JP2010245076A - Photoelectric converter, x-ray imaging apparatus, and method of manufacturing the photoelectric converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric converter for reducing capacitive coupling. <P>SOLUTION: The photoelectric converter includes: a light detection region divided into a plurality of pixel regions; a photoelectric conversion element 25 that is disposed at each of the plurality of pixel regions and has a photoelectric conversion layer sandwiched between a first electrode 251 and a second electrode 252; first wiring 222 that is electrically connected to the first electrode 251 and is extended in a first direction; and second wiring 23 that is electrically connected to the second electrode 252, is disposed at a position separated from the first wiring 251 in a thickness direction of the photoelectric conversion layer, and is extended in a second direction crossing the first direction. The first wiring 222 is divided into parts at a crossing section 26 where the first direction crosses the second direction. An energization path including the first wiring 222 includes a connection conductive section 261 provided at a position more separated from the second wiring 23 than the first wiring 222 in a thickness direction of the crossing section 26. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion device, an X-ray imaging device, and a method for manufacturing a photoelectric conversion device.

  Conventionally, an image sensor (photoelectric conversion device) that reads an image by detecting light incident on a photodiode has been proposed. The image sensor includes, for example, a plurality of pixel regions arranged in a matrix. In each of the plurality of pixel regions, a photodiode and a thin film transistor (hereinafter abbreviated as TFT) are provided. One electrode of the photodiode is electrically connected to the source of the TFT. The other electrode of the photodiode is a common electrode common to the plurality of pixel regions. The drains of the plurality of TFTs arranged in the row direction are collectively electrically connected to the data line. The gates of the plurality of TFTs arranged in the column direction are collectively connected to the scanning line.

  In such an image sensor, when light enters the photodiode, a charge is generated in the photodiode. When a voltage is applied to the scanning line, the TFT is turned on, and charges (data) generated in the photodiode are read out to the data line. An image can be read by sequentially reading out charges from a plurality of pixel regions.

  In recent years, attempts have been made to apply an image sensor to an X-ray imaging apparatus (for example, Patent Document 1). As one of the X-ray imaging devices, a combination of a scintillator that emits fluorescence or the like when receiving X-rays with an image sensor is considered. The X-ray imaging apparatus is considered to be applied to medical equipment, for example. The X-ray imaging apparatus has an advantage that a fluoroscopic image can be obtained in real time as compared with a still image imaging apparatus using an X-ray film or the like. In addition, there is an advantage that a high-resolution fluoroscopic image can be obtained as compared with a moving image pickup apparatus combining a photomultiplier tube and a CCD element.

  The photoelectric conversion apparatus and the X-ray imaging apparatus as described above are expected to have high sensitivity and high resolution. One effective method for achieving high sensitivity and the like is a method of preventing deterioration due to capacitive coupling of data taken out via a data line. Patent Document 1 discloses a method of reducing the area of the common electrode that overlaps the data line by patterning the common electrode.

Japanese Patent Laid-Open No. 9-247533

According to the technique of Patent Document 1, it is considered that the capacitive coupling between the pixel electrode and the data line can be reduced, but there is a point that should be further improved from the viewpoint of reducing the capacitive coupling.
In Patent Document 1, a common electrode is formed of a transparent conductive material such as indium tin oxide (ITO) as usual in order to make light incident on the semiconductor layer of the photodiode. In general, a transparent conductive material has lower conductivity than a metal such as aluminum. Therefore, according to the technique of Patent Document 1, capacitive coupling can be relatively reduced as compared with the case where the common electrode is formed in a solid shape, but it cannot be said that the absolute value of capacitive coupling can be sufficiently reduced.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a photoelectric conversion device and an X-ray imaging device with reduced capacitive coupling. Another object is to provide a method by which a photoelectric conversion device with reduced capacitive coupling can be efficiently manufactured.

  The photoelectric conversion device of the present invention includes a light detection region partitioned into a plurality of pixel regions, and a photoelectric conversion layer disposed in each of the plurality of pixel regions and sandwiched between a first electrode and a second electrode. A photoelectric conversion element, a first wiring electrically connected to the first electrode and extending in the first direction, and electrically connected to the second electrode, the first conversion electrode in the thickness direction of the photoelectric conversion layer A second wiring disposed in a position away from one wiring and extending in a second direction intersecting the first direction, wherein the first wiring includes the first direction and the second direction. The energization path including the first wiring is connected at a position farther from the second wiring than the first wiring in the thickness direction of the intersection. A conductive portion is included.

  In this way, since the energization path including the first wiring passes through the connection conductive portion provided at a position farther away from the second wiring in the thickness direction than the first wiring at the intersection, the connection conductive The capacitive coupling at the intersection is reduced by the amount that the part is separated from the first wiring. Accordingly, generation of noise or the like in the electrical signal passing through the first wiring or the second wiring due to capacitive coupling is reduced, and the charge (data) generated in the photoelectric conversion layer is accurately read through the first wiring or the second wiring. Is possible. As a result, an electrical signal corresponding to light is obtained from each of the plurality of pixel regions, so that a highly sensitive photoelectric conversion device capable of obtaining a high-resolution image is obtained.

  The second electrode is disposed on the light incident side of the photoelectric conversion element, the second electrode is made of a transparent conductive material, and the second wiring has a conductivity higher than that of the transparent conductive material. It should be made of high metal material. In this case, it is preferable that the second electrode is provided at a position that does not overlap the first wiring in the thickness direction.

  In this case, since the second wiring is made of a metal material having a higher conductivity than the transparent conductive material, the second electrode can be substantially reduced in resistance by the second wiring. Capacitive coupling with the first wiring can be reduced. Furthermore, if the second electrode is provided at a position that does not overlap the first wiring in the thickness direction, capacitive coupling between the second electrode and the first wiring can be significantly reduced.

And a field effect transistor including a gate electrode, a gate insulating film provided on the gate electrode, and a channel region provided on the gate insulating film, wherein the first electrode and the first wiring are provided. Are electrically connected via the channel region, and the gate electrode may be formed on the same layer with the same forming material as the connection conductive portion.
In this way, since the connection conductive portion can be formed in the same process as the gate electrode, a low-cost photoelectric conversion device can be obtained.

An insulating film provided over the first wiring, the photoelectric conversion element, and the second wiring; and an external connection terminal that penetrates the insulating film and is electrically connected to the second wiring. The connection conductive part may be formed on the same layer with the same forming material as the external connection terminal.
In this way, since the connection conductive portion can be formed in the same process as the external connection terminal, a low-cost photoelectric conversion device can be obtained.

  In addition, the second wiring is divided at the intersection, and the second energization path including the second wiring is closer to the first wiring than the second wiring in the thickness direction of the intersection. It is preferable to include a second connection conductive portion provided at a distant position. In this case, an insulating film provided over the first wiring, the photoelectric conversion element, and the second wiring, and an external through the insulating film and electrically connected to the second wiring It is preferable that the second connection conductive portion is formed on the same layer with the same material as that of the external connection terminal.

  In this case, the second energization path including the second wiring passes through the second connection conductive portion provided at a position farther from the first wiring in the thickness direction than the second wiring at the intersection. Therefore, the capacitive coupling at the intersection is reduced by the amount that the second connection conductive portion is separated from the second wiring. Therefore, the capacitive coupling can be reduced by the amount that the connection conductive portion is separated from the first wiring and the amount that the second connection conductive portion is separated from the second wiring, and the capacitive coupling is significantly reduced. be able to.

  The method for manufacturing a photoelectric conversion device according to the present invention includes a step of collectively forming a gate electrode and a connection conductive portion extending in the first direction on a substrate, over the gate electrode and the connection conductive portion. Forming a gate insulating film; forming a semiconductor layer including a channel region on the gate insulating film; and forming at least two first through holes in the gate insulating film in the first direction. Exposing the connection conductive portions in at least two regions separated from each other in the first through hole; electrically connected to the channel region; and divided between the two first through holes; and Forming a first wiring electrically connected to the connection conductive portion in each of the two first through holes, and forming a first electrode electrically connected to the first wiring through the channel region; And the first Forming a photoelectric conversion layer on the pole, and forming, on the photoelectric conversion layer, a second wiring that extends in a second direction that intersects the first direction and is divided at an intersection with the first direction. Forming a second electrode that is conductively connected to the second wiring; forming an insulating film covering the second electrode, the second wiring line, and the first wiring; and A second through hole is formed in the film to expose a part of the first wiring in the second through hole, and at least two third through holes are formed to be separated from each other in the second direction. Exposing the second wiring in at least two regions into the third through-hole, and connecting external connection terminals electrically connected to the second wiring in the second through-hole and on the insulating film And a second conductively connected to the second wiring And having a step of forming collectively with the external connecting terminals over the respective connection conductor portions within said insulating film and said two third holes and the.

  If it does in this way, the space | interval of the electricity supply path | route containing 1st wiring and the 2nd electricity supply path | route containing 2nd wiring will become the space | interval of a connection conductive part and a 2nd connection conductive part in an intersection. Therefore, compared to the case where the first wiring and the second wiring that are not divided at the intersection are formed, the interval between the energization paths is increased by the total thickness of the gate insulating film and the insulating film, and the distance between the energization paths is increased. Is significantly reduced. In addition, since the gate electrode and the connection conductive portion are formed at once, and the external connection terminal and the second connection conductive portion are formed at the same time, the increase in man-hours due to the formation of the connection conductive portion is minimized. In short, the connection conductive portion can be formed without increasing the number of steps. As described above, according to the present invention, it is possible to efficiently manufacture a photoelectric conversion device in which capacitive coupling is significantly reduced.

The X-ray imaging device of the present invention includes the photoelectric conversion device of the present invention, a light conversion unit that converts incident X-rays into light having a longer wavelength than the X-rays, and emits the light toward the photoelectric conversion device. It is characterized by providing.
According to the photoelectric conversion device of the present invention, a high-resolution image can be obtained. Therefore, the X-ray imaging device of the present invention can obtain a high-resolution perspective image. In addition, the X-ray irradiation amount can be reduced while ensuring the resolution of the fluoroscopic image to a certain degree or more, and the load of the X-ray on the subject can be reduced.

It is a perspective view which shows schematic structure of an X-ray imaging device. It is a schematic diagram which shows the circuit structure of a photoelectric conversion apparatus. It is a top view which shows the structure of a pixel area. FIG. 4 is a sectional view taken along line B-B ′ in FIG. 3. 3A is a cross-sectional view taken along line C-C ′ in FIG. 3, and FIG. 4B is a cross-sectional view taken along line D-D ′ in FIG. 3. (A) of a 1st external connection terminal is a top view, (b) is sectional drawing. (A) of a 2nd external connection terminal is a top view, (b) is sectional drawing. (A)-(e) is process drawing which shows schematically the manufacturing method of a photoelectric conversion apparatus. (A)-(c) is process drawing which continues from FIG.8 (e). (A), (b) is process drawing which continues from FIG.9 (c).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings used for explanation, in order to show characteristic parts in an easy-to-understand manner, dimensions and scales of structures in the drawings may be different from actual structures. In addition, in the embodiment, the same components are illustrated with the same reference numerals, and detailed description thereof may be omitted.

  FIG. 1 is a perspective view showing a schematic configuration of an X-ray imaging apparatus 1 according to the present embodiment. As shown in FIG. 1, the X-ray imaging device 1 includes a photoelectric conversion device 2 and a scintillator (light conversion unit) 3. The photoelectric conversion device 2 is an application of the photoelectric conversion device of the present invention.

  The photoelectric conversion device 2 has a substantially rectangular light detection region A1. The light detection area A1 is partitioned into a plurality of pixel areas A2 having a substantially rectangular shape. The plurality of pixel areas A2 are arranged in a matrix. A photoelectric conversion element, which will be described later, is arranged in each of the plurality of pixel regions A2. A plurality of first external connection terminals 211 are provided in a peripheral portion (frame) along one side of the light detection region A1. The first external connection terminal 211 is connected to the scanning line driving circuit 21. A plurality of second external connection terminals 221 are provided in the peripheral portion along the other side of the light detection region A1. The second external connection terminal 221 is connected to the data line driving circuit 22. The X-ray imaging apparatus 1 generally operates as follows.

  For example, the X-ray imaging apparatus 1 is a medical device, and the imaging target 9 is a person. The X-ray L1 emitted from the emission source 8 of the X-ray L1 enters the imaging target 9. A part of the X-ray L1 incident on the imaging object 9 is scattered and absorbed by the imaging object 9. Thereby, the intensity distribution of the X-ray L2 that has passed through the imaging object 9 is a distribution that reflects the internal composition and internal structure of the imaging object 9. The X-ray L2 that has passed through the imaging object 9 enters the scintillator 3. The scintillator 3 is formed of a film made of cesium iodide (CsI) or the like, and is actually disposed in contact with the light detection region A1 side of the photoelectric conversion device 2. The scintillator 3 converts the incident X-ray L2 into fluorescence L3 having a wavelength longer than that of the X-ray L2, and emits the converted X-ray. The intensity distribution of the emitted fluorescence L3 is a distribution reflecting the intensity distribution of the X-ray L2 incident on the scintillator 3.

  The fluorescence L3 emitted from the scintillator 3 is spatially divided and incident on the plurality of pixel regions A2 of the photoelectric conversion device 2. The light incident on the pixel area A2 generates charges in the photoelectric conversion elements arranged in the pixel area A2. This electric charge is read for each pixel region A2 by a read circuit described later, and becomes data indicating a fluoroscopic image of the imaging target 9. Hereinafter, the configuration of the photoelectric conversion device 2 will be described.

  FIG. 2 is a schematic diagram illustrating the configuration of the readout circuit of the photoelectric conversion device 2, and FIG. 3 is an enlarged plan view illustrating the planar configuration of the pixel region A2. In FIG. 3, some components of the photoelectric conversion device 2 are omitted for easy understanding of the drawing.

  As shown in FIG. 2, the readout circuit includes a plurality of scanning lines 212 extending in parallel with each other. The plurality of scanning lines 212 are electrically connected to the first external connection terminal 211 for each scanning line 212. It is connected. In other words, the plurality of scanning lines 212 are electrically connected to the scanning line driving circuit 21 via the first external connection terminal 211.

  A plurality of data lines (first wirings) 222 are extended along a first direction substantially orthogonal to the scanning lines 212. The plurality of data lines 222 are electrically connected to the second external connection terminal 221 for each data line 222. That is, the plurality of data lines 222 are electrically connected to the data line driving circuit 22 via the second external connection terminal 221.

  The scanning line driving circuit 21 and the data line driving circuit 22 each include a shift register, a level shifter, a video line, an analog switch, and the like. The scanning line driving circuit 21 and the data line driving circuit 22 are actually formed in an IC chip (not shown). The IC chip is mounted with the first external connection terminal 211 and the second external connection terminal 221 as connection portions.

  A plurality of bias lines (second wirings) 23 are extended along a second direction substantially parallel to the scanning line 212. As shown in FIG. 3, the data line 222 and the bias line 23 extend intermittently. The data line 222 is divided at the intersecting portion 26 and constitutes a continuous energization path via the connection conductive portion 261. The bias line 23 is divided at the intersecting portion 26, and constitutes a continuous second energization path via the second connection conductive portion 262. The detailed structure of the intersection 26 will be described later. The plurality of bias lines 23 are collectively connected to a ground line (not shown).

  Each of the areas partitioned by the scanning lines 212 and the data lines 222 is a pixel area A2. A photodiode (photoelectric conversion element) 25 is disposed in each of the plurality of pixel regions A2. In the pixel region A2, the TFT 24 is disposed in the vicinity of the region where the scanning line 212 intersects with the data line 222.

  The gate electrode 241 of the TFT 24 is formed integrally with the scanning line 212. A portion of the scanning line 212 that is formed to protrude to the pixel region A 2 is a gate electrode 241. The drain region 242 of the TFT 24 is conductively connected to a portion formed in the data line 222 so as to protrude from the pixel region A2. The source region 243 of the TFT 24 is electrically connected to the conductive portion 281. The first electrode (pixel electrode) 251 of the photodiode 25 is embedded in the contact hole H1, and is electrically connected to the conductive portion 281 in the contact hole H1. The transparent electrode 252 of the photodiode 25 is electrically connected to the bias line 23. The transparent electrode 252 of this embodiment is provided independently for each pixel region A2. The scanning line 212 and the data line 222 are provided between the pixel regions A2, and the transparent electrode 252 does not overlap the scanning line 212 and the data line 222 in a plane.

  When the fluorescence L3 is incident on the photodiode 25, an electric charge is generated in the photodiode 25. When a scanning signal is supplied from the scanning line driving circuit 21 to the scanning line 212, the plurality of TFTs 24 connected to the scanning line 212 are turned on. When the TFT 24 is turned on, the electric charge generated in the photodiode 25 flows through the channel region of the TFT 24 to the data line 222, and this current is read to the data line driving circuit 22 as an electric signal. In this way, electrical signals are read out in parallel from the plurality of TFTs 24 connected to one scanning line 212. After the electrical signal is read from the TFT 24 corresponding to one scanning line 212, the plurality of data lines 222 are discharged and held at a predetermined potential. After the plurality of data lines 222 reach a predetermined potential, the scanning signal is supplied from the scanning line driving circuit 21 to the next scanning line 212. Similarly, electrical signals corresponding to each of the charges generated in the plurality of photodiodes 25 are sequentially read out.

  4 is a cross-sectional view taken along line B-B ′ in FIG. 3. As shown in FIG. 4, the photoelectric conversion device 2 is formed using a substrate 20 as a base. A TFT 24 is provided on the substrate 20. The TFT 24 includes a gate electrode 241, a drain region 242, a source region 243, a gate insulating film 244, and a semiconductor layer 245.

  The gate electrode 241 is made of a conductive material selected as appropriate, for example, a simple substance or an alloy such as aluminum, molybdenum, titanium, silver, tantalum, chromium, or tungsten. The gate electrode 241 of this embodiment is made of aluminum / molybdenum. The gate insulating film 244 is provided so as to cover the gate electrode 241. Here, the gate insulating film 244 is provided on almost the entire surface of the substrate 20. The gate insulating film 244 is made of an insulating material such as silicon nitride or silicon oxide. The gate insulating film 244 of this embodiment is made of silicon nitride or the like and has a thickness of about 200 to 500 nm. The semiconductor layer 245 is made of, for example, polysilicon or amorphous silicon. The drain region 242 and the source region 243 are provided on the semiconductor layer 245 at positions separated from each other. The drain region 242 and the source region 243 are made of, for example, amorphous silicon into which impurities are implanted at a high concentration. In the semiconductor layer 245, a region between the drain region 242 and the source region 243 functions as a channel region.

  A data line 222 is provided in contact with the drain region 242. A conductive portion 281 is provided continuously from the source region 243 to the gate insulating film 244 and in contact with the source region 243. The data line 222 and the conductive portion 281 are made of, for example, aluminum / molybdenum. A first passivation film 291 that covers the data line 222, the conductive portion 281, the gate insulating film 244 and the like and protects the TFT 24 is provided. A first passivation film 291 is provided over almost the entire surface of the substrate 20. The first passivation film 291 is made of, for example, silicon nitride and has a thickness of about 200 nm to 500 nm.

  The first passivation film 291 is provided with a contact hole H1 leading to the conductive portion 281. A pixel electrode 251 is provided continuously in the contact hole H1 and on the first passivation film 291. The pixel electrode 251 is in contact with the conductive portion 281 in the contact hole H1. A p-type semiconductor layer 253, an i-type semiconductor layer 254, and an n-type semiconductor layer 255 are arranged in this order from the pixel electrode 251 side on the pixel electrode 251 drawn out on the first passivation film 291. The semiconductor layers 253 to 255 constitute a photoelectric conversion layer. A second electrode (transparent electrode) 252 is formed on the photoelectric conversion layer. The transparent electrode 252 is on the light incident side, and is made of a transparent conductive material such as indium tin oxide (ITO).

  A second passivation film 292 is provided to cover the photodiode 25 except for the central portion of the transparent electrode 252. Here, the second passivation film 292 is provided on almost the entire surface of the substrate 20. The second passivation film 292 is made of, for example, silicon nitride and has a thickness of about 200 to 500 nm. A planarizing film 293 made of a resin material or the like is provided so as to cover almost the entire surface of the substrate 20 except for the central portion of the photodiode 25.

  A bias line 23 is formed in contact with the central portion of the transparent electrode 252 exposed between the planarization films 293. The bias line 23 is made of a conductive material having higher conductivity than the transparent electrode 252, for example, aluminum / molybdenum.

  A third passivation film (insulating film) 294 is provided to cover the planarization film 293, the photodiode 25 exposed between the planarization film 293, and the bias line 23. A third passivation film 294 is provided on almost the entire surface of the substrate 20. The third passivation film 294 is made of, for example, silicon nitride and has a thickness of about 200 to 500 nm.

  Next, the structure of the intersection 26 will be described with reference to FIGS. 5 (a) and 5 (b). 5A is a cross-sectional view taken along line C-C ′ in FIG. 3, and FIG. 5B is a cross-sectional view taken along line D-D ′ in FIG. 3. As shown in FIGS. 5A and 5B, the data line 222 is divided at the intersection 26, and the bias line 23 is also divided at the intersection 26.

On the substrate 20, a connection conductive portion 261 is provided in a portion overlapping the two end portions of the divided data line 222 in a plan view. A gate insulating film 244 is provided between the connection conductive portion 261 and the data line 222. The gate insulating film 244 is provided with two contact holes (first through holes) H2 and H3. The contact hole H2 communicates with one end portion of the data line 222 and the connection conductive portion 261. The contact hole H3 communicates with the other end portion of the data line 222 and the connection conductive portion 261. A part of the data line 222 is embedded in the contact holes H2 and H3. One end and the other end of the data line 222 are in contact with the connection conductive portion 261 in the contact holes H2 and H3, respectively. In other words, the data line 222 has a structure in which two divided portions are bridged by the connection conductive portion 261.
The connection conductive portion 261 is formed together with the gate electrode 241. The connection conductive portion 241 is provided on the same layer (on the substrate 20) as the gate electrode 241 and is made of the same material as the gate electrode 241.

  Similarly to the data line 222, the bias line 23 has a structure in which the divided portion is connected to the second connection conductive portion 262 and the two portions are bridged by the connection conductive portion 261. Specifically, as shown in FIG. 5B, the bias line 23 is covered with a third passivation film 294. The third passivation film 294 is provided with contact holes (third through holes) H4 and H5. The contact holes H4 and H5 communicate with one end and the other end of the divided bias line 23. A second connection conductive portion 262 is provided continuously in the contact holes H4 and H5 and on the third passivation film 294.

  The second connection conductive portion 262 is formed together with the first external connection terminal 211 and the second external connection terminal 221. The second connection conductive portion 262 is provided on the same layer as the first external connection terminal 211 and the second external connection terminal 221 (on the third passivation film 294), and the first external connection terminal 211 and the second external connection terminal 221 are provided. It is made of the same forming material as that of the connection terminal 221.

  Next, the structure of the first external connection terminal 211 and the second external connection terminal 221 will be described. 6A is a plan view of the first terminal portion including the first external connection terminal 211, and FIG. 6B is a cross-sectional view of the first terminal portion. FIG. 7A is a plan view of the second terminal portion including the second external connection terminal 221, and FIG. 7B is a cross-sectional view of the second terminal portion. In FIG. 6A and FIG. 7A, illustration of an insulating film or the like is omitted for easy understanding of the drawings.

  As shown in FIGS. 6A and 6B, the first terminal portion includes the end of the scanning line 212, the conductive portions 282 to 284, and the first external connection terminal 211. The conductive portion 282 is provided on the same layer as the data line 222 (on the gate insulating film 244) and is made of the same material as the data line 222. The conductive portion 282 is provided at a position where a part thereof overlaps with the end portion of the scanning line 212 in a plan view. A part of the conductive portion 282 is embedded in a contact hole H6 provided in the gate insulating film 244, and is in contact with the scanning line 212 in the contact hole H6 to be conductive.

  The conductive portion 283 is provided on the same layer as the pixel electrode 251 (on the first passivation film 291) and is made of the same material as that for the pixel electrode 251. The conductive portion 283 is provided at a position where a part thereof overlaps with a part of the conductive portion 282 in a plan view. A part of the conductive portion 283 is embedded in a contact hole (second through hole) H7 provided in the first passivation film 291 and is in contact with the conductive portion 282 in the contact hole H7 to be conductive.

  The conductive portion 284 is provided on the same layer (on the planarizing film 293) as the bias line 23 and is made of the same material as that for the bias line 23. A contact hole H8 is provided in the second passivation film 292 on the conductive portion 283. The planarizing film 293 over the contact hole H8 is opened. The conductive portion 284 is continuously formed in the contact hole H8, in the opening of the planarizing film 293, and on the planarizing film 293. A part of the conductive part 284 is in contact with the conductive part 283 in the contact hole H8 and is conductive.

  A contact hole H <b> 9 is provided in the third passivation film 294 on the conductive portion 284 in a portion formed on the planarizing film 293. A first external connection terminal 211 is provided in the contact hole H9 and on the third passivation film 294. The first external connection terminal 211 of this embodiment is made of ITO, and also functions as a protective film that protects the conductive portion 284 and the like from corrosion and oxidation. A driver IC (not shown) including the scanning line driving circuit 21 is mounted on the first external connection terminal 211 by a known mounting technique, for example, ACF connection using an anisotropic conductive film.

  As shown in FIGS. 7A and 7B, the second terminal portion includes the end of the data line 222, the conductive portions 285 and 286, and the second external connection terminal 221. In the second terminal portion, the structure of the gate insulating film 244 is substantially the same as that of the first terminal portion. That is, the conductive portion 285 is formed of the same forming material on the same layer as the pixel electrode 251 similarly to the conductive portion 283, and is in contact with the data line 222 in the contact hole H10. The conductive portion 286 is formed of the same material as the bias line on the same layer as the conductive portion 284, and is in contact with the conductive portion 285 in the contact hole H11. A contact hole (second through hole) H12 is provided in the third passivation film 294 on the conductive portion 286 in a portion formed on the planarizing film 293. A second external connection terminal 221 is provided in the contact hole H12 and on the third passivation film 294. The second external connection terminal 221 is made of the same material as that of the first external connection terminal 211. A driver IC (not shown) including the data line driving circuit 22 is mounted on the second external connection terminal 221.

  In the photoelectric conversion device 2 configured as described above, the transparent electrode 252 is independent for each pixel region A2, and is not provided between the pixel regions A2. Thereby, since the transparent electrode 252 and the data line 222 do not overlap, the capacitive coupling between the transparent electrode 252 and the data line 222 is reduced.

  The plurality of transparent electrodes 252 are collectively connected to the bias line 23 and substantially function as a common electrode, so that the drive system is prevented from becoming complicated. The second energization path including the bias line 23 intersects the energization path including the data line 222 at the intersection 26. Since the bias line 23 is made of a material having higher conductivity than the transparent electrode 252, capacitive coupling is reduced as compared with a configuration in which the transparent electrode overlaps the data line in place of the bias line 23.

  At the intersection 26, the second energization path including the bias line 23 bypasses the data line 222 to a position farther from the bias line 23 through the second connection conductive portion 262. In addition, the energization path including the data line 222 bypasses the bias line 23 and away from the data line 222 via the connection conductive portion 261. Therefore, the interval between the energization path and the second energization path at the intersection 26 is widened by the total thickness of the thickness of the gate insulating film 244 and the thickness of the third passivation film 294, so that the energization path is not detoured. Capacitive coupling between current paths is reduced.

  As described above, in the photoelectric conversion device 2, the capacitive coupling of the data line 222 is significantly reduced, so that the occurrence of noise or the like in the data read via the data line 222 is significantly reduced. . Therefore, the charges generated in the photodiode 25 can be accurately read, and a high-resolution image can be obtained.

  Moreover, in the X-ray imaging apparatus 1, since the fluorescence L3 emitted from the scintillator 3 is detected by the photoelectric conversion apparatus 2, the fluorescence L3 can be detected with high sensitivity. Therefore, a high-resolution fluoroscopic image can be obtained, and the strength of the X-ray L1 can be weakened while ensuring the quality of the fluoroscopic image. Thereby, the load which the imaging target 9 receives with the X-ray | X_line L1 can be reduced.

  The technical scope of the present invention is not limited to the above embodiment. Various modifications are possible without departing from the gist of the present invention. For example, in the above-described embodiment, both the two energization paths are detoured in directions away from each other, but only one of them may be detoured. Further, if necessary, a storage capacitor for holding charges generated in the photodiode 25, an amplifying TFT for amplifying current, and the like may be provided. When the capacitor line constituting the storage capacitor intersects with the bias line, the capacitor line is divided at the intersecting portion, and the dividing portion may be connected via the connection conductive portion similarly to the data line.

Next, a method for manufacturing a photoelectric conversion device according to the present invention will be described based on the photoelectric conversion device 2.
FIGS. 8A to 8E, FIGS. 9A to 9C, FIGS. 10A and 10B are process diagrams schematically showing a method for manufacturing the photoelectric conversion device 2. FIG. In these process drawings, the formation region A3 of the TFT 24 and the photodiode 25, the formation region A4 of the connection conductive portions 261 and 262 corresponding to the intersection 26, the formation region A5 of the first terminal portion, and the formation region A6 of the second terminal portion. Are shown in parallel. In the process diagram, the formation area A3 corresponds to the cross section shown in FIG. 4, the formation area A5 corresponds to the cross section shown in FIG. 6B, and the formation area A6 corresponds to the cross section shown in FIG. 7B. ing. For the formation region A4, the cross-section corresponding to FIG. 5A is shown in the step of forming the connection conductive portion 261 (FIGS. 8A to 8E), and after the formation of the connection conductive portion 261, FIG. In the process (FIGS. 9A to 9C, FIGS. 10A and 10B), a cross section corresponding to FIG. 5B is shown. In these process drawings, the fine structure is not shown.

  In order to manufacture the photoelectric conversion device 2, first, as shown in FIG. 8A, a conductive material (for example, aluminum / molybdenum) is formed on the substrate 20, and then this film is patterned to obtain a scanning line. 212, the gate electrode 241, and the connection conductive portion 261 are formed in a lump.

  Next, as shown in FIG. 8B, an insulating material (for example, silicon nitride) is formed on the entire surface of the substrate 20 over the scanning line 212, the gate electrode 241, and the connection conductive portion 261, thereby insulating the gate. A film 244 is formed. Then, a semiconductor layer 245 made of, for example, amorphous silicon is formed on a portion of the gate insulating film 244 that overlaps the gate electrode 241 in a planar manner. Then, a drain region 242 and a source region 243 are formed over or in the semiconductor layer 245. Thereby, the TFT 24 is formed.

  Next, as shown in FIG. 8C, contact holes H2 and H3 are formed in the portion of the gate insulating film 244 that overlaps with the connection conductive portion 261, and a part of the scanning line 212 is formed in the formation region A5 together with this. A contact hole H6 that exposes is formed. Then, a conductive material (for example, aluminum / molybdenum) is formed on almost the entire surface of the substrate 20 including the contact holes H2, H3, and H6 and the gate insulating film 244. Then, the data line 222 and the conductive portions 281 and 282 are collectively formed by patterning this film.

  Next, as shown in FIG. 8D, an insulating material (for example, silicon nitride) is formed on almost the entire surface of the substrate 20 including the conductive portion 282 and the data line 222, and a first passivation film 291 is formed. . Then, by patterning the first passivation film 291, contact holes H 1, H 7, H 10 are formed in a lump.

  Next, as shown in FIG. 8E, a conductive material (for example, aluminum / molybdenum) is formed on almost the entire surface of the substrate 20 over the contact holes H1, H7, and H10 and the first passivation film 291. Then, the pixel electrode 251 and the conductive portions 283 and 285 are collectively formed by patterning this film.

  Next, as illustrated in FIG. 9A, a p-type semiconductor layer 253, an i-type semiconductor layer 254, and an n-type semiconductor layer 255 are sequentially formed over the pixel electrode 251 to form a photoelectric conversion layer. . Then, a transparent electrode 252 made of a transparent conductive material such as ITO is formed on the photoelectric conversion layer. Thereby, the photodiode 25 is formed.

  Next, as shown in FIG. 9B, an insulating material (for example, silicon nitride) is formed on almost the entire surface of the substrate 20 to form a second passivation film 292. Then, by patterning the second passivation film 292, the central portion of the transparent electrode 252 is exposed and contact holes H8 and H11 are formed. Then, a planarizing film 293 is formed by forming a resin material on almost the entire surface of the substrate 20. In the planarizing film 293, the central portion of the transparent electrode 252 and the contact holes H8 and H11 are opened.

  Next, as shown in FIG. 9C, a conductive material (for example, aluminum) is formed on almost the entire surface of the substrate 20 including the central portion of the transparent electrode 252, the contact holes H8 and H11, the planarizing film 293, and the inside of the opening.・ Molybdenum) is deposited. Then, the bias line 23 and the conductive portions 284 and 285 are collectively formed by patterning this film.

  Next, as shown in FIG. 10A, an insulating material (for example, silicon nitride) is formed on almost the entire surface of the substrate 20 to form a third passivation film 294. Then, by patterning the third passivation film 294, contact holes H4, H5, H9, and H12 are collectively formed.

  Next, as shown in FIG. 10B, a conductive material (for example, ITO) is formed on almost the entire surface of the substrate 20 including the insides of the contact holes H4, H5, H9, and H12. Then, the second conductive portion 262, the first external connection terminal 211, and the second external connection terminal 221 are collectively formed by patterning this film. The photoelectric conversion device 2 is obtained by mounting the scanning line driving circuit 21 and the data line driving circuit 22. Furthermore, by providing the scintillator 3 corresponding to the light detection region A1 of the photoelectric conversion device 2, the X-ray imaging device 1 can be obtained.

In the manufacturing method of the present embodiment, the gate electrode 241 and the connection conductive portion 261 are formed in a lump, and the contact holes H2, H3, and H6 are formed in a lump. Therefore, the connection conductive portion 261 electrically connected to the data line 222 can be formed by the step of forming the TFT 24 and the step of forming the first external connection terminal, and an independent process for forming the connection conductive portion 261 is performed. do not need.
Further, the contact holes H4, H5, H9, and H12 are formed in a lump, and the second connection conductive portion 262 is formed in a lump with the first and second external connection terminals 211 and 221. Therefore, the second connection conductive portion 261 that is conductively connected to the bias line 23 can be formed by the step of forming the first and second terminal portions, and the second connection conductive portion 262 is formed independently. No process is required.
As described above, according to the manufacturing method of the present embodiment, the independent process for forming the connection conductive portions 261 and 262 can be simplified or omitted, and the capacitive coupling of the data line 222 is significantly reduced. The photoelectric conversion device 2 can be manufactured efficiently.

DESCRIPTION OF SYMBOLS 1 ... X-ray imaging device, 2 ... Photoelectric conversion device, 3 ... Scintillator, 23 ... Bias line (2nd wiring), 25 ... Photodiode, 26 ... Crossing part, 211. First external connection terminal (external connection terminal), 221 ... second external connection terminal (external connection terminal), 222 ... data line (first wiring), 241 ... gate electrode, 251 ... Pixel electrode (first electrode), 252... Transparent electrode (second electrode), 261... Connection conductive portion, 262... Second connection conductive portion, 294... Third passivation film (insulation) Film), A1... Light detection region, A2... Pixel region, H2, H3... Contact hole (first through hole), H4, H5... Contact hole (third through hole), H7, H12: Contact hole (second through hole)

Claims (9)

A light detection region partitioned into a plurality of pixel regions;
A photoelectric conversion element disposed in each of the plurality of pixel regions and having a photoelectric conversion layer sandwiched between a first electrode and a second electrode;
A first wiring electrically connected to the first electrode and extending in a first direction;
A second electrode electrically connected to the second electrode, disposed at a position away from the first wiring in the thickness direction of the photoelectric conversion layer, and extending in a second direction intersecting the first direction. And wiring,
The first wiring is divided at an intersection where the first direction and the second direction intersect,
The energization path including the first wiring includes a connection conductive portion provided at a position farther from the second wiring than the first wiring in the thickness direction of the intersection. Conversion device. The second electrode is disposed on a light incident side of the photoelectric conversion element;
2. The photoelectric conversion device according to claim 1, wherein the second electrode is made of a transparent conductive material, and the second wiring is made of a metal material having higher conductivity than the transparent conductive material.   The photoelectric conversion device according to claim 2, wherein the second electrode is provided at a position that does not overlap the first wiring in the thickness direction. A field effect transistor including a gate electrode, a gate insulating film provided on the gate electrode, and a channel region provided on the gate insulating film;
The first electrode and the first wiring are electrically connected via the channel region;
The photoelectric conversion device according to claim 1, wherein the gate electrode is formed on the same layer with the same forming material as the connection conductive portion. An insulating film provided over the first wiring, the photoelectric conversion element, and the second wiring; and an external connection terminal that penetrates the insulating film and is electrically connected to the second wiring. Prepared,
4. The photoelectric conversion device according to claim 1, wherein the connection conductive portion is formed on the same layer with the same material as the external connection terminal. 5.   The second wiring is divided at the intersection, and the second energization path including the second wiring is further away from the first wiring than the second wiring in the thickness direction of the intersection. The photoelectric conversion device according to claim 1, further comprising a second connection conductive portion provided at a position. An insulating film provided over the first wiring, the photoelectric conversion element, and the second wiring; and an external connection terminal that penetrates the insulating film and is electrically connected to the second wiring. Prepared,
The photoelectric conversion device according to claim 6, wherein the second connection conductive portion is formed on the same layer with the same material as that of the external connection terminal. Forming a gate electrode and a connection conductive portion extending in the first direction at a time on the substrate;
Forming a gate insulating film over the gate electrode and the connection conductive portion;
Forming a semiconductor layer including a channel region on the gate insulating film;
Forming at least two first through holes in the gate insulating film and exposing the connection conductive portions in at least two regions separated from each other in the first direction in the first through holes;
A first wiring is formed which is electrically connected to the channel region and is divided between the two first through holes and electrically connected to the connection conductive portion in each of the two first through holes. Process,
Forming a first electrode electrically connected to the first wiring through the channel region, and forming a photoelectric conversion layer on the first electrode;
A second wiring that extends in a second direction intersecting with the first direction and is divided at the intersection with the first direction is formed, and a second electrode that is conductively connected to the second wiring is formed. Process,
Forming an insulating film covering the second electrode, the second wiring line, and the first wiring;
A second through hole is formed in the insulating film to expose a part of the first wiring in the second through hole, and at least two third through holes are formed so as to be mutually in the second direction. Exposing the second wiring in at least two separate regions into the third through hole;
An external connection terminal electrically connected to the second wiring is formed in the second through hole and on the insulating film, and a second connection conductive portion electrically connected to the second wiring is insulated. And a step of collectively forming the external connection terminal over the film and within each of the two third through-holes. The photoelectric conversion device according to any one of claims 1 to 7,
An X-ray imaging apparatus comprising: a light conversion unit that converts incident X-rays into light having a longer wavelength than the X-rays and emits the light toward the photoelectric conversion device.

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