Semiconductor oxide film and preparation method therefor

Abstract

The present application provides a semiconductor oxide film and a preparation method therefor. The semiconductor oxide film comprises a plurality of metal oxide layers, and the composition general formula of the plurality of metal oxide layers is AOαBOβROγ, wherein α, β, and γ are respectively cycle numbers of an AO layer, an BO layer, and an RO layer; and AO is a first metal oxide layer, BO is a second metal oxide layer, and RO is a third rare earth metal oxide layer. According to the semiconductor oxide film, by means of regulation and control of components and structures, the second metal oxide layer and the third rare earth metal oxide layer with different effects are introduced at the same time into a metal oxide layer of In and / or Sn, improving the photo-thermal stability of the semiconductor oxide film. The preparation method involves controlling related parameters of an ALD deposition process, and the prepared semiconductor oxide film has extremely high density and uniform component micro-area distribution, is easy to precisely control and has excellent surface morphology coverage.

Description

Semiconductor oxide thin film and preparation method thereof Technical Field

[0001] The present application belongs to the field of semiconductor materials and device technology, and relates to a semiconductor oxide film and a preparation method thereof. Background Art

[0002] The core technology of the emerging flat-panel display industry is thin-film transistor (TFT) backplane technology. Metal oxide TFT (MO-TFT) not only boasts high mobility, but also a relatively simple and versatile manufacturing process, compatibility with existing a-Si processes, low manufacturing costs, and excellent uniformity over large areas. Consequently, MO-TFT technology has garnered significant industry attention since its inception.

[0003] Currently, there are many types of inorganic metal oxide semiconductor materials and preparation methods in use. Commercial semiconductor oxide thin film production methods mainly rely on vacuum sputtering technology (such as physical vapor deposition (PVD)). Although sputtering has the advantage of rapid film formation, it faces many difficulties in raw material formulation and target preparation, such as high-mobility multi-element rare earth doping formula design and large-area target sintering, including: target nodule problems, poor target density, poor target uniformity, etc. Therefore, atomic layer deposition (ALD) is a very promising thin film preparation method that may compete with sputtering processes.

[0004] ALD can achieve good composition control using simple raw materials and can deposit extremely high-quality nanoscale oxide films. In addition, because ALD is an atomic-level deposition process, it has obvious advantages for achieving precise doping of trace elements. The self-limiting deposition mechanism of ALD gives it good three-dimensional conformality, which allows for good thin film deposition on three-dimensional or porous materials. In addition, low-temperature growth (<250°C) is also a major advantage of ALD.

[0005] However, TFT devices currently made of metal oxides have poor thermal stability and photostability. Therefore, developing a semiconductor oxide film with excellent photostability is of extraordinary significance for the industrial application of oxide thin film transistors.

[0006] Summary of the Invention

[0007] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0008] The purpose of this application is to provide a semiconductor oxide thin film and a preparation method thereof, wherein the semiconductor oxide thin film achieves higher mobility while introducing two second metal oxide layers and a third rare earth metal oxide layer with different functions to obtain a semiconductor oxide thin film with excellent photothermal stability, which can be used as an active layer material for thin film transistors.

[0009] To achieve this goal, this application adopts the following technical solutions:

[0010] In a first aspect, the present application provides a semiconductor oxide thin film, wherein the semiconductor oxide thin film comprises multiple metal oxide layers;

[0011] The composition formula of the multi-layer metal oxide layer is AO α BO β RO γ , where α, β, and γ are the number of cycles of AO layer, BO layer, and RO layer, respectively; AO is the oxide layer of the first metal, BO is the oxide layer of the second metal, and RO is the oxide layer of the third rare earth metal.

[0012] The semiconductor oxide film described in this application has an extremely high density, a uniform and easily precisely controlled micro-region distribution of its components, and excellent surface morphology coverage. Furthermore, the semiconductor oxide film is composed of three metal oxide layers made of different materials. Two different second metal oxide layers and a third rare earth metal oxide layer are simultaneously introduced into the metal oxide layers of In and / or Sn, thereby improving the photothermal stability of the semiconductor oxide film.

[0013] It is worth noting that the oxide layer of the first metal in the semiconductor oxide film described in this application is mainly the source of carriers and determines the upper limit of the mobility of the oxide material; the oxide layer of the second metal is mainly used to adjust the microstructure of the oxide film, such as the crystallization state of the material (crystalline and amorphous), and can also inhibit the formation of oxygen vacancies and improve the controllability of the carrier transport process; the oxide layer of the third rare earth metal is mainly used to improve the photothermal stability of the material by rare earth doping. Rare earth elements are doped into the oxide system, which can induce shallow energy level defect states in the oxide system. The defect states can serve as recombination centers for photogenerated carriers and holes, thereby improving the optical bias stability of materials and devices. The main mechanism is that the rare earth elements doped into the oxide substrate can induce shallow energy level "acceptor defects" near the Fermi level, which can act as oxygen vacancies Vo. 2+ It can also be used as a recombination center with electrons, thereby improving the light bias stability problem caused by oxygen vacancies in the device.

[0014] As an optional technical solution of the present application, the first metal includes In and / or Sn.

[0015] In one embodiment, the second metal includes any one or a combination of at least two of Zn, Ga, Ta, W, Bi, Hf, Zr, Ti, Mo or Ge, wherein the combination is typically but not limited to: a combination of Zn and Ga, a combination of Ta and W, a combination of Bi and Hf, or a combination of Zr and Ti, etc.

[0016] In one embodiment, the third rare earth metal includes any one or a combination of at least two of Sc, Y, Ce, Pr, Tb, Dy or Yb, wherein the combination is typically but not limited to: a combination of Sc and Y, a combination of Ce and Pr, a combination of Tb and Dy or a combination of Yb and Dy, etc.

[0017] As an optional technical solution of the present application, the ratio of α and β in the multi-layer metal oxide layer is (1-20):1, for example, it can be 2:1, 4:1, 5:1, 7:1, 9:1, 10:1, 12:1, 14:1, 15:1, 17:1 or 19:1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In one embodiment, the ratio of α to γ ​​in the multi-layer metal oxide layer is (10-100):1, for example, it can be 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1 or 90:1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] It is worth noting that the AO material layer mainly serves as a transport channel layer, and the more layers it has, the higher the mobility. However, as the AO layer increases, the corresponding film is easier to crystallize. Due to the scattering effect of the grain boundary, the mobility will decrease. At the same time, since the AO material itself has a low AO bond energy and there are many defects in the film, the increase of the AO layer will usually also lead to a decline in the photothermal stability of the final device; the present application mainly controls the microstructure of the oxide material system film and then controls the carrier concentration and mobility by regulating the layer ratio of the AO layer and the BO layer in the multilayer metal oxide layer to (1-20):1. And the layer ratio of the AO layer and the RO layer in the multilayer metal oxide layer is regulated to (10-100):1, mainly by adjusting the doping amount of rare earth elements, thereby adjusting the photothermal stability of the device; the lower the layer ratio, the better the stability, but there is also a risk of decreased mobility. Therefore, it is necessary to comprehensively consider the layer ratio relationship of AO / BO / RO to ensure the high mobility, high controllability and high stability of the semiconductor oxide film.

[0020] As an optional technical solution of this application, the thickness of the semiconductor oxide film is For example it could be or etc., but not limited to the listed values. Other values ​​not listed in the numerical range are also applicable and can be selected as

[0021] In one embodiment, the carrier concentration of the semiconductor oxide film is 10 14 -10 21 cm -3 , for example it can be 10 15 cm -3 , 10 16 cm -3 , 10 17 cm -3 , 10 18 cm -3 , 10 19 cm -3 or 10 19 cm -3 etc., but not limited to the listed values. Other values ​​not listed in the numerical range are also applicable. 10 can be selected. 16 -10 20 cm -3 .

[0022] It is worth noting that the carrier concentration determines the upper limit of the mobility of the oxide material. By organically regulating the carrier concentration, a high-mobility TFT device can be obtained. Generally speaking, the higher the carrier concentration, the higher the mobility. This is determined by the carrier transport mechanism of the oxide material system, which is called the percolation threshold theory. However, excessively high carrier concentrations will lead to scattering effects between particles, and there is a risk of decreased mobility. Therefore, this application controls the carrier concentration of the semiconductor oxide film to 10 14 -10 21 cm -3 range, resulting in a higher mobility.

[0023] In this application, it is necessary to strictly and accurately control the element type, film thickness parameters, film microstructure and carrier concentration parameters of the semiconductor oxide film to match, so as to achieve a semiconductor oxide thin film transistor with high mobility and high stability.

[0024] In a second aspect, the present application provides a method for preparing a semiconductor oxide thin film as described in the first aspect, the preparation method comprising:

[0025] Cyclic deposition of AO on substrates using atomic layer deposition α / n BO β / n RO γ / n , to obtain the semiconductor oxide thin film; wherein n is the number of cyclic deposition times.

[0026] In the present application, a sub-cycle of deposition (AO layer+BO layer+RO layer) is first performed, and then n sub-cycles are deposited cyclically to obtain a semiconductor oxide thin film.

[0027] As an optional technical solution of this application, the preparation method specifically includes:

[0028] The substrate is placed in an atomic layer deposition reaction device, and a first metal source precursor, an inert gas and an oxygen source are introduced into the reaction device in sequence to perform α / n-times AO layer deposition; then a second metal source precursor, an inert gas and an oxygen source are introduced into the reaction device in sequence to perform β / n-times BO layer deposition; then a third rare earth metal source precursor, an inert gas and an oxygen source are introduced into the reaction device in sequence to perform γ / n-times RO layer deposition; finally, the semiconductor oxide thin film is obtained through cyclic deposition.

[0029] As an optional technical solution of the present application, the number of cyclic deposition is 10-200, for example, it can be 20, 30, 50, 70, 90, 100, 120, 140, 150, 170 or 190, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In one embodiment, the first metal source precursor includes an In source and / or a Sn source.

[0031] In the present application, the In source includes any one or a combination of at least two of trimethylindium (TMIn), dimethylethylindium (DMEI), cyclopentadienylindium (InCp), [3-(dimethylamino)propyl]dimethylindium (DADI) or (N,N-dimethylbutylamine)trimethylindium (DATI).

[0032] In the present application, the Sn source includes any one of SnCl4, tetrakis(dimethylamine)tin (TDMASn) or bis(N,N'-di-iso-propylacetamidine)tin(II)Sn(iPr-MeAMD)2 or a combination of at least two thereof.

[0033] In one embodiment, the pulse time of the first metal source precursor is 0.03-2s, for example, it can be 0.05s, 0.07s, 0.1s, 0.3s, 0.5s, 0.7s, 0.9s, 1s, 1.1s, 1.3s, 1.5s, 1.7s or 1.9s, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In one embodiment, the flow rate of the first metal source precursor is 10-500sccm, for example, it can be 30sccm, 50sccm, 70sccm, 100sccm, 150sccm, 200sccm, 250sccm, 300sccm, 350sccm, 400sccm or 450sccm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In one embodiment, the chemical source temperature of the first metal source precursor is 50-130°C, for example, it can be 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] In one embodiment, the thin film deposition temperature of the first metal source precursor is 150-300°C, for example, it can be 160°C, 170°C, 200°C, 220°C, 240°C, 250°C, 270°C or 290°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In one embodiment, the plasma power for depositing the AO layer is 50-300 W, for example, 60 W, 70 W, 90 W, 100 W, 120 W, 150 W, 170 W, 200 W, 220 W, 250 W, 270 W or 290 W, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] As an optional technical solution of the present application, the second metal source precursor includes any one of Zn source, Ga source, Ta source, W source, Bi source, Hf source, Zr source, Ti source, Mo source or Ge source, or a combination of at least two of them.

[0039] In the present application, the Zn source includes diethylzinc (DEZ); the Ga source includes trimethylgallium (TMGa) and / or triethylgallium (TEGa); the Ta source includes any one of tert-butylamine tris(diethylamine) tantalum (TBTDEAT), tert-butylamine tris(ethylmethylamine) tantalum (TBTEMAT) or penta(dimethylamine) tantalum (PDMAT) or a combination of at least two thereof; the W source includes di-tert-butylamine bis(dimethylamine) tungsten (BTBMW) and / or WF6; the Bi source includes bismuth heptanedione (Bi(thd)2); the Hf source includes tetra(dimethylamine) hafnium (TDMAHf), Any one of tetrakis(ethylmethylamino)hafnium (TEMAHf) or cyclopentadienylhafnium (CpHf), or a combination of at least two thereof; the Zr source includes any one of tetrakis(dimethylamino)zirconium (TDMAZr), tetrakis(ethylmethylamino)zirconium (TEMAZr), or cyclopentadienylzirconium (CpZr), or a combination of at least two thereof; the Ti source includes any one of TiCl4, tetrakis(ethylmethylamino)titanium (TDMATi), or titanium tetraisopropoxide (TTIP), or a combination of at least two thereof; the Mo source includes bis(tert-butylimino)bis(dimethylamino)molybdenum(VI); and the Ge source includes tetrakis(dimethylamino)germanium.

[0040] In one embodiment, the pulse time of the second metal source precursor is 0.01-1.5s, for example, it can be 0.03s, 0.05s, 0.07s, 0.1s, 0.3s, 0.5s, 0.7s, 0.9s, 1s, 1.1s, 1.3s or 1.4s, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] In one embodiment, the inlet flow rate of the second metal source precursor is 20-300sccm, for example, it can be 30sccm, 50sccm, 70sccm, 90sccm, 100sccm, 120sccm, 150sccm, 170sccm, 200sccm, 220sccm, 250sccm, 270sccm or 290sccm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] In one embodiment, the chemical source temperature of the second metal source precursor is 20-100°C, for example, it can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C or 90°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In one embodiment, the thin film deposition temperature of the second metal source precursor is 150-300°C, for example, it can be 160°C, 170°C, 200°C, 220°C, 240°C, 250°C, 270°C or 290°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] In one embodiment, the plasma power for depositing the BO layer is 50-200 W, for example, 60 W, 70 W, 80 W, 100 W, 120 W, 140 W, 150 W, 170 W or 190 W, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] As a preferred technical solution of the present application, the third rare earth metal source precursor includes any one of Sc source, Y source, Ce source, Pr source, Tb source, Dy source or Yb source, or a combination of at least two thereof.

[0046] In the present application, the Sc source includes tris(2,2,6,6-tetramethyl-3,5-heptanedione)scandium Sc(thd)3; the Y source includes tris(2,2,6,6-tetramethyl-3,5-heptanedione)yttrium Y(thd)3 and / or tris(cyclopentadienyl)yttrium (MeCp)3Y; the Ce source includes tetra(2,2,6,6-tetramethyl-3,5-heptanedione)cerium Ce(thd)4; the Pr source includes tris(2,2,6,6-tetramethyl-3,5-heptanedione)praseodymium Pr(thd)3 and / or triisopropylcyclopentadienylpraseodymium ( The invention relates to a novel ytterbium ore (Yb) source, wherein the ytterbium ore (Yb) source comprises tris(2,2,6,6-tetramethyl-3,5-heptanedione) terbium Tb(thd)3 and / or triisopropylcyclopentadienyl terbium (iPCp)3Tb; the ytterbium ore (Yb) source comprises tris(2,2,6,6-tetramethyl-3,5-heptanedione) dysprosium Dy(thd)3 and / or triisopropylcyclopentadienyl dysprosium (iPCp)3Dy; the ytterbium ore (Yb) source comprises tris(2,2,6,6-tetramethyl-3,5-heptanedione) ytterbium Yb(thd)3 and / or triisopropylcyclopentadienyl ytterbium (iPCp)3Yb.

[0047] In one embodiment, the pulse time of the third rare earth metal source precursor is 0.05-3s, for example, it can be 0.07s, 0.1s, 0.3s, 0.5s, 0.7s, 0.9s, 1s, 1.1s, 1.3s, 1.5s, 1.7s, 2s, 2.1s, 2.3s, 2.5s, 2.7s or 2.9s, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] In one embodiment, the flow rate of the third rare earth metal source precursor is 50-500sccm, for example, it can be 100sccm, 150sccm, 200sccm, 250sccm, 300sccm, 350sccm, 400sccm or 450sccm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] In one embodiment, the chemical source temperature of the third rare earth metal source precursor is 60-150°C, for example, it can be 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or 140°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In one embodiment, the thin film deposition temperature of the third rare earth metal source precursor is 150-300°C, for example, it can be 160°C, 170°C, 200°C, 220°C, 240°C, 250°C, 270°C or 290°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] In one embodiment, the plasma power for depositing the RO layer is 100-500W, for example, 150W, 200W, 250W, 300W, 350W, 400W or 450W, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] As an optional technical solution of the present application, the purge time of the inert gas is 5-30s, for example, it can be 7s, 9s, 10s, 12s, 15s, 17s, 19s, 20s, 22s, 25s, 27s or 29s, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] In the present application, the inert gas includes nitrogen.

[0054] In one embodiment, the oxygen source includes any one of O2, H2O, H2O2, O3 or oxygen plasma, or a combination of at least two thereof, wherein the combination is typically but not limited to: a combination of O2 and H2O, a combination of H2O and H2O2, or a combination of oxygen plasma and O3, etc.

[0055] In one embodiment, the pulse time of the oxygen source is 0.2-50 s, for example, 0.5 s, 1 s, 3 s, 5 s, 7 s, 9 s, 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s or 45 s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0056] In the present application, when depositing different metal oxide layers, the flow rate and pulse time of the oxygen source are different and are not specifically limited here, as long as the introduced oxygen source reacts with the metal source precursor to generate the corresponding metal oxide molecular layer.

[0057] The numerical range described in this application includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to limited space and for the sake of simplicity, this application no longer exhaustively lists the specific point values ​​included in the range.

[0058] Compared with the prior art, this application has the following beneficial effects:

[0059] (1) The semiconductor oxide film provided by the present application is composed of three metal oxide layers of different materials at the atomic layer thickness level through the regulation of composition and structure. In the metal oxide layer of In and / or Sn, two second metal oxide layers with different functions and a third rare earth metal oxide layer are simultaneously introduced, thereby improving the light and heat stability of the semiconductor oxide film;

[0060] (2) The preparation method provided in this application controls the relevant parameters of the ALD deposition process, so that the semiconductor oxide film obtained has extremely high density, uniform and easy to accurately control the distribution of components in micro-regions, and excellent surface morphology coverage.

[0061] Still other aspects will become apparent upon reading and understanding the detailed description. DETAILED DESCRIPTION

[0062] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0063] The semiconductor oxide films prepared in the following examples and comparative examples were tested for thickness and carrier concentration. The semiconductor oxide films were deposited on Si wafer substrates and the thickness was tested using an ellipsometer; the semiconductor oxide films were deposited on glass substrates with a thickness of The semiconductor oxide film is tested using a Hall tester to measure the carrier concentration of the film.

[0064] Semiconductor oxide films prepared in the following examples and comparative examples were fabricated into TFT devices and subjected to a light-to-heat stability (NBITS) test. The threshold voltage (Vth) drift (ΔVth) of the TFT devices was measured under negative gate bias (Vgs = -30V), exposure to heat (60°C) and illumination (15,000 nits).

[0065] The manufacturing process of TFT device includes the following steps:

[0066] (1) Depositing a buffer layer SiO2 on a glass substrate;

[0067] (2) ALD preparation of oxide active layer thin film material; patterning etching; and annealing treatment;

[0068] (3) Depositing an insulating layer SiO2 and a metal gate Mo; performing patterning and self-aligned dry etching to form an SD contact area;

[0069] (4) depositing an interlayer insulating layer SiO2; performing patterned etching;

[0070] (5) Depositing source / drain electrodes S / D; performing patterned etching;

[0071] (6) Deposit a protective layer of SiO2; perform graphic etching.

[0072] Example 1

[0073] This embodiment provides a semiconductor oxide film and a preparation method thereof, wherein the semiconductor oxide film comprises a plurality of metal oxide layers; the composition formula of the plurality of metal oxide layers is (In2O3) 300 (ZnO) 30 (Sc2O3) 10 ;

[0074] The method for preparing the semiconductor oxide thin film comprises the following steps:

[0075] (1) The substrate was placed in an atomic layer deposition reactor, and a TMIn pulse was introduced into the reactor at a flow rate of 240 sccm for 1 s. Then, nitrogen was introduced for 20 s to remove excess TMIn from the chamber. Then, an oxygen plasma pulse was introduced at a flow rate of 240 sccm for 20 s, and 30 In2O3 layer depositions were performed.

[0076] The temperature of the chemical source for introducing TMIn is 50°C; the temperature for depositing the In2O3 layer is 200°C and the plasma power is 230W;

[0077] (2) After the oxygen plasma pulse in step (1) is completed, a DEZ pulse is introduced into the reaction device at a flow rate of 150 sccm for 0.8 s, and then nitrogen is introduced for 20 s to remove excess DEZ from the cavity. Thereafter, an oxygen plasma pulse is introduced at a flow rate of 100 sccm for 10 s, and ZnO layer deposition is performed three times;

[0078] The temperature of the chemical source introduced into the DEZ is 25°C; the temperature of the ZnO layer deposition is 200°C and the plasma power is 120W;

[0079] (3) After the oxygen plasma pulse in step (2) is completed, a Sc(thd)3 pulse is introduced into the reaction device at a flow rate of 240 sccm for 1.5 seconds, and then nitrogen is introduced for 20 seconds to remove excess Sc(thd)3 from the cavity. Thereafter, an oxygen plasma pulse is introduced at a flow rate of 240 sccm for 30 seconds to perform one Sc2O3 layer deposition;

[0080] The temperature of the chemical source for introducing Sc(thd)3 is 100°C; the temperature for depositing the Sc2O3 layer is 200°C and the plasma power is 300W;

[0081] (4) The operation from step (1) to step (3) is regarded as a large cycle, and the large cycle is repeated 10 times to obtain the semiconductor oxide thin film.

[0082] Example 2-11

[0083] The types of metal oxides in each layer and the chemical source temperature parameters of the precursor were changed, as shown in Table 1. Other conditions were the same as in Example 1. The film performance test results are shown in Table 1.

[0084] Table 1

[0085] As can be seen from Table 1: The semiconductor oxide thin film and its preparation method provided in this application, while achieving a higher mobility, is obtained by introducing two second metal oxide layers and a third rare earth metal oxide layer with different functions and controlling the carrier concentration to obtain a semiconductor oxide thin film with excellent photothermal stability, which can be used as an active layer material for thin film transistors.

[0086] Examples 12-14

[0087] The layer ratio parameters of the AO / BO layer and the AO / RO layer were changed as shown in Table 2. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 2.

[0088] Table 2

[0089] It can be seen from Table 2 that: when the layer ratio of the AO layer and the BO layer is too small, the content of the AO layer (In or Sn) as the main source of carriers is relatively reduced, which makes the growth rate of the obtained semiconductor oxide thin film significantly increased, resulting in a decrease in the carrier concentration of the film and improved photothermal stability; when the layer ratio of the AO layer and the BO layer is too large, the content of the AO layer (In or Sn) as the main source of carriers is relatively increased, which makes the growth rate of the obtained semiconductor oxide thin film slightly decreased. At the same time, due to the increase in the carrier concentration of the film, the photothermal stability deteriorates significantly; when the layer ratio of the AO layer and the RO layer is too small, the content of the RO layer as a carrier inhibitor is relatively increased, which makes the growth rate of the obtained semiconductor oxide thin film slightly increased, resulting in a decrease in the carrier concentration of the film and improved photothermal stability.

[0090] Examples 15-16

[0091] The chemical source temperature parameters of the first metal source precursor were changed as shown in Table 3. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 3.

[0092] Table 3

[0093] It can be seen from Table 3 that: when the chemical source temperature of the first metal source precursor is too low, the precursor cannot effectively enter the chamber for adsorption-reaction due to the low vapor pressure temperature of the precursor, which causes the growth rate of the obtained semiconductor oxide film to drop significantly, and the film thickness decreases, but the carrier concentration and photothermal stability are not much different; when the chemical source of the first metal source precursor is too high, because the vapor pressure of the precursor has reached the saturated vapor pressure of the material itself, the growth rate of the obtained semiconductor oxide film does not change much, and the carrier concentration and photothermal stability are also not much different, but the production cost is increased.

[0094] Examples 17-19

[0095] The plasma power parameters for AO layer deposition were changed as shown in Table 4. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 4.

[0096] Table 4

[0097] Table 4 shows that when the AO layer deposition power is too low, the low plasma power density reduces the precursor reaction activity during film growth, resulting in incomplete precursor site reaction, significantly reducing the growth rate of the resulting semiconductor oxide film, significantly reducing the carrier concentration of the film, and not significantly changing the photothermal stability. When the AO layer deposition power is too high, the high plasma power density reduces the precursor reaction activity during film growth, resulting in complete precursor site reaction, significantly increasing the growth rate of the resulting semiconductor oxide film, with no significant change in the carrier concentration of the film. However, due to the increased AO layer content, the photothermal stability is significantly degraded. Furthermore, as the AO layer deposition power continues to increase, the plasma self-etching effect, i.e., film growth and film etching, occurs simultaneously, makes the film etching effect more pronounced due to excessive power, resulting in a slight decrease in film thickness.

[0098] Example 20

[0099] This embodiment provides a semiconductor oxide film and a preparation method thereof, wherein the semiconductor oxide film comprises a plurality of metal oxide layers; the composition formula of the plurality of metal oxide layers is (In2O3) 300 (TiO2) 30 (Sc2O3) 10 ;

[0100] The method for preparing the semiconductor oxide thin film is the same as that in Example 1, except that step (2) is adjusted as follows: after the oxygen plasma pulse in step (1) ends, a TDMATi pulse is introduced into the reaction device at a flow rate of 150 sccm for 0.3 s, and then nitrogen is introduced for 15 s to purge excess TDMATi material out of the cavity, and then an oxygen plasma pulse is introduced at a flow rate of 150 sccm for 15 s to perform three TDMATi layer depositions. Other conditions are the same as those in Example 1.

[0101] Examples 21-23

[0102] The layer ratio parameters of the AO / BO layer were changed as shown in Table 5. Other conditions were the same as those in Example 20. The film performance test results are shown in Table 5.

[0103] Table 5

[0104] It can be seen from Table 5 that: when the layer ratio of the AO layer and the BO layer is too large, the content of the BO layer, which is the main source of carrier inhibitors, is relatively reduced, so that the growth rate of the obtained semiconductor oxide thin film decreases slightly. At the same time, the carrier concentration of the film increases, but the photothermal stability deteriorates seriously; when the layer ratio of the AO layer and the BO layer is too small, the content of the BO layer, which is the main source of carrier inhibitors, is relatively increased, so that the growth rate of the obtained semiconductor oxide thin film increases slightly, but the carrier concentration of the film decreases, and the photothermal stability is significantly improved; when the BO layer content is further increased (AO / BO=300 / 150), the BO layer itself crystallizes and it is difficult to play the role of carrier suppression of the AO layer, and the photothermal stability will deteriorate to a certain extent.

[0105] Examples 24-25

[0106] The plasma power parameters for BO layer deposition were changed as shown in Table 6. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 6.

[0107] Table 6

[0108] It can be seen from Table 6 that when the power of BO layer deposition is too low, the plasma power density is low, which leads to a decrease in the reaction activity of the precursor for film growth and incomplete site reaction of the precursor, resulting in a significant decrease in the growth rate of the obtained semiconductor oxide film. In addition, the content of the BO layer as a carrier inhibitor is reduced, the carrier concentration of the film will increase, and there is a risk of deterioration in the photothermal stability. When the power of BO layer deposition is too high, although the plasma power density is high, the site reaction of the precursor is basically complete, resulting in less obvious changes in the film growth rate, the carrier concentration of the film, and the photothermal stability.

[0109] Examples 26-27

[0110] The chemical source temperature parameters of the third rare earth metal source precursor were changed as shown in Table 7. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 7.

[0111] Table 7

[0112] It can be seen from Table 7 that: when the chemical source temperature of the third metal source precursor is too low, the precursor cannot effectively enter the chamber for adsorption-reaction due to the low vapor pressure temperature of the precursor, which causes the RO layer content of the obtained semiconductor oxide film to decrease significantly, the carrier concentration to increase, but the photothermal stability to deteriorate significantly; when the chemical source temperature of the third metal source precursor is too high, the vapor pressure of the precursor has reached the saturated vapor pressure of the material itself, so the growth rate of the obtained semiconductor oxide film does not change much, but the RO layer can be fully bonded with the AO layer, resulting in a decrease in the carrier concentration and a significant improvement in the photothermal stability.

[0113] Examples 28-29

[0114] The plasma power parameters for RO layer deposition were changed as shown in Table 8. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 8.

[0115] Table 8

[0116] It can be seen from Table 8 that: when the power of RO layer deposition is too low, due to the low power density of plasma, the reaction activity of the precursor for film growth is reduced, and the site reaction of the precursor is incomplete, so that the RO layer content of the prepared semiconductor oxide film is significantly reduced, and the carrier concentration is significantly reduced, resulting in a significant deterioration of the photothermal stability; when the power of RO layer deposition is too high, although the power density of plasma is high, the site reaction of the precursor is basically complete, resulting in less obvious changes in the film growth rate, the carrier concentration of the film, and the photothermal stability.

[0117] Comparative Examples 1-3

[0118] The composition parameters of the semiconductor oxide film were changed as shown in Table 9. Other conditions were the same as those in Example 1. The film performance test results are shown in Table 9.

[0119] Table 9

[0120] It can be seen from Table 9 that: when the BO layer is not deposited, due to the lack of carrier inhibitors and thin film growth crystal form controllers, the carrier concentration of the obtained semiconductor oxide thin film is relatively high, the TFT device is difficult to control the switching performance, and the photothermal stability is significantly deteriorated; when the RO layer is not deposited, due to the lack of passivation and suppression of oxygen vacancy defects in the film, the carrier concentration of the obtained semiconductor oxide thin film is relatively high, the TFT device is difficult to control the switching performance, and the photothermal stability is significantly deteriorated; when the semiconductor oxide thin film is a single-layer metal oxide layer, that is, all metal oxides are mixed and deposited, because each layer of material cannot use its own sites to react with the oxidant for oxidation, the growth rate of the film is significantly reduced, which reduces the carrier concentration of the obtained semiconductor oxide thin film (especially the AO layer). At the same time, since the BO / RO layers fail to effectively form films and bonds, the photothermal stability will be significantly reduced.

Claims

1. A semiconductor oxide thin film comprising multiple metal oxide layers; The composition formula of the multi-layer metal oxide layer is AO α BO β RO γ , where α, β, and γ are the number of cycles of AO layer, BO layer, and RO layer, respectively; AO is the oxide layer of the first metal, BO is the oxide layer of the second metal, and RO is the oxide layer of the third rare earth metal.

2. The semiconductor oxide thin film according to claim 1, wherein The first metal includes In and / or Sn; Optionally, the second metal includes any one or a combination of at least two of Zn, Ga, Ta, W, Bi, Hf, Zr, Ti, Mo or Ge; Optionally, the third rare earth metal includes any one or a combination of at least two of Sc, Y, Ce, Pr, Tb, Dy or Yb.

3. The semiconductor oxide thin film according to claim 1 or 2, wherein The ratio of α to β in the multi-layer metal oxide layer is (1-20):1; Optionally, the ratio of α to γ ​​in the multi-layer metal oxide layer is (10-100):

1.

4. The semiconductor oxide thin film according to any one of claims 1 to 3, wherein The thickness of the semiconductor oxide film is Further optional Optionally, the carrier concentration of the semiconductor oxide film is 10 14 -10 21 cm -3 , further optional to 10 16 -10 20 cm -3 .

5. A method for preparing a semiconductor oxide thin film according to any one of claims 1 to 4, comprising: Cyclic deposition of AO on substrates using atomic layer deposition α / n BO β / n RO γ / n , to obtain the semiconductor oxide thin film; wherein n is the number of cyclic deposition times.

6. The preparation method according to claim 5, wherein The preparation method specifically comprises: The substrate is placed in an atomic layer deposition reaction device, and the first metal source precursor, inert gas and oxygen source are introduced into the reaction device in sequence to perform α / n times AO layer deposition; then the second metal source precursor, inert gas and oxygen source are introduced into the reaction device in sequence. Two metal source precursors, an inert gas and an oxygen source are used to deposit a β / n-time BO layer; then a third rare earth metal source precursor, an inert gas and an oxygen source are introduced into the reaction device in sequence to deposit a γ / n-time RO layer; finally, the semiconductor oxide film is obtained through cyclic deposition.

7. The preparation method according to claim 6, wherein The number of cyclic deposition is 10-200; Optionally, the first metal source precursor includes an In source and / or a Sn source; Optionally, the pulse time of the first metal source precursor is 0.03-2s; Optionally, the flow rate of the first metal source precursor is 10-500 sccm; Optionally, the chemical source temperature of the first metal source precursor is 50-130°C; Optionally, the AO layer is deposited at a temperature of 150-300°C; Optionally, the plasma power for depositing the AO layer is 50-300W.

8. The preparation method according to claim 6 or 7, wherein The second metal source precursor includes any one of a Zn source, a Ga source, a Ta source, a W source, a Bi source, a Hf source, a Zr source, a Ti source, a Mo source or a Ge source, or a combination of at least two thereof; Optionally, the pulse time of the second metal source precursor is 0.01-1.5s; Optionally, the flow rate of the second metal source precursor is 20-300 sccm; Optionally, the chemical source temperature of the second metal source precursor is 25-100°C; Optionally, the thin film deposition temperature of the second metal source precursor is 150-300°C; Optionally, the plasma power for depositing the BO layer is 50-200W.

9. The preparation method according to any one of claims 6 to 8, wherein The third rare earth metal source precursor includes any one of Sc source, Y source, Ce source, Pr source, Tb source, Dy source or Yb source, or a combination of at least two thereof; Optionally, the pulse time of the third rare earth metal source precursor is 0.05-3s; Optionally, the flow rate of the third rare earth metal source precursor is 50-500 sccm; Optionally, the chemical source temperature of the third rare earth metal source precursor is 60-150° C.; Optionally, the thin film deposition temperature of the third rare earth metal source precursor is 150-300° C.; Optionally, the plasma power for depositing the RO layer is 100-500W.

10. The preparation method according to any one of claims 6 to 9, wherein: The purge time of the inert gas is 5-30s; Optionally, the oxygen source includes any one of O2, H2O, H2O2, O3 or oxygen plasma, or a combination of at least two thereof; Optionally, the pulse time of the oxygen source is 0.2-50s.