Imaging device

Abstract

To reduce the noise of an imaging device.SOLUTION: An imaging device includes a substrate, a photodiode semiconductor layer on the substrate, an upper electrode and a lower electrode having the photodiode semiconductor layer held therebetween, and a light-blocking wire upper than the upper electrode when the substrate is regarded as a lowermost layer. The photodiode semiconductor layer includes a first semiconductor layer, and a second semiconductor between the first semiconductor layer and the lower electrode. The photodiode semiconductor layer includes a concave part excluding the first semiconductor layer in a region covered with the light-blocking wire in a plan view. In a region overlapping with the concave part in the plan view, the upper electrode is excluded. In the region overlapping with the concave part in the plan view, a part of the second semiconductor layer and a part of the lower electrode exist.SELECTED DRAWING: Figure 3B

Description

[Technical field]

[0001] The present disclosure relates to an imaging device. [Background technology]

[0002] For example, in an image sensor equipped with a photodiode having a PN junction or PIN junction, a negative voltage is applied to the P side and a positive voltage is applied to the N side to maintain a reverse bias state, effectively drifting the charge generated from the incident light. The drifted charge is read out as an electrical signal by a detection circuit. By arranging this image sensor one-dimensionally or two-dimensionally, it can be used as an image sensor that outputs an image from an optical signal.

[0003] Such an imaging device is used, for example, as a Flat Panel Detector (FPD) for an X-ray sensor. FPDs used in X-ray sensors are generally classified into direct conversion type and indirect conversion type. Direct conversion type FPDs use a photoelectric conversion element that directly converts X-rays into an electrical signal using amorphous selenium, CdTe, or the like. Indirect conversion type FPDs use a phosphor (scintillator) in the X-ray detection panel that converts X-rays into light, such as visible light or ultraviolet light, and a photodiode array that converts light into an electrical signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 11024665 Summary of the Invention [Problem to be solved by the invention]

[0005] The signal-to-noise ratio (SN ratio) is used as an index of the sensitivity characteristics of an image sensor or an image sensor-based imaging device. To achieve a high S / N ratio, high sensitivity and reduced noise are required. [Means for solving the problem]

[0006] An imaging device according to an embodiment of the present disclosure includes a substrate, a photodiode semiconductor layer on the substrate, an upper electrode and a lower electrode sandwiching the photodiode semiconductor layer, and a light-shielding wiring layer above the upper electrode, with the substrate being the lowest layer. The photodiode semiconductor layer includes a first semiconductor layer and a second semiconductor layer between the first semiconductor layer and the lower electrode. The photodiode semiconductor layer includes a recess in a region covered by the light-shielding wiring in a plan view, where the first semiconductor layer is removed. The upper electrode is removed from a region overlapping with the recess in the plan view. A part of the second semiconductor layer and a part of the lower electrode are present in the region overlapping with the recess in the plan view. Effect of the Invention

[0007] According to one aspect of the present disclosure, noise in an imaging device can be improved. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a configuration of an image sensor according to an embodiment; [Diagram 2] 2 is a circuit diagram showing an equivalent circuit of a pixel of the image sensor according to the embodiment; [Figure 3A] FIG. 2 is a plan view showing a schematic structure including pixels, gate lines, data lines, and bias lines. [Figure 3B] 3B is a cross-sectional view taken along line IIIB-IIIB' in FIG. 3A. [Figure 3C] FIG. 13 is another plan view showing a schematic example of a structure including pixels, gate lines, data lines, and bias lines. [Figure 3D] FIG. 3D is a cross-sectional view taken along line IIID-IIID′ in FIG. 3C. [Figure 4A] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 4B] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 4C] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 4D] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 4E] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 4F] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 4G] 2A to 2C are schematic diagrams illustrating a laminated structure on an insulating substrate during a manufacturing process. [Figure 5A] FIG. 13 is a plan view showing a schematic diagram of another example structure including pixels, gate lines, data lines, and bias lines. [Figure 5B] 5B is a cross-sectional view taken along line VB-VB' in FIG. 5A. [Figure 6] FIG. 13 is a plan view showing a schematic diagram of another example structure including pixels, gate lines, data lines, and bias lines. [Figure 7] FIG. 2 is a cross-sectional view of a region including a pixel. [Figure 8] FIG. 2 is a cross-sectional view of a region including a pixel. [Figure 9A] FIG. 13 is a plan view showing a schematic diagram of another example structure including pixels, gate lines, data lines, and bias lines. [Figure 9B] 9B is a cross-sectional view taken along line IXB-IXB' in FIG. 9A. [Figure 10A] FIG. 13 is a plan view showing a schematic diagram of another example structure including pixels, gate lines, data lines, and bias lines. [Figure 10B] 10B is a cross-sectional view taken along line XB-XB' in FIG. 10A. [Figure 11A] FIG. 13 is a plan view showing a schematic diagram of another example structure including pixels, gate lines, data lines, and bias lines. [Figure 11B] 11B is a cross-sectional view taken along line XIB-XIB' in FIG. 11A. [Figure 12] FIG. 13 is a plan view showing a schematic diagram of another example structure including pixels, gate lines, data lines, and bias lines. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The size and scale of each component in each drawing are appropriately changed to ensure the visibility of the drawing. Hatching in each drawing is for distinguishing each component and does not necessarily mean a cut surface. In addition, the term "transistor" is used to refer to a nonlinear element used as a switching element or an amplifying element, but the transistor includes a thin film transistor (TFT).

[0010] An embodiment of the present specification is an imaging element. The imaging element of the present disclosure can be used in, for example, an imaging device, and can be used in a radiography device in the medical and industrial non-destructive testing fields. The light detected by the imaging element is an electromagnetic wave having any frequency, and can include X-rays as well as infrared light and visible light.

[0011] For example, in an image sensor equipped with a photodiode having a PN junction or PIN junction, the charge generated from the incident light is effectively drifted by holding the device in a reverse bias state, with a negative voltage applied to the P side and a positive voltage applied to the N side. In order to hold the device in a reverse bias state, separate potentials must be applied to the P side and N side, which requires electrodes or wiring for each.

[0012] Either the P side or the N side of the photodiode becomes the window layer through which light enters. However, if the photodiode is covered by a wiring layer or the like during the reverse bias period, it will be in shadow and will not contribute to photoelectric conversion.

[0013] The signal-to-noise ratio is used as an index of the sensitivity characteristics of an image sensor. To achieve a high signal-to-noise ratio, high sensitivity and reduced noise are required. A junction capacitance exists between the P and N layers according to their area, and when held in a reverse bias state, kTC noise proportional to the capacitance occurs, reducing image quality. This junction capacitance and kTC noise are independent of whether the area is covered by a wiring layer. Therefore, compared to other areas, the area covered by the wiring layer is considered to be more adversely affected by noise than the benefits it provides as an image sensor.

[0014] In one embodiment of the present specification, in the region where wiring is bridged in the semiconductor layer of a photodiode, for example, made of a PN layer or a PIN layer, an upper impurity-doped semiconductor layer (for example, a p-aSi layer) is partially etched and removed to release the junction state. The kTC noise is reduced in proportion to the area of ​​the region where the junction state is removed, and image quality is improved. In addition, step breaks in the wiring layer straddling the photodiode semiconductor layer are prevented, improving yield.

[0015] The kTC noise is proportional to the pixel capacitance, most of which is caused by the junction capacitance of the photodiode.The junction capacitance is proportional to the area of ​​the opposing P and N layers, so by removing the upper layer by etching, the junction capacitance is reduced, and the kTC noise is also reduced.

[0016] Since the electric field generated by the opposing P and N layers causes the charges generated by light to drift, etching the light-receiving area would impair the original effect of the image sensor. Therefore, by releasing the junction in the areas that are covered and shaded by the wiring, the decrease in photoelectric conversion efficiency is suppressed.

[0017] In addition, photodiodes are generally formed thickly to effectively absorb light, but this increases the step height of the lower layer, making the upper layer wiring prone to step disconnections. Therefore, by partially removing only the upper layer side of the photodiode semiconductor layer, steps are formed for the wiring, reducing the drop at the step. This improves step coverage and reduces the frequency of step disconnections.

[0018] A typical material used for the photodiode semiconductor layer is amorphous silicon, but the features of this embodiment can also be applied to photodiodes using semiconductor materials other than amorphous silicon.

[0019] In this specification, a photodiode semiconductor layer consisting of a PN layer or a PIN layer is described as one embodiment, but the photodiode semiconductor layer can also be applied to a Schottky photodiode semiconductor layer that can be expressed as a PI layer or an IN layer, or an avalanche photodiode semiconductor layer formed by stacking four or more layers of any of P, I, and N layers.

[0020] <Embodiment 1> [Image sensor configuration] 1 is a block diagram showing an example of the configuration of an image sensor, which is an imaging device according to an embodiment of the present specification. The image sensor 10 includes a sensor substrate 11 and a control circuit. The control circuit includes a drive circuit 14, a signal detection circuit 16, and a main control circuit 18.

[0021] The sensor substrate 11 includes an insulating substrate (e.g., a glass substrate) and a detection region 12 in which pixels 13 are arranged in a matrix on the insulating substrate. The pixels 13 are elements on the substrate, including photodiodes that serve as photodetectors. The layout of the pixels 13 is not limited to the matrix layout shown in Fig. 1, and may be, for example, a line layout consisting of a row of pixels 13. In the example of an X-ray image sensor, a scintillator that receives radiation, which is the detection light, and emits fluorescence is disposed in the detection region 12.

[0022] The pixels 13 are disposed at each intersection of a plurality of data lines 106 extending vertically and arranged horizontally in Fig. 1 and a plurality of gate lines (scanning lines) 105 extending horizontally and arranged vertically in Fig. 1. The pixels 13 are each connected to a bias line 107 extending vertically and arranged horizontally in Fig. 1. In Fig. 1, only one pixel, one data line, one gate line and one bias line are indicated by the reference characters 13, 106, 105 and 107, respectively.

[0023] Each of the data lines 106 is connected to a different pixel column. Each of the gate lines 105 is connected to a different pixel row. The data lines 106 are connected to a signal detection circuit 16, and the gate lines are connected to a drive circuit 14. The bias line 107 is connected to a common bias line 108. A bias potential is applied to a pad 109 of the common bias line 108. The drive circuit 14 drives the gate lines 105 of the pixels 13 for light detection by the pixels 13. The signal detection circuit 16 detects signals from each of the data lines. A main control circuit 18 controls the drive circuit 14 and the signal detection circuit 16.

[0024] [Pixel circuit configuration] 2 is a circuit diagram showing an equivalent circuit of one pixel 13. The pixel 13 includes a photodiode 121 which is a photoelectric conversion element, and a thin film transistor (TFT) 122 which is a switching element. A gate terminal of the thin film transistor 122 is connected to the gate line 105, a drain terminal is connected to the data line 106, and a source terminal is connected to the cathode terminal of the photodiode 121. In the example of FIG. 2, an anode terminal of the photodiode 121 is connected to a bias line 107.

[0025] The thin film transistor 122 is, for example, an oxide semiconductor thin film transistor. Examples of oxide semiconductors include IGZO (InGaZnO) and ZnO. In one embodiment of the present specification, the thin film transistor 122 has an N-type conductivity.

[0026] The pixel 13 further includes a junction capacitance (not shown) of the photodiode 121. In terms of the circuit, the junction capacitance is connected in parallel to the photodiode 121, to the thin film transistor 122 and the bias line 107. The image sensor 10 used as an X-ray imaging device accumulates a signal charge corresponding to the amount of light irradiated on the photodiode 121 in a capacitance component of the pixel 13.

[0027] The main control circuit 18 makes the thin film transistor 122 arranged in the pixel 13 conductive, and extracts the charge accumulated in the capacitance component of the pixel 13 to the outside, thereby reading out the signal. Specifically, the drive circuit 14 sequentially selects the gate lines 105 and applies a pulse that makes the thin film transistor 122 conductive. The anode terminal of the photodiode 121 is connected to the bias line 107, and a reference potential is applied to the data line 106 by the signal detection circuit 16. Therefore, the photodiode 121 is charged with a difference voltage between the bias potential of the bias line 107 and the reference potential. In general, this difference voltage is set to a reverse bias voltage in which the cathode potential is higher than the anode potential.

[0028] The charge required to recharge the photodiode 121 to this reverse bias voltage depends on the amount of light irradiated on the photodiode 121. The signal detection circuit 16 reads out the signal charge by integrating the current that flows when the photodiode 121 is recharged to the reverse bias.

[0029] In reading out the signal charge, the voltage of the terminal of the thin film transistor 122 connected to the data line 106 is equal to or higher than the voltage of the terminal connected to the photodiode 121. In detecting the signal charge, the terminal of the thin film transistor 122 connected to the data line 106 is the drain, and the terminal connected to the photodiode 121 is the source. Note that the pixel 13 may include additional components (not shown) in addition to the components shown in FIG. 2, such as an additional thin film transistor.

[0030] [Pixel structure example] Below, we will explain some examples of the device structure of the pixel 13. Fig. 3A is a plan view that shows a schematic example of a structure including the pixel 13, the gate line 105, the data line 106, and the bias line 107. In Fig. 3A, the data line 106 extends in the vertical direction (Y direction), the gate line 105 extends in the horizontal direction (X direction), and a thin film transistor 122 is disposed at the intersection between them.

[0031] 3A, the entire area of ​​the upper electrode 305 overlaps with the lower electrode 301 in a plan view (in the stacking direction). That is, the entire area of ​​the upper electrode 305 is included within the area of ​​the lower electrode 301 in a plan view.

[0032] The photodiode 121 includes a photodiode semiconductor layer made of, for example, a PN layer or a PIN layer, and an upper electrode and a lower electrode sandwiching the photodiode semiconductor layer. In the configuration example of FIG. 3A, the outer diameters of the upper electrode 305 and the amorphous silicon layer of the photodiode 121 in a plan view may be the same, or the outer shapes of the upper electrode 305 and the semiconductor layer in a plan view may not be the same, for example, the area of ​​the upper electrode 305 may be small. The portion of the lower electrode 301 that contacts the photodiode semiconductor layer constitutes the lower electrode of the photodiode 121.

[0033] The pixel 13 includes a thin film transistor 122 and a bias line 107. The thin film transistor 122 includes a gate electrode 251, an island-shaped semiconductor portion 252, a source electrode 253, and a drain electrode 254.

[0034] The bias line 107 extends in the vertical direction (Y direction) in Fig. 3A. The bias line 107 is in a layer above the upper electrode 305, and is connected to each of the upper electrodes 305 of the multiple pixels 13 via contact parts 323. The bias line 107 passes over the upper electrode 305 from one end of the upper electrode 305 to the opposite end. The bias line 107 transmits a bias potential and applies the bias potential to the upper electrode 305 of the photodiode 121.

[0035] In the configuration example of Fig. 3A, the lower electrode 301 and the upper electrode 305 do not overlap the gate line 105 and the data line 106 in a plan view, and are separated therefrom. The lower electrode 301 and the upper electrode 305 also do not overlap the semiconductor portion 252 in a plan view, and are separated therefrom. Note that Fig. 3A shows an example of a pixel structure, and the pixel 13 may have other structures.

[0036] Fig. 3B shows a cross-sectional view taken along line IIIB-IIIB' in Fig. 3A. In the following description, reference numerals of some elements may be omitted in the drawings. Referring to Fig. 3B, the thin film transistor 122 includes a gate electrode 251 formed on an insulating substrate 271, a gate insulating layer 272 on the gate electrode 251, and a semiconductor portion 252 on the gate insulating layer 272. The relationship between the two layers is such that the layer closer to the substrate 271 is called the lower layer, and the layer farther from the substrate 271 is called the upper layer.

[0037] 3A, the gate electrode 251 protrudes upward from the gate line 105 extending in the lateral direction (X direction). The gate electrode 251 and the gate line 105 are formed on an insulating substrate (insulating layer) 271, and are included in the same conductor layer. Note that a silicon insulating layer may be present between the insulating substrate 271 and the gate electrode 251 and the gate line 105.

[0038] Continuous or separated conductor parts included in the same conductor layer are made of the same material on the same insulating layer and in direct contact with the insulating layer. In manufacturing, the conductor parts of the same conductor layer are formed in the same process. The conductor layer may have a single layer structure or a multilayer structure.

[0039] In this configuration example, the thin film transistor 122 has a bottom gate structure, and the gate electrode 251 is present below the semiconductor portion 252. The thin film transistor 122 further includes a source electrode 253 and a drain electrode 254 on a gate insulating layer 272. The source electrode 253 and the drain electrode 254 are included in the same conductor layer. The thin film transistor may have a top gate structure.

[0040] According to the flow of carriers in detecting electric charge of the photodiode 121, the electrode 253 becomes a source electrode, and the electrode 254 becomes a drain electrode. The source electrode 253 and the drain electrode 254 each overlap with the semiconductor portion 252 of the conductor film in a planar view. The source electrode 253 and the drain electrode 254 each directly contact the semiconductor portion 252. The source electrode 253 and the drain electrode 254 are formed so as to contact the side surface and part of the upper surface of the island-shaped semiconductor portion 252.

[0041] The gate insulating layer 272 is formed so as to cover the entire surface of the gate electrode 251. The gate insulating layer 272 is formed between the gate electrode 251 and the semiconductor portion 252. The first interlayer insulating layer 273 covers the entire thin film transistor 122. Specifically, the first interlayer insulating layer 273 covers the upper surface of the semiconductor portion 252, and the upper surfaces of the source electrode 253 and the drain electrode 254.

[0042] The substrate 271 is formed of, for example, glass or resin. The gate electrode 251 is a conductor and can be formed of a metal such as Al, Mo, Cr, Ti, Cu, or an alloy or a laminate of these. The gate insulating layer 272 can be formed of, for example, an insulating material represented by SiNxOy (x and y include 0) or an insulating material such as Al2O3, or a laminate of these.

[0043] The semiconductor constituting the semiconductor portion 252 is, for example, an oxide semiconductor. The oxide semiconductor includes, for example, at least one of In, Ga, and Zn, and examples thereof include amorphous InGaZnO (a-InGaZnO) and microcrystalline InGaZnO. The semiconductor may be, for example, amorphous silicon or polysilicon.

[0044] The source electrode 253 and the drain electrode 254 are conductors and can be formed of, for example, a metal such as Al, Mo, Cr, Ti, or Cu, an alloy thereof, or a laminate thereof. The first interlayer insulating layer 273 is an inorganic or organic insulator. The first interlayer insulating layer 273 may be composed of, for example, an insulating material represented by SiNxOy (x and y include 0) or an insulating material such as Al2O3, or may be a laminate thereof.

[0045] The lower electrode 301 is connected to a conductive film including the source electrode 253 of the thin film transistor 122 through a contact portion 227 in a via hole of the first interlayer insulating layer 273. The lower electrode 301 is a conductor, and can be formed of, for example, a metal such as Al, Mo, Cr, Ti, Cu, an alloy thereof, or a laminate thereof.

[0046] The photodiode 121 is composed of a photoelectric conversion section between the lower electrode 301 and the upper electrode 305, and the lower electrode 301 and the upper electrode 305 that are in contact with the photoelectric conversion section. An example of the photodiode 121 shown in Fig. 3B is a PIN diode. A PIN diode can detect light efficiently by forming a wide depletion layer in the film thickness direction. The upper electrode 305 is an electrode that is transparent to the light from the scintillator, and is, for example, ITO.

[0047] The photoelectric conversion section of the photodiode 121 includes an N-type amorphous silicon layer (film) 202 (second semiconductor layer) on the lower electrode 301, an intrinsic amorphous silicon layer (film) 203 (second or third semiconductor layer) on the N-type amorphous silicon layer 202, and a P-type amorphous silicon layer (film) 204 (first semiconductor layer) on the intrinsic amorphous silicon layer 203. In this example, the photodiode semiconductor layer is composed of three stacked semiconductor layers 202, 203, and 204. The N-type amorphous silicon layer and the P-type amorphous silicon layer are examples of impurity-doped semiconductor layers. The positions of the N-type amorphous silicon layer 202 and the P-type amorphous silicon layer 204 may be reversed.

[0048] The N-type amorphous silicon layer 202 is made of, for example, hydrogenated amorphous silicon doped with phosphorus. The P-type amorphous silicon layer 204 is made of, for example, hydrogenated amorphous silicon doped with boron. The N-type amorphous silicon layer and the P-type amorphous silicon layer may be simply referred to as an N layer and a P layer.

[0049] In this configuration example, the N-type amorphous silicon layer 202 is in direct contact with the lower electrode 301. The upper electrode 305 is formed on the P-type amorphous silicon layer 204. In this configuration example, the upper electrode 205 is in direct contact with the P-type amorphous silicon layer 204. Light to be detected is incident on the photodiode 121 from the upper electrode 305 side. Note that the positions of the N-type amorphous silicon layer 202 and the P-type amorphous silicon layer 204 may be reversed, and the intrinsic amorphous silicon layer 203 may be omitted.

[0050] A second interlayer insulating layer 275 is formed to cover the lower electrode 301, the silicon layers 202-204, and the upper electrode 305. The second interlayer insulating layer 275 is an inorganic or organic insulator. The second interlayer insulating layer 275 may be formed of, for example, SiNxOy (x and y include 0), or an acrylic resin, a phenolic resin, or an epoxy resin, or may be a laminate thereof.

[0051] The bias line 107 and the data line 106 are formed on the second interlayer insulating layer 275. In this example, the bias line 107 and the data line 106 are in direct contact with the second interlayer insulating layer 275. The data line 106 is connected to a conductor film including the drain electrode 254 of the thin film transistor 122 through a contact portion 228 in a via hole of the second interlayer insulating layer 275 and the first interlayer insulating layer 273.

[0052] The bias line 107 is connected to the upper electrode 305 by a contact portion 323 formed in a via hole of the second interlayer insulating layer 275. The bias line 107 and the data line 106 are conductors and can be formed of, for example, a metal such as Al, Mo, Cr, Ti, Cu, or an alloy or a laminate of these. The bias line 107 is light-shielding (non-transparent) to the light with which the photodiode 121 performs photoelectric conversion. The data line 106 may be formed of a transparent material such as ITO. Light-shielding metal materials include various materials having preferable properties, which allows for a wide range of designs.

[0053] A passivation layer 276 is formed so as to cover the data line 106, the bias line 107, and the second interlayer insulating layer 275. The passivation layer 276 covers the entire area of ​​the detection region 12. The passivation layer 276 is an inorganic or organic insulator. The passivation layer 276 may be formed of, for example, SiNxOy (x and y include 0), or an acrylic resin, a phenolic resin, or an epoxy resin, or may be a laminate thereof. A scintillator (not shown) is disposed on the passivation layer 276 .

[0054] A scintillator (not shown) covers the entire detection region 12. The scintillator emits light when excited by radiation. Specifically, the scintillator converts incident X-rays into light of a wavelength that is detected by the photodiode 121. The photodiode 121 generates signal charges in response to the light from the scintillator and accumulates them in the capacitance component of the pixel 13.

[0055] In one embodiment of the present specification, a recess 210A is formed in an upper layer portion of the photodiode semiconductor layer. In the recess 210A, a part of the P-type amorphous silicon layer 204 is removed in a plan view. In the example of FIG. 3B, a part of the intrinsic amorphous silicon layer 203 is also removed in the stacking direction. The intrinsic amorphous silicon layer 203 does not have to be removed. In a plan view, the upper electrode 305 is excluded from the area overlapping with the recess 210A and does not exist. In other words, the recess 210A is formed outside the range covered by the upper electrode 305.

[0056] In the recess 210A, in the stacking direction, the entire upper electrode 305 and the entire P-type amorphous silicon layer 204 are removed, and a part of the intrinsic amorphous silicon layer 203 is removed. The recess 210A extends along the longitudinal direction (Y direction) of the bias line 107, and has two inner side surfaces facing each other in the lateral direction.

[0057] The inner side surface is composed of a stack of the side surface of upper electrode 305, the side surface of P-type amorphous silicon layer 204, and the inner surface of the recess in intrinsic amorphous silicon layer 203. The bottom surface of recess 210A is composed of a part of the upper surface of intrinsic amorphous silicon layer 203. By forming a recess in intrinsic amorphous silicon layer 203, P-type amorphous silicon layer 204 can be reliably removed.

[0058] In other words, in the recess 210A, the side surface of the upper electrode 305 and the side surface of the P-type amorphous silicon layer 204 are exposed. Also, the inner side surface of the recess of the intrinsic amorphous silicon layer 203 and a part of the upper surface of the intrinsic amorphous silicon layer 203 (the bottom surface of the recess) are exposed. The recess 210A is filled with the second interlayer insulating layer 275.

[0059] At least a part of the recess 210A is covered by the bias wire 107 in plan view. In the example shown in FIG. 3B, the left and right ends of the bias wire 107 coincide with the left and right ends (left and right inner walls) of the recess 210A. The width of the recess 210A, that is, the horizontal size in FIG. 3B, may be smaller or larger than the width of the bias wire 107. Also, only one of the left and right ends of the recess 210A and the bias wire 107 may coincide in plan view, and the other may be shifted. In plan view, both the left and right ends of the bias wire 107 may be located inside the recess 210A, or both or only one may be located outside the recess 210A.

[0060] In the example of Fig. 3B, the upper doped silicon layer (P-type amorphous silicon layer 204 in Fig. 3B) is partially removed in the region covered by the bias line 107 of the thick amorphous silicon layer (photodiode semiconductor layer) made of a PIN layer. Most of the kTC noise is caused by the junction capacitance of the photodiode 121. And since the junction capacitance is proportional to the area of ​​the opposing P layer and N layer, removing the layer located on the upper side reduces the junction capacitance and the kTC noise.

[0061] At least a part or the whole of the recess 210A is formed below the non-transparent bias line 107 and is covered by the bias line 107. Therefore, it is possible to suppress a decrease in photoelectric conversion efficiency caused by forming the recess 210A. In the example shown in FIG. 3B, a part of the intrinsic amorphous silicon layer 203 is left in the stacking direction, and the upper surface thereof forms the bottom surface of the recess 210A. This makes it possible to make the recess 210A shallower than a configuration in which the entire intrinsic amorphous silicon layer 203 and even the underlying N-type amorphous silicon layer 202 are removed. The shallow recess 210A can reduce the possibility that a deep recess will increase the drop of the bias line, causing an undesirable effect on the shape of the bias line 107, such as a breakage.

[0062] Fig. 3C is another plan view showing a schematic example of a structure including pixels 13, gate lines 105, data lines 106, and bias lines 107. In Fig. 3C, only the outline of bias line 107 is shown by a dashed line, and recesses 210A and 210B below bias line 107 and intrinsic amorphous silicon layer 203 are drawn through bias line 107. Other parts are similar to Fig. 3A.

[0063] In Fig. 3C, there are two recesses 210A and 210B sandwiching contact portion 323. One of the recesses 210 may be omitted. As described with reference to Fig. 3B, in recesses 210A and 210B, P-type amorphous silicon layer 204 is removed and intrinsic amorphous silicon layer 203 is exposed.

[0064] Each of the recesses 210A and 210B extends in the Y direction in FIG. 3C so as to overlap with the bias line 107. In this example, the width (size in the X direction) of the recesses 210A and 210B matches the width of the bias line 107, and both ends thereof match in a plan view. The Y direction end (upper end in FIG. 3C) of the recess 210B matches the end 215B of the photodiode semiconductor layer. The Y direction end (lower end in FIG. 3C) of the recess 210A matches the upper electrode 305 and the end 215A of the photodiode semiconductor layer of the photodiode 121.

[0065] Thus, the bias line 107 crosses one end (upper side in FIG. 3C) of the N-type amorphous silicon layer 202 in a plan view, and a part of the recess 210A overlaps that end in a plan view. The bias line 107 crosses the other end (lower side in FIG. 3C) of the N-type amorphous silicon layer 202 in a plan view, and a part of the recess 210B overlaps that end in a plan view.

[0066] 3D shows a cross-sectional view taken along line IIID-IIID' in FIG. 3C. The bias line 107 is connected to the upper electrode 305 via a contact portion 323. The two recesses 210A and 210B reach the ends of the photodiode semiconductor layer, that is, the ends 215A and 215B of the remaining N-type amorphous silicon layer 202 and the intrinsic amorphous silicon layer 203, respectively. In FIG. 3D, the upper sides of the left and right ends 215A and 215B of the photodiode semiconductor layer are partially removed, and the left and right ends 215A and 215B are present in the recesses 210A and 210B.

[0067] In FIG. 3D, the thickness of photodiode 121 where recesses 210A and 210B are formed, i.e., thickness D2 of the edge of the photodiode semiconductor layer, is smaller than thickness D1 in the vicinity of contact portion 323 where recesses 210A and 210B are not formed and P-type amorphous silicon layer 204 remains.

[0068] The photodiode semiconductor layer is formed thickly to effectively absorb light. Therefore, at the end of the photodiode semiconductor layer, the step below the bias line 107 that spans the photodiode semiconductor layer becomes high. This makes it easy for the bias line 107 to break. By forming recesses 210A and 210B by partially removing only the upper layer side of the photodiode semiconductor layer, steps are formed for the bias line 107, and the step at the end of the photodiode semiconductor layer becomes smaller. This improves step coverage and reduces the frequency of step breaks in the bias line 107.

[0069] Depending on the design, the intrinsic amorphous silicon layer may be completely removed in the stacking direction in the recess of the photodiode semiconductor layer.

[0070] [Manufacturing method example] An example of a manufacturing method of the sensor substrate 11 (pixel 13) will be described below. FIGS. 4A to 4G are schematic diagrams showing a laminated structure on an insulating substrate 271 in different steps in the manufacturing method. Referring to FIG. 4A, the manufacturing method forms a gate electrode 251 (including a gate line not shown in FIG. 4A) on the insulating substrate 271 by, for example, sputtering and etching, and further forms a gate insulating layer 272 by, for example, CVD (Chemical Vapor Deposition) so as to cover the gate electrode 251 of the insulating substrate 271. Next, a semiconductor portion 252 is formed by, for example, sputtering or CVD and etching, and further forms a source electrode 253 and a drain electrode 254 by, for example, sputtering and etching.

[0071] 4B, in the manufacturing method, a first interlayer insulating layer 273 is formed by, for example, CVD so as to cover the TFT, and a contact hole is formed by etching. Next, a metal layer 401 including a lower electrode 301 is formed by, for example, sputtering. A contact portion 227 fills the hole in the first interlayer insulating layer 273 and directly contacts the source electrode 253.

[0072] 4C, in the manufacturing method, an N-type amorphous silicon layer 402, an intrinsic amorphous silicon layer 403, and a P-type amorphous silicon layer 404 are laminated. The N-type amorphous silicon layer 402 is formed, for example, by forming an amorphous silicon layer by CVD and then doping it with phosphorus. The P-type amorphous silicon layer 404 is formed, for example, by forming an amorphous silicon layer by CVD and then doping it with boron. Parts of these amorphous silicon layers 402, 403, and 404 are included in the photodiode 121.

[0073] Next, in the manufacturing method, the upper electrode 305 is formed by, for example, sputtering and etching on the P-type amorphous silicon layer 404. In order to form the recesses 210A and 210B of the photodiode 121, the upper electrode 305 has openings in the etched away portions.

[0074] Referring to FIG. 4D, the manufacturing method uses the upper electrode 305 as a mask to remove a part of the P-type amorphous silicon layer 404 and a part of the intrinsic amorphous silicon layer 403 by etching. Alternatively, a photoresist (not shown) patterned on the upper layer of the upper electrode 305 may be used as the mask. The removed part of the P-type amorphous silicon layer 404 is completely removed in the stacking direction. The removed part of the intrinsic amorphous silicon layer 403 is a part of the P-type amorphous silicon layer 404 in the stacking direction. In the example shown in FIG. 4D, the width of the upper electrode 305 and the width of the remaining inner surface side of the remaining P-type amorphous silicon layer 404 and the remaining intrinsic amorphous silicon layer 403 are the same, but the widths may not be the same.

[0075] Referring to FIG. 4E, the manufacturing method involves removing unnecessary portions of the intrinsic amorphous silicon layer 403, the N-type amorphous silicon layer 402 and the metal layer 401 by etching using photolithography to form the amorphous silicon layers 202, 203 and 204 of the lower electrode 301 and the photodiode 121.

[0076] Referring to FIG. 4F, the manufacturing method forms the second interlayer insulating layer 275 by, for example, CVD so as to cover the photodiode 121 and the first interlayer insulating layer 273. Referring to FIG. 4G, the manufacturing method forms contact holes in the second interlayer insulating layer 275 by etching, and then forms the bias line 107 and the data line 106 by, for example, sputtering and etching. The data line 106 is connected to the drain electrode 254 via the contact portion 228. The bias line 107 is connected to the upper electrode 305 via the contact portion 323 not shown in FIG. 4G. Next, the manufacturing method forms the passivation layer 276 by, for example, CVD so as to cover the entire detection region 12.

[0077] <Embodiment 2> Another structural example of the detection region 12 will be described. Fig. 5A is a plan view showing a schematic diagram of another structural example including the pixel 13, the gate line 105, the data line 106, and the bias line 107. In Fig. 5A, only the outline of the bias line 107 is shown by a dashed line, and the recesses 210C and 210D below the bias line 107 and the intrinsic amorphous silicon layer 203 are drawn through the bias line 107. In the following, differences from the configuration described with reference to Figs. 3A to 3D will be mainly described.

[0078] The position of the bias line 107 in the structural example shown in FIG. 5A is different from that shown in FIG. 3A. In the structural example shown in FIG. 5A, the bias line 107 extends in the Y direction along the right end 216 of the photodiode (semiconductor layer) 121 so as to cover the right end 216. Two recesses 210C and 210D sandwiching the contact portion 323 in the Y direction are formed on the lower layer side of the bias line 107. Note that one of the recesses 210C and 210D may be omitted. In a plan view, the upper electrode 305 is excluded from the area overlapping with the recesses 210C and 210D and does not exist. The recesses 210C and 210D are formed outside the range covered by the upper electrode 305.

[0079] One end of the recess 210C in the longitudinal direction (Y direction) coincides with the end 215A of the photodiode semiconductor layer, and one end of the recess 210C in the lateral direction (X direction) coincides with the end 216 of the photodiode semiconductor layer. Thus, a part of the recess 210C overlaps with the end 215A of the photodiode semiconductor layer in a plan view, and another part overlaps with the end 216.

[0080] One end of the recess 210D in the longitudinal direction (Y direction) coincides with the end 215B of the photodiode semiconductor layer, and one end of the recess 210D in the lateral direction (X direction) coincides with the end 216 of the photodiode semiconductor layer. A part of the recess 210D overlaps with the end 215B of the photodiode semiconductor layer in a plan view, and another part overlaps with the end 216.

[0081] As described above, the edge of the photodiode semiconductor layer is formed by a stack of the remaining N-type amorphous silicon layer 202 and the intrinsic amorphous silicon layer 203. The recesses 210C and 210D have, for example, the same width and depth.

[0082] Fig. 5B shows a cross-sectional view taken along line VB-VB' in Fig. 5A. The recess 210C reaches the end of the photodiode semiconductor layer in the photodiode 121. In Fig. 5B, the upper side of the right end of the photodiode 121 is partially removed to form the recess 210C.

[0083] The recess 210C extends along the longitudinal direction of the bias line 107, and has an inner side surface on only one side in the lateral direction. The inner side surface is composed of a stack of the side surface of the upper electrode 305, the side surface of the P-type amorphous silicon layer 204, and the inner side surface of the recess of the intrinsic amorphous silicon layer 203. The opposite side of the inner side surface of the recess 210C is open.

[0084] The recesses 210C are formed by removing the right end of the photodiode 121 and its vicinity. Therefore, the height of the right end of the photodiode 121 is lower than the other portions. The recesses 210C are filled with the second interlayer insulating layer 275. The description of the recesses 210C with reference to FIG. 5B can also be applied to the recesses 210D.

[0085] At least a part or the whole of the recesses 210C and 210D is formed below the non-transparent bias line 107 and is covered by the bias line 107. Therefore, it is possible to suppress a decrease in photoelectric conversion efficiency caused by forming the recesses 210C and 210D.

[0086] 5B, one of the inner side walls of the recesses 210C and 210D does not exist, and one end in the short direction is open. Also, the height of the end (side wall) 216 of the photodiode semiconductor layer where the recesses 210C and 210D are formed is lowered by the recesses 210C and 210D.

[0087] In this way, by forming the recess along the edge of the semiconductor layer of the photodiode, the exposed area of ​​the sidewall of the photodiode that is damaged by etching is reduced, and the generation of defect levels in the photodiode due to etching damage is suppressed, thereby suppressing an increase in dark current.

[0088] Another structural example of the detection region 12 will be described. Fig. 6 is a plan view showing a schematic diagram of another structural example including the pixel 13, the gate line 105, the data line 106, and the bias line 107. In Fig. 6, only the outline of the bias line 107 is shown by a dashed line, and the recess 210 below the bias line 107 and the intrinsic amorphous silicon layer 203 are drawn through the bias line 107. The following mainly describes the differences from the configuration described with reference to Figs. 5A and 5B.

[0089] The photodiode semiconductor layer includes a protruding portion 213. The protruding portion of the upper electrode 305 overlaps a part of the protruding portion 213, and a contact portion 323 is formed at that part. The bias line 107 covers at least a part of the protruding portion 213, and does not cover the part of the photodiode semiconductor layer other than the protruding portion 213. A part of the upper layer side in the plane of the protruding portion is removed, and recesses 210E and 210F that sandwich the contact portion 323 are formed. Note that one of the recesses 210E and 210F may be omitted. The upper electrode 305 is excluded from the region that overlaps with the recesses 210E and 210F in a plan view, and does not exist. The recesses 210E and 210F are formed outside the range covered by the upper electrode 305. The length of the recesses 210E and 210F in the longitudinal direction (Y direction) is shorter than the length of the recesses 210C and 210D in the longitudinal direction shown in FIG. 5A.

[0090] <Embodiment 3> Another structural example of the detection region 12 will be described. FIG. 7 is a cross-sectional view of a region including the pixel 13, and corresponds to FIG. 3B. In the following, differences from the structural example shown in FIG. 3B will be mainly described. This embodiment includes an etching protection layer 307 on the upper electrode 305. The etching protection layer 307 has, for example, the same pattern shape as the upper electrode 305 and covers the entire area. In the example shown in FIG. 7, the etching protection layer 307 and the upper electrode 305 have the same shape and dimensions, that is, are congruent, but they may be similar shapes in which the pattern shapes are the same and only the dimensions are larger. The etching protection layer 307 can be formed of, for example, silicon nitride or silicon oxide.

[0091] In this embodiment, in order to form the recess, at least the upper electrode 305 and the upper layer of the amorphous silicon layer are removed by etching. As a method for etching the amorphous silicon, for example, dry etching is considered. To form a pattern in the amorphous silicon layer, the amorphous silicon is masked with a resist, or the amorphous silicon is etched using the upper electrode 305 as a mask.

[0092] Etching of amorphous silicon damages the upper electrode 305, which may change the film quality and film adhesion, and may cause, for example, film peeling between the upper electrode 305 and the second interlayer insulating layer 275. In this embodiment, an etching protection layer 307 for protecting the upper electrode 305 from etching is provided above the upper electrode 305, for example, in direct contact with the upper electrode 305, and the amorphous silicon layer is etched using these as a mask. This makes it possible to reduce etching damage to the upper electrode 305.

[0093] Another structural example of the detection region 12 will be described. FIG. 8 is a cross-sectional view of a region including the pixel 13, and corresponds to FIG. 3B. In the following, differences from the structural example shown in FIG. 3B will be mainly described. In the structural example shown in FIG. 8, the width W1 of the recess 210G, that is, the size in the short side direction, is larger than the width W2 of the bias line 107. Furthermore, in a plan view, the end in the short side direction of the bias line 107 is located inside the end of the recess 210G of the photodiode semiconductor layer. In a plan view, the bias line 107 covers a part of the recess 210G so that both ends that define the width of the bias line 107 are located within the recess 210G.

[0094] When the recess 210G is narrower than the bias line width and the second interlayer insulating layer 275 is coated to conform to the shape of the recess, the cross-sectional shape of the bias line becomes V-shaped to conform to the shape of the second interlayer insulating layer 275, and voids may occur over a wide area. The voids may progress due to migration and lead to disconnection. By making the area of ​​the recess 210G larger than the bias line width and arranging the bias line 107 and the recess 210G so that the recess 210G includes the upper bias line 107 in a plan view, the shape of the bias line 107 can be made closer to flat, and voids can be suppressed.

[0095] <Embodiment 4> Another structural example of the detection region 12 will be described. FIG. 9A is a plan view showing a schematic diagram of another structural example including the pixel 13, the gate line 105, the data line 106, and the bias line 107. In FIG. 9A, only the outline of the data line 106 is shown by a broken line, and the structure below the data line 106 is drawn through the data line 106. In addition, the upper electrode 305 covers the entire area of ​​the lower electrode 301, and the outline of the lower electrode 301 is shown by a broken line. Note that, for example, the lower electrode 301 may not be partially covered by the upper electrode 305. FIG. 9B shows a cross-sectional view taken along the IXB-IXB′ cutting line in FIG. 9A. In the following, differences from the configuration described with reference to FIGS. 3A to 3D will be mainly described.

[0096] The data line 106 has a light shielding property against light with which the photodiode 121 performs photoelectric conversion. The bias line 107 may be either light shielding or transparent. In the structural example shown in FIGS. 9A and 9B, a recess 210H is formed in a region overlapping the data line 106 in a planar view. The bottom surface of the recess 210 exposes the intrinsic amorphous silicon layer 203. The recess 210H is formed outside the lower electrode 301 in a planar view. The lower electrode 301 may overlap the recess 210H partially or entirely in a planar view. The recess 210H is formed outside the range covered by the upper electrode 305.

[0097] In this embodiment, the upper layer portion of the photodiode semiconductor layer is removed in the region overlapping with the data line 106 in a plan view. This structure reduces kTC noise. In addition, the parasitic capacitance formed by the data line 106 and the upper electrode 305 or the impurity-doped amorphous silicon layer on the upper layer side can be reduced, thereby reducing data line noise.

[0098] The recess 210H reaches the end of the photodiode semiconductor layer across which the data line 106 crosses. That is, the end of the recess 210H in the Y direction coincides with the end (sidewall) of the photodiode semiconductor layer. This reduces the risk of disconnection of the data line 106. In the structural example shown in FIGS. 9A and 9B, the inner side surface of the recess 210H in the short direction (X direction) is formed by a stack of the side surface of the upper electrode 305, the side surface of the P-type amorphous silicon layer 204, and the inner side surface of the recess of the intrinsic amorphous silicon layer 203, but as described in the second embodiment, one end of the recess 210H may be open.

[0099] 9A and 9B, the region in which the recessed portion of the photodiode semiconductor layer is formed may overlap with wiring other than the bias line in a plan view. As described in the other embodiments above, the recessed portion of the photodiode semiconductor layer may also be formed under the bias line 107.

[0100] <Embodiment 5> Another structural example of the detection region 12 will be described. Fig. 10A is a plan view showing a schematic diagram of another structural example including the pixel 13, the gate line 105, the data line 106, and the bias line 107. In Fig. 10A, only the outline of the bias line 107 is shown by a dashed line, and the structure below the bias line 107 is drawn through the bias line 107. Fig. 10B shows a cross-sectional view taken along the XB-XB' cutting line in Fig. 10A. In the following, differences from the configuration described with reference to Figs. 3A to 3D will be mainly described.

[0101] Recesses 210I and 210J of the photodiode semiconductor layer are formed in the region covered by the bias line 107 in plan view. In the recesses 210I and 210J, the intrinsic amorphous silicon layer 203 is exposed, and the recesses 210I and 210J are formed outside the region covered by the upper electrode 305.

[0102] In plan view, the recess 210I covers at least a part of the contact portion 227 between the source electrode 253 and the lower electrode 301. In plan view, only a part of the contact portion 227 including the center in plan view may overlap with the recess 210I.

[0103] If a high step exists on the lower layer side of the amorphous silicon layer region, the film quality of the amorphous silicon layer spanning the step deteriorates, and defect levels are more likely to occur than in a flat area. A step may exist when the contact portion 227 between the source electrode 253 and the lower electrode 301 of the thin film transistor 122 exists on the lower layer side of the region overlapping with the amorphous silicon layer in a plan view. The step deteriorates the dark current characteristics of the photodiode 121 located above it. An increase in dark current can be suppressed by removing the impurity-doped amorphous silicon layer above the step, where the characteristics are likely to deteriorate, and eliminating the vertical electric field between the upper and lower impurity-doped amorphous silicon layers.

[0104] <Embodiment 6> Another structural example of the detection region 12 will be described. FIG. 11A is a plan view showing a schematic diagram of another structural example including the pixel 13, the gate line 105, the data line 106, and the bias line 107. In FIG. 11A, only the outline of the bias line 107 is shown by a broken line, and the structure below the bias line 107 is drawn through the bias line 107. FIG. 11B shows a cross-sectional view taken along the line XIB-XIB' in FIG. 11A. In the following, differences from the configuration described with reference to FIGS. 3A to 3D will be mainly described.

[0105] 3A to 3D, recesses 210K and 210L are formed. The bottom surface of the recess 210K is gradually lowered toward the end 215A of the photodiode semiconductor layer. The bottom surface of the recess 210L is gradually lowered toward the end 215B of the photodiode semiconductor layer.

[0106] 11B, the bottom surface of recess 210K is composed of two step surfaces 217A and 217B with different heights. The height of step surface 217B from lower electrode 301 is lower than the height of step surface 217A from lower electrode 301. Step surface 217A exists between contact portion 323 and step surface 217B. Step surface 217B reaches end 215A of the photodiode semiconductor layer (N-type amorphous silicon layer 202 and intrinsic amorphous silicon layer 203).

[0107] The bottom surface of recess 210L is composed of two step surfaces 217C and 217D with different heights. The height of step surface 217D from lower electrode 301 is lower than the height of step surface 217C from lower electrode 301. Step surface 217C exists between contact portion 323 and step surface 217D. Step surface 217D reaches end 215B of the photodiode semiconductor layer (N-type amorphous silicon layer 202 and intrinsic amorphous silicon layer 203).

[0108] In this way, the bottom surface of the recess is composed of multiple step surfaces, and the height decreases toward the end, thereby reducing the possibility of step breakage of the upper layer bias line 107. The number of step surfaces on the bottom surface may be three or more. In the configuration example shown in FIG. 5A, 5B, or 6, the bottom surface of the recess 210L may be stepped down toward the end 215B of the photodiode semiconductor layer.

[0109] <Embodiment 7> Another structural example of the detection region 12 will be described. Fig. 12 is a plan view that shows a schematic diagram of another structural example including pixels 13, gate lines 105, data lines 106, and bias lines 107. In the following, differences from the configuration described with reference to Fig. 5A will be mainly described.

[0110] 5A, the data line 106 and the bias line 107 are formed in the same layer. In this embodiment, the data line 106 is disposed in a layer below the bias line 107. In one example, the data line 106 is formed in the same layer as the source electrode 253 and the drain electrode 254 of the thin film transistor 122.

[0111] For example, when the bias line 107 is disposed at the end of the photodiode semiconductor layer, it is close to the data line 106 of the adjacent pixel, and noise is likely to occur between the data line 106 and the bias line 107. By disposing the data line 106 in the same layer as the source electrode 253 and the drain electrode 254, the distance between the data line 106 and the bias line 107 can be increased, and noise in the data line can be reduced.

[0112] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. A person skilled in the art can easily change, add, or convert each element of the above embodiments within the scope of the present disclosure. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. [Explanation of symbols]

[0113] 10 Image Sensor 11 Sensor board 13 pixels 14 Drive circuit 16 Signal detection circuit 18 Main control circuit 105 Gate Line 106, 161 Data line 107 Bias Wire 121 Photodiode 122 Thin-film transistor 202 N-type amorphous silicon layer 203 Intrinsic amorphous silicon layer 204 P-type amorphous silicon layer 210 Recess 251 Gate electrode 252 Semiconductor Department 253 Source Electrode 254 Drain electrode 271 Insulating Substrate 272-276 Insulating layer 301 Lower electrode 305 Upper electrode

Claims

1. 1. An imaging device, comprising: A substrate; a photodiode semiconductor layer on the substrate; an upper electrode and a lower electrode sandwiching the photodiode semiconductor layer; the substrate being the lowest layer, and a light-shielding wiring layer above the upper electrode; Including, The photodiode semiconductor layer comprises: A first semiconductor layer; a second semiconductor layer between the first semiconductor layer and the lower electrode; Including, the photodiode semiconductor layer includes a recess in a region covered by the light-shielding wiring in a plan view, the first semiconductor layer being removed; the upper electrode is excluded from a region overlapping with the recess in the plan view; a portion of the second semiconductor layer and a portion of the lower electrode are present in a region overlapping with the recess in the plan view; Imaging device.

2. 2. The imaging device according to claim 1, the photodiode semiconductor layer includes a third semiconductor layer between the first semiconductor layer and the second semiconductor layer, a bottom surface of the recess is formed of a part of the third semiconductor layer; Imaging device.

3. 3. The imaging device according to claim 2, The third semiconductor layer has a recess that constitutes a part of the recess. Imaging device.

4. 2. The imaging device according to claim 1, the light-shielding wiring is a bias line that applies a bias potential to the photodiode semiconductor layer via the upper electrode; Imaging device.

5. 2. The imaging device according to claim 1, the light-shielding wiring crosses an edge of the second semiconductor layer in the plan view, an edge of the recess coincides with an edge of the second semiconductor layer in a plan view; Imaging device.

6. 2. The imaging device according to claim 1, the light-shielding wiring extends along an edge of the second semiconductor layer and covers the edge; the recess extends along the edge; an edge of the recess coincides with an edge of the second semiconductor layer in a plan view; Imaging device.

7. 2. The imaging device according to claim 1, Further comprising an insulating layer covering the upper electrode and having a pattern shape similar or congruent to the upper electrode; Imaging device.

8. 2. The imaging device according to claim 1, the width of the light-shielding wiring is smaller than the width of the recess; the light-shielding wiring covers a part of the recess so that both ends defining a width of the light-shielding wiring are within the recess in the plan view; Imaging device.

9. 2. The imaging device according to claim 1, the light-shielding wiring is a data line for transmitting a signal from the photodiode semiconductor layer; Imaging device.

10. 2. The imaging device according to claim 1, further comprising a transistor connected to the bottom electrode; In the plan view, the recess covers at least a part of a contact portion between the transistor and the lower electrode. Imaging device.

11. 6. The imaging device according to claim 5, A bottom surface of the recess is gradually lowered toward the end of the second semiconductor layer. Imaging device.

12. 2. The imaging device according to claim 1, Further comprising a data line for transmitting a signal from the photodiode semiconductor layer, the light-shielding wiring is a bias line that applies a bias potential to the photodiode semiconductor layer via the upper electrode, the data lines and the bias lines extend along a common direction; The data line is disposed below the bias line. Imaging device.

Images