like semiconductor H1 surface, and light absorption at the P ⁺ region 7a. For this reason, in imaging of a subject containing a large amount of blue (B) wavelength light component or imaging in a dark scene, better reproducibility of the blue (B) signal is required. On the other hand, in the solid-state imaging device according to the present embodiment, the blue (B) color filter 11 is required. However, unlike the conventional solid-state imaging device, the three RGB color filters are not used and the object can be detected from the subject. Thus, a blue (B) signal that is more faithful to the light of can be obtained.

  In the solid-state imaging device according to the present embodiment illustrated in FIG. 3C, a white (W) signal cannot be obtained directly from the independent island-shaped semiconductors H1, H2, and H3. In this case, an island-shaped semiconductor having a structure similar to that of the island-shaped semiconductor H1 not provided with the blue (B) color filter 11 is separated from the island-shaped semiconductor H1 provided with the blue (B) color filter 11. By forming adjacent to the semiconductors H1, H2, and H3, a white (W) signal can be obtained from the island-shaped semiconductor. In this case, although the number of island-shaped semiconductors formed in the pixel region increases, a blue (B) signal having high color reproducibility can be obtained, and high sensitivity and high dynamic range can be realized in the solid-state imaging device. .

  In addition, even if this embodiment is applied to the solid-state imaging device which forms the color filter for red (R) on the island-like semiconductor H3, the effect obtained is small. The reason is that in such a solid-state imaging device, the island-shaped semiconductor H3 can obtain a red (R) signal by itself. This is effective when a predetermined color filter is provided on the island-shaped semiconductor (in FIG. 1A, the island-shaped semiconductors H1 and H2 correspond) in order to obtain a plurality of color wavelength light component signals. Is obtained.

  In the present embodiment, the case where the primary color filter of the green (G) color filter 12 or the blue (B) color filter 11 is used has been described. However, the present invention is not limited to this, and the same effect can be obtained even when complementary color filters such as cyan (Cy) and magenta (Mg) are used. For example, when a cyan (Cy) color filter that transmits blue (B) wavelength light and red (R) wavelength light is provided on the island-shaped semiconductor H2, the signal output obtained from the island-shaped semiconductor H2 and the island-shaped semiconductor H3 A blue (B) signal output is obtained by arithmetic processing with the obtained red (R) signal output. Then, a green (G) signal output is obtained by calculating the obtained red (R) signal output, blue (B) signal output, and the signal output from the island-shaped semiconductor H1.

(Third embodiment)
The solid-state imaging device according to the third embodiment will be described below with reference to FIGS. 4A and 4B. This embodiment is a further improvement of the solid-state imaging device according to the second embodiment.
FIG. 4A shows a cross-sectional structure of the solid-state imaging device according to this embodiment. Island-like semiconductors H1, H2A, and H3 are formed on the signal line N ⁺ regions 2a, 2b, and 2c. A green (G) color filter 12 is formed on the island-shaped semiconductor H2A.

In this embodiment, the structure of the island-shaped semiconductors H1 and H3 is the same as that of the island-shaped semiconductors H1 and H3 shown in FIG. 3A. The island-shaped semiconductor H1 is for blue (B) signals, and the island-shaped semiconductor H3 is red ( R) For signals. However, the green (G) signal island-like semiconductor H2A has the same structure as the island-like semiconductor H1, which is different from the configuration shown in FIG. 3A. The thicknesses of the P ⁺ region 7bb and the N region 6bb are equal to the thicknesses of the P ⁺ region 7a and the N region 6a of the island-shaped semiconductor H1, respectively. Since the island-shaped semiconductor H2A on green (G) color filter 1 2 are formed, can be from the island-like semiconductor H2A obtain green (G) are signal directly. 3A, unlike the conventional solid-state imaging device, the blue (B) color filter and the red (R) color filter are not necessary. In comparison, higher pixel density can be realized. In addition, compared with the solid-state imaging device of the first embodiment, color reproduction characteristics that are further excellent overall can be obtained.

In the present embodiment, the island-shaped semiconductor H1 is a blue (B) pixel and can function as a white (W) pixel, thereby realizing a solid-state imaging device having high sensitivity and a high dynamic range. can do. As described above, the island-shaped semiconductor structure including the P ⁺ regions 7a and 7bb having the same thickness, the island-shaped semiconductors H1 and H2A, and the island-shaped semiconductor H3 having the P ⁺ region thicker than the P ⁺ regions 7a and 7bb. Thus, a solid-state imaging device having the same characteristics as in FIG. 3A can be realized. According to such a configuration, the step of forming the P ⁺ region 7b of the island-shaped semiconductor H2 in the solid-state imaging device shown in FIG. 3A becomes unnecessary, and the P ⁺ regions 7a and 7bb of the island-shaped semiconductors H1 and H2A are formed simultaneously. Therefore, the solid-state imaging device can be obtained at a lower cost than the solid-state imaging device of FIG. 3A.

  FIG. 4B is a structural cross-sectional view when the red (R) color filter 13 is formed on the island-shaped semiconductor H3A in the solid-state imaging device according to the present embodiment.

As shown in FIG. 4B, in the present embodiment, island-shaped semiconductors H1, H2, and H3A are formed on the signal line N ⁺ regions 2a, 2b, and 2c.
In this embodiment, the structures of the island-shaped semiconductors H1 and H2 are the same as the island-shaped semiconductors H1 and H2 shown in FIG. 3A. The island-shaped semiconductor H1 is for blue (B) signals, and the island-shaped semiconductor H2 is green ( G) For signals. However, the red (R) signal island-like semiconductor H3A has the same structure as the island-like semiconductor H1, which is different from the configuration shown in FIG. 3A. The thicknesses of the P ⁺ region 7cc and the N region 6cc are equal to the thicknesses of the P ⁺ region 7a and the N region 6a of the island-shaped semiconductor H1, respectively. Since the red (R) color filter 13 is formed on the island-shaped semiconductor H3A, a red (R) signal can be obtained directly from the island-shaped semiconductor H3A. As described above, a color solid-state imaging device having two structures of the island-shaped semiconductors H1 and H3A having the P ⁺ regions 7a and 7cc having the same thickness and the island-shaped semiconductor H2 having the P ⁺ region 7b thicker than the P ⁺ regions 7a and 7cc. realizable. Thereby, the step of forming the P ⁺ region 7c of the island-shaped semiconductor H3 in the solid-state imaging device shown in FIG. 3A becomes unnecessary, and the P ⁺ regions 7a and 7cc of the island-shaped semiconductors H1 and H3A can be formed simultaneously. Therefore, the solid-state imaging device can be obtained at a lower cost than the solid-state imaging device shown in FIG. 3A.

In addition, even if this embodiment is applied to the solid-state imaging device which forms the color filter for blue (B) on the island-like semiconductor H1, the effect obtained is small. The reason is that in such a solid-state imaging device, island-like semiconductors H1, H2, and H3 require P ⁺ regions 7a, 7b, and 7c having the same thickness as the solid-state imaging device shown in FIG. 1A. In the present embodiment, a solid-state imaging device in which predetermined color filters such as green and red are provided on island-like semiconductors (island-like semiconductors H2 and H3 in FIG. 1A) from which signals other than blue (B) signals can be obtained. The effect is obtained by applying to.

(Fourth embodiment)
Hereinafter, a solid-state imaging device according to a fourth embodiment of the present invention will be described with reference to FIG.
Referring to FIG. 5, insulating layer 20 that transmits light is formed on semiconductor substrate 1a that absorbs light. Thereafter, pixels are formed in the island-shaped semiconductors H1, H2, and H3 in the same manner as in the first embodiment shown in FIG. 1A.

In the solid-state imaging device according to the present embodiment, a part of the incident light beam 14a incident on the red (R) island-shaped semiconductor H3 and reaching the surface of the insulating layer 20 passes through the insulating layer 20 and passes through the semiconductor substrate 1a. It is divided into a light ray that enters the inside, a reflected light ray 14b reflected at the interface between the signal line N ⁺ region 2c and the insulating layer 20, and a reflected light ray 14c reflected at the interface between the semiconductor substrate 1a and the insulating layer 20. Among them, the reflected light 14b, a part of 14c reaches the photodiode region 10c is a photoelectric conversion region, and generates a signal charge. Here, due to the multiple reflection effect of the incident light beam 14a in the insulating layer 20 and the light absorption effect in the semiconductor substrate 1a, the intensity of the reflected light beams 14b and 14c is larger in the red (R) wavelength light than in the green (G) wavelength light. Thus, the thickness of the insulating layer 20 is set.

As shown in the light absorption intensity characteristic in the depth direction of the Si substrate of the light incident on the surface of the Si (silicon) substrate shown in FIG. 8B , the red (R) wavelength light (wavelength λ = 700 nm) is green ( G) It is absorbed in the Si substrate that is deeper than the wavelength light (wavelength λ = 550 nm). When the island-shaped semiconductors H1, H2, and H3 are formed of silicon (Si), the height of 2 μm of the island-shaped semiconductors H1, H2, and H3 is determined by the red (R) wavelength light absorption characteristics. Here, by increasing the intensity of the reflected rays 14b and 14c of the red (R) wavelength light, the height of the island-shaped semiconductors H1, H2, and H3 can be lowered without causing a decrease in sensitivity. Thus, by reducing the height of the island-shaped semiconductors H1, H2, and H3, manufacturing advantages such as easy processing of the conductor layer 5 formed on the bottom of the island-shaped semiconductors H1, H2, and H3 are obtained. It is done. When not changing the height of the island-like semiconductor H1, H 2, H3, by absorption of red (R) wavelength light in the photodiode region 10c is increased, sensitivity of the solid-state imaging device can be realized.

In the present embodiment, a transparent insulating layer is provided between the semiconductor substrate and the island-shaped semiconductor constituting the pixel, and the green (G) wavelength light or the red (R) wavelength light due to the multiple reflection effect on the transparent insulating layer. By using feedback to the island-shaped semiconductor, the height of the island-shaped semiconductor is reduced to facilitate the manufacturing method or increase the sensitivity (see, for example, Patent Document 3). In the first to third embodiments, since the P ⁺ region 7c is thick, the red (R) wavelength light absorbed in the P ⁺ region 7c does not contribute to the signal charge. As is clear from FIG. 8B, the degree of light absorption is higher at the upper part of the island-shaped semiconductor H3, and therefore, a sensitivity reduction due to light absorption of red (R) wavelength becomes a problem. On the other hand, according to the present embodiment, such a decrease in sensitivity is reduced.

In the above-described embodiment, the primary color type or complementary color type pixel arrangement is changed by changing the arrangement of the P ⁺ regions 7a, 7b, and 7c having different thicknesses on the top surface layer of the island- shaped semiconductors H11 to H33. The present invention can be applied to a checkered pattern such as a stripe pattern or a Bayer pattern. On the other hand, even if the island-shaped semiconductors themselves are arranged in a zigzag shape or a checkered shape, each island-shaped semiconductor can be caused to function as a predetermined color signal pixel by signal processing.

  In the first embodiment shown in FIG. 1A, the P regions 3a, 3b, and 3c are P regions, but may be intrinsic semiconductor regions that form diodes with the N regions 6a, 6b, and 6c. Such a configuration can be similarly applied to other embodiments of the present invention.

  Further, the substrate 1 in FIG. 1A may be an insulating layer or a semiconductor layer as long as pixels formed on the island-shaped semiconductors H1, H2, and H3 can perform a predetermined imaging operation.

In the first embodiment shown in FIG. 1A, the N ⁺ regions 2a, 2b, and 2c below the island-shaped semiconductors H1, H2, and H3 are signal lines, and the conductor layer 8 is connected to the P ⁺ regions 7a, 7b, and 7c above. Are the pixel selection lines, but the N ⁺ regions 2a, 2b, and 2c below the island-shaped semiconductors H1, H2, and H3 are the pixel selection lines, and the conductor layer 8 that is connected to the upper P ⁺ regions 7a, 7b, and 7c is the signal line. It is good. In this case, in the plan view shown in FIG. 1B, the conductor layers 8a, 8b, and 8c are formed in the vertical direction of the drawing, and the N ⁺ regions 2a, 2b, and 2c are formed in the horizontal direction, respectively. Such a configuration can be similarly applied to other embodiments of the present invention.

In FIG. 1A, the case of the signal line N ⁺ regions 2a, 2b, 2c, island-shaped semiconductor P regions 3a, 3b, 3c, diode N regions 6a, 6b, 6c, and P ⁺ regions 7a, 7b, 7c has been described. . However, the present invention is not limited to this, and the signal line P ⁺ regions 2a, 2b, 2c, diode P regions 6a, 6b, 6c, and N ⁺ regions 7a, 7b, 7c may be used. Such a configuration can be similarly applied to other embodiments of the present invention.

The pixel selection line conductor layer 8 may use a transparent (indium tin oxide) layer in addition to the metal material layer. In this case, the pixel selection line conductor layer may be formed so as to cover the surface of the P ⁺ region.

  It should be noted that the above embodiment can be variously modified and modified without departing from the broad spirit and scope of the present invention. Moreover, the said embodiment is for demonstrating one Example of this invention, and does not limit the scope of the present invention.

  The present invention can be widely applied to a solid-state imaging device for color imaging in which pixels are formed using island-shaped semiconductors.

1 Substrate 2a, 2b, 2c Signal line N ⁺ region H1, H2, H3, H11 to H33, H2A, H3A Island-like semiconductor 3a, 3b, 3c P region 4a, 4b, 4c Insulating layer 5, 5a, 5b, 5c Conductor Layer 6a, 6b, 6c, 16a, 16b, 16c N region 7a, 7b, 7c, 20a, 20b, 20c P ⁺ region 8, 8a, 8b, 8c Pixel selection line conductor layer 9a First interlayer insulating layer 9b, 17th Two-layer insulating layer 9c Overcoat insulating layer 10a, 10b, 10c, 10bb, 10cc Photodiode region 11 Blue (B) color filter 12, 12a, 12b, 12c Green (G) color filter 13 Red (R) color Filter 14a Incident light 14b, 14c Reflected light 18 Insulating layer 19 Photoresist layer 20 Insulating layer

Claims (8)

In a solid-state imaging device in which a plurality of pixels are formed of island-shaped semiconductors and are two-dimensionally arranged in a pixel region,
A first semiconductor region is formed on the substrate,
A base semiconductor region constituting the island-shaped semiconductor is formed on the first semiconductor region,
A second semiconductor region that forms the base semiconductor region and the diode region is formed on an outer periphery of the base semiconductor region that is separated from the first semiconductor region,
A third semiconductor region having a conductivity type opposite to the second semiconductor region is formed on the second semiconductor region so as to be in contact with the base semiconductor region,
In the third semiconductor region, incident light incident from the top surface of the island-shaped semiconductor is absorbed by the third semiconductor region, and signal charges generated thereby are recombined in the third semiconductor region to disappear. Contains a sufficient amount of acceptor or donor impurities to
The island-shaped semiconductor is formed including the third semiconductor region having at least two different thicknesses,
In the island-shaped semiconductor, the third island-shaped semiconductor having the thinnest third semiconductor region, or the second island-shaped semiconductor having the second thinnest third semiconductor region. A primary color type or complementary color type color filter is formed on the semiconductor region, and the light transmitted through the color filter is transmitted to the first island-shaped semiconductor or the second island-shaped semiconductor below the color filter. The light wavelength component that performs light absorption and signal charge accumulation in the diode region is included,
Imaging operation by the solid-state imaging device,
A photoelectric conversion operation that absorbs light incident from an upper surface of the island-shaped semiconductor and generates a signal charge in a diode region including the second semiconductor region and the base semiconductor region;
A signal charge accumulation operation for accumulating the generated signal charge in the diode region;
Junction field effect using either the first semiconductor region or the third semiconductor region as a source or drain, the second semiconductor region as a gate, and the base semiconductor region surrounded by the second semiconductor region as a channel A stored signal charge amount reading operation for detecting a signal charge amount stored in the diode region by detecting a source / drain current flowing in the transistor;
A signal charge removal operation for removing signal charges accumulated in the diode region in the first semiconductor region,
A solid-state imaging device. The first island-shaped semiconductor has the third semiconductor region that transmits blue wavelength light, green wavelength light, and red wavelength light that is incident from the top surface.
The second island-shaped semiconductor has the third semiconductor region that absorbs blue wavelength light incident from the top surface.
Incident from the island-like semiconductor of the upper end surface, further comprising a third island-shaped semiconductive body having said third semiconductor region which absorbs the blue wavelength light and the green wavelength,
The diode region of the first island-shaped semiconductor is photoelectrically converted from blue wavelength light, green wavelength light, and red wavelength light that is incident from the upper end surface of the first island-shaped semiconductor, and the photoelectrically converted signal charges. Accumulation and
The diode region of the second island-shaped semiconductor performs photoelectric conversion of green wavelength light and red wavelength light incident from the upper end surface of the second island-shaped semiconductor, and accumulation of the photoelectrically converted signal charge. ,
The diode region of the third island-shaped semiconductor is configured to perform photoelectric conversion of red wavelength light incident from the upper end surface of the third island-shaped semiconductor and accumulation of signal charges that have been photoelectrically converted.
The thickness of the third semiconductor region of the first island-shaped semiconductor is smaller than the thickness of the third semiconductor region of the second island-shaped semiconductor, and the thickness of the third semiconductor region of the second island-shaped semiconductor is the thickness of the third semiconductor region. Less than the thickness of the third semiconductor region of the third island-shaped semiconductor, and
The first island-shaped semiconductor, the second island-shaped semiconductor, and the third island-shaped semiconductor are formed adjacent to each other.
The solid-state imaging device according to claim 1.   Further, the primary color type or complementary color type color filter is formed on either the first island-shaped semiconductor or the second island-shaped semiconductor, and the color filter transmits the light transmitted through the color filter. The light wavelength component which performs light absorption and signal charge accumulation in the diode region in the first island-shaped semiconductor or the second island-shaped semiconductor located below is included. The solid-state imaging device described in 1.   In the pixel region, the first island-shaped semiconductor in which a color filter that transmits blue wavelength light is formed above, and the first island-shaped semiconductor in which the color filter that transmits blue wavelength light is not formed above, , And a white signal current including a blue wavelength light component, a green wavelength light component, and a red wavelength light component is obtained from the first island-shaped semiconductor that does not have a color filter that transmits the blue wavelength light formed thereon. The solid-state imaging device according to claim 1. The island-shaped semiconductor is
A fourth island-shaped semiconductor having a diode region that performs photoelectric conversion of blue wavelength light, green wavelength light, and red wavelength light that has been transmitted through the third semiconductor region, and accumulation of the photoelectrically converted signal charge;
A fifth island-shaped semiconductor having a diode region that performs photoelectric conversion of one or both of green wavelength light and red wavelength light that has passed through the third semiconductor region, and accumulation of the photoelectrically converted signal charge; And
A thickness of the third semiconductor region of the fifth island-shaped semiconductor is equal to or greater than a thickness of the third semiconductor region of the fourth island-shaped semiconductor;
A sixth island-shaped semiconductor having a structure similar to that of the second semiconductor region and the third semiconductor region in the fourth island-shaped semiconductor and the fifth island-shaped semiconductor is formed in the pixel region,
A primary color type or a complementary color type color filter is formed on the sixth island-shaped semiconductor,
The fourth island-shaped semiconductor, the fifth island-shaped semiconductor, and the sixth island-shaped semiconductor are formed adjacent to each other.
The solid-state imaging device according to claim 1. The island-shaped semiconductor is
A seventh island-shaped semiconductor having a diode region that performs photoelectric conversion of blue wavelength light, green wavelength light, and red wavelength light transmitted through the third semiconductor region, and accumulation of signal charges obtained by the photoelectric conversion;
An eighth island-shaped semiconductor having a diode region that performs photoelectric conversion of green wavelength light and red wavelength light transmitted through the third semiconductor region and accumulation of the photoelectrically converted signal charge;
A thickness of the third semiconductor region of the eighth island-shaped semiconductor is formed to be greater than a thickness of the third semiconductor region of the seventh island-shaped semiconductor;
A ninth island shape having a second semiconductor region and a third semiconductor region having the same structure as the second semiconductor region and the third semiconductor region in the seventh island shape semiconductor and the eighth island shape semiconductor in the pixel region. A semiconductor is formed,
A primary color type or complementary color type color filter is formed on the ninth island-shaped semiconductor,
The seventh island-shaped semiconductor, the eighth island-shaped semiconductor, and the ninth island-shaped semiconductor are formed adjacent to each other.
The solid-state imaging device according to claim 1.   An insulating layer that transmits light is formed between the substrate and the first semiconductor region, and the insulating layer has a thickness from the insulating layer out of the rays incident from the top surface of the island-shaped semiconductor. 2. The solid-state imaging device according to claim 1, wherein a red wavelength component of light rays returning to the diode region of the island-shaped semiconductor is set to be larger than a green wavelength component.   2. The solid-state imaging device according to claim 1, wherein in the pixel region, the island-shaped semiconductors having at least two different thicknesses are arranged in a zigzag shape or a checkered shape in the third semiconductor region. .

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