CN110504323B - Flexible thin film transistor and preparation method thereof - Google Patents
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- CN110504323B CN110504323B CN201910805592.7A CN201910805592A CN110504323B CN 110504323 B CN110504323 B CN 110504323B CN 201910805592 A CN201910805592 A CN 201910805592A CN 110504323 B CN110504323 B CN 110504323B
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- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/24—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/49—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET
- H01L29/51—Insulating materials associated therewith
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- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66969—Multistep manufacturing processes of devices having semiconductor bodies not comprising group 14 or group 13/15 materials
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- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/78—Field effect transistors with field effect produced by an insulated gate
- H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
- H01L29/78603—Thin film transistors, i.e. transistors with a channel being at least partly a thin film characterised by the insulating substrate or support
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- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/78—Field effect transistors with field effect produced by an insulated gate
- H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
- H01L29/78696—Thin film transistors, i.e. transistors with a channel being at least partly a thin film characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel
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Abstract
The invention belongs to the technical field of semiconductor devices, and particularly relates to a flexible thin film transistor and a preparation method thereof. The device comprises a bottom gate electrode (4), a gate dielectric layer (1), a source electrode (2), a drain electrode (3) and a transistor channel layer (5) from bottom to top. In the flexible thin film transistor, a polyimide film is directly used as a gate dielectric layer; after the surface treatment is carried out on the polyimide film, catalytic seed layers are respectively sprayed and printed on two sides of the polyimide film, then the polyimide film is placed in chemical copper deposition liquid to chemically grow metal copper, and a copper source electrode (2), a copper drain electrode (3) and a copper grid electrode (4) are respectively formed on two sides of the polyimide substrate; the active layer is formed using inkjet printing. The method for forming the flexible thin film transistor is simple, efficient and low in cost; the prepared flexible thin film transistor has the advantages of simple structure, excellent electrical property and good bending resistance.
Description
Technical Field
The invention belongs to the technical field of semiconductor devices, and particularly relates to a flexible thin film transistor and a preparation method thereof.
Background
In recent years, transition metal chalcogenides having a graphene-like layered structure have attracted much attention. Most transition metal chalcogenides have a natural band gap of 1-2 eV, and the materials have excellent physical properties, so that the transition metal chalcogenides have great application potential in the aspect of logic digital integrated circuits. In particular, the direct bandgap properties of single layer transition metal chalcogenides make them important for applications in the fields of optics, opto-electronic devices and sensors.
In the traditional process for preparing the transistor, a device channel is prepared by adopting a photoetching technology, and complicated processes such as photoetching, developing, etching and the like are required. The ink jet printing technology shows advantages gradually in the graphical preparation of an electronic material functional layer, a mask plate and photoresist are not needed, the printing process and the printed patterns can be regulated and controlled at will only by adopting a digital printing technology, the ink jet printing technology has the advantages of simplicity, rapidness and high process integration level, the material loss can be controlled to the greatest extent due to the program control accuracy, and the surface state of a substrate can be protected to the greatest extent due to the characteristic that the ink jet printing technology does not need to be in contact with and the ink jet printing distance can be adjusted.
At present, the two-dimensional transition metal chalcogenide material is applied to the thin film transistor, and has the following problems: (1) the single-layer or few-layer two-dimensional transition metal chalcogenide material is mostly prepared by adopting a chemical vapor deposition method and then is transferred to SiO2On the Si substrate, the operation difficulty is high, the process flexibility is poor, the process period is long, and the device yield is low; (2) the thin film transistor based on the few-layer two-dimensional transition metal chalcogenide material has poor performance; (3) the source electrode and the drain electrode are prepared by adopting the traditional micromachining process, so that the problems of high production cost and complex process exist; (4) in the research of preparing the flexible thin film transistor by adopting the printing technology, the source electrode, the drain electrode and the grid electrode are prepared by printing silver conductive ink, and a printed organic polymer insulating material is used as a grid electrode insulating layer, so that the preparation cost is high, the compatibility among functional layers is poor, and the device performance is poor due to the limitation of the flexible substrate on high-temperature annealing.
Disclosure of Invention
Aiming at the problems of the two-dimensional transition metal chalcogenide thin film transistor realized by the prior art, the invention provides a flexible thin film transistor and a preparation method thereof, and the purpose is as follows: the preparation process of the flexible thin film transistor is simplified, the preparation difficulty is reduced, the preparation cost is greatly reduced, the device structure is simple, batch preparation can be realized, and the performance is excellent.
The technical scheme adopted by the invention is as follows:
a flexible thin film transistor sequentially comprises a bottom gate electrode, an insulated gate dielectric layer, a source-drain electrode array layer and an active layer from bottom to top, wherein the insulated gate dielectric layer is simultaneously used as a substrate of the flexible thin film transistor, and the source-drain electrode array layer is composed of an array consisting of a source electrode and a drain electrode.
In the technical scheme, the substrate material is used as an insulated gate dielectric layer, and in addition, the thin film transistor belongs to a bottom gate bottom contact structure, so that the preparation method of the thin film transistor is simple and easy.
Preferably, the insulating gate dielectric layer is made of flexible polyimide, and the thickness of the polyimide film is less than 100 μm.
Preferably, the bottom gate electrode, the source electrode and the drain electrode are made of metal Cu, and the active layer is made of one of two-dimensional molybdenum disulfide, tungsten disulfide and molybdenum diselenide.
Preferably, the length of a channel between the source electrode and the drain electrode is less than 100 μm, and the active layer covers the channel formed by the source electrode and the drain electrode and is in contact with the source electrode and the drain electrode.
By adopting the preferable scheme, the flexible thin film transistor can be ensured to have excellent performance.
The invention also provides a preparation method of the flexible thin film transistor, which comprises the following steps:
[1] performing surface treatment on the polyimide material, cleaning and drying the polyimide material, taking the polyimide material as a substrate and taking the substrate as an insulated gate dielectric layer of the thin film transistor;
[2]double-sided spray printing of Pd-containing on polyimide substrate by using ink-jet printer2+、Ag+Or Cu2+One surface of the ink is subjected to whole-surface jet printing, and the other surface is subjected to patterned jet printing;
[3]spraying Pd-containing ink2+、Ag+Or Cu2+The polyimide substrate of the ink is dipped in the Cu-containing solution2+Forming a copper source electrode, a drain electrode and a gate electrode in the chemical copper deposition solution, wherein the source electrode and the drain electrode form a patterned source-drain electrode array;
[4] and (4) utilizing an ink-jet printer to spray and print ink containing the active layer material on the source and drain electrode array obtained in the step (3), and drying to obtain the flexible thin film transistor.
After the preferred scheme is adopted, the source electrode and the drain electrode are manufactured without adopting the traditional photoetching process in the device manufacturing process; complex processes such as interface modification treatment and doping of the active layer are not required; meanwhile, the source electrode, the drain electrode and the gate electrode can be formed in the chemical copper deposition solution at one time, and a copper layer with high crystallization quality is formed through growth, so that high conductivity can be obtained without high-temperature annealing. In addition, the few layers of active layer materials prepared by liquid phase stripping can be directly used as functional ink components for ink-jet printing, and the steps greatly simplify the preparation process of the flexible thin film transistor.
And forming a catalytic pattern by spray printing and forming a source and drain electrode array by chemical copper deposition, reserving a channel between each pair of source and drain electrodes, and forming the whole surface of the grid electrode on the other surface of the polyimide substrate. The subsequent active layer is conveniently and quickly deposited on the source-drain electrode array and in the channel through ink jet printing, so that the complete alignment of the grid and the channel is accurately ensured, and the grid control capability of the bottom grid is improved.
The preparation of the flexible thin film transistor is realized by adopting an ink jet printing mode, and the preparation method has the remarkable characteristics of accurate control, convenience in forming, rapidness and batch preparation.
Preferably, the polyimide substrate in the step [1] is subjected to surface treatment by using alkali liquor, and polyimide molecules on the surface of the polyimide substrate after the surface treatment are hydrolyzed to form carboxylate radicals.
Preferably, said step [2]]Pd-containing ink for medium ink-jet printing2+、Ag+Or Cu2+The ink is characterized in that metal ions in the ink form chemical bonding with carboxylate radicals in the polyimide substrate, and a metal simple substance formed by reducing the metal ions is used for catalyzing subsequent chemical copper deposition.
Preferably, the pattern formed in step [2] is jet printed, and the distance between adjacent lines is less than 100 μm.
Preferably, in step [3]The conductivity of the source electrode, the drain electrode and the gate electrode is more than 2 x 10 by controlling the deposition growth conditions5S/cm。
Preferably, the preparation of the ink containing the active layer material in the step [4] adopts a liquid-phase ultrasonic stripping technology, obtains the active layer material with a few-layer laminated structure by controlling liquid-phase ultrasonic conditions, and prepares the active layer material into the ink.
In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:
1) the process is simplified: in the preparation process of the device, the source electrode and the drain electrode are manufactured without adopting the traditional photoetching process, and the source electrode, the drain electrode and the gate electrode can be formed on the substrate through one-time chemical deposition growth without high-temperature treatment; complex processes such as interface modification treatment and doping of the active layer to improve interface compatibility are not required; in addition, the few layers of active layer materials prepared by liquid phase stripping can be directly used as functional ink components for ink-jet printing, and the steps greatly simplify the preparation process of the flexible thin film transistor.
2) The cost is greatly reduced: the invention completely departs from the traditional transistor manufacturing process, the source electrode, the drain electrode and the gate electrode do not need to be formed by photoetching, silver conductive ink with high cost does not need to be sprayed and printed, and the copper electrode can be formed at one time by adopting catalytic chemical deposition growth; the insulated gate dielectric layer is formed without spraying and printing a high-molecular insulating material, and the polyimide substrate is used as the insulated gate dielectric layer, so that the manufacturing cost is greatly reduced.
3) The device has excellent electrical performance: carboxylic acid heel groups formed on the surface of the polyimide substrate after surface treatment form chemical bonding with subsequent metal ions, which is favorable for firmly attaching a chemically deposited metal copper electrode on the polyimide substrate; the work function of copper metal is 4.65eV, and the copper metal is very close to the electron affinity of few layers of molybdenum disulfide, namely 4.80eV, so that the contact potential barrier between an electrode and an active layer is small, and the energy level matching performance is good; the ink of the active layer material can form continuous and uniform channels on the polyimide substrate through characteristic adjustment (viscosity, surface tension, adhesiveness and the like); the adoption of the digital ink jet printing technology can conveniently form a conductive channel aligned with the back gate, and the gate control capability of the back gate is strong. The technical measures and the simplification of the device structure effectively reduce the adverse effect of the interface effect on the performance of the device, and the electrical performance of the device is excellent.
4) The active layer material used in the invention is a two-dimensional layered structure material, the selected gate dielectric material is used as a substrate and has good flexibility, and the gate electrode, the source electrode and the drain electrode are firmly attached to the polyimide substrate through chemical deposition, so that the thin film transistor can support bending at a larger angle and has almost no influence on the performance of a device.
Drawings
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a flexible thin film transistor structure of the present invention;
fig. 2 is a schematic view of each step in the manufacturing method of the flexible thin film transistor of the present invention;
FIG. 3 is a schematic top view of a source drain electrode array and an active layer in a flexible thin film transistor according to the present invention;
fig. 4 is a performance test chart of the flexible thin film transistor manufactured in the example of the present invention.
Wherein: 1-an insulated gate dielectric layer, 2-a source electrode, 3-a drain electrode, 4-a bottom gate electrode and 5-an active layer.
Detailed Description
All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.
A flexible thin film transistor comprises a bottom gate electrode 4, an insulated gate dielectric layer 1, a source and drain electrode array layer and an active layer 5 from bottom to top in sequence, wherein the insulated gate dielectric layer is simultaneously used as a substrate of the flexible thin film transistor, and the source and drain electrode array layer is composed of an array consisting of a source electrode 2 and a drain electrode 3.
Preferably, the insulating gate dielectric layer 1 is made of polyimide which is a flexible material, and the thickness of the polyimide film is less than 100 μm.
Preferably, the material of the bottom gate electrode 4, the source electrode 2 and the drain electrode 3 is Cu, and the material of the active layer 5 includes one of two-dimensional molybdenum disulfide, tungsten disulfide or molybdenum diselenide.
Preferably, the length of the channel between the source electrode 2 and the drain electrode 3 is less than 100 μm, and the active layer 5 covers the channel formed by the source electrode 2 and the drain electrode 3 and is in contact with the source electrode and the drain electrode.
The invention also provides a preparation method of the flexible thin film transistor, which comprises the following steps:
[1] performing surface treatment on the polyimide material, cleaning and drying the polyimide material, taking the polyimide material as a substrate and taking the substrate as an insulated gate dielectric layer of the thin film transistor;
[2]double-sided spray printing of Pd-containing on polyimide substrate by using ink-jet printer2+、Ag+Or Cu2+One surface of the ink is subjected to whole-surface jet printing, and the other surface is subjected to patterned jet printing;
[3]spraying Pd-containing ink2+、Ag+Or Cu2+The polyimide substrate of the ink is dipped in the Cu-containing solution2+Forming a copper source electrode, a drain electrode and a gate electrode in the chemical copper deposition solution, wherein the source electrode and the drain electrode form a patterned source-drain electrode array;
[4] and (4) utilizing an ink-jet printer to spray and print ink containing the active layer material on the source and drain electrode array obtained in the step (3), and drying to obtain the flexible thin film transistor.
As a preferable scheme, in the step [1], the polyimide substrate is subjected to surface treatment by using alkali liquor, and polyimide molecules on the surface of the polyimide substrate after the surface treatment are hydrolyzed to form carboxylate groups. The alkali treatment process includes washing substrate, soaking in 4-7M NaOH solution at 30-50 deg.c for 1-3 hr.
As a preferable mode, said step [2]]Pd-containing ink for medium ink-jet printing2+、Ag+Or Cu2+The ink is characterized in that metal ions in the ink form chemical bonding with carboxylate radicals in the polyimide substrate, and a metal simple substance formed by reducing the metal ions is used for catalyzing subsequent chemical copper deposition.
Preferably, the pattern formed by the jet printing in the step [2] has a pitch of adjacent lines of less than 100 μm.
As a preferred embodiment, in step (ii), the step (ii) is performed[3]The conductivity of the source electrode, the drain electrode and the gate electrode is more than 2 x 10 by controlling the deposition growth conditions5S/cm。
As a preferable scheme, the preparation of the ink containing the active layer material in the step [4] adopts a liquid-phase ultrasonic stripping technology, obtains the active layer material with a few-layer laminated structure by controlling liquid-phase ultrasonic conditions, and prepares the active layer material into the ink.
Examples
Fig. 1 is a longitudinal cross-sectional view of the thin film transistor of this embodiment, which includes an insulated gate dielectric layer 1 with a polyimide substrate as a substrate; after the surface of the insulated gate dielectric layer 1 is treated by alkali liquor, a patterned catalytic seed layer is printed on the insulated gate dielectric layer by ink jet printing, and the patterned catalytic seed layer is grown by chemical deposition to be used as a source electrode 2 and a drain electrode 3 of the thin film transistor; an active layer 5 which takes two-dimensional material molybdenum disulfide as channel material is arranged on the source electrode and the drain electrode; and the bottom gate electrode is positioned on the back of the gate dielectric layer 1 and is obtained by chemical deposition together with the source electrode and the drain electrode.
Fig. 2 shows a method for manufacturing a flexible thin film transistor in this embodiment, which includes the following steps:
1) performing surface treatment on the polyimide substrate: a polyimide film (TS-
Dupont) were cut into 50mm × 50mm squares and washed with deionized water, ethanol, in that order, until use. The substrate was immersed in a prepared 4M NaOH solution for 1 hour at 30 ℃. In the process, under the action of strong alkali, an imide ring is broken, and the surface of the substrate is hydrolyzed to form polyamic acid salt.
2) Spraying and printing a catalytic seed layer on the substrate: and repeatedly washing the substrate subjected to surface treatment by using deionized water and drying. Printing Ag on one side of polyimide substrate by using ink-jet printer+Forming a catalytic seed layer with ink, printing with an area of 50mm × 50mm (i.e. the printing area completely covers the whole substrate), drying at 50 deg.C, and printing Ag on the other side of the polyimide substrate by ink jet printer+Ink formationA patterned catalytic seed layer, wherein the line pitch of the preformed source and drain electrodes is less than 100 μm. Ag+Spray-printing on the surface of polyimide substrate, and reacting with reactive group-COO on the surface of substrate-And (4) combining.
3) Chemical deposition growth of source, drain and gate electrodes: and (2) placing the polyimide substrate with the surface covered with the catalytic seed layer in chemical copper plating solution, growing copper metal on two sides of the polyimide substrate through chemical deposition, and forming a source electrode, a drain electrode and a gate electrode at one time, wherein the electrode distance is less than 100 microns (as shown in figure 3) after the source electrode and the drain electrode are formed on the catalytic seed layer which is printed in advance. Controlling the chemical deposition conditions to make the conductivity of the copper layer greater than 2 x 105S/cm. A typical electroless copper plating bath formulation is shown in Table 1, with a deposition temperature of 40 ℃ and a deposition time of 20 minutes.
TABLE 1 chemical copper deposition bath formulation
4) Inkjet printing of active layers and transistor device formation: a liquid phase ultrasonic stripping method is adopted, and powdery molybdenum disulfide is placed in a volume ratio of 1: 1, adding polyvinylpyrrolidone serving as a dispersing agent and a stabilizing agent into the absolute ethyl alcohol-deionized water, and performing liquid phase ultrasound at 25 ℃ for 24 hours to obtain a suspension containing few layers of molybdenum disulfide nanosheets. And preparing the molybdenum disulfide suspension into ink, and carrying out ink-jet printing on the source and drain electrode array to form an active layer. And after the device is prepared, putting the device into a 50 ℃ oven for drying.
The thin film transistor prepared in this example has the electrical performance test result shown in FIG. 4, the Subthreshold Swing (SS) is as low as 65mV/dec (approaching the theoretical value of 60mV/dec at room temperature), and the on-off current ratio (I)on/Ioff) Up to 104(ii) a When the source-drain voltage VDS3.0V, gate voltage VGSWhen it is 3.0V, on stateThe current reaches 20 muA; when the source-drain voltage is increased from 2.0V to 3.0V, the threshold roll is reduced to 0.2V. In addition, the two-dimensional layered material molybdenum disulfide has good flexibility, and the prepared flexible thin film transistor can still keep excellent performance after being bent at a large angle. The performance of the thin film transistor is superior to that of the flexible thin film transistor prepared by the prior art.
The above-mentioned embodiments only express the specific embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, without departing from the technical idea of the present application, several changes and modifications can be made, which are all within the protection scope of the present application.
Claims (10)
1. A flexible thin film transistor, characterized by: the flexible thin film transistor comprises a bottom gate electrode (4), an insulated gate dielectric layer (1), a source and drain electrode array layer and an active layer (5) from bottom to top in sequence, wherein the insulated gate dielectric layer is simultaneously used as a substrate of the flexible thin film transistor, and the source and drain electrode array layer is formed by an array consisting of a source electrode (2) and a drain electrode (3).
2. A flexible thin film transistor according to claim 1, wherein: the insulated gate dielectric layer (1) is made of flexible polyimide, and the thickness of the polyimide film is smaller than 100 microns.
3. A flexible thin film transistor according to claim 1, wherein: the bottom gate electrode (4), the source electrode (2) and the drain electrode (3) are made of metal Cu, and the active layer (5) is made of one of two-dimensional molybdenum disulfide, tungsten disulfide or molybdenum diselenide.
4. A flexible thin film transistor according to claim 1, wherein: the length of a channel between the source electrode (2) and the drain electrode (3) is less than 100 mu m, and the active layer (5) covers the channel formed by the source electrode (2) and the drain electrode (3) and is in contact with the source electrode and the drain electrode.
5. A method for preparing a flexible thin film transistor according to claim 1, comprising the steps of:
[1] performing surface treatment on the polyimide film, cleaning and drying the polyimide film, taking the polyimide film as a substrate and taking the substrate as an insulated gate dielectric layer of a thin film transistor;
[2]double-sided spray printing of Pd-containing on polyimide substrate by using ink-jet printer2+、Ag+Or Cu2+One surface of the ink is subjected to whole-surface jet printing, and the other surface is subjected to patterned jet printing;
[3]spraying Pd-containing ink2+、Ag+Or Cu2+The polyimide substrate of the ink is dipped in the Cu-containing solution2+Forming a copper source electrode, a drain electrode and a gate electrode in the chemical copper deposition solution, wherein the source electrode and the drain electrode form a patterned source-drain electrode array;
[4] and (4) utilizing an ink-jet printer to spray and print ink containing the active layer material on the source and drain electrode array obtained in the step (3), and drying to obtain the flexible thin film transistor.
6. The method of manufacturing a flexible thin film transistor according to claim 5, wherein: and (2) performing surface treatment on the polyimide substrate in the step (1) by adopting alkali liquor, and hydrolyzing polyimide molecules on the surface of the polyimide substrate after the surface treatment to form carboxylate radicals.
7. The method of manufacturing a flexible thin film transistor according to claim 5, wherein: said step [2]Pd-containing ink for medium ink-jet printing2+、Ag+Or Cu2+The ink is characterized in that metal ions in the ink form chemical bonding with carboxylate radicals in the polyimide substrate, and a metal simple substance formed by reducing the metal ions is used for catalyzing subsequent chemical copper deposition.
8. The method of manufacturing a flexible thin film transistor according to claim 5, wherein: and (3) spraying and printing the formed pattern in the step (2), wherein the distance between adjacent lines is less than 100 mu m.
9. The method of manufacturing a flexible thin film transistor according to claim 5, wherein: in step [3]The conductivity of the source electrode, the drain electrode and the gate electrode is more than 2 x 10 by controlling the deposition growth conditions5S/cm。
10. The method of manufacturing a flexible thin film transistor according to claim 5, wherein: and (4) preparing the ink containing the active layer material in the step (4) by adopting a liquid phase ultrasonic stripping technology, controlling the liquid phase ultrasonic condition to obtain the active layer material with a few-layer laminated structure, and preparing the active layer material into the ink.
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