WO2019176518A1

WO2019176518A1 - Imaging device and production method for imaging device

Info

Publication number: WO2019176518A1
Application number: PCT/JP2019/007161
Authority: WO
Inventors: 田渕　清隆
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2018-03-16
Filing date: 2019-02-26
Publication date: 2019-09-19

Abstract

This imaging device is provided with: a semiconductor substrate which has a light receiving surface and which is equipped with a photoelectric conversion unit; and a wiring layer which is disposed so as to face the semiconductor substrate and which includes a wiring and an insulating first oxide film, wherein the first oxide film contains heavy water.

Description

Imaging apparatus and manufacturing method of imaging apparatus

The present disclosure relates to an imaging device having a semiconductor substrate and a wiring layer, and a manufacturing method thereof.

The imaging apparatus has, for example, a semiconductor substrate, and a photoelectric conversion unit is provided for each pixel on the semiconductor substrate. This semiconductor substrate is composed of, for example, a Si (silicon) substrate. There are dangling bonds (unbonded hands) of atoms in the semiconductor substrate (see, for example, Patent Document 1).

JP 2013-243261 A

In such an imaging apparatus, it is desired to suppress the generation of noise due to dangling bonds.

Therefore, it is desirable to provide an imaging apparatus capable of suppressing the generation of noise due to dangling bonds and a method for manufacturing the same.

An imaging apparatus (1) according to an embodiment of the present disclosure has a light receiving surface, a semiconductor substrate provided with a photoelectric conversion unit, a semiconductor substrate provided opposite to the semiconductor substrate, and a wiring and an insulating first oxide A wiring layer including a film, and the first oxide film includes heavy water.

In the imaging device (1) according to the embodiment of the present disclosure, since the first oxide film contains heavy water, for example, deuterium or tritium is generated in the first oxide film by heat treatment, and this deuterium or tritium is generated. Diffuses into the semiconductor substrate.

An imaging device (2) according to an embodiment of the present disclosure has a light receiving surface, a semiconductor substrate provided with a photoelectric conversion unit, a semiconductor substrate provided opposite to the semiconductor substrate, and a wiring and an insulating first oxide And a wiring layer including a film, wherein the first oxide film includes an OH group having a concentration of 2 × 10 ²⁰ cm ³ or more.

In the imaging device (2) according to the embodiment of the present disclosure, since the first oxide film includes OH groups having a concentration of 2 × 10 ²⁰ cm ³ or more, for example, hydrogen is generated in the first oxide film by heat treatment, This hydrogen diffuses into the semiconductor substrate.

According to an imaging device manufacturing method according to an embodiment of the present disclosure, a photoelectric conversion unit is formed on a semiconductor substrate, and a wiring layer including a wiring and an insulating first oxide film is formed on the semiconductor substrate. The oxide film contains water or heavy water, and the first oxide film containing water or heavy water is subjected to heat treatment.

In the method for manufacturing an imaging device according to an embodiment of the present disclosure, heat treatment is performed on the first oxide film containing water or heavy water, and thus hydrogen, deuterium, or tritium is generated in the first oxide film. Hydrogen, deuterium or tritium diffuses into the semiconductor substrate.

According to the imaging devices (1), (2) and the manufacturing method thereof according to an embodiment of the present disclosure, hydrogen, deuterium, or tritium is diffused in the semiconductor substrate. Thus, the dangling bond can be terminated. Therefore, it is possible to suppress the generation of noise due to dangling bonds.

The above content is an example of the present disclosure. The effects of the present disclosure are not limited to those described above, and may be other different effects or may include other effects.

It is a plane mimetic diagram showing a schematic structure of an imaging device concerning one embodiment of this indication. It is a schematic diagram showing the cross-sectional structure of the pixel area | region of the imaging device shown in FIG. FIG. 2 is a diagram illustrating an FT-IR (Fourier Transform Infrared) spectrum of the first oxide film illustrated in FIG. 1. FIG. 3B is an enlarged view showing the vicinity of 3700 cm ⁻¹ of the FT-IR spectrum shown in FIG. 3A. FIG. 6 is a schematic cross-sectional view illustrating another example of the second oxide film illustrated in FIG. 2. It is a cross-sectional schematic diagram showing 1 process of the manufacturing method of the imaging device shown in FIG. It is a cross-sectional schematic diagram showing the process following FIG. 5A. It is a cross-sectional schematic diagram showing the process following FIG. 5B. It is a cross-sectional schematic diagram showing the process following FIG. 5C. It is a cross-sectional schematic diagram showing the process following FIG. 5D. It is a cross-sectional schematic diagram showing the process following FIG. 5E. It is a cross-sectional schematic diagram showing the process following FIG. 5F. FIG. 7 is a schematic cross-sectional view in the vicinity of a pixel separation groove representing a step following FIG. 6. FIG. 7 is a schematic cross-sectional view of the vicinity of the surface of a semiconductor substrate illustrating a process following FIG. 6. FIG. 8 is a diagram showing a degassing spectrum from a second oxide film in each step of FIGS. 5F to 7B. FIG. 8 is a diagram showing SIMS (Secondary / Ion / Mass / Spectroscopy) of each step of FIGS. 6 to 7B. It is a cross-sectional schematic diagram showing an example of a structure of the imaging device which concerns on a modification. It is a functional block diagram showing an example of the electronic device (camera) using the imaging device shown in FIG. It is a block diagram which shows an example of a schematic structure of an in-vivo information acquisition system. It is a figure which shows an example of a schematic structure of an endoscopic surgery system. It is a block diagram which shows an example of a function structure of a camera head and CCU. It is a block diagram which shows an example of a schematic structure of a vehicle control system. It is explanatory drawing which shows an example of the installation position of a vehicle exterior information detection part and an imaging part.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The order of explanation is as follows.
1. Embodiment (imaging device in which first oxide film contains water or heavy water)
2. Modified example (example having a plurality of stacked semiconductor chips)
3. Application Example 4 Application examples

<Embodiment>
[Configuration of Imaging Device 1]
FIG. 1 schematically illustrates an example of a planar configuration of a solid-state imaging device (imaging device 1) according to an embodiment of the present disclosure. The imaging device 1 is, for example, a backside illumination type CMOS (Complementary Metal Oxide Semiconductor) image sensor, and has sensitivity to light having a wavelength in the visible region, for example. This imaging device 1 is provided with, for example, a rectangular pixel area 110A and an outside pixel area 110B outside the pixel area 110A. A peripheral circuit unit 130 for driving the pixel region 110A is provided in the outside pixel region 110B.

The pixel region 110A of the imaging device 1 is provided with a plurality of light receiving unit regions (pixels P) that are two-dimensionally arranged, for example. The peripheral circuit unit 130 provided in the outside-pixel region 110B includes, for example, a row scanning unit 131, a horizontal selection unit 133, a column scanning unit 134, and a system control unit 132.

Also, in the pixel P, for example, a pixel drive line Lread (for example, a row selection line and a reset control line) is wired for each pixel row, and a vertical signal line Lsig is wired for each pixel column (FIG. 1). The pixel drive line Lread transmits a drive signal for reading a signal from the pixel P. One end of the pixel drive line Lread is connected to an output end corresponding to each row of the row scanning unit 131.

The row scanning unit 131 includes a shift register, an address decoder, and the like, and is a pixel driving unit that drives each pixel P in the pixel region 110A, for example, in units of rows. A signal output from each pixel P in the pixel row selected and scanned by the row scanning unit 131 is supplied to the horizontal selection unit 133 through each of the vertical signal lines Lsig. The horizontal selection unit 133 is configured by an amplifier, a horizontal selection switch, and the like provided for each vertical signal line Lsig.

The column scanning unit 134 includes a shift register, an address decoder, and the like, and drives the horizontal selection switches in the horizontal selection unit 133 in order while scanning. By the selective scanning by the column scanning unit 134, the signal of each pixel transmitted through each of the vertical signal lines Lsig is sequentially output to the horizontal selection unit 133, and is input to the signal processing unit (not shown) through the horizontal selection unit 133. The

The system control unit 132 receives a clock given from the outside, data for instructing an operation mode, and the like, and outputs data such as internal information of the imaging apparatus 1. The system control unit 132 further includes a timing generator that generates various timing signals. The row scanning unit 131, the horizontal selection unit 133, the column scanning unit 134, and the like are based on the various timing signals generated by the timing generator. Drive control is performed.

Next, a specific configuration of the pixel region 110A will be described.

FIG. 2 illustrates a schematic cross-sectional configuration of the pixel region 110A of the imaging device 1. FIG. 2 shows three pixels P. The imaging device 1 includes a semiconductor substrate 11 having a light receiving surface S1 (back surface) and a wiring layer 20 provided on a surface (surface S2) opposite to the light receiving surface S1 of the semiconductor substrate 11. The wiring layer 20 facing the semiconductor substrate 11 is a multilayer wiring layer, and includes a plurality of wirings 21 and a first oxide film 22. The imaging device 1 has a light shielding film 33, a planarizing film 32, a color filter 34, and an on-chip lens 35 on the light receiving surface S 1 of the semiconductor substrate 11 via the second oxide film 14 and the protective film 17. The imaging device 1 includes a support substrate 41 that faces the semiconductor substrate 11 with the wiring layer 20 in between.

In the light receiving surface S1 of the semiconductor substrate 11, a pixel separation groove 11A is provided with a predetermined depth. In the semiconductor substrate 11, a PD (Photo Diode) 12 (photoelectric conversion unit) is provided for each pixel P.

The semiconductor substrate 11 is made of, for example, p-type silicon (Si). A pixel separation groove 11A extending from the light receiving surface S1 in the thickness direction of the semiconductor substrate 11 (Z direction in FIG. 2) is provided between adjacent pixels P. The pixel separation groove 11A has, for example, a lattice-like planar shape and is arranged so as to surround the pixel P. For example, the pixel separation groove 11A is disposed at a position overlapping a floating diffusion (FD) 13 described later in plan view (XY plane in FIG. 1). The depth of the pixel isolation groove 11 A may be a depth that can suppress crosstalk, and is a depth that does not penetrate the semiconductor substrate 11.

In the vicinity of the surface S2 of the semiconductor substrate 11, a transfer transistor for transferring the signal charge generated in the PD 12 to, for example, the vertical signal line Lsig (FIG. 1) is arranged. The transfer transistor includes, for example, the FD 13 and a gate electrode. The FD 13 is provided in the vicinity of the surface S 2 in the semiconductor substrate 11. The FD 13 is an n-type semiconductor region formed by implanting an n-type impurity at a high concentration into a p-well layer 11y (see FIG. 5B described later) of the semiconductor substrate 11. The gate electrode is included in the wiring layer 20, for example. The signal charge may be either an electron or a hole generated by photoelectric conversion. Here, a case where an electron is read as a signal charge will be described as an example.

In the vicinity of the surface S2 of the semiconductor substrate 11, for example, a reset transistor, an amplification transistor, and a selection transistor are provided along with the transfer transistor. Such a transistor is, for example, a MOSEFT (Metal Oxide Semiconductor Field Effect Transistor), and constitutes a pixel circuit for each pixel P. Each pixel circuit may have a three-transistor configuration including, for example, a transfer transistor, a reset transistor, and an amplification transistor, or may have a four-transistor configuration in which a selection transistor is added thereto. Transistors other than the transfer transistor can be shared between pixels.

PD 12 is, for example, an n-type semiconductor region formed in the thickness direction (Z direction) of the semiconductor substrate 11 (here, Si substrate) for each pixel P. The PD 12 is a so-called pn junction type photodiode having a p-type semiconductor region provided in the vicinity of the front surface and the back surface of the semiconductor substrate 11 and a pn junction. The semiconductor substrate 11 is also provided with a p-type semiconductor region (p-type layer 11x, p-well layer 11y, for example, see FIG. 5B described later) between the pixels P. The pixel isolation trench 11A is formed in this p-type semiconductor region. If the pixel isolation trench 11A is formed in the p-type semiconductor region, the tip of the pixel isolation trench does not necessarily need to reach the p-well layer 11y formed around the FD 13, and sufficient in the p-type layer 11x. An inter-pixel isolation effect is obtained.

The plurality of wirings 21 included in the wiring layer 20 constitute, for example, a pixel circuit, a pixel driving line Lread, a vertical signal line Lsig, and the like in addition to the gate electrode of the transistor. The first oxide film 22 has an insulating property and functions as, for example, an interlayer insulating film that separates the plurality of wirings 21. The first oxide film 22 is made of, for example, an oxide film containing Si (silicon). Specifically, the first oxide film 22 is composed of a SiO (silicon oxide) film, a TEOS (Tetra Ethyl Ortho Silicate) film, or the like. In the present embodiment, the first oxide film 22 contains heavy water. This heavy water is D ₂ O or T ₂ O. Although details will be described later, for example, heat treatment is performed on the first oxide film 22 containing heavy water to generate D ₂ (deuterium) or T ₂ (tritium) in the first oxide film 22. This D ₂ or T ₂ diffuses into the semiconductor substrate 11 and terminates dangling bonds.

Alternatively, the first oxide film 22 may contain H ₂ O (water), and the concentration of OH groups contained in the first oxide film 22 may be 2 × 10 ²⁰ cm ³ or more. Also in this case, for example, heat treatment is performed on the first oxide film 22 containing water to generate H ₂ (hydrogen) in the first oxide film 22, and this H ₂ diffuses into the semiconductor substrate 11 and is dangling. Terminate the bond.

3A and 3B show an example of an FT-IR (Fourier Transform Infrared) transmission spectrum of the first oxide film 22. FIG. 3B shows an enlarged view of the vicinity of 3700 cm ⁻¹ in FIG. 3A. The first oxide film 22 is an oxide film of Si, has an absorption peak derived from Si-O in the vicinity of 1100 cm ^-1, and an absorption peak derived from O-H in the vicinity of 3700 cm ^-1. The concentration of OH groups contained in the first oxide film 22 can be obtained by using the absorbance (A) of the absorption peak derived from OH near 3700 cm ⁻¹ .

Specifically, the concentration (c) may be obtained using the Lambert-Beer law expressed by the following equation (1).

A = εcl (1)

In the formula (1), A represents absorbance, ε represents molecular extinction coefficient, c represents concentration, and l represents sample thickness.

Absorbance A can be determined from the FT-IR transmission spectrum (FIG. 3B). For example, the molecular extinction coefficient ε of SiO ₂ is ε _OH = 77.5 cm ³ / (mol · cm) (J. E. Shelby, J. Appl. Phys. 50, 3702 (1979)). The thickness l of the sample can be obtained from measurement with an ellipsometer.

For example, the OH group concentration of the SiO film formed by PEALD (Plasma Enhanced Atomic Layer Deposition) is 2.20 × 10 ²⁰ cm ³ , and the SiO film formed by PECDV (Plasma Enhanced Chemical Vapor Deposition) is used. The concentration of OH groups in the TEOS film formed by PECDV method is 1.0 × 10 ²¹ cm ³ , and the concentration of OH groups in the TECD film is 1.0 × 10 ²¹ cm ³ , and HDP (High Density Plasma) The concentration of OH groups in the SiO film formed by the method is 2.0 × 10 ²¹ cm ³ .

The wiring layer 20 may include a plurality of first oxide films 22, or the wiring layer 20 may include the first oxide film 22 and another insulating film. Examples of the other insulating film include a SiN (silicon nitride) film. The thickness of the first oxide film 22 is, for example, 20 nm to 3000 nm.

The insulating second oxide film 14 covering the light receiving surface S1 of the semiconductor substrate 11 covers the inner wall surface (side wall and bottom surface) of the pixel isolation trench 11A together with the light receiving surface S1. The second oxide film 14 is made of an insulating oxide film containing, for example, Si (silicon). Specifically, the second oxide film 14 is composed of a SiO ₂ (silicon oxide) film, a TEOS (Tetra Ethyl Ortho Silicate) film, or the like. Like the first oxide film 22, the second oxide film 14 preferably contains heavy water. Thereby, since D ₂ or T ₂ is diffused also from the light receiving surface S1 of the semiconductor substrate 11, the dangling bonds can be terminated more effectively. Further, the dangling bond is effectively terminated by providing the second oxide film 14 in the vicinity of the pixel isolation trench 11A having many defects. The thickness of the second oxide film 14 is, for example, 20 nm to 500 nm.

Alternatively, the second oxide film 14 may contain H ₂ O (water), and the concentration of OH groups contained in the second oxide film 14 may be 2 × 10 ²⁰ cm ³ or more. Also in this case, for example, by performing a heat treatment on the second oxide film 14 containing water, H ₂ (hydrogen) is generated in the second oxide film 14, and this H ₂ diffuses into the semiconductor substrate 11 and is dangling. Terminate the bond. The concentration of OH groups can be obtained by the same method as described for the first oxide film 22.

FIG. 4 shows another example of the configuration of the second oxide film 14. As described above, the second oxide film 14 may be selectively disposed in the vicinity of the pixel isolation trench 11A, and the second oxide film 14 immediately above the PD 12 may be removed. By providing the second oxide film 14 containing heavy water or water in a selective region, generation of excess D ₂ , T _2, or H ₂ can be suppressed.

The second oxide film 14 may have a laminated structure, or another insulating film may be provided between the second oxide film 14 and the protective film 17. Examples of the other insulating film include a SiN (silicon nitride) film.

The protective film 17 covers the light receiving surface S1 of the semiconductor substrate 11 with the second oxide film 14 therebetween. The protective film 17 planarizes the light receiving surface S1 of the semiconductor substrate 11. For example, the protective film 17 is embedded in the pixel isolation trench 11 A together with the second oxide film 14. The protective film 17 is composed of a single layer film such as silicon nitride (Si ₂ N ₃ ), silicon oxide (SiO ₂ ), and silicon oxynitride (SiON) or a laminated film thereof. The thickness of the protective film 17 is preferably 0.05 μm or more and 0.30 μm or less, for example.

The light shielding film 33 provided on the protective film 17 is provided between adjacent pixels P. Specifically, the light shielding film 33 is provided at a position overlapping the pixel separation groove 11A in plan view, and extends into the pixel separation groove 11A. By providing the light shielding film 33, it is possible to suppress color mixing due to crosstalk of obliquely incident light between adjacent pixels P and to suppress generation of optical color mixing between adjacent pixels P. The light shielding film 33 is made of, for example, tungsten (W), aluminum (Al), an alloy of Al and copper (Cu), or the like, and has a film thickness of, for example, 20 nm to 5000 nm.

The planarizing film 32 covers the light shielding film 33 and the protective film 17 and planarizes the light receiving surface S 1 of the semiconductor substrate 11. The planarizing film 32 is formed of a single layer film such as silicon nitride (Si ₂ N ₃ ), silicon oxide (SiO ₂ ), and silicon oxynitride (SiON) or a laminated film thereof.

The color filter 34 covers the light receiving surface S1 of the semiconductor substrate 11 with the planarizing film 32 therebetween. The color filter 34 is, for example, one of a red (R) filter, a green (G) filter, a blue (B) filter, and a white filter (W), and is provided for each pixel P, for example. These color filters 34 are provided in a regular color arrangement (for example, a Bayer arrangement). By providing such a color filter 34, the imaging device 1 can obtain light reception data of a color corresponding to the color arrangement.

The on-chip lens 35 on the color filter 34 is provided at a position facing each PD 12 of each pixel P. The light incident on the on-chip lens 35 is condensed on the PD 12 for each pixel P. The lens system of the on-chip lens 35 is set to a value corresponding to the size of the pixel P, and is, for example, 0.05 μm or more and 1.00 μm or less. Further, the refractive index of the on-chip lens 35 is, for example, not less than 1.4 and not more than 2.0. Examples of the lens material include an organic material and a silicon oxide film (SiO ₂ ).

The support substrate 41 supports the surface S2 of the semiconductor substrate 11 with the wiring layer 20 therebetween. The support substrate 41 is for securing the strength of the semiconductor substrate 11 at the manufacturing stage, and is constituted by, for example, a silicon (Si) substrate.

(Manufacturing method of the imaging device 1)
Such an imaging apparatus 1 can be manufactured, for example, as follows (FIGS. 5A to 7B).

First, as shown in FIG. 5A, a semiconductor substrate 11 made of, for example, a Si substrate is prepared. Next, after forming the wiring layer 20 on the surface S2 side of the semiconductor substrate 11, impurity semiconductor regions (n-type semiconductor region PD12, p-type semiconductor region 11x, and p-well layer 11y) are formed by ion implantation into the semiconductor substrate 11. (FIG. 5B). The wiring layer 20 is preferably formed under conditions that enhance the hygroscopicity of the first oxide film 22. For example, the first oxide film 22 is formed by forming a SiO film at a film formation temperature of 300 ° C. to 400 ° C. using PECVD. The first oxide film 22 may be formed by forming a TEOS film at a film forming temperature of 300 ° C. to 400 ° C. using PECVD. The PECVD method is a CCP (Capacitively Coupled Plasma) plasma CVD method, but an ICP (Inductivity Coupled Plasma) plasma CVD method may be used. Examples of the ICP plasma CVD method include an HDP-CVD method. Alternatively, the first oxide film 22 may be formed using a thermal CVD method or the like. As the impurity semiconductor region, an n-type semiconductor region (PD12) is formed at a position corresponding to each pixel P, and a p-type semiconductor region is formed between adjacent pixels P.

After forming the first oxide film 22, as shown in FIG. 5C, the first oxide film 22 contains water or heavy water. The semiconductor substrate 11 and the wiring layer 201 may be immersed in water or heavy water. Alternatively, the semiconductor substrate 11 and the wiring layer 20 may be exposed to a water vapor atmosphere or a heavy water atmosphere. For example, using a mask, water or heavy water may be contained in a selective region of the first oxide film 22. This mask may be made of a material that hardly contains water or heavy water and does not allow water or heavy water to pass therethrough. For example, the mask can be formed using silicon nitride (SiN) or the like. Before forming the impurity semiconductor region in the semiconductor substrate 11, the first oxide film 22 may contain water or heavy water.

After the first oxide film 22 contains water or heavy water, the support substrate 41 is bonded to the surface S2 of the semiconductor substrate 11 with the wiring layer 20 therebetween as shown in FIG. 5D. Subsequently, as shown in FIG. 5E, pixel separation is performed, for example, by dry etching in a predetermined position of the light receiving surface S1 of the semiconductor substrate 11, specifically, in a P-type semiconductor region provided between adjacent pixels P. A groove 11A is formed.

Next, as shown in FIG. 5F, the second oxide film 14 is formed on the light receiving surface S1 of the semiconductor substrate 11 and the inner wall surface of the pixel isolation trench 11A. The second oxide film 14 is preferably formed under conditions that enhance the hygroscopicity of the second oxide film 14. Specifically, this is the same as described for the first oxide film 22. For example, the second oxide film 14 can be formed by forming a SiO film at a film forming temperature of 300 ° C. to 400 ° C. using PECVD. The second oxide film 14 may be formed by forming a TEOS film at a film formation temperature of 300 ° C. to 400 ° C. using PECVD. The second oxide film 14 may be formed using an ICP plasma CVD method or a thermal CVD method.

After the second oxide film 14 is formed, water or heavy water is contained in the second oxide film 14 as shown in FIG. The second oxide film 14, the semiconductor substrate 11, the wiring layer 20, and the support substrate 41 may be immersed in water or heavy water. Alternatively, the second oxide film 14, the semiconductor substrate 11, the wiring layer 20, and the support substrate 41 may be exposed to a water vapor atmosphere or a heavy water atmosphere. For example, using a mask, water or heavy water may be contained in a selective region of the second oxide film 14. This mask may be made of a material that hardly contains water or heavy water and does not allow water or heavy water to pass therethrough. For example, the mask can be formed using silicon nitride (SiN) or the like.

After the first oxide film 22 and the second oxide film 14 contain water or heavy water, heat treatment is performed at a temperature of 300 ° C. or higher, for example. As a result, a Si (silicon) —O (oxygen) cross-linking reaction (formula (2)) by water or heavy water occurs in the first oxide film 22 and the second oxide film 14.

Si—Si + H ₂ O (D ₂ O, T ₂ O) → Si—O—Si + H ₂ (D ₂ , T ₂ ) (2)

H ₂ , D ₂ or T ₂ generated in the first oxide film 22 and the second oxide film 14 due to this crosslinking reaction diffuses into the semiconductor substrate 11 as shown in FIGS. 7A and 7B. For example, H ₂ , D _2, or T ₂ generated in the second oxide film 14 diffuses into the semiconductor substrate 11 through the light receiving surface S1 and the pixel isolation trench 11A (FIG. 7A), and in the first oxide film 22. The generated H ₂ , D ₂ or T ₂ diffuses into the semiconductor substrate 11 via the surface S2 (FIG. 7B). Thereby, the dangling bond of the semiconductor substrate 11 is terminated.

FIG. 8 shows a degassing spectrum of M / z = 20 (D ₂ O, etc.) from the second oxide film 14 in the steps of FIGS. 5F, 6 and 7A, 7B. In the step of FIG. 6 (step of immersing in heavy water), degassing of M / z = 20 is increased, and it can be confirmed that the second oxide film 14 contains heavy water. In the process (heat treatment process) of FIGS. 7A and 7B, degassing of M / z = 20 can hardly be confirmed.

FIG. 9 shows the results of SIMS (Secondary / Ion / Mass / Spectroscopy) of each step of FIGS. 6 and 7A and 7B. The solid line represents the concentration of deuterium (D), and the broken line represents the secondary ion intensity of silicon (Si). In the process of FIG. 6, deuterium is confirmed in the second oxide film 14, whereas in the processes of FIGS. 7A and 7B, it can be seen that deuterium has moved into the semiconductor substrate 11.

In the heat treatment after the first oxide film 22 and the second oxide film 14 contain water or heavy water, another insulating film (for example, a SiN film) is stacked on the first oxide film 22 or the second oxide film 14. You may make it carry out in the state performed. A heat treatment may be performed immediately after the first oxide film 22 contains water or heavy water, and the second oxide film 14 may be formed after the heat treatment.

After the heat treatment, the protective film 17 is formed on the light receiving surface S1 of the semiconductor substrate 11 and the inner wall surface of the pixel separation groove 11A. The protective film 17 is formed, for example, by forming a SiO ₂ film using the CVD method. Subsequently, a light shielding film 33 is formed on the protective film 17 and in the pixel separation groove 11A. Next, a planarizing film 32 is formed on the protective film 17 and the light shielding film 33. Thereafter, for example, a Bayer array color filter 34 and an on-chip lens 35 are sequentially formed on the planarizing film 32. In this way, the imaging device 1 is formed.

(Operation of the imaging apparatus 1)
In such an imaging apparatus 1, for example, signal charges (here, electrons) are acquired as follows. When the light L passes through the on-chip lens 35 and the color filter 34 and enters the light receiving surface S1 of the semiconductor substrate 11, the light L is detected (absorbed) by the PD 12 of each pixel P, and red, green, or blue color light. Is photoelectrically converted. Of the electron-hole pairs generated in the PD 12, electrons move to the semiconductor substrate 11 (for example, an n-type semiconductor region in the Si substrate) and accumulate, and holes move to the p-type region and are discharged.

(Operation / Effect of Imaging Device 1)
In the present embodiment, the first oxide film 22 and the second oxide film 14 contain water or heavy water. As described above, the first oxide film 22 and the second oxide film 14 are subjected to heat treatment after containing water or heavy water. As a result, H ₂ , D _2, or T ₂ is generated in the first oxide film 22 and the second oxide film 14, and this H ₂ , D _2, or T ₂ is diffused into the semiconductor substrate 11. The H ₂ , D ₂ or T ₂ diffused in the semiconductor substrate 11 mainly terminates dangling bonds in the vicinity of the interface (light receiving surface S1, surface S2) of the semiconductor substrate 11 and in the vicinity of the pixel separation groove 11A.

As a method for terminating the dangling bonds of the semiconductor substrate, a method of exposing the semiconductor substrate and the wiring layer to a deuterium atmosphere after forming the wiring layer can be considered. However, this method makes it difficult for deuterium to diffuse into the atmosphere and reach the semiconductor substrate interface.

On the other hand, in the imaging device 1 of the present embodiment, H ₂ , D _2, or T ₂ is generated in the first oxide film 22 and the second oxide film 14, so that H ₂ , D _2, or T ₂ is It is difficult to be released into the atmosphere and easily reaches the semiconductor substrate 11. Therefore, dangling bonds of the semiconductor substrate 11 can be terminated more effectively.

In addition, since D and T are twice or three times the mass number of H, even if there is a foreign matter adsorption or a disturbance such as thermal energy, between D ₂ and T ₂ bonded silicon atoms Bond dissociation hardly occurs. Therefore, D ₂ and T ₂ act more effectively at the end of Si and reduce the interface state.

As described above, in the present embodiment, since H ₂ , D ₂ or T ₂ is diffused into the semiconductor substrate 11, the dangling bond can be terminated by H ₂ , D ₂ or T ₂ . Therefore, it is possible to suppress the generation of noise due to dangling bonds.

Since the first oxide film 22 is provided on the surface S2 of the semiconductor substrate 11 and the second oxide film 14 is provided on the light receiving surface S1 of the semiconductor substrate 11, H ₂ , D ₂ or T ₂ is diffused. Therefore, dangling bonds can be terminated more effectively. In particular, in the backside illumination type imaging device 1, since the distance between the second oxide film 14 and the light receiving surface S 1 of the semiconductor substrate 11 is short, H ₂ , D ₂ or T ₂ is transferred from the second oxide film 14 to the semiconductor substrate 11. Effectively supplied.

Further, since defects are likely to occur in the vicinity of the pixel separation groove 11A provided in the semiconductor substrate 11, a dangling bond can be effectively formed by providing the second oxide film 14 on the inner wall surface of the pixel separation groove 11A. Can be terminated. Therefore, the present technology is suitable for an imaging device having a digging structure such as the pixel separation groove 11A.

Hereinafter, modifications of the above embodiment will be described. In the following description, the same components as those of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

<Modification>
FIG. 10 illustrates a schematic cross-sectional configuration of a main part of the imaging device 2. The imaging device 2 includes a semiconductor chip 211, a semiconductor chip 212, and a semiconductor chip 213 in this order, and these are stacked on each other. The imaging device 2 is, for example, a backside illumination type CMOS image sensor.

The semiconductor chip 211 is provided with a sensor circuit, for example. For example, a logic circuit is provided in the semiconductor chip 212. For example, a memory circuit is provided in the semiconductor chip 213. Each of the logic circuit and the memory circuit is configured to operate with input / output of signals from / to the outside.

The semiconductor chip 211 has a semiconductor substrate, and a photodiode (PD) 234 serving as a photoelectric conversion portion of the pixel is provided on the semiconductor substrate. In the semiconductor well region of this semiconductor substrate, source / drain regions of each pixel transistor are provided.

The semiconductor chip 211 has pixel transistors Tr1 and Tr2 on the surface of the semiconductor substrate. Each of the pixel transistors Tr1, Tr2 has a gate electrode and a pair of source / drain regions. A gate insulating film is provided between the surface of the semiconductor substrate and the gate electrode.

The pixel transistor Tr1 adjacent to the photodiode (PD) 234 corresponds to a transfer transistor, and its source / drain region corresponds to a floating diffusion (FD).

The semiconductor chip 211 has an interlayer insulating film. A plurality of connection conductors 244 are provided on the interlayer insulating film. The connection conductors 244 are connected to the pixel transistors Tr1 and Tr2, respectively.

The semiconductor chip 211 has a multilayer wiring layer 245 including a plurality of layers of metal wirings 240. At least a part of the metal wiring 240 is connected to the connection conductor 244. The metal wiring 240 is composed of, for example, a copper (Cu) wiring. Each copper wiring is covered with a barrier metal film, for example, to prevent Cu diffusion. On the multilayer wiring layer 245, for example, a protective film which is a cap film for copper wiring is provided.

In the lowermost layer (layer on the semiconductor chip 212 side) of the multilayer wiring layer 245, an aluminum pad 280 that is an electrode for external connection is provided. That is, the aluminum pad 280 is provided at a position closer to the bonding surface 291 with the semiconductor chip 212 than the metal wiring 240. This external connection electrode is used as one end of a wiring related to signal input / output with the outside. In addition, although demonstrated here as an electrode being formed with aluminum, you may make it form an electrode with another metal.

In this modification, for example, the multilayer wiring layer 245 has an insulating oxide film containing water or heavy water.

The semiconductor chip 211 is provided with a through electrode 265 used for electrical connection with the semiconductor chip 212. The through electrode 265 is connected to a through electrode 266 of the semiconductor chip 212 described later, and is also connected to an aluminum pad 280a. In this modification, for example, the inner wall surface of the through electrode 265 is covered with an insulating oxide film containing water or heavy water. This oxide film may be provided on the back surface (light receiving surface) of the semiconductor substrate.

In the semiconductor chip 211, a pad hole 351 is formed so as to reach the aluminum pad 280a from the back surface side (light receiving surface side) of the semiconductor chip 211.

The semiconductor chip 211 is provided with an insulating protective film on the entire back surface. A light shielding film is provided in the light shielding region of the back surface of the semiconductor chip 211. Further, the semiconductor chip 211 has an on-chip color filter 274 and an on-chip microlens 275 corresponding to each pixel on the planarizing film.

The semiconductor chip 212 provided between the semiconductor chip 211 and the semiconductor chip 213 includes a logic circuit. The semiconductor chip 211 has a semiconductor substrate, and MOS transistors Tr6, Tr7, Tr8 are provided in a p-type semiconductor well region of the semiconductor substrate. The logic circuit includes these MOS transistors Tr6, Tr7, Tr8.

The semiconductor chip 212 has a plurality of connection conductors 254. The connection conductor 254 is connected to MOS transistors Tr6, Tr7, Tr8.

The semiconductor chip 212 has a multilayer wiring layer 255 including a plurality of layers of metal wirings 250. Each metal wiring 250 is connected to the connection conductor 254.

The metal wiring 250 is composed of, for example, copper (Cu) wiring. A protective film which is a cap film for the metal wiring 250 is provided on the multilayer wiring layer 255.

In the lowermost layer (layer on the semiconductor chip 213 side) of the multilayer wiring layer 255, an aluminum pad 320 serving as an electrode is provided. That is, the aluminum pad 320 is provided at a position closer to the bonding surface 292 with the semiconductor chip 213 than to the metal wiring 250.

The semiconductor chip 212 has a through electrode 266, and the semiconductor chip 212 is electrically connected to the semiconductor chip 211 and the semiconductor chip 213 through the through electrode 266. The through electrode 266 is connected to the through electrode 265 of the semiconductor chip 211 and is also connected to the aluminum pad 330 a of the semiconductor chip 213.

The semiconductor chip 213 facing the semiconductor chip 211 with the semiconductor chip 212 in between includes a memory circuit. The semiconductor chip 213 has a semiconductor substrate, and MOS transistors Tr11, Tr12, Tr13 are provided in a p-type semiconductor well region of the semiconductor substrate. The memory circuit includes the MOS transistors Tr11, Tr12, Tr13.

The semiconductor chip 213 has a plurality of connection conductors 344. The connection conductor 344 is connected to MOS transistors Tr11, Tr12, Tr13.

The semiconductor chip 213 has a multilayer wiring layer 345 including a plurality of layers of metal wirings 340. Each metal wiring 340 is connected to the connection conductor 344.

The metal wiring 340 is composed of, for example, copper (Cu) wiring. A protective film that is a cap film for the metal wiring 340 is provided on the multilayer wiring layer 345.

An aluminum pad 330 serving as an electrode is provided on the uppermost layer of the multilayer wiring layer 345 (the layer on the semiconductor chip 212 side).

In this imaging device 2, since the through

electrodes

265 and 266 are provided, signals can be input and output between the

semiconductor chips

211, 212, and 213 through the aluminum pad 280a.

Similarly to the image pickup apparatus 1 of the above embodiment, the image pickup apparatus 2 of the present modification is also provided with oxide films containing water or heavy water on the front and back surfaces of the semiconductor substrate, so that H ₂ , D ₂ or T ₂ is diffused into the semiconductor substrate. Therefore, the dangling bond can be terminated by H ₂ , D ₂ or T ₂ .

<Application example>
The

imaging devices

1 and 2 can be applied to all types of electronic devices having an imaging function, such as a camera system such as a digital still camera and a video camera, and a mobile phone having an imaging function. FIG. 11 shows a schematic configuration of an electronic device 3 (camera) as an example. The electronic device 3 is, for example, a video camera capable of shooting a still image or a moving image, and drives the imaging device 2, an optical system (optical lens) 310, a shutter device 311, the imaging device 2 and the shutter device 311. A driving unit 313 and a signal processing unit 312 are included.

The optical system 310 guides image light (incident light) from the subject to the imaging device 2. The optical system 310 may be composed of a plurality of optical lenses. The shutter device 311 controls the light irradiation period and the light shielding period to the imaging device 2. The drive unit 313 controls the transfer operation of the imaging device 2 and the shutter operation of the shutter device 311. The signal processing unit 312 performs various signal processing on the signal output from the imaging device 2. The video signal Dout after the signal processing is stored in a storage medium such as a memory, or is output to a monitor or the like.

<Application example>
<Application example to in-vivo information acquisition system>
Furthermore, the technology (present technology) according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

FIG. 12 is a block diagram illustrating an example of a schematic configuration of a patient in-vivo information acquisition system using a capsule endoscope to which the technique according to the present disclosure (present technique) can be applied.

The in-vivo information acquisition system 10001 includes a capsule endoscope 10100 and an external control device 10200.

The capsule endoscope 10100 is swallowed by the patient at the time of examination. The capsule endoscope 10100 has an imaging function and a wireless communication function, and moves inside the organ such as the stomach and the intestine by peristaltic motion or the like until it is spontaneously discharged from the patient. Images (hereinafter also referred to as in-vivo images) are sequentially captured at predetermined intervals, and information about the in-vivo images is sequentially wirelessly transmitted to the external control device 10200 outside the body.

The external control device 10200 comprehensively controls the operation of the in-vivo information acquisition system 10001. Further, the external control device 10200 receives information about the in-vivo image transmitted from the capsule endoscope 10100 and, based on the received information about the in-vivo image, displays the in-vivo image on the display device (not shown). The image data for displaying is generated.

In the in-vivo information acquisition system 10001, an in-vivo image obtained by imaging the inside of the patient's body can be obtained at any time in this manner until the capsule endoscope 10100 is swallowed and discharged.

The configurations and functions of the capsule endoscope 10100 and the external control device 10200 will be described in more detail.

The capsule endoscope 10100 includes a capsule-type casing 10101. In the casing 10101, a light source unit 10111, an imaging unit 10112, an image processing unit 10113, a wireless communication unit 10114, a power supply unit 10115, and a power supply unit 10116 and the control unit 10117 are stored.

The light source unit 10111 includes a light source such as an LED (light-emitting diode), and irradiates the imaging field of the imaging unit 10112 with light.

The image capturing unit 10112 includes an image sensor and an optical system including a plurality of lenses provided in front of the image sensor. Reflected light (hereinafter referred to as observation light) of light irradiated on the body tissue to be observed is collected by the optical system and enters the image sensor. In the imaging unit 10112, in the imaging element, the observation light incident thereon is photoelectrically converted, and an image signal corresponding to the observation light is generated. The image signal generated by the imaging unit 10112 is provided to the image processing unit 10113.

The image processing unit 10113 is configured by a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and performs various types of signal processing on the image signal generated by the imaging unit 10112. The image processing unit 10113 provides the radio communication unit 10114 with the image signal subjected to signal processing as RAW data.

The wireless communication unit 10114 performs predetermined processing such as modulation processing on the image signal that has been subjected to signal processing by the image processing unit 10113, and transmits the image signal to the external control apparatus 10200 via the antenna 10114A. In addition, the wireless communication unit 10114 receives a control signal related to drive control of the capsule endoscope 10100 from the external control device 10200 via the antenna 10114A. The wireless communication unit 10114 provides a control signal received from the external control device 10200 to the control unit 10117.

The power feeding unit 10115 includes a power receiving antenna coil, a power regeneration circuit that regenerates power from a current generated in the antenna coil, a booster circuit, and the like. In the power feeding unit 10115, electric power is generated using a so-called non-contact charging principle.

The power supply unit 10116 is composed of a secondary battery, and stores the electric power generated by the power supply unit 10115. In FIG. 12, in order to avoid complication of the drawing, illustration of an arrow indicating a power supply destination from the power supply unit 10116 is omitted, but the power stored in the power supply unit 10116 is stored in the light source unit 10111. The imaging unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117 can be used for driving them.

The control unit 10117 includes a processor such as a CPU, and a control signal transmitted from the external control device 10200 to drive the light source unit 10111, the imaging unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the power feeding unit 10115. Control accordingly.

The external control device 10200 is configured by a processor such as a CPU or GPU, or a microcomputer or a control board in which a processor and a storage element such as a memory are mounted. The external control device 10200 controls the operation of the capsule endoscope 10100 by transmitting a control signal to the control unit 10117 of the capsule endoscope 10100 via the antenna 10200A. In the capsule endoscope 10100, for example, the light irradiation condition for the observation target in the light source unit 10111 can be changed by a control signal from the external control device 10200. In addition, an imaging condition (for example, a frame rate or an exposure value in the imaging unit 10112) can be changed by a control signal from the external control device 10200. Further, the contents of processing in the image processing unit 10113 and the conditions (for example, the transmission interval, the number of transmission images, etc.) by which the wireless communication unit 10114 transmits image signals may be changed by a control signal from the external control device 10200. .

Further, the external control device 10200 performs various image processing on the image signal transmitted from the capsule endoscope 10100, and generates image data for displaying the captured in-vivo image on the display device. As the image processing, for example, development processing (demosaic processing), image quality enhancement processing (band enhancement processing, super-resolution processing, NR (Noise reduction) processing and / or camera shake correction processing, etc.), and / or enlargement processing ( Various signal processing such as electronic zoom processing can be performed. The external control device 10200 controls driving of the display device to display an in-vivo image captured based on the generated image data. Alternatively, the external control device 10200 may cause the generated image data to be recorded on a recording device (not shown) or may be printed out on a printing device (not shown).

Heretofore, an example of the in-vivo information acquisition system to which the technology according to the present disclosure can be applied has been described. The technology according to the present disclosure can be applied to, for example, the imaging unit 10112 among the configurations described above. Thereby, detection accuracy improves.

<Application example to endoscopic surgery system>
The technology according to the present disclosure (present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

FIG. 13 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system to which the technology (present technology) according to the present disclosure can be applied.

FIG. 13 shows a state in which an operator (doctor) 11131 is performing an operation on a patient 11132 on a patient bed 11133 using an endoscopic operation system 11000. As shown in the figure, an endoscopic surgery system 11000 includes an endoscope 11100, other surgical instruments 11110 such as an insufflation tube 11111 and an energy treatment instrument 11112, and a support arm device 11120 that supports the endoscope 11100. And a cart 11200 on which various devices for endoscopic surgery are mounted.

The endoscope 11100 includes a lens barrel 11101 in which a region having a predetermined length from the distal end is inserted into the body cavity of the patient 11132, and a camera head 11102 connected to the proximal end of the lens barrel 11101. In the illustrated example, an endoscope 11100 configured as a so-called rigid mirror having a rigid lens barrel 11101 is illustrated, but the endoscope 11100 may be configured as a so-called flexible mirror having a flexible lens barrel. Good.

An opening into which the objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101. Irradiation is performed toward the observation target in the body cavity of the patient 11132 through the lens. Note that the endoscope 11100 may be a direct endoscope, a perspective mirror, or a side endoscope.

An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from the observation target is condensed on the image sensor by the optical system. Observation light is photoelectrically converted by the imaging element, and an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image is generated. The image signal is transmitted to a camera control unit (CCU: “Camera Control Unit”) 11201 as RAW data.

The CCU 11201 is configured by a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and the like, and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Further, the CCU 11201 receives an image signal from the camera head 11102 and performs various kinds of image processing for displaying an image based on the image signal, such as development processing (demosaic processing), for example.

The display device 11202 displays an image based on an image signal subjected to image processing by the CCU 11201 under the control of the CCU 11201.

The light source device 11203 includes a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing a surgical site or the like.

The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) by the endoscope 11100.

The treatment instrument control device 11205 controls the drive of the energy treatment instrument 11112 for tissue ablation, incision, blood vessel sealing, or the like. In order to inflate the body cavity of the patient 11132 for the purpose of securing the field of view by the endoscope 11100 and securing the operator's work space, the pneumoperitoneum device 11206 passes gas into the body cavity via the pneumoperitoneum tube 11111. Send in. The recorder 11207 is an apparatus capable of recording various types of information related to surgery. The printer 11208 is a device that can print various types of information related to surgery in various formats such as text, images, or graphs.

In addition, the light source device 11203 that supplies the irradiation light when the surgical site is imaged to the endoscope 11100 can be configured by, for example, a white light source configured by an LED, a laser light source, or a combination thereof. When a white light source is configured by a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high accuracy. Therefore, the light source device 11203 adjusts the white balance of the captured image. It can be carried out. In this case, laser light from each of the RGB laser light sources is irradiated on the observation target in a time-sharing manner, and the drive of the image sensor of the camera head 11102 is controlled in synchronization with the irradiation timing, thereby corresponding to each RGB. It is also possible to take the images that have been taken in time division. According to this method, a color image can be obtained without providing a color filter in the image sensor.

Further, the driving of the light source device 11203 may be controlled so as to change the intensity of the output light every predetermined time. Synchronously with the timing of changing the intensity of the light, the drive of the image sensor of the camera head 11102 is controlled to acquire an image in a time-sharing manner, and the image is synthesized, so that high dynamic without so-called blackout and overexposure A range image can be generated.

Further, the light source device 11203 may be configured to be able to supply light of a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in body tissue, the surface of the mucous membrane is irradiated by irradiating light in a narrow band compared to irradiation light (ie, white light) during normal observation. A so-called narrow-band light observation (Narrow Band Imaging) is performed in which a predetermined tissue such as a blood vessel is imaged with high contrast. Alternatively, in special light observation, fluorescence observation may be performed in which an image is obtained by fluorescence generated by irradiating excitation light. In fluorescence observation, the body tissue is irradiated with excitation light to observe fluorescence from the body tissue (autofluorescence observation), or a reagent such as indocyanine green (ICG) is locally administered to the body tissue and applied to the body tissue. It is possible to obtain a fluorescence image by irradiating excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 can be configured to be able to supply narrowband light and / or excitation light corresponding to such special light observation.

FIG. 14 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in FIG.

The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so that they can communicate with each other.

The lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101. Observation light taken from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

The imaging device constituting the imaging unit 11402 may be one (so-called single plate type) or plural (so-called multi-plate type). In the case where the imaging unit 11402 is configured as a multi-plate type, for example, image signals corresponding to RGB may be generated by each imaging element, and a color image may be obtained by combining them. Alternatively, the imaging unit 11402 may be configured to include a pair of imaging elements for acquiring right-eye and left-eye image signals corresponding to 3D (dimensional) display. By performing the 3D display, the operator 11131 can more accurately grasp the depth of the living tissue in the surgical site. Note that in the case where the imaging unit 11402 is configured as a multi-plate type, a plurality of lens units 11401 can be provided corresponding to each imaging element.

Further, the imaging unit 11402 is not necessarily provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101 immediately after the objective lens.

The driving unit 11403 is configured by an actuator, and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. Thereby, the magnification and the focus of the image captured by the imaging unit 11402 can be adjusted as appropriate.

The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

Further, the communication unit 11404 receives a control signal for controlling driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes, for example, information for designating the frame rate of the captured image, information for designating the exposure value at the time of imaging, and / or information for designating the magnification and focus of the captured image. Contains information about the condition.

Note that the imaging conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. Good. In the latter case, a so-called AE (Auto-Exposure) function, AF (Auto-Focus) function, and AWB (Auto-White Balance) function are mounted on the endoscope 11100.

The camera head control unit 11405 controls driving of the camera head 11102 based on a control signal from the CCU 11201 received via the communication unit 11404.

The communication unit 11411 is configured by a communication device for transmitting and receiving various types of information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

Further, the communication unit 11411 transmits a control signal for controlling driving of the camera head 11102 to the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

The image processing unit 11412 performs various types of image processing on the image signal that is RAW data transmitted from the camera head 11102.

The control unit 11413 performs various types of control related to imaging of the surgical site by the endoscope 11100 and display of a captured image obtained by imaging of the surgical site. For example, the control unit 11413 generates a control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 causes the display device 11202 to display a picked-up image showing the surgical part or the like based on the image signal subjected to the image processing by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 detects surgical tools such as forceps, specific biological parts, bleeding, mist when using the energy treatment tool 11112, and the like by detecting the shape and color of the edge of the object included in the captured image. Can be recognized. When displaying the captured image on the display device 11202, the control unit 11413 may display various types of surgery support information superimposed on the image of the surgical unit using the recognition result. Surgery support information is displayed in a superimposed manner and presented to the operator 11131, thereby reducing the burden on the operator 11131 and allowing the operator 11131 to proceed with surgery reliably.

The transmission cable 11400 for connecting the camera head 11102 and the CCU 11201 is an electric signal cable corresponding to electric signal communication, an optical fiber corresponding to optical communication, or a composite cable thereof.

Here, in the illustrated example, communication is performed by wire using the transmission cable 11400. However, communication between the camera head 11102 and the CCU 11201 may be performed wirelessly.

In the foregoing, an example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described. The technology according to the present disclosure can be applied to the imaging unit 11402 among the configurations described above. By applying the technique according to the present disclosure to the imaging unit 11402, the detection accuracy is improved.

Note that although an endoscopic surgery system has been described here as an example, the technology according to the present disclosure may be applied to, for example, a microscope surgery system and the like.

<Application examples to mobile objects>
The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be any type of movement such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, a construction machine, and an agricultural machine (tractor). You may implement | achieve as an apparatus mounted in a body.

FIG. 15 is a block diagram illustrating a schematic configuration example of a vehicle control system that is an example of a mobile control system to which the technology according to the present disclosure can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example illustrated in FIG. 15, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, a vehicle exterior information detection unit 12030, a vehicle interior information detection unit 12040, and an integrated control unit 12050. Further, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio image output unit 12052, and an in-vehicle network I / F (interface) 12053 are illustrated.

The drive system control unit 12010 controls the operation of the device related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 includes a driving force generator for generating a driving force of a vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism that adjusts and a braking device that generates a braking force of the vehicle.

The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as a headlamp, a back lamp, a brake lamp, a blinker, or a fog lamp. In this case, the body control unit 12020 can be input with radio waves transmitted from a portable device that substitutes for a key or signals from various switches. The body system control unit 12020 receives input of these radio waves or signals, and controls a door lock device, a power window device, a lamp, and the like of the vehicle.

The vehicle outside information detection unit 12030 detects information outside the vehicle on which the vehicle control system 12000 is mounted. For example, the imaging unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The vehicle outside information detection unit 12030 may perform an object detection process or a distance detection process such as a person, a car, an obstacle, a sign, or a character on a road surface based on the received image.

The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of received light. The imaging unit 12031 can output an electrical signal as an image, or can output it as distance measurement information. Further, the light received by the imaging unit 12031 may be visible light or invisible light such as infrared rays.

The vehicle interior information detection unit 12040 detects vehicle interior information. For example, a driver state detection unit 12041 that detects a driver's state is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that images the driver, and the vehicle interior information detection unit 12040 determines the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041. It may be calculated or it may be determined whether the driver is asleep.

The microcomputer 12051 calculates a control target value of the driving force generator, the steering mechanism, or the braking device based on the information inside / outside the vehicle acquired by the vehicle outside information detection unit 12030 or the vehicle interior information detection unit 12040, and the drive system control unit A control command can be output to 12010. For example, the microcomputer 12051 realizes ADAS (Advanced Driver Assistance System) functions including vehicle collision avoidance or impact mitigation, following traveling based on inter-vehicle distance, vehicle speed maintenance traveling, vehicle collision warning, or vehicle lane departure warning. It is possible to perform cooperative control for the purpose.

Further, the microcomputer 12051 controls the driving force generator, the steering mechanism, the braking device, and the like based on the information around the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040. It is possible to perform cooperative control for the purpose of automatic driving that autonomously travels without depending on the operation.

Further, the microcomputer 12051 can output a control command to the body system control unit 12020 based on information outside the vehicle acquired by the vehicle outside information detection unit 12030. For example, the microcomputer 12051 controls the headlamp according to the position of the preceding vehicle or the oncoming vehicle detected by the outside information detection unit 12030, and performs cooperative control for the purpose of anti-glare, such as switching from a high beam to a low beam. It can be carried out.

The sound image output unit 12052 transmits an output signal of at least one of sound and image to an output device capable of visually or audibly notifying information to a vehicle occupant or the outside of the vehicle. In the example of FIG. 13, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are illustrated as output devices. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

FIG. 16 is a diagram illustrating an example of an installation position of the imaging unit 12031.

In FIG. 16, the imaging unit 12031 includes

imaging units

12101, 12102, 12103, 12104, and 12105.

The

imaging units

12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as a front nose, a side mirror, a rear bumper, a back door, and an upper part of a windshield in the vehicle interior of the vehicle 12100. The imaging unit 12101 provided in the front nose and the imaging unit 12105 provided in the upper part of the windshield in the vehicle interior mainly acquire an image in front of the vehicle 12100. The

imaging units

12102 and 12103 provided in the side mirror mainly acquire an image of the side of the vehicle 12100. The imaging unit 12104 provided in the rear bumper or the back door mainly acquires an image behind the vehicle 12100. The imaging unit 12105 provided on the upper part of the windshield in the passenger compartment is mainly used for detecting a preceding vehicle or a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

FIG. 16 shows an example of the shooting range of the imaging units 12101 to 12104. The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided in the front nose, the imaging ranges 12112 and 12113 indicate the imaging ranges of the

imaging units

12102 and 12103 provided in the side mirrors, respectively, and the imaging range 12114 The imaging range of the imaging part 12104 provided in the rear bumper or the back door is shown. For example, by superimposing the image data captured by the imaging units 12101 to 12104, an overhead image when the vehicle 12100 is viewed from above is obtained.

At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

For example, the microcomputer 12051, based on the distance information obtained from the imaging units 12101 to 12104, the distance to each three-dimensional object in the imaging range 12111 to 12114 and the temporal change in this distance (relative speed with respect to the vehicle 12100). In particular, it is possible to extract, as a preceding vehicle, a three-dimensional object that travels at a predetermined speed (for example, 0 km / h or more) in the same direction as the vehicle 12100, particularly the closest three-dimensional object on the traveling path of the vehicle 12100. it can. Further, the microcomputer 12051 can set an inter-vehicle distance to be secured in advance before the preceding vehicle, and can perform automatic brake control (including follow-up stop control), automatic acceleration control (including follow-up start control), and the like. Thus, cooperative control for the purpose of autonomous driving or the like autonomously traveling without depending on the operation of the driver can be performed.

For example, the microcomputer 12051 converts the three-dimensional object data related to the three-dimensional object to other three-dimensional objects such as a two-wheeled vehicle, a normal vehicle, a large vehicle, a pedestrian, and a utility pole based on the distance information obtained from the imaging units 12101 to 12104. It can be classified and extracted and used for automatic avoidance of obstacles. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 determines the collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or higher than the set value and there is a possibility of collision, the microcomputer 12051 is connected via the audio speaker 12061 or the display unit 12062. By outputting an alarm to the driver and performing forced deceleration or avoidance steering via the drive system control unit 12010, driving assistance for collision avoidance can be performed.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether a pedestrian is present in the captured images of the imaging units 12101 to 12104. Such pedestrian recognition is, for example, whether or not the user is a pedestrian by performing a pattern matching process on a sequence of feature points indicating the outline of an object and a procedure for extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras. It is carried out by the procedure for determining. When the microcomputer 12051 determines that there is a pedestrian in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio image output unit 12052 has a rectangular contour line for emphasizing the recognized pedestrian. The display unit 12062 is controlled so as to be superimposed and displayed. Moreover, the audio | voice image output part 12052 may control the display part 12062 so that the icon etc. which show a pedestrian may be displayed on a desired position.

Heretofore, an example of a vehicle control system to which the technology according to the present disclosure can be applied has been described. The technology according to the present disclosure can be applied to the imaging unit 12031 among the configurations described above. Specifically, the

imaging devices

1 and 2 in FIGS. 1 and 10 can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, it is possible to obtain a captured image that is easier to see, and thus it is possible to reduce driver fatigue.

As described above, the embodiments and modifications have been described, but the present disclosure is not limited to the above-described embodiments and the like, and various modifications are possible. For example, the structure of the semiconductor device described in the above embodiment is merely an example, and another layer may be provided. Moreover, the material and thickness of each layer are examples, and are not limited to those described above.

Further, in the above-described embodiment and the like, the backside illumination

type imaging devices

1 and 2 have been described as examples, but the present technology can also be applied to a front side illumination type imaging device. Furthermore, the present technology can also be applied to an imaging device having a stacked structure of two semiconductor chips or four or more semiconductor chips.

In the above embodiment, the example in which the light shielding film 33 is embedded in the pixel separation groove 11A has been described. However, the light shielding film 33 may not be embedded in the pixel separation groove 11A.

In the above-described embodiment and the like, the case where an insulating oxide film containing water or heavy water is provided on both surfaces (for example, the light receiving surface S1 and the surface S2) of the semiconductor substrate has been described. The insulating oxide film to be included may be provided on only one of the surfaces.

The effects described in the above embodiments and the like are merely examples, and other effects may be included or further effects may be included.

The present disclosure may be configured as follows.
(1)
A semiconductor substrate having a light receiving surface and provided with a photoelectric conversion unit;
A wiring layer provided facing the semiconductor substrate and including a wiring and an insulating first oxide film;
The imaging device in which the first oxide film contains heavy water.
(2)
The imaging device according to (1), wherein the wiring layer is provided on a surface opposite to the light receiving surface of the semiconductor substrate.
(3)
The imaging device according to (1) or (2), wherein the semiconductor substrate has a groove provided at a predetermined depth from the light receiving surface.
(4)
Furthermore, an insulating second oxide film provided on the light receiving surface of the semiconductor substrate,
The imaging device according to (3), wherein the second oxide film includes heavy water.
(5)
The imaging device according to (4), wherein the second oxide film is provided in a selective region near the groove.
(6)
The imaging device according to any one of (1) to (5), wherein the first oxide film includes silicon (Si).
(7)
The imaging device according to any one of (1) to (6), wherein the semiconductor substrate is a silicon substrate.
(8)
A first semiconductor chip including the semiconductor substrate and the wiring layer;
The imaging device according to any one of (1) to (7), further including a second semiconductor chip that is stacked on the first semiconductor chip and electrically connected to the first semiconductor chip.
(9)
The imaging apparatus according to (8), further including a through electrode structure that electrically connects the first semiconductor chip and the second semiconductor chip.
(10)
A semiconductor substrate having a light receiving surface and provided with a photoelectric conversion unit;
A wiring layer provided facing the semiconductor substrate and including a wiring and an insulating first oxide film;
An imaging apparatus in which the first oxide film includes an OH group having a concentration of 2 × 10 ²⁰ cm ³ or more.
(11)
Forming a photoelectric conversion part on a semiconductor substrate;
Forming a wiring layer including a wiring and an insulating first oxide film on the semiconductor substrate;
Water or heavy water is contained in the first oxide film;
A method for manufacturing an imaging device, wherein the first oxide film containing water or heavy water is subjected to a heat treatment.
(12)
The manufacturing method of the imaging device according to (11), wherein the semiconductor substrate and the wiring layer are immersed in water or heavy water so that the first oxide film contains water or heavy water.
(13)
The manufacturing method of the imaging device according to (11), wherein the semiconductor substrate and the wiring layer are exposed to a water atmosphere or a heavy water atmosphere so that the first oxide film contains water or heavy water.
(14)
The method for manufacturing an imaging device according to any one of (11) to (13), wherein the heat treatment is performed at 300 ° C. or higher.

This application claims priority on the basis of Japanese Patent Application No. 2018-48839 filed on March 16, 2018 at the Japan Patent Office. The entire contents of this application are incorporated herein by reference. This is incorporated into the application.

Those skilled in the art will envision various modifications, combinations, subcombinations, and changes, depending on design requirements and other factors, which are within the scope of the appended claims and their equivalents. It is understood that

Claims

A semiconductor substrate having a light receiving surface and provided with a photoelectric conversion unit;
A wiring layer provided facing the semiconductor substrate and including a wiring and an insulating first oxide film;
The imaging device in which the first oxide film contains heavy water.
The imaging device according to claim 1, wherein the wiring layer is provided on a surface opposite to the light receiving surface of the semiconductor substrate.
The imaging device according to claim 1, wherein the semiconductor substrate has a groove provided at a predetermined depth from the light receiving surface.
Furthermore, an insulating second oxide film provided on the light receiving surface of the semiconductor substrate,
The imaging device according to claim 3, wherein the second oxide film contains heavy water.
The imaging device according to claim 4, wherein the second oxide film is provided in a selective region near the groove.
The imaging device according to claim 1, wherein the first oxide film includes silicon (Si).
The imaging device according to claim 1, wherein the semiconductor substrate is a silicon substrate.
A first semiconductor chip including the semiconductor substrate and the wiring layer;
The imaging device according to claim 1, further comprising: a second semiconductor chip that is stacked on the first semiconductor chip and electrically connected to the first semiconductor chip.
The imaging apparatus according to claim 8, further comprising a through electrode structure that electrically connects the first semiconductor chip and the second semiconductor chip.
A semiconductor substrate having a light receiving surface and provided with a photoelectric conversion unit;
A wiring layer provided facing the semiconductor substrate and including a wiring and an insulating first oxide film;
An imaging apparatus in which the first oxide film includes an OH group having a concentration of 2 × 10 20 cm 3 or more.
Forming a photoelectric conversion part on a semiconductor substrate;
Forming a wiring layer including a wiring and an insulating first oxide film on the semiconductor substrate;
Water or heavy water is contained in the first oxide film;
A method for manufacturing an imaging device, wherein the first oxide film containing water or heavy water is subjected to a heat treatment.
The manufacturing method of the imaging device according to claim 11, wherein the first oxide film includes water or heavy water by immersing the semiconductor substrate and the wiring layer in water or heavy water.
The manufacturing method of the imaging device according to claim 11, wherein the first oxide film contains water or heavy water by exposing the semiconductor substrate and the wiring layer to a water atmosphere or a heavy water atmosphere.
The manufacturing method of the imaging device according to claim 11, wherein the heat treatment is performed at 300 ° C. or higher.