Metal oxide semiconductors and thin film transistors and their applications

Abstract

The present invention discloses a metal oxide semiconductor, which is obtained by doping an indium-containing metal oxide with at least two rare earth elements R and R', respectively, to form an In x M y R n R' m O z The present invention utilizes the extremely high oxygen debonding energy in the oxides of rare earth elements R to effectively control the carrier concentration in the semiconductor, and utilizes the property that the radius of rare earth ions corresponds to the radius of indium ions to form charge conversion centers and improve their electrical stability. The present invention also provides thin film transistors based on this metal oxide semiconductor and their applications.

Description

[Technical field]

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to materials and device structures used in the fabrication of metal oxide semiconductor thin film transistor backplanes in flat panel display and detector applications, and more particularly to metal oxide semiconductors and thin film transistors and applications. [Background technology]

[0002] In conventional metal oxide semiconductor systems, indium ions (In 3+ ) has a relatively large ionic radius, so that the orbitals overlap with a higher probability in polyvalent metal oxides, ensuring an efficient carrier transport path, and the 5s orbital is the main electron transport path. However, on the one hand, indium has a low In-O bond dissociation energy after bonding with oxygen, so there are many oxygen vacancies in simple indium oxide (In2O3) thin films. The oxygen vacancies are a factor that deteriorates the stability of metal oxide thin film transistors. On the other hand, there is a lot of lattice mismatch in conventional sputter-deposited indium oxide, which results in low carrier mobility in the thin film, limiting its application to high-performance thin film transistors. In general, the number of In 3+ Ga equivalent to ions 3+ Ion doping is required to control the oxygen vacancies, while the metal oxide semiconductor thin film must maintain an amorphous thin film structure to ensure the uniformity of the semiconductor device performance.

[0003] Since the crystal structure of ZnO is significantly different from that of the two materials In2O3 and Ga2O3, doping the thin film with Zn ions equivalent in number to the number of In ions can suppress the crystallization of the material and maintain the amorphous structure of the thin film. Therefore, among the current metal oxide semiconductor materials, IGZO (In:Ga:Zn = 1:1:1 mol) is the most widely used.

[0004] However, IGZO has some problems. 3+ and Zn2+ Since more ions are added, In 3+ The concentration of was greatly diluted, further reducing the degree of overlap of the 5s orbitals and decreasing the electron mobility.

[0005] In addition, materials such as IGZO have many trap states near the valence band, which means that even when the light irradiation energy is smaller than the forbidden band, photocarriers are generated, which causes the problem of poor light stability in current metal oxide semiconductors. Summary of the Invention [Problem to be solved by the invention]

[0006] In order to overcome the deficiencies of the prior art, the present invention provides a metal oxide semiconductor with relatively high mobility and strong photostability, which is a new co-doping strategy that utilizes the characteristics of the special 4f electron orbitals of rare earth oxides to realize high mobility in a high In ratio oxide thin film, while controlling the carrier concentration and obtaining a metal oxide semiconductor with strong photostability. [Means for solving the problem]

[0007] The novel co-doping strategy of the present invention is to simultaneously introduce two different roles of rare earth element R oxide material and rare earth element R' oxide material into indium-containing metal oxide, where the rare earth element R oxide is a carrier concentration control agent, and the rare earth element R' oxide is a light stabilizer, that is, the rare earth element R' oxide is a charge conversion center, and the action principle is as follows:

[0008] The carrier concentration control agent is Yb in ytterbium oxide and europium oxide, which are oxides of rare earth elements R. 2+ Ion and Eu 2+ The ions have a fully filled 4f orbital and a half filled 4f orbital, respectively. Therefore, divalent ions in the oxide of rare earth element R have a lower energy in the oxide than trivalent ions. In oxide semiconductors, In3+ When doping is performed to replace the ions, the carrier concentration can be obviously reduced. At the same time, the bond breaking enthalpy (ΔHf298) of Yb-O and Eu-O is 715.1 kJ / mol and 557.0 kJ / mol, respectively, which is much larger than the bond breaking energy of In-O (360.0 kJ / mol), allowing for effective control of the oxygen vacancy concentration. In summary, by combining the above two features, the introduction of rare earth element R oxide can effectively control the oxygen vacancies in oxide semiconductor thin films in high In systems, where Yb 2+ The ionic radius of Eu 2+ Since the In-In distance in the oxide semiconductor is smaller than that of the In-In semiconductor, the In-In distance can be reduced, and the high mobility characteristic can be maintained. The light stabilizer utilizes the property that the rare earth ion radius of materials such as praseodymium oxide, terbium oxide, cerium oxide, and dysprosium oxide, which are oxides of a rare earth element R', corresponds to the indium ion radius of indium oxide, and that the electronic structure of the 4f orbital in a rare earth ion and the 5s orbital of an indium ion can form an effective charge conversion center, to improve the electrical stability, particularly the stability under light irradiation.

[0009] A second object of the present invention is to provide a thin film transistor including this metal oxide semiconductor.

[0010] A third object of the present invention is to provide applications of this thin film transistor.

[0011] The present invention is realized by the following technical solutions.

[0012] A metal oxide semiconductor, which is a metal oxide semiconductor, is formed by doping an indium-containing metal oxide MO-In2O3 semiconductor with at least two oxides of rare earth elements R and R', respectively, to form a metal oxide semiconductor having an indium-containing oxide MO-In2O3 semiconductor. x M y R n R' m O zA semiconductor material has been formed, where x+y+m+n=1, 0.4≦x<0.9999, 0≦y<0.5, 0.0001≦(m+n)≦0.2, m>0, n>0, and z>0.

[0013] That is, the metal oxide semiconductor according to the present invention is a compound semiconductor based on indium oxide, and two kinds of rare earth oxides with different functions and complementary actions are introduced by means of co-doping. Here, the selective materials of the oxide of rare earth element R are ytterbium oxide and europium oxide, which is because the Yb oxide in ytterbium oxide and europium oxide as a carrier concentration control agent is used. 2+ Ion and Eu 2+ The ions have a fully filled 4f orbital and a half filled 4f orbital, respectively. Therefore, divalent ions in the oxide of rare earth element R have a lower energy in the oxide than trivalent ions. In oxide semiconductors, In 3+ When doping is performed to replace the ions, the carrier concentration can be obviously reduced. At the same time, the bond breaking enthalpy (ΔHf298) of Yb-O and Eu-O is 715.1 kJ / mol and 557.0 kJ / mol, respectively, which is much larger than the bond breaking energy of In-O (360.0 kJ / mol), allowing for effective control of the oxygen vacancy concentration. Combining the above two features, the introduction of the oxide of rare earth element R can effectively control the oxygen vacancies in oxide semiconductor thin films in high In systems. Here, Yb 2+ The ionic radius of Eu 2+ Since the In-In distance in the oxide semiconductor is smaller than that of the In-In semiconductor, the In-In distance can be reduced, and the high mobility characteristic can be maintained.

[0014] At the same time, the selective materials of oxides of rare earth element R' are praseodymium oxide, terbium oxide, cerium oxide, and dysprosium oxide. This material utilizes the electronic structure characteristics of the 4f orbital in rare earth ions, which can form an effective charge conversion center with the 5s orbital of indium ions. Under forward bias, the rare earth ions are in a stable low-energy state, and the carrier concentration in the thin film is high due to the modulation of the Fermi level, which can effectively shield the carrier scattering effect caused by this conversion center, and thus does not significantly affect the electrical characteristics of the device. Under negative bias, the electron orbital in the rare earth element 4f combines with the 5s orbital of indium, and the rare earth ions enter an unstable activated state. On the one hand, it increases the off-current of the device and enhances the carrier scattering effect, slightly increasing the subthreshold swing value of the device; on the other hand, when suitable light is generated and photocarriers are generated, the photocarriers are quickly "trapped" by the activated conversion center, and the photocarriers and ionized oxygen vacancies are recombined by the bonding orbital in the form of non-radiative transition, and the activated center returns to the activated state again. Therefore, the conversion center provides a fast recombination path for the photocarriers, and the influence on the IV characteristics and stability can be avoided. The stability of the metal oxide semiconductor device under light irradiation is greatly improved.

[0015] Furthermore, the oxide of the rare earth element R is a carrier concentration control agent, and the oxide of the rare earth element R is one or a combination of two materials selected from the group consisting of ytterbium oxide and europium oxide.

[0016] Furthermore, the oxide of the rare earth element R' is a light stabilizer, and the oxide of the rare earth element R' is one of praseodymium oxide, terbium oxide, cerium oxide, and dysprosium oxide, or a combination of any two or more of these materials.

[0017] Furthermore, in the MO, M is one of Zn, Ga, Sn, Ge, Sb, Al, Mg, Ti, Zr, Hf, Ta, and W, or a combination of any two or more of these materials.

[0018] Furthermore, the metal oxide semiconductor is manufactured and deposited by a method employing any one of a physical vapor deposition process, a chemical vapor deposition process, an atomic layer deposition process, a laser deposition process, a reactive ion deposition process, and a solution deposition process.

[0019] The second object of the present invention is achieved by the following technical solution.

[0020] A thin film transistor including a gate electrode, an active layer, an insulating layer located between the gate electrode and the active layer, a source electrode and a drain electrode electrically connected to both ends of the active layer, respectively, and a spacer layer, wherein the active layer is the metal oxide semiconductor described above.

[0021] That is, the present invention further provides a thin film transistor formed by an active layer manufactured based on this metal oxide semiconductor, in which an oxide material of a rare earth element R and an oxide of a rare earth element R' having two different roles are simultaneously introduced into a metal oxide containing indium, in which the oxide of the rare earth element R is a carrier concentration control agent and the oxide of the rare earth element R' is a light stabilizer, thereby maintaining a relatively high mobility property and improving its electrical stability, especially the stability under light irradiation.

[0022] Furthermore, the spacer layer may be a single layer or a laminate of two or more of silicon oxide, silicon nitride, and silicon oxynitride thin films manufactured by plasma enhanced chemical vapor deposition.

[0023] The third object of the present invention is achieved by the following technical solution.

[0024] The application of the thin film transistor to a display panel or a detector. Effect of the Invention

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The present invention uses a novel co-doping strategy to introduce two functionally different rare earth oxide materials into an indium-based metal oxide to realize carrier concentration control and achieve good device photostability effect, providing a novel idea for the realization of future high-performance metal oxide semiconductor materials.

[0027] The present invention forms a metal oxide semiconductor by introducing at least two oxides of rare earth element R and rare earth element R' into a metal oxide containing indium, using the oxide of rare earth element R as a carrier concentration control agent and the oxide of rare earth element R' for enhancing light stability, with the aim of more effectively controlling the carrier concentration in the oxide semiconductor by utilizing the extremely high oxygen bond release energy in the oxide of rare earth element R. At the same time, the electrical stability, particularly stability under light irradiation, is improved by utilizing the characteristic that the rare earth ion radius corresponds to the indium ion radius in indium oxide, and the electronic structure of the 4f orbital in the rare earth element R' ion and the 5s orbital of the indium ion can form an effective charge conversion center. [Brief description of the drawings]

[0028] [Figure 1] FIG. 11 is a structural schematic diagram of the thin film transistors of Examples 13 and 14. [Diagram 2] FIG. 1 is a structural schematic diagram of the thin film transistors of Examples 15, 16 and 17. [Diagram 3] FIG. 2 is a schematic structural diagram of a thin film transistor according to Example 18. [Figure 4] FIG. 13 shows device transport and photogenerated current characteristics of Example 13. [Diagram 5] FIG. 13 shows the device transport and photogenerated current characteristics of Example 14. [Figure 6] FIG. 15 shows device transport and photogenerated current characteristics of Example 15. [Figure 7]FIG. 13 shows the device transport and photogenerated current characteristics of Example 16. [Figure 8] FIG. 17 shows the device transport and photogenerated current characteristics of Example 17. [Figure 9] FIG. 13 shows the device transport and photogenerated current characteristics of Example 18. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The present invention will be further described below with reference to the drawings and specific embodiments. It should be noted that, unless inconsistent, each embodiment or each technical feature described below can be arbitrarily combined to form a new embodiment.

[0030] The following are specific examples of the present invention. The raw materials, equipment, etc. used in the following examples can be purchased unless otherwise specified.

[0031] Example 1: Indium tin zinc oxide semiconductor material doped with praseodymium oxide and europium oxide A set of metal oxide semiconductor materials is obtained by doping indium tin zinc oxide (InSnZnO) with praseodymium oxide as a charge conversion center and doping with europium oxide as a carrier control agent to form an indium tin zinc oxide (Pr-Eu:InSnZnO) semiconductor material co-doped with praseodymium oxide and europium oxide.

[0032] Here, MO is zinc tin oxide, In:Sn:Zn=3:1:1 mol, and is expressed as In(3)Sn(1)Zn(1), and In x (SnZn) y EU n Pr m O zHere, x=0.5, y=0.3333, m=0.05, and n=0.1167. However, in some other embodiments, not limited to the above ratios, x=0.53, y=0.353, m=0.05, and n=0.067, or x=0.56, y=0.373, m=0.05, and n=0.017, or x=0.58, y=0.387, m=0.03, and n=0.003, and will not be described further here.

[0033] Example 2: Indium zinc titanium oxide semiconductor material co-doped with praseodymium oxide and ytterbium oxide A set of metal oxide semiconductor materials is formed by doping indium zinc titanium oxide (InZnTiO) with praseodymium oxide as a charge conversion center and with ytterbium oxide as a carrier control agent to form an indium zinc titanium oxide co-doped with praseodymium oxide and ytterbium oxide (Pr-Yb:InZnTiO) semiconductor material.

[0034] Here, MO is zinc titanium oxide, In:Zn:Ti=4:1:0.05 mol, expressed as In(4)Zn(1)Ti(0.05), In x (ZnTi) y Yb n Pr m O z Here, x=0.75, y=0.1969, m=0.0031, and n=0.05. However, in some other embodiments, not limited to the above ratios, x=0.7, y=0.1838, m=0.0662, and n=0.05, or x=0.65, y=0.17, m=0.13, and n=0.05, and will not be further described here.

[0035] Example 3: Indium gallium zinc oxide semiconductor material co-doped with terbium oxide and europium oxide A set of metal oxide semiconductor materials is obtained by doping indium gallium zinc oxide (InGaZnO) with terbium oxide as a charge conversion center and doping with europium oxide as a carrier control agent to form an indium gallium zinc oxide (Tb-Eu:InGaZnO) semiconductor material co-doped with terbium oxide and europium oxide.

[0036] Here, MO is gallium zinc oxide, In:Ga:Zn=4:0.5:1 mol, and is expressed as In(4)Ga(0.5)Zn(1), and In x (GaZn) y EU n Tb m O z Here, x=0.65, y=0.2438, m=0.05, and n=0.0562. However, in some other embodiments, not limited to the above ratios, x=0.55, y=0.2053, m=0.05, and n=0.1937, or x=0.58, y=0.2175, m=0.05, and n=0.1525, or x=0.6, y=0.225, m=0.05, and n=0.125, and will not be further described here.

[0037] Example 4: Indium gallium zirconium oxide semiconductor material co-doped with terbium oxide and ytterbium oxide A set of metal oxide semiconductor materials is prepared by doping indium gallium zirconium oxide (InGaZrO) with terbium oxide as a charge conversion center and ytterbium oxide as a carrier control agent to form a terbium oxide-ytterbium oxide co-doped indium gallium zirconium oxide (Tb-Yb:InGaZrO) semiconductor material.

[0038] Here, MO is gallium zirconium oxide, and the In:Ga:Zr ratio is 5:1:0.05 mol, and is expressed as In(5)Ga(1)Zr(0.05).x (GaZr) y Yb n Tb m O z Here, x=0.7, y=0.147, m=0.103, and n=0.05. However, in some other embodiments, not limited to the above ratios, x=0.65, y=0.1365, m=0.1635, and n=0.05, or x=0.63, y=0.1323, m=0.1877, and n=0.05, or x=0.74, y=0.1554, m=0.0546, and n=0.05, and will not be further described here.

[0039] Example 5: Cerium oxide, europium oxide co-doped indium zinc oxide semiconductor material A set of metal oxide semiconductor materials is formed by doping indium zinc oxide (InZnO) with cerium oxide as a charge conversion center and europium oxide as a carrier control agent to form an indium zinc oxide co-doped with cerium oxide and europium oxide (Ce-Eu:InZnO) semiconductor material.

[0040] Here, MO is zinc oxide, In:Zn=9:1 mol, and is represented as In(9)Zn(1). x Zinc y EU n Ce m O z Here, x=0.68, y=0.0756, m=0.1944, and n=0.05. However, in some other embodiments, not limited to the above ratios, x=0.7, y=0.0778, m=0.1722, and n=0.05, or x=0.75, y=0.0833, m=0.1167, and n=0.05, or x=0.8, y=0.0889, m=0.0611, and n=0.05, and will not be further described here.

[0041] Example 6: Dysprosium oxide, ytterbium oxide co-doped indium zinc tantalum oxide semiconductor material A set of metal oxide semiconductor materials is formed by doping indium zinc tantalum oxide (InZnTaO) with dysprosium oxide as a charge conversion center and ytterbium oxide as a carrier control agent to form an indium zinc tantalum oxide co-doped with dysprosium oxide and ytterbium oxide (Dy-Yb:InZnTaO) semiconductor material.

[0042] Here, MO is zinc tantalum oxide, In:Zn:Ta=3:1:0.1 mol, and is expressed as In(3)Zn(1)Ta(0.1), and In x (ZnTa) y Yb n Dy m O z Here, x=0.58, y=0.2127, m=0.1573, and n=0.05. However, in some other embodiments, not limited to the above ratios, x=0.6, y=0.22, m=0.13, and n=0.05, or x=0.65, y=0.2383, m=0.0617, and n=0.05, or x=0.68, y=0.2493, m=0.0207, and n=0.05, and will not be further described here.

[0043] Example 7: Indium tin zinc oxide thin film co-doped with praseodymium oxide and europium oxide A set of metal oxide semiconductor thin films, which were formed by magnetron sputtering of the indium tin zinc oxide semiconductor material co-doped with praseodymium oxide and europium oxide of Example 1.

[0044] Example 8: Praseodymium oxide, ytterbium oxide co-doped indium zinc titanium oxide thin film A set of metal oxide semiconductor thin films, which are formed by magnetron sputtering of the indium zinc titanium oxide semiconductor material co-doped with praseodymium oxide and ytterbium oxide of Example 2.

[0045] Example 9: Indium gallium zinc oxide thin film co-doped with terbium oxide and europium oxide A set of metal oxide semiconductor thin films, which were fabricated by magnetron sputtering of the indium gallium zinc oxide semiconductor material co-doped with terbium oxide and europium oxide of Example 3.

[0046] Example 10: Indium gallium zirconium oxide thin film co-doped with terbium oxide and ytterbium oxide A set of metal oxide semiconductor thin films, which were fabricated by magnetron sputtering of the indium gallium zirconium oxide semiconductor material co-doped with terbium oxide and ytterbium oxide of Example 4.

[0047] Example 11: Cerium oxide, europium oxide co-doped indium zinc oxide thin film A set of metal oxide semiconductor thin films, which are prepared by magnetron sputtering of the indium zinc oxide semiconductor material co-doped with cerium oxide and europium oxide of Example 5.

[0048] Example 12: Dysprosium oxide, ytterbium oxide co-doped indium zinc tantalum oxide thin film A set of metal oxide semiconductor thin films, which were fabricated by magnetron sputtering of the indium zinc tantalum oxide semiconductor material co-doped with dysprosium oxide and ytterbium oxide of Example 6.

[0049] Example 13: Thin Film Transistor A pair of thin film transistors adopts a back channel etching type structure, and the schematic structure thereof, as shown in FIG. 1, includes a substrate 01, a gate electrode 05 located on the substrate 01, an insulating layer 04 located on the substrate 01 and the gate electrode 05, a channel layer 03 covering the upper surface of the insulating layer 04 and corresponding to the gate electrode 05, a source electrode 07-1 and a drain electrode 07-2 spaced apart from each other and electrically connected to both ends of the channel layer 03, and a spacer layer 06.

[0050] Here, the substrate 01 is a hard non-alkali glass substrate, on which a buffer layer 02 of silicon oxide is coated.

[0051] The material of the gate electrode 05 is a metal molybdenum / copper (Mo / Cu) laminated structure manufactured by magnetron sputtering, with a thickness of 20 / 400 nm.

[0052] The insulating layer 04 is a stack of silicon nitride (Si3N4) and silicon oxide (SiO2) produced by chemical vapor deposition, with a thickness of 250 / 50 nm, where the silicon nitride is in contact with the gate electrode 05 on the bottom and the silicon oxide is in contact with the channel layer 03 on the top.

[0053] In order to test the effect of different praseodymium oxide contents on device performance, the material of the channel layer 03 is the indium tin zinc oxide semiconductor material co-doped with praseodymium oxide and europium oxide in Example 1, and three ceramic target materials, namely, indium tin zinc oxide (InSnZnO), indium tin zinc oxide doped with europium oxide (Eu:InSnZnO), and indium tin zinc oxide co-doped with praseodymium oxide and europium oxide (Pr-Eu:InSnZnO), are used, and a single target material or two target materials are co-sputtered, and the sputtering power of the two target materials is adjusted to realize the production of thin films with various ratios of components.

[0054] The material of the source electrode 07-1 and the drain electrode 07-2 is a metal molybdenum / copper (Mo / Cu) laminated structure with a thickness of 20 / 400 nm, which is patterned using a commercially available hydrogen peroxide-based etching solution, causing relatively little damage to the channel layer 03 and leaving no obvious etching residue.

[0055] The material of the spacer layer 06 is silicon oxide (SiO2) produced by chemical vapor deposition, the thickness is 300 nm, and the deposition temperature is 250°C.

[0056] The thin film transistor of this embodiment may be an encapsulated structure including only a substrate 01, a gate electrode 05, an insulating layer 04, a channel layer 03, a source electrode 07-1, a drain electrode 07-2, and a spacer layer 06, or may further include a planarizing layer, a reflective electrode, a pixel defining layer, etc., and may be integrated with other devices, etc.

[0057] Here, the thin film patterning process employs a photolithography process, which is combined with a wet or dry etching method.

[0058] The specific parameters and the performance of the manufactured thin film transistor device in this embodiment are as shown in Table 1, where the photo-generated current characteristics are characterized by irradiating the channel layer 03 of the thin film transistor device with a commercially available white LED light source (light intensity set to 10000nits), evaluating the transport characteristics of the device under light irradiation and non-irradiation conditions, and evaluating the intensity by extracting the fluctuations of the threshold voltage and subthreshold swing value of the device, and a large threshold voltage fluctuation range indicates a strong photo-generated current characteristic, and the opposite indicates a weak photo-generated current characteristic. [Table 1] JPEG0007628732000001.jpg247160JPEG0007628732000002.jpg130160

[0059] As can be seen from this Table 1, the doping of praseodymium oxide and europium oxide has a very obvious effect on the performance of the device. First, as shown in Test 1 of Table 1, the device fabricated with indium tin zinc oxide without doping with praseodymium oxide (m=0) and europium oxide (n=0) does not show the "switching" characteristic (conducting state) of a thin film transistor, indicating that the carrier concentration in the thin film is too high. As shown in Test 2 of Table 1, after doping with a certain amount of europium oxide (corresponding to m=0, n=0.05), the device shows the "switching" characteristic, see FIG. 4(a) for details, indicating that doping with europium oxide can effectively suppress the carrier concentration in the thin film, and the corresponding thin film Hall data is as shown in Table 1. Furthermore, as shown in Tests 2 to 8 of Table 2, a series of devices with different praseodymium contents can be fabricated by adjusting the sputtering power of the target material in the co-sputtering. It should be noted that the device without praseodymium oxide doping (corresponding to m=0, n=0.05) has a relatively high mobility, a relatively small subthreshold swing value and a negative threshold voltage, but its photo-generated current characteristic is very strong, that is, under light irradiation conditions, the device characteristics change very obviously (threshold voltage shifts negatively, and subthreshold swing value deteriorates). However, the photo-generated current characteristic of the device doped with a certain amount of praseodymium oxide is obviously suppressed. Of course, with the increase in the praseodymium oxide content, the device characteristics such as mobility are further deteriorated, and the photo-generated current characteristic is further improved. After excessive praseodymium oxide doping (e.g., m=0.15, n=0.05), the device mobility is obviously deteriorated and the device photo-generated current characteristic is very weak, which greatly limits its application field. Therefore, in practical applications, it is necessary to carefully consider the relationship between the two and select an appropriate doping amount.

[0060] The corresponding photocurrent characteristic test was performed on the device fabricated in this example, and the corresponding m values ​​are 0 and 0.05, as shown in Figures 4(b) and 4(c), respectively. When the device is irradiated with light, the threshold voltage of the device not doped with praseodymium oxide (corresponding to m=0, n=0.05) shifts negatively and the subthreshold swing value deteriorates. However, after a certain amount of praseodymium oxide is doped (corresponding to m=0.05, n=0.05), the threshold voltage of the device remains almost unchanged, indicating excellent light irradiation stability, i.e., corresponding to the weak photocurrent characteristic in Table 1.

[0061] As can be seen from the test results of this embodiment, the present invention can effectively control the carrier concentration of the material and improve its photostability by doping a certain amount of praseodymium oxide and europium oxide into the indium tin zinc oxide substrate.

[0062] Example 14: Thin Film Transistor A pair of thin film transistors adopts a back channel etching type structure, and the schematic structure thereof, as shown in FIG. 1, includes a substrate 01, a gate electrode 05 located on the substrate 01, an insulating layer 04 located on the substrate 01 and the gate electrode 05, a channel layer 03 covering the upper surface of the insulating layer 04 and corresponding to the gate electrode 05, a source electrode 07-1 and a drain electrode 07-2 spaced apart from each other and electrically connected to both ends of the channel layer 03, and a spacer layer 06.

[0063] Here, the substrate 01 is a hard non-alkali glass substrate, on which a buffer layer 02 of silicon oxide is coated.

[0064] The material of the gate electrode 05 is a metal molybdenum / copper (Mo / Cu) laminated structure manufactured by magnetron sputtering, with a thickness of 20 / 400 nm.

[0065] The insulating layer 04 is a stack of silicon nitride (Si3N4) and silicon oxide (SiO2) produced by chemical vapor deposition, with a thickness of 250 / 50 nm, where the silicon nitride is in contact with the gate electrode 05 on the bottom and the silicon oxide is in contact with the channel layer 03 on the top.

[0066] In order to test the effect of different ytterbium oxide contents on device performance, the material of the channel layer 03 is the indium zinc titanium oxide semiconductor material co-doped with praseodymium oxide and ytterbium oxide in Example 2, and three ceramic target materials, namely, indium zinc titanium oxide (InZnTiO), indium zinc titanium oxide doped with praseodymium oxide (Pr:InZnTiO), and indium zinc titanium oxide co-doped with praseodymium oxide and ytterbium oxide (Pr-Yb:InZnTiO), are used, and a single target material or two target materials are co-sputtered, and the sputtering power of the two target materials is adjusted to realize the production of thin films with various ratios of components.

[0067] The material of the source electrode 07-1 and the drain electrode 07-2 is a metal molybdenum / copper (Mo / Cu) laminated structure with a thickness of 20 / 400 nm, which is patterned using a commercially available hydrogen peroxide-based etching solution, causing relatively little damage to the channel layer 03 and leaving no obvious etching residue.

[0068] The material of the spacer layer 06 is silicon oxide (SiO2) produced by chemical vapor deposition, the thickness is 300 nm, and the deposition temperature is 250°C.

[0069] The thin film transistor of this embodiment may be an encapsulated structure including only a substrate 01, a gate electrode 05, an insulating layer 04, a channel layer 03, a source electrode 07-1, a drain electrode 07-2, and a spacer layer 06, or may further include a planarizing layer, a reflective electrode, a pixel defining layer, etc., and may be integrated with other devices, etc.

[0070] Here, the thin film patterning process employs a photolithography process, which is combined with a wet or dry etching method.

[0071] The specific parameters and the performance of the manufactured thin film transistor device in this embodiment are as shown in Table 2, where the photo-generated current characteristics are characterized by irradiating the channel layer 03 of the thin film transistor device with a commercially available white LED light source (light intensity set to 10000nits), evaluating the transport characteristics of the device under light irradiation and non-irradiation conditions, and evaluating the intensity by extracting the fluctuations of the threshold voltage and subthreshold swing value of the device, where a large threshold voltage fluctuation range indicates a strong photo-generated current characteristic, and the opposite indicates a weak photo-generated current characteristic. [Table 2] JPEG0007628732000003.jpg246160JPEG0007628732000004.jpg254160JPEG0007628732000005.jpg141160

[0072] As can be seen from Table 2, the doping of praseodymium oxide and ytterbium oxide has a very obvious effect on the performance of the device. First, as shown in Test 1 of Table 2, the device made of indium zinc titanium oxide without doping with praseodymium oxide (m=0) and ytterbium oxide (n=0) does not show the "switching" characteristic (conducting state) of a thin film transistor, indicating that the carrier concentration in the thin film is too high. As shown in Test 2 of Table 2, after doping with a certain amount of praseodymium oxide (m=0.05, corresponding to n=0), the device still does not show the "switching" characteristic, and further, after continuing to dope with a certain amount of ytterbium oxide (m=0.05, corresponding to n=0.0001), the device shows the "switching" characteristic, indicating that the suppression effect of praseodymium oxide on the carrier concentration in the thin film is less significant than that of ytterbium oxide, and the corresponding thin film Hall data is as shown in Table 2. In addition, to further explore the effect of ytterbium oxide, a series of devices with different ytterbium contents can be fabricated by adjusting the sputtering power of the target material in the co-sputtering, as shown in Tests 2 to 8 in Table 2. Specifically, the device doped with a small amount of ytterbium oxide (corresponding to m=0.05, n=0.0001) has a relatively high mobility and a negative threshold voltage. With the increase in ytterbium oxide content, the threshold voltage of the device shifts to the positive side and the mobility rate decreases, indicating that ytterbium oxide can effectively adjust the threshold voltage of the device, that is, the carrier concentration in the thin film, which can be further verified from the Hall data in Table 2. Of course, after excessive ytterbium oxide is doped (e.g., m=0.05, n=0.15), the mobility of the device is obviously deteriorated, which greatly limits its application field. Therefore, in practical applications, it is necessary to carefully consider the relationship between the two and select an appropriate doping amount.

[0073] The corresponding photo-generated current characteristic test was performed on the device fabricated in this embodiment, and as shown in Figures 5(b) and 5(c), the corresponding m values ​​are all 0.05, and the n values ​​are 0.001 and 0.05, respectively. When the device is irradiated with light, the threshold voltage of the device doped with a small amount of ytterbium oxide (m = 0.05, corresponding to n = 0.001) does not shift obviously, and the subthreshold swing value is slightly deteriorated. However, after a certain amount of ytterbium oxide is doped (m = 0.05, corresponding to n = 0.05), the threshold voltage of the device remains almost unchanged, showing excellent light irradiation stability, that is, corresponding to the weak photo-generated current characteristic in Table 2. It should be noted that the photo-generated current characteristics of the devices with different ytterbium contents (m = 0.05, n = 0 to 0.15) are all weak, which indicates that the light stability of the device can be effectively improved by doping with praseodymium oxide.

[0074] As can be seen from the test results of this embodiment, the present invention can effectively control the carrier concentration of the material and improve the photostability by doping a certain amount of praseodymium oxide and ytterbium oxide into the indium zinc titanium oxide substrate.

[0075] Example 15: Thin Film Transistor A pair of thin film transistors adopts a top-gate type self-aligned structure, and the schematic structure thereof, as shown in FIG. 2, includes a substrate 01, a buffer layer 02, a channel layer 03, an insulating layer 04 and a gate electrode 05 located on the channel layer 03, a spacer layer 06 covering the upper surfaces of the channel layer 03 and the gate electrode, and a source electrode 07-1 and a drain electrode 07-2 located on the spacer layer 06 and electrically connected to both ends of the channel layer 03.

[0076] Here, the substrate 01 is a hard glass substrate.

[0077] The buffer layer 02 is silicon oxide produced by plasma enhanced chemical vapor deposition.

[0078] The material of the channel layer 03 is the indium gallium zinc oxide semiconductor material co-doped with terbium oxide and europium oxide of Example 3, and the thickness is 30 nm.

[0079] The insulating layer 04 is made of silicon oxide and has a thickness of 300 nm, and the gate electrode 05 is a titanium / copper (Ti / Cu) laminated structure manufactured by magnetron sputtering and has a thickness of 20 / 400 nm.

[0080] The spacer layer 06 is silicon oxide and has a thickness of 300 nm.

[0081] The material of the source electrode 07-1 and the drain electrode 07-2 is a titanium / copper (Ti / Cu) laminated structure manufactured by magnetron sputtering, and the thickness is 20 / 400 nm.

[0082] In order to test the effect of different europium contents on device performance, the material of the channel layer 03 is the indium gallium zinc oxide semiconductor material co-doped with terbium oxide and europium oxide in Example 3, and three ceramic target materials, namely, indium gallium zinc oxide (InGaZnO), terbium oxide doped gallium zinc oxide (Tb:InGaZnO), and terbium oxide and europium oxide co-doped indium gallium zinc oxide (Tb-Eu:InGaZnO), are used, and a single target material or two target materials are co-sputtered, and the sputtering power of the two target materials is adjusted to realize the production of thin films with various ratios of components.

[0083] The thin film transistor of this embodiment may be an encapsulated structure including only a substrate 01, a channel layer 03, an insulating layer 04, a gate electrode 05, a spacer layer 06, a source electrode 07-1 and a drain electrode 07-2, or may further include a protective layer and a pixel definition layer, etc., and may be integrated with other devices, etc.

[0084] Here, the thin film is patterned by a photolithography process in combination with a wet or dry etching method.

[0085] The specific parameters and performance of the fabricated thin film transistor device in this example are as shown in Table 3, where the photo-generated current characteristic is characterized by illuminating the channel layer of the thin film transistor device with a commercially available white LED light source, evaluating the transport characteristics of the device under various light intensity conditions, and evaluating its intensity by extracting the variation of the threshold voltage of the device, where a large threshold voltage variation range indicates a strong photo-generated current characteristic, and vice versa. [Table 3] JPEG0007628732000006.jpg254160JPEG0007628732000007.jpg254160JPEG0007628732000008.jpg254160JPEG0007628732000009.jpg254160

[0086] As can be seen from Table 3, the doping of terbium oxide and europium oxide has a very obvious effect on the performance of the device. First, as shown in Test 1 in Table 3, the device made of indium gallium zinc oxide without doping terbium oxide (m=0) and europium oxide (n=0) does not show the "switching" characteristic (conducting state) of a thin film transistor, indicating that the carrier concentration in the thin film is too high. As shown in Test 2 in Table 3, after doping with a certain amount of terbium oxide (m=0.05, corresponding to n=0), the device still does not show the "switching" characteristic, and further, after continuing to dope with a certain amount of europium oxide (m=0.05, corresponding to n=0.0001), the device shows the "switching" characteristic, indicating that the suppression effect of terbium oxide on the carrier concentration in the thin film is less significant than that of europium oxide, and the corresponding thin film Hall data is as shown in Table 3. In addition, to further explore the effect of europium oxide, a series of devices with different europium contents can be fabricated by adjusting the sputtering power of the target material in the co-sputtering, as shown in Tests 2 to 8 in Table 3. Specifically, the device doped with a small amount of europium oxide (corresponding to m=0.05, n=0.0001) has a relatively high mobility and a negative threshold voltage. With the increase of europium oxide content, the threshold voltage of the device shifts to the positive direction and the mobility rate decreases, indicating that europium oxide can effectively adjust the threshold voltage of the device, that is, the carrier concentration in the thin film, which can be further verified from the Hall data in Table 3. Of course, after excessive europium oxide is doped (e.g., m=0.05, n=0.15), the mobility of the device is obviously deteriorated, which greatly limits its application field. Therefore, in practical applications, it is necessary to carefully consider the relationship between the two and select an appropriate doping amount.The corresponding photo-generated current characteristic test was performed on the device fabricated in this embodiment, and as shown in Figures 6(b) and 6(c), the corresponding m values ​​are all 0.05, and the n values ​​are 0.001 and 0.05, respectively. When the device is irradiated with light, the threshold voltage of the device doped with a small amount of europium oxide (m = 0.05, corresponding to n = 0.001) does not shift obviously, and the subthreshold swing value is slightly deteriorated. However, after a certain amount of europium oxide is doped (m = 0.05, corresponding to n = 0.05), the threshold voltage of the device remains almost unchanged, showing excellent light irradiation stability, that is, corresponding to the weak photo-generated current characteristic in Table 3. It should be noted that the photo-generated current characteristics of the devices with different europium contents (m = 0.05, n = 0 to 0.15) are all weak, which indicates that the light stability of the device can be effectively improved by doping terbium oxide.

[0087] As can be seen from the test results of this embodiment, the present invention can effectively control the carrier concentration of the material and improve its photostability by doping a certain amount of terbium oxide and europium oxide into the indium gallium zinc oxide substrate.

[0088] Example 16: Thin Film Transistor A pair of thin film transistors adopts a top-gate type self-aligned structure, and the schematic structure thereof, as shown in FIG. 2, includes a substrate 01, a buffer layer 02, a channel layer 03, an insulating layer 04 and a gate electrode 05 located on the channel layer 03, a spacer layer 06 covering the upper surfaces of the channel layer 03 and the gate electrode, and a source electrode 07-1 and a drain electrode 07-2 located on the spacer layer 06 and electrically connected to both ends of the channel layer 03.

[0089] Here, the substrate 01 is a hard glass substrate.

[0090] The buffer layer 02 is silicon oxide produced by plasma enhanced chemical vapor deposition.

[0091] The material of the channel layer 03 is the indium gallium zirconium oxide semiconductor material co-doped with terbium oxide and ytterbium oxide of Example 4, and the thickness is 30 nm.

[0092] The insulating layer 04 is made of silicon oxide and has a thickness of 300 nm, and the gate electrode 05 is made of a titanium / copper (Ti / Cu) laminated structure manufactured by magnetron sputtering and has a thickness of 20 / 400 nm.

[0093] The spacer layer 06 is silicon oxide and has a thickness of 300 nm.

[0094] The material of the source electrode 07-1 and the drain electrode 07-2 is a titanium / copper (Ti / Cu) laminated structure manufactured by magnetron sputtering, and the thickness is 20 / 400 nm.

[0095] In order to test the effect of different ytterbium contents on device performance, the material of the channel layer 03 is the indium gallium zirconium oxide semiconductor material co-doped with terbium oxide and ytterbium oxide in Example 4, and three ceramic target materials, namely, indium gallium zirconium oxide (InGaZrO), indium gallium zirconium oxide doped with terbium oxide (Tb:InGaZrO), and indium gallium zirconium oxide co-doped with terbium oxide and ytterbium oxide (Tb-Yb:InGaZrO), are used, and a single target material or two target materials are co-sputtered, and the sputtering power of the two target materials is adjusted to realize the production of thin films with various ratios of components.

[0096] The thin film transistor of this embodiment may be an encapsulated structure including only a substrate 01, a channel layer 03, an insulating layer 04, a gate electrode 05, a spacer layer 06, a source electrode 07-1 and a drain electrode 07-2, or may further include a protective layer and a pixel definition layer, etc., and may be integrated with other devices, etc.

[0097] Here, the thin film is patterned by a photolithography process in combination with a wet or dry etching method.

[0098] The specific parameters and the performance of the fabricated thin film transistor device in this embodiment are as shown in Table 4, where the photo-generated current characteristic is characterized by illuminating the channel layer 03 of the thin film transistor device with a commercially available white LED light source, evaluating the transport characteristics of the device under light irradiation and non-irradiation conditions, and evaluating its intensity by extracting the variation of the threshold voltage of the device, where a large threshold voltage variation range indicates a strong photo-generated current characteristic, and vice versa indicates a weak photo-generated current characteristic. [Table 4] JPEG0007628732000010.jpg245160JPEG0007628732000011.jpg254160JPEG0007628732 000012.jpg254160JPEG0007628732000013.jpg254160JPEG0007628732000014.jpg19160

[0099] As can be seen from this Table 4, the doping of terbium oxide and ytterbium oxide has a very obvious effect on the performance of the device. First, as shown in Test 1 of Table 4, the device fabricated with indium gallium zirconium oxide without doping with terbium oxide (m=0) and ytterbium oxide (n=0) does not show the "switching" characteristics (conducting state) of a thin film transistor, indicating that the carrier concentration in the thin film is too high. As shown in Test 2 of Table 4, after doping with a certain amount of ytterbium oxide (corresponding to m=0, n=0.05), the device shows the "switching" characteristics, see FIG. 7(a) for details, indicating that doping with ytterbium oxide can effectively suppress the carrier concentration in the thin film, and the corresponding thin film Hall data is as shown in Table 4. Furthermore, as shown in Tests 2 to 8 of Table 4, a series of devices with different terbium contents can be fabricated by adjusting the sputtering power of the target material in the co-sputtering. It should be noted that the device without terbium oxide doping (corresponding to m=0, n=0.05) has a relatively high mobility, a relatively small subthreshold swing value and a negative threshold voltage, but its photo-generated current characteristic is very strong, that is, under light irradiation conditions, the device characteristics change very obviously (threshold voltage shifts negatively, and subthreshold swing value deteriorates). However, the photo-generated current characteristic of the device doped with a certain amount of terbium oxide is obviously suppressed. Of course, with the increase in the terbium oxide content, the device characteristics such as mobility are further deteriorated, and the photo-generated current characteristic is further improved. After excessive terbium oxide doping (e.g., m=0.15, n=0.05), the device mobility is obviously deteriorated and the device photo-generated current characteristic is very weak, which greatly limits its application field. Therefore, in practical applications, it is necessary to carefully consider the relationship between the two and select an appropriate doping amount.

[0100] The corresponding photocurrent characteristic test was performed on the device fabricated in this example. As shown in FIGS. 7(b) and 7(c), the corresponding n values ​​are all 0.05, and the m values ​​are 0 and 0.05, respectively. When the device is irradiated with light, the threshold voltage of the device not doped with terbium oxide (m=0, corresponding to n=0.05) shifts negatively and the subthreshold swing value deteriorates. However, after a certain amount of terbium oxide is doped (m=0.05, corresponding to n=0.05), the threshold voltage of the device remains almost unchanged, indicating excellent light irradiation stability, that is, corresponding to the weak photocurrent characteristic in Table 4.

[0101] As can be seen from the test results of this embodiment, the present invention can effectively control the carrier concentration of the material and improve its photostability by doping a certain amount of terbium oxide and ytterbium oxide into the indium gallium zirconium oxide substrate.

[0102] Example 17: Thin Film Transistor A set of thin film transistors adopts a self-aligned structure, and the schematic structure thereof is shown in FIG. 2 and includes a substrate 01, a buffer layer 02, a channel layer 03, an insulating layer 04 and a gate electrode 05 located on the channel layer 03, a spacer layer 06 covering the upper surfaces of the channel layer 03 and the gate electrode 05, and a source electrode 07-1 and a drain electrode 07-2 located on the spacer layer 06 and electrically connected to both ends of the channel layer 03.

[0103] Here, the substrate 01 is a hard glass substrate.

[0104] The buffer layer 02 is silicon oxide produced by plasma enhanced chemical vapor deposition.

[0105] The material of the channel layer 03 is the indium zinc oxide semiconductor material co-doped with cerium oxide and europium oxide of Example 5, and the thickness is 20 nm.

[0106] The insulating layer 04 is made of silicon oxide and has a thickness of 300 nm, and the gate electrode 05 is a molybdenum / copper / molybdenum (Mo / Cu / Mo) laminated structure manufactured by magnetron sputtering and has thicknesses of 20 / 400 / 50 nm.

[0107] The spacer layer 06 is a silicon oxide thin film fabricated by plasma enhanced chemical vapor deposition and has a thickness of 300 nm.

[0108] The material of the source electrode 07-1 and the drain electrode 07-2 is a molybdenum / copper / molybdenum (Mo / Cu / Mo) laminated structure manufactured by magnetron sputtering, with thicknesses of 20 / 400 / 50 nm.

[0109] The thin film transistor of this embodiment may be an encapsulated structure including only a substrate 01, a channel layer 03, an insulating layer 04, a gate electrode 05, a spacer layer 06, a source electrode 07-1 and a drain electrode 07-2, or may further include a protective layer and a pixel definition layer, etc., and may be integrated with other devices, etc.

[0110] Here, the thin film is patterned by a photolithography process in combination with a wet or dry etching method.

[0111] The specific parameters and the performance of the fabricated thin film transistor device in this embodiment are as shown in Table 5, where the photo-generated current characteristic is characterized by illuminating the channel layer 03 of the thin film transistor device with a commercially available white LED light source, evaluating the transport characteristics of the device under light irradiation and non-irradiation conditions, and evaluating its intensity by extracting the variation of the threshold voltage of the device, where a large threshold voltage variation range indicates a strong photo-generated current characteristic, and vice versa indicates a weak photo-generated current characteristic. [Table 5] JPEG0007628732000015.jpg254160JPEG0007628732000016.jpg254160JPEG0007628732000017.jpg254160JPEG0007628732000018.jpg175160

[0112] As can be seen from this Table 5, the doping of cerium oxide and europium oxide has a very obvious effect on the performance of the device. First, as shown in Test 1 of Table 5, the device fabricated with indium zinc oxide without doping with cerium oxide (m=0) and europium oxide (n=0) does not show the "switching" characteristic (conducting state) of the thin film transistor, indicating that the carrier concentration in the thin film is too high. As shown in Test 2 of Table 5, after doping with a certain amount of europium oxide (corresponding to m=0, n=0.05), the device shows the "switching" characteristic, see FIG. 8(a) for details, indicating that doping with europium oxide can effectively suppress the carrier concentration in the thin film, and the corresponding thin film Hall data is as shown in Table 5. Furthermore, as shown in Tests 2 to 8 of Table 5, a series of devices with different cerium contents can be fabricated by adjusting the components in the mixed solution. It should be noted that the device without cerium oxide doping (corresponding to m=0, n=0.05) has a relatively high mobility, a relatively small subthreshold swing value and a negative threshold voltage, but its photo-generated current characteristic is very strong, that is, under light irradiation conditions, the device characteristics change very obviously (threshold voltage shifts negatively and subthreshold swing value deteriorates). However, the photo-generated current characteristic of the device doped with a certain amount of cerium oxide is obviously suppressed. Of course, with the increase in the cerium oxide content, the device characteristics such as mobility are further deteriorated and the photo-generated current characteristic is further improved. After excessive cerium oxide doping (e.g., m=0.15, n=0.05), the device mobility is obviously deteriorated and the device photo-generated current characteristic is very weak, which greatly limits its application field. Therefore, in practical applications, it is necessary to carefully consider the relationship between the two and select an appropriate doping amount.

[0113] The corresponding photocurrent characteristic test was performed on the device fabricated in this example. As shown in FIGS. 8(b) and 8(c), the corresponding n values ​​are all 0.05, and the m values ​​are 0 and 0.05, respectively. When the device is irradiated with light, the threshold voltage of the device not doped with cerium oxide (m=0, corresponding to n=0.05) shifts negatively and the subthreshold swing value deteriorates. However, after a certain amount of cerium oxide is doped (m=0.05, corresponding to n=0.05), the threshold voltage of the device remains almost unchanged, indicating excellent light irradiation stability, that is, corresponding to the weak photocurrent characteristic in Table 5.

[0114] As can be seen from the test results of this embodiment, the present invention can effectively control the carrier concentration of the material and improve its photostability by doping a certain amount of cerium oxide and europium oxide into the indium zinc oxide substrate.

[0115] Example 18: Thin Film Transistor A pair of thin film transistors adopts an etching stopper type structure, and the schematic structural diagram thereof, as shown in FIG. 3, includes a substrate 01, a gate electrode 05 located on the substrate 01, an insulating layer 04 located on the substrate 01 and the gate electrode 05, a channel layer 03 covering the upper surface of the insulating layer 04 and corresponding to the gate electrode 05, an etching stopper layer 08, a source electrode 07-1 and a drain electrode 07-2 spaced apart from each other and electrically connected to both ends of the channel layer 03, and a spacer layer 06.

[0116] Here, the substrate 01 is a glass substrate, on which a buffer layer 02 of silicon oxide is coated.

[0117] The material of the gate electrode 05 is a molybdenum aluminum molybdenum (Mo / Al / Mo) metal laminate structure manufactured by magnetron sputtering, with thicknesses of 50 / 300 / 50 nm.

[0118] The insulating layer 04 is a stack of silicon nitride (Si3N4) and silicon oxide (SiO2) produced by chemical vapor deposition, with a thickness of 250 / 50 nm, where the silicon nitride is in contact with the gate electrode 05 on the bottom and the silicon oxide is in contact with the channel layer 03 on the top.

[0119] In order to test the effect of different dysprosium oxide contents on device performance, the material of the channel layer 03 is the indium zinc tantalum oxide semiconductor material co-doped with dysprosium oxide and ytterbium oxide in Example 6, and three ceramic target materials, namely, indium zinc tantalum oxide (InZnTaO), indium zinc tantalum oxide doped with ytterbium oxide (Yb:InZnTaO), and indium zinc tantalum oxide co-doped with dysprosium oxide and ytterbium oxide (Dy-Yb:InZnTaO), are used, and a single target material or two target materials are co-sputtered, and the sputtering power of the two target materials is adjusted to realize the production of thin films with various ratios of components.

[0120] The material of the etching stopper layer 08 and the spacer layer 06 is silicon oxide (SiO2) manufactured by chemical vapor deposition, the thickness is 300 nm, and the deposition temperature is 300°C.

[0121] The material of the source electrode 07-1 and the drain electrode 07-2 is a metal molybdenum aluminum molybdenum (Mo / Al / Mo) laminated structure with thicknesses of 50 / 300 / 50 nm.

[0122] In addition, the thin film transistor of this embodiment may have a sealing structure including only the substrate 01, the gate electrode 05, the insulating layer 04, the channel layer 03, the etching stopper layer 08, the source electrode 07-1, the drain electrode 07-2, and a protective layer, or may further include a flat layer, a reflective electrode, a pixel definition layer, etc., and may be integrated with other devices, etc.

[0123] Here, the thin film patterning process employs a photolithography process, which is combined with a wet or dry etching method.

[0124] The specific parameters and the performance of the fabricated thin film transistor device in this embodiment are as shown in Table 6, where the photo-generated current characteristic is characterized by illuminating the channel layer 03 of the thin film transistor device with a commercially available white LED light source, evaluating the transport characteristics of the device under light irradiation and non-irradiation conditions, and evaluating its intensity by extracting the variation of the threshold voltage of the device, where a large threshold voltage variation range indicates a strong photo-generated current characteristic, and vice versa indicates a weak photo-generated current characteristic. [Table 6] JPEG0007628732000019.jpg254160JPEG0007628732000020.jpg254160JPEG00076287320 00021.jpg254160JPEG0007628732000022.jpg254160JPEG0007628732000023.jpg115160

[0125] As can be seen from this Table 6, the doping of dysprosium oxide and ytterbium oxide has a very obvious effect on the performance of the device. First, as shown in Test 1 of Table 6, the device fabricated with indium zinc tantalum oxide without doping with dysprosium oxide (m=0) and ytterbium oxide (n=0) does not show the "switching" characteristic (conducting state) of the thin film transistor, indicating that the carrier concentration in the thin film is too high. As shown in Test 2 of Table 6, after doping with a certain amount of ytterbium oxide (corresponding to m=0, n=0.05), the device shows the "switching" characteristic, see FIG. 9(a) for details, indicating that doping with ytterbium oxide can effectively suppress the carrier concentration in the thin film, and the corresponding thin film Hall data is as shown in Table 6. Furthermore, as shown in Tests 2 to 8 of Table 6, a series of devices with different dysprosium contents can be fabricated by adjusting the sputtering power of the corresponding target materials. It should be noted that the device without dysprosium oxide doping (corresponding to m=0, n=0.05) has a relatively high mobility, a relatively small subthreshold swing value and a negative threshold voltage, but its photo-generated current characteristic is very strong, that is, under light irradiation conditions, the device characteristics change very obviously (threshold voltage shifts negatively and subthreshold swing value deteriorates). However, the photo-generated current characteristic of the device doped with a certain amount of dysprosium oxide is obviously suppressed. Of course, with the increase in the dysprosium oxide content, the device characteristics such as mobility are further deteriorated, and the photo-generated current characteristic is further improved. After excessive dysprosium oxide doping (e.g., m=0.15, n=0.05), the device mobility is obviously deteriorated and the device photo-generated current characteristic is very weak, which greatly limits its application field. Therefore, in practical applications, it is necessary to carefully consider the relationship between the two and select an appropriate doping amount.

[0126] The corresponding photocurrent characteristic test was performed on the device fabricated in this example. As shown in Figures 9(b) and 9(c), the corresponding n values ​​are all 0.05, and the m values ​​are 0 and 0.05, respectively. When the device is irradiated with light, the threshold voltage of the device not doped with dysprosium oxide (m=0, corresponding to n=0.05) shifts negatively and the subthreshold swing value deteriorates. However, after a certain amount of dysprosium oxide is doped (m=0.05, corresponding to n=0.05), the threshold voltage of the device remains almost unchanged, indicating excellent light irradiation stability, that is, corresponding to the weak photocurrent characteristic in Table 6. As can be seen from the test results of this embodiment, the present invention can effectively control the carrier concentration of the material and improve its light stability by doping a certain amount of dysprosium oxide and ytterbium oxide into the indium zinc tantalum oxide substrate.

[0127] Example 19: Display Panel A display panel, comprising the thin film transistor in the above Examples 13-18, wherein the thin film transistor is used to drive a display unit in the display panel.

[0128] Example 20: Detector A detector, comprising the thin film transistor in the above Examples 13-18, wherein the thin film transistor is used to drive the detection unit of the detector.

[0129] Each functional layer of the thin film transistor according to the embodiment of the present invention will be further described below.

[0130] The substrate in the present invention is not particularly limited, and may be a substrate 01 well known in the art. For example, it may be a hard alkali glass, non-alkali glass, quartz glass, silicon substrate, or may be flexible polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS), polysulfonic acid ether (PES), or a metal sheet.

[0131] The material of the gate electrode 05 in the present invention is not particularly limited and may be arbitrarily selected from materials well known in the art, such as transparent conductive oxides (ITO, AZO, GZO, IZO, ITZO, FTO, etc.), metals (Mo, Al, Cu, Ag, Ti, Au, Ta, Cr, Ni, etc.) and their alloys, and composite conductive thin films formed of metals and oxides (ITO / Ag / ITO, IZO / Ag / IZO, etc.), and stacked layers of metals and metals (Mo / Al / Mo, Ti / Al / Ti, etc.).

[0132] Methods for manufacturing the thin film of the gate electrode 05 include sputtering, plating, thermal evaporation and other deposition methods, but the sputtering deposition method is preferred, because the thin film manufactured by this method has good adhesion to the substrate 01, is highly uniform, and can be made large in area.

[0133] Here, the specific structure of the gate electrode is determined by the technical parameters to be achieved, for example, a transparent electrode needs to be used for a transparent display, which may be a single layer of ITO or ITO / Ag / ITO as the gate electrode, etc. In addition, in special applications that require high-temperature processes, a high-temperature resistant metal alloy thin film may be selected as the gate electrode.

[0134] The material of the insulating layer 04 in the present invention is not particularly limited, and may be arbitrarily selected from materials well known in the art, such as silicon oxide, silicon nitride, aluminum oxide, tantalum oxide, hafnium oxide, yttrium oxide, and polymer organic film layers.

[0135] It should be noted that the components of these insulating thin films do not have to match the theoretical chemical ratio. The insulating layer 04 may be formed by stacking multiple insulating films, which can provide better insulating properties on the one hand and improve the interface properties between the channel layer 03 and the insulating layer 04 on the other hand. The insulating layer 04 may be manufactured by a variety of methods, such as physical vapor deposition, chemical vapor deposition, atomic layer deposition, laser deposition, anodization, or solution deposition.

[0136] The etching solution used in the wet etching includes a mixture of phosphoric acid, nitric acid and glacial acetic acid, or a mixture of hydrogen peroxide. The etching rate of the metal oxide semiconductor material in the hydrogen peroxide-based etching solution is less than 1 nm / min. The dry etching may illustratively be a plasma etching process, and the etching gas includes a chlorine-based gas or a fluorine-based gas.

[0137] When using vacuum magnetron sputtering for metal oxide semiconductor materials, single target material sputtering or multi-target material co-sputtering may be selected, with single target material sputtering being preferred.

[0138] Single target material sputtering can provide more reproducible and stable films, the film microstructure is easier to control, and the sputtered particles are not perturbed to a greater extent by the recombination process as in co-sputtered films.

[0139] In the vacuum sputter deposition process, the power source may be selected as radio frequency (RF) sputter, direct current (DC) sputter or alternating current (AC) sputter, preferably AC sputter, which is commonly used in industry.

[0140] In the sputter deposition process, the sputtering pressure is selectively 0.1 Pa to 10 Pa, preferably 0.3 Pa to 0.7 Pa.

[0141] If the sputtering pressure is too low, stable glow sputtering cannot be maintained, and if the sputtering pressure is too high, the sputtered particles will be scattered significantly during film formation on the substrate 01, resulting in large energy loss and a decrease in kinetic energy after reaching the substrate 01, increasing the number of defects in the thin film that is formed, and significantly affecting device performance.

[0142] In the sputter deposition process, the oxygen partial pressure is optionally 0-1 Pa, preferably 0.001-0.5 Pa, and more preferably 0.01-0.1 Pa.

[0143] Generally, in the process of manufacturing oxide semiconductor by sputtering, the oxygen partial pressure directly affects the carrier concentration and introduces some oxygen vacancy-related defects. If the oxygen content is too low, it may cause severe oxygen mismatch in the thin film and increase the carrier concentration, and if the oxygen vacancy is too high, it will cause many weak bonds and reduce the reliability of the device.

[0144] In the sputter deposition process, the substrate temperature is preferably 200-300°C.

[0145] In the deposition process of the channel layer thin film, a constant substrate temperature can effectively improve the bonding pattern after the sputtered particles reach the substrate 01, reduce the probability of weak bonds, and improve the stability of the device. Of course, this effect can also be achieved by a process such as a subsequent annealing treatment.

[0146] The thickness of the channel layer 03 is selectively 2 to 100 nm, preferably 5 to 50 nm, and more preferably 20 to 40 nm.

[0147] The material of the source / drain electrodes in the present invention is not particularly limited, and may be selected from any material known in the art as long as it does not affect the realization of various required structural devices. For example, transparent conductive oxides (ITO, AZO, GZO, IZO, ITZO, FTO, etc.), metals (Mo, Al, Cu, Ag, Ti, Au, Ta, Cr, Ni, etc.) and their alloys, and composite conductive thin films formed of metals and oxides (ITO / Ag / ITO, IZO / Ag / IZO, etc.), and stacked layers of metals and metals (Mo / Al / Mo, Ti / Al / Ti, etc.).

[0148] Methods for manufacturing the thin film of the source / drain electrodes include sputtering, thermal evaporation, and other deposition methods, but the sputtering deposition method is preferred, because the thin film manufactured by this method has good adhesion to the substrate 01, is highly uniform, and can be made large in area.

[0149] Here, it should be particularly noted that when manufacturing a device with a back channel etching structure, the source drain electrode and the channel layer 03 need to have a suitable etching selectivity, otherwise the device cannot be manufactured. In the embodiment of the present invention, the wet etching solution is a metal-based etching solution (e.g., hydrogen peroxide-based etching solution) that is common in the industrial field, because the metal oxide semiconductor material of the present invention can effectively resist etching by the wet hydrogen peroxide-based etching solution, and has a very high etching selectivity between it and metals (e.g., molybdenum, molybdenum alloy, molybdenum / aluminum / molybdenum, etc.), and the metal oxide semiconductor layer is hardly affected by the etching solution, so that the performance of the manufactured device is excellent and the stability is high. In addition, the dry etching in the embodiment of the present invention is by an etching gas (e.g., chlorine-based gas, fluorine-based gas, etc.) that is common in the industrial field, and has a small effect on the oxide semiconductor layer of the present invention, and the manufactured device has excellent characteristics and high stability.

[0150] The material of the protective layer in the present invention is not particularly limited, and may be arbitrarily selected from materials well known in the art, such as silicon oxide, silicon nitride, aluminum oxide, tantalum oxide, hafnium oxide, yttrium oxide, and polymer organic film layers.

[0151] It should be noted that the components of these insulating thin films do not have to match the theoretical chemical ratios. The insulating layer 04 may be formed by stacking multiple insulating films, which can provide better insulating properties on the one hand and improve the interface properties between the channel layer 03 and the protective layer on the other hand. The protective layer may be manufactured by a variety of methods, such as physical vapor deposition, chemical vapor deposition, atomic layer deposition, laser deposition, or solution deposition.

[0152] The process for manufacturing the thin film transistor according to the embodiment of the present invention will be further described below.

[0153] In comparison, films produced by sputtering, due to the involvement of high energy plasma, generally have a high deposition rate and do not allow the thin film enough time to undergo relaxation treatment during deposition, which may result in a certain percentage of dislocations and stress remaining in the thin film, which may require a subsequent thermal annealing treatment to continue to reach a desired relative steady state and improve the performance of the thin film.

[0154] In the embodiment of the present invention, the annealing process is mostly provided after the deposition of the channel layer 03 and after the deposition of the protective layer. On the one hand, the annealing process after the deposition of the channel layer 03 can effectively improve the in-situ defects in the channel layer 03 and improve the ability of the channel layer 03 to withstand possible damage in the subsequent processes. On the other hand, the subsequent protective layer deposition process may require an "activation" process to further eliminate the effects of interface states and some donor doping due to the participation of plasma and the modifying effect of active radicals.

[0155] In the practice of the present invention, the treatment method may not only be a heat treatment, but may also include a plasma treatment interface (eg, an insulating layer 04 / semiconductor interface, a channel layer 03 / protective layer interface, etc.).

[0156] Through the above treatment process, the performance of the device can be effectively improved and the stability of the device can be improved.

[0157] The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples. Any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principles of the present invention should be equivalent substitution methods, and all fall within the protection scope of the present invention. [Explanation of symbols]

[0158] 01, substrate 02, buffer layer 03, channel layer 04, insulating layer 05, gate electrode 06, spacer layer 07-1, source electrode 07-2, drain electrode 08, etching barrier layer.

Claims

1. A metal oxide semiconductor, which is a metal oxide semiconductor containing indium, MO-In ２ O ３ A semiconductor is doped with at least two oxides of rare earth elements R and R', respectively, and In ｘ M ｙ R ｎ R' ｍ O ｚ forming a semiconductor material, wherein x+y+m+n=1, 0.4≦x<0.9999, 0≦y<0.5, 0.0001≦(m+n)≦0.2, m>0, n>0, and z>0; In the MO, M is one or a combination of any two or more of Zn, Ga, Sn, Ge, Sb, Al, Mg, Ti, Zr, Hf, Ta, and W; The oxide of the rare earth element R is a carrier concentration control agent, and is one or a combination of two materials selected from the group consisting of ytterbium oxide and europium oxide, and the rare earth element R is doped in the form of a divalent ion.

2. The oxide of the rare earth element R' is a light stabilizer. The metal oxide semiconductor of claim 1 .

3. The oxide of the rare earth element R' is one of praseodymium oxide, terbium oxide, cerium oxide, and dysprosium oxide, or a combination of any two or more of these materials. The metal oxide semiconductor of claim 1 .

4. The metal oxide semiconductor is manufactured and deposited by a method using any one of a physical vapor deposition process, a chemical vapor deposition process, an atomic layer deposition process, a laser deposition process, a reactive ion deposition process, and a solution deposition process. The metal oxide semiconductor of claim 1 .

5. 2. A thin film transistor comprising: a gate electrode; an active layer; an insulating layer located between the gate electrode and the active layer; a source electrode and a drain electrode electrically connected to both ends of the active layer, respectively; and a spacer layer, wherein the active layer is the metal oxide semiconductor according to claim 1.

6. The spacer layer is a thin film of silicon oxide, silicon nitride, or silicon oxynitride manufactured by plasma enhanced chemical vapor deposition, or a laminated structure of any two or more of the thin films. The thin film transistor according to claim 5 .

7. A display panel or detector comprising a thin film transistor according to claim 5.

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