KR101078695B1 - A X-ray detector and a method for fabricating thereof - Google Patents

Abstract

The present invention relates to an x-ray image sensing device, and more particularly, to a signal application method of an x-ray image sensing device (DXD) and a configuration of an array wiring.

An object of the present invention is to provide an X-ray image sensing device that implements a high quality image by preventing signal delay.

For this purpose, the data signal wirings formed in one direction are cut at the center of the liquid crystal panel and spaced apart from each other, and data driving circuits are formed at both sides of the cut signal wirings, respectively.

In this way, since the data signal flows through the signal wiring whose length is reduced to 1/2 compared to the conventional one, since the line resistance can be reduced, the signal delay can be prevented by that much, thereby providing a high quality image. .

Description

X-ray detector and a method for manufacturing the same             

1 is a cross-sectional view for explaining the operation of the X-ray image sensing device,

2 is a plan view showing one pixel area of a conventional image sensing device;

3 is a plan view schematically illustrating a configuration of an image sensing device according to the related art;

4 is a plan view showing one pixel area of an image sensing device according to the present invention;

5 is a plan view schematically showing the configuration of an image sensing device according to the present invention;

6A through 6F are cross-sectional views taken along the line VV of FIG. 4 and shown in the process sequence of the present invention.

<Description of the symbols for the main parts of the drawings>

100 substrate 102 gate electrode

104: gate wiring 108: active layer

112 source electrode 114 drain electrode                 

116: first data wiring 118: second data wiring

120: grounding wiring 126: capacitor electrode

134: pixel electrode

The present invention relates to an X-ray image sensing device using a thin film transistor (TFT) array process and a method of manufacturing the same.

The diagnostic method of a diagnostic X-ray (X-ray) device, which is widely used for medical purposes today, was photographed using an X-ray detection film, and it was necessary to pass a predetermined film print time in order to know the result.

However, in recent years, with the development of semiconductor technology, digital X-ray detectors (hereinafter referred to as "X-ray image sensing devices") using thin film transistors have been researched and developed.

The X-ray image sensing device has an advantage of diagnosing a result by displaying an X-ray image on a screen in real time immediately after capturing the X-ray using a thin film transistor as a switching device.

Hereinafter, the configuration and operation of the X-ray image sensing device will be described.

FIG. 1 is a schematic diagram illustrating the structure and operation of an X-ray image sensing device, in which a substrate 1 is formed below, a thin film transistor 3, a storage capacitor 10, a pixel electrode 12, and a photoconductive film 2. ), The protective film 20, the high voltage electrode 24, the high voltage DC power supply 26, and the like.

The photoconductive film 2 forms an electrical signal, ie, electron and hole pair 6, internally in proportion to an external signal intensity such as incident electric waves or magnetic waves. The photoconductive film 2 serves as a converter for converting an external signal, in particular, an X-ray into an electrical signal. The electron-hole pair 6 formed by the X-ray light is provided under the photoconductive film 2 by the voltage Ev applied from the high voltage DC power supply 26 to the high voltage electrode 24 positioned on the photoconductive film 2. The pixel electrodes 12 positioned are collected in the form of electric charges and stored in the storage capacitor 10 formed together with the capacitor electrodes grounded from the outside. At this time, the charge stored in the storage capacitor 10 is turned on by the gate signal applied to the gate of the thin film transistor 3 and turned on through the data line connected to the source of the thin film transistor 3. It is sent to an image processing circuit to produce an x-ray image.

In order to detect and convert even weak X-ray light into charge in the X-ray image sensing device, the number of trap state densities trapping charge in the photoconductive film 2 is reduced, and the thin film transistor 3 is turned off. The leakage current when there is to be reduced.

2 is a plan view illustrating a pixel area of a conventional X-ray image sensing device.                         

As shown in the drawing, the gate lines 32 extending in one direction on the substrate 30 are configured in the row direction, and the data lines defining the pixel region P by crossing the gate lines 32 perpendicularly to each other ( 34) is configured.

The thin film transistor T is configured as a switching element at a portion where the gate line 32 and the data line 34 cross each other.

The thin film transistor T includes a gate electrode 44 in contact with the gate line 32, an active layer 46 formed on the gate electrode 44 with a gate insulating layer (not shown) interposed therebetween, and the active layer 46. The upper portion of the layer 46 includes a spaced source electrode 48 and a drain electrode 50.

In the pixel area P, a capacitor electrode 36 and a pixel electrode 38 are formed.

A ground wiring 40 is formed to be spaced apart from the gate wiring 32 by a predetermined distance, and the ground wiring 40 is formed under the capacitor electrode 38.

The ground wiring 40 and the capacitor electrode 36 are electrically connected to each other through the ground wiring contact hole 42.

In the above-described configuration, a silicon nitride film SiN _X is inserted into the dielectric material between the capacitor electrode 36 and the pixel electrode 38 to form a storage capacitor C _ST as a charge storage means.

Here, the pixel electrode 38 extends to the upper portion of the thin film transistor T, and although not shown, holes generated in the photoconductive film 2 of FIG. 1 may be accumulated in the storage capacitor C _ST . It serves as a collecting electrode to collect charges.

In addition, holes stored in the storage capacitor C _ST move to the source electrode 48 through the drain electrode 50, and are processed in an external circuit (not shown) via the data wire 34 to be represented as an image. do. The detailed operation thereof is the same as described with reference to FIG.

The overall configuration of the image sensing device having the pixel area configured as described above will be schematically described below with reference to FIG. 3.

3 is a plan view showing a schematic configuration of a conventional image sensing device.

As illustrated, the image sensing device 29 may be defined as a display area A and a driving area D1 and D3 representing an image. In the display area A, as described above with reference to FIG. 2, At the same time as the gate wiring and the data wiring are formed, a switching element, a photoconductive film and the like are formed in each pixel region.

In addition, driving regions D1 and D3 are defined in the periphery of the display area A, that is, one side of the image element and the other side not parallel thereto.

The first driving region D1 of the driving regions D1 and D3 is a portion corresponding to one end of the data line 34 of FIG. 2, and a data integrated circuit (not shown) is formed, and the second driving region ( D3) is a portion corresponding to one end of the gate wiring 32 in FIG. 2 and constitutes a gate integrated circuit (not shown).

However, such a configuration has a problem that signal delay occurs due to the longer the wiring length is, the higher the resolution, the worse the image quality.

Furthermore, in the case of data wiring, since the X-ray light plays a role of outputting a signal generated in the photoconductive film to the outside, there is a problem in that it has a great influence on the image quality of the image output to the outside depending on the resistance of the wiring.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to propose a configuration of a video surveillance device capable of obtaining high image quality by preventing signal delay due to data wiring and a manufacturing method thereof.

An x-ray image sensing device according to the present invention for achieving the above object comprises a plurality of gate wirings configured in one direction on a substrate; A first data line and a second data line defined to cross the gate line vertically with a gate insulating layer interposed therebetween to define a pixel area, and separated from one another in a central direction of the substrate; A switching element configured at a point where the first and second data lines and the gate line cross each other; A ground line formed in one direction in the pixel area; A first passivation layer formed on a front surface of the substrate on which the thin film transistor and the ground wiring are formed and patterned to expose a part of the ground wiring; A capacitor electrode in contact with the exposed ground line; A second passivation layer formed on a front surface of the substrate including the capacitor electrode and patterned to expose a portion of the switching element; And a pixel electrode in contact with the exposed switching element.

A data driving circuit is formed at one end of the first data line and one end of the second data line, and a gate driving circuit is formed at one end of the gate line.

A storage capacitor having a capacitor electrode in contact with the ground wiring as a first electrode and a pixel electrode thereon as a second electrode is configured.

The switching element includes a gate electrode, an active layer (and an ohmic contact layer), a source electrode and a drain electrode.

According to an aspect of the present invention, there is provided a method of manufacturing an X-ray image sensing device, including: defining a display area on a substrate and a driving area around the display area; Forming a gate wiring in one direction corresponding to the display area; Forming a pixel area by vertically intersecting the gate line with a gate insulating layer interposed therebetween, and forming a first data line and a second data line spaced apart in one direction from a center area of the substrate; Forming a switching element at a point where the first and second data lines and the gate line cross each other; Forming a ground line formed in one direction in the pixel area; Forming a first passivation layer formed on an entire surface of the substrate on which the switching element and the ground line are formed, and wherein the first passivation layer is patterned to expose a part of the ground line; Forming a capacitor electrode in contact with the exposed ground line; Forming a second passivation layer formed on a front surface of the substrate on which the capacitor electrode is formed and patterned to expose a portion of the switching element; Forming a pixel electrode in contact with the exposed switching element.

A data driving circuit is formed at one end of the first data line and one end of the second data line, and a gate driving circuit is formed at one end of the gate line.

Forming a photoconductive film on the pixel electrode; The method may further include forming a conductive electrode on the photoconductive film.

The photoconductive film is characterized in that the material selected from the group consisting of amorphous selenium (selenium), HgI ₂ , PbO, CdTe, CdSe, thallium bromide, cadmium sulfide.

Hereinafter, the configuration and operation according to the embodiment of the present invention will be described with reference to the accompanying drawings.

Example

According to an aspect of the present invention, when the data line is formed, the data line is cut at the center of the image sensing device, and thus, the data line is formed in a spaced shape, and the data driving circuit is formed on both sides of each cut data line. It features.

Hereinafter, the configuration of the image sensing device according to the present invention will be described with reference to FIG. 4.                     

4 is a schematic plan view of a portion of a display area of an X-ray image sensing device according to the present invention.

The first data line 116 and the second data line 118 are formed on the substrate 100 by cutting at a central portion of the substrate and spaced apart from each other.

The plurality of pairs of the first and second data wires 116 and 118 described above are spaced apart in the vertical direction.

A plurality of gate lines 104 are defined to vertically cross the first and second data lines 116 and 118 to define the pixel region P, and are spaced in parallel to each other.

A gate electrode 102, an active layer 108, a source electrode 112, and a drain electrode 114 are formed at the intersection of the gate wiring 104, the first data wiring, and the second data wiring 116, 118. The thin film transistor T is constituted.

In the pixel region P, a capacitor electrode 126 and a pixel electrode 134 are formed.

The ground wiring 120 is formed under the capacitor electrode 126, and the ground wiring 120 is in electrical contact with the capacitor electrode 126 through the ground wiring contact hole 124.

A silicon nitride film SiN _X is interposed between the capacitor electrode 126 and the pixel electrode 134 as a dielectric material to form a storage capacitor C _ST as a charge storage means.

Here, the pixel electrode 134 extends to the upper portion of the thin film transistor T, and although not shown, holes generated in the photoconductive film 2 of FIG. 1 may be accumulated in the storage capacitor C _ST . It serves as a collecting electrode to collect charges.

In addition, holes stored in the storage capacitor C _ST move to the source electrode 112 through the drain electrode 114, and are processed in an external circuit (not shown) via the data wires 116 and 118 to be represented as an image. do.

In the above-described configuration, the characteristic is that unlike the prior art, one data line is cut at the center of the substrate 100 and spaced apart, and the data integrated circuits are formed on both sides of the cut data line, respectively. The data signals are applied to the data lines 116 and 118, respectively.

This will be described below with reference to FIG. 5.

5 is a plan view schematically illustrating a configuration of an image sensing device according to the present invention.

As illustrated, the image sensing device 99 may be defined as a display area A and a driving area D1, D2, and D3 representing an image, and the display area A is illustrated in FIG. 4 as described above. As described above, a switching element, a photoconductive film, and the like are formed in each of the gate wirings, the data wirings, and each pixel region.

In addition, a gate driving region D3 is formed around the display region A, that is, on one side of the image device, and the first data driving region D1 and the second data driving region are respectively formed on two sides that are not parallel thereto. D2) is configured.

The first data driving region D1 is configured on one side of the first data wiring 118 of FIG. 4, and the second data driving region D2 is spaced apart from the first data wiring 118 of FIG. 4. The other side of the second data line 116 is arranged side by side.

A data integrated circuit is configured in the data driving regions D1 and D2, and a gate integrated circuit is configured in the gate driving region D3.

Such a configuration has a merit that a problem of deterioration of image quality due to signal delay can be solved because a signal is applied with a length of 1/2 than the conventional one.

Hereinafter, a method of manufacturing DXD according to the present invention will be described with reference to FIGS. 6A to 6F.

6A to 6F are cross-sectional views of the VV of FIG. 4 taken along the process sequence.

As shown in FIG. 6A, one or more selected from among low-resistance aluminum (Al), aluminum alloy (mainly AlNd), molybdenum (Mo), chromium (Cr), and tungsten (W) on the substrate 100. The material is deposited and patterned to form a plurality of gate electrodes 102 and a plurality of gate wirings 104 in contact therewith.

The reason for using each of the components as a double metal layer is that as the gate electrode 102 material, aluminum has a low resistance in order to reduce the RC delay, but pure aluminum has a weak chemical corrosion resistance, and Since a wiring defect problem is caused by the formation of hillock in a high temperature process, the laminated structure is applied as described above.

Next, an inorganic insulating material group including a silicon nitride film (SiN _X ) and a silicon oxide film (SiO ₂ ) on an entire surface of the substrate 100 on which the gate electrode 102 and the gate wiring (104 in FIG. 4) are formed; In some cases, the gate insulating layer 106 may be formed to have a thickness of 100 kV to 3000 kV by depositing or applying one selected from the group of organic insulating materials including benzocyclobutene (BCB), acryl resin, and the like.

As shown in FIG. 6B, on the gate insulating film 106, pure amorphous silicon (A-Si: H) and impurity amorphous silicon (n + a-Si) in a state where the insulating film is not exposed to the outside air. : H) is laminated in order and patterned to form active layer 108 and ohmic contact layer 110.

Next, one or more materials selected from the group consisting of molybdenum (Mo), chromium (Cr), and tungsten (W) are deposited on the entire surface of the substrate 100 on which the active layer 108 and the ohmic contact layer 110 are formed. Thus, a source electrode 112 and a drain electrode 114 spaced apart from each other on the ohmic contact layer are formed, and contact with the source electrode 112 perpendicularly cross the gate wiring (104 in FIG. 4). As a result, the first data line 116 and the second data line 118 defining the pixel region P are formed.

The first data line 116 and the second data line 118 are configured to be parallel to each other in one direction, and are formed to be spaced apart from each other at a central portion of the substrate 100.

Accordingly, the first data line 116 and the second data line 118 are each formed to have a length of about 1/2 or less than that of a general data line.

The source and drain electrodes 112 and 114 and the data line 118 are formed, and at the same time, the ground line 120 that crosses the center of the pixel region P is formed.

Subsequently, using the source and drain electrodes 112 and 114 as an etching mask, a process of removing the ohmic contact layer 110 exposed at a lower portion thereof is performed to expose the active layer 108 at the lower portion thereof. do.

The exposed active layer 108 functions as an active channel through which electrons or holes flow.

As shown in FIG. 6C, silicon nitride (SiN _X ) and silicon oxide (SiO ₂ ) are formed on the entire surface of the substrate 100 on which the source and drain electrodes 112 and 114, the data lines 116 and 118, and the ground line 120 are formed. The first passivation layer 122 is formed by depositing one or more materials selected from the group of inorganic insulating materials including a.

When the first passivation layer 122, which is a layer in direct contact with the exposed active layer 108, is formed of a silicon insulating layer, electrons are transferred because the interface property between the exposed active layer 108 and the first passivation layer 122 is excellent. The area to be trapped becomes smaller, and therefore, the result is that the mobility of electrons becomes faster.

Next, the first passivation layer 122 corresponding to a part of the ground line 120 passing through the pixel region P is etched to form a ground line contact hole 124 exposing the lower ground line 120. .                     

Next, as shown in FIG. 6D, a transparent conductive metal including indium tin oxide (ITO) and indium zinc oxide (IZO) on the entire surface of the substrate 100 on which the first passivation layer 124 is formed. A selected one of the group is deposited and patterned to form a capacitor electrode 126 configured in the pixel region P while contacting the ground line 120.

The ground line 120 is formed to pass through a portion of the pixel region P (FIG. 4), but the capacitor electrode 126 is wider than the ground line 120 unless it overlaps with the data lines 116 and 118. As a result, it is formed to overlap at least half of the total area of the pixel electrode (formed in a later process).

As shown in FIG. 6E, one of the above-described inorganic insulating material groups is deposited on the entire surface of the substrate 100 on which the capacitor electrode 126 is formed to form the second passivation layer 130.

The second passivation layer 130 is patterned to form a drain contact hole 132 exposing the drain electrode 114.

Next, as shown in FIG. 6F, a transparent conductive metal including indium tin oxide (ITO) and indium zinc oxide (IZO) on the entire surface of the substrate 100 on which the second passivation layer 130 is formed. A selected one of the group of materials is deposited and patterned to form a pixel electrode 134 formed in the pixel region P while contacting the drain electrode 114 partially exposed.

In the above-described configuration, the X-ray image sensing device can be manufactured by configuring the photoconductive film, the protective film, the high voltage electrode, the high voltage DC power supply, and the like as described above with reference to FIG. 1.

The photoconductive film is formed of a material selected from the group consisting of amorphous selenium, HgI ₂ , PbO, CdTe, CdSe, thallium bromide, and cadmium sulfide.

As described above, the X-ray image sensing device formed by the fabrication method according to the present invention independently forms a data integrated circuit on each data wiring divided into 1/2 lengths, unlike the conventional art, when forming the data wiring. In addition, the length of the wiring through which the video signal flows is shortened, thereby preventing the signal delay.

In addition, it is possible to obtain a clear image by preventing signal delay.

Claims (8)

A plurality of gate wirings formed in one direction on the substrate; A first data line and a second data line defined to cross the gate line vertically with a gate insulating layer interposed therebetween to define a pixel area, and separated from one another in a central direction of the substrate; A switching element configured at a point where the first and second data lines and the gate line cross each other; A ground line formed in one direction in the pixel area; A first passivation layer formed on a front surface of the substrate on which the switching element and the ground wiring are formed and patterned to expose a part of the ground wiring; A capacitor electrode in contact with the exposed ground line; A second passivation layer formed on a front surface of the substrate including the capacitor electrode and patterned to expose a portion of the switching element; A pixel electrode in contact with the exposed switching element; X-ray image sensing device comprising a. The method of claim 1, And a data driving circuit at one end of the first data line and at one end of the second data line, and a gate driving circuit at one end of the gate line. The method of claim 1, And a storage capacitor having a capacitor electrode in contact with the ground wiring as a first electrode and a pixel electrode thereon as a second electrode. The method of claim 1, The switching device is a thin film transistor comprising a gate electrode, an active layer (and ohmic contact layer), a source electrode and a drain electrode. Defining a display area on the substrate and a drive area around the display area; Forming a gate wiring in one direction corresponding to the display area; Forming a pixel area by vertically intersecting the gate line with a gate insulating layer interposed therebetween, and forming a first data line and a second data line spaced apart in one direction from a center area of the substrate; Forming a switching element at a point where the first and second data lines and the gate line cross each other; Forming a ground line formed in one direction in the pixel area; Forming a first passivation layer formed on an entire surface of the substrate on which the switching element and the ground line are formed, and wherein the first passivation layer is patterned to expose a part of the ground line; Forming a capacitor electrode in contact with the exposed ground line; Forming a second passivation layer formed on a front surface of the substrate on which the capacitor electrode is formed and patterned to expose a portion of the switching element; Forming a pixel electrode in contact with the exposed switching element; X-ray image sensing device manufacturing method comprising a. The method of claim 5, And a data driving circuit at one end of the first data line and at one end of the second data line, and a gate driving circuit at one end of the gate line. The method of claim 5, Forming a photoconductive film on the pixel electrode; And forming a conductive electrode on the photoconductive film. The method of claim 7, wherein The photoconductive film is a material selected from the group consisting of amorphous selenium (selenium), HgI ₂ , PbO, CdTe, CdSe, thallium bromide, cadmium sulfide.

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