KR20100001639A - Substrate apparatus of digital radioactive ray image detector and manufacture method thereof - Google Patents

Abstract

PURPOSE: A substrate apparatus of a digital radioactive ray image detector and a manufacture method thereof are provided to detect in image with high sensitivity using the low amount of radiation. CONSTITUTION: A first optical conductive layer(110) is formed on the upper side of a thin film transistor substrate(100). An insulating layer(130) is formed on the upper side of the first optical conductive layer. A second optical conductive layer(140) is formed on the upper side of the insulating layer. The second optical conductive layer is charged between the insulating layers. The second optical conductive layer generates the electronics by radiating the radiation. A top electrode layer(150) is connected to an external power supply unit so that the first electrical field is formed inside the second optical conductive layer.

Description

Substrate Apparatus of Digital Radioactive ray Image Detector and Manufacture Method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radiation image detector, and more particularly, to a substrate device of a digital radiation image detector having an electrode for obtaining avalanche gain and a method of manufacturing the same.

The digital radiographic image detector is an apparatus for electrically detecting radiation such as X-rays transmitted through a human body or an object without a film to acquire image information. That is, by converting the image information obtained by irradiating radiation into an electrical signal and detecting it, it is possible to check whether there is an abnormality in the skeleton or organ of the human body or the crack of an object.

In general, a digital radiation image detector may be classified into a direct conversion method and an indirect conversion method according to a method of converting radiation energy transmitted through a human body or an object into an electrical signal. The indirect conversion method has a disadvantage in that a lot of loss and noise occurs in the energy conversion process, the direct conversion method is the latest technology.

On the other hand, since radiation is harmful to the human body, it is most preferable to irradiate a small amount of radiation and obtain a clear image even if possible. To this end, even if a small amount of radiation is irradiated by increasing the amount of signal generated by amplifying the resulting electrical signal can increase the sensitivity.

As a method for improving the photosensitivity performance, there has been disclosed a structure in which a photoconductive layer formed on the substrate of the detector is formed to have a thickness of several hundred μm or more in order to increase the absorption of incident radiation in the case of the direct method. As another method, a method of amplifying an electrical signal has been disclosed by generating an avalanche effect by forming an electrode applying a voltage in the middle of the photoconductive layer to amplify the electrical signal.

However, in order to increase the amount of radiation absorption, a high electric field must be applied by applying a few kV DC voltage in order to detect the amount of electric signal generated in the photoconductive layer. There is a fear that devices such as IC chips for readout may be damaged.

In order to form an electrode in the middle of the photoconductive layer in order to generate an avalanche effect, an insulating layer having a height of 10-30 μm must first be formed to install the electrode, and it is very difficult to form such a structure in the semiconductor process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate device for a digital radiation image detector having improved photosensitivity and a method of manufacturing the same, which are derived from the above background.

In addition, an object of the present invention is to facilitate a substrate device fabrication process of a digital radiation image detector for forming an avalanche gain.

According to the present invention, a thin film transistor (TFT) substrate; A first photoconductive layer formed on an upper surface of the thin film transistor substrate; An insulating layer formed in a lattice shape on an upper surface of the first photoconductive layer; A second photoconductive layer formed on an upper surface of the insulating layer, the second photoconductive layer being formed to fill a gap between the lattice of the insulating layer, and generating an electron and an electron pair by radiation; And an upper electrode layer formed on an upper surface of the second photoconductive layer and connected to an external power supply device so that a first electric field is formed inside the second photoconductive layer. Achieved by the device.

In this case, the method may further include a second insulating layer formed between the second photoconductive layer and the upper electrode layer.

The insulating layer includes an electrode inserted therein, wherein the electrode forms a second electric field stronger than the first electric field between the lattice of the insulating layer. The second electric field is also for forming an avalanche gain region.

On the other hand, the technical problem is a step of laminating a first photoconductive layer on a thin film transistor (TFT) substrate according to the present invention; Stacking a lower insulating layer on an upper surface of the first photoconductive layer; Stacking an electrode layer on an upper surface of the insulating layer; Etching in the form of a waffle so that the electrode layer is left in the form of a partition; Stacking an upper insulating layer on an upper surface of the etched electrode layer; Etching portions of the lower insulating layer and the upper insulating layer that are not in contact with the electrode layer; And laminating a second photoconductive layer. It is also achieved by a method of manufacturing a radiographic image sensor substrate device.

According to the present invention, there is an effect that the manufacturing process of the substrate device of the digital radiation image detector that can obtain the avalanche gain can be made easier. Accordingly, a substrate device of a digital radiation image detector capable of detecting an image having high sensitivity even with a low radiation dose can be provided.

The foregoing and further aspects of the present invention will become apparent from the following examples. Hereinafter, with reference to the preferred embodiments described with reference to the accompanying drawings of the present invention will be described in detail so that those skilled in the art can easily understand and implement.

1A is a block diagram of a substrate device of a digital radiation image detector according to an embodiment of the present invention.

As illustrated, the substrate device of the radiation image detector according to the present invention includes a TFT substrate 100, a first photoconductive layer 110, an insulating layer 130, and an electrode 135 inserted into the insulating layer 130. 2 photoconductive layer 140, and the upper electrode layer 150.

The TFT (Thin Film Transistor) substrate 100 includes a drain terminal, a source terminal, and a gate terminal connected to a capacitor for charge charging. In this embodiment, the TFT substrate 100 physically serves as a support.

The first photoconductive layer 110 is formed on the top surface of the TFT substrate 100. In the present embodiment, the first photoconductive layer 110 may be a compound of amorphous selenium containing amorphous selenium (A-Se) or As 2 Se 3 or As. The first photoconductive layer 110 is first formed on the upper surface of the TFT substrate 100, and the insulating layer 130, which will be described later, is laminated on the upper surface of the first photoconductive layer 110. It is not necessary to form it in the thickness of about 30 micrometers. That is, by first forming the first photoconductive layer 110 on the upper surface of the TFT substrate 100 and laminating an insulating layer thereon for electrode insertion, the thickness of the insulating layer 130 can be reduced, and the substrate device The production process can be facilitated.

The insulating layer 130 is formed on the upper surface of the first photoconductive layer 110. By stacking the insulating layer 130, noise that may be generated when the electrode 135, which will be described later, directly contacts the first photoconductive layer 110 may be removed. In this embodiment, the insulating layer 130 may be one of SiNx, BCB (Benzocyclobutane), SiO 2, polyimide, and photoacryl. However, the present invention is not limited thereto and encompasses obvious modifications.

The electrode 135 inserted into the insulating layer 130 forms a second electric field that is larger in size than the electric field generated by the upper electrode layer 150, and thus the flow intensity of holes to be filled in the TFT substrate 100. May cause an avalanche effect to be amplified.

The second photoconductive layer 140 generates charge and hole pairs from the radiation incident from the upper side. In the present embodiment, the second photoconductive layer 140 may be a compound of amorphous selenium containing amorphous selenium (a-Se) or As 2 Se 3 or As.

That is, although the first photoconductive layer 110 and the second photoconductive layer 140 are divided according to the stacked steps in the process, they may actually be the same material.

The upper electrode layer 150 is connected to an external power supply device. The flow of electrons and holes separated in the second photoconductive layer 140 may be induced by the voltage of the upper electrode layer 150. As a result, an electric field is formed.

1B is a block diagram of a substrate device of a digital radiation image detector according to another embodiment of the present invention. As shown in the drawing, the semiconductor device further includes a second insulating layer 200 formed between the second photoconductive layer 140 and the upper electrode layer 150. The second insulating layer 200 may remove noise that may be generated when the upper electrode layer 150 contacts the second photoconductive layer 140. In the present embodiment, the second insulating layer 200 may be implemented with a parylene coating layer. However, the present invention is not limited thereto and encompasses obvious modifications.

On the other hand, the second insulating layer 210 is formed when taking a still image. For example, when photographing a digital image with a plurality of frames while rotating around the human body, as shown in FIG. 1A, the second insulating layer 200 may not be formed.

FIG. 2 is a perspective view of a form in which the insulating layer 130 of FIG. 1A is formed.

As shown in FIG. 2, the insulating layer 130 is formed in a lattice form on the upper side of the TFT substrate. In this case, the electrode 135 is formed inside the insulating layer 130.

Figure 3 is an illustration of the electric field shape in the avalanche gain region in accordance with the present invention. As shown in FIG. 3, the first electric field 30a is formed by the upper electrode layer. The charge formed in the second photoconductive layer 140 is accelerated by the second electric field 30b formed by the electrode 135 and amplified in the first photoconductive layer 110. Referring to FIG. 3, it can be seen that the density of the electric field line with respect to the first electric field 30a is higher by the second electric field 30b formed between the electrodes 135. The signals thus amplified are stacked on the TFT substrate 100, thereby producing an avalanche effect. Accordingly, it is possible to provide a radiographic image detector having high light sensitivity even with a small radiation dose.

4 is a flowchart of a method of manufacturing a digital radiation image detector substrate device according to an embodiment of the present invention.

First, a first photoconductive layer is laminated on a TFT substrate serving as a physical support (S300). In the present embodiment, the first photoconductive layer may be a compound of amorphous selenium (a-Se) or amorphous selenium containing As 2 Se 3 or As. And a lower insulating layer is laminated thereon (S310). In this case, the lamination may be performed through a deposition process. And an electrode layer is stacked thereon (S320). The electrode layer is configured for the avalanche effect. Thereafter, the electrode layer is etched in a waffle shape so as to remain in a lattice shape (S330).

After that, the upper insulating layer is laminated again on the electrode (S340). In operation S350, the lower insulating layer and the upper insulating layer portion of the portion not in contact with the electrode layer are etched.

At this time, the first photoconductive layer is etched between the lattice in which the lower electrode layer and the upper electrode layer are etched. In addition, the first photoconductive layer may be further etched together with the lower electrode layer and the upper electrode layer during etching, so that the thin film film transistor substrate may be exposed between the lattice in which the lower electrode layer and the upper electrode layer are etched.

That is, it is etched so that an insulating layer remains like the lattice form in which the electrode was left. The second photoconductive layer is stacked thereon (S360). In this embodiment, the second photoconductive layer is amorphous selenium (a-Se).

That is, the electrode insertion process for the avalanche effect can be facilitated by first inserting an electrode for deriving the avalanche effect in a state in which the first photoconductive layer is laminated.

In an exemplary embodiment, a second insulating layer is subsequently stacked on the second photoconductive layer (S370). The second insulating layer is for removing noise that may be generated when the second photoconductive layer and the upper electrode layer to be laminated thereafter are in contact. In operation S380, an upper electrode layer is stacked on the second insulating layer.

However, at this time, the step of stacking the second insulating layer on the second photoconductive layer is not essential, and it is also possible to stack the upper electrode layer directly on the second photoconductive layer.

So far I looked at the center of the preferred embodiment for the present invention.

Those skilled in the art will understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

1A is a block diagram of a substrate device of a digital radiation image detector according to an embodiment of the present invention;

1B is a block diagram of a substrate device of a digital radiation image detector according to another embodiment of the present invention;

FIG. 2 is a perspective view of a form in which the insulating layer 130 of FIG. 1A is formed.

3 is an illustration of the electric field form in the avalanche gain region in accordance with the present invention;

4 is a flowchart of a method of manufacturing a digital radiation image detector substrate device according to an embodiment of the present invention.

Claims (10)

Thin film transistor (TFT) substrates; A first photoconductive layer formed on an upper surface of the thin film transistor substrate; An insulating layer formed in a lattice shape on an upper surface of the first photoconductive layer; A second photoconductive layer formed on an upper surface of the insulating layer, the second photoconductive layer being formed to fill a gap between the lattice of the insulating layer, and generating an electron and an electron pair by the irradiated radiation; And And an upper electrode layer formed on an upper surface of the second photoconductive layer and connected to an external power supply device so that a first electric field is formed inside the second photoconductive layer. . The method of claim 1, And a second insulating layer formed between the second photoconductive layer and the upper electrode layer. The method according to claim 1 or 2, The insulating layer includes an electrode inserted therein, wherein the electrode forms a second electric field stronger than the first electric field between the gratings of the insulating layer. The method of claim 3, And said second electric field is for forming an avalanche gain region. The substrate apparatus of claim 1 or 2, wherein the first photoconductive layer or the second photoconductive layer is amorphous selenium or a compound thereof. Depositing a first photoconductive layer on a thin film transistor (TFT) substrate; Stacking a lower insulating layer on an upper surface of the first photoconductive layer; Stacking an electrode layer on an upper surface of the insulating layer; Etching in the form of a waffle so that the electrode layer is left in the form of a partition; Stacking an upper insulating layer on an upper surface of the etched electrode layer; Etching portions of the lower insulating layer and the upper insulating layer that are not in contact with the electrode layer; And Stacking a second photoconductive layer; and a method of manufacturing a radiographic image detector substrate device. The method of claim 6, The etching may include etching the first photoconductive layer to be exposed between the lattice in which the lower electrode layer and the upper electrode layer are etched. The method of claim 6, The etching may include etching the thin film transistor substrate to be exposed between the lattice in which the lower electrode layer and the upper electrode layer are etched. The method according to any one of claims 6 to 8, And laminating a second insulating layer after the laminating of the second photoconductive layer. The method of claim 6, wherein the first photoconductive layer or the second photoconductive layer is amorphous selenium or a compound thereof.

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