A high mobility indium gallium zinc oxide composite thin film transistor and a preparation method thereof

Abstract

The present application provides a kind of indium gallium zinc terbium oxide composite thin film transistor and preparation method thereof, the composite thin film transistor uses indium salt, gallium salt, zinc salt and terbium salt to make mixed solution in preparation process, carbon nanotube is ultrasonically dissolved in ethylene glycol methyl ether, and is uniformly suspended as mother liquor by ultrasonic, the mother liquor is added to the mixed solution, and the mobility of the composite thin film transistor device is prepared to reach 130cm 2 / V·s.The present application also provides a kind of top gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor and preparation method thereof, the composite thin film is prepared according to the preparation method of the above-mentioned indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor, and the mobility of the top gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor reaches 60cm 2 / V·s.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of semiconductor display devices and microelectronics technology, and particularly relates to a low-on-state current and high-mobility indium-gallium-zinc-terbium oxide-based composite thin film transistor and a preparation method thereof. BACKGROUND

[0002] China's new display functional device industry scale is the largest in the world, with an annual growth of more than 20%. In 2021, the display industry output value in China reached about 586.8 billion yuan, providing continuous momentum for the global industry chain. However, the flat panel display industry in Japan and South Korea is already mature, and famous flat panel display companies such as Sony, Sharp, Samsung, LG, AUO, and CMO are leading the global flat panel display market. At the 2020 World Display Industry Conference, industry associations from China, Japan, and South Korea launched the "New Display Industry Global Cooperation Initiative", calling for global cooperation in new display technology and promoting high-quality development of the industry.

[0003] The application range of metal oxide thin film transistors has been extended from the original display panel industry to system-on-panel design. Thin film transistors (TFTs) as switching elements in active array driving display devices have become the best in many flat panel display technologies. TFT is a kind of field effect semiconductor device, which includes substrate, semiconductor channel layer, insulating layer, gate and source-drain electrode, etc., and the semiconductor channel layer is crucial to the performance of the device. In addition, the dynamic response characteristics of the device in integrated circuits are also very important, especially for current displays that are developing towards high resolution and high frame rate, which requires higher working speed of the device. Therefore, TFTs in the circuit need to have higher carrier mobility, which is one of the biggest bottlenecks restricting the development of oxides. While traditional oxide semiconductor thin films face the bottleneck of mobility (20 cm 2 / V·s), there are also problems such as negative bias temperature illumination stress (NBTIS) instability, which limit the driving of high-definition display devices and the stability of the device.

[0004] Therefore, it is urgent to solve the trade-off between the mobility and stability of thin film transistors (TFTs) and the compatibility of the preparation process, in order to meet the needs of future low-power circuit development. SUMMARY

[0005] The purpose of the present application is to solve the problems of the prior art, and to provide a composite thin film transistor and a preparation method thereof.

[0006] To solve the above technical problems, the present application provides a high-performance thin film transistor, which uses an amorphous indium-gallium-zinc-terbium oxide / carbon nanotube composite thin film as a semiconductor channel layer, and specifically adopts the following technical solutions:

[0007] In a first aspect, the present application provides an indium gallium zinc terbium oxide composite thin film transistor, which is prepared by using indium salt, gallium salt, zinc salt and terbium salt to make a mixed solution, dissolving carbon nanotubes in ethylene glycol methyl ether by ultrasonic, making the carbon nanotubes uniformly suspended as a mother liquor, adding the mother liquor into the mixed solution, and treating to obtain the composite thin film transistor, wherein the mobility of the composite thin film transistor device reaches 130 cm 2 / V·s.

[0008] Preferably, the maximum on-state current of the composite thin film transistor device reaches 0.8 mA.

[0009] Preferably, the carbon atoms and metal cations in the oxide have a molar ratio of 20%-30%.

[0010] Preferably, the carbon atoms and metal cations in the oxide have a molar ratio of 25%.

[0011] In a second aspect, the present application provides a preparation method of an indium gallium zinc terbium oxide composite thin film transistor, which comprises the following steps:

[0012] Step one, adding stabilizer ethanolamine into ethylene glycol methyl ether to obtain a solution A0;

[0013] Step two, adding indium salt, gallium salt, zinc salt and terbium salt into the solution A0 as precursors, and stirring for a certain time to form a mixed solution;

[0014] Step three, dissolving carbon nanotubes in ethylene glycol methyl ether by ultrasonic, making the carbon nanotubes uniformly suspended as a mother liquor, and recording as a solution A CNT Step four, adding the solution A CNT into the above mixed solution, and continuing to ultrasonic to make the carbon nanotubes uniformly dispersed in the mixed solution;

[0015] Step four, spin coating the solution obtained in step three on a substrate pre-grown with an insulating layer, drying, and then repeating the spin coating until the desired thickness is reached;

[0016] Step five, thermal annealing, to obtain an indium gallium zinc terbium oxide / carbon nanotube composite thin film material;

[0017] Step six, treating the composite thin film material to obtain an indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor.

[0018] Preferably, the insulating layer is a SiO2 insulating layer.

[0019] In a third aspect, the present application provides a top-gate indium gallium zinc terbium oxide composite thin film transistor, which comprises a top-gate electrode, a gate insulating layer, an indium gallium zinc terbium oxide / carbon nanotube composite thin film, a substrate and a metal contact electrode, wherein the indium gallium zinc terbium oxide / carbon nanotube composite thin film is prepared according to the method described above, and the top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor has a mobility of 60 cm 2 / V·s.

[0020] In a fourth aspect, the present application provides a preparation method of a top-gate indium gallium zinc terbium oxide composite thin film transistor, which is used to prepare the indium gallium zinc terbium oxide / carbon nanotube composite thin film material according to the method described above.

[0021] A back-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor is obtained by using ultraviolet lithography technology, mask, evaporation and stripping.

[0022] A medium layer is prepared, and the top-gate insulating layer is patterned by using lithography technology to realize the preparation of the gate electrode, so as to obtain the top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor.

[0023] Preferably, the molar ratio of terbium to the total amount of indium, gallium and zinc is 1:9.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] (1) The present application provides an indium gallium zinc terbium oxide thin film transistor and a preparation method thereof. Experimental tests show that the combination of gallium elements and indium zinc terbium elements can effectively regulate the threshold voltage of the indium gallium zinc terbium oxide thin film transistor.

[0026] (2) The present application uses metal oxide thin film as a basic material, and a small amount of metallic carbon nanotubes are compounded in the thin film. The high carrier mobility of the carbon nanotubes is used to improve the on-state current, mobility and mechanical flexibility of the amorphous metal oxide thin film. At the same time, a small amount of terbium elements are doped to improve the electrical bias stability of the device. The composite thin film is used as a semiconductor channel layer, and a high-mobility and high-stability oxide / carbon nanotube composite thin film field effect transistor is obtained through a transistor manufacturing process. Through accurate control of the channel layer material composition, the threshold voltage of the transistor is regulated to meet the needs of various applications.

[0027] (3) The prepared indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor has a maximum on-state current of 0.8 mA, and a mobility of 130 cm 2 / V·s. It can be seen that the prepared indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor has high mobility and on-state current.

[0028] (4) The top-gate indium gallium zinc oxide / carbon nanotube composite thin film transistor prepared by the method has a mobility of 60 cm 2 / V·s. The indium gallium zinc oxide / carbon nanotube composite thin film transistor prepared by the method has high mobility and high stability. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Device structure in Example 1 and Example 2;

[0030] Figure 2 Electrical transfer characteristic curve of the indium gallium zinc oxide thin film transistor with different Ga contents in Example 1;

[0031] Figure 3 Transfer characteristic curve of the indium gallium zinc oxide thin film transistor device prepared in Example 1;

[0032] Figure 4 Electrical performance curve of the indium gallium zinc oxide / carbon nanotube composite thin film transistor prepared in Example 2;

[0033] Figure 5 (a) is a cross-sectional schematic view of the top-gate indium gallium zinc oxide / carbon nanotube composite thin film transistor prepared in Example 3; Figure 5 (b) and Figure 5 (c) is a performance curve of the top-gate indium gallium zinc oxide / carbon nanotube composite thin film transistor prepared in Example 3;

[0034] Figure 6 Test performance curve of the top-gate indium gallium zinc oxide / carbon nanotube composite thin film transistor with different terbium contents prepared in Example 3. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0036] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0037] The present application will be further described below with reference to specific embodiments, but is not limited to the embodiments.

[0038] Example 1

[0039] The embodiment of the present application provides a preparation method of an indium gallium zinc terbium oxide thin film transistor with different gallium (Ga) contents, and specifically comprises the following steps.

[0040] In step one, a stabilizer ethanolamine is added into ethylene glycol methyl ether, and the solution is recorded as A0.

[0041] Preferably, the stabilizer ethanolamine is added into the ethylene glycol methyl ether at a volume ratio of 0.92%.

[0042] In step two, indium nitrate, gallium nitrate, zinc acetate and terbium acetate are added into the solution A0 as precursors in different molar ratios of In:Ga:Zn:Tb, and after stirring for a certain time, a mixed solution is formed.

[0043] Preferably, the total molar concentration of all metal cations in the final composite solution is controlled to be 0.03 mol / L.

[0044] Preferably, the indium nitrate, gallium nitrate, zinc acetate and terbium acetate with the molar ratio of In:Ga:Zn:Tb=3:x:3:1 (x=0, 1, 2, 3, 4, 6) are added into 100 ml of the solution A0 as precursors. The stirring time is 2 hours, and a uniform mixed solution is formed.

[0045] In step three, the mixed solution obtained in step two is spin-coated on a substrate pre-grown with a SiO2 insulating layer, and after drying, spin-coating is continuously performed, and the operation is repeated until the required thickness is reached.

[0046] Preferably, the thickness of the SiO2 insulating layer is 100 nm.

[0047] In step four, thermal annealing is performed in the atmosphere, and an indium gallium zinc terbium oxide composite thin film material is obtained.

[0048] In step five, the indium gallium zinc terbium oxide composite thin film material is processed, and an indium gallium zinc oxide composite thin film transistor with different gallium (Ga) contents is obtained.

[0049] Specifically, by using the ultraviolet lithography technology, the composite thin film is etched into independent small blocks by using the first mask and wet etching, so that the leakage current is reduced; then, the channel length / width is 15 μm / 75 μm by using the second mask, and the contact electrode is evaporated and peeled off, so that the indium gallium zinc terbium oxide thin film transistor with different gallium (Ga) contents is obtained, as shown in Figure 1 .

[0050] The embodiment one of the present application provides a preparation method of an indium gallium zinc terbium oxide thin film transistor, Figures 2-3 The test results of the indium gallium zinc terbium oxide thin film transistor obtained according to the preparation method are shown.

[0051] The indium gallium zinc terbium oxide thin film transistor obtained according to the preparation method has the following advantages: Figure 2The electrical transfer curve test results of the indium gallium zinc terbium oxide thin film transistors with different gallium contents (In: Ga: Zn: Tb = 3: x: 3: 1 (x = 0, 1, 2, 3, 4, 6)) obtained according to the preparation method are shown, the abscissa is the back gate voltage, and the ordinate is the channel current, and the device shows typical n-type transmission characteristics, and the on-off ratio is about 10 6 ; meanwhile, the gallium content significantly affects the transfer characteristic curve of the device.

[0052] Figure 3 is the transfer characteristic curve of 50 devices obtained according to the preparation method, the abscissa is the gallium content of the indium gallium zinc terbium oxide thin film transistor, the ordinate is the threshold voltage (V TH ) and the maximum on-state current (I ON ) obtained, and the error value is the standard deviation. Figure 3 It can be seen that the threshold voltage (V TH ) and the maximum on-state current (I ON ) of the indium gallium zinc terbium oxide thin film transistor with different gallium contents (In: Ga: Zn: Tb = 3: x: 3: 1 (x = 0, 1, 2, 3, 4, 6)) change with the gallium concentration. It can be seen that as the gallium concentration increases, the threshold voltage of the device continuously drifts to the positive direction, and the maximum on-state current continuously decreases, which is mainly due to the fact that gallium has a higher oxygen binding energy, which reduces the concentration of oxygen vacancies, thereby reducing the concentration of carriers in the oxide. Meanwhile, the mobility in the oxide is proportional to the carrier concentration, and the decrease of the final mobility results in a lower on-state current. This embodiment shows that the combination of gallium elements and indium zinc terbium elements can effectively regulate the threshold voltage of the indium gallium zinc terbium oxide thin film transistor.

[0053] Embodiment two

[0054] The preparation method of the indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor provided by the embodiment of the present application has high carrier mobility and good stability, and the threshold voltage can be adjusted, and specifically comprises the following steps:

[0055] Step one, the stabilizer ethanolamine is added to ethylene glycol methyl ether, and the solution is denoted as A0.

[0056] Preferably, the stabilizer ethanolamine is added to ethylene glycol methyl ether at a volume ratio of 0.92%.

[0057] Step two, the corresponding indium nitrate, gallium nitrate, zinc acetate and terbium acetate are added to the solution A0 as precursors in different molar ratios of In: Ga: Zn: Tb, and after stirring for a certain time, a uniform mixed solution is formed for use;

[0058] Preferably, the total molar concentration of all metal cations in the final composite solution is controlled to be 0.03 mol / L.

[0059] Preferably, indium nitrate, gallium nitrate, zinc acetate and terbium acetate with molar ratio of In:Ga:Zn:Tb=3:x:3:1 (x=0, 1, 2, 3, 4, 6) are added into solution A0 as precursors respectively.

[0060] Preferably, the stirring time is 2 hours and the volume of solution A0 is 50ml.

[0061] Step three, carbon nanotubes (CNT) are dissolved in ethylene glycol methyl ether by ultrasonic, and the solution is used as mother liquor after being uniformly suspended by ultrasonic, which is marked as solution A CNT Solution A CNT is added into the above mixed solution, and ultrasonic is continued to make carbon nanotubes uniformly dispersed in the mixed solution, which is marked as B1, B2, B3, B4, B5, B6 respectively.

[0062] Specifically, 50ml of carbon nanotube dispersion A CNT is added into the above solution with molar ratio of In:Zn:Ga:Tb=3:3:x:1 (x=0, 1, 2, 3, 4, 6) at a proportion of 25% of carbon and metal cations in oxides, and ultrasonic is continued for 2 hours to make carbon nanotubes uniformly dispersed in the composite solution, which is marked as B1, B2, B3, B4, B5, B6 respectively.

[0063] Preferably, in the composite thin film, the molar ratio of carbon atoms and metal cations in oxides is 25%, and the molar ratio of gallium is different.

[0064] Step four, solution B1, B2, B3, B4, B5, B6 is spin-coated on a substrate pre-grown with a SiO2 insulating layer respectively, and spin-coating is continued after drying, and the process is repeated until the desired thickness is reached.

[0065] Preferably, the thickness of the SiO2 insulating layer is 100nm.

[0066] Step five, thermal annealing in the atmosphere, and the indium gallium zinc terbium oxide / carbon nanotube composite thin film material is obtained.

[0067] Step six, the composite thin film material is processed to obtain indium gallium zinc terbium oxide / carbon nanotube composite thin film transistors with different gallium (Ga) contents.

[0068] Specifically, by using ultraviolet lithography technology, the composite thin film is etched into independent small pieces by first mask and wet etching, thereby reducing the leakage current; then, after the second mask, the channel length / width is 15μm / 75μm, and the indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor is obtained after metal electrode evaporation and stripping.

[0069] The embodiment provides a preparation method of an indium-gallium-zinc-terbium oxide / carbon nanotube composite thin film transistor.

[0070] Figure 4 The electrical performance curve of the prepared indium-gallium-zinc-terbium oxide / carbon nanotube composite thin film transistor is shown, and the maximum on-state current of the device reaches 0.82mA. Compared with the indium-gallium-zinc-terbium oxide thin film transistor without CNT in the embodiment one, the current is increased by about 20 times under the same voltage. Figure 4 The transconductance (g m ) extracted from (a) is 2.375μS, and the field effect mobility is calculated according to the formula: Wherein, L and W are the channel length and width of the device respectively, C i is the unit capacitance of the gate; after the data is brought in, the mobility of the thin film transistor reaches 130cm 2 / V·s.

[0071] Embodiment three

[0072] The embodiment three of the present application provides a preparation method of a high-stability top-gate indium-gallium-zinc-terbium oxide / carbon nanotube composite thin film transistor, and specifically comprises the following steps.

[0073] Step one, a stabilizer ethanolamine is added into ethylene glycol methyl ether, and the solution is recorded as A0.

[0074] Preferably, the stabilizer ethanolamine is added into ethylene glycol methyl ether at a volume ratio of 0.92%.

[0075] Step two, indium nitrate, gallium nitrate, zinc nitrate and terbium nitrate are added into the solution A0 as precursors respectively at different molar ratios, and after stirring for a certain time, a mixed solution is formed.

[0076] Preferably, the molar ratio of terbium (Tb) to the total amount of indium gallium zinc (In: Ga: Zn = 1: 1: 1) is 1:9.

[0077] Preferably, the total molar concentration of all metal cations in the final composite solution is controlled to be 0.03mol / L, the solution A0 is 50ml, and the stirring time is 2 hours.

[0078] Step three, carbon nanotubes (CNT) are ultrasonically dissolved in ethylene glycol methyl ether, and ultrasonic is used to make them uniformly suspended as a mother liquor for standby, which is recorded as solution A CNT . The solution A CNT is added into the above mixed solution, and ultrasonic is used to form a carbon nanotube uniformly dispersed composite solution D.

[0079] Preferably, 9 mg of carbon nanotubes (CNT) are dissolved in 100 ml of ethylene glycol methyl ether by ultrasonic for 4 h to form a homogeneous suspension as a mother liquor, denoted as solution A. CNT 50 ml of solution A is added to the above mixed solution, and ultrasonic is applied for 2 h to form a carbon nanotube uniformly dispersed composite solution D. CNT 50 ml of solution A is added to the above mixed solution, and ultrasonic is applied for 2 h to form a carbon nanotube uniformly dispersed composite solution D.

[0080] Step four, solution D is spin-coated on a substrate pre-grown with a SiO2 insulating layer, and spin-coating is continued after drying, and the process is repeated until the desired thickness is reached.

[0081] Step five, thermal annealing in air, to obtain an indium gallium zinc terbium oxide / carbon nanotube composite thin film material;

[0082] In the composite thin film, the molar ratio of carbon atoms to metal cations in the oxide is 25%.

[0083] Step six, using ultraviolet lithography technology, through mask, contact electrode evaporation and stripping, a back-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor is obtained.

[0084] Specifically, using ultraviolet lithography technology, through the first mask, the composite thin film is etched into an independent strip with a length of 10 μm and a width of 100 μm by wet etching, increasing the spacing between separate devices and cutting off the possible crosstalk and leakage path between devices; then through the second mask, the channel length / width is 10 μm / 10 μm; using metal thin film deposition process to prepare chromium / gold electrode (10 nm / 50 nm) as contact electrode, after stripping, a back-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor is obtained.

[0085] Step seven, a dielectric layer is prepared, and a top-gate insulating layer is patterned using lithography technology to realize the preparation of a gate electrode, and a top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor is obtained.

[0086] Specifically, a gate window is opened using lithography process, a 15 nm hafnium oxide gate dielectric is prepared using dielectric deposition process, a top-gate insulating layer is patterned using ultraviolet lithography technology, and then a chromium / gold electrode (5 nm / 30 nm) is prepared as a gate contact electrode using metal thin film deposition process, and the metal electrode is completed after stripping, and a top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor is obtained.

[0087] The embodiment provides a preparation method of a top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor. Figure 5(a) shows a cross-sectional schematic diagram of the top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor prepared according to the method, wherein ① is the top gate electrode; ② is the gate insulating layer, which may be silicon nitride, silicon oxide and zirconium oxide, preferably hafnium oxide; ③ is the indium gallium zinc terbium oxide / carbon nanotube composite thin film; ④ and ⑤ together form the substrate, which in this embodiment may be SiO2 / Si and glass; ⑥ is the metal contact electrode, preferably chromium / gold.

[0088] Figures 5-6 The performance curves of the top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin-film transistor prepared according to this method are shown. Figure 5 (b) shows the electrical transfer curve of the thin-film transistor, where the horizontal axis represents the top gate voltage (V). TG The vertical axis represents the channel current (I) of the device. DS The device exhibited excellent n-type transport characteristics, with an on / off ratio reaching 10. 8 It has a low off-state current (10 -14 A) indicates that the top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin-film transistor prepared by this method has good gate control capability.

[0089] Through the Figure 5 (b) shows that the transconductance was extracted to be 0.66 μS, and the mobility of the top-gate transistor was calculated to be 60 cm⁻¹ using the field-effect mobility calculation formula. 2 / V·s.

[0090] Figure 5 (c) shows the output characteristic curve of the top-gate transistor, where the horizontal axis represents the voltage between the source and drain electrodes (V). DS The vertical axis represents the channel current (I) of the device. DS By dividing the measured current by the channel width of the device, the normalized output current of the device reaches 30 mA / μm, a value comparable to that of polysilicon devices of the same size.

[0091] This embodiment verifies that the top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin-film transistor has a high mobility, approaching that of low-temperature polycrystalline silicon.

[0092] Meanwhile, regarding the bias stability of the device, this invention measured the effects of 0%, 5%, and 10% terbium content, corresponding to In:Ga:Zn:Tb ratios of 3:3:3:0, 3:3:3:0.47, and 3:3:3:1, on the high-mobility top-gate indium gallium zinc terbium oxide / carbon nanotube composite thin-film transistor, such as... Figure 6 As shown. Among them, Figure 6(a) is the result of the negative bias illumination stability (NBIS) of the top-gate device, the horizontal axis is the negative gate bias and the light illumination time (wherein the gate bias is -4V, and the light intensity is 250Lux), and the vertical axis is the threshold voltage shift value; Figure 6 (b) is the result of the positive bias illumination stability (PBIS) of the top-gate device, the horizontal axis is the positive gate bias and the light illumination time (wherein the gate bias is -4V, and the light intensity is 250Lux), and the vertical axis is the threshold voltage shift value. The experimental results show that when the molar ratio of Tb to (InGaZn) is 1:9, that is, 10%, the PBIS and NBIS test results of the device show that the threshold voltage drift of the device is less than 1V, and compared with the composite indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor without doping Tb (0%), the device has a significant improvement effect.

[0093] The above examples are only the preferred embodiments of the present application, and cannot limit the implementation and protection scope of the present application. For those skilled in the art, after understanding the content and principles of the present application, the equivalent replacement and modification of the obtained scheme should be included in the protection scope of the present application.

Claims

1. A method for fabricating an indium gallium zinc oxide-based composite thin film transistor, characterized by comprising: The method comprises: ​ Step one, adding stabilizer ethanolamine into ethylene glycol methyl ether, the solution is recorded as A0; Step two, adding indium nitrate, gallium nitrate, zinc nitrate and terbium nitrate into the solution A0 as precursors, after stirring for a certain time, a mixed solution is formed; Step three, carbon nanotubes are dissolved in ethylene glycol methyl ether by ultrasonic, and the solution is used as mother liquor, which is recorded as solution A CNT Solution A is added to the mixed solution, and the carbon nanotubes are dispersed uniformly in the mixed solution by continuous ultrasonic. CNT The dispersion is added to the mixed solution, and the carbon nanotubes are dispersed uniformly in the mixed solution by continuous ultrasonic. Step four, spin coating the solution obtained in step three on a substrate pre-grown with an insulating layer, drying and then continuing spin coating, repeating the process until the desired thickness is reached; Step five, thermal annealing, obtaining indium gallium zinc terbium oxide / carbon nanotube composite film material; In the composite film, the molar ratio of carbon atoms to metal cations in the oxide is 25%; Step six, processing the composite film material to obtain an indium gallium zinc terbium oxide / carbon nanotube composite film transistor; The mobility of the composite thin film transistor device reaches 130 cm 2 / V·s, and the maximum on-state current reaches 0.8 mA.

2. The method of claim 1, wherein: The insulating layer is a SiO2 insulating layer.

3. A top-gate indium gallium zinc oxide-based composite thin film transistor, characterized by: The composite thin film transistor comprises a top gate electrode, a gate insulating layer, an indium gallium zinc terbium oxide / carbon nanotube composite thin film, a substrate and a metal contact electrode, the indium gallium zinc terbium oxide / carbon nanotube composite thin film material is prepared according to the method of claim 1, and the mobility of the top gate indium gallium zinc terbium oxide / carbon nanotube composite thin film transistor reaches 60 cm 2 / V·s.

4. A method for manufacturing a top-gate indium gallium zinc oxide composite thin film transistor, characterized by: The indium gallium zinc terbium oxide / carbon nanotube composite film material is prepared according to the method of claim 1; Using ultraviolet lithography technology, a back gate indium gallium zinc terbium oxide / carbon nanotube composite film transistor is obtained through mask, evaporation and stripping; A dielectric layer is prepared, and a top gate insulating layer is patterned using lithography technology to realize the preparation of a gate electrode, obtaining a top gate indium gallium zinc terbium oxide composite film transistor.

5. The method of claim 4, wherein: The molar ratio of terbium to the total amount of indium gallium zinc is 1:9.

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