Thin film transistor, manufacturing method thereof, pressure sensor and pressure sensing device
阅读说明：本技术 薄膜晶体管、其制作方法、压力传感器及压力传感装置 (Thin film transistor, manufacturing method thereof, pressure sensor and pressure sensing device ) 是由 陶永春 曲峰 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种薄膜晶体管、其制作方法、压力传感器及压力传感装置,该薄膜晶体管包括：衬底基板,位于衬底基板上叠层设置的栅极和有源层,栅极和有源层之间具有空腔结构；空腔结构在衬底基板上的正投影至少覆盖有源层在衬底基板上的正投影。通过在栅极和有源层之间设置空腔结构,该空腔结构相当于薄膜晶体管的附加绝缘层,这样一来,当按压薄膜晶体管的栅极一侧,空腔结构的厚度则会发生变化,从而使得栅电容发生变化,进而能够使得薄膜晶体管的沟道电流发生变化,从而可以实现压力的信号测量,因此通过多个上述薄膜晶体管的连接和行列扫描处理,形成压力传感器,可以实现压力分布测试及触控功能的实现。(The invention discloses a thin film transistor, a manufacturing method thereof, a pressure sensor and a pressure sensing device, wherein the thin film transistor comprises: the substrate base plate is positioned on the grid electrode and the active layer which are arranged on the substrate base plate in a stacked mode, and a cavity structure is arranged between the grid electrode and the active layer; the orthographic projection of the cavity structure on the substrate at least covers the orthographic projection of the active layer on the substrate. Through setting up the cavity structure between grid and active layer, this cavity structure is equivalent to thin film transistor's additional insulating layer, so, when pressing thin film transistor's grid one side, the thickness of cavity structure then can change to make the grid capacitance change, and then can make thin film transistor's channel current change, thereby can realize the signal measurement of pressure, consequently through the connection and the rank scanning processing of a plurality of above-mentioned thin film transistor, form pressure sensor, can realize the realization of pressure distribution test and touch-control function.)
1. A thin film transistor, comprising: the substrate comprises a substrate base plate, a grid electrode and an active layer, wherein the grid electrode and the active layer are arranged on the substrate base plate in a stacked mode, and a cavity structure is arranged between the grid electrode and the active layer; the orthographic projection of the cavity structure on the substrate at least covers the orthographic projection of the active layer on the substrate.
2. The thin film transistor according to claim 1, further comprising a source electrode and a drain electrode electrically connected to the active layer; the source electrode and the drain electrode are adjacent to the active layer, and the source electrode and the drain electrode are located below the active layer.
3. The thin film transistor of claim 2, wherein the active layer is between the substrate base plate and the gate electrode, the thin film transistor further comprising a gate insulating layer between the cavity structure and the gate electrode; the gate insulating layer contacts the source and drain electrodes.
4. The thin film transistor according to claim 2, wherein the active layer is located between the substrate base plate and the gate electrode, the thin film transistor further comprising a gate insulating layer located between the cavity structure and the active layer, and a protective layer located on a side of the gate electrode facing away from the substrate base plate; the protective layer is in contact with the gate insulating layer.
5. The thin film transistor of any of claims 2-4, wherein an orthographic projection of the cavity structure on the substrate base plate further covers an orthographic projection of the source and drain electrodes on the substrate base plate.
6. A pressure sensor comprising a pressure sensing cell, the pressure sensing cell comprising a thin film transistor according to any one of claims 1 to 5.
7. A pressure sensing device comprising the pressure sensor of claim 6.
8. A method of manufacturing a thin film transistor according to any one of claims 1 to 5, comprising:
forming a gate electrode and an active layer which are arranged in a stacked manner on a substrate, and forming a cavity structure between the gate electrode and the active layer; wherein an orthographic projection of the cavity structure on the substrate at least covers an orthographic projection of the active layer on the substrate.
9. The method according to claim 8, wherein forming a gate electrode and an active layer stacked on a substrate, and forming a cavity structure between the gate electrode and the active layer, specifically comprises:
forming a source electrode and a drain electrode on the substrate base plate;
forming an active layer on the source electrode and the drain electrode, wherein the active layer is electrically connected with the source electrode and the drain electrode and is positioned on an adjacent film layer;
forming a sacrificial layer on the active layer; the orthographic projection of the sacrificial layer on the substrate covers the orthographic projection of the active layer and the source electrode and the drain electrode on the substrate;
forming a gate insulating layer on the sacrificial layer; wherein the gate insulating layer is in contact with the source and drain electrodes;
forming a via hole on the gate insulating layer, and etching off the sacrificial layer through the via hole by using an etchant only capable of etching the sacrificial layer to form the cavity structure;
and forming a gate electrode on the gate insulating layer.
10. The method according to claim 8, wherein forming a gate electrode and an active layer stacked on a substrate, and forming a cavity structure between the gate electrode and the active layer, specifically comprises:
forming a source electrode and a drain electrode on the substrate base plate;
forming an active layer on the source electrode and the drain electrode, wherein the active layer is electrically connected with the source electrode and the drain electrode and is positioned on an adjacent film layer;
forming a gate insulating layer on the active layer;
forming a sacrificial layer on the gate insulating layer; the orthographic projection of the sacrificial layer on the substrate covers the orthographic projection of the active layer and the source electrode and the drain electrode on the substrate;
forming a gate on the sacrificial layer;
forming a protective layer on the gate electrode; wherein the protective layer is in contact with the gate insulating layer;
and forming a through hole on the protective layer, and etching off the sacrificial layer through the through hole by using an etchant only capable of etching the sacrificial layer to form the cavity structure.
Technical Field
The invention relates to the technical field of electronics, in particular to a thin film transistor, a manufacturing method thereof, a pressure sensor and a pressure sensing device.
Background
In recent years, the development of sensors has been widely regarded and researched, and both scientific research and enterprises have gradually regarded the importance of research and production of sensors, so that the rapid development in the fields of artificial intelligence, wearable electronics, internet of things and the like is promoted, the requirements of people on sensor devices are higher and higher, and the sensors are also developed towards the directions of high sensitivity, multi-type, flexibility, small size and the like.
The pressure sensor can sense the change of pressure signals, and is applied to the fields of intelligent bionic robots, life health, mobile life, wearable electronics and the like. However, the structural and performance limitations of the conventional pressure sensor make it difficult to meet the device performance requirements of people in related fields. Therefore, the development of new pressure sensing devices meeting high performance requirements is becoming an important direction for the development thereof.
Disclosure of Invention
The embodiment of the invention provides a thin film transistor, a manufacturing method thereof, a pressure sensor and a pressure sensing device, which can realize pressure distribution test and touch function test.
Based on this, an embodiment of the present invention provides a thin film transistor, including: the substrate comprises a substrate base plate, a grid electrode and an active layer, wherein the grid electrode and the active layer are arranged on the substrate base plate in a stacked mode, and a cavity structure is arranged between the grid electrode and the active layer; the orthographic projection of the cavity structure on the substrate at least covers the orthographic projection of the active layer on the substrate.
Optionally, in specific implementation, in the thin film transistor provided in the embodiment of the present invention, a source electrode and a drain electrode electrically connected to the active layer are further included; the source electrode and the drain electrode are adjacent to the active layer, and the source electrode and the drain electrode are located below the active layer.
Optionally, in a specific implementation, in the thin film transistor provided in the embodiment of the present invention, the active layer is located between the substrate and the gate electrode, and the thin film transistor further includes a gate insulating layer located between the cavity structure and the gate electrode; the gate insulating layer contacts the source and drain electrodes.
Optionally, in a specific implementation, in the thin film transistor provided in the embodiment of the present invention, the active layer is located between the substrate and the gate electrode, the thin film transistor further includes a gate insulating layer located between the cavity structure and the active layer, and a protective layer located on a side of the gate electrode opposite to the substrate; the protective layer is in contact with the gate insulating layer.
Optionally, in a specific implementation, in the thin film transistor provided in the embodiment of the present invention, an orthographic projection of the cavity structure on the substrate further covers an orthographic projection of the source and the drain on the substrate.
Correspondingly, the embodiment of the invention also provides a pressure sensor, which comprises a pressure sensing unit, wherein the pressure sensing unit comprises the thin film transistor provided by any one of the embodiments of the invention.
Correspondingly, the embodiment of the invention also provides a pressure sensing device which comprises the pressure sensor provided by the embodiment of the invention.
Correspondingly, an embodiment of the present invention further provides a method for manufacturing a thin film transistor, including:
forming a gate electrode and an active layer which are arranged in a stacked manner on a substrate, and forming a cavity structure between the gate electrode and the active layer; wherein an orthographic projection of the cavity structure on the substrate at least covers an orthographic projection of the active layer on the substrate.
Optionally, in a specific implementation, in the above manufacturing method provided by the embodiment of the present invention, forming a gate electrode and an active layer stacked on a substrate, and forming a cavity structure between the gate electrode and the active layer specifically includes:
forming a source electrode and a drain electrode on the substrate base plate;
forming an active layer on the source electrode and the drain electrode, wherein the active layer is electrically connected with the source electrode and the drain electrode and is positioned on an adjacent film layer;
forming a sacrificial layer on the active layer; the orthographic projection of the sacrificial layer on the substrate covers the orthographic projection of the active layer and the source electrode and the drain electrode on the substrate;
forming a gate insulating layer on the sacrificial layer; wherein the gate insulating layer is in contact with the source and drain electrodes;
forming a via hole on the gate insulating layer, and etching off the sacrificial layer through the via hole by using an etchant only capable of etching the sacrificial layer to form the cavity structure;
and forming a gate electrode on the gate insulating layer.
Optionally, in a specific implementation, in the above manufacturing method provided by the embodiment of the present invention, forming a gate electrode and an active layer stacked on a substrate, and forming a cavity structure between the gate electrode and the active layer specifically includes:
forming a source electrode and a drain electrode on the substrate base plate;
forming an active layer on the source electrode and the drain electrode, wherein the active layer is electrically connected with the source electrode and the drain electrode and is positioned on an adjacent film layer;
forming a gate insulating layer on the active layer;
forming a sacrificial layer on the gate insulating layer; the orthographic projection of the sacrificial layer on the substrate covers the orthographic projection of the active layer and the source electrode and the drain electrode on the substrate;
forming a gate on the sacrificial layer;
forming a protective layer on the gate electrode; wherein the protective layer is in contact with the gate insulating layer;
and forming a through hole on the protective layer, and etching off the sacrificial layer through the through hole by using an etchant only capable of etching the sacrificial layer to form the cavity structure.
The embodiment of the invention has the following beneficial effects:
the thin film transistor, the manufacturing method thereof, the pressure sensor and the pressure sensing device provided by the embodiment of the invention comprise: the substrate base plate is positioned on the grid electrode and the active layer which are arranged on the substrate base plate in a stacked mode, and a cavity structure is arranged between the grid electrode and the active layer; the orthographic projection of the cavity structure on the substrate at least covers the orthographic projection of the active layer on the substrate. Through setting up the cavity structure between grid and active layer, this cavity structure is equivalent to thin film transistor's additional insulating layer, so, when pressing thin film transistor's grid one side, the thickness of cavity structure then can change to make the grid capacitance change, and then can make thin film transistor's channel current change, thereby can realize the signal measurement of pressure, consequently through the connection and the rank scanning processing of a plurality of above-mentioned thin film transistor, form pressure sensor, can realize the realization of pressure distribution test and touch-control function.
Drawings
Fig. 1 is a schematic structural diagram of a thin film transistor according to an embodiment of the present invention;
fig. 2 is a second schematic structural diagram of a thin film transistor according to an embodiment of the present invention;
fig. 3 is a schematic top view of a thin film transistor according to an embodiment of the present invention;
fig. 4 is a flowchart illustrating a method for fabricating a thin film transistor according to an embodiment of the present invention;
FIGS. 5A-5G are schematic structural diagrams of the TFT shown in FIG. 1 after each step is performed;
fig. 6 is a second flowchart of a method for manufacturing a thin film transistor according to an embodiment of the invention;
fig. 7A to 7G are schematic structural diagrams of the thin film transistor shown in fig. 2 after each step is performed.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, a thin film transistor, a method for manufacturing the thin film transistor, a pressure sensor and a pressure sensing device according to embodiments of the present invention will be described in further detail with reference to the accompanying drawings. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The thicknesses and shapes of the respective layers in the drawings are not intended to reflect the true proportions of the thin film transistors, and are merely illustrative of the present invention.
As shown in fig. 1 and 2, a thin film transistor provided in an embodiment of the present invention includes: the device comprises a
In the thin film transistor provided by the embodiment of the invention, the
Further, in practical implementation, in the thin film transistor provided in the embodiment of the present invention, as shown in fig. 1 and fig. 2, the thin film transistor further includes a
Further, in practical implementation, in the thin film transistor provided in the embodiment of the present invention, as shown in fig. 1, the
Further, in the implementation, in order to protect the gate from other process layers, as shown in fig. 1, the thin film transistor provided in the embodiment of the present invention further includes a
Further, in practical implementation, in the thin film transistor provided in the embodiment of the present invention, as shown in fig. 2, the
Further, in specific implementation, in the thin film transistor provided in the embodiment of the present invention, as shown in fig. 1 to fig. 3, fig. 3 is a schematic top view structure diagram of the thin film transistor shown in fig. 1 and fig. 2, in order to enable a channel current of the thin film transistor to change during pressing, so that signal measurement of pressure can be achieved, an orthographic projection of the
Based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a thin film transistor, including:
forming a gate electrode and an active layer which are arranged in a stacked manner on a substrate, and forming a cavity structure between the gate electrode and the active layer; wherein, the orthographic projection of the cavity structure on the substrate at least covers the orthographic projection of the active layer on the substrate.
In the method for manufacturing the thin film transistor, the cavity structure is formed between the gate and the active layer, and the cavity structure is equivalent to an additional insulating layer of the thin film transistor, so that when one side of the gate of the thin film transistor is pressed, the thickness of the cavity structure is changed, the gate capacitance is changed, the channel current of the thin film transistor is changed, and the pressure signal measurement can be realized.
Further, in practical implementation, in the above manufacturing method provided by the embodiment of the present invention, the forming a stacked gate electrode and an active layer on the substrate, and forming a cavity structure between the gate electrode and the active layer, as shown in fig. 4, specifically includes:
s401, forming a source electrode and a drain electrode on a substrate;
specifically, as shown in fig. 5A, a
S402, forming an active layer which is electrically connected with the source electrode and the drain electrode and is positioned on the adjacent film layer on the source electrode and the drain electrode;
specifically, as shown in fig. 5B, the
S403, forming a sacrificial layer on the active layer; orthographic projection of the sacrificial layer substrate on the substrate covers the active layer and orthographic projection of the source electrode and the drain electrode on the substrate;
specifically, as shown in fig. 5C, a
Specifically, the material of the
S404, forming a gate insulating layer on the sacrificial layer; wherein the gate insulating layer is in contact with the source and drain electrodes;
specifically, as shown in fig. 5D, a
S405, forming a via hole on the gate insulating layer, and etching off the sacrificial layer through the via hole by using an etchant only capable of etching the sacrificial layer to form a cavity structure;
specifically, as shown in fig. 5E, a via
S406, forming a grid electrode on the grid insulating layer;
specifically, as shown in fig. 5G, the
Further, as shown in fig. 1, a
Further, in practical implementation, in the above manufacturing method provided by the embodiment of the present invention, the forming a stacked gate electrode and an active layer on the substrate, and forming a cavity structure between the gate electrode and the active layer, as shown in fig. 6, specifically includes:
s601, forming a source electrode and a drain electrode on a substrate;
specifically, as shown in fig. 7A, a
S602, forming an active layer which is electrically connected with the source electrode and the drain electrode and is positioned on the adjacent film layer on the source electrode and the drain electrode;
specifically, as shown in fig. 7B, the
S603, forming a gate insulating layer on the active layer;
specifically, as shown in fig. 7C, a
S604, forming a sacrificial layer on the gate insulating layer; orthographic projection of the sacrificial layer substrate on the substrate covers the active layer and orthographic projection of the source electrode and the drain electrode on the substrate;
specifically, as shown in fig. 7D, a
S605, forming a grid electrode on the sacrificial layer;
specifically, as shown in fig. 7E, the
S606, forming a protective layer on the grid; wherein the protective layer is in contact with the gate insulating layer;
specifically, as shown in fig. 7F, a
S607, forming a via hole on the protective layer, and corroding the sacrificial layer through the via hole by adopting a corrosive capable of only corroding the sacrificial layer to form a cavity structure;
specifically, as shown in fig. 7G, a via
It should be noted that, in the manufacturing method of the thin film transistor provided in the embodiment of the present invention, for a specific film pattern in each film, a patterning process may be used, where the patterning process may refer to a process including a photolithography process, or may include a photolithography process and an etching step, and may also include other processes for forming a predetermined pattern, such as printing, inkjet printing, and the like; the photolithography process is a process of forming a pattern by using a photoresist, a mask plate, an exposure machine, and the like, including processes of film formation, exposure, development, and the like. In particular implementations, the corresponding patterning process may be selected based on the structure formed in the present invention.
Based on the same inventive concept, the embodiment of the invention further provides a pressure sensor, which comprises a pressure sensing unit, wherein the pressure sensing unit comprises any one of the thin film transistors provided by the embodiment of the invention. The principle of solving the problem of the pressure sensor is similar to that of the thin film transistor, so the implementation of the pressure sensor can be referred to the implementation of the thin film transistor, and repeated details are not repeated herein.
In the implementation, the pressure sensor generally includes a plurality of pressure sensing units, but if necessary, only one pressure sensing unit may be provided, and the pressure sensing may be realized by a plurality of pressure sensing units.
In this embodiment, the plurality of pressure sensing units in the pressure sensor are preferably distributed in a matrix, but not limited thereto. In the present invention, the specific form of the pressure sensor is not limited, and may be a pulse sensor, an ultra-micro force sensor, an acoustic sensor, or the like.
Based on the same inventive concept, the embodiment of the invention also provides a pressure sensing device, which comprises the pressure sensor provided by the embodiment of the invention. The principle of the pressure sensing device to solve the problem is similar to the aforementioned thin film transistor, so the implementation of the pressure sensing device can refer to the implementation of the aforementioned thin film transistor, and the repeated points are not described herein again.
It should be noted that, in the embodiment of the present invention, the pressure sensing apparatus may be at least applied to the field of wearable devices, for example, a pulse sensor; the method can also be applied to the fields of fingerprint identification, touch control and the like, such as mobile phones, computers and the like; the present invention is not particularly limited in this regard.
The thin film transistor, the manufacturing method thereof, the pressure sensor and the pressure sensing device provided by the embodiment of the invention comprise: the substrate base plate is positioned on the grid electrode and the active layer which are arranged on the substrate base plate in a stacked mode, and a cavity structure is arranged between the grid electrode and the active layer; the orthographic projection of the cavity structure on the substrate at least covers the orthographic projection of the active layer on the substrate. Through setting up the cavity structure between grid and active layer, this cavity structure is equivalent to thin film transistor's additional insulating layer, so, when pressing thin film transistor's grid one side, the thickness of cavity structure then can change to make the grid capacitance change, and then can make thin film transistor's channel current change, thereby can realize the signal measurement of pressure, consequently through the connection and the rank scanning processing of a plurality of above-mentioned thin film transistor, form pressure sensor, can realize the realization of pressure distribution test and touch-control function.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
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