KR102543082B1 - Digital x-ray detector substrate with backside scintillator, digital x-ray detector and method of fabricating thereof - Google Patents

Abstract

The present invention relates to a substrate for a digital X-ray detector to which a backside scintillator is applied, a digital X-ray detector, and a method for manufacturing the same. and a base substrate including a surface and a second surface on which the light conversion unit is disposed as a rear surface of the first surface.

Description

Substrate for digital X-ray detector applied with backside scintillator, digital X-ray detector and manufacturing method thereof

The present invention relates to a substrate for a digital X-ray detector to which a backside scintillator is applied, a digital X-ray detector, and a method for manufacturing the same.

A diagnostic X-ray examination method, which is currently widely used for medical purposes, is taken using an X-ray detection film, and a predetermined film printing time must be passed in order to know the result. However, in recent years, thanks to the development of semiconductor technology, a digital X-ray detector using a thin film transistor has been researched/developed. The X-ray detector has the advantage of using a thin film transistor as a switching element and diagnosing a result in real time immediately after taking an X-ray.

In general, an X-ray detector is composed of amorphous Se (Selenium) stacked on the upper layer of a thin film transistor array substrate and a transparent electrode formed on the amorphous Se. When X-rays are converted into visible light by a scintillator, the visible light is converted into an electrical signal by a pin diode and an indirect method undergoes a series of signal processing. type DXD).

Meanwhile, to provide a thin film transistor array substrate to detect X-rays, a process of forming thin film transistors on the substrate is required, and it is also necessary to prevent each thin film transistor from being exposed to X-rays. In particular, in the process of forming a pin diode required for an X-ray detector, and in a manufacturing process, a thin film transistor in the detector is required to be less affected by X-rays.

In constituting a digital X-ray detector, the present invention proposes a detector in which a photoconversion unit and a transistor are disposed on both sides of a base substrate and a method for manufacturing the same.

The present invention proposes a detector that reduces the thickness of an X-ray detector and protects a TFT element from X-rays by arranging a diode and a TFT on the same layer on the same plane, and a method for manufacturing the same.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned above can be understood by the following description and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations indicated in the claims.

A substrate for a digital X-ray detector according to an embodiment of the present invention includes a base substrate including a first surface divided into a plurality of photo-sensing pixel areas and a second surface on which a light conversion unit is disposed on a rear surface of the first surface.

A substrate for a digital X-ray detector according to another embodiment of the present invention includes a light blocking layer and a bias electrode disposed in a pixel area on a first surface of a base substrate, a buffer layer disposed on the light blocking layer and the bias electrode, and a plurality of pixel areas of the buffer layer. A plurality of transistors respectively disposed in the transistor region, a plurality of photo-sensing units each disposed in the diode region of the plurality of pixel regions of the buffer layer and including a first electrode part, a PIN layer, and a second electrode part, a transistor in the pixel region, A first source-drain electrode connecting the light sensing unit and a second source-drain electrode connecting the pixel electrode and the transistor of the pixel area are included.

The second electrode portion of the photo-sensing unit of the substrate for a digital X-ray detector according to another embodiment of the present invention includes the same material as the gate electrode of the transistor.

A digital x-ray detector according to another embodiment of the present invention is divided into a plurality of light-sensing pixel areas and includes a base including a first surface on which a plurality of transistors and a plurality of light-sensing units are disposed and a second surface that is a rear surface of the first surface. It includes a substrate, a light conversion unit disposed on the second surface, and a control circuit unit for controlling the transistor and light sensing unit on the first surface.

A method of manufacturing a digital x-ray detector according to another embodiment of the present invention provides pixels on a first surface of a base substrate including a first surface divided into a plurality of photo-sensing pixel areas and a second surface that is a rear surface of the first surface. Disposing a light blocking layer and a bias electrode corresponding to the region, disposing a photo-sensing unit on a first surface, disposing a transistor element on the first surface, and disposing a light conversion unit on a second surface. .

When the present invention is applied, the thickness of the X-ray detector can be reduced by arranging the diode and the TFT on the same layer on the same plane in constructing the digital X-ray detector.

When the present invention is applied, since the same mask can be used in the process of arranging TFTs and diodes in manufacturing a digital X-ray detector, process efficiency can be increased.

When the present invention is applied, since the thin film transistor element is disposed after the photodiode is disposed in manufacturing the digital x-ray detector, stability of the element can be realized.

The effects of the present invention are not limited to the above-mentioned effects, and those skilled in the art can easily derive various effects of the present invention from the configuration of the present invention.

1 is a diagram showing a substrate area of a DXD (Digital X-ray Detector), which is an embodiment of the present invention.
2 is a diagram illustrating a configuration of an X-ray detector in which a light conversion unit is disposed on a substrate on which transistors are disposed according to an exemplary embodiment.
3 is a diagram showing the configuration of an X-ray detector according to an embodiment of the present invention.
4 is a diagram showing a pixel structure according to an exemplary embodiment of the present invention.
5 is a view showing a process of manufacturing a light blocking layer, a bias line, and a pin diode.
6 is a diagram showing a process of arranging a transistor device according to an embodiment of the present invention.
7 is a view showing a process of disposing an interlayer insulating layer according to an embodiment of the present invention.
8 and 9 are diagrams illustrating a process of arranging a pixel electrode according to an embodiment of the present invention.
10 is a diagram showing a process process according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification. In addition, some embodiments of the present invention are described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

Hereinafter, the provision or arrangement of an arbitrary element on the "upper (or lower)" or "upper (or lower)" of the base material means that the arbitrary element is provided or disposed in contact with the upper (or lower) surface of the base material. It is not meant to mean, but is not limited to, not including other components between the substrate and any components provided or disposed on (or under) the substrate. In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to that other element, but intervenes between each element. It will be understood that may be "interposed", or each component may be "connected", "coupled" or "connected" through other components.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

1 is a diagram showing a substrate area of a DXD (Digital X-ray Detector), which is an embodiment of the present invention.

A digital X-ray detector 1 according to an embodiment of the present invention includes a pixel unit P, a bias driver 10, a gate driver 20, and a readout integrated circuit 30. The X-ray detector 1 includes a base substrate (303 in FIG. 4) on which a plurality of transistors (thin film transistors) and a light sensing unit are disposed, and a light conversion unit such as a scintillator is disposed on the other surface of the base substrate. This will be described later.

The pixel unit P senses the X-rays emitted from the X-ray generator, photoelectrically converts the detected signals, and outputs them as electrical detection signals. The pixel unit P includes a plurality of photo-sensing pixels arranged in a matrix form near a point where a plurality of gate lines GL and a plurality of data lines DL intersect. The plurality of gate lines GL and the plurality of data lines DL may be disposed substantially orthogonal to each other. Although FIG. 1 shows 16 light-sensing pixels P arranged in 4 rows and 4 columns as an example, the present invention is not limited thereto, and the number of light-sensing pixels P may be variously selected.

Each of the photo-sensing pixels P detects X-rays and responds to a photo-detector (PD, Photo Diode) that outputs a detection signal, for example, a photo-detection voltage, and an electrical signal output from the photo-detector (PD) to a gate pulse. A transistor (Tr, Transistor) is provided as a switching element that transmits the

The light detector PD according to the present invention detects the X-ray emitted from the X-ray generator and outputs the detected signal as the detection signal. The photodetector PD is a device that converts incident light into an electrical signal by a photoelectric effect, and may be, for example, a PIN diode.

The transistor Tr is a switching element that transmits a detection signal output from the photodetector PD. A gate electrode of the transistor is electrically connected to the gate line GL, and a source electrode of the transistor is electrically connected to the readout integrated circuit through the data line DL.

The bias driver 10 applies a driving voltage to a plurality of bias lines BL. The bias driver may selectively apply reverse bias or forward bias to the light sensing unit.

The gate driver 20 sequentially applies gate pulses having a gate-on voltage level to the plurality of gate lines GL. Transistors of the photo-sensing pixels P are turned on in response to the gate pulse. When the transistor is turned on, the detection signal output from the photodetector PD is input to the readout integrated circuit 30 through the transistor and the data line DL.

The gate driver 20 may be formed in the form of an IC and mounted on one side of the pixel unit P or formed on the same substrate as the pixel unit P through a thin film process.

The readout integrated circuit 30 reads out a detection signal output from a turned-on transistor in response to a gate pulse. The readout integrated circuit 30 reads out the detection signal output from the light-sensing pixel P in an offset readout section for reading out an offset image and an X-ray readout section for reading out the detection signal after X-ray exposure.

The readout integrated circuit 30 reads the detection signal and transmits it to a predetermined signal processing device, digitizes the detection signal in the signal processing device, and displays the detection signal as an image. The readout integrated circuit 30 may include a signal detector 31 and a multiplexer 32 . In this case, the signal detector 31 includes a plurality of amplification units corresponding to the plurality of data lines DL on a one-to-one basis, and each amplification unit includes an amplifier OP, a capacitor CP, and a reset device SW.

In the configuration of FIG. 1 , the bias driver 10 , the gate driver 20 , and the readout integrated circuit 30 are collectively referred to as a control circuit unit. The transistor and the light sensing unit are controlled by the control of the control circuit unit, and a signal sensed by the light sensing unit may be detected.

Meanwhile, a scintillator is coupled to the substrate configured as shown in FIG. 1 . The scintillator may be configured in the form of a film. X-rays are converted into visible light by the scintillator and incident or absorbed by a photodetector, which is a photodiode. A component including the scintillator is referred to as the light conversion unit 150 .

2 is a diagram illustrating a configuration of an X-ray detector in which a light conversion unit is disposed on a substrate on which transistors are disposed according to an exemplary embodiment.

Looking at the configuration of the X-ray detector 200, the light conversion unit 150 is disposed on the substrate 100. As a configuration of the light conversion unit 150, a pacification layer 154 disposed on the substrate and a scintillator 153 disposed on the pacification layer may be deposited or grown on the pacification layer 154 and disposed thereon. there is. In addition, protective layers 152 and 151 for shielding the scintillator 153 from external air or the like are disposed. In one embodiment, 152 may include an adhesive layer such as Parylene, and 151 may use a PET film. Although the light conversion unit 150 is illustrated, the present invention is not limited thereto.

The substrate 100 may also be divided into two layers. It can be divided into a layer 102 on which a transistor is disposed and a layer 101 on which a light sensing unit (PD) such as a pin diode is disposed. In the configuration of FIG. 2 , the transistor may be composed of an oxide TFT. 2 shows a structure in which a light conversion unit 150 including a scintillator is located on top of the TFT layer 102 and the diode layer 101, and in this case, X-rays are irradiated from the top. However, in the structure shown in FIG. 2 , the transistor elements constituting the TFT layer 102 may be affected by the X-ray passing through the scintillator 153 . This may increase damage to the device.

Accordingly, the present specification examines a structure in which TFT elements are shielded from light. To this end, the light conversion unit 150 of FIG. 2 has a configuration disposed opposite to the diode layer 102 on which the pin diode is disposed based on the TFT layer 102.

3 is a diagram showing the configuration of an X-ray detector according to an embodiment of the present invention. 3 is a substrate 300 for a digital X-ray detector, a base substrate 303, a first surface of the base substrate 303 is composed of a layer 310 disposed with a diode and a TFT, and a second surface is a light conversion unit ( 350) is arranged.

It is composed of a layer 310 arranged with diodes and TFTs and a base substrate 303 made of glass as an example. On glass 303, diodes and TFTs are disposed. Meanwhile, the light conversion unit 350 is disposed under the glass 303, and unlike FIG. 2, the planarization film 154 is removed. Since the light conversion unit 350 is directly disposed on the glass 303 that is the base substrate, a separate planarization layer does not need to be disposed. In the embodiment of FIG. 3 , since the scintillator is deposited and grown on the base substrate 303 as it is, X-rays that pass through the base substrate 303 instead of passing through an intermediate planarization film do not damage elements in the transistor area. Since the base substrate 303 has a higher X-ray shielding rate than the planarization film 154, it can protect the elements.

Therefore, the configuration of the substrate 300 for an X-ray detector according to an embodiment of the present invention is composed of a light conversion unit 350 and a base substrate 303, and a TFT and a diode are formed on the first surface of the base substrate 303. can be placed. The base substrate 303 is made of glass as an example, but the present invention is not limited thereto. The light conversion unit 350 is disposed on the second surface of the base substrate 303 . X-rays are incident from a downward direction. Meanwhile, the TFT of FIG. 3 may include a separate light blocking layer to protect the element from X-rays. When FIGS. 1 and 3 are applied, a TFT/diode and a light conversion unit (including a scintillator) are disposed on both sides of the base substrate 303, respectively. This can reduce the thickness of the X-ray detector by arranging the diode and the TFT on the same layer on the same plane. In addition, since the same mask can be used in the process of arranging TFTs and diodes, process efficiency can be increased. Let's take a closer look.

4 is a diagram showing a pixel structure according to an exemplary embodiment of the present invention. The base substrate 303 of the X-ray detector is divided into a first surface and a second surface. The first surface is divided into a plurality of photo-sensing pixel areas. On the second surface, the light conversion unit 350 is disposed.

As shown in FIG. 4 , the pixel area PXL for light sensing may be divided into a transistor area TR and a diode area PD.

A light blocking layer 311a and a bias electrode 311b are disposed in the pixel region of the first surface of the base substrate 303, and they may be disposed using one material. The light blocking layer 311a is disposed in the transistor region. The bias electrode 311b is disposed in the diode region.

The light blocking layer 311a is to protect transistor elements from X-rays incident from a lower direction. Process efficiency can be increased by arranging the light blocking layer 311a and the bias electrode 311b using one mask.

A buffer layer 312 is disposed on the first surface of the base substrate 303 . As a result, the buffer layer 312 is also disposed on the light blocking layer 311a and the bias electrode 311b. However, a contact hole is disposed using one mask so that the bias electrode 311b is electrically connected to the photo-sensing unit.

On the buffer layer 312 , transistors are disposed in the transistor region TR of each pixel region PXL. One or more transistors may be disposed in the transistor region TR according to a driving method, and a plurality of transistors may be disposed corresponding to the number of pixel regions on the entire base substrate 303 .

In addition, on the buffer layer 312 , light sensing units 315 , 317a , 317b , 317c , and 325b are respectively disposed in the diode region PD of each pixel region PXL. Depending on the driving method, one or more photo-sensing units may be disposed in the diode region PD, and a plurality of photo-sensing units may be disposed on the entire base substrate 303 corresponding to the number of pixel regions.

Also, the transistor and the light sensing unit in one pixel area are electrically connected by the first source-drain electrode 331b. The transistor in the pixel area and the pixel electrode 341 are electrically connected by the second source-drain electrode 331a.

In the configuration shown in FIG. 4, a TFT transistor and a diode are disposed on the upper portion of a base substrate 303 of which a glass substrate is used as an embodiment, and a photo-conversion unit 350 including a scintillator is disposed on the lower portion. By pre-depositing the photo-sensing unit including 317a, 317b, and 317c, damage to elements in the transistor region TR that may occur during PIN deposition may be prevented. In particular, in the case of an oxide device, since a PIN is pre-deposited and then an active layer is disposed, the effect of protecting the device is great.

In addition, since a process of simultaneously depositing the same material among elements constituting the light sensing unit and elements constituting the transistor is applied, the number of masks can be reduced and process efficiency can be increased. For example, in FIG. 4 , the light blocking layer 311a and the bias electrode 311b can be disposed at the same time, and the gate electrode 325a and the second electrode unit 325b of the light sensing unit can be disposed at the same time. It has the effect of increasing the efficiency and reducing the mask.

In addition, in the configuration shown in FIG. 4, X-rays are irradiated from the bottom, and X-rays transmitted through the light conversion unit 350 such as a scintillator pass through the base substrate 303 to double shield the X-rays, thereby preventing damage to the oxide element. can be reduced

Hereinafter, a process of manufacturing an X-ray detector according to an embodiment of the present invention will be described. It will be examined in detail in FIGS. 5 to 9 .

5 is a view showing a process of manufacturing a light blocking layer, a bias line, and a pin diode. In S501, the light blocking layer 311a and the bias line 311b are simultaneously disposed on the base substrate 303. And, after coating the buffer layer 312 on the entire surface as in S502, a contact hole 312h through which the bias line 311b can contact the pin diode is formed. After that, arrange the pin diode as in S503. In one embodiment, the first electrode part 315 of the pin diode is made of a transparent conductive material.

The first electrode part 315 electrically contacts the bias line 311b through the contact hole 312h formed in S502. 317a, 317b, and 317c may be configured as the PIN layer 317 constituting the pin diode. In an embodiment, a positive (P) semiconductor layer 317a, an intrinsic (I) semiconductor layer 317b, and a negative (N) semiconductor layer 317c may be formed. According to another embodiment of the present invention, a positive (P) semiconductor layer 317c, an intrinsic (I) semiconductor layer 317b, and a negative (N) semiconductor layer 317a may be formed.

That is, in an embodiment of disposing the photo-sensing unit, the first electrode unit 315 electrically contacting the bias electrode 311b is disposed in the first contact hole 312h of the diode region. And deploy the PIN layer.

In the PIN layer, a P (Positive) semiconductor layer 317a is disposed on the first electrode portion 315, and an I (Intrinsic) type semiconductor layer 317b is disposed on the P (Positive) semiconductor layer 317a. This is a structure in which an N (Negative) semiconductor layer 317c is disposed on an I (Intrinsic) type semiconductor layer 317b. This can be sequentially increased, and as shown in S503, since the structure is deposited before the transistor element is disposed, damage to the transistor element composed of the oxide element can be reduced.

As an example of forming the PIN layer 317, it is laminated through a plasma enhanced chemical vapor deposition (PECVD) process and then formed through a dry etching process. In step S503, since no transistor is formed yet, damage to the oxide semiconductor device can be minimized.

In FIG. 5 , the first electrode part 315 is disposed on the buffer layer 312 and is electrically connected to the bias electrode 311b through a contact hole 312h formed in the buffer layer 312 . It is a structure in which the first electrode part 315 is disposed on the bias electrode 311b, and since the first electrode part 315 and the PIN layer 317 are formed in a state in which no element is formed in the transistor region, it can be applied to the element. damage can be minimized. In addition, since transistors are later disposed in the transistor region, the stacked height can be reduced.

6 is a diagram showing a process of arranging a transistor device according to an embodiment of the present invention.

An active layer 320 is disposed on the light blocking layer 311a (S511). A gate insulator 321 is disposed thereon, and a gate electrode 325a and a second electrode portion 325b of the pin diode are formed using a conductive material. As shown in S512, since the gate electrode 325a of the transistor and the second electrode portion 325b of the pin diode are simultaneously disposed using one material, the number of masks can be reduced and process efficiency can be increased. In particular, since the height of the entire structure is reduced in a structure in which transistors and diodes are disposed on one layer, thinning is possible.

Then, a portion of the active layer 320 is doped using the gate electrode 325a. Conductive regions 320a and 320c and non-conductive regions 320b are formed by doping (S512).

Here, since the active layer is deposited as shown in FIG. 6 after disposing the pin diode as shown in FIG. 5, there is an effect of preventing deterioration of device characteristics of the oxide semiconductor. In the process of depositing the fin diode, it is possible to prevent the influence of hydrogen on IGZO by the process of FIGS. 5 and 6 .

7 is a view showing a process of disposing an interlayer insulating layer according to an embodiment of the present invention. In one embodiment, the interlayer dielectric may be an oxide ILD. Holes 329h1, 329h2, 329h3, and 329h4 for disposing the interlayer insulating layer 329 and electrically connecting the transistor to other components are formed (S521). Among them, 329h3 provides a function of connecting with other electrical elements to prevent floating of the light blocking layer 311a.

Next, source-drain electrodes 331a and 331b are formed to cover the holes 329h1, 329h2, 329h3, and 329h4. These connect the conductive regions 320a and 320c, the light blocking layer 311a, and the second electrode portion 325b of the pin diode (S522).

Looking at the result calculated in step S522, the transistor includes an active layer having conductive regions 320a and 320c and a semiconductor region 320b on the buffer layer 312, a gate insulating film 321 disposed on the active layer, and a gate A gate electrode 325a disposed on the insulating layer 321 is included. Also, the first source-drain electrode 331b electrically connects the conductive first region 320c of the active layer and the second electrode portion 325b.

Since the transistor and the diode are disposed on the same layer, they can be connected using the first source-drain electrode 331b, which can be connected by arranging a plurality of contact holes in the interlayer insulating film 329. In addition, since the contact holes are formed using one mask as suggested in S521, process efficiency can be increased.

In addition, since the light blocking layer 311a and the first source-drain electrode 331b can be connected in the same process, floating of the light blocking layer 311a can be prevented. In particular, the light blocking layer 311a is simultaneously disposed with the bias electrode 311b, and the contact hole 329h3 exposing the light blocking layer 311a is formed simultaneously with the contact holes exposing the other electrodes as in step S521. Therefore, when the embodiments of the present invention are applied, since an additional process or mask is not required in disposing the light blocking layer 311a, process efficiency is increased and mask reduction effect is obtained.

8 and 9 are diagrams illustrating a process of arranging a pixel electrode according to an embodiment of the present invention.

In FIG. 8 , a passivation layer (PAS) 335 is disposed on the substrate of S522 of FIG. 7 . At this time, a hole 335h exposing the source-drain electrode 331a is formed. As shown in FIG. 9 , a pixel electrode (PXL) 341 contacting the source-drain electrode 331a is disposed using the hole 335h.

After manufacturing the substrate in the process of FIGS. 5 to 9 , the light conversion unit 350 is deposited on the lower surface of the glass 303 . Deposition of the light conversion unit 350 may grow the scintillator 353 and dispose the parellin 352 and the protective layer 351 thereon.

Looking at an example in which a mask is used in the processes of FIGS. 5 to 9, a first mask is used in the process of S501 (forming a light blocking layer and a bias) of FIG. 5, and a second mask is used in S502 (forming a buffer hole 312h). , A third mask is used in S503 (pin diode formation).

In addition, the fourth mask is used in the process of forming the active layer (S511) of FIG. 6, and the fifth mask is used to form the gate electrode 325a and the second electrode portion 325b of the pin diode in S512.

Next, as in S521 of FIG. 7, the sixth mask is used to form the holes 329h1, 329h2, 329h3, and 329h4 after disposing the interlayer insulating layer 329, and the source-drain electrodes 331a and 331b as in S522. ), a seventh mask is used to form.

Next, as shown in FIG. 8 , the eighth mask is used to form the hole 335h on the protective layer 335 , and the ninth mask is used to form the pixel electrode 341 as shown in FIG. 9 . As a result, a substrate can be manufactured using a total of nine masks.

In the case of the X-ray detector manufactured by the processes of FIG. 4 and FIGS. 5 to 9, which are manufacturing methods thereof, X-rays transmitted through the scintillator 353 are prevented from entering the transistor element by the light blocking layer 311a. As a result, it is possible to prevent damage to the transistor elements due to X-rays, thereby increasing the stability of the elements.

In the configuration shown in FIG. 9 , the scintillator 353 is directly disposed on the second surface of the base substrate 303 as shown in FIGS. 3 and 4 . By disposing and growing the scintillator crystal on the second surface, a separate material is not disposed between the second surface and the scintillator 353, and light efficiency can be increased.

Conventionally, after disposing a transistor and a light sensing unit, a planarization film is disposed thereon, and a scintillator is grown thereon. However, when the embodiment of the present invention is applied, since the scintillator is deposited and grown on the base substrate 303 as it is, optical loss occurring in the intermediate planarization film can be reduced.

10 is a diagram showing a process process according to an embodiment of the present invention.

A light blocking layer 311a and a bias electrode corresponding to the pixel areas are formed on the first surface of the base substrate 303 including a first surface divided into a plurality of photo-sensing pixel areas and a second surface that is a rear surface of the first surface. (311b) is arranged (S900). Refer to S501 of FIG. 5 above. Then, a buffer layer 312a including a first contact hole 312h exposing a part of the bias electrode 311b is disposed on the first surface (S910). Refer to S502 of FIG. 5 above.

In the next process, the light sensing unit is disposed on the buffer layer 312 in the diode area of the pixel area. In more detail, refer to S503 of FIG. 5 as a process (S920) of disposing the first electrode part 315 of the PIN diode and the PIN layers 317a, 317b, and 317c.

In the next process, transistors are disposed on the buffer layer 312 in the transistor region of the pixel region. In more detail, the active layer 320 and the gate insulating layer 321 are disposed (S930), and the gate electrode 325a and the second electrode portion 325b of the PIN diode are disposed of the same material (S940). Refer to S511 and S512 of FIG. 6 .

In the next process, an interlayer insulating layer 329 including a plurality of contact holes is disposed on the first surface of the buffer layer 312 (S950). The second contact hole 329h4 , the third contact hole 329h3 , the fourth contact hole 329h2 , and the fifth contact hole 329h1 may be disposed in the interlayer insulating layer 329 . See S521 of FIG. 7 .

Then, the first source-drain electrode 311b and the second source-drain electrode 311a are disposed on the interlayer insulating layer 329 (S960).

Looking at these contact holes in more detail, it is as shown in S522 of FIG. 7 . That is, the first source-drain electrode 311b is electrically connected to the light sensing unit of the diode region through the second contact hole 329h4, and is connected to the second electrode unit 325b of the light sensing unit.

The first source-drain electrode 311b is electrically connected to the light blocking layer 311a of the transistor region through the third contact hole 329h3. The first source-drain electrode 311b is electrically connected to the conductive region 320c in the transistor region in the fourth contact hole 329h2.

In addition, the second source-drain electrode 331a is electrically connected to the conductive region 320a of the transistor region through the fifth contact hole 329h1.

In FIG. 7, a plurality of contact holes are disposed using one mask, and source-drain electrodes 331a and 331b, the second electrode portion 325b, conductive regions 320c and 320a of the transistor, and light blocking Since the layer 311a is implemented in one process (source-drain electrode arrangement process, S960), process efficiency can be increased.

Thereafter, a protective layer 335 including a sixth contact hole 335h exposing the second source-drain electrode 331a is disposed on the first surface of the base substrate 303 (S970). Then, a pixel electrode 341 electrically connected to the second source-drain electrode 331a through the sixth contact hole 335h is disposed (S980). See Figures 8 and 9. Thereafter, the photo conversion unit is placed on the second surface of the base substrate 303 (S990) to complete the manufacturing process of the digital X-ray detector substrate. The light conversion unit 350 is shown in FIGS. 3 and 4 to be disposed on the second surface of the base substrate 303 .

Referring to FIG. 10 , a method for manufacturing a digital x-ray detector is provided by using a first surface divided into a plurality of photo-sensing pixel areas and a second surface that is a back surface of the first surface to correspond to the pixel areas on the first surface of the base substrate. Disposing a light blocking layer and a bias electrode, disposing a photo-sensing unit on the first surface, disposing a transistor element on the first surface after disposing the photo-sensing unit, and disposing a photo-conversion unit on the second surface. include

When the X-ray detector is manufactured and used according to the structure and process discussed so far, the bias electrode 311b and the light blocking layer 311a are simultaneously disposed in the process of processing the oxide transistor and the diode element in the process, and the second electrode unit 325b ) and the gate electrode 325a are disposed at the same time, the four masks can be reduced to two masks.

In addition, the IGZO deposition process after depositing the PIN diode can minimize the damage to the oxide element caused by hydrogen. The structure that shields the X-ray can reduce the damage of the oxide element.

Although the above has been described based on the embodiments of the present invention, various changes or modifications may be made at the level of those skilled in the art. Accordingly, it will be understood that such changes and modifications are included within the scope of the present invention as long as they do not depart from the scope of the present invention.

1: digital x-ray detector 10: bias driver
20: gate driver 30: readout integrated circuit
300: Substrate for digital X-ray detector 303: Base substrate
350: light conversion unit

Claims (17)

a base substrate including a first surface divided into a plurality of photo-sensing pixel areas and a second surface on which a photo-conversion unit is disposed on a rear surface of the first surface;
a light blocking layer and a bias electrode disposed in the pixel area on the first surface of the base substrate;
a buffer layer disposed on the light blocking layer and the bias electrode;
a plurality of transistors disposed in transistor regions of the plurality of pixel regions of the buffer layer, respectively;
a plurality of light sensing units disposed in diode regions of the plurality of pixel regions of the buffer layer and including a first electrode unit, a PIN layer, and a second electrode unit;
a first source-drain electrode connecting the transistor of the pixel area and the photo-sensing unit;
a second source-drain electrode connecting the transistor of the pixel region and a pixel electrode;
the transistor
an active layer having a conductive region and a semiconductor region on the buffer layer;
a gate insulating layer disposed on the active layer;
It includes a gate electrode disposed on the gate insulating film,
The first source-drain electrode electrically connects the conductive first region of the active layer and the second electrode,
The first source-drain electrode is electrically connected to the light blocking layer, a substrate for a digital X-ray detector.
According to claim 1,
The first electrode unit is disposed on the buffer layer and is electrically connected to the bias electrode through a contact hole formed in the buffer layer.
According to claim 1,
The second electrode part is made of the same material as the gate electrode of the transistor.
delete delete According to claim 1,
The substrate for a digital X-ray detector, wherein the light conversion unit further comprises a scintillator disposed directly on a second surface of the base substrate.
a base substrate comprising a first surface divided into a plurality of photo-sensing pixel areas and having a plurality of transistors and a plurality of photo-sensing units disposed thereon, and a second surface that is a rear surface of the first surface;
a light conversion unit disposed on the second surface; and
In the digital x-ray detector including a control circuit unit for controlling the transistor and the light sensing unit on the first surface,
a light blocking layer and a bias electrode disposed in the pixel area on the first surface of the base substrate;
a buffer layer disposed on the light blocking layer and the bias electrode;
the plurality of transistors disposed in transistor regions of the plurality of pixel regions of the buffer layer, respectively;
the plurality of light sensing units disposed in diode regions of the plurality of pixel regions of the buffer layer and including a first electrode unit, a PIN layer, and a second electrode unit;
a first source-drain electrode connecting the transistor of the pixel area and the photo-sensing unit; and
a second source-drain electrode connecting the transistor of the pixel area and a pixel electrode controlling the pixel area;
the transistor
an active layer having a conductive region and a semiconductor region on the buffer layer;
a gate insulating layer disposed on the active layer; and
It includes a gate electrode disposed on the gate insulating film,
The first source-drain electrode electrically connects the conductive first region of the active layer and the second electrode,
The first source-drain electrode is electrically connected to the light blocking layer, digital x-ray detector.
delete According to claim 7,
The first electrode part is disposed on the buffer layer and is electrically connected to the bias electrode through a contact hole formed in the buffer layer.
The second electrode part is made of the same material as the gate electrode of the transistor.
delete delete According to claim 7,
The digital X-ray detector of claim 1 , wherein the optical conversion unit further includes a scintillator disposed directly on a second surface of the base substrate.
disposing a light blocking layer and a bias electrode corresponding to the pixel areas on a first surface of a base substrate including a first surface divided into a plurality of photo-sensing pixel areas and a second surface that is a rear surface of the first surface;
disposing a buffer layer including a first contact hole exposing a portion of the bias electrode on the first surface;
disposing a light sensing unit on the buffer layer in a diode area of the pixel area;
disposing a transistor on the buffer layer in a transistor region of the pixel region;
disposing an interlayer insulating layer including a second contact hole, a third contact hole, a fourth contact hole, and a fifth contact hole on the first surface;
disposing a first source-drain electrode and a second source-drain electrode on the interlayer insulating layer;
disposing a protective layer including a sixth contact hole exposing the second source-drain electrode on the first surface;
disposing a pixel electrode electrically connected to the second source-drain electrode through the sixth contact hole; and
A method of manufacturing a substrate for a digital X-ray detector comprising the step of disposing a light conversion unit on the second surface.
According to claim 13,
The first source-drain electrode is electrically connected to the photo-sensing part of the diode region through the second contact hole,
the first source-drain electrode is electrically connected to the light blocking layer of the transistor region through the third contact hole;
The method of claim 1 , wherein the first source-drain electrode is electrically connected to a conductive region of the transistor region through the fourth contact hole.
According to claim 13,
wherein the second source-drain electrode is electrically connected to a conductive region of the transistor region through the fifth contact hole.
According to claim 13,
The step of arranging the light sensing unit is
disposing a first electrode part electrically contacting the bias electrode in the first contact hole in the diode region;
disposing a P (Positive) semiconductor layer on the first electrode part;
Disposing an I (Intrinsic) type semiconductor layer on the P (Positive) semiconductor layer; and
A method of manufacturing a substrate for a digital X-ray detector comprising the step of disposing an N (Negative) semiconductor layer on the I (Intrinsic) type semiconductor layer.
According to claim 16,
After the step of disposing the N (Negative) semiconductor layer
disposing an active layer in the transistor region;
disposing a gate insulating film on a portion of the active layer;
Disposing a gate electrode on the gate insulating film and simultaneously disposing a second electrode part on the N (Negative) semiconductor layer with the same material as the gate electrode; and
and doping and conducting a region of the active layer where the gate electrode is not disposed.

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