TW201417324A - Solid-state imaging device - Google Patents

Abstract

In a solid-state imaging device, N regions (6a, 6b, 6c) serving as photoelectric conversion diodes are formed at peripheral portions of P regions (3a, 3b, 3c) that are formed are at upper parts in island semiconductor (H1, H2, H3) on a substrate (1). P+ regions (7a, 7b, 7c), connected to a pixel selection line conductive layer (8), are formed on surface portions of the upper end parts of the island semiconductor (H1, H2, H3) in a manner that the N regions (6a, 6b, 6c) are closely adjacent to the P regions (3a, 3b, 3c). The thickness of the P+ region (7a) is thinner than that of the P+ region (7b), and the thickness of P+ region (7b) is thinner than that of the P+ region (7c).

Description

Solid state photography device

The present invention relates to a solid-state imaging device, and more particularly to an image forming device using an island-shaped semiconductor (columnar semiconductor), thereby realizing high pixel density, high sensitivity, and high dynamic range. A solid-state imaging device for color photography.

A solid-state imaging device for color photography such as a charge coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS) type is often used for a video camera, a still camera, or the like. in. Further, in these applications, performance improvement such as high pixel density, high sensitivity, and high dynamic range of a solid-state imaging device for color photography has been sought.

Fig. 6 is a cross-sectional structural view showing a conventional CMOS type color solid-state imaging device (see, for example, Patent Document 1).

In the P region (hereinafter, a P-type semiconductor region including an acceptor impurity is represented by a "P region") 矽 (hereinafter, referred to as "Si"), the surface of the substrate 100 is oxidized by local enthalpy (Local) The Oxidation of Silicon (LOCOS) method forms a cerium oxide layer (hereinafter referred to as SiO ₂ layer) 101a for separation and a cerium oxide layer 101d for separation. An N region is formed between the separation SiO ₂ layer 101a to the separation SiO ₂ layer 101d (hereinafter, an N-type semiconductor region including donor impurities is represented by "N region") 102a to N. Area 102c.

In FIG. 6, a photodiode of a PN junction is formed by the P region substrate 100 and the N regions 102a to N regions 102c. Incident light (electromagnetic energy wave) incident from the upper surface of the N region 102a to the N region 102c is photoelectrically converted in the N region 102a to the N region 102c and the P region substrate 100 below it, thereby generating signal charges (in this case) For free electronics). The generated signal charge is stored in the photodiode and taken out as a signal output current for a predetermined period of time and taken out to an externally disposed output circuit.

An interlayer SiO ₂ layer 103 is formed on the separation SiO ₂ layer 101a to the separation SiO ₂ layer 101d and the N region 102a to N region 102c. Metal wirings 104a to 104d are formed on the interlayer SiO ₂ layer 103. Further, a protective insulating layer 105 containing, for example, SiO ₂ or an organic material layer is formed on the interlayer SiO ₂ layer 103 and the metal wiring 104a to the metal wiring 104d.

In Fig. 6, the upper surface of the protective insulating layer 105 is flattened. In the protective insulating layer 105, a red (R) color filter 106R and green are disposed so as to surround the N region 102a to the N region 102c in which the photodiode is formed in a direction perpendicular to the upper surface. G) The color filter 106G and the blue (B) color filter 106B are used. Moreover, in red (R) color filter 106R, green The separation insulating layer 107a to the isolation insulating layer 107c are formed between the color filter (G) color filter 106G and the blue (B) color filter 106B.

Among the incident light incident from the upper surface of the N region 102a to the N region 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 referred to as "color filter 106R"), green (G) color filter 106G (hereinafter referred to as "color filter 106G"), blue (B) The color filter 106B (hereinafter simply referred to as "color filter 106B") is formed of a photoresist containing a pigment or a dye. The green (G) color filter 106G is formed by a photolithography technique, and the protective insulating layer 105 and the color filter 106G are covered by the separation insulating layer 107a. The color filter 106R and the color filter 106B are formed on the separation insulating layer 107a by photolithography. The insulating layer for separation 107c also functions as a protective layer of the color filter 106R, the color filter 106G, and the color filter 106B.

The separation SiO ₂ layer 101a, the separation SiO ₂ layer 101d, the N regions 102a to N region 102c, and the metal wiring 104a to the metal wiring 104d formed on the P region substrate 100 shown in FIG. 6 are provided by a microprocessor and a memory. The microfabrication technology used in the above is formed by the cutting-edge CMOS microfabrication technology. Although not shown in FIG. 6, the SiO ₂ layer 101a to the separation SiO ₂ layer 101d, the N region 102a to the N region 102c, and the metal wiring 104a to the metal wiring 104d are similarly applied to the P region substrate 100. A CMOS transistor for forming a driving circuit, a signal processing circuit, or the like is formed by the tip CMOS microfabrication technique.

On the other hand, the tip CMOS microfabrication technique cannot be used in the color filter 106R, the color filter 106G, and the color filter 106B, but is formed by a photolithography technique using a photoresist material different therefrom.

The refineable size (minimum processing size) of the color filter 106R, the color filter 106G, and the color filter 106B using the photolithography technique is coarser than the refineable size by the above-described tip CMOS microfabrication technique ( Big). As described above, in the color filter 106R, the color filter 106G, and the color filter 106B, the microfabrication technique cannot be applied, which hinders the further high pixel density of the CMOS solid-state imaging device.

Further, the processes and devices for forming the color filter 106R, the color filter 106G, and the color filter 106B are different from the processes and devices used in the above-described tip CMOS microfabrication technology, which causes a cost increase. This has become a problem for realizing cost reduction of the solid-state imaging device.

Further, since the color filter 106R, the color filter 106G, and the color filter 106B themselves cause light absorption, in the color filter 106R, 100% light transmittance cannot be achieved in the red (R) wavelength region. Similarly, in the color filter 106G and the color filter 106B, light transmittance of 100% in the green (G) wavelength region and the blue (B) wavelength region cannot be achieved. As a result, the light absorption which hinders the improvement of the light transmittance of the color filter 106R, the color filter 106G, and the color filter 106B hinders the sensitivity of the CMOS type color solid-state imaging device.

Hereinafter, a solid-state imaging device for color photography according to another conventional example will be described with reference to FIGS. 7A to 7C.

FIG. 7A is a cross-sectional structural view showing a solid-state imaging device that constitutes one pixel in one island-shaped semiconductor (see, for example, Patent Document 2).

Referring to Fig. 7A, a signal line N ⁺ region 112 is formed on the substrate 111 (hereinafter, a semiconductor region containing a plurality of donor impurities is referred to as "N ⁺ region"). An island-shaped semiconductor 110 is formed on the signal line N ⁺ region 112. An insulating layer 114 is formed on the outer peripheral portion of the P region 113 connected to the signal line N ⁺ region 112 in the island-shaped semiconductor 110, and the conductor layer 115 is formed via the insulating layer 114. An N region 116 is formed on the outer peripheral portion of the P region 113 above the conductor layer 115. In the N region 116 and the P region 113, a P ⁺ region (hereinafter, a semiconductor region containing a plurality 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 layer 114 is connected to each other in a state of surrounding the outer peripheral portion of the island-shaped semiconductor 110. Similarly to the insulating layer 114, the conductor layer 115 is also connected to each other in a state of surrounding the outer peripheral portion of the island-shaped semiconductor 110.

In the solid-state imaging device, in the island-shaped semiconductor 110, a photodiode region 119 is formed by the P region 113 and the N region 116. Here, when light is incident from the P ⁺ region 117 side of the upper end portion of the island-shaped semiconductor 110, a signal charge (here, free electron) is generated in the photoelectric conversion region in the photodiode region 119. Moreover, the generated signal charge is mainly stored in the N region 116 of the photodiode region 119.

Further, a junction field-effect transistor is formed in the island-shaped semiconductor 110, and the junction field effect transistor uses the N region 116 as a gate and the P ⁺ region 117 as a source, a signal. The P region 113 near the line N ⁺ region 112 serves as a drain.

In the solid-state imaging device, the drain-source current (output signal) of the junction field effect transistor changes according to the amount of signal charge stored in the N region 116, and is output as a signal from the signal line N ⁺ region 112. take out.

Further, a metal oxide semiconductor (MOS) transistor is formed in the island-shaped semiconductor 110, and the MOS transistor uses the N region 116 of the photodiode region 119 as a source, and the conductor layer 115 serves as a source The gate, the signal line N ⁺ region 112 serves as a drain, and the P region 113 between the N region 116 and the signal line N ⁺ region 112 serves as a channel.

In the solid-state imaging device, signal charges stored in the N region 116 are removed in the signal line N ⁺ region 112 by applying a turn-on voltage (high level voltage) to the conductor layer 115 which is a gate of the MOS transistor.

In addition, in the present specification, the "high level voltage" indicates a higher level positive voltage when the signal charge is free electrons, and the "low level voltage" means a lower absolute value than the "high level voltage". Voltage. Therefore, when the signal charge is a hole, the "high level voltage" means a lower level negative voltage, and the "low level level voltage" means a voltage closer to 0V than the "high level level voltage".

In the imaging operation of the solid-state imaging device, the following operations (1) to (3) are included in a state where a ground voltage (=0 V) is applied to the signal line N ⁺ region 112, the conductor layer 115, and the P ⁺ region 117.

(1) a signal charge storing operation for storing signal charges generated in the photoelectric conversion region (photodiode region 119) by incident light from the surface layer of the upper end portion of the island-shaped semiconductor 110 in the N region 116;

(2) Signal charge reading operation, in a state where a ground voltage is applied to the signal line N ⁺ region 112 and the conductor layer 115, and a positive voltage is applied to the P ⁺ region 117, the N is changed by the amount of stored signal charge. The source drain current of the junction field effect transistor modulated by the potential of the region 116 is read as a signal current;

(3) The reset operation, after the signal charge reading operation, is applied to the N region in a state where 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. The signal charge of 116 is removed in the signal line N ⁺ region 112.

FIG. 7B is a plan view showing a solid-state imaging device of a conventional example in which the island-shaped semiconductor P11 to the island-shaped semiconductor P33 (corresponding to the island-shaped semiconductor 110 in FIG. 7A) constituting a pixel are arranged in a two-dimensional matrix. An island-shaped semiconductor P11 to island constituting a pixel is formed on the signal line N ⁺ region 112a, the signal line N ⁺ region 112b, and the signal line N ⁺ region 112c (corresponding to the signal line N ⁺ region 112 in FIG. 7A). Semiconductor P33.

In the island-shaped semiconductor P11 to the island-shaped semiconductor P33, in the horizontal direction On each of the extended columns, the pixel selection line conductor layer 118a, the pixel selection line conductor layer 118b, and the pixel selection line conductor layer 118c (corresponding to the pixel selection line conductor layer 118 shown in Fig. 7A) are connected to each other. Formed by the way. Similarly, in the island-shaped semiconductor P11 to the island-shaped semiconductor P33 constituting the pixel, each column extending in the horizontal direction The conductor layer 115a, the conductor layer 115b, and the conductor layer 115c (corresponding to the conductor layer 115 in FIG. 7A) are formed to be connected to each other.

Further, blue is formed on the island-shaped semiconductor P11 to the island-shaped semiconductor P33. Color (B) color filter B1, blue (B) color filter B2, blue (B) color filter B3, red (R) color filter R1, red (R) Color filter R2, red (R) color filter R3, green (G) color filter G1, green (G) color filter G2, green (G) color filter G3.

According to the above configuration, the island-shaped semiconductor P11, the island-shaped semiconductor P21, The pixel of the island-shaped semiconductor P31 obtains a blue (B) signal current, and a green (G) signal current is obtained from the pixels of the island-shaped semiconductor P12, the island-shaped semiconductor P22, and the island-shaped semiconductor P32, and is formed by the island-shaped semiconductor P13 and the island shape. The pixel of the semiconductor P23 and the island-shaped semiconductor P33 obtains a red (R) signal current.

In the configuration shown in FIG. 7B, in order to ensure color formation for enclosing Sheet B1, color filter B2, color filter B3, color filter R1, color filter R2, color filter R3, color filter G1, color filter G2, color filter G3 The mask alignment margin required for manufacturing of the island-shaped semiconductor P11 to the island-shaped semiconductor P33 requires a space between the island-shaped semiconductors P11 and the island-shaped semiconductors P33. Thereby, the density of pixels is limited. Further, in the solid-state imaging device of the prior art, as in the solid-state imaging device shown in FIG. 6, the color filter B1, the color filter B2, the color filter B3, the color filter R1, and the color filter are colored. Film R2, color filter R3, color filter G1, color filter The light absorption in the light sheet G2 and the color filter G3 becomes a hindrance factor in achieving high sensitivity.

Fig. 7C shows a cross-sectional structural view taken along line CC' of Fig. 7B.

Referring to FIG. 7C, a signal line N ⁺ region 112a, a signal line N ⁺ region 112b, and a signal line N ⁺ region 112c are formed on the substrate 111a, in the signal line N ⁺ region 112a, the signal line N ⁺ region 112b, and the signal line N ⁺ An island-shaped semiconductor P11, an island-shaped semiconductor P12, and an island-shaped semiconductor P13 are formed on the region 112c. An insulating layer 120a is formed between the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island-shaped semiconductor P13, and on the substrate 111a, and the signal line N ⁺ region of the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island-shaped semiconductor P13 The outer peripheral portion of the P region 113a, the P region 113b, and the P region 113c to which the signal line N ⁺ region 112b and the signal line N ⁺ region 112c are connected is formed with the conductor layer 115a via the insulating layer 114a, the insulating layer 114b, and the insulating layer 114c. . The conductor layer 115a is formed such that the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island-shaped semiconductor P13 are connected to each other, and the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island located above the upper end of the conductor layer 115a. In the outer peripheral portion of the semiconductor P13, the N region 116a, the N region 116b, and the N region 116c of the photodiode are formed. An insulating layer 120b is formed between the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island-shaped semiconductor P13, and on the conductor layer 115a and the insulating layer 120a, at the upper ends of the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island-shaped semiconductor P13. The P ⁺ region 117a, the P ⁺ region 117b, and the P ⁺ region 117c are formed in the surface layer. A pixel selection line conductor layer 118a is formed on the insulating layer 120b so as to be connected to the P ⁺ region 117a, the P ⁺ region 117b, and the P ⁺ region 117c. An insulating layer 120c is formed on the insulating layer 120b, the pixel selection line conductor layer 118a, the P ⁺ region 117a, the P ⁺ region 117b, and the P ⁺ region 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. A protective layer insulating layer 120d is formed on the color filter B1, the color filter G1, the color filter R1, and the insulating layer 120c. The color filter B1, the color filter G1, and the color filter R1 are different from the microfabrication technique used in the pixel structure of the island-shaped semiconductor P11, the island-shaped semiconductor P12, and the island-shaped semiconductor P13. Since it is formed by the same manufacturing method as the solid-state imaging device shown in FIG. 6, there is a problem that the integration of pixels is high and the cost is reduced.

Hereinafter, while the color filter is not used, referring to FIGS. 8A to 8D A solid-state imaging device of another conventional example in which color photography can be performed will be described.

A cross-sectional structural view of the solid-state imaging device is shown in Fig. 8A (for example, reference) Patent Document 3).

Referring to FIG. 8A, 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. Here, the N region 124 is formed in the P region 123. The diode including the P region substrate 121 and the N region 122, the diode including the N region 122 and the P region 123, and the diode including 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 preferably about 0.6 μm from the surface of the P region substrate 121, and the N region 122 The depth is preferably about 2 μm from the surface of the P-region substrate 121.

Among the incident light incident from the surface of the P-region substrate 121, mainly blue (B) The light of the wavelength is photoelectrically converted in the diode region 126a (the region surrounded by the broken line in Fig. 8A) including the P region 123 and the N region 124, and the generated signal charges are stored in the diode region 126a. The light of the main green (G) wavelength is photoelectrically converted in the diode region 126b (the region surrounded by the broken line in FIG. 8A) including the P region 123 and the N region 122, and the generated signal charges are stored in the diode region 126b. in. Further, the light of the main red (R) wavelength is photoelectrically converted in the diode region 126c (the region surrounded by the broken line in FIG. 8A) including the P region substrate 121 and the N region 122, and the generated signal charges are stored in the diode. In the body region 126b.

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

The solid-state imaging device shown in FIG. 8A can be performed without using a color filter. The color photography is due to the use of the light absorption characteristics of the semiconductor (in this case, yttrium (Si)) shown in Fig. 8B.

As shown in FIG. 8B, blue (B) wavelength light (λ = 400 nm) is largely absorbed near the surface of Si (矽), green (G) wavelength light (λ = 550 nm), red (R) wavelength light (λ = The larger the 700 nm) and the wavelength (λ), the more light can be absorbed into the interior of Si (矽). Thereby, the main blue (B) signal is obtained from the diode region 126a, the main green (G) signal is obtained from the diode region 126b, and the main red (R) signal is obtained from the diode region 126c.

The wavelength (λ) dependence of the output of the output obtained from the ammeter 125a, the ammeter 125b, and the ammeter 125c is shown in Fig. 8C.

As shown in FIG. 8C, the blue (B) signal output VB from the ammeter 125a mainly has a blue (B) wavelength light output component, and the green (G) signal output VG from the ammeter 125b mainly has a green (G) wavelength. The light output component, the red (R) signal output VR from the galvanometer 125c, has primarily a red (R) wavelength light output component. By performing signal calculation processing such as white balance (White Balance) on the signal output VB, the signal output VG, and the signal output VR, a predetermined RGB signal is obtained.

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

The N region 124 is connected to the output circuit 129a (the region surrounded by the broken line in Fig. 8D) via the contact hole 127a and the lead wire 128a connected to the contact hole 127a. The P region 123 is connected to the output circuit 129b (the region surrounded by the broken line in Fig. 8D) via the contact hole 127b and the lead wire 128b connected to the contact hole 127b. The N region 122 is connected to the output circuit 129c (the region surrounded by the broken line in Fig. 8D) via the contact hole 127c and the lead wire 128c connected to the contact hole 127c.

The output circuit 129a, the output circuit 129b, and the output circuit 129c respectively include: An amplifier MOS transistor Am for detecting voltages of the N region 124, the P region 123, and the N region 122, a MOS transistor RS for row selection, and a diode region 126a, a diode region to be stored in the diode region 126b, resetting the MOS transistor Re of the signal charge removal of the diode region 126c. Here, the blue (B) signal is read from the blue (B) signal line 130a, the green (G) signal is read from the green (G) signal line 130b, and the red (R) signal is used from the red (R) signal. The signal line 130c is read. The output circuit 129a, the output circuit 129b, and the output circuit 129c 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 and the solid-state camera shown in FIG. Compared with the shadow device, it has the following advantages: color photography can be performed without using a color filter, and the diode region 126a, the diode region 126b, and the diode region 126c that perform photoelectric conversion of RGB wavelength light are in the depth direction. Formed by overlapping.

However, in the solid-state imaging device, blue receiving the maximum light receiving area is received The N region 124 of the color (B) wavelength light is formed inside the P region 123 and the N region 122, and thus the pixel size is increased when a predetermined blue (B) wavelength light sensitivity is obtained. Further, there is a problem that a signal including white (W) wavelength light of all 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, the color filter is provided independently of The pixels of 106B, the color filter 106G, and the color filter 106R form a new one in which the color filter 106B, the color filter 106G, and the color filter 106R are not provided. In the pixel, a white (W) wavelength light signal is obtained from the pixel, whereby high sensitivity or high dynamic range can be achieved (for example, refer to Non-Patent Document 1 and Non-Patent Document 2).

According to this technique, the following aspect is used: a white (W) pixel can read a large signal current compared to other RGB pixels, thereby obtaining a high SN ratio (signal/noise ratio). On the other hand, in the solid-state imaging device shown in Fig. 8A, the signal current of the white (W) wavelength light cannot be directly read.

Prior art literature

Patent literature

Patent Document 1: US Patent Application Publication No. 2005/0082627

Patent Document 2: US Patent Application Publication No. 2010/0200731

Patent Document 3: US Patent Application Publication No. 2012/104478

Patent Document 4: US Patent Application Publication No. 2012/0025281

Patent Document 5: US Patent Application Publication No. 2011/0215381

Patent Document 6: US Patent Application Publication No. 2011/0220969

Non-patent literature

Non-Patent Document 1: H. Bento, Y. Iida, Y. Jiangchuan, H. Zhengxi; "The growth of low-light signal noise ratio of a color CMOS imager with a 4x4 white-RGB color filter array "Journal of Electronic Components III (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)

Non-Patent Document 2: Y. Jiangchuan, N. Tanaka, N. Hehe, H. Zhengxi, A. Nakano, H. Bendo, Y. Iida, M. Wujing: "White-RGB Verification with Wide Dynamic Range Conformatory Factor Analysis (CFA) CMOS Image Sensor", International Solid-State Circuits Conference (ISSCC) 2008, Technical Paper Abstract (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) The solid-state imaging device of the prior art shown in FIG. 6 and FIG. 7C is formed in the color filter 106B, the color filter 106G, the color filter 106R, the color filter B1, and the color filter G1. The pixel structure of the lower portion of the color filter R1 is formed using a tip CMOS microfabrication technique.

On the other hand, color filter 106B, color filter 106G, color filter The light sheet 106R, the color filter B1, the color filter G1, and the color filter R1 cannot be formed using the CMOS microfabrication technique, but by a photolithography technique using a photoresist material different therefrom.

Therefore, the color filter 106B, the color filter 106G, and the color filter The fine processing size of the 106R, the color filter B1, the color filter G1, and the color filter R1 is larger (larger) than the fine processing size by the tip CMOS microfabrication technique. Therefore, the micro-processing technique of the color filter 106B, the color filter 106G, the color filter 106R, the color filter B1, the color filter G1, and the color filter R1 Further high pixel density of CMOS solid-state imaging devices is limited.

Furthermore, the process for forming the color filter 106B, the color filter 106G, the color filter 106R, the color filter B1, the color filter G1, and the color filter R1, the device and the tip CMOS microfabrication The processes and devices used in the technology are different, which causes a cost increase. This has become a problem for realizing cost reduction of the solid-state imaging device.

Further, R of the solid-state imaging device of the prior art shown in FIGS. 6 and 7C G, B color filter 106R, color filter 106G, color filter 106B, color filter B1, color filter G1, color filter R1 cause light absorption due to the material itself, so for color filter The sheet 106R and the color filter R1 cannot achieve 100% light transmittance in the red (R) wavelength region. Similarly, for the color filter 106G, the color filter G1, the blue (B) color filter 106B, and the color filter B1, the green (G) wavelength region and the blue color cannot be realized ( B) 100% light transmittance in the wavelength region. Thus, light absorption of the light transmittance of the color filter 106R, the color filter 106G, the color filter 106B, the color filter B1, the color filter G1, and the color filter R1 is hindered, and the CMOS is hindered. The color solid-state imaging device is highly sensitive.

Moreover, in the solid-state imaging device of the prior art shown in FIG. 8A, RGB is used. The diode region 126a, the diode region 126b, and the diode region 126c for photoelectric conversion of the wavelength light are formed to overlap in the depth direction, and the N region 124 of the blue (B) wavelength light that receives the largest light receiving area is formed. It is inside the P area 123 and the N area 122. Therefore, if you want to obtain the specified blue (B) wavelength light sensitivity, then the pixel The size will increase. Further, since it is not possible to directly obtain a signal of white (W) wavelength light including all blue (B) wavelength light, green (G) wavelength light, and red (R) wavelength light, it is impossible to realize the use of white (W) wavelength. High sensitivity of optical signals and high dynamic range.

In the solid-state imaging device for color photography according to the present invention, the plurality of pixels include island-shaped semiconductors, and the pixel regions 2 are arranged in a row, and the solid-state imaging device is characterized in that a first semiconductor region is formed on the substrate. a mother semiconductor region constituting the island-shaped semiconductor is formed on the first semiconductor region, and a second semiconductor region is formed on an outer peripheral portion of the mother semiconductor region spaced apart from the first semiconductor region, and the second semiconductor region forms the matrix In the semiconductor region and the diode, a third semiconductor region having a conductivity type opposite to the second semiconductor region is formed on the upper portion of the second semiconductor region so as to be in contact with the mother semiconductor region, and the third semiconductor The region includes an acceptor impurity or a donor impurity sufficient to re-couple the signal charge in the third semiconductor region, and the signal charge is incident on the third semiconductor from the upper end surface of the island-shaped semiconductor. The area semiconductor is generated, and the island semiconductor includes at least two of the above-mentioned first layers having different thicknesses 3 semi-guide The imaging operation of the solid-state imaging device includes a photoelectric conversion operation, and absorbs light incident from a surface of an upper end portion of the island-shaped semiconductor in a diode region including the second semiconductor region and the parent semiconductor region a signal charge is generated; a signal charge storage operation stores the generated signal charge in the diode region; and a signal charge amount reading operation is performed to detect a source drain current flowing through the junction field effect transistor And detecting the amount of signal charge stored in the diode region, wherein the junction field effect transistor uses any one of the first semiconductor region and the third semiconductor region as a source or a drain, The semiconductor region serves as a gate, and the mother semiconductor region surrounded by the second semiconductor region serves as a channel, and a signal charge removing operation removes signal charges stored in the diode region in the first semiconductor region.

Preferably, the plurality of island-shaped semiconductors include at least a first island-shaped semiconductor, and the third semiconductor layer having blue wavelength light, green wavelength light, and red wavelength light incident from an upper end surface of the island-shaped semiconductor a second island-shaped semiconductor having the third semiconductor layer that absorbs blue wavelength light incident from the upper end surface of the island-shaped semiconductor; and a third island-shaped semiconductor having an absorption from the upper end surface of the island-shaped semiconductor The third semiconductor layer of the blue wavelength light and the green wavelength light, The diode region of the first island-shaped semiconductor performs photoelectric conversion of blue wavelength light, green wavelength light, and red wavelength light incident from a surface of an upper end portion of the first island-shaped semiconductor, and a signal charge via the photoelectric conversion In the storage, 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 storage of signal charges by the photoelectric conversion The diode region of the third island-shaped semiconductor performs photoelectric conversion of red wavelength light incident from a surface of an upper end portion of the third island-shaped semiconductor, and storage of signal charges by the photoelectric conversion, and the first island shape The thickness of the third semiconductor region of the semiconductor is thinner 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 higher than that of the third island-shaped semiconductor 3 The thickness of the semiconductor region is thin, and the first island-shaped semiconductor, the second island-shaped semiconductor, and the third island-shaped semiconductor are adjacent to each other Formation.

Preferably, a color filter of a primary color type or a complementary color type is provided on either the first island-shaped semiconductor or the second island-shaped semiconductor, and is included in light that has passed through the color filter. a light wavelength component in which light absorption and signal charge storage are performed in the first island-shaped semiconductor located below the color filter or in the diode region in the second island-shaped semiconductor .

Preferably, in the pixel region, the upper portion is formed such that a blue wave is formed The first island-shaped semiconductor of the color filter through which the long light passes, and the first island-shaped semiconductor in which the color filter for transmitting the blue wavelength light is not formed on the upper portion, and the blue wavelength is not formed from the upper portion The first island-shaped semiconductor of the light-transmitting color filter is obtained by a white signal current including a blue wavelength light component, a green wavelength light component, and a red wavelength light component.

Preferably, the third semiconductor region transmits blue wavelength light, green wavelength light, and red wavelength light incident from the upper end surface of the island-shaped semiconductor, and the third semiconductor region is incident from the upper end surface of the island-shaped semiconductor. The blue wavelength light, the plurality of island-shaped semiconductors include: a fourth island-shaped semiconductor having a diode region, wherein the diode region transmits blue wavelength light, green wavelength light, and red wavelength that have passed through the third semiconductor region Photoelectric conversion of light and storage of signal charges by the photoelectric conversion; and a fifth island-shaped semiconductor having a diode region, wherein the diode region transmits green wavelength light and red wavelength light that has passed through the third semiconductor region The photoelectric conversion of one or both of the photoelectric conversion and the storage of the photoelectrically converted signal charge, the thickness of the third semiconductor region of the fifth island-shaped semiconductor being equal to or thicker than the above-described fourth island-shaped semiconductor The thickness of the third semiconductor region is such that a sixth island-shaped semiconductor is formed in the pixel region, and the sixth island-shaped semiconductor has the fourth island-shaped half a conductor having the same structure as the second semiconductor region and the third semiconductor region in the fifth island-shaped semiconductor, wherein a primary color or a complementary 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.

Preferably, the third semiconductor region transmits blue wavelength light, green wavelength light, and red wavelength light incident from the upper end surface of the island-shaped semiconductor, and the third semiconductor region is incident from the upper end surface of the island-shaped semiconductor. The blue wavelength light, the plurality of island-shaped semiconductors include: a seventh island-shaped semiconductor having a diode region, wherein the diode region transmits blue wavelength light, green wavelength light, and red wavelength that have passed through the third semiconductor region Photoelectric conversion of light and storage of signal charges obtained by the photoelectric conversion; and an eighth island-shaped semiconductor having a diode region, wherein the diode region transmits green wavelength light that has passed through the third semiconductor region and The photoelectric conversion of the red wavelength light and the storage of the signal charge by the photoelectric conversion, the thickness of the third semiconductor region of the eighth island-shaped semiconductor is formed thicker than the thickness of the third semiconductor region of the seventh island-shaped semiconductor Forming a ninth island-shaped semiconductor in the pixel region, the ninth island-shaped semiconductor having the seventh island-shaped semiconductor and the first In the same structure as the second semiconductor region and the third semiconductor region in the island-shaped semiconductor, a primary color or complementary color filter is formed on the ninth island-shaped semiconductor, and the seventh island-shaped semiconductor and the The eighth island semiconductor, the ninth island shape The semiconductor is formed in an abutting manner.

Preferably, an insulating layer that transmits light is formed between the substrate and the first semiconductor region, and a thickness of the insulating layer is set as follows: a light incident from a surface of an upper end portion of the island-shaped semiconductor is returned from the insulating layer The light to the above-described diode region of the island-shaped semiconductor has a red wavelength component larger than that of the green wavelength component.

Preferably, in the pixel region, at least two of the island-shaped semiconductors having different thicknesses in the third semiconductor region are arranged in a zigzag shape or a checkerboard shape.

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

1, 100, 111, 111a‧‧‧ substrates

1a‧‧‧Semiconductor substrate

2a, 2b, 2c, 112, 112a, 112b, 112c‧‧‧ signal line N ⁺ area

3a, 3b, 3c, 113, 113a, 113b, 113c‧‧‧P area

4a, 4b, 4c, 114, 114a, 114b, 114c‧‧‧ insulation

5, 5a, 5b, 5c, 115, 115a, 115b, 115c‧‧‧ conductor layer

6a, 6b, 6c, 6bb, 6cc, 16a, 16b, 16c, 116, 116a, 116b, 116c‧‧‧N areas

7a, 7b, 7c, 7bb, 7cc, 20a, 20b, 20c, 117, 117a, 117b, 117c‧ ‧ P ⁺ area

8, 8a, 8b, 8c, 118, 118a, 118b, 118c‧‧‧ pixel selection line conductor layer

9a‧‧‧1st interlayer insulation

9b‧‧‧2nd interlayer insulation

9c, 9e, 120d‧‧‧ protective layer insulation

9d‧‧‧Interlayer insulation

10a, 10b, 10c, 10bb, 10cc, 119‧‧‧photodiode regions

11, 106B, B1, B2, B3‧‧‧ blue (B) with color filters

12, 12a, 12b, 12c, 106G, G1, G2, G3‧‧‧ Green (G) color filters

13, 106R, R1, R2, R3‧‧‧ red (R) color filter

14a‧‧‧ incident light

14b, 14c‧‧‧ reflected light

17, 18, 20, 120a, 120b, 120c‧‧‧ insulation

19‧‧‧ photoresist layer

101a~101d‧‧‧Separation of yttrium oxide layer

102a~102c‧‧‧N area

103‧‧‧Interlayer SiO ₂ layer

104a~104d‧‧‧Metal wiring

105‧‧‧Protective insulation

107a~107c‧‧‧Separation insulation

121‧‧‧P area substrate

122‧‧‧N area (N well)

123‧‧‧P area (P well)

124‧‧‧N area

125a, 125b, 125c‧‧‧ galvanometer

126a, 126b, 126c‧‧‧ diode regions

127a, 127b, 127c‧‧‧ contact holes

128a, 128b, 128c‧‧‧ lead lines

129a, 129b, 129c‧‧‧ output circuits

130a‧‧‧Blue (B) signal line

130b‧‧‧Green (G) signal line

130c‧‧‧Red (R) signal line

Am‧‧‧Amplifier MOS transistor

H1, H2, H3, H11~H33, H2A, H3A, 110, P11~P33‧‧‧ island semiconductor

Thickness (depth) of L7a‧‧‧P ⁺ zone 7a

Thickness (depth) of L7b‧‧‧P ⁺ zone 7b

Thickness (depth) of L7c‧‧‧P ⁺ zone 7c

LG‧‧‧ height of conductor layer 5

RS‧‧‧ select MOS transistor

Re‧‧‧Reset MOS transistor

VB‧‧‧Blue (B) signal output

VG‧‧‧Green (G) signal output

VR‧‧‧Red (R) signal output

Fig. 1A is a cross-sectional structural view of a solid-state imaging device according to a first embodiment of the present invention.

Fig. 1B is a plan view showing the solid-state imaging device of the first embodiment.

2A is a cross-sectional structural view for explaining a method of manufacturing the solid-state imaging device according to the first embodiment.

2B is a cross-sectional structural view for explaining a method of manufacturing the solid-state imaging device according to the first embodiment.

2C is a cross-sectional structural view illustrating a method of manufacturing the solid-state imaging device according to the first embodiment.

2D is a cross-sectional structural view illustrating a method of manufacturing the solid-state imaging device according to the first embodiment.

3A is a cross-sectional structural view of a solid-state imaging device in which a color filter for green (G) according to a second embodiment of the present invention is provided.

Fig. 3B is a plan view showing a solid-state imaging device in which a color filter for green (G) according to the second embodiment is provided.

3C is a cross-sectional structural view of a solid-state imaging device in which a color filter for blue (B) according to the second embodiment is provided.

4A is a cross-sectional structural view of a solid-state imaging device in which a color filter for green (G) according to a third embodiment of the present invention is provided.

4B is a cross-sectional structural view of a solid-state imaging device in which a red (R) color filter of a third embodiment is provided.

Fig. 5 is a cross-sectional structural view showing a solid-state imaging device according to a fourth embodiment of the present invention.

Fig. 6 is a cross-sectional structural view showing a conventional example of a solid-state imaging device in which color filters for red (R), green (G), and blue (B) are formed.

7A is a cross-sectional structural view of a solid-state imaging device of a conventional example in which one island semiconductor is formed into one pixel.

Fig. 7B is a plan view of a solid-state imaging device of a conventional example including an island-shaped semiconductor arranged in two dimensions.

Fig. 7C is a cross-sectional structural view showing a solid-state imaging device of a conventional example in which color filters for red (R), green (G), and blue (B) are formed.

Figure 8A is a color filter that does not form red (R), green (G), and blue (B) A cross-sectional structural view of a conventional solid-state imaging device capable of color photography using a light sheet.

Fig. 8B shows the internal light absorption characteristics of the red (R), green (G), and blue (B) wavelength light in the 矽 (Si) from the Si surface.

Fig. 8C shows the spectral sensitivity characteristics of the red (R), green (G), and blue (B) signal outputs of the solid-state imaging device of Fig. 8A.

Figure 8D is a plan view of the solid-state imaging device of Figure 8A.

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

(First embodiment)

Hereinafter, a solid-state imaging device according to a first embodiment of the present invention will be described with reference to FIGS. 1A and 1B.

Fig. 1A shows a cross-sectional structure of a solid-state imaging device according to the present embodiment.

As shown in FIG. 1A, a signal line N ⁺ region 2a, a signal line N ⁺ region 2b, and a signal line N ⁺ region 2c are formed on the substrate 1. An island-shaped semiconductor H1, an island-shaped semiconductor H2, and an island-shaped semiconductor H3 are formed on the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c. The island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are formed to form an island-shaped semiconductor so as to be connected to the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c. The parent semiconductor region of the H1, the island-shaped semiconductor H2, and the mother semiconductor H3, that is, the P region 3a, the P region 3b, and the P region 3c. An insulating layer 4a, an insulating layer 4b, and an insulating layer 4c are formed on the outer peripheral portions of the P region 3a, the P region 3b, and the P region 3c, and the conductor layer 5 is formed on the island via the insulating layer 4a, the insulating layer 4b, and the insulating layer 4c. The outer peripheral portion of the semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3.

The conductor layer 5 is formed such that the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are connected to each other. In the outer peripheral surface of the island-shaped semiconductor H1, the island-shaped semiconductor H2, the island-shaped semiconductor H3, and the P region 3a, the P region 3b, and the P region 3c located above the upper end of the conductor layer 5, an N region is formed. 6a, N region 6b, N region 6c. The surface layer of the upper end portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 so as to be in contact with the N region 6a, the N region 6b, the N region 6c, the P region 3a, the P region 3b, and the P region 3c. The P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c are formed.

In the present embodiment, the height (thickness) of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 of the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c are different from each other (in FIG. 1A, P ⁺ The thickness of the region 7a (here, the depth from the surface of the upper portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 from which incident light is incident. Hereinafter, the P ⁺ region 7b, the P ⁺ region 7c, and the like are also Similarly, for L7a, the thickness of the P ⁺ 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). The P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c are all connected to the pixel selection line conductor layer 8. The first interlayer insulating layer 9a is formed on the substrate 1 so as to surround the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3. The conductor layer 5 is formed on the first interlayer insulating layer 9a, and the second interlayer insulating layer 9b is formed on the conductor layer 5 and the first interlayer insulating layer 9a. A protective layer insulating layer 9c is formed on the second interlayer insulating layer 9b and the pixel selection line conductor layer 8.

In the solid-state imaging device of the present embodiment, the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are formed by the P region 3a, the P region 3b, the P region 3c, the N region 6a, the N region 6b, and the N region 6c. Photodiode region 10a, photodiode region 10b, and photodiode region 10c. Here, when light is incident from the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c side of the surface layer of the upper end portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, the photodiode region is present. The photoelectric conversion region of 10a, the photodiode region 10b, and the photodiode region 10c generates signal charges (here, free electrons). Further, the generated signal charges are mainly stored in the photodiode region 10a, the photodiode region 10b, and the N region 6a, the N region 6b, and the N region 6c of the photodiode region 10c.

Further, in the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, a junction field effect transistor is formed, and the junction field effect transistor has the N region 6a, the N region 6b, and the N region 6c as gate electrodes. P ⁺ region 7a, P ⁺ region 7b, P ⁺ region 7c as source, signal line N ⁺ region 2a, signal line N ⁺ region 2b, P region 3a near signal line N ⁺ region 2c, P region 3b, P Area 3c is used as a bungee. Further, in the solid-state imaging device, the drain-source current (output signal) of the junction field effect transistor changes according to the amount of signal charge stored in the N region 6a, the N region 6b, and the N region 6c, and serves as The signal is outputted from the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c.

Further, in the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, a MOS transistor is formed, which has a photodiode region 10a, a photodiode region 10b, and a photodiode region. The N region 6a, the N region 6b, and the N region 6c of 10c serve as the source, the conductor layer 5 serves as the gate, the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c serve as the drain , the N region 6a, the N region 6b, the N region 6c and the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal region N ⁺ region 2c between the P region 3a, the P region 3b, and the P region 3c serve as channels .

In the solid-state imaging device, a signal voltage stored in the N region 6a, the N region 6b, and the N region 6c is applied by applying a turn-on voltage (a high level voltage) to the conductor layer 5 which is a gate of the MOS transistor. The signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c are removed.

When the cross section of the solid-state imaging device of the present embodiment is compared with the solid-state imaging device of the conventional example shown in FIG. 7C, the following two aspects are different.

In other words, in the solid-state imaging device of the present embodiment, the RGB color filters (color filter B1, color filter G1, and color filter) formed in the solid-state imaging device of the prior art are not formed. Light sheet R1). On the other hand, in the solid-state imaging device of the prior art, the thicknesses of the P ⁺ region 117a, the P ⁺ region 117b, and the P ⁺ region 117c are equal to each other, whereas the P ⁺ region 7a, P ⁺ in the solid-state imaging device of the present embodiment ^. The thickness of the region 7b and the P ⁺ region 7c are different from each other.

When the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are formed of ytterbium (Si), it is preferable to have the following dimensions and structures according to 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 semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 is preferably about 2 μm, and the height LG of the conductor layer 5 surrounding the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 is preferably 0.2 μm or less. The thickness of the constituent elements differs depending on the characteristics of the infrared cutoff filter provided on the surface of the solid-state imaging device or the desired color reproduction characteristics in order to obtain a predetermined spectral sensitivity characteristic.

There are a plurality of holes in the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c. Therefore, the light absorbed in the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c among the incident light incident from the surface of the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c is generated. The signal charge (in this case, free electrons) is recoupled from the plurality of holes in the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c, and disappears. Therefore, the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c are ineffective regions with respect to light sensitivity. On the other hand, in the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, the photodiode is formed by the N region 6a, the N region 6b, the N region 6c, the P region 3a, the P region 3b, and the P region 3c. The region 10a, the photodiode region 10b, and the photodiode region 10c, the photodiode region 10a, the photodiode region 10b, and the photodiode region 10c become photoelectric conversion regions. Further, the signal charges generated in the photoelectric conversion region are mainly stored in the N region 6a, the N region 6b, and the N region 6c.

Referring to Fig. 1, in the island-shaped semiconductor H1, since the thickness L7a of the P ⁺ region 7a is 0.1 μm or less, in the photodiode region 10a composed of the N region 6a and the P region 3a, mainly from the P ⁺ region The blue (B), green (G), and red (R) wavelengths incident on the surface of 7a generate signal charges, which are mainly stored in the N region 6a.

The island-shaped semiconductor H2, because the thickness of the P ⁺ region 7b L7b is approximately of 0.4 m, so that from the surface of the P ⁺ region 7b of the incident light, the blue (B) wavelength light is absorbed P ⁺ region 7b. Therefore, in the photodiode region 10b including the N region 6b and the P region 3b, signal charges are mainly generated by green (G) wavelength light and red (R) wavelength light, and the generated signal charges are mainly stored in the N region 6b. .

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. Therefore, in the photodiode region 10c including the N region 6c and the P region 3c, signal charges are mainly generated by red (R) wavelength light incident from the surface of the P ⁺ region 7c, and the generated signal charges are mainly stored in N. In area 6c. By applying a high level voltage to the conductor layer 5, the signal charges stored in the N region 6a, the N region 6b, and the N region 6c are used as signal currents from the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N. ⁺ Read in area 2c.

The signal charge read from the signal line N ⁺ region 2b is mainly generated by the incident green (G) wavelength light and the red (R) wavelength light, and the signal charge read from the signal line N ⁺ region 2c is mainly incident. Produced by red (R) wavelength light. Therefore, the processing of subtracting the signal current from the signal line N ⁺ region 2c from the signal current derived from the signal line N ⁺ region 2b is performed by the external arithmetic circuit, thereby obtaining a green (G) signal. Further, the signal current read from the signal line N ⁺ region 2a is a signal mainly generated by incident red (R) wavelength light, green (G) wavelength light, and blue (B) wavelength light. Therefore, the following signals are subtracted by an external circuit to obtain a blue (B) signal, which is a green (G) signal and a red (R) signal obtained by the above-described arithmetic processing, and a self-signal line. The signal generated by the N ⁺ region 2a is mainly generated by blue (B) wavelength light, green (G) wavelength light, and red (R) wavelength light. 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. As described above, in the solid-state imaging device of the present embodiment, color photography can be performed even if the RGB color filter is not provided.

1B shows an island-shaped semiconductor H1 and an island-shaped semiconductor including the one shown in FIG. 1A. H2. Planar view of the solid-state imaging device of the present embodiment in which the pixels of the island-shaped semiconductor H3 are arranged in two dimensions (matrix). A cross-sectional view along the one-dot line A-A' in Fig. 1B corresponds to Fig. 1A.

As shown in FIG. 1B, the island-shaped semiconductor H11 to the island-shaped semiconductor H33 are arranged in two dimensions (H11 corresponds to H1 of FIG. 1A, H12 corresponds to H2, and H13 corresponds to H3). The signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c are formed in a strip shape in the longitudinal direction. An island-shaped semiconductor H11, an island-shaped semiconductor H21, and an island-shaped semiconductor H31 in which a blue (B) pixel is disposed is disposed on the signal line N ⁺ region 2a. An island-shaped semiconductor H12, an island-shaped semiconductor H22, and an island-shaped semiconductor H32 having green (G) pixels are disposed on the signal line N ⁺ region 2b. An island-shaped semiconductor H13, an island-shaped semiconductor H23, and an island-shaped semiconductor H33 in which a red (R) pixel is disposed is disposed on the signal line N ⁺ region 2c.

Conductor layer 5a (corresponding to conductor layer 5 of Fig. 1A), conductor layer 5b, conductor The bulk layer 5c surrounds the island-shaped semiconductor H11 to the island-shaped semiconductor H13, the island-shaped semiconductor H21, the island-shaped semiconductor H23, and the island-shaped semiconductor H31-island which are arranged in the horizontal direction, respectively. The outer peripheral portion of the semiconductor H33 is formed such that the island-shaped semiconductor H11 to the island-shaped semiconductor H13, the island-shaped semiconductor H21 to the island-shaped semiconductor H23, and the island-shaped semiconductor H31 to the island-shaped semiconductor H33 are connected to each other.

Moreover, the pixel selection line conductor layer 8a (with the pixel selection line guide in FIG. 1A) The bulk layer 8 corresponds to the pixel selection line conductor layer 8b and the pixel selection line conductor layer 8c to surround the island-shaped semiconductor H11 to the island-shaped semiconductor H13, the island-shaped semiconductor H21 to the island-shaped semiconductor H23, and the islands arranged in the horizontal direction. The outer peripheral portion of the semiconductor H31 to the island-shaped semiconductor H33, and the island-shaped semiconductor H11 to the island-shaped semiconductor H13, the island-shaped semiconductor H21 to the island-shaped semiconductor H23, and the island-shaped semiconductor H31 to the island-shaped semiconductor H33 are connected to each other. form.

In the solid-state imaging device of the present embodiment, the pixel H11 to the pixel H33 The signal reading is performed by the same operation as the solid-state imaging device of the conventional example shown in Fig. 7B. Thereby, the solid-state imaging device can perform color photography even if the RGB color filter is not provided on the island-shaped semiconductor H11 to the island-shaped semiconductor H33.

In the solid-state imaging device of the embodiment shown in FIG. 1B, it is not necessary to The RGB color filter B1, the RGB color filter B2, the RGB color filter B3, the RGB color filter R1, the RGB color filter R2, and the RGB necessary for the solid-state imaging device of the prior art shown in FIG. 7B. Color filter R3, RGB color filter G1, RGB color filter G2, RGB color filter G3. In the solid-state imaging device of the prior art shown in FIG. 7B, RGB color filter B1, RGB color filter B2, RGB color filter B3, RGB color filter R1, RGB color filter R2, RGB color Filter R3, RGB color filter G1, RGB color filter The G2 and RGB color filters G3 are formed so as to surround the island-shaped semiconductor P11 to the island-shaped semiconductor P33. Therefore, in order to secure the mask alignment tolerance of the manufacturing, it is necessary to be in the island-shaped semiconductor P11 to the island-shaped semiconductor P33. Set space between.

On the other hand, in the solid-state imaging device of the present embodiment, since it is not necessary to secure the mask alignment tolerance in the above manufacturing, the space between the island-shaped semiconductors P11 and the island-shaped semiconductors P33 can be reduced accordingly. Thereby, high-density density achieved by increasing the density of the island-shaped semiconductors H11 to H1 to the island-shaped semiconductors H33 or high sensitivity by the increase in the diameter of the island-shaped semiconductors H11 to H33 themselves can be achieved. .

Further, the solid-state imaging device according to the present embodiment is different from the solid-state imaging device of the prior art shown in Figs. 6, 7C, and 8A in that all blue (B), green (G), and red (R) can be included. The white (W) wavelength signal of the wavelength light is taken out from the island-shaped semiconductor H1 which is a blue (B) pixel. In the solid-state imaging device of the prior art shown in FIG. 6 and FIG. 7C, since RGB color filters are provided on each pixel, it is not possible to directly obtain all blue (B), green (G), and red (R). A white (W) wavelength signal of wavelength light. Further, in the solid-state imaging device of the prior art shown in Fig. 8A, the diode region 126a, the diode region 126b, and the diode region 126c independently obtain blue (B), green (G), and red (R), respectively. A signal of wavelength light, but a white (W) wavelength signal cannot be obtained. On the other hand, in the solid-state imaging device of the present embodiment, the island-shaped semiconductor H1 is a blue (B) pixel, and functions as a white (W) pixel. Thereby, a solid-state imaging device that achieves high sensitivity and high dynamic range is obtained. Further, in the solid-state imaging device of the present embodiment, since the RGB color filter is not required, the cost can be reduced.

In the first embodiment shown in FIG. 1A, each RGB color signal is a signal line N ⁺ region 2a and a signal line N from the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 arranged in the horizontal direction. The signal current of the ⁺ region 2b and the signal line N ⁺ region 2c is obtained by arithmetic processing. The P ⁺ region of the upper end surface layer of the island-shaped semiconductor H11 to the island-shaped semiconductor H33 arranged in the longitudinal direction shown in FIG. 1B (the P ⁺ region 7a and the P ⁺ region 7b of FIG. 1A) may be changed. The configuration of the RGB pixel is changed by the arrangement of the P ⁺ region 7c.

The color signal is obtained by arithmetic processing of the signal currents from the island-shaped semiconductors H11 to H1 to the island-shaped semiconductors H33 which are arranged in the vertical direction and which constitute the color pixels for the respective colors (red, green, and blue). In this case, the island-shaped semiconductors H11 to H33 arranged in the vertical direction are not the same color chromin, and thus a color photographic solid such as a Bayer type arrangement is arranged in a checkerboard color solid state for color photography. Photography device. In the solid-state imaging device of the present embodiment, the P ⁺ region of the upper end portion of the island-shaped semiconductor H11 to the island-shaped semiconductor H33 is changed (the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c of FIG. 1A). Corresponding to the configuration, a solid-state imaging device in which a coloring pixel is arranged in a stripe or checkerboard pattern is realized.

In addition, in FIG. 1A, the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c have a function as a drain of the junction field effect transistor, and are stored as a removal in the N region 6a. The function of the drain of the signal charge of the N region 6b and the N region 6c. The present invention is not limited to this, and the technical idea of the present invention is also applicable to a configuration in which the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c are regions (for example, refer to Patent Document 4), which includes It is a P ⁺ region of the signal line, a P region connected to the P ⁺ region, and an N ⁺ region for removing signal charges. That is, the signal line N ⁺ region may also include a plurality of semiconductor regions having a prescribed 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 also applicable to the outer peripheral portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, the island-shaped semiconductor H3, and the N region 6a, the N region 6b, the N region 6c, the insulating layer 4a, the insulating layer 4b, and the insulating layer. The structure of the P ⁺ region is provided between the layers 4c (for example, refer to Patent Document 5 and Patent Document 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 charges stored in the N region 6a, the N region 6b, and the N region 6c are applied with a turn-on voltage (a high level voltage) by the conductor layer 5 which is a gate of the MOS transistor. The signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c are removed. However, such signal charge removal may not apply a turn-on voltage (high level voltage) to the conductor layer 5, but a high level is applied to the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c. The voltage is applied. Such a configuration can also be applied to other embodiments of the present invention described below.

Based on the above, the following matters are listed as basic items for obtaining the effects achieved by the technical idea of the present invention.

In other words, the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c are formed in the surface layer of the upper end portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, and the P ⁺ region 7a, P ⁺ region 7b, P ⁺ region 7c is the source of the junction field effect transistor, and contains a receptor impurity of a sufficiently high concentration for the signal charge (free electron) generated here to re-couple with the hole and disappear, and The lower portion of the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c forms a photodiode region 10a, an optical diode region 10b, and an optical diode region 10c for performing photoelectric conversion and signal charge storage. Further, in the P ⁺ region 7a, the P ⁺ region 7b, the island semiconductor H1 of the P ⁺ region 7c, the island-shaped semiconductor H2, the thickness L7a in the island-shaped semiconductor H3, the thickness L7b, and the thickness L7c, the thickness of the P ⁺ region 7a L7a is thinner than the thickness L7b of the P ⁺ region 7b, and 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 solid state photography of the first embodiment shown in Fig. 1A An example of a method of manufacturing the device.

First, as shown in FIG. 2A, a signal line N ⁺ region 2a, a signal line N ⁺ region 2b, and a signal line N ⁺ region 2c are formed on the substrate 1, and the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, An island-shaped semiconductor H1, an island-shaped semiconductor H2, and an island-shaped semiconductor H3 are formed on the signal line N ⁺ region 2c.

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

Then, the conductor layer 5 is formed on the outer peripheral portion of the insulating layer 9a, the island-shaped semiconductor H1, the island-shaped semiconductor H2, the insulating layer 4a of the island-shaped semiconductor H3, the insulating layer 4b, and the insulating layer 4c, and an island shape on the upper portion of the conductor layer 5 The semiconductor H1, the island-shaped semiconductor H2, the P region 3a of the island-shaped semiconductor H3, the P region 3b, and the outer peripheral portion of the P region 3c, for example, the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are germanium (Si). In this case, the N region 16a, the N region 16b, and the N region 16c are formed by arsenic (As) ion implantation.

Then, an insulating layer 17 is formed on the conductor layer 5 between the insulating layer 9a and the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, and the insulating layer 17 is made of, for example, chemical mechanical polishing (CMP). The heights of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are equal to each other, and the surfaces of the insulating layer 17 and the island-shaped semiconductors H1, H2, H3 are planarized, and thin insulation is formed on the insulating layer 17. Layer 18. Further, on the island-shaped semiconductor H3 on the insulating layer 18, a photoresist layer 19 having an opening is formed.

Then, as shown in FIG. 2B, ion implantation of, for example, boron (B) ions as acceptor impurities is performed through the opening of the photoresist layer 19, thereby forming a P ⁺ region having a depth L7c at the upper end portion of the island-shaped semiconductor H3. 20c. In this case, since the island-shaped semiconductor H1 and the island-shaped semiconductor H2 are covered by the photoresist layer 19, boron (B) ions are not implanted into the island-shaped semiconductor H1 and the island-shaped semiconductor H2. Then, the photoresist layer 19 is removed.

Then, as shown in FIG. 2C, in the upper surface portion of the island-shaped semiconductor H2, the P ⁺ region 20b of the depth L7b is formed by the same method as the formation of the P ⁺ region 20c of the island-shaped semiconductor H3, and the photoresist layer is formed. Remove.

Then, boron (B) ion implantation is performed on the entire surface layer of the insulating layer 18, and a P ⁺ region 20a having a depth L7a is formed on the surface of the upper end 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 portion of the island-shaped semiconductor H2 and the island-shaped semiconductor H3 to the position indicated by the broken line in FIG. 2C. However, in the P ⁺ region 20b and the P ⁺ region 20c, a large amount of boron (B) ions have been implanted into a position deeper than the P ⁺ region 20a, so that the P ⁺ region 20b and the P ⁺ region 20c are not electrically connected. Nature affects.

Then, for example, the heat treatment is performed at about 1000 ° C, whereby the donor impurities of the ion-implanted arsenic (As) in the N region 16a, the N region 16b, and the N region 16c, and the P ⁺ region 20a and the P ⁺ region 20b, P are obtained. ⁺ region 20c has been ion-implanted boron (B) impurity receptor activation, and the insulating layer 18 is removed.

Then, as shown in FIG. 2D, the insulating layer 17 and the insulating layer 4a, the insulating layer 4b, and the insulating layer 4c of the outer peripheral portion of the upper surface portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are removed. The pixel selection line conductor layer 8 is formed in such a manner that the P ⁺ region 20a, the P ⁺ region 20b, and the P ⁺ region 20c are connected.

Then, a protective layer insulating layer 9c is formed on the P ⁺ region 20a, the P ⁺ region 20b, the P ⁺ region 20c, and the pixel selection line conductor layer 8. Thereby, the solid-state imaging device of the first embodiment shown in FIG. 1A is manufactured.

(Second embodiment)

Hereinafter, a solid-state imaging device according to a second embodiment of the present invention will be described with reference to FIGS. 3A to 3C.

Fig. 3A is a cross-sectional structural view showing the solid-state imaging device of the embodiment.

Referring to Fig. 3A, a pixel structure is formed on the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 in the same manner as the solid-state imaging device of the first embodiment shown in Fig. 1A. An insulating layer 9d is formed on the interlayer insulating layer 9b and the pixel selection line conductor layer 8. The upper surface of the insulating layer 9d is flattened. On the island semiconductor H2 A green (G) color filter 12 is formed on the insulating layer 9d. A protective layer insulating layer 9e is formed on the insulating layer 9d and the green (G) color filter 12.

In the present 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 Red (R) uses pixels.

As shown in FIG. 3A, a green (G) color filter 12 is formed on the island-shaped semiconductor H2 which is a green (G) pixel, so that it is not necessary to have a signal from the island-shaped semiconductor H3 shown in FIG. 1A. The signal of the line N ⁺ region 2c is subjected to arithmetic processing, and the green (G) signal is directly obtained from the signal line N ⁺ region 2b. Similarly to FIG. 1A, the red (R) signal is obtained directly from the island-shaped semiconductor H3 which is a red (R) pixel. Further, a blue (B) signal is obtained by arithmetic processing from the signal of the island-shaped semiconductor H1 used as the blue (B) pixel and the obtained green (G) signal and red (R) signal. Moreover, by this, an RGB color signal is obtained.

In color photography, the green (G) signal is the main signal component of the luminance signal representing the outline of the image, and is also an important signal component in color reproduction, so obtaining a more accurate green (G) signal means obtaining a faithful brightness. Signal and color signals. In the solid-state imaging device of the present embodiment, the color filter 12 for green (G) is necessary, and even if three RGB color filters are not used as in the conventional solid-state imaging device, it is possible to realize the image from the object to be written. A solid-state photographic device for color photography that obtains a faithful green (G) signal in the light.

Fig. 3B is a plan view showing the solid-state imaging device in which the pixels shown in Fig. 3A are arranged in two dimensions (matrix). Figure 3A and along the one-dot line B-B' in Figure 3B The profile corresponds.

Green (G) color filter 12a, green (G) color filter 12b, green (G) color filter 12c (green (G) color filter 12a and green (G) of Fig. 3A The island-shaped semiconductor H12, the island-shaped semiconductor H22, and the island-shaped semiconductor H32 are formed so as to cover the island-shaped semiconductor H12, the island-shaped semiconductor H22, and the island-shaped semiconductor H32 by the color filter 12.

The solid-state imaging device of the present embodiment is other than the color filter for green (G) The green color (G) color filter 12b and the green (G) color filter 12c are formed in the same manner as the solid-state imaging device shown in Fig. 1B. In this case, the color filter 12a for green (G), the color filter 12b for green (G), the color filter 12c for green (G), the island-shaped semiconductor H12, the island-shaped semiconductor H22, and the island shape. Between the semiconductors H32, it is necessary to ensure the mask alignment tolerance space in the manufacturing, but unlike the solid-state imaging device of the prior art, the blue (B) color filter and the red (R) color filter are not required. Therefore, unlike the solid-state imaging device of the conventional example, high-density density and cost reduction are achieved.

In the solid-state imaging device of the present embodiment, the green (G) letter is directly obtained. Therefore, the red (R) signal obtained directly from the island-shaped semiconductor H13, the island-shaped semiconductor H23, and the island-shaped semiconductor H33 is white (W) obtained from the island-shaped semiconductor H11, the island-shaped semiconductor H21, and the island-shaped semiconductor H31. In the arithmetic processing of the signal, a more faithful blue (B) signal can be obtained from the light from the object to be written than the solid-state imaging device of the first embodiment. Thereby, more excellent color reproduction characteristics can be obtained comprehensively than the solid-state imaging device of the first embodiment. Moreover, the island semiconductor H11, The island-shaped semiconductor H21 and the island-shaped semiconductor H31 are blue (B) pixels, and function as a white (W) pixel, thereby realizing a solid-state imaging device having high sensitivity and high dynamic range.

3C is a cross-sectional structural view showing a state in which the color filter 11 for blue (B) is formed on the island-shaped semiconductor H1 in the solid-state imaging device of the embodiment. The pixel structure of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 is formed by the same manufacturing method as the solid-state imaging device of the first embodiment shown in FIG. 1A. An insulating layer 9d is formed on the interlayer insulating layer 9b and the pixel selection line conductor layer 8. The upper surface of the insulating layer 9d is flattened. A blue (B) color filter 11 is formed on the island-shaped semiconductor H1 and the insulating layer 9d. Further, a protective layer insulating layer 9e is formed on the insulating layer 9d and the blue (B) color filter 11.

In the solid-state imaging device of the present embodiment, a blue (B) signal is directly obtained from the island-shaped semiconductor H1. In general, the light obtained by the object is compared with the green (G) wavelength light and the red (R) wavelength light before reaching the photodiode region 10a which is the photoelectric conversion region of the island-shaped semiconductor H1. The surface of each lens, the reflection of the surface of the island-shaped semiconductor H1, and the light absorption in the P ⁺ region 7a, the blue (B) wavelength light is lost more. Therefore, in the photographing of a writing body containing a large amount of blue (B) wavelength light components or the photographing of a dark scene, better reproducibility of the blue (B) signal is required. On the other hand, in the solid-state imaging device of the present embodiment, the blue (B) color filter 11 is necessary, and it is not necessary to use three RGB color filters as in the conventional solid-state imaging device. A more faithful blue (B) signal is obtained in the light.

In the solid-state imaging device of this embodiment shown in FIG. 3C, it is not possible to directly A white (W) signal is obtained in the individual island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3. In this case, the island-shaped semiconductor H1 in which the color filter 11 for blue (B) is provided is formed in the same manner as the island-shaped semiconductor H1 in which the color filter 11 for blue (B) is not provided. The island-shaped semiconductor is formed to be adjacent to the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, whereby a color (W) signal can be obtained from the island-shaped semiconductor. In this case, the number of island-shaped semiconductors formed in the pixel region is increased, and a blue (B) signal having high color reproducibility is obtained, and high sensitivity and high dynamic range can be realized in the solid-state imaging device.

Further, this embodiment is applied to form red on the island-shaped semiconductor H3. The color (R) solid-state imaging device using a color filter has a small effect. The reason for this is that in such a solid-state imaging device, the island-shaped semiconductor H itself can obtain a red (R) signal. In the present embodiment, in order to obtain a multi-color wavelength light component signal, when a predetermined color filter is provided on the island-shaped semiconductor (corresponding to the island-shaped semiconductor H1 and the island-shaped semiconductor H2 in FIG. 1A), Get results.

Further, in the present embodiment, color filtering for green (G) has been used. The case of the primary color filter of the color filter 11 of the sheet 12 or the blue (B) has been described. Not limited to this, for example, even when a complementary color filter such as cyan or magenta (Mg) is used, the same effect can be obtained. 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 is The blue (B) signal output is obtained by the arithmetic processing of the red (R) signal output obtained from the island-shaped semiconductor H3. Moreover, by obtaining the red (R) The signal output is calculated by the blue (B) signal output and the signal output from the island-shaped semiconductor H1 to obtain a green (G) signal output.

(Third embodiment)

Hereinafter, the solid-state imaging device according to the third embodiment will be described with reference to FIGS. 4A and 4B. In the present embodiment, the solid-state imaging device according to the second embodiment is further improved.

Fig. 4A shows a cross-sectional structure of the solid-state imaging device of the embodiment. The island-shaped semiconductor H1, the island-shaped semiconductor H2A, and the island-shaped semiconductor H3 are formed on the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c. A green (G) color filter 12 is formed on the island-shaped semiconductor H2A.

In the present embodiment, the structures of the island-shaped semiconductor H1 and the island-shaped semiconductor H3 are the same as those of the island-shaped semiconductor H1 and the island-shaped semiconductor H3 shown in FIG. 3A, and the island-shaped semiconductor H1 is used for the blue (B) signal, and the island-shaped semiconductor H3. Used for red (R) signals. Among them, the green (G) signal island-shaped semiconductor H2A has the same structure as the island-shaped semiconductor H1, but is different from the embodiment 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 green (G) color filter 12 is formed on the island-shaped semiconductor H2A, a green (G) signal can be obtained directly from the island-shaped semiconductor H2A. Therefore, similarly to the case shown in FIG. 3A, unlike the solid-state imaging device of the conventional example, the blue (B) color filter and the red (R) color filter are not required, and thus the conventional example is High-density density can be achieved compared to solid-state imaging devices. Further, compared with the solid-state imaging device of the first embodiment, more excellent color reproduction characteristics can be obtained comprehensively.

Further, 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 high dynamic range. As described above, the solid-state imaging device having the same features as those of FIG. 3A can be realized by the island-shaped semiconductor structure, which includes the P ⁺ region 7a, the P ⁺ region 7bb, and the island-shaped semiconductor H1 having the same thickness. and island-shaped semiconductor H2A than the island-shaped semiconductor having a P ⁺ region 7a, P ⁺ P ⁺ region 7bb thicker region H3. According to the above configuration, the step of forming the P ⁺ region 7b of the island-shaped semiconductor H2 of the solid-state imaging device shown in Fig. 3A is not required, and the P ⁺ region 7a, P ^{+ of the} island-shaped semiconductor H1, the island-shaped semiconductor H2A can be simultaneously formed ^. The area 7bb, thus, can be obtained at a lower cost than the solid-state imaging device of Fig. 3A.

4B is a structural cross-sectional view showing a case where a red (R) color filter 13 is formed on the island-shaped semiconductor H3A in the solid-state imaging device of the embodiment.

As shown in FIG. 4B, in the present embodiment, the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3A are formed on the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, and the signal line N ⁺ region 2c.

In the present embodiment, the structures of the island-shaped semiconductor H1 and the island-shaped semiconductor H2 are the same as those of the island-shaped semiconductor H1 and the island-shaped semiconductor H2 shown in FIG. 3A, and the island-shaped semiconductor H1 is used for the blue (B) signal, and the island-shaped semiconductor H2. Used for green (G) signals. Among them, the red (R) signal island-shaped semiconductor H3A and the island-shaped semiconductor H1 have the same structure, which is different from the embodiment shown in FIG. 3A. The thickness of the P ⁺ region 7cc and the N region 6cc is equal to the thickness 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. Thus, a color solid-state imaging device including an island-shaped semiconductor H1 having an equal thickness of P ⁺ region 7a, a P ⁺ region 7cc, an island-shaped semiconductor H3A, and an island having a thicker P ⁺ region 7b can be realized. Two structures of the semiconductor H2. Thereby, the step of forming the P ⁺ region 7c of the island-shaped semiconductor H3 of the solid-state imaging device shown in FIG. 3A is not required, and the P ⁺ region 7a and the P ⁺ region of the island-shaped semiconductor H1 and the island-shaped semiconductor H3A can be simultaneously formed. 7cc, and thus the solid-state imaging device can be obtained at a lower cost than the solid-state imaging device shown in Fig. 3A.

Further, in the present embodiment, even when applied to a solid-state imaging device in which a color filter for blue (B) is formed on the island-shaped semiconductor H1, the effect obtained is small. The reason for the above-described solid-state imaging device is that P ⁺ region 7a, P ⁺ region 7b, P having the same thickness as the solid-state imaging device shown in FIG. 1A on the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3. ⁺ Area 7c is required. In the present embodiment, an effect is obtained by applying a solid-state imaging device to an island-shaped semiconductor that obtains a signal other than the blue (B) signal (corresponding to the island-shaped semiconductor H2 and the island-shaped semiconductor H3 in FIG. 1A). ) A color filter such as green or red is set on the screen.

(Fourth embodiment)

Hereinafter, a solid-state imaging device according to a fourth embodiment of the present invention will be described with reference to Fig. 5 .

Referring to Fig. 5, an insulating layer 20 that transmits light is formed on the light-absorbing semiconductor substrate 1a. Then, in the same manner as the first embodiment shown in FIG. 1A, the island-shaped semiconductor A pixel is formed on the H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3.

In the solid-state imaging device of the present embodiment, a part of the incident light ray 14a that has entered the surface of the insulating layer 20 by entering the island-shaped semiconductor H3 for red (R) is divided into the semiconductor substrate 1a through the insulating layer 20. The light ray, the reflected ray 14b reflected by the interface between the signal line N ⁺ region 2c and the insulating layer 20, and the reflected ray 14c reflected by the interface between the semiconductor substrate 1a and the insulating layer 20. Among them, a part of the reflected light 14b and the reflected light 14c reaches the photodiode region 10c which is a photoelectric conversion region, and generates a signal charge. Here, the thickness of the insulating layer 20 is set as follows: by the multiple reflection effect of the incident light 14a in the insulating layer 20 and the light absorbing effect in the semiconductor substrate 1a, the intensity of the reflected light 14b and the reflected light 14c is in red The (R) wavelength light is larger than the green (G) wavelength light.

It is seen that the light incident on the surface of the Si (矽) substrate shown in FIG. 8B is The light absorption intensity characteristic in the depth direction of the Si substrate is absorbed in the deeper Si substrate than the green (G) wavelength light (wavelength λ = 550 nm), and the red (R) wavelength light (wavelength λ = 700 nm) . The island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are formed of yttrium (Si), and the height of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 is 2 μm by the red (R) wavelength. Determined by light absorption characteristics. Here, by increasing the intensity of the reflected light 14b and the reflected light 14c of the red (R) wavelength light, the heights of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 can be lowered without lowering the sensitivity. Thus, by lowering the heights of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3, the bottom portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 is obtained. The processing of the conductor layer 5 becomes easy to manufacture and the like. Further, in the case where the heights of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are not changed, the absorption of the red (R) wavelength light in the photodiode region 10c is increased, thereby realizing the solid-state imaging device. High sensitivity.

In the present embodiment, a transparent insulating layer is provided between the semiconductor substrate and the island-shaped semiconductor constituting the pixel, and green (G) wavelength light or red (R) wavelength realized by the multiple reflection effect in the transparent insulating layer is used. The light is fed back to the island-shaped semiconductor to reduce the height of the island-shaped semiconductor, thereby facilitating the manufacturing method or increasing the sensitivity (for example, refer to Patent Document 3). In the first embodiment to the third embodiment, since the thickness of 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 can be seen from FIG. 8B, the greater the degree of light absorption in the upper portion of the island-shaped semiconductor H3, the lower the sensitivity due to light absorption at the red (R) wavelength. On the other hand, according to the present embodiment, the above-described decrease in sensitivity is alleviated.

Further, in the above-described embodiment, the pixel arrangement can be applied to the surface layer of the upper end portion of the island-shaped semiconductor H11 to the island-shaped semiconductor H33 by changing the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region having different thicknesses. In the configuration of 7c, the primary color or complementary color color pixel arrangement is arranged in a checkerboard shape such as a stripe shape or a Bayer type configuration. On the other hand, even if the island-shaped semiconductors are arranged in a zigzag or checkerboard shape, each of the island-shaped semiconductors can function as a predetermined color signal pixel by signal processing.

In the first embodiment shown in Fig. 1A, P region 3a, P region 3b, P The region 3c is a P region, but may be a true semiconductor region in which the N region 6a, the N region 6b, the N region 6c, and the diode are formed. The above 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 the pixels formed on the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 can perform a predetermined imaging operation.

In the first embodiment shown in FIG. 1A, the N ⁺ region 2a, the N ⁺ region 2b, and the N ⁺ region 2c located in the lower portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3 are used as signal lines. The conductor layer 8 connected to the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c located at the upper portion serves as a pixel selection line, but may also be a lower portion of the island-shaped semiconductor H1, the island-shaped semiconductor H2, and the island-shaped semiconductor H3. The N ⁺ region 2a, the N ⁺ region 2b, and the N ⁺ region 2c are used as a pixel selection line, and the conductor layer 8 connected to the upper P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c is used as a signal line. In this case, in the plan view shown in FIG. 1B, the conductor layer 8a, the conductor layer 8b, and the conductor layer 8c are formed in the longitudinal direction of the drawing, and the N ⁺ region 2a, the N ⁺ region 2b, and the N ⁺ region 2c are formed in the horizontal direction. The above configuration can be similarly applied to other embodiments of the present invention.

Further, in FIG. 1A, the signal line N ⁺ region 2a, the signal line N ⁺ region 2b, the signal line N ⁺ region 2c, the island-shaped semiconductor P region 3a, the island-shaped semiconductor P region 3b, the island-shaped semiconductor P region 3c, The case of the diode N region 6a, the diode N region 6b, the diode N region 6c, the P ⁺ region 7a, the P ⁺ region 7b, and the P ⁺ region 7c has been described. The present invention is not limited thereto, and may be a signal line P ⁺ region 2a, a signal line P ⁺ region 2b, a signal line P ⁺ region 2c, a diode P region 6a, a diode P region 6b, a diode P region 6c, N. ^{The configuration of the +} 7a, N ⁺ 7b, and N ⁺ 7c. The above configuration can be similarly applied to other embodiments of the present invention.

The pixel selection line conductor layer 8 may be 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 to cover the surface of the P ⁺ region.

Further, various embodiments and modifications may be made without departing from the spirit and scope of the invention. Further, the above embodiments are intended to describe an embodiment of the present invention, and do not limit the scope of the present invention.

(industrial availability)

The present invention can be widely applied to a solid-state imaging device for color photography using an island-shaped semiconductor to form a pixel.

1‧‧‧Substrate

2a, 2b, 2c‧‧‧ signal line N ⁺ area

H1, H2, H3‧‧‧ island semiconductor

3a, 3b, 3c‧‧‧P area

4a, 4b, 4c‧‧‧ insulation

5‧‧‧Conductor layer

6a, 6b, 6c‧‧‧N area

7a, 7b, 7c‧‧‧P ⁺ area

8‧‧‧ pixel selection line conductor layer

9a‧‧‧1st interlayer insulation

9b‧‧‧2nd interlayer insulation

9c‧‧‧Protective layer insulation

10a, 10b, 10c‧‧‧ Photodiode region

L7a‧‧‧P ⁺ thickness of zone 7a

Thickness of L7b‧‧‧P ⁺ zone 7b

Thickness of L7c‧‧‧P ⁺ zone 7c

LG‧‧‧ height of conductor layer 5

Claims (8)

In a solid-state imaging device, a plurality of pixels include an island-shaped semiconductor and are arranged in a two-dimensional shape in a pixel region, and the solid-state imaging device includes a first semiconductor region formed on a substrate, and formed on the first semiconductor region In the mother semiconductor region constituting the island-shaped semiconductor, a second semiconductor region is formed on an outer peripheral portion of the mother semiconductor region spaced apart from the first semiconductor region, and the second semiconductor region forms the mother semiconductor region and the diode region. The upper portion of the second semiconductor region is formed to have a third semiconductor region having a conductivity type opposite to the second semiconductor region so as to be in contact with the mother semiconductor region, and the third semiconductor region includes a signal charge sufficient for An amount of the acceptor impurity or the donor impurity that is re-coupled and disappeared in the third semiconductor region, and the signal charge is generated by the incident light that is incident from the upper end surface of the island-shaped semiconductor by the third semiconductor region, and the island shape is generated. The semiconductor is in a manner of including at least two of the above-described third semiconductor regions having different thicknesses The island-shaped semiconductor is formed on the third semiconductor region of the first island-shaped semiconductor having the thinnest third semiconductor region or the second island semiconductor having the second thin semiconductor region having a thickness Forming a primary color filter or a complementary color color filter, the light having passed through the color filter includes the following wavelengths of light The light-wavelength component is subjected to light absorption and signal charge storage in the diode region located in the first island-shaped semiconductor or the second island-shaped semiconductor below the color filter, and the solid-state imaging device is photographed. The operation includes: a photoelectric conversion operation of absorbing a light incident from a surface of an upper end portion of the island-shaped semiconductor in a diode region including the second semiconductor region and the mother semiconductor region to generate a signal charge; and a signal charge storage operation The generated signal charge is stored in the diode region; the stored signal charge reading operation detects the signal stored in the diode region by detecting the source drain current flowing through the junction field effect transistor The charge amount, the junction field effect transistor has one of the first semiconductor region and the third semiconductor region as a source or a drain, and the second semiconductor region as a gate, and the second semiconductor The above-mentioned parent semiconductor region surrounded by the region serves as a channel; and a signal charge removing operation electrically charges the signal stored in the diode region The charge is removed in the first semiconductor region. The solid-state imaging device according to claim 1, wherein the first island-shaped semiconductor has the third semiconductor region through which blue wavelength light, green wavelength light, and red wavelength light incident from the upper end surface are transmitted. The second island-shaped semiconductor has the third semiconductor region that absorbs blue wavelength light incident from the upper end surface. The solid-state imaging device further includes a third island-shaped semiconductor, and the third island-shaped semiconductor has the third semiconductor region that absorbs blue wavelength light and green wavelength light incident from the upper end surface of the island-shaped semiconductor, and the first island The diode region of the semiconductor is subjected to photoelectric conversion of blue wavelength light, green wavelength light, and red wavelength light incident from the upper end surface of the first island-shaped semiconductor, and storage of signal charges by the photoelectric conversion described above. 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 storage of signal charges by the photoelectric conversion, and the third The diode region of the island-shaped semiconductor performs photoelectric conversion of red wavelength light incident from the upper end surface of the third island-shaped semiconductor and storage of signal charges by the photoelectric conversion, and the first island-shaped semiconductor The thickness of the semiconductor region is thinner than the thickness of the third semiconductor region of the second island-shaped semiconductor, and the second island The thickness of the third semiconductor region of the semiconductor is thinner 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 adjacent to each other Formed by the way. The solid-state imaging device according to claim 2, wherein the color filter of the primary color or the complementary color is formed on either the first island-shaped semiconductor or the second island-shaped semiconductor. And including light wavelength components in the light that has passed through the color filter, and the light wavelength component is in place Light absorption and signal charge storage are performed in the first island-shaped semiconductor below the color filter or in the diode region in the second island-shaped semiconductor. The solid-state imaging device according to claim 1, wherein the first island-shaped semiconductor in which a color filter for transmitting blue wavelength light is formed in the upper portion is formed in the pixel region, and an upper portion is not formed. The first island-shaped semiconductor of the color filter that transmits the blue-wavelength light, and the first island-shaped semiconductor that does not form the color filter that transmits the blue-wavelength light from the upper portion, and includes a blue wavelength A white signal current of a light component, a green wavelength light component, and a red wavelength light component. The solid-state imaging device according to claim 1, wherein the island-shaped semiconductor comprises: a fourth island-shaped semiconductor having a diode region, wherein the diode region has a blue wavelength that has passed through the third semiconductor region Photoelectric conversion of light, green wavelength light and red wavelength light, and storage of signal charges by the above photoelectric conversion; and a fifth island-shaped semiconductor having a diode region through which the diode region has passed through the third semiconductor region The photoelectric conversion of one or both of the green wavelength light and the red wavelength light, and the storage of the signal charge by the photoelectric conversion, the thickness of the third semiconductor region of the fifth island-shaped semiconductor is equal to or thicker than The thickness of the third semiconductor region of the fourth island-shaped semiconductor forms a sixth island-shaped semiconductor in the pixel region, and the sixth island-shaped semiconductor has the fourth island-shaped semiconductor and the fifth island-shaped semiconductor. The same structure of the second semiconductor region and the third semiconductor region in the middle, A primary color or complementary color filter is formed on the sixth island-shaped semiconductor, and the fourth island semiconductor, the fifth island semiconductor, and the sixth island semiconductor are formed adjacent to each other. The solid-state imaging device according to claim 1, wherein the island-shaped semiconductor comprises: a seventh island-shaped semiconductor having a diode region, wherein the diode region has a blue wavelength that has passed through the third semiconductor region Photoelectric conversion of light, green wavelength light and red wavelength light, and storage of signal charges obtained by the above photoelectric conversion; and an eighth island semiconductor having a diode region through which the above-mentioned diode region has been transmitted (3) photoelectric conversion of green wavelength light and red wavelength light in the semiconductor region, and storage of signal charges by the photoelectric conversion, the thickness of the third semiconductor region of the eighth island-shaped semiconductor is formed to be larger than that of the seventh island-shaped semiconductor The thickness of the third semiconductor region is thick, and a ninth island-shaped semiconductor is formed in the pixel region, and the ninth island-shaped semiconductor has the second semiconductor among the seventh island-shaped semiconductor and the eighth island-shaped semiconductor. a region having the same structure as the third semiconductor region, and a primary color or complementary 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 of claim 1, wherein An insulating layer that transmits light is formed between the substrate and the first semiconductor region, and a thickness of the insulating layer is set as follows: a light incident from a surface of an upper end portion of the island-shaped semiconductor is returned from the insulating layer to the island The light in the above-described diode region of the semiconductor is more red than the green wavelength component. The solid-state imaging device according to claim 1, wherein in the pixel region, the third semiconductor region is at least two island-shaped semiconductors having different thicknesses arranged in a zigzag or checkerboard shape.