KR101034474B1 - X-ray detector and method for manufacturing the x-ray detector - Google Patents

Abstract

In the X-ray detector and its manufacturing method capable of increasing the fill factor, the X-ray detector is formed of gate and data wires formed to cross each other on the substrate and electrically connected to the gate and data wires respectively formed on the substrate. A thin film transistor, a photoconductive semiconductor formed on the lower electrode portion and the lower electrode portion electrically connected to the drain electrode to cover the drain electrode of the thin film transistor and disposed on the lower electrode portion, and a transparent conductive material formed on the photoconversion semiconductor. PIN diode comprising an upper electrode portion consisting of: a diode protection film having a bias contact hole formed to cover the PIN diode and exposing a portion of the upper portion of the PIN diode, the upper portion of the PIN diode being formed on the diode protection film and through the bias contact hole; Electrical contact And an optical wavelength converter configured to convert the X-rays disposed on the earth wiring and the diode protective layer and applied from the outside into wavelengths absorbed by the PIN diode. As such, a lower electrode part made of a transparent conductive material may be formed on the drain electrode to increase the fill factor.

Lower electrode

Description

X-ray detector and its manufacturing method {X-RAY DETECTOR AND METHOD FOR MANUFACTURING THE X-RAY DETECTOR}

The present invention relates to an X-ray detector and a method for manufacturing the same, and more particularly, to an X-ray detector and a method for manufacturing the same that can detect the X-rays and the inside of the object.

In general, X-rays have a short wavelength and can easily penetrate an object. The amount of X-rays transmitted is determined by the degree of compactness inside the object. That is, the internal state of the object may be indirectly observed through the transmission amount of the X-ray that has passed through the object.

The X-ray detector is a device that detects the amount of transmission of the X-ray that has passed through the object. The X-ray detector may detect the transmission amount of the X-ray and display the internal state of the object to the outside through a display device. The X-ray detector may generally be used as a medical inspection device, a non-destructive inspection device, and the like.

The X-ray detector generally includes an optical wavelength converter that converts X-rays applied from the outside into visible light, a PIN diode that converts the visible light into electricity, and a thin film transistor electrically connected to the PIN diode. In this case, the PIN diode is formed so as not to overlap the thin film transistor.

However, as the PIN diode is formed so as not to overlap with the thin film transistor, the area of the PIN diode is reduced, and as a result, the area capable of receiving the X-ray is reduced, that is, the fill factor is reduced. There is a problem.

Accordingly, the present invention is to solve this problem, the problem to be solved by the present invention is to provide an X-ray detector that can increase the fill factor for the X-ray incident from the outside.

In addition, another object of the present invention is to provide a manufacturing method capable of manufacturing the X-ray detector.

The X-ray detector according to the exemplary embodiment of the present invention includes a gate wiring, a data wiring, a thin film transistor, a PIN diode, a diode protective film, a biaser wiring, and an optical wavelength converter.

The gate and data lines are formed to cross each other on a substrate, and the thin film transistor is formed on the substrate and electrically connected to the gate and data lines, respectively. The PIN diode is formed on the drain electrode to cover the drain electrode of the thin film transistor and is electrically connected to the drain electrode, an optical conversion semiconductor disposed on the lower electrode part, and the photoconversion semiconductor image. And an upper electrode portion formed on the transparent conductive material. The diode protection layer is formed to cover the PIN diode and has a bias contact hole exposing a portion of the upper portion of the PIN diode. The bias wiring is formed on the diode protection layer and is in electrical contact with the upper portion of the PIN diode through the bias contact hole. The optical wavelength converter is disposed on the diode protection layer, and converts an X-ray applied from the outside into a wavelength absorbed by the PIN diode.

The lower electrode portion may be formed on the substrate to cover the drain electrode, and may be electrically connected to the drain electrode in direct contact with the drain electrode. Alternatively, a passivation layer may be further formed under the lower electrode to cover and protect the thin film transistor and to expose a portion of the drain electrode. In this case, the lower electrode portion may be formed on the passivation layer to cover the drain electrode, and may be electrically connected to the drain electrode through the drain contact hole.

The lower electrode part may be made of a conductive material having a lower resistance than the drain electrode. The lower electrode part may be made of indium tin oxide (ITO), which is a transparent conductive material.

Meanwhile, an outer passivation layer formed on the diode passivation layer may be further formed under the optical wavelength converter to cover the bias wiring. Here, the light wavelength converter may be attached to the outer protective film in the form of a film, but may be deposited on the outer protective film.

The bias wiring may include a transparent wiring portion formed on the diode protection layer and in electrical contact with an upper portion of the PIN diode through the bias contact hole, and formed of a transparent conductive material, and a metal wiring portion formed on the transparent wiring portion. have.

The light blocking unit may be formed on the thin film transistor to cover the thin film transistor. The light blocking unit may cover a portion of the thin film transistor so as not to overlap the PIN diode.

In the method of manufacturing an X-ray detector according to an exemplary embodiment of the present invention, first, gate and data lines crossing each other and a thin film transistor electrically connected to the gate and data lines are respectively formed on a substrate. Subsequently, a lower electrode portion disposed on the drain electrode and electrically connected to the drain electrode to cover the drain electrode of the thin film transistor, an optical conversion semiconductor disposed on the lower electrode portion, and an optical conversion semiconductor. And a top electrode part made of a transparent conductive material. Subsequently, a diode protection layer is formed to cover the PIN diode and have a bias contact hole exposing a portion of the upper portion of the PIN diode. Subsequently, a bias wire in electrical contact with the upper portion of the PIN diode through the bias contact hole is formed on the diode protection layer. Subsequently, an optical wavelength conversion unit for converting an X-ray applied from the outside into a wavelength absorbed by the PIN diode is disposed on the diode protection layer.

The forming of the PIN diode may include forming a lower electrode part covering the drain electrode to be in direct electrical contact with the drain electrode.

Alternatively, the method of manufacturing the X-ray detector may further include forming a passivation layer having a drain contact hole covering and protecting the thin film transistor and exposing a portion of the drain electrode before forming the PIN diode. . In this case, the forming of the PIN diode may include forming the lower electrode part on the passivation layer covering the drain electrode and electrically connected to the drain electrode through the drain contact hole.

The lower electrode part may be made of indium tin oxide (ITO), which is a transparent conductive material.

As described above, according to the X-ray detector and a method of manufacturing the same, the lower electrode part made of a transparent conductive material may be formed on the upper portion of the drain electrode to increase the fill factor. That is, as the lower electrode portion is formed on the drain electrode, the area of the PIN diode that can receive X-rays can be increased.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text.

However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and that one or more other features It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, actions, components, parts or combinations thereof.

In the drawings, the thickness of each device or film (layer) and regions has been exaggerated for clarity of the invention, and each device may have a variety of additional devices not described herein. When (layers) are referred to as being located on other films (layers) or substrates, they may be formed directly on other films (layers) or substrates or additional films (layers) may be interposed therebetween.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

≪ Example 1 >

1 is a plan view showing a part of the X-ray detector according to the first embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line II 'of FIG.

1 and 2, the X-ray detector according to the present exemplary embodiment may include a base substrate 100, a gate wiring 110, a gate insulating film 120, a data wiring 130, a thin film transistor (TFT), and a PIN diode ( DI), the diode protection film 150, the bias wiring 160, the light blocking part 170, the outer protection film 180, and the light wavelength converter 190.

The base substrate 100 has a plate shape and may be made of a transparent material, for example, glass, quartz, synthetic resin, or the like. The gate wiring 110 is formed in the first direction on the base substrate 100, and the gate insulating layer 120 is formed on the base substrate 100 to cover the gate wiring 110. In this case, the gate insulating layer 120 may be formed of an inorganic material, for example, silicon oxide (SiOx) or silicon nitride (SiNx).

The data line 130 is formed on the gate insulating layer 120 in a second direction crossing the first direction. At this time, the second direction is preferably a direction orthogonal to the first direction.

The thin film transistor TFT includes a gate electrode G, an active pattern A, an ohmic contact pattern O, a source electrode S, and a drain electrode D. The gate electrode G is branched from the gate wiring 110, and the active pattern A is formed on the gate insulating layer 120 to overlap the gate electrode G. The source electrode D is branched from the data line 130 to overlap the active pattern A, and the drain electrode D is spaced apart from the source electrode D. Overlapping with the gate insulating layer 120. The ohmic contact pattern O is formed between the source electrode S and the active pattern A, and between the drain electrode D and the active pattern A, respectively, and has a contact resistance between the electrode and the pattern. Decreases.

Meanwhile, the gate wiring 110 and the gate electrode G are gate metal patterns formed by patterning a gate metal layer deposited on the base substrate 100, and the data wiring 130, the source electrode S, and The drain electrodes D are data metal patterns formed by patterning the data metal layer. The gate metal patterns, the gate insulating layer 120, the active pattern A, the ohmic contact pattern O, and the data metal patterns may be formed in this order.

The PIN diode DI is formed on the gate insulating layer 120 to be electrically connected to the thin film transistor TFT. In this case, the PIN diode DI includes a lower electrode part LP, a light conversion semiconductor part 140, and an upper electrode part HP.

The lower electrode part LP is formed on the gate insulating layer 120 to cover the drain electrode D, and thus is in direct contact with the drain electrode D to be electrically connected thereto. That is, after the data metal patterns are formed, a lower electrode layer is formed to cover the data metal patterns, and then the lower electrode layer LP is formed by patterning the lower electrode layer. As a result, the lower electrode part LP may be formed on the drain electrode D to completely or at least partially cover the drain electrode D.

The lower electrode part LP may be formed of a conductive material having a lower resistance than the drain electrode D, that is, the data metal patterns. In addition, the lower electrode part LP may be formed of a material substantially similar to the thermal expansion coefficient of the adjacent gate insulating layer 120 or the photoconversion semiconductor part 140, thereby lowering the thermal expansion stress. For example, the lower electrode part LP may be made of indium tin oxide (ITO), which is a transparent conductive material.

The photoconversion semiconductor unit 140 is formed on the lower electrode part LP to convert light applied from the outside into electricity. The photoconversion semiconductor unit 140 includes an N-type semiconductor layer 142 formed on the lower electrode part LP, an intrinsic semiconductor layer 144 formed on the N-type semiconductor layer 142, and the intrinsic semiconductor layer. P-type semiconductor layer 146 formed on 144.

The upper electrode portion HP is formed on the photoconversion semiconductor portion 140. The upper electrode part HP may be made of a transparent conductive material, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or the like, to transmit light applied from the outside.

The diode protection layer 150 is formed on the gate insulating layer 120 to cover the data line 130, the thin film transistor TFT, and the PIN diode DI. In this case, a bias contact hole 152 exposing a portion of the upper portion of the PIN diode DI, that is, a portion of the upper electrode portion HP, is formed in the diode protection layer 150.

In the present exemplary embodiment, the diode protection film 150 may be formed of an organic insulating film that can flatten the top surface, but preferably, an inorganic insulating film made of silicon oxide (SiOx) or silicon nitride (SiNx).

The bias wire 160 is formed on the diode protection layer 150 to be in electrical contact with the upper electrode portion HP through the bias contact hole 152. The bias wire 160 may receive a reverse bias and a forward bias from an external bias driver (not shown).

The bias wire 160 is formed on the diode protection film 150 to be substantially parallel to the data wire 130. In this case, the bias line 160 may be formed to be adjacent to or overlap with the data line 130 to minimize a region overlapping with the PIN diode DI to increase a fill factor.

Meanwhile, the bias wire 160 may include a double layer structure, for example, a transparent wire part 162 and a metal wire part 164. The transparent wiring part 162 is formed on the diode protection layer 150 to be in electrical contact with the upper electrode part HP through the bias contact hole 152. In this case, the transparent wiring part 162 is made of substantially the same material as the upper electrode part HP, that is, a transparent conductive material. The metal wire part 164 is formed on the transparent wire part 162 and is electrically connected to the bias driver. In the present exemplary embodiment, the transparent wiring portion 162 may be formed to have a larger area than the metal wiring portion 164, and may be omitted in some cases.

The light blocking unit 170 is formed on the thin film transistor TFT to cover the thin film transistor TFT. Therefore, the light blocking unit 170 may block the light applied from the outside into the thin film transistor TFT. In the present exemplary embodiment, the light blocking unit 170 covers the thin film transistor TFT within a range not overlapping with the PIN diode DI in order not to block light applied to the PIN diode DI. It is preferable. That is, the light blocking unit 170 may be formed at a position capable of covering the source electrode S and a part of the active pattern A. FIG.

The light blocking unit 170 is simultaneously formed when the bias wire 160 is formed, and is formed on the diode protection layer 150. That is, the light blocking unit 170 may be formed together with the bias wiring 160 through a process of forming the bias wiring 160. Therefore, the light blocking unit 170 may also be formed in a double layer structure similarly to the bias wiring 160. However, the light blocking unit 170 may be formed in a single layer structure in which the lower layer corresponding to the transparent wiring unit 162 is removed, unlike FIGS. 1 and 2. On the other hand, the light blocking unit 170 is preferably formed to be connected to the bias wire 160 to be integrated. However, the light blocking unit 170 may be formed to be spaced apart from the bias wiring 160.

The outer passivation layer 180 is formed on the diode passivation layer 150 to cover the bias line 160 and the light blocking unit 170. The outer passivation layer 180 may be formed of an inorganic insulating layer, but may also be an organic insulating layer capable of planarizing an upper surface thereof. The light blocking unit 170 may be formed on the diode protection layer 150 as shown in FIG. 2, but may be formed to cover a portion of the thin film transistor TFT on the outer protection layer 180. have.

The optical wavelength converter 190 may be disposed on the outer passivation layer 180 and may convert an X-ray applied from the outside into a wavelength absorbed by the PIN diode DI. That is, the optical wave converter 190 may be a scintillator capable of converting the X-rays into visible light, for example, green light.

In the present embodiment, the light wavelength converter 190 may be attached in the form of a film on the outer passivation layer 180. When the optical wavelength converter 190 has a film shape, an adhesive layer for attaching the optical wavelength converter 190 to the outer protective film 180 between the optical wavelength converter 190 and the outer passivation layer 180 ( Not shown) may be formed.

Alternatively, the light wavelength converter 190 may be formed by depositing a chemical vapor deposition method on the surface of the outer passivation layer 180. That is, the light wavelength converter 190 may be formed by growing a crystal from the surface of the outer passivation layer 180. In this case, the outer passivation layer 180 is preferably an inorganic insulating layer including silicon oxide (SiOx), etc., and the surface roughness of the outer passivation layer 180 is increased to induce crystal growth or a plurality of irregularities. Patterns (not shown) may be formed, or a crystal seed layer (not shown) in which a plurality of crystal seeds are dispersed may be formed.

In the present exemplary embodiment, the optical wavelength converter 180 may be disposed on the diode protection layer 150 by omitting the outer passivation layer 180 or may be formed by growing a crystal from the surface of the diode protection layer 150. Can be.

<Example 2>

3 is a cross-sectional view illustrating a part of an X-ray detector according to a second exemplary embodiment of the present invention.

The X-ray detector according to the present embodiment is substantially the same as the X-ray detector of the first embodiment described with reference to FIGS. 1 and 2, except that the X-ray detector further includes a passivation film 200. Detailed description of the components will be omitted, and the same components as the first embodiment will be given the same reference numerals.

Referring to FIG. 3, the X-ray detector according to the present exemplary embodiment further includes a passivation film 200 formed between the lower electrode part LP and the thin film transistor TFT.

The passivation layer 200 is formed before the lower electrode portion LP is formed to cover the data metal patterns including the data line 130, the source electrode S, and the drain electrode D. ) Is formed on. In this case, a drain contact hole 210 may be formed in the passivation layer 200 to expose a portion of the drain electrode D.

The lower electrode part LP is formed on the passivation film 200 and electrically connected to the drain electrode D through the drain contact hole 210. In the present exemplary embodiment, the lower electrode part LP may be formed on the passivation layer 200 to cover the drain electrode D completely or partially.

On the other hand, the passivation film 200 is preferably made of an inorganic insulating film, as shown in Figure 3, but may be formed of an organic insulating film that is relatively thick to planarize the upper surface. As described above, when the passivation layer 200 is formed relatively thick, an interval between the PIN diode DI and the thin film transistor TFT is increased, so that the PIN diode DI is formed on the thin film transistor TFT. It can suppress to some extent an adverse effect.

As described above, according to the exemplary embodiments, as the lower electrode part having a lower resistance than the drain electrode of the thin film transistor and made of a transparent conductive material is formed on the drain electrode to cover the drain electrode, a PIN diode is formed. It can even be formed in the region. That is, the area of the PIN diode is increased compared to the prior art, thereby increasing the area where X-rays can be applied.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

1 is a plan view illustrating a part of an X-ray detector according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II ′ of FIG. 1.

3 is a cross-sectional view illustrating a part of an X-ray detector according to a second exemplary embodiment of the present invention.

<Short Description of Main Drawing Numbers>

100: base substrate 110: gate wiring

120: gate insulating film 130: data wiring

TFT: Thin Film Transistor DI: PIN Diode

140: light conversion semiconductor portion 150: diode protective film

152: bias contact hole 160: bias wiring

162: transparent wiring portion 164: metal wiring portion

170: light shield 180: outer protective film

190: wavelength conversion unit 200: passivation film

Claims (17)

Gate and data lines formed to cross each other on the substrate; A thin film transistor formed on the substrate and electrically connected to the gate and data lines, respectively; A lower electrode portion formed on the drain electrode so as to cover the drain electrode of the thin film transistor and electrically connected to the drain electrode, a photoconversion semiconductor portion disposed on the lower electrode portion, and the photoconversion semiconductor portion PIN diode including an upper electrode portion made of a transparent conductive material; A diode protection layer formed to cover the PIN diode and having a bias contact hole exposing a portion of an upper portion of the PIN diode; A bias wiring formed on the diode protection layer and electrically contacting an upper portion of the PIN diode through the bias contact hole; And an optical wavelength converter disposed on the diode protection layer and converting an X-ray applied from the outside into a wavelength absorbed by the PIN diode. The bias wiring may include a transparent wiring portion formed on the diode protection layer and electrically contacting an upper portion of the PIN diode through the bias contact hole and made of a transparent conductive material, and a metal wiring portion formed on the transparent wiring portion. X-ray detector characterized by. The method of claim 1, wherein the lower electrode portion An X-ray detector formed on the substrate to cover the drain electrode and electrically connected to the drain electrode. The passivation film of claim 1, further comprising a passivation layer under the lower electrode part to cover and protect the thin film transistor and to expose a portion of the drain electrode. And the lower electrode portion is formed on the passivation layer to cover the drain electrode and is electrically connected to the drain electrode through the drain contact hole. The method of claim 1, wherein the lower electrode portion X-ray detector, characterized in that made of a conductive material having a lower resistance than the drain electrode. The method of claim 4, wherein the lower electrode portion X-ray detector, characterized in that the transparent conductive material made of indium tin oxide (ITO). The X-ray detector of claim 1, wherein an outer passivation layer formed on the diode passivation layer is further formed under the optical wavelength conversion unit to cover the bias wiring. The X-ray detector of claim 6, wherein the light wavelength converter is attached to the outer passivation layer in a film form. The X-ray detector of claim 6, wherein the light wavelength converter is formed by depositing on the outer passivation layer. delete The X-ray detector of claim 1, further comprising a light blocking unit formed on the thin film transistor to cover the thin film transistor. The method of claim 10, wherein the light blocking unit And a portion of the thin film transistor so as not to overlap the PIN diode. Forming a thin film transistor on the substrate, the gate and data lines crossing each other and electrically connected to the gate and data lines, respectively; A lower electrode portion disposed on the drain electrode and electrically connected to the drain electrode to cover the drain electrode of the thin film transistor, an optical conversion semiconductor portion disposed on the lower electrode portion, and an optical conversion semiconductor portion; Forming a PIN diode comprising an upper electrode portion formed of a transparent conductive material; Forming a diode protection layer covering the PIN diode and having a bias contact hole exposing a portion of an upper portion of the PIN diode; Forming a bias line on the diode protection layer in electrical contact with an upper portion of the PIN diode through the bias contact hole; And Disposing an X-ray applied from the outside on the diode passivation layer to convert an optical wavelength conversion unit into a wavelength absorbed by the PIN diode; The bias wiring may include a transparent wiring portion formed on the diode protection layer and electrically contacting an upper portion of the PIN diode through the bias contact hole and made of a transparent conductive material, and a metal wiring portion formed on the transparent wiring portion. Method of manufacturing an x-ray detector, characterized in that. 13. The method of claim 12, wherein forming the PIN diode is And covering the drain electrode to form a lower electrode part in direct electrical contact with the drain electrode. 13. The method of claim 12, further comprising forming a passivation film having a drain contact hole covering and protecting the thin film transistor and exposing a portion of the drain electrode before forming the PIN diode. Method of manufacturing the X-ray detector. 15. The method of claim 14, wherein forming the PIN diode And forming the lower electrode portion on the passivation layer covering the drain electrode and electrically connected to the drain electrode through the drain contact hole. The method of claim 12, wherein the lower electrode portion Method of manufacturing an X-ray detector, characterized in that made of indium tin oxide (ITO), a transparent conductive material. Gate and data lines formed to cross each other on the substrate; A thin film transistor formed on the substrate and electrically connected to the gate and data lines, respectively; A lower electrode portion formed on the drain electrode so as to cover the drain electrode of the thin film transistor and electrically connected to the drain electrode, a photoconversion semiconductor portion disposed on the lower electrode portion, and the photoconversion semiconductor portion PIN diode including an upper electrode portion made of a transparent conductive material; A diode protection layer formed to cover the PIN diode and having a bias contact hole exposing a portion of an upper portion of the PIN diode; A bias wiring formed on the diode protection layer and electrically contacting an upper portion of the PIN diode through the bias contact hole; And an optical wavelength converter disposed on the diode protection layer and converting an X-ray applied from the outside into a wavelength absorbed by the PIN diode. The thin film transistor may include: a gate electrode formed on the substrate and electrically connected to the gate wiring; a gate insulating film formed on the substrate to cover the gate electrode; an active pattern formed on the gate insulating film to overlap the gate electrode; A source electrode electrically connected to a data line and at least partially formed on the active pattern, and at least a portion of the drain electrode spaced apart from the source electrode; The photo-conversion semiconductor unit includes an N-type semiconductor layer formed on the lower electrode part, an intrinsic semiconductor layer formed on the N-type semiconductor layer, and an P-type semiconductor layer formed on the intrinsic semiconductor layer. .

Images