Metal oxide semiconductor thin film and thin film transistor

Abstract

The invention discloses a metal oxide semiconductor thin film and a thin film transistor. The semiconductor thin film comprises a laminated structure formed by at least one layer of high-mobility metal oxide semiconductor thin film and at least one layer of photon-generated carrier quenching metal oxide semiconductor thin film; the photon-generated carrier quenching metal oxide semiconductor thin film is used for quenching photon-generated carriers; the carrier mobility of the high-mobility metal oxide semiconductor film is greater than that of the photon-generated carrier quenching metal oxide semiconductor film; ratio of difference value of carrier concentration of photon-generated carrier quenching metal oxide semiconductor film under illumination condition and dark state condition to carrier concentration under illumination condition is smaller than difference value of carrier concentration of high-mobility metal oxide semiconductor film under illumination condition and dark state condition and carrier concentration under illumination condition and a ratio. According to the scheme, the carrier mobility and the light stability of the metal oxide semiconductor film are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a metal oxide semiconductor film and a thin film transistor. Background Art

[0002] As a key component of liquid crystal and organic displays, thin film transistors play a very important role in the working performance of display devices. Common thin film transistors include amorphous silicon thin film transistors, polycrystalline silicon thin film transistors, organic thin film transistors and metal oxide thin film transistors. At present, metal oxide thin film transistors have attracted widespread attention due to their easy large-area, high mobility, good stability and low cost, and have been widely used in medium and large-size displays. The metal oxide currently used for mass production under the premise of ensuring device stability is indium gallium zinc oxide (IGZO (In:Ga:Zn=1:1:1)). The mobility of this material is relatively low, only 10cm 2 / Vs. However, when people try to improve the mobility of oxide films by changing the components, the stability of the device, especially the light stability, cannot meet the product requirements. Therefore, how to break the contradictory relationship between high mobility and high light stability is the focus of current research on metal oxide semiconductor materials and preparation processes.

[0003] At present, the most widely used film-forming method for oxide film preparation is physical vapor deposition (PVD). However, the density of films prepared by PVD is relatively low and there are many defects. If a higher mobility is required, more In / Sn ion content is required, which has a negative impact on stability, especially photostability. On the other hand, considering that the mobility of oxide semiconductor films is determined by the overlap of ns electron orbits of In / Sn / Ga. Therefore, increasing the density of metal oxide films and reducing the spacing between metal ions can effectively improve the mobility of thin film materials. Therefore, people have set their sights on the atomic layer deposition (ALD) film preparation method for thin film preparation. ALD is a gas phase thin film growth method that uses the principle of saturated adsorption of precursors or reactants on the substrate surface, and then reacting layer by layer to grow a single atomic layer. This growth method determines that the preparation method can obtain highly dense and highly conformal oxide films. At the same time, the thickness of the film can also be precisely controlled. The metal oxide semiconductor films currently grown using this method are made into thin film transistor devices (TFTs), and the mobility can be between 30 and 120 cm 2 / Vs. However, the stability of the TFT device using ALD to prepare the active layer, especially the photostability, is not improved. Rare earth ions are introduced into the metal oxide semiconductor film as light stabilizers. It mainly utilizes the valence change ability of rare earth ions and the appropriate energy level matching to achieve rapid recombination of photogenerated carriers, thereby reducing the impact of light on the performance of TFT devices. However, since the ALD film growth depends on precursor materials, the types of oxide semiconductor materials that can be produced are limited, especially the rare earth organic metal source is not yet mature, and the photostability effect of rare earth ions cannot be utilized. Therefore, it is difficult to improve the stability of active layer TFT devices under light when using ALD to prepare them. In summary, it is very difficult to achieve high carrier mobility and high photostability in a metal oxide semiconductor film layer in the prior art. Summary of the invention

[0004] The invention provides a metal oxide semiconductor film and a thin film transistor to improve the carrier mobility and light stability of the metal oxide semiconductor film.

[0005] According to a first aspect of the present invention, there is provided a metal oxide semiconductor thin film, comprising:

[0006] At least one high-mobility metal oxide semiconductor film;

[0007] At least one layer of photo-generated carrier quenching metal oxide semiconductor film, wherein the photo-generated carrier quenching metal oxide semiconductor film and the high-mobility metal oxide semiconductor film form a stacked structure; the photo-generated carrier quenching metal oxide semiconductor film is used to quench photo-generated carriers;

[0008] The carrier mobility of the high-mobility metal oxide semiconductor film is greater than the carrier mobility of the photogenerated carrier quenching metal oxide semiconductor film;

[0009] The ratio of the difference between the carrier concentration of the photogenerated carrier quenching metal oxide semiconductor film under illumination and under dark conditions to the carrier concentration under illumination is less than the ratio of the difference between the carrier concentration of the high-mobility metal oxide semiconductor film under illumination and under dark conditions to the carrier concentration under illumination.

[0010] According to a second aspect of the present invention, there is provided a thin film transistor comprising any metal oxide semiconductor thin film as described in the first aspect of the present invention.

[0011] The metal oxide semiconductor film provided by the embodiment of the present invention includes a stacked structure consisting of at least one layer of photogenerated carrier quenching metal oxide semiconductor film and at least one layer of high-mobility metal oxide semiconductor film. The photogenerated carrier quenching metal oxide semiconductor film and the high-mobility metal oxide semiconductor film can select their own suitable processes to achieve the high carrier mobility characteristic of the high-mobility metal oxide semiconductor film, as well as the high photostability characteristic of the photogenerated carrier quenching metal oxide semiconductor film, thereby reducing the difficulty of preparing the metal oxide semiconductor film.

[0012] Since the carrier mobility of the high-mobility metal oxide semiconductor film is greater than the carrier mobility of the photogenerated carrier quenching metal oxide semiconductor film, the provision of the high-mobility metal oxide semiconductor film enables the metal oxide semiconductor film to have high carrier mobility.

[0013] The photogenerated carrier quenching metal oxide semiconductor film is used to quench the photogenerated carriers diffused from the high-mobility metal oxide semiconductor film, and the ratio of the difference in carrier concentration between the photogenerated carrier quenching metal oxide semiconductor film under illumination and under dark conditions to the carrier concentration under illumination is less than the ratio of the difference in carrier concentration between the high-mobility metal oxide semiconductor film under illumination and under dark conditions to the carrier concentration under illumination. The setting of the photogenerated carrier quenching metal oxide semiconductor film enables the metal oxide semiconductor film to have high photostability.

[0014] Therefore, the metal oxide semiconductor film provided in the embodiment of the present invention has a stacked structure composed of at least one layer of photogenerated carrier quenching metal oxide semiconductor film and at least one layer of high-mobility metal oxide semiconductor film, so that the metal oxide semiconductor film has both high carrier mobility and high photostability.

[0015] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 is a schematic structural diagram of a thin film transistor provided by an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of the Fermi level of a high-mobility metal oxide semiconductor film and a photogenerated carrier quenching metal oxide semiconductor film;

[0019] Figure 3 yes Figure 1 Schematic diagram of transfer characteristic curves of thin film transistors at 9 different positions;

[0020] Figure 4 yes Figure 1 Schematic diagram of transfer characteristic curves of thin film transistors in light and dark states;

[0021] Figure 5 is a schematic structural diagram of another thin film transistor provided by an embodiment of the present invention;

[0022] Figure 6 is a schematic structural diagram of another thin film transistor provided by an embodiment of the present invention;

[0023] Figure 7 yes Figure 6 A schematic diagram of a transfer characteristic curve of a thin film transistor in light and dark states;

[0024] Figure 8 yes Figure 6 Another transfer characteristic curve diagram of the thin film transistor in the light and dark states;

[0025] Fig. 9 is a schematic structural diagram of another thin film transistor provided by an embodiment of the present invention;

[0026] Fig.10 is a schematic structural diagram of another thin film transistor provided by an embodiment of the present invention;

[0027] Fig.11 is a flow chart of a method for preparing a thin film transistor provided by an embodiment of the present invention;

[0028] Figure 12-Figure 15 yes Fig.11 The structural schematic diagram corresponding to each step in the figure;

[0029] Fig.16 is a flow chart of a method for preparing a thin film transistor provided by an embodiment of the present invention;

[0030] Figure 17-Figure 21 yes Fig.16 The structural schematic diagram corresponding to each step in the figure;

[0031] Fig. 22 is a flow chart of a method for preparing a thin film transistor provided by an embodiment of the present invention;

[0032] Figure 23-Figure 27 yes Fig. 22 The structural schematic diagram corresponding to each step in the figure;

[0033] Fig.28 It is a schematic diagram of the light response characteristics of a thin film transistor whose active layer material is a single layer of high-mobility oxide thin film provided by an embodiment of the present invention;

[0034] Fig.29 The present invention provides a schematic diagram of the light response characteristics of a thin film transistor in which the active layer material is a single-layer photo-generated carrier quenching metal oxide semiconductor film as the active layer. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or devices is not necessarily limited to those steps or devices that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0037] In view of the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0038] like Figure 1 As shown, Figure 11 is a schematic diagram of the structure of a thin film transistor provided by an embodiment of the present invention, wherein the thin film transistor includes a metal oxide semiconductor film 100, wherein the metal oxide semiconductor film 100 includes: at least one high-mobility metal oxide semiconductor film 101; at least one photo-generated carrier quenching metal oxide semiconductor film 102, wherein the photo-generated carrier quenching metal oxide semiconductor film 102 and the high-mobility metal oxide semiconductor film 101 form a stacked structure; the photo-generated carrier quenching metal oxide semiconductor film 102 is used to quench photo-generated carriers; the carrier mobility of the high-mobility metal oxide semiconductor film 101 is greater than the carrier mobility of the photo-generated carrier quenching metal oxide semiconductor film 102; the ratio of the difference between the carrier concentration of the photo-generated carrier quenching metal oxide semiconductor film 102 under illumination and under dark conditions to the carrier concentration under illumination is less than the ratio of the difference between the carrier concentration of the high-mobility metal oxide semiconductor film 101 under illumination and under dark conditions to the carrier concentration under illumination.

[0039] Among them, the difference A0 between the carrier concentration under illumination and the carrier concentration under dark state and the carrier concentration under illumination satisfies the following relationship:

[0040] A0=((n photo -n dark ) / n photo )

[0041] Among them, n photo is the carrier mobility under illumination and the carrier concentration, n dark is the carrier concentration in the dark state.

[0042] The metal oxide semiconductor film 100 provided in the embodiment of the present invention includes a stacked structure consisting of at least one layer of photogenerated carrier quenching metal oxide semiconductor film 102 and at least one layer of high-mobility metal oxide semiconductor film 101. The photogenerated carrier quenching metal oxide semiconductor film 102 and the high-mobility metal oxide semiconductor film 101 can select their own suitable processes to achieve the high carrier mobility characteristic of the high-mobility metal oxide semiconductor film 101, and the high photostability characteristic of the photogenerated carrier quenching metal oxide semiconductor film 102, thereby reducing the difficulty of preparing the metal oxide semiconductor film 100.

[0043] Since the carrier mobility of the high-mobility metal oxide semiconductor film 101 is greater than the carrier mobility of the photo-generated carrier quenching metal oxide semiconductor film 102 , the high-mobility metal oxide semiconductor film 101 enables the metal oxide semiconductor film 100 to have high carrier mobility.

[0044] The photo-generated carrier quenching metal oxide semiconductor film 102 is used to quench the photo-generated carriers diffused from the high-mobility metal oxide semiconductor film 101, and the ratio of the difference in carrier concentration between the photo-generated carrier quenching metal oxide semiconductor film 102 under light illumination and dark state to the carrier concentration under light illumination (n photo -n dark ) / n photo ) is less than the ratio of the difference between the carrier concentration of the high mobility metal oxide semiconductor film 101 in the light state and the dark state to the carrier concentration in the light state (n photo -n dark ) / n photo ), the configuration of photogenerated carrier quenching metal oxide semiconductor film 102 makes the metal oxide semiconductor film 100 have high photostability.

[0045] Therefore, the metal oxide semiconductor film 100 provided in the embodiment of the present invention has a stacked structure composed of at least one layer of photogenerated carrier quenching metal oxide semiconductor film 102 and at least one layer of high-mobility metal oxide semiconductor film 101, so that the metal oxide semiconductor film 100 has both high carrier mobility and high photostability.

[0046] It should be noted that the metal oxide semiconductor film 100 provided in the embodiment of the present invention is used for the active layer of a thin film transistor, so the structure of a thin film transistor is taken as an example to illustrate the stacked structure of the metal oxide semiconductor film 100. Since the metal oxide semiconductor film 100 has both high carrier mobility and high light stability, when it is used as the active layer of a thin film transistor, the carrier mobility and light stability of the thin film transistor are improved. Fig.28 It is a schematic diagram of the photoresponse characteristics of a thin film transistor whose active layer material is a single layer of high-mobility oxide film.

[0047] Fig.29 This is a schematic diagram of the light response characteristics of a thin film transistor with a single-layer photogenerated carrier quenching metal oxide semiconductor film as the active layer. Fig.28 and Fig.29 It can be seen that the photogenerated carrier quenching metal oxide semiconductor film 102 can effectively reduce the influence of photogenerated carriers on the characteristics of the TFT device. In dark, 3k nits, 15k nits, 55k nits and 140k nits represent different light intensities.

[0048] Optionally, based on the above technical solution, Figure 2 As shown, Figure 2Schematic diagram of the Fermi energy levels of a high-mobility metal oxide semiconductor film and a photo-generated carrier quenching metal oxide semiconductor film, the absolute value of the difference between the Fermi energy level of the photo-generated carrier quenching metal oxide semiconductor film 102 and the Fermi energy level of the high-mobility metal oxide semiconductor film 101 relative to the vacuum Fermi energy level is less than or equal to 0.5 eV; wherein, the absolute value of the difference between the Fermi energy level of the photo-generated carrier quenching metal oxide semiconductor film 102 and the Fermi energy level of the high-mobility metal oxide semiconductor film 101 relative to the vacuum Fermi energy level is expressed as follows:

[0049] |ΔE|=|(E CBMB -E VAC )-(E CBMA -E VAC )|

[0050] Wherein, |ΔE| is the absolute value of the difference between the Fermi energy level of the photogenerated carrier quenching metal oxide semiconductor film 102 and the Fermi energy level of the high mobility metal oxide semiconductor film 101 relative to the vacuum Fermi energy level; E CBMB The Fermi level of the metal oxide semiconductor film 102 is quenched by photogenerated carriers; E CBMA is the Fermi level of the high-mobility metal oxide semiconductor film 101; E VAC is the vacuum Fermi level.

[0051] Specifically, the absolute value of the difference between the Fermi level of the photo-generated carrier quenching metal oxide semiconductor film 102 and the Fermi level of the high-mobility metal oxide semiconductor film 101 relative to the vacuum Fermi level is less than or equal to 0.5 eV. In this way, it can be ensured that the photo-generated carriers generated in the high-mobility metal oxide semiconductor film 101 can be injected into the photo-generated carrier quenching metal oxide semiconductor film 102 by using physical action quantities such as potential energy difference, thermal energy, and concentration difference. In addition, the IV characteristics can also maintain stability under strong light irradiation.

[0052] Optionally, based on the above technical solution, the thickness of the high-mobility metal oxide semiconductor film 101 is greater than or equal to 10 angstroms and less than or equal to 500 angstroms; and / or the thickness of the photogenerated carrier quenching metal oxide semiconductor film 102 is greater than or equal to 100 angstroms and less than or equal to 2000 angstroms.

[0053] Specifically, the thickness of the high-mobility metal oxide semiconductor film 101 is in the range of 10 angstroms to 500 angstroms, so that the thickness of the high-mobility metal oxide semiconductor film 101 is less than or equal to the diffusion length of the photogenerated carriers, and thus the photogenerated carriers in the high-mobility metal oxide semiconductor film 101 can diffuse to the photogenerated carrier quenching metal oxide semiconductor film 102, and the photogenerated carrier quenching metal oxide semiconductor film 102 achieves the quenching effect on the excitons. Specifically, the rare earth ions in the photogenerated carrier quenching metal oxide semiconductor film 102 have a high binding energy with oxygen, that is, the rare earth ions are relatively stable when combined with oxygen atoms, so they are usually used as inhibitors of oxygen vacancies, and oxygen vacancies are considered to be the source of the conductivity of metal oxide semiconductor materials, so the doping of rare earth ions usually leads to a decrease in the concentration of carriers, achieving the quenching effect on excitons.

[0054] The thickness of the photo-generated carrier quenching metal oxide semiconductor film 102 is greater than or equal to 100 angstroms and less than or equal to 2000 angstroms. If the thickness of the photo-generated carrier quenching metal oxide semiconductor film 102 is too thick, that is, greater than 2000 angstroms, the gate control capability of the thin film transistor will be insufficient. If the thickness of the photo-generated carrier quenching metal oxide semiconductor film 102 is too thin, that is, less than 100 angstroms, the photostability of the metal oxide semiconductor film 100 will not be high enough.

[0055] Optionally, based on the above technical solution, a photogenerated carrier quenching metal oxide semiconductor film 102 is provided on at least one surface of the high-mobility metal oxide semiconductor film 101, so that the photogenerated carrier quenching metal oxide semiconductor film 102 is used to quench the photogenerated carriers diffused from the high-mobility metal oxide semiconductor film 101 to improve the photostability of the metal oxide semiconductor film 100.

[0056] Optionally, based on the above technical solution, the stacked structure formed by the high-mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 includes any one of an AB stacked structure, a BAB stacked structure, an ABAB stacked structure and an ABBAB stacked structure; wherein A is the high-mobility metal oxide semiconductor film 101, and B is the photo-generated carrier quenching metal oxide semiconductor film 102.

[0057] Table 1 Preparation parameters and performance of metal oxide semiconductor thin film in a thin film transistor including AB stacked structure

[0058]

[0059] Table 2 Preparation parameters and performance of metal oxide semiconductor thin films in another thin film transistor including AB stacked structure

[0060]

[0061]

[0062] Table 3 Preparation parameters and performance of metal oxide semiconductor thin films in another thin film transistor including AB stacked structure

[0063]

[0064] It can be seen from Table 1 and Table 2 that the thin film transistor including the metal oxide semiconductor film of the AB stacked structure has high carrier mobility and high photostability. The absolute value of the Fermi level difference of the two films is less than 0.5eV. In the table, the meaning of ΔVth when the top light is incident is that the light is incident from the side of the passivation layer 205 away from the substrate 200 and in the dark state, and the threshold voltage (ΔVth) value of the thin film transistor changes. The meaning of ΔVth when the bottom light is incident is that the light is incident from the side of the substrate 200 away from the passivation layer 205 and in the dark state, and the threshold voltage (ΔVth) value of the thin film transistor changes. In Table 1 and Table 2, regardless of whether the light is incident from the top or the bottom, the absolute value of ΔVth is within 2V. The photostability of the whole structure device is very excellent. In the structure of Table 3, the Fermi level difference of different active layer films is greater than 0.5eV. Therefore, the light response characteristics of the final device are relatively large, indicating that the transfer of photogenerated carriers in the AB stacked structure is suppressed. As Figure 1 In the schematic diagram of the structure of the thin film transistor shown, the stacked structure composed of the high-mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 is an AB stacked structure. Figure 1 As shown, the thin film transistor includes: a substrate 200; a gate 201, which is located on one side of the substrate 200; a gate insulating layer 202, which is located on a side of the gate 201 away from the substrate 200; a metal oxide semiconductor film 100, which is located on a side of the gate insulating layer 202 away from the gate 201; a source 203, which is located on a side of the gate insulating layer 202 away from the gate 201 and covers a portion of the metal oxide semiconductor film 100; a drain 204, which is located on a side of the gate insulating layer 202 away from the gate 201 and covers a portion of the metal oxide semiconductor film 100; a passivation layer 205, which is located on a side of the metal oxide semiconductor film 100 away from the gate insulating layer 202 and covers the source 203 and the drain 204.

[0065] like Figure 3 As shown, Figure 3 yes Figure 1Schematic diagram of the transfer characteristic curve of the thin film transistor at 9 different positions. Figure 3 As can be seen from the figure, the device mobility of the thin film transistor is 66.4 cm 2 / Vs, the subthreshold swing SS is 0.26V / Dec, and the threshold voltage is -0.68V. Figure 3 The transfer characteristic curves of the thin film transistor at 9 different positions are shown. The overlap of the transfer characteristic curves at 9 different positions is very high, proving that the uniformity of each position of the thin film transistor is relatively high. Figure 4 As shown, Figure 4 yes Figure 1 The figure is a schematic diagram of the transfer characteristic curve of the thin film transistor under illumination and dark state. In the thin film transistor, when 6000 nits of light is incident from the side of the passivation layer 205 away from the substrate 200 and in the dark state, the change threshold voltage (ΔVth) value of the thin film transistor is less than 1.0V, and it has high light stability.

[0066] in, Figure 3 and Figure 4 The transfer characteristic curve diagram of the corresponding thin film transistor is as follows: on a 20um flexible polyimide (PI) film, SiN x and SiO2 stacked film as buffer layer ( Figure 1 Buffer layer not shown). SiN x The thickness of the Mo and Cu metal layer is 30nm and the thickness of the Cu metal layer is 600nm. Then, the SiN x and SiO2 as the gate insulating layer 202, SiN x The thickness of SiO2 is 250nm, and the thickness of SiO2 is 100nm; then, a high-mobility metal oxide semiconductor film 101 and a photo-generated carrier quenching metal oxide semiconductor film 102 are sequentially deposited to form an AB stacked structure. The thickness of the high-mobility metal oxide semiconductor film 101 is 5nm, and the thickness of the photo-generated carrier quenching metal oxide semiconductor film 102 is 30nm; the high-mobility metal oxide semiconductor film 101 is prepared by ALD equipment.

[0067] like Figure 5 In the schematic diagram of the structure of the thin film transistor shown in FIG. Figure 5 It is a schematic diagram of the structure of another thin film transistor provided by an embodiment of the present invention, in which the stacked structure composed of the high-mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 is an ABBAB stacked structure. Figure 5 The thin film transistor and Figure 1The difference between the thin film transistors shown is that the stacked structure composed of the high-mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 is an ABBAB stacked structure. The increase in the number of layers of the photo-generated carrier quenching metal oxide semiconductor film 102 further improves the light stability of the thin film transistor; the increase in the number of layers of the high-mobility metal oxide semiconductor film 101 further improves the carrier mobility of the thin film transistor.

[0068] like Figure 6 In the schematic diagram of the structure of the thin film transistor shown in FIG. Figure 6 1 is a schematic diagram of the structure of another thin film transistor provided by an embodiment of the present invention, wherein the stacked structure formed by the high mobility metal oxide semiconductor film 101 and the photogenerated carrier quenching metal oxide semiconductor film 102 is a BAB stacked structure. Figure 6 As shown, the thin film transistor includes a substrate 200; a buffer layer 300, the buffer layer 300 is located on one side of the substrate 200; a metal oxide semiconductor film 100, the metal oxide semiconductor film 100 is located on the side of the buffer layer 300 away from the substrate 200; a gate insulating layer 202, the gate insulating layer 202 is located on the side of the metal oxide semiconductor film 100 away from the buffer layer 300; a gate 201, the gate 201 is located on the side of the gate insulating layer 202 away from the metal oxide semiconductor film 100; an interlayer insulating layer 400, the interlayer insulating layer 400 is located on the side of the gate 201 away from the metal oxide semiconductor film 100, the interlayer insulating layer 400 also covers the side of the gate 201 and the side of the gate insulating layer 202, and the interlayer insulating layer 400 is provided with a first through hole T1 and a second through hole T2. Through hole T2, the first through hole T1 exposes part of the surface of the metal oxide semiconductor film 100, and the second through hole T2 exposes part of the surface of the metal oxide semiconductor film 100; source electrode 203, the source electrode 203 is located on the side of the interlayer insulating layer 400 away from the substrate 200, the source electrode 203 reaches the metal oxide semiconductor film 100 through the first through hole T1, and is electrically connected to the metal oxide semiconductor film 100; drain electrode 204, the drain electrode 204 is located on the side of the interlayer insulating layer 400 away from the substrate 200, the drain electrode 204 reaches the metal oxide semiconductor film 100 through the second through hole T2, and is electrically connected to the metal oxide semiconductor film 100; passivation layer 205, the passivation layer 205 is located on the side of the source electrode 203 and the drain electrode 204 away from the substrate 200, and covers the interlayer insulating layer 400. It should be noted that in other optional embodiments, it is also possible to Figure 5 and Figure 6 The thin film transistor shown in the figure is provided with a high-mobility metal oxide semiconductor film 101 and a photo-generated carrier quenching metal oxide semiconductor film 102 having more layers.

[0069] Figure 7 yes Figure 6 A schematic diagram of a transfer characteristic curve of a thin film transistor under light and dark conditions. Figure 8 yes Figure 6 Another transfer characteristic curve diagram of a thin film transistor in light and dark states. Figure 7 In the embodiment, light is incident from the substrate 200 side. Figure 8 In the embodiment, light is incident from the side of the passivation layer 205 .

[0070] like Figure 7 and Figure 8 As shown, in this thin film transistor, the device mobility is 82.4 cm 2 / Vs, subthreshold swing SS is 0.31V / Dec, threshold voltage is -0.91V; when 6000nits of light is incident on the side of the passivation layer 205 away from the substrate 200 and in the dark state, the change threshold voltage (ΔVth) value of the thin film transistor is less than 2.0V, and it has high light stability. When 6000nits of light is incident on the side of the substrate 200 away from the passivation layer 205 and in the dark state, the change threshold voltage (ΔVth) value of the thin film transistor is less than 0.5V, and it has high light stability.

[0071] in, Figure 7 and Figure 8 The preparation method of the thin film transistor corresponding to the transfer characteristic curve diagram is as follows: On a 0.5 mm glass substrate 200, a SiO2 film is prepared as a buffer layer 300. The thickness of SiO2 is 400 nm. Then, a BAB stacked structure of a photo-generated carrier quenching metal oxide semiconductor film 102, a high-mobility metal oxide semiconductor film 101 and a photo-generated carrier quenching metal oxide semiconductor film 102 is sequentially formed on the buffer layer 300. The thickness of the high-mobility metal oxide semiconductor film 101 is 20 nm, the thickness of the photo-generated carrier quenching metal oxide semiconductor film 102 on the side close to the substrate 200 is 10 nm, and the thickness of the photo-generated carrier quenching metal oxide semiconductor film 102 on the side close to the passivation layer 205 is 80 nm. The high-mobility metal oxide semiconductor film 101 is prepared by ALD equipment.

[0072] like Fig. 9 In the schematic diagram of the structure of the thin film transistor shown in FIG. Fig. 9 1 is a schematic diagram of the structure of another thin film transistor provided by an embodiment of the present invention. The stacked structure composed of the high mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 is an ABAB stacked structure. The photo-generated carrier quenching metal oxide semiconductor film 102 on the side close to the substrate 200 is In 0.200 Zn 0.500 Ga0.250 Dy 0.050 O, deposited by PVD sputtering equipment. The sputtering pressure of the PVD sputtering process is 0.3 mTorr, and the Ar / O ratio is 40%. The photogenerated carrier quenching metal oxide semiconductor film 102 near the passivation layer 205 is Zn 0.500 Ga 0442 Ti 0.008 Dy 0.050 O, deposited using PVD sputtering equipment. The sputtering pressure of the PVD sputtering process is 0.7mTorr, and the Ar / O ratio is 60%. Then oxalic acid is used to etch and pattern at room temperature to form an island-shaped active layer. Then SiO2 is deposited as the gate insulating layer 202 with a thickness of 150nm; then metal Mo is deposited as the gate 201 with a thickness of 200nm; then SiO2 with a thickness of 300nm is deposited and patterned using dry etching as the interlayer insulating layer 400; then TiAlTi laminated electrodes are made on the interlayer insulating layer 400, and patterned using dry etching as the source 203 and drain 204. The thickness of the Ti metal layer on both sides of the Al metal layer is 30nm, and the thickness of the Al metal layer is 500nm. Then a laminated insulating film of SiO2 and SiNx is deposited as the passivation layer 205, with a thickness of 300nm for SiO2 and a thickness of 100nm for SiNx; the device is finally annealed at 350℃ for 1 hour to complete the TFT device manufacturing.

[0073] Optionally, based on the above technical solution, Figure 1 As shown, the chemical formula of the high mobility metal oxide semiconductor film 101 is (MO) x (NO) y , wherein 0.4≤x≤1, 0≤y≤0.6, x+y=1; M includes one element selected from In, Sn, and Ga, or any combination of at least two elements; N includes one element selected from Zn, Ga, Si, Al, Mo, W, Sc, Y, Hf, Zr, Ta, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Yb, Sb, and Bi, or any combination of at least two elements.

[0074] Specifically, the conduction band bottom of metal oxides represented by Ga2O3, SnO2 and In2O3 is mainly composed of ns electron orbits of metal ions. The spherical ns electron orbits can make it still have a high electron orbit overlap in the amorphous disordered state, so that it has a sufficient number of carriers. Therefore, when M includes one element of In, Sn, Ga or any combination of at least two elements, a suitable process can be selected to make the high-mobility metal oxide semiconductor film 101 have a relatively high carrier mobility. The oxides formed by the corresponding elements of Zn, Ga, Si, Al, Mo, W, Sc, Y, Hf, Zr, Ta, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Yb, Sb and Bi can increase the stability of the high-mobility metal oxide semiconductor film 101, so that it has a certain degree of electrical and optical stability.

[0075] Optionally, based on the above technical solution, Figure 1 As shown, the chemical formula of the photo-generated carrier quenching metal oxide semiconductor film 102 is (M'O) x’ (N'O) y’ , wherein 0.950≤x'≤0.9998, 0.0002≤y'≤0.050, x'+y'=1; M' includes one element or any combination of at least two elements selected from In, Zn, Ga, Sn, Zr, Ta, Ti, and Hf; and N' includes one element or any combination of at least two elements selected from Ce, Pr, Tb, Dy, and Yb.

[0076] Rare earth ions have a high binding energy with oxygen, which means that the rare earth ions are relatively stable when combined with oxygen atoms, so they are usually used as inhibitors of oxygen vacancies. Oxygen vacancies are considered to be the source of conductivity of metal oxide semiconductor materials, so doping with rare earth ions usually leads to a decrease in the concentration of carriers.

[0077] Specifically, Ce, Pr, Tb, Dy, and Yb are rare earth elements. The oxides formed by Ce, Pr, Tb, Dy, and Yb utilize the valence change ability of rare earth ions and appropriate energy level matching to achieve rapid recombination of photogenerated carriers, thereby enabling the photogenerated carrier quenching metal oxide semiconductor film 102 to achieve quenching of photogenerated carriers, thereby having high light stability, thereby reducing the impact of light on the performance of thin film transistor devices. The oxides formed by In, Zn, Ga, Sn, Zr, Ta, Ti, and Hf elements can enable the photogenerated carrier quenching metal oxide semiconductor film 102 to have a certain carrier mobility.

[0078] Optionally, the photo-generated carrier quenching metal oxide semiconductor film 102 may preferably have, but not limited to, the following ratios: In 0.332 Ga0.332 Zn 0.332 Yb 0.005 O、In 0.476 Ga 0.238 Sn 0.238 Tb 0.0476 O、In 0.485 Ga 0.485 Ti 0.005 Dy 0.0243 O、In 0.485 Ga 0.485 Ti 0.005 Dy 0.0243 O.Ga 0.737 Zn 0.246 Hf 0.002 Pr 0.0147 O.

[0079] Optionally, based on the above technical solution, Figure 1 As shown, the preparation method of the high-mobility metal oxide semiconductor film 101 includes any one of atomic layer deposition, physical vapor deposition and pulsed laser deposition.

[0080] Specifically, by using any one of atomic layer deposition, physical vapor deposition and pulsed laser deposition to prepare the high-mobility metal oxide semiconductor film 101, a highly dense and highly conformal oxide film can be obtained. At the same time, the thickness of the film can also be accurately controlled, so that the high-mobility metal oxide semiconductor film 101 has a high carrier mobility.

[0081] Optionally, based on the above technical solution, Figure 1 As shown, the preparation method of the photo-generated carrier quenching metal oxide semiconductor film 102 includes at least one of physical vapor deposition, solution deposition and pulsed laser deposition.

[0082] Specifically, the photogenerated carrier quenching metal oxide semiconductor film 102 is prepared by using at least one of physical vapor deposition, solution deposition and pulsed laser deposition. There are many types of oxide semiconductors that can be prepared, especially the oxide semiconductors of rare earth metals are relatively mature, and the photostability of rare earth ions can be well exerted, so that the photogenerated carrier quenching metal oxide semiconductor film 102 has high photostability. Optionally, based on the above technical solution, the carrier mobility of the high-mobility metal oxide semiconductor film 101 is greater than or equal to 30cm 2 / Vs.

[0083] Specifically, the carrier mobility of the high-mobility metal oxide semiconductor film 101 is greater than or equal to 30 cm 2 / Vs, so that the thin film transistor has high carrier mobility.

[0084] Optionally, based on the above technical solution, the carrier concentration of the high-mobility metal oxide semiconductor film 101 is on the order of 10 17 ~10 20 / cubic centimeter; and / or, the order of magnitude of the carrier concentration of the photogenerated carrier quenching metal oxide semiconductor film 102 is 10 16 ~10 19 Pieces / cubic meter.

[0085] Specifically, the carrier concentration of the high-mobility metal oxide semiconductor film 101 is on the order of 10 17 ~10 20 Preferably, the carrier concentration of the high-mobility metal oxide semiconductor film 101 is greater than the carrier concentration of the photogenerated carrier quenching metal oxide semiconductor film 102, so that the high-mobility metal oxide semiconductor film 101 has high carrier mobility.

[0086] The embodiment of the present invention further provides a thin film transistor. The active layer of the thin film transistor adopts the metal oxide semiconductor thin film 100 described in any of the embodiments of the present invention. Therefore, the thin film transistor has both high carrier mobility and high light stability. Optionally, based on the above technical solution, as Figure 1 As shown, the thin film transistor includes: a substrate 200; a gate 201, which is located on one side of the substrate 200; a gate insulating layer 202, which is located on a side of the gate 201 away from the substrate 200; a metal oxide semiconductor film 100, which is located on a side of the gate insulating layer 202 away from the gate 201; a source 203, which is located on a side of the gate insulating layer 202 away from the gate 201 and covers a portion of the metal oxide semiconductor film 100; a drain 204, which is located on a side of the gate insulating layer 202 away from the gate 201 and covers a portion of the metal oxide semiconductor film 100; a passivation layer 205, which is located on a side of the metal oxide semiconductor film 100 away from the gate insulating layer 202 and covers the source 203 and the drain 204.

[0087] Exemplarily, the stacked structure formed by the high-mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 includes an AB stacked structure.

[0088] Optionally, based on the above technical solution, Figure 6As shown, the thin film transistor includes a substrate 200; a buffer layer 300, the buffer layer 300 is located on one side of the substrate 200; a metal oxide semiconductor film 100, the metal oxide semiconductor film 100 is located on the side of the buffer layer 300 away from the substrate 200; a gate insulating layer 202, the gate insulating layer 202 is located on the side of the metal oxide semiconductor film 100 away from the buffer layer 300; a gate 201, the gate 201 is located on the side of the gate insulating layer 202 away from the metal oxide semiconductor film 100; an interlayer insulating layer 400, the interlayer insulating layer 400 is located on the side of the gate 201 away from the metal oxide semiconductor film 100, the interlayer insulating layer 400 also covers the side of the gate 201 and the side of the gate insulating layer 202, and the interlayer insulating layer 400 is provided with a first through hole T1 and a second through hole T2. Hole T2, the first through hole T1 exposes a portion of the surface of the metal oxide semiconductor film 100, and the second through hole T2 exposes a portion of the surface of the metal oxide semiconductor film 100; the source 203, the source 203 is located on the side of the interlayer insulating layer 400 away from the substrate 200, the source 203 reaches the metal oxide semiconductor film 100 through the first through hole T1, and is electrically connected to the metal oxide semiconductor film 100; the drain 204, the drain 204 is located on the side of the interlayer insulating layer 400 away from the substrate 200, the interlayer insulating layer 400 reaches the metal oxide semiconductor film 100 through the second through hole T2, and is electrically connected to the metal oxide semiconductor film 100; the passivation layer 205, the passivation layer 205 is located on the side of the source 203 and the drain 204 away from the substrate 200, and covers the interlayer insulating layer 400.

[0089] Exemplarily, the stacked structure formed by the high-mobility metal oxide semiconductor film 101 and the photo-generated carrier quenching metal oxide semiconductor film 102 is a BAB stacked structure.

[0090] It should be noted that, in other optional embodiments, Figure 6 The thin film transistor shown in the figure is provided with a high-mobility metal oxide semiconductor film 101 and a photo-generated carrier quenching metal oxide semiconductor film 102 having more layers.

[0091] Optionally, based on the above technical solution, Fig.10 As shown, Fig.10 It is a schematic diagram of the structure of another thin film transistor provided by an embodiment of the present invention. The thin film transistor further includes a light shielding layer 500 , and the light shielding layer 500 is located between the substrate 200 and the buffer layer 300 .

[0092] Optionally, the light shielding layer 500 may be a metal conductive layer. The light shielding layer 500 is located between the substrate 200 and the buffer layer 300, and increases the light stability of the bottom side of the thin film transistor when it is exposed to light.

[0093] The present invention also provides a method for preparing a thin film transistor. Figure 1 The thin film transistor shown, as Fig.11 As shown, Fig.11 1 is a flow chart of a method for preparing a thin film transistor provided by an embodiment of the present invention. The method for preparing the thin film transistor is as follows:

[0094] S110, preparing and patterning a metal conductive layer on the substrate as a gate.

[0095] like Fig.12 As shown, a metal conductive layer is prepared and patterned on a substrate 200 to serve as a gate 201 .

[0096] S120, depositing a first insulating film on the metal conductive layer as a gate insulating layer.

[0097] like Fig.13 As shown, a first insulating film is deposited on the metal conductive layer as a gate insulating layer 202 .

[0098] S130, forming a metal oxide semiconductor film on the gate insulating layer and patterning it as an active layer.

[0099] like Fig.14 As shown, a stacked structure consisting of at least one high-mobility metal oxide semiconductor film 101 and at least one photo-generated carrier quenching metal oxide semiconductor film 102 is deposited on the gate insulating layer 202. The stacked structure is a metal oxide semiconductor film 100, which is used as an active layer after patterning. Exemplarily, the stacked structure includes an AB stacked structure, A is the high-mobility metal oxide semiconductor film 101, and B is the photo-generated carrier quenching metal oxide semiconductor film 102.

[0100] Optionally, the preparation method of the high-mobility metal oxide semiconductor film 101 includes any one of atomic layer deposition, physical vapor deposition and pulsed laser deposition. The preparation method of the photogenerated carrier quenching metal oxide semiconductor film 102 includes at least one of physical vapor deposition, solution deposition and pulsed laser deposition.

[0101] S140 , depositing a metal layer on the active layer and then patterning it to serve as a source and a drain.

[0102] like Fig.15 As shown, a metal layer is deposited on the active layer and then patterned to form a source 203 and a drain 204 .

[0103] S150 , depositing a second insulating film on the source and drain as a passivation layer.

[0104] like Figure 1As shown, a second insulating film is deposited on the source electrode 203 and the drain electrode 204 as a passivation layer 205 .

[0105] The present invention also provides another method for preparing a thin film transistor. Figure 6 The thin film transistor shown, as Fig.16 As shown, Fig.16 1 is a flow chart of a method for preparing a thin film transistor provided by an embodiment of the present invention. The method for preparing the thin film transistor is as follows:

[0106] S210 , depositing a first insulating film on the substrate as a buffer layer.

[0107] like Fig.17 As shown, a first insulating film is deposited on the substrate 200 as a buffer layer 300 .

[0108] S220, forming a metal oxide semiconductor film on the buffer layer, and patterning it as an active layer.

[0109] like Fig.17 As shown, a stacked structure consisting of at least one high-mobility metal oxide semiconductor film 101 and at least one photo-generated carrier quenching metal oxide semiconductor film 102 is deposited on the buffer layer 300. The stacked structure is the metal oxide semiconductor film 100, which is used as an active layer after patterning. Exemplarily, the stacked structure includes a BAB stacked structure, A is the high-mobility metal oxide semiconductor film 101, and B is the photo-generated carrier quenching metal oxide semiconductor film 102.

[0110] Optionally, the preparation method of the high-mobility metal oxide semiconductor film 101 includes any one of atomic layer deposition, physical vapor deposition and pulsed laser deposition. The preparation method of the photogenerated carrier quenching metal oxide semiconductor film 102 includes at least one of physical vapor deposition, solution deposition and pulsed laser deposition.

[0111] S230 , depositing a second insulating layer on the active layer as a gate insulating layer.

[0112] like Fig.18 As shown, a second insulating layer is deposited on the active layer as a gate insulating layer 202 .

[0113] S240 , depositing a metal layer on the gate insulating layer and then patterning it to form a gate.

[0114] like Fig.19 As shown, a metal layer is deposited on the gate insulating layer 202 and then patterned to form the gate 201 .

[0115] S250, depositing a third insulating film on the metal conductive layer, and then patterning it as an interlayer insulating layer.

[0116] like Fig. 20 As shown, a third insulating film is deposited on the metal conductive layer and then patterned as an interlayer insulating layer 400 to form a first through hole T1 and a second through hole T2.

[0117] S260 , depositing a metal layer on the interlayer insulating layer and then patterning it to serve as a source and a drain.

[0118] like Fig.21 As shown, a metal layer is deposited on the interlayer insulating layer 400 and then patterned to form the source 203 and the drain 204 .

[0119] S270 , depositing a fourth insulating film on the source and drain as a passivation layer.

[0120] like Figure 6 As shown, a fourth insulating film is deposited on the source electrode 203 and the drain electrode 204 as a passivation layer 205 .

[0121] The present invention also provides another method for preparing a thin film transistor. Fig.10 The thin film transistor shown, as Fig. 22 As shown, Fig. 22 1 is a flow chart of a method for preparing a thin film transistor provided by an embodiment of the present invention. The method for preparing the thin film transistor is as follows:

[0122] S310, preparing and patterning a metal conductive layer on a substrate as a light shielding layer.

[0123] like Fig.23 As shown, a metal conductive layer is prepared and patterned on a substrate 200 as a light shielding layer 500 .

[0124] S320 , depositing a first insulating film on the light shielding layer as a buffer layer.

[0125] like Fig.23 As shown, a first insulating film is deposited on the light shielding layer 500 as the buffer layer 300 .

[0126] S330, forming a metal oxide semiconductor film on the buffer layer and patterning it as an active layer.

[0127] like Fig.23 As shown, a stacked structure consisting of at least one high-mobility metal oxide semiconductor film 101 and at least one photo-generated carrier quenching metal oxide semiconductor film 102 is deposited on the buffer layer 300. The stacked structure is the metal oxide semiconductor film 100, which is used as an active layer after patterning. Exemplarily, the stacked structure includes a BAB stacked structure, A is the high-mobility metal oxide semiconductor film 101, and B is the photo-generated carrier quenching metal oxide semiconductor film 102.

[0128] Optionally, the preparation method of the high-mobility metal oxide semiconductor film 101 includes any one of atomic layer deposition, physical vapor deposition and pulsed laser deposition. The preparation method of the photogenerated carrier quenching metal oxide semiconductor film 102 includes at least one of physical vapor deposition, solution deposition and pulsed laser deposition.

[0129] S340 , depositing a second insulating layer on the active layer as a gate insulating layer.

[0130] like Fig.24 As shown, a second insulating layer is deposited on the active layer as a gate insulating layer 202 .

[0131] S350 , depositing a metal layer on the gate insulating layer and then patterning it to form a gate.

[0132] like Fig.25 As shown, a metal layer is deposited on the gate insulating layer 202 and then patterned to form the gate 201 .

[0133] S360, depositing a third insulating film on the metal conductive layer, and then patterning it as an interlayer insulating layer.

[0134] like Fig.26 As shown, a third insulating film is deposited on the metal conductive layer and then patterned as an interlayer insulating layer 400 to form a first through hole T1 and a second through hole T2.

[0135] S370 , depositing a metal layer on the interlayer insulating layer and then patterning it to serve as a source and a drain.

[0136] like Fig. 27 As shown, a metal layer is deposited on the interlayer insulating layer 400 and then patterned to form the source 203 and the drain 204 .

[0137] S380 , depositing a fourth insulating film on the source and drain as a passivation layer.

[0138] like Fig.10 As shown, a fourth insulating film is deposited on the source electrode 203 and the drain electrode 204 as a passivation layer 205 .

[0139] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0140] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A metal oxide semiconductor film, characterized in that: include: At least one high-mobility metal oxide semiconductor film; At least one layer of photo-generated carrier quenching metal oxide semiconductor film, wherein the photo-generated carrier quenching metal oxide semiconductor film and the high-mobility metal oxide semiconductor film form a stacked structure; the photo-generated carrier quenching metal oxide semiconductor film is used to quench photo-generated carriers; The carrier mobility of the high-mobility metal oxide semiconductor film is greater than the carrier mobility of the photogenerated carrier quenching metal oxide semiconductor film; The ratio of the difference between the carrier concentration of the photogenerated carrier quenching metal oxide semiconductor film under illumination and under dark conditions to the carrier concentration under illumination is less than the ratio of the difference between the carrier concentration of the high-mobility metal oxide semiconductor film under illumination and under dark conditions to the carrier concentration under illumination.

2. The metal oxide semiconductor thin film according to claim 1, characterized in that: The absolute value of the difference between the Fermi energy level of the photogenerated carrier quenching metal oxide semiconductor film and the Fermi energy level of the high mobility metal oxide semiconductor film relative to the vacuum Fermi energy level is less than or equal to 0.5 eV; The absolute value of the difference between the Fermi energy level of the photogenerated carrier quenching metal oxide semiconductor film and the Fermi energy level of the high mobility metal oxide semiconductor film relative to the vacuum Fermi energy level is expressed as follows: |ΔE|=|(E CBMB -E VAC )-(E CBMA -E VAC )| Wherein, |ΔE| is the absolute value of the difference between the Fermi energy level of the photogenerated carrier quenching metal oxide semiconductor film and the Fermi energy level of the high mobility metal oxide semiconductor film relative to the vacuum Fermi energy level; E CBMB The photogenerated carriers quench the Fermi level of the metal oxide semiconductor film; E CBMA is the Fermi level of the high mobility metal oxide semiconductor film; E VAC is the vacuum Fermi level.

3. The metal oxide semiconductor thin film according to claim 1, characterized in that: The thickness of the high-mobility metal oxide semiconductor film is greater than or equal to 10 angstroms and less than or equal to 500 angstroms; and / or the thickness of the photogenerated carrier quenching metal oxide semiconductor film is greater than or equal to 100 angstroms and less than or equal to 2000 angstroms.

4. The metal oxide semiconductor thin film according to claim 1, characterized in that: The photogenerated carrier quenching metal oxide semiconductor film is disposed on at least one surface of the high-mobility metal oxide semiconductor film.

5. The metal oxide semiconductor thin film according to claim 4, characterized in that: The stacked structure formed by the high-mobility metal oxide semiconductor film and the photogenerated carrier quenching metal oxide semiconductor film includes any one of an AB stacked structure, a BAB stacked structure, an ABAB stacked structure and an ABBAB stacked structure; Wherein, A is the high-mobility metal oxide semiconductor film, and B is the photogenerated carrier quenching metal oxide semiconductor film.

6. The metal oxide semiconductor thin film according to claim 1, characterized in that: The chemical formula of the high mobility metal oxide semiconductor film is (MO) x (NO) y , where 0.4≤x≤1, 0≤y≤0.6, x+y=1; M includes one element of In, Sn, and Ga, or any combination of at least two elements; N includes one element or any combination of at least two elements selected from the group consisting of Zn, Ga, Si, Al, Mo, W, Sc, Y, Hf, Zr, Ta, La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Yb, Sb and Bi.

7. The metal oxide semiconductor thin film according to claim 1, characterized in that: The chemical formula of the photogenerated carrier quenching metal oxide semiconductor film is (M'O) x’ (N'O) y’ , where 0.950≤x'≤0.9998, 0.0002≤y'≤0.050, x'+y'=1; M' includes one element or any combination of at least two elements selected from In, Zn, Ga, Sn, Zr, Ta, Ti, and Hf; N' includes one element or any combination of at least two elements selected from Ce, Pr, Tb, Dy, and Yb.

8. The metal oxide semiconductor thin film according to claim 1, characterized in that: The carrier concentration of the high mobility metal oxide semiconductor film is on the order of 10 17 ~10 20 pcs / cubic centimeter; And / or, the photogenerated carrier quenching metal oxide semiconductor film carrier concentration is on the order of 10 16 ~10 19 Pieces / cubic centimeter.

9. The metal oxide semiconductor thin film according to claim 1, characterized in that: The carrier mobility of the high-mobility metal oxide semiconductor film is greater than or equal to 30 cm 2 / Vs.

10. A thin film transistor, characterized in that: The invention comprises the metal oxide semiconductor film as described in any one of claims 1 to 9.

Images