KR20010094907A - X-ray detecter and a method for fabricating the same - Google Patents

Abstract

PURPOSE: An X-ray detector and a method for fabricating the same are provided to prevent a damage of an array panel due to static electricity using a TFT(Thin Film Transistor) array process. CONSTITUTION: A multitude of gate line(110) is formed on an edge portion of a TFT array area(104). Gate pads(112) are formed on each end portion of the gate lines(110). A gate extension portion(114) is extended from the gate pad(112). The gate extension portion(114) is short-circuited by a short-circuit line(108). The short-circuit line(108) is formed by the same metal as the gate line(110). The short-circuit line(108) and the gate line(110) are formed simultaneously. An array outline portion(102) is formed at an outline of the short-circuit line(108). A connection line(106) is formed between the short-circuit line(108) and the array outline portion(102). The connection line(106) is contacted simultaneously with the short-circuit line(108) and the array outline portion(102).

Description

X-ray detector and its manufacturing method {X-ray detecter and a method for fabricating the same}

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

Diagnostic X-ray (X-ray) test method, which is widely used for medical purposes today, is photographed using an X-ray detection film, and a predetermined film print time has to be passed 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 a merit of diagnosing a result in real time immediately after imaging of 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.

1 is a schematic diagram illustrating the configuration and operation of the X-ray image sensing device 100, in which a substrate 1 is formed below the thin film transistor 3, the storage capacitor 10, the pixel electrode 12, and the luminous intensity. It consists of the front film 2, the protective film 20, the electrode 24, the high voltage | voltage DC power supply 26, etc.

The photoconductive film 2 forms an electrical signal, that is, electron and hole pair 6, internally in proportion to the signal intensity of an external electric wave or magnetic wave incident thereto. 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 formed under the photoconductive film 2 by the voltage Ev applied from the high voltage DC power supply 26 to the conductive electrode 24 positioned on the photoconductive film 2. Collected in the form of a charge on the pixel electrode 12 is located, and stored in the storage capacitor 10 formed with a common electrode grounded from the outside. At this time, the charge stored in the storage capacitor 10 is sent to the external image processing element by the thin film transistor 3 to control the external to produce an X-ray image.

However, in order to detect even the weak X-ray light and convert it into a charge in the X-ray image sensing device, the number of trap state densities trapping the charge in the photoconductive film 2 is reduced, and the conductive electrode 24 and the pixel electrode 12 are separated. Apply a large vertical voltage (10V / μm or more) to reduce the current flowing by voltages other than the vertical direction.

Charges in the photoconductive film 2 generated by the X-ray light are trapped and collected not only on the pixel electrode but also on the protective film that protects the channel portion of the thin film transistor 3. The trapped electric charges thus induce charge in the channel region above the thin film transistor 3 to generate a large leakage current even when the thin film transistor 3 is in an off state, thereby preventing the thin film transistor 3 from performing a switching operation.

In addition, the electrical signal stored in the storage capacitor 10 may flow to the outside due to a large leakage current in the off state, a phenomenon may not be properly represented to obtain the image.

2 is a plan view showing one pixel portion of a general X-ray detector, in which the gate wirings 30 are arranged in the row direction, and the data wirings 40 are arranged in the column direction. In addition, the thin film transistor 3 is formed as a switching element having the gate electrode 32, the source electrode 42, and the drain electrode 44 at a portion where the gate wiring 30 and the data wiring 40 are perpendicular to each other. The ground wiring 52 is arranged as a common electrode which is commonly grounded with adjacent pixels adjacent to each other in the direction.

In the pixel portion, the first and second capacitor electrodes 46 and 47 are insulated from each other by a dielectric material (not shown) with a transparent electrode, and the first capacitor electrode 46 is formed on the ground line 52. Is in electrical contact with

That is, a storage capacitor having first and second capacitor electrodes 46 and 47 and a pixel electrode 56 as charge storage means is formed, and a silicon nitride film (not shown) is formed of a dielectric material.

Here, the pixel electrode 56 extends to the upper portion of the thin film transistor 3, and although not shown, the pixel electrode 56 collects electric charges so that holes generated in the photoconductive film can accumulate in the storage capacitor P. Play a role.

In addition, the pixel electrode 56 may be electrically connected to the drain electrode 44 through the drain contact hole 50 so that holes stored in the storage capacitor may be coupled with electrons introduced through the thin film transistor 3. It is connected.

In addition, a gate pad 34 is formed at one end of the gate line 30 and a data pad 41a is formed at one end of the data line 40.

The data pad 41a is formed with a data pad link portion 41b in contact with the data line 40, and the data pad link portion 41b is connected to the data line 40 through a data link contact hole 43a. ) And the data pad 41a are connected.

Here, the data pad 41a uses the same metal as the gate wire 30 and is formed at the same time. The reason for using the data pad 41a as the same metal as the gate wiring 30 as described above is to improve contact between the wire and each pad in a wire bonding process for connecting the driving circuit later. As the metal used as the gate wiring 30, a double structure such as aluminum and molybdenum is mainly used.

The function of the above-described X-ray detector is summarized as follows.

Holes generated from the photoconductive film (not shown) are collected in the pixel electrode 56 and stored in the storage capacitor configured together with the first and second capacitor electrodes 46 and 47.

In addition, the holes stored in the storage capacitor are moved to the source electrode 42 through the drain electrode 44 and the pixel electrode 56 by the operation of the thin film transistor 3, and from the external circuit (not shown) to the image Express.

In this case, charges that do not completely escape to the outside through the external circuit, that is, residual charge remaining in the storage capacitor, are completely removed through the ground wiring 52 by an external circuit.

As shown in FIGS. 3A to 3F, the manufacturing process of the X-ray image sensing device will be described according to the section taken along the cutting line III-III of FIG. 2.

First, referring to FIG. 3A, a low-resistance metal such as aluminum (Al) or an aluminum alloy (preferably Mo / Al) is deposited and patterned as a first metal on the substrate 1 to form the gate electrode 32. And a data pad 41.

Here, the gate electrode 32 and the data pad 41 are formed independently. The reason why the data pad 41 is simultaneously formed when the gate electrode 32 is formed is to improve the performance of the bonding process by wires in the mounting process of the driving circuit. That is, aluminum (Al) included in the first metal is a metal that is well bonded in the wire bonding process.

The data pad 41 is substantially divided into two parts, one of which consists of a data pad electrode 41a in contact with a wire and a data link part 41b in contact with a data line to be formed in a later process.

The substrate 1 includes an expensive quartz plate having a high melting point of an insulating material and a glass substrate mainly used in a low temperature process.

3B illustrates forming a gate insulating film 60 and an active layer 65 on the patterned first metal, and patterning a gate insulating film covering the data link portion 41b to form a data link hole 43a. Figure is a diagram.

As the gate insulating layer 60, a silicon nitride film (SiN _x ) is mainly used, and the active layer 65 has a stacked structure of pure amorphous silicon 62 and impurity amorphous silicon 64.

After the active layer 65 is formed, a portion of the gate insulating layer 65 covering the data link portion 41b of the data pad 41 is patterned so that a portion of the data link portion 41b is exposed. The hole 43a is formed. The reason for forming the data link hole 43a is for contact between the data line to be formed in a later process and the data pad 41.

3C is a diagram illustrating a step of forming the first capacitor electrode 46 and the data line 40.

The first capacitor electrode 46 functions as the first electrode of the storage capacitor that stores the charge. The first capacitor electrode 46 is formed of ITO, which is a substantially transparent conductive material, and forms a drain auxiliary electrode 48 at a portion where the drain electrode is to be formed when the first storage capacitor is formed.

The drain auxiliary electrode 48 functions as a medium for connecting the pixel electrode and the drain electrode to be formed in a later process.

After forming the first capacitor electrode 46 and the drain auxiliary electrode 48, the source and drain electrodes 42 and 44 and the data line 40 are formed of a second metal.

The data line 40 comes into contact with the data link part 41b through the data link hole 43a and is substantially in contact with the data pad electrode 41a.

The source electrode 42 is in contact with the data line 40, and the drain electrode 44 is formed to overlap a portion of the drain auxiliary electrode 48.

In addition, a ground wiring 52 is formed on the first capacitor electrode 46 with the second metal.

FIG. 3D illustrates depositing a dielectric layer 66 and ITO over the entire substrate, and patterning the ITO to form a second capacitor electrode 47.

The dielectric layer 66 uses the same silicon nitride film as the gate insulating film 60.

The second capacitor electrode 47 functions as an etch stop layer that prevents overetching of the dielectric layer 66 by a later process, and functions as an electrode of the storage capacitor.

FIG. 3E illustrates a step of forming the passivation layer 68 and the pixel electrode 56 over the second capacitor electrode 47 and the entire surface of the substrate.

BCB (benzocyclobutene) having a low dielectric constant is used as the passivation layer 68, and a drain contact hole in which a part of the drain auxiliary electrode 48 and the second capacitor electrode 47 are partially exposed to the drain electrode 44 is exposed. 50 and a capacitor contact hole 54 are formed.

In this case, in order to form the drain contact hole 50, the passivation layer 68 and the dielectric layer 66 are simultaneously etched. Accordingly, the second capacitor electrode 47 performs a function of preventing the dielectric layer of the storage capacitor from being overetched.

Meanwhile, the passivation layer 68 and the dielectric layer 60 on the data pad part 41 are also simultaneously etched.

Thereafter, a transparent conductive material (ie, ITO) is deposited and patterned on the passivation layer to form the pixel electrode 56.

The pixel electrode 56 contacts the drain auxiliary electrode 48 and the second capacitor electrode 47 exposed through the drain contact hole 50 and the capacitor contact hole 54, respectively.

The reason why the drain auxiliary electrode 48 is formed to contact the drain electrode 44 and the pixel electrode 56 is that the contact resistance is reduced because the pixel electrode 56 and the drain auxiliary electrode 48 are made of the same material. Because.

FIG. 3F illustrates a step of finally exposing the data pad electrode 41a. The molybdenum layer positioned on the upper portion of the laminated structure of the gate insulating layer 60 and molybdenum / aluminum on the data pad electrode 41a is shown. Etch at the same time.

The reason for etching molybdenum and leaving only aluminum in the data pad electrode 41a is to smoothly bond between the wire and the data pad electrode 41a in the process of mounting the driving circuit.

Although the following process is not shown, the photosensitive material is applied to the photosensitive material. The photosensitive material is used as a transducer for receiving an external signal and converting the signal into an electrical signal. The compound of amorphous selenium is converted into a vacuum using an evaporator. Deposit at -500 μm thickness. In addition, an X-ray photosensitive material having a low dark conductivity and sensitive to an external signal, particularly X-ray photoconductor, may be used, such as HgI ₂ , PbO, CdTe, CdSe, thallium bromide, cadmium sulfide, and the like. When X-ray light is exposed to the photosensitive material, electron and hole pairs are generated in the photosensitive material according to the intensity of the exposed light.

After applying the X-ray photosensitive material, a transparent conductive electrode may be formed to transmit X-ray light.

The function of each component of the above-described X-ray image sensing device is as follows.

First, the photosensitive conductive layer and the conductive electrode which generate charge by sensing external X-ray light function as a photoelectric conversion part. Second, the storage capacitor which stores the charge generated in the photoelectric conversion part is a charge storage part. It will function as. Third, the thin film transistor which transfers the charge stored in the charge storage unit to an external driving circuit functions as a switching unit.

As described above, the TFT array panel of the conventional X-ray detector is completed through about nine photolithography processes and about seven plasma deposition processes.

In the plasma deposition process, a material layer (gate material, active layer, first and second capacitor electrodes, etc.) is formed in a state where a plurality of ions are present, and thus a probability of generating static electricity in the panel in the process of manufacturing an array panel This becomes very loud.

In other words, since the substrate used for fabricating the array panel uses glass as an insulator, static electricity or arc discharge generated during the fabrication process of the array panel flows into the array panel and is present locally. . Such static electricity can cause fatal damage to the switching elements of the array panel because of the very high voltage.

As described above, in the related art, an antistatic structure is designed on the panel to remove static electricity generated in the process of manufacturing the panel, thereby preventing defects.

4A to 4B are diagrams illustrating a conventional circuit of an array panel that prevents static electricity. In FIG. 4A, the gate lines G and the data lines D are connected to each other by a short circuit 70, respectively. Wiring (gate and data wiring) is engaged with the antistatic element 72.

Meanwhile, in order to prevent static electricity, in FIG. 4B, the gate wiring G and the data wiring D are connected by a short circuit 70, and each of the short circuits 70 is an antistatic device ESD and a resistor 72, 74. Is connected to.

However, in the above-described array panel having the conventional antistatic circuit, the antistatic circuit starts operation after the antistatic circuit and the resistor are formed, and before that (before the formation of the antistatic circuit and the resistor). There is no countermeasure against static electricity. That is, the antistatic circuit or the resistor is formed after the ITO process, and the process performed before the ITO process becomes unprotected from static electricity or arc discharge.

In addition, even if short-circuit wiring is formed in contact with each wiring, since the outer portion of the substrate is a complete insulator, no static or arc discharge generated in the interior of the array substrate has any flow path to the outside. As a result, static electricity, arc discharge, and the like will cause great damage to the array substrate.

In particular, the static electricity or arc discharge is generated a lot in the BCB process used as a protective film, which is due to the plasma (Plasma) process to apply BCB in the protective film process and improve the hardness or stability.

Therefore, there is a disadvantage in that the panel may be damaged by the breakdown of the functional thin film such as the insulating layer or the semiconductor layer by the static electricity generated before the generation of the antistatic circuit.

In order to solve the above problems, an object of the present invention is to prevent damage to the array panel by static electricity generated before the formation of the antistatic circuit.

1 is a cross-sectional view showing the operation of the X-ray image sensing device.

2 is a cross-sectional view showing a cross section corresponding to one pixel portion of a conventional X-ray image sensing device.

3A to 3F are process diagrams illustrating a fabrication process of a cross section taken along the cutting line III-III of FIG. 2.

4A and 4B illustrate a circuit of a conventional X-ray detector in which an antistatic circuit is formed.

5 shows a schematic plane of an x-ray detector according to the invention.

FIG. 6 is an enlarged view of a portion Z of FIG. 5; FIG.

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6. FIG.

8 is a view showing a cross section when the final process in FIG.

<Explanation of symbols for main parts of drawing>

100: x-ray detector panel 102: the outer edge of the array

104: TFT array region 106: connection wiring

108: short circuit wiring 110: gate wiring

112: gate pad

In order to achieve the above object, the present invention provides a substrate comprising: a substrate defining a first region and a second region surrounding the first region and in contact with an edge thereof; A plurality of X-ray sensing elements positioned in a first area of the substrate and sensing X-ray light; A plurality of first signal wires positioned in the first area and connected to the X-ray sensing element and extending in a first direction; A plurality of second signal wires positioned in the first area and crossing the first signal wires and extending in a second direction; First and second short-circuit wirings disposed in the first region and connecting ends of the first signal wiring and the second signal wiring; A ground portion formed along an edge of the second region of the substrate; An X-ray detector array substrate is disposed in a second region of the substrate and includes first and second connection wires connecting the ground portion and the first and second short circuit lines, respectively.

In addition, the present invention comprises the steps of providing a substrate; Forming a plurality of first signal wires on the substrate; Forming a plurality of second signal wires intersecting the first signal wires; Forming a plurality of X-ray sensing elements connected to the first and second signal wires, respectively; Forming first and second short circuit lines connected to the first and second signal lines, respectively; Forming first and second connection wires connected to the first and second short circuit lines, and a ground part connected to the first and second connection wires and formed along an edge of the substrate; Forming a protective film over the first and second connection wirings and the entire surface of the substrate; Etching a portion of the passivation layer to expose the first and second connection wires; A method of manufacturing an X-ray detector array substrate including etching the exposed first and second connection wires is provided.

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

FIG. 5 is a view schematically showing a plane of the X-ray detector panel 100 according to the present invention. In the present invention, a thin film transistor array region (TFT array) 104 is substantially used in the panel of the X-ray detector. The panel of the X-ray detector is manufactured by dividing the area to be formed into an array outer portion 102 spaced apart by a predetermined interval along the edge of the TFT array region 104.

Meanwhile, the TFT array region 104 and the array outer portion 102 are connected by a connecting portion 106.

Here, the array outer portion 102 is formed to protect the TFT array region 104 from arc discharge or static electricity that may occur during fabrication of the X-ray detector panel 100 in the TFT array region 104.

The connecting portion 106 is a flow path of static electricity that moves the arc discharge or static electricity generated in the TFT array region 104 to the outer edge portion of the array 102.

The connecting portion 106 and the array outer portion are etched or cut after completion of the TFT array region to follow a general X-ray detector manufacturing process.

FIG. 6 is an enlarged view of a portion Z of FIG. 5, and a plurality of gate lines 110 and gate pads 112 are formed at ends of each of the gate lines at horizontal edges of the TFT array region 104.

In addition, the gate extensions 114 extending from the respective gate pads 112 are shorted to each other by a short circuit line 108.

Preferably, the short wiring 108 is used as the same metal as the gate wiring 110, and is formed in the same process. In other words, the gate wiring 110 is formed at the same time.

An array outer portion 102 is formed outside the short circuit wiring 108, and a connection wiring 106 that contacts the array outer portion 102 and the short circuit wiring 108 at the same time is connected to the short circuit wiring 108. It is formed between the array outer portion (102).

As described above, in the method of manufacturing the panel 100 of the X-ray detector according to the present invention, since the array outer portion 102 serving as the ground is formed from the process of forming the gate wiring, the arc generated before the formation of the antistatic circuit and the resistor. The discharge or static electricity can be effectively removed.

That is, when fabricating a TFT array substrate, the portion where metal is used is a process of forming gate components (gate wiring, gate electrode, gate pad, etc.) and data components (data wiring, source electrode, drain electrode, etc.), The metal layer is damaged due to tearing or melting of the metal layer around the edge of the panel due to static electricity and arc discharge generated during the manufacturing process.

In order to prevent the above problems, in the present invention, as illustrated in FIG. 6, the array outer portion 102 and the TFT array region 104 are formed therein, and are connected therebetween.

By connecting the array outer portion 102 and the TFT array region 104 as described above, the array region 104 and the array outer portion 102 are formed with an equipotential, thereby preventing static electricity or arc discharge generated during the manufacturing process of the panel. The damage to the panel can be reduced by discharging to the array outer portion 102.

The connection wiring 106 functioning as described above is etched later in the process of forming the contact hole of the gate and the data pad. After the TFT array substrate is completed, if the gate component and the data component are shorted, the IPT ( In-Processing Test). For this reason, the completed TFT array area and the outer edge of the array must be made electrically independent of each other. In addition, the outer edge of the array is later cut by a laser or other cutting means.

Here, the connection wiring 106 that contacts the array outer portion 102 and the short circuit wiring 108 of the TFT array region 104 may be a gate metal or a data metal. That is, the connection wiring 106 is formed at the same time when forming the gate or data component, and when the connection wiring 106 is formed simultaneously with the gate component, the connection wiring 106 is formed on the same layer as the short circuit wiring 108. When formed simultaneously with the component, a contact hole for exposing the short circuit 108 is formed in a hole forming process (see FIGS. 3B and 3C) of the data pad link portion, and the exposed short circuit 108 is formed at the same time as the formation of the data component. ) And the connection wiring 106 come into contact with each other.

FIG. 7 is a cross-sectional view taken along the cutting line VII-VII of FIG. 6, and illustrates a manufacturing process of the conventional X-ray detector when the connection line 106 is simultaneously formed with the data component. Figure is a diagram.

In the drawings, the same reference numerals are given to components having the same functions as in the prior art.

First, a brief description of the drawing shown in FIG. 7 includes forming a gate component (ie, a gate short circuit 108 and a gate extension 114 connected thereto) on the substrate 1. The gate insulating film 60 is formed on the entire surface of the substrate 1 in a covering form.

Meanwhile, a short circuit contact hole 108a through which a portion of the short circuit 108 is exposed is formed in the short circuit upper gate insulating layer 60, and the short circuit contact hole 108a is simultaneously formed in the process of FIG. 3B. do. In other words, the data link hole 43a is formed at the same time.

On the gate insulating layer 60 on which the short circuit contact hole 108a is formed, a connection wiring 60 extends from the outer edge of the array 102 and the short circuit wiring 108 exposed through the short circuit contact hole 108a. Contact.

The short circuit 108 and the array outer portion 102 are formed in a data component, that is, the process of FIG. 3C.

In addition, a dielectric layer 66 and a passivation layer 68 are formed on the front surface of the data component and the substrate 1 while exposing the connection line 106. Such a structure is formed in a process subsequent to FIG. 3E.

As described above, in the structure of the X-ray detector panel according to the present invention, since the TFT array portion and the array outer portion are interconnected through the connection wiring 106 in the process after FIG. 3B of the conventional X-ray detector manufacturing process, the equipotential is formed, It is possible to prevent the panel from being damaged by static electricity or arc discharge by a later process.

Meanwhile, FIG. 8 is a view illustrating a result of etching the connection wiring 106 for the IPT test after completing the TFT array panel, which is shown after the process of FIG. 3F of the conventional X-ray detector manufacturing process.

That is, the present invention has the advantage of effectively reducing the damage of the panel due to static electricity or arc discharge in the same manner as the conventional manufacturing process of the X-ray detector without additional process.

As described above, in the present invention, although the central idea of the present invention has been described with respect to the X-ray detector, the present invention may be applied to a thin film transistor array substrate like a liquid crystal display.

The X-ray detector according to the embodiment of the present invention has an increased production yield because an electrostatic protection device for static electricity and arc discharge is formed in the initial fabrication process of the TFT array substrate without the additional process compared to the conventional X-ray detector manufacturing process. It has the advantage of being.

Claims (5)

A substrate defining a first region and a second region surrounding the first region and in contact with an edge thereof; A plurality of X-ray sensing elements positioned in a first area of the substrate and sensing X-ray light; A plurality of first signal wires positioned in the first area and connected to the X-ray sensing element and extending in a first direction; A plurality of second signal wires positioned in the first area and crossing the first signal wires and extending in a second direction; First and second short-circuit wirings disposed in the first region and connecting ends of the first signal wiring and the second signal wiring; A ground portion formed along an edge of the second region of the substrate; First and second connection wires positioned in a second area of the substrate and connecting the ground portion and the first and second short circuit lines, respectively; X-ray detector array substrate comprising a. The method according to claim 1, The X-ray detector array substrate of the ground portion is the same material as the second signal wiring. The method according to claim 1, The first and second connection wirings extend integrally from the ground portion. Providing a substrate; Forming a plurality of first signal wires on the substrate; Forming a plurality of second signal wires intersecting the first signal wires; Forming a plurality of X-ray sensing elements connected to the first and second signal wires, respectively; Forming first and second short circuit lines connected to the first and second signal lines, respectively; Forming first and second connection wires connected to the first and second short circuit lines, and a ground part connected to the first and second connection wires and formed along an edge of the substrate; Forming a protective film over the first and second connection wirings and the entire surface of the substrate; Etching a portion of the passivation layer to expose the first and second connection wires; Etching the exposed first and second connection wires X-ray detector array substrate manufacturing method comprising a. The method according to claim 4, The first and second connection wirings are integrated with the ground unit.