Radiation detection and method of manufacturing a radiation detector
阅读说明:本技术 辐射检测和制造辐射检测器的方法 (Radiation detection and method of manufacturing a radiation detector ) 是由 梁魁 于 2019-06-28 设计创作,主要内容包括:提供了一种具有多个像素的辐射检测器。多个像素中的对应一个包括:薄膜晶体管,其位于衬底基板上;层间介电层,其位于薄膜晶体管的远离衬底基板的一侧;感应电极和偏压电极,其位于层间介电层的远离衬底基板的一侧,其中,感应电极贯穿层间介电层以电连接至薄膜晶体管;钝化层,其位于感应电极和偏压电极的远离层间介电层的一侧,其中,钝化层包括第一部分和第二部分;以及,辐射检测层,其位于钝化层的远离衬底基板的一侧。第一部分和第二部分形成实质上平坦的接触表面。(A radiation detector having a plurality of pixels is provided. A corresponding one of the plurality of pixels includes: a thin film transistor on the substrate base plate; the interlayer dielectric layer is positioned on one side of the thin film transistor, which is far away from the substrate base plate; the sensing electrode and the bias electrode are positioned on one side of the interlayer dielectric layer far away from the substrate base plate, wherein the sensing electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor; a passivation layer on a side of the sensing electrode and the bias electrode away from the interlayer dielectric layer, wherein the passivation layer includes a first portion and a second portion; and the radiation detection layer is positioned on one side of the passivation layer far away from the substrate base plate. The first portion and the second portion form a substantially planar contact surface.)
1. A radiation detector having a plurality of pixels, wherein a corresponding one of the plurality of pixels comprises:
a thin film transistor on the substrate base plate;
the interlayer dielectric layer is positioned on one side of the thin film transistor, which is far away from the substrate base plate;
a sensing electrode and a bias electrode on a side of the interlayer dielectric layer remote from the substrate, wherein the sensing electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor;
a passivation layer on a side of the sensing electrode and the biasing electrode away from the interlayer dielectric layer, wherein the passivation layer includes a first portion and a second portion; and
a radiation detection layer located on a side of the passivation layer remote from the substrate base plate;
wherein the first portion comprises a first insulating material;
the second portion comprises a second insulating material different from the first insulating material; and is
A first surface of the first portion distal from the base substrate and a second surface of the second portion distal from the base substrate are substantially coplanar, forming a substantially planar contact surface.
2. The radiation detector according to claim 1, wherein the second portion substantially covers an edge portion of the sensing electrode and substantially covers an edge portion of the biasing electrode;
the first portion substantially covers a non-edge portion of the sense electrode that is substantially surrounded by the edge portion of the sense electrode and substantially covers a non-edge portion of the bias electrode that is substantially surrounded by the edge portion of the bias electrode; and is
The first portion is not in direct contact with the edge portion of the sense electrode and the edge portion of the bias electrode.
3. The radiation detector according to claim 1, wherein the first portion and the second portion are complementary to each other.
4. The radiation detector according to claim 3, wherein a portion of the first portion has a substantially inverted trapezoidal shape in a cross section perpendicular to a plane of the substrate base plate and the radiation detection layer; and is
A portion of the second portion has a substantially trapezoidal shape in a cross section perpendicular to a plane of the substrate base plate and the radiation detection layer.
5. The radiation detector according to any one of claims 1 to 4, wherein the first insulating material is an organic polymer insulating material; and is
The second insulating material is an inorganic insulating material.
6. The radiation detector according to any one of claims 1 to 5, wherein the first portion and the second portion together form a continuous insulating layer; and is
The surface of the continuous insulating layer remote from the base substrate is substantially uniform in height relative to the base substrate.
7. The radiation detector according to any one of claims 1 to 6, wherein an orthographic projection of the first portion on the substrate base plate at least partially overlaps an orthographic projection of the sensing electrode on the substrate base plate and at least partially overlaps an orthographic projection of the biasing electrode on the substrate base plate.
8. The radiation detector according to any one of claims 1 to 6, wherein an orthographic projection of the second portion on the substrate base plate completely covers an orthographic projection of the sensing electrode on the substrate base plate and completely covers an orthographic projection of the biasing electrode on the substrate base plate;
the second portion spaces the bias electrode from the first portion; and is
The second portion spaces the sensing electrode from the first portion.
9. The radiation detector according to any one of claims 1 to 7, wherein the second portion substantially covers an inter-electrode area between the sensing electrode and the bias electrode.
10. The radiation detector according to any one of claims 1-7 and claim 9, wherein the sensing electrodes and the biasing electrodes are interdigitated electrodes;
the branches of the sensing electrode and the bias electrode are alternately arranged;
the first portion includes interdigitated branches;
the orthographic projection of the sensing electrode and the bias electrode on the substrate baseplate substantially covers the orthographic projection of the first part on the substrate baseplate; and is
The second portion covers an inter-electrode area between the interdigitated branches of the first portion.
11. The radiation detector according to any one of claims 1 to 10, wherein the radiation detection layer is in direct contact with the first portion and in direct contact with the second portion; and is
The first surface of the first portion distal from the base substrate and the second surface of the second portion distal from the base substrate are substantially coplanar, forming the substantially planar contact surface in direct contact with the radiation-detecting layer.
12. The radiation detector according to any one of claims 1 to 10, wherein the passivation layer further comprises: a third portion located on a side of the first and second portions remote from the substrate base plate; and is
The third portion is in direct contact with the radiation detection layer.
13. The radiation detector according to any one of claims 1 to 12, wherein the thickness of the sensing electrode and the biasing electrode in a direction from the substrate base plate to the radiation detection layer is greater than 75 nm.
14. The radiation detector according to any one of claims 1 to 13, wherein a thickness of the first portion and the second portion in a direction from the substrate base plate to the radiation detection layer is in a range of 100nm to 300 nm.
15. A method of manufacturing a radiation detector having a plurality of pixels, wherein forming a corresponding one of the plurality of pixels comprises:
forming a thin film transistor on a substrate;
forming an interlayer dielectric layer on one side of the thin film transistor far away from the substrate base plate;
forming a sensing electrode and a bias electrode on one side of the interlayer dielectric layer far away from the substrate, wherein the sensing electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor;
forming a passivation layer on a side of the sensing electrode and the biasing electrode away from the interlayer dielectric layer, wherein forming the passivation layer includes forming a first portion and forming a second portion; and
forming a radiation detection layer on one side of the passivation layer far away from the substrate base plate;
wherein the first portion comprises a first insulating material;
the second portion comprises a second insulating material different from the first insulating material; and is
A first surface of the first portion distal from the base substrate and a second surface of the second portion distal from the base substrate are substantially coplanar, forming a substantially planar contact surface.
16. The method of claim 15, wherein forming the passivation layer comprises:
forming a second insulating material layer on one sides of the induction electrode and the bias electrode, which are far away from the substrate base plate;
patterning the second layer of insulating material to form the second portion, wherein a portion of the second layer of insulating material is removed during patterning to expose a surface of the sense electrode and a surface of the bias electrode; and
forming a first layer of insulating material covering the surface of the sense electrode and the surface of the bias electrode exposed during patterning on a side of the second portion remote from the substrate base plate.
17. The method of claim 16, further comprising: reducing a thickness of the first layer of insulating material to form the first portion.
18. The method of claim 16, wherein reducing the thickness of the first layer of insulating material is performed such that a first surface of the first portion distal from the base substrate and a second surface of the second portion distal from the base substrate are substantially coplanar, thereby forming the substantially planar contact surface in direct contact with the radiation-detecting layer.
19. The method of claim 18, wherein the second portion is formed to cover an edge portion of the sense electrode, an edge portion of the bias electrode, and an inter-electrode area between the sense electrode and the bias electrode; and is
Removing portions of the second insulating material layer during patterning that correspond to non-edge portions of the sense electrode that are substantially surrounded by the edge portions of the sense electrode and non-edge portions of the bias electrode that are substantially surrounded by the edge portions of the bias electrode, respectively.
20. The method of any one of claims 15 to 19, wherein forming the sense electrode and the bias electrode comprises:
forming a conductive material layer on the interlayer dielectric layer; and
patterning the conductive material layer using a single mask to form interdigitated electrodes including the sensing electrodes and the bias electrodes;
wherein the branches of the sensing electrode and the bias electrode are alternately arranged; and is
Forming the layer of conductive material includes: depositing a conductive material on the interlayer dielectric layer to a thickness greater than 75nm in a direction from the interlayer dielectric layer to the substrate base plate.
Technical Field
The present invention relates to display technology, and more particularly, to radiation detection and methods of manufacturing radiation detectors.
Background
Direct conversion radiation detectors typically include a radiation receiver, a processor, and a power supply. Typically, the radiation receiver has a radiation detector made of Gd2O2A scintillation layer (S) made of S or CsI, a large area amorphous silicon sensor array and a readout circuit. The scintillation layer converts radiation (e.g., X-ray photons) into visible light. Subsequently, the large scale integrated amorphous silicon sensor array converts visible light into electrons and digitizes it by a readout circuit. The digitized signal is transmitted to a computer for image display.
Non-direct conversion radiation detectors typically include a material selected from Gd2O2A scintillation layer made of S or CsI, a PIN photodiode and a thin film transistor array. The scintillation layer converts radiation (e.g., X-ray photons) into visible light. The PIN photodiode converts visible light into an electric signal for image display.
Disclosure of Invention
In one aspect, the present invention provides a radiation detector having a plurality of pixels, wherein a corresponding one of the plurality of pixels comprises: a thin film transistor on the substrate base plate; the interlayer dielectric layer is positioned on one side of the thin film transistor, which is far away from the substrate base plate; the sensing electrode and the bias electrode are positioned on one side of the interlayer dielectric layer far away from the substrate base plate, wherein the sensing electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor; a passivation layer on a side of the sensing electrode and the bias electrode away from the interlayer dielectric layer, wherein the passivation layer includes a first portion and a second portion; and a radiation detection layer located on a side of the passivation layer remote from the substrate base plate; wherein the first portion comprises a first insulating material; the second portion comprises a second insulating material different from the first insulating material; and a first surface of the first portion distal from the substrate base and a second surface of the second portion distal from the substrate base are substantially coplanar, thereby forming a substantially planar contact surface.
Optionally, the second portion substantially covers an edge portion of the sensing electrode and substantially covers an edge portion of the biasing electrode; the first portion substantially covers a non-edge portion of the sense electrode that is substantially surrounded by an edge portion of the sense electrode and substantially covers a non-edge portion of the bias electrode that is substantially surrounded by an edge portion of the bias electrode; and, the first portion is not in direct contact with the edge portion of the sensing electrode and the edge portion of the biasing electrode.
Optionally, the first portion and the second portion are complementary to each other.
Optionally, a portion of the first portion has a substantially inverted trapezoidal shape in a cross section perpendicular to a plane of the substrate base plate and the radiation detection layer; and a part of the second portion has a substantially trapezoidal shape in a cross section perpendicular to a plane of the substrate base plate and the radiation detection layer;
optionally, the first insulating material is an organic polymer insulating material; and, the second insulating material is an inorganic insulating material.
Optionally, the first portion and the second portion together form a continuous insulating layer; and the surface of the continuous insulating layer remote from the base substrate is substantially uniform in height relative to the base substrate.
Optionally, an orthographic projection of the first portion on the substrate base plate at least partially overlaps an orthographic projection of the sensing electrode on the substrate base plate and at least partially overlaps an orthographic projection of the bias electrode on the substrate base plate.
Optionally, the orthographic projection of the second part on the substrate base plate completely covers the orthographic projection of the sensing electrode on the substrate base plate and completely covers the orthographic projection of the biasing electrode on the substrate base plate; the second portion spacing the biasing electrode from the first portion; and the second portion spaces the sensing electrode from the first portion.
Optionally, the second portion substantially covers an inter-electrode area between the sensing electrode and the bias electrode.
Optionally, the sensing electrodes and the biasing electrodes are interdigitated electrodes; the branches of the induction electrode and the bias electrode are alternately arranged; the first portion includes interdigitated branches; the orthographic projection of the sensing electrode and the bias electrode on the substrate substantially covers the orthographic projection of the first part on the substrate; and the second portion covers the inter-electrode area between the interdigitated branches of the first portion.
Optionally, the radiation detection layer is in direct contact with the first portion and in direct contact with the second portion; and a first surface of the first portion remote from the substrate base plate and a second surface of the second portion remote from the substrate base plate are substantially coplanar, thereby forming a substantially planar contact surface in direct contact with the radiation detection layer.
Optionally, the passivation layer further comprises: a third portion located on a side of the first and second portions remote from the substrate base; and the third portion is in direct contact with the radiation detection layer.
Optionally, the sensing electrode and the bias electrode have a thickness in a direction from the substrate base plate to the radiation detection layer of more than 75 nm.
Optionally, the thickness of the first portion and the second portion in a direction from the substrate base plate to the radiation detection layer is in a range of 100nm to 300 nm.
In another aspect, the present invention provides a method of manufacturing a radiation detector having a plurality of pixels, wherein forming a corresponding one of the plurality of pixels includes: forming a thin film transistor on a substrate; forming an interlayer dielectric layer on one side of the thin film transistor, which is far away from the substrate base plate; forming an induction electrode and a bias electrode on one side of the interlayer dielectric layer far away from the substrate, wherein the induction electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor; forming a passivation layer on the sides of the sensing electrode and the bias electrode away from the interlayer dielectric layer, wherein forming the passivation layer comprises forming a first portion and forming a second portion; and forming a radiation detection layer on one side of the passivation layer away from the substrate base plate; wherein the first portion comprises a first insulating material; the second portion comprises a second insulating material different from the first insulating material; and a first surface of the first portion distal from the substrate base and a second surface of the second portion distal from the substrate base are substantially coplanar, thereby forming a substantially planar contact surface.
Optionally, forming the passivation layer comprises: forming a second insulating material layer on one side of the induction electrode and the bias electrode, which is far away from the substrate base plate; patterning the second layer of insulating material to form a second portion, wherein a portion of the second layer of insulating material is removed during the patterning to expose a surface of the sense electrode and a surface of the bias electrode; and forming a first insulating material layer covering a surface of the sensing electrode and a surface of the bias electrode exposed during the patterning on a side of the second portion away from the substrate base plate.
Optionally, the method further comprises: the thickness of the first layer of insulating material is reduced to form the first portion.
Optionally, reducing the thickness of the first layer of insulating material is performed such that a first surface of the first portion remote from the base substrate and a second surface of the second portion remote from the base substrate are substantially coplanar, thereby forming a substantially flat contact surface in direct contact with the radiation detection layer.
Optionally, the second portion is formed to cover an edge portion of the sensing electrode, an edge portion of the bias electrode, and an inter-electrode area between the sensing electrode and the bias electrode; and, portions of the second insulating material layer corresponding to non-edge portions of the sensing electrode and the biasing electrode, respectively, substantially surrounded by edge portions of the sensing electrode and the biasing electrode, are removed during the patterning.
Optionally, forming the sensing electrode and the bias electrode comprises: forming a conductive material layer on the interlayer dielectric layer; patterning the conductive material layer by using a single mask plate to form an interdigital electrode comprising an induction electrode and a bias electrode; wherein the branches of the induction electrode and the bias electrode are alternately arranged; and, forming the conductive material layer includes: a conductive material is deposited on the interlayer dielectric layer to a thickness greater than 75nm in a direction from the interlayer dielectric layer to the substrate base plate.
Drawings
The following drawings are merely exemplary for purposes of illustrating various embodiments in accordance with the disclosure and are not intended to limit the scope of the invention.
Fig. 1 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure.
Fig. 2 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 3 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 4 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure.
Fig. 5 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 6 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 7 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure.
Fig. 8 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 9 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 10 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure.
Fig. 11 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 12 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure.
Fig. 13 is a plan view of a sense electrode and a bias electrode in some embodiments according to the present disclosure.
Fig. 14 is a plan view of a passivation layer in some embodiments according to the present disclosure.
Fig. 15 is a plan view of a passivation layer in some embodiments according to the present disclosure.
Fig. 16 compares dark current in a conventional radiation detector and in a radiation detector according to some embodiments of the present disclosure, respectively.
Fig. 17 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure.
Fig. 18A-18E illustrate methods of manufacturing a radiation detector in some embodiments according to the present disclosure.
Detailed Description
The present disclosure will now be described more specifically with reference to the following examples. It is noted that the following description of some embodiments is presented for purposes of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.
In some embodiments, the radiation detector includes a sensing electrode S and a biasing electrode B on the interlayer dielectric layer and a polyimide layer on the sensing electrode S and the biasing electrode B. In the present disclosure, it was found that it is generally desirable to make the polyimide layer relatively thin to allow carriers to pass through the polyimide layer at high charges. As a result, it is also necessary to make the electrodes relatively thin so as to be completely covered with the polyimide layer. In the present disclosure, it was found that radiation detectors having thin-layer metal electrodes are prone to defects such as bulges, oxidation, poor contacts, and cracks. These defects can further lead to short circuits and dark state leakage currents, affecting the performance of the radiation detector.
Accordingly, the present disclosure provides, among other things, a radiation detector and a method of manufacturing a radiation detector that substantially obviate one or more of the problems due to limitations and disadvantages of the related art. In one aspect, the present disclosure provides a radiation detector having a plurality of pixels. In some embodiments, a corresponding one of the plurality of pixels of the radiation detector comprises: a thin film transistor on the substrate base plate; the interlayer dielectric layer is positioned on one side of the thin film transistor, which is far away from the substrate base plate; the sensing electrode and the bias electrode are positioned on one side of the interlayer dielectric layer far away from the substrate base plate, wherein the sensing electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor; a passivation layer on a side of the sensing electrode and the bias electrode away from the interlayer dielectric layer, wherein the passivation layer includes a first portion and a second portion; and a radiation detection layer on a side of the passivation layer remote from the substrate base plate, wherein the radiation detection layer is in direct contact with the first portion and in direct contact with the second portion. Optionally, the first portion comprises a first insulating material; and the second portion comprises a second insulating material different from the first insulating material. Optionally, a first surface of the first portion remote from the substrate base plate and a second surface of the second portion remote from the substrate base plate are substantially coplanar, forming a substantially flat contact surface in direct contact with the radiation detection layer.
Fig. 1 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure. Referring to fig. 1, a corresponding one of the plurality of pixels of the radiation detector includes: a thin film transistor TFT on the
As used herein, the term "substantially coplanar" refers to two or more surfaces on a structure sharing the same common plane or being offset from sharing the same common plane by no more than 100nm (e.g., no more than 90nm, no more than 80nm, no more than 70nm, no more than 60nm, no more than 50nm, no more than 40nm, no more than 30nm, no more than 20nm, no more than 10nm, no more than 5nm, or no more than 1 nm). Alternatively, the term "substantially coplanar" refers to two or more surfaces on a structure sharing the same common plane or being offset from sharing the same common plane by no more than 20 nm.
As used herein, the term "substantially planar contact surface" refers to a planar surface (e.g., the entire surface is completely planar) or a surface having minor irregularities (e.g., slight variations and/or deviations in the geometry of the planar surface). Optionally, the deviation in planar surface geometry is no greater than 100nm (e.g., no greater than 90nm, no greater than 80nm, no greater than 70nm, no greater than 60nm, no greater than 50nm, no greater than 40nm, no greater than 30nm, no greater than 20nm, no greater than 10nm, no greater than 5nm, or no greater than 1 nm). Optionally, the deviation in the flat surface geometry is no greater than 20 nm.
In some embodiments,
Fig. 2 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Fig. 3 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Referring to fig. 1-3, in some embodiments, the
Referring to fig. 1-3, in some embodiments, the
Referring to fig. 1-3, in some embodiments, an orthographic projection of the
Fig. 7 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure. Fig. 8 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Fig. 9 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Referring to fig. 7-9, in some embodiments, the
Referring to fig. 7 to 9, in some embodiments, an orthographic projection of the
As described above and with reference to fig. 1 to 12, the first and
In some embodiments, the first insulating material is an organic insulating material and the second insulating material is an inorganic insulating material. Optionally, the first insulating material is an insulating material that allows carriers to pass under high charge and is substantially insulating under low charge.Examples of suitable insulating materials for making the
In some embodiments, the first insulating material is an inorganic insulating material and the second insulating material is an organic insulating material. Optionally, the first insulating material is an insulating material that can be deposited uniformly on the surface. Examples of suitable insulating materials for making the
The
As used herein, a "substantially trapezoidal shape" or "substantially inverted trapezoidal shape" may include a shape or geometry having a pair of substantially parallel sides and a pair of substantially non-parallel sides (whether the substantially parallel sides or the substantially non-parallel sides include straight lines or curved lines). As used herein, the term "substantially parallel sides" refers to two sides that form an included angle in the range of 0 degrees to 15 degrees (e.g., 0 degrees to 1 degree, 1 degree to 2 degrees, 2 degrees to 5 degrees, 5 degrees to 10 degrees, or 10 degrees to 15 degrees). As used herein, the term "substantially non-parallel sides" refers to two sides that form an included angle in a range greater than 15 degrees. Alternatively, the pair of substantially parallel sides of the substantially trapezoidal shape includes a short side and a long side, wherein the long side is closer to the bottom side of the
Fig. 4 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure. Fig. 5 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Fig. 6 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Fig. 10 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure. Fig. 11 is an enlarged view of a contact interface between a bias electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Fig. 12 is an enlarged view of a contact interface between a sensing electrode and a passivation layer in a radiation detector in some embodiments according to the present disclosure. Referring to fig. 4-6 and 10-12, in some embodiments, a portion (e.g., a branch or finger) of the
A variety of suitable materials may be used to fabricate the
The sensing electrode S and the biasing electrode B may be fabricated using various suitable electrode materials. Examples of suitable electrode materials for making the sensing electrode S and the biasing electrode B include, but are not limited to: silver nanoparticles, graphene, carbon nanotubes, molybdenum, aluminum, chromium, tungsten, titanium, tantalum, copper, and alloys or laminates containing them. Various suitable fabrication methods may be used to fabricate the sense electrode S and the bias electrode B. For example, the electrode material may be deposited on the substrate (e.g., by sputtering or vapor deposition or solution coating); and patterned (e.g., by photolithography such as a wet etch process) to form the sense electrode S and bias electrode B. Alternatively, the sensing electrode S and the bias electrode B may be spin coated on the substrate. Alternatively, the sensing electrode S and the biasing electrode B may have a thickness in a range of 50nm to 200nm (e.g., 50nm to 100nm, 100nm to 150nm, or 150nm to 200 nm). Alternatively, each of the sensing electrode S and the bias electrode B has a thickness of more than 75nm in a direction from the
Various suitable insulating materials and various suitable fabrication methods may be used to form the
Various suitable insulating materials and various suitable fabrication methods may be used to fabricate the
Various suitable radiation-detecting materials and various suitable fabrication methods may be used to fabricate the radiation-detecting
The sensing electrode S and the biasing electrode B may be fabricated in various suitable shapes. Fig. 13 is a plan view of a sense electrode and a bias electrode in some embodiments according to the present disclosure. Referring to fig. 13, in some embodiments, the sensing electrodes S and the biasing electrodes B are interdigitated electrodes. As used herein, the term "interdigitated electrode" indicates at least two electrodes, wherein the "branches" or "fingers" of each electrode are arranged in an alternating manner. For example, as shown in fig. 13, a pair of comb-like interdigital electrodes comprise "branches" that are arranged in an alternating manner with respect to each other. It should be understood that other shapes of electrodes are also suitable as interdigitated electrodes. Optionally, the interdigitated electrodes are at least two complementarily shaped electrodes. As shown in fig. 13, the branches Bs of the sensing electrode S and the branches Bb of the biasing electrode B are alternately arranged. Alternatively, the branch Bs of the sensing electrode S and the branch Bb of the biasing electrode B are substantially parallel to each other.
Fig. 14 is a plan view of a passivation layer in some embodiments according to the present disclosure. Referring to fig. 14, in some embodiments,
Fig. 15 is a plan view of a passivation layer in some embodiments according to the present disclosure. Referring to fig. 15, in some embodiments,
As shown in fig. 14 and 15, in some embodiments, the
In the present radiation detector, since at least the edge portion of the sensing electrode S and at least the edge portion of the bias electrode B are covered by one of the
Referring to fig. 1, 4, 7 and 10, in some embodiments, the radiation detector further comprises: and a
Fig. 16 compares dark current in a conventional radiation detector and in a radiation detector according to some embodiments of the present disclosure, respectively. Referring to fig. 16, the PI curves represent dark current in a conventional radiation detector in which the passivation layer is made entirely of a polyimide material; the GI + PI curve represents the dark current in a radiation detector according to the present disclosure, wherein the passivation layer comprises a first portion made of polyimide and a second portion made of silicon nitride. In both the conventional radiation detector and the radiation detector according to the present disclosure, the electrode thickness is about 50 nm. As shown in fig. 16, the dark current in the radiation detector according to the present disclosure is significantly lower than that in the conventional radiation detector. Furthermore, the electrical breakdown voltage of the passivation layer in the radiation detector according to the present disclosure is significantly higher compared to the electrical breakdown voltage in conventional radiation detectors.
Fig. 17 is a cross-sectional view of a pixel of a radiation detector in some embodiments according to the present disclosure. Referring to fig. 17, in some embodiments, the passivation layer further includes: a third portion 33 located on a side of the
In some embodiments, the third portion 33 has a substantially flat contact surface in direct contact with the radiation detection layer. As used herein, the term "substantially planar contact surface" refers to a planar surface (e.g., the entire surface is completely planar) or a surface having minor irregularities (e.g., slight variations and/or deviations in the geometry of the planar surface). Optionally, the deviation in planar surface geometry is no greater than 100nm (e.g., no greater than 90nm, no greater than 80nm, no greater than 70nm, no greater than 60nm, no greater than 50nm, no greater than 40nm, no greater than 30nm, no greater than 20nm, no greater than 10nm, no greater than 5nm, or no greater than 1 nm). Optionally, the deviation in the flat surface geometry is no greater than 20 nm.
In another aspect, the present disclosure provides a method of manufacturing a radiation detector having a plurality of pixels. In some embodiments, forming the corresponding one of the plurality of pixels comprises: forming a thin film transistor on a substrate; forming an interlayer dielectric layer on one side of the thin film transistor, which is far away from the substrate base plate; forming an induction electrode and a bias electrode on one side of the interlayer dielectric layer far away from the substrate, wherein the induction electrode penetrates through the interlayer dielectric layer to be electrically connected to the thin film transistor; forming a passivation layer on the sides of the sensing electrode and the bias electrode away from the interlayer dielectric layer, wherein forming the passivation layer comprises forming a first portion and forming a second portion; and forming a radiation detection layer on a side of the passivation layer away from the substrate base plate. Optionally, the radiation detection layer is in direct contact with the first portion and in direct contact with the second portion. Optionally, the first portion comprises a first insulating material; the second portion includes a second insulating material different from the first insulating material. Optionally, a first surface of the first portion remote from the substrate base plate and a second surface of the second portion remote from the substrate base plate are substantially coplanar, forming a substantially flat contact surface in direct contact with the radiation detection layer.
Fig. 18A-18E illustrate methods of manufacturing a radiation detector in some embodiments according to the present disclosure. Referring to fig. 18A, a second insulating material layer 32' is formed on the sides of the sensing electrode S and the biasing electrode B away from the
Referring to fig. 18C, after the
Referring to fig. 18D, the
Referring to fig. 18E, subsequently, a
Referring to fig. 13, in some embodiments, the step of forming the sensing electrode S and the biasing electrode B includes: forming a conductive material layer on the interlayer dielectric layer; and patterning the conductive material layer using a single mask to form interdigitated electrodes including sensing electrodes S and bias electrodes B. Alternatively, the branches of the sensing electrodes S and the biasing electrodes B are alternately arranged. Optionally, forming the layer of conductive material comprises: a conductive material is deposited on the interlayer dielectric layer to a thickness greater than 75nm in a direction from the interlayer dielectric layer to the substrate base plate.
Referring to fig. 18E, subsequently, a
Any suitable scintillation material may be used to fabricate
The foregoing descriptions of embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or exemplary embodiments disclosed. The foregoing description is, therefore, to be considered illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to explain the principles of the invention and its best mode practical application to enable one skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents, in which all terms are to be interpreted in their broadest reasonable sense unless otherwise indicated. Thus, the terms "invention," "present invention," and the like, do not necessarily limit the scope of the claims to particular embodiments, and references to exemplary embodiments of the invention do not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. Furthermore, these claims may refer to the use of the terms "first," "second," etc. followed by a noun or element. Such terms are to be understood as a meaning and not as a limitation on the number of elements modified by such a meaning unless a specific number is given. Any advantages and benefits described do not necessarily apply to all embodiments of the invention. It will be appreciated by those skilled in the art that changes may be made to the embodiments described without departing from the scope of the invention as defined by the appended claims. Furthermore, no element or component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the appended claims.