CN112582466A

CN112582466A - Metal oxide semiconductor, thin film transistor and application

Info

Publication number: CN112582466A
Application number: CN202011314502.3A
Authority: CN
Inventors: 徐苗; 徐华; 李民; 彭俊彪; 王磊; 邹建华; 陶洪
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2020-11-20
Filing date: 2020-11-20
Publication date: 2021-03-30
Also published as: JP2023550623A; WO2022105174A1

Abstract

The invention discloses a metal oxide semiconductor, which is characterized in that: in a metal oxide MO-In containing indium₂O₃In is formed by doping at least two kinds of rare earth element R oxide and rare earth element R' oxide, respectively_xM_yR_nR’_mO_zA semiconductor material. The invention introduces the oxides of the rare earth elements R and R 'into the metal oxide containing indium to be respectively used as the carrier control and the light stability enhancement, utilizes the extremely high oxygen bond-breaking energy in the oxide of the rare earth element R to further effectively control the carrier concentration in a semiconductor, and simultaneously utilizes the characteristic that the radius of the rare earth ions is equivalent to that of the indium ions in the indium oxide, and the 4f orbital structure in the rare earth element R' ions and the 5s orbital of the indium ions can form an efficient charge conversion center to improve the electrical stability, particularly the stability under the light irradiation. The invention also provides a method based onThe thin film transistor of the metal oxide semiconductor and the application thereof.

Description

Metal oxide semiconductor, thin film transistor and application

Technical Field

The invention relates to the field of semiconductor manufacturing, in particular to a material and a device structure for manufacturing a metal oxide semiconductor thin film transistor backboard in flat panel display and detector application, and specifically relates to a metal oxide semiconductor, a thin film transistor and application.

Background

In the conventional metal oxide semiconductor system, indium ion (In)³⁺) Due to the relatively large ionic radius, the higher probability of orbital overlap in the multi-element metal oxide ensures the efficient carrier transport channel, and the 5s orbital is the main electron transport channel. However, since the bond breaking energy of In-O after indium is bonded to oxygen is low, indium oxide (In) is used alone₂O₃) A large number of oxygen vacancy defects are present in the film. And oxygen vacancies are a major cause of deterioration in the stability of the metal oxide thin film transistor. On the other hand, the conventional sputtering film-formed indium oxide has more lattice mismatch, so that the carrier mobility of the thin film is low, and the application of the thin film in a high-performance thin film transistor is limited. Usually, doping and In are required³⁺Ga of equivalent ion number³⁺The ions regulate and control oxygen vacancies. Meanwhile, in order to ensure the performance uniformity of the semiconductor device, the metal oxide semiconductor thin film is required to maintain an amorphous thin film structure.

Due to the crystal structure of ZnO and In₂O₃And Ga₂O₃The crystal structures of the two materials are different greatly, so that Zn ions with the amount equivalent to that of In ions are doped into the film, the crystallization of the materials can be inhibited, and the amorphous structure of the film can be maintained. Therefore, IGZO (In: Ga: Zn ═ 1:1:1mol) is most widely used In the current metal oxide semiconductor materials.

However, IGZO also has some problems: ga³⁺And Zn²⁺Large amount of added ions, largeGreatly dilute In³⁺And thus the overlapping degree of the 5s orbitals is reduced, and the electron mobility is lowered.

In addition, IGZO and the like materials have a large number of trap states near the valence band. This causes generation of photogenerated carriers even when the light irradiation energy is lower than the forbidden band width, resulting in a problem that the current metal oxide semiconductor has poor light stability.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a metal oxide semiconductor with relatively high mobility and strong light stability, which is a new co-doping strategy, and by utilizing the special 4f electron orbit characteristic of rare earth oxide, the metal oxide semiconductor with high light stability can be obtained by controlling the carrier concentration while realizing high mobility In an oxide film with high In ratio.

The new co-doping strategy of the invention is to simultaneously introduce two rare earth element R oxide materials and rare earth element R ' oxide materials with different functions into indium-containing metal oxide, wherein the rare earth element R oxide is a carrier concentration control agent, the rare earth element R ' oxide is a light stabilizer, namely the rare earth element R ' oxide is a charge conversion center, and the function principle is as follows:

the carrier concentration control agent is Yb in ytterbium oxide and europium oxide using an oxide of a rare earth element R²⁺Ions and Eu²⁺The ions have full and half full 4f electron orbits, respectively. Therefore, the divalent ions in the oxide of the rare earth element R have lower energy in the oxide than the trivalent ions. In an oxide semiconductor, for In³⁺When the ion substitution is doping, the carrier concentration can be obviously reduced. Meanwhile, because the bond breaking enthalpy changes (delta Hf298) of Yb-O and Eu-O are 715.1kJ/mol and 557.0kJ/mol respectively, which are both far larger than the bond breaking energy (360.0kJ/mol) of In-O, the oxygen vacancy concentration can be effectively controlled. In summary, In combination with the above two features, the introduction of the oxide of the rare earth element R can effectively control the oxygen vacancy of the oxide semiconductor thin film In the high In system, In which Yb is due to²⁺Ionic radius of (D) compared with Eu²⁺Smaller, is more beneficial to reducing the distance of In-In the oxide semiconductor, and therefore can better keep the good high mobility characteristic.

The light stabilizer utilizes the characteristic that the radius of rare earth ions of materials such as praseodymium oxide, terbium oxide, cerium oxide, dysprosium oxide and the like in the oxide of the rare earth element R' is equivalent to that of indium ions in indium oxide, and the 4f orbital electronic structure in the rare earth ions and the 5s orbital of the indium ions can form an efficient charge conversion center so as to improve the electrical stability, particularly the stability under illumination.

The second objective of the present invention is to provide a thin film transistor including the metal oxide semiconductor.

The invention also provides the application of the thin film transistor.

The invention is realized by adopting the following technical scheme:

a metal oxide semiconductor, the metal oxide semiconductor being: in a metal oxide MO-In containing indium₂O₃In is formed by doping at least two kinds of rare earth element R oxide and rare earth element R' oxide, respectively_xM_yR_nR’_mO_zThe semiconductor material is characterized in that x + y + m + n is 1, x is more than or equal to 0.4 and less than 0.9999, y is more than or equal to 0 and less than 0.5, m is more than or equal to 0.0001 and less than or equal to 0.2, n is more than 0, and z is more than 0.

Namely, the metal oxide semiconductor provided by the invention is a composite semiconductor based on indium oxide, and two types of rare earth oxides with different functions but complementary functions are introduced by a co-doping method. Wherein the oxide of the rare earth element R can be selected from ytterbium oxide and europium oxide, which are used as carrier concentration control agents, and Yb in the ytterbium oxide and the europium oxide is utilized²⁺Ions and Eu²⁺Ions, having full and half full 4f electron orbitals, respectively. Therefore, the divalent ions in the oxide of the rare earth element R have lower energy in the oxide than the trivalent ions. In an oxide semiconductor, for In³⁺When the ion substitution is doping, the carrier concentration can be obviously reduced. Meanwhile, because the bond breaking enthalpy change (delta Hf298) of Yb-O and Eu-O is 715.1kJ/mol and 557.0kJ/mol respectively, the bond breaking enthalpy change is far larger than that of In-OCan (360.0kJ/mol) and further can effectively control the concentration of oxygen vacancies. By combining the two characteristics, the introduction of the oxide of the rare earth element R can effectively control the oxygen vacancy of the oxide semiconductor film under a high In system. Wherein due to Yb²⁺Ionic radius of (D) compared with Eu²⁺Smaller, is more beneficial to reducing the distance of In-In the oxide semiconductor, and therefore can better keep the good high mobility characteristic.

Meanwhile, the oxide of the rare earth element R' can be selected from praseodymium oxide, terbium oxide, cerium oxide and dysprosium oxide. The material selection utilizes the structural characteristics of 4f orbit electrons in rare earth ions, and the materials and a 5s orbit of indium ions can form a high-efficiency charge conversion center. Under positive bias, the rare earth ions are in a stable low energy state, the film has higher carrier concentration due to the modulation effect of the Fermi level, and the carrier scattering effect caused by the conversion center can be effectively shielded, so that the electrical property and the like of the device are not obviously influenced. Under negative bias, the electron orbit of the rare earth element 4f and the 5s orbit of indium are coupled, and the rare earth ion is in an unstable activation state. On one hand, the off-state current of the device is increased, and the scattering effect of the device on carriers is enhanced, so that the subthreshold swing of the device is slightly increased; on the other hand, when suitable light excites a photogenerated carrier, the photogenerated electron is rapidly captured by the activated conversion center, and the photogenerated carrier and the ionized oxygen vacancy are recombined in a non-radiative transition mode through the coupling orbit, and the activated state is restored by the activated center. Therefore, the conversion center can provide a fast recombination channel of photon-generated carriers, and the influence on I-V characteristics and stability is avoided. Greatly improving the stability of the metal oxide semiconductor device under illumination.

Further, the oxide of the rare earth element R is a carrier concentration control agent; the oxide of the rare earth element R is one or the combination of two materials of ytterbium oxide and europium oxide.

Further, the oxide of the rare earth element R' is a light stabilizer; the oxide of the rare earth element R' is one or the combination of more than two of praseodymium oxide, terbium oxide, cerium oxide and dysprosium oxide.

In the MO, M is one or the combination of any two or more of Zn, Ga, Sn, Ge, Sb, Al, Mg, Ti, Zr, Hf, Ta and W.

Further, the metal oxide semiconductor is prepared into a film 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 process.

The second purpose of the invention is realized by adopting the following technical scheme:

a thin film transistor comprises a grid electrode, an active layer, an insulating layer positioned between the grid electrode and the active layer, a source electrode and a drain electrode which are respectively and electrically connected with two ends of the active layer, and a spacing layer, and is characterized in that the active layer is the metal oxide semiconductor.

That is, the present invention also provides a thin film transistor formed on the basis of an active layer formed on the metal oxide semiconductor by simultaneously introducing two kinds of rare earth element R oxide and rare earth element R 'oxide having different functions into an indium-containing metal oxide, wherein the rare earth element R oxide serves as a carrier concentration control agent and the rare earth element R' oxide serves as a light stabilizer, so that it can maintain good high mobility characteristics and can improve its electrical stability, particularly stability under light irradiation.

Furthermore, the spacing layer is one structure or a laminated structure consisting of more than two of silicon oxide films, silicon nitride films and silicon oxynitride films prepared by adopting a plasma enhanced chemical vapor deposition mode.

The third purpose of the invention is realized by adopting the following technical scheme:

the thin film transistor is applied to a display panel or a detector.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, through a new co-doping strategy, two rare earth oxide materials with different functions are introduced into the indium-based metal oxide, the control of the carrier concentration is realized at the same time, the effect of good device light stability is achieved, and a brand-new idea is provided for realizing a high-performance metal oxide semiconductor material in the future.

The invention relates to a metal oxide semiconductor formed by introducing at least two oxides of rare earth elements R and R 'into an indium-containing metal oxide, wherein the oxide of the rare earth element R is used as a carrier for control, and the oxide of the rare earth element R' is used for enhancing the light stability, and the purpose is to effectively control the carrier concentration in the oxide semiconductor by utilizing the extremely high oxygen bond-breaking energy in the oxide of the rare earth element R. Meanwhile, the characteristic that the radius of the rare earth ions is equivalent to that of the indium ions in the indium oxide is utilized, and the 4f orbital electronic structure in the rare earth element R' ions and the 5s orbital of the indium ions can form a high-efficiency charge conversion center so as to improve the electrical stability, particularly the stability under illumination.

Drawings

Fig. 1 is a schematic structural view of thin film transistors according to embodiments 13 and 14;

fig. 2 is a schematic view of the structures of thin film transistors of example 15, example 16, and example 17;

fig. 3 is a schematic structural view of a thin film transistor according to embodiment 18;

FIG. 4 is a graph showing the transfer characteristics and the photo-generated current characteristics of the device of example 13;

FIG. 5 is a graph showing the transfer characteristics and the photo-generated current characteristics of the device of example 14;

FIG. 6 is a graph showing the transfer characteristics and the photo-generated current characteristics of the device of example 15;

FIG. 7 is a graph showing the transfer characteristics and the photo-generated current characteristics of the device of example 16;

FIG. 8 is a graph showing the transfer characteristics and the photo-generated current characteristics of the device of example 17;

FIG. 9 is a graph showing the transfer characteristics and the photo-generated current characteristics of the device of example 18.

In the figures, the various reference numbers: 01. a substrate; 02. a buffer layer; 03. a channel layer; 04. an insulating layer; 05. a gate electrode; 06. a spacer layer; 07-1, a source electrode; 07-2, a drain electrode; 08. and etching the barrier layer.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

The following are specific examples of the present invention, and raw materials, equipments and the like used in the following examples can be obtained by purchasing them unless otherwise specified.

Example 1: praseodymium oxide and europium oxide doped indium tin zinc oxide semiconductor material

A group of metal oxide semiconductor materials, the group of metal oxide semiconductor materials being: praseodymium oxide is doped into indium tin zinc oxide (InSnZnO) to serve as a charge conversion center, europium oxide is doped to serve as a carrier control agent, and the semiconductor material of praseodymium oxide and europium oxide codoped indium tin zinc oxide (Pr-Eu: InSnZnO) is formed.

Wherein MO is tin zinc oxide, In: sn: Zn ═ 3:1:1mol, denoted In (3) Sn (1) Zn (1); in_x(SnZn)_yEu_nPr_mO_zWherein x is 0.5, y is 0.3333, m is 0.05, and n is 0.1167. In other embodiments, x is 0.53, y is 0.353, m is 0.05, and n is 0.067, or x is 0.56, y is 0.373, m is 0.05, and n is 0.017, or x is 0.58, y is 0.387, m is 0.03, and n is 0.003, which are not repeated herein.

Example 2: praseodymium oxide and ytterbium oxide co-doped indium zinc titanium oxide semiconductor material

A group of metal oxide semiconductor materials, the group of metal oxide semiconductor materials being: praseodymium oxide is doped into indium zinc titanium oxide (InZnTiO) to serve as a charge conversion center, ytterbium oxide is doped to serve as a carrier control agent, and the semiconductor material of praseodymium oxide and ytterbium oxide codoped indium zinc titanium oxide (Pr-Yb: InZnTiO) is formed.

Wherein MO is zinc titanium oxide, In: zn: t isi ═ 4:1:0.05mol, denoted In (4) Zn (1) Ti (0.05); in_x(ZnTi)_yYb_nPr_mO_zWherein x is 0.75, y is 0.1969, m is 0.0031, and n is 0.05. But not limited to the above ratio, in other embodiments, x is 0.7, y is 0.1838, m is 0.0662, and n is 0.05, or x is 0.65, y is 0.17, m is 0.13, and n is 0.05, which are not repeated herein.

Example 3: terbium oxide and europium oxide co-doped indium gallium zinc oxide semiconductor material

A group of metal oxide semiconductor materials, the group of metal oxide semiconductor materials being: terbium oxide is doped into indium gallium zinc oxide (InGaZnO) to serve as a charge conversion center, europium oxide is doped to serve as a carrier control agent, and the semiconductor material of terbium oxide and europium oxide co-doped indium gallium zinc oxide (Tb-Eu: InGaZnO) is formed.

Wherein MO is gallium zinc oxide, In: ga: Zn ═ 4:0.5:1mol, labeled In (4) Ga (0.5) Zn (1); in_x(GaZn)_yEu_nTb_mO_zWherein x is 0.65, y is 0.2438, m is 0.05, and n is 0.0562. In other embodiments, x is 0.55, y is 0.2053, m is 0.05, and n is 0.1937, or x is 0.58, y is 0.2175, m is 0.05, and n is 0.1525, or x is 0.6, y is 0.225, m is 0.05, and n is 0.125, which are not repeated herein.

Example 4: terbium oxide and ytterbium oxide co-doped indium gallium zirconium oxide semiconductor material

A group of metal oxide semiconductor materials, the group of metal oxide semiconductor materials being: terbium oxide is doped into indium gallium zirconium oxide (InGaZrO) to serve as a charge conversion center, ytterbium oxide is doped to serve as a carrier control agent, and the semiconductor material of the terbium oxide and ytterbium oxide codoped indium gallium zirconium oxide (Tb-Yb: InGaZrO) is formed.

Wherein MO is gallium zirconium oxide, In: ga: Zr ═ 5:1:0.05mol, denoted In (5) Ga (1) Zr (0.05); in_x(GaZr)_yYb_nTb_mO_zWherein x is 0.7, y is 0.147, m is 0.103, and n is 0.05. But is not limited to the above-mentioned proportions,in other embodiments, x is 0.65, y is 0.1365, m is 0.1635, and n is 0.05, or x is 0.63, y is 0.1323, m is 0.1877, and n is 0.05, or x is 0.74, y is 0.1554, m is 0.0546, and n is 0.05, which are not described herein again.

Example 5: cerium oxide and europium oxide codoped indium zinc oxide semiconductor material

A group of metal oxide semiconductor materials, the group of metal oxide semiconductor materials being: cerium oxide is doped into indium zinc oxide (InZnO) to be used as a charge conversion center, europium oxide is doped to be used as a carrier control agent, and the semiconductor material of cerium oxide and europium oxide codoped indium zinc oxide (Ce-Eu: InZnO) is formed.

Wherein MO is zinc oxide, In: zn 9:1mol, denoted In (9) Zn (1); in_xZn_yEu_nCe_mO_zWherein x is 0.68, y is 0.0756, m is 0.1944, and n is 0.05. In other embodiments, x is 0.7, y is 0.0778, m is 0.1722, and n is 0.05, or x is 0.75, y is 0.0833, m is 0.1167, and n is 0.05, or x is 0.8, y is 0.0889, m is 0.0611, and n is 0.05, which are not repeated herein.

Example 6: dysprosium oxide and ytterbium oxide co-doped indium zinc tantalum oxide semiconductor material

A group of metal oxide semiconductor materials, the group of metal oxide semiconductor materials being: dysprosium oxide is doped into indium zinc tantalum oxide (InZnTaO) to serve as a charge conversion center, ytterbium oxide is doped to serve as a carrier control agent, and the semiconductor material of dysprosium oxide and ytterbium oxide co-doped indium zinc tantalum oxide (Dy-Yb: InZnTaO) is formed.

Wherein MO is zinc tantalum oxide, In: ta is 3:1:0.1mol, denoted In (3) Zn (1) Ta (0.1); in_x(ZnTa)_yYb_nDy_mO_zWherein x is 0.58, y is 0.2127, m is 0.1573, and n is 0.05. Without being limited to the above ratios, in other embodiments, x is 0.6, y is 0.22, m is 0.13, and n is 0.05, or, x is 0.65, y is 0.2383, m is 0.0617, and n is 0.05, or, x is 0.68, y is 0.2493, m is 0.0207, and n is 0.06170.05, which is not described in detail herein.

Example 7: praseodymium oxide and europium oxide co-doped indium tin zinc oxide film

A group of metal oxide semiconductor thin films formed from the metal oxide semiconductor thin films of example 1Praseodymium oxide and oxygen Europium-doped indium tin zinc oxideThe semiconductor material is formed by magnetron sputtering.

Example 8: praseodymium oxide and ytterbium oxide co-doped indium zinc titanium oxide film

A group of metal oxide semiconductor thin films formed by the method of example 2Praseodymium oxide and oxygen Ytterbium codoped indium zinc titanium oxideThe semiconductor material is formed by magnetron sputtering.

Example 9: terbium oxide and europium oxide co-doped indium gallium zinc oxide film

A group of metal oxide semiconductor thin films formed from the metal oxide semiconductor thin films of example 3Terbium oxide, oxygen Europium-doped indium gallium zinc oxideThe semiconductor material is prepared by magnetron sputtering.

Example 10: terbium oxide and ytterbium oxide co-doped indium gallium zirconium oxide film

A group of metal oxide semiconductor thin films formed from the metal oxide semiconductor thin films of example 4Terbium oxide, oxygen Ytterbium-codoped indium gallium zirconium oxideThe semiconductor material is prepared by magnetron sputtering.

Example 11: cerium oxide and europium oxide codoped indium zinc oxide film

A group of metal oxide semiconductor thin films formed from the metal oxide semiconductor thin films of example 5Cerium oxide, oxygen Europium-codoped indium zinc oxideThe semiconductor material is prepared by a solution method.

Example 12: dysprosium oxide and ytterbium oxide co-doped indium zinc tantalum oxide film

A set of metal oxide semiconductor films, the set of metal oxide semiconductor filmsFilm from example 6Dysprosium oxide and oxygen Ytterbium codoped indium zinc tantalum oxideThe semiconductor material is prepared by adopting a magnetron sputtering mode.

Example 13: thin film transistor

A group of thin film transistors adopts a back channel etching type structure, the structural schematic diagram of the thin film transistors is shown in figure 1, and the thin film transistors are provided with: the transistor comprises a substrate 01, a grid 05 positioned on the substrate 01, an insulating layer 04 positioned on the substrate 01 and the grid 05, a channel layer 03 covering the upper surface of the insulating layer 04 and corresponding to the grid 05, a source electrode 07-1 and a drain electrode 07-2 which are spaced from each other and electrically connected with two ends of the channel layer 03, and a spacing layer 06.

The substrate 01 is a hard alkali-free glass substrate, and is covered with a buffer layer 02 of silicon oxide.

The gate 05 is made of a metal molybdenum/copper (Mo/Cu) laminated structure prepared by a magnetron sputtering method, and has a thickness of 20/400 nm.

The insulating layer 04 is made of silicon nitride (Si) prepared by chemical vapor deposition₃N₄) And silicon oxide (SiO)₂) In which silicon nitride is in contact with the gate 05 at the lower layer and silicon oxide is in contact with the channel layer 03 at the upper layer, is 250/50nm thick.

In order to test the influence of different praseodymium oxide contents on the device performance, the channel layer 03 is made of the praseodymium oxide and europium oxide co-doped indium tin zinc oxide semiconductor material in example 1, and is prepared by using three ceramic targets, namely indium tin zinc oxide (InSnZnO), europium oxide doped indium tin zinc oxide (Eu: InSnZnO), and praseodymium oxide and europium oxide co-doped indium tin zinc oxide (Pr-Eu: insn zno), and by adjusting the sputtering power of the two targets in a single target or two co-sputtering manner, and by adjusting the sputtering power of the two targets, films with different component ratios are prepared.

The source electrode 07-1 and the drain electrode 07-2 are made of a metal molybdenum/copper (Mo/Cu) laminated structure, the thickness is 20/400nm, patterning is carried out by using a commercial hydrogen peroxide water-based etching solution, damage to the channel layer 03 is small, and no obvious etching residue exists.

The material of the spacing layer 06 is silicon oxide (SiO) prepared by chemical vapor deposition₂) The thickness of the film is 300nm,the deposition temperature was 250 ℃.

The thin film transistor of this embodiment may have a closed structure including only the substrate 01, the gate electrode 05, the insulating layer 04, the channel layer 03, the source and drain electrodes 07-1 and 07-2, and the spacer layer 06, may further include a planarization layer, a reflective electrode, a pixel defining layer, and the like, and may be integrated with other devices.

The patterning process of the film adopts a photoetching process and combines an etching mode of a wet method or a dry method.

Specific parameters and performance of the prepared thin film transistor device in the embodiment are shown in table 1, wherein the characterization mode of the photo-generated current characteristic is that a commercial white LED light source (light intensity is set to 10000nits) is adopted to irradiate a channel layer 03 of the thin film transistor device, and the intensity of the device is evaluated by evaluating the transfer characteristic of the device under the conditions of illumination and no illumination and extracting the variation conditions of the threshold voltage, the sub-threshold swing amplitude and the like of the device; the large variation amplitude of the threshold voltage indicates that the photo-generated current characteristic is strong, otherwise, the photo-generated current characteristic is weak.

TABLE 1

As can be seen from table 1, the incorporation of praseodymium oxide and europium oxide has a very significant effect on the device performance. First, as shown in test 1 of table 1, devices made of indium tin zinc oxide undoped with praseodymium oxide (m ═ 0) and europium oxide (n ═ 0) do not exhibit the "on-off" characteristics (on-state) of thin film transistors, indicating that the carrier concentration in the thin film is too high. As shown in test 2 of table 1, the device exhibited "on-off" characteristics after a certain amount of europium oxide was incorporated (corresponding to m being 0 and n being 0.05), as shown in fig. 4(a), indicating that the europium oxide incorporation was effective in suppressing the carrier concentration in the film and the corresponding film Hall data are shown in table 1. Further, as shown in experiments 2 to 8 of table 1, a series of devices with different praseodymium contents can be prepared by adjusting the sputtering power of the target in the co-sputtering. It should be noted that the praseodymium oxide-undoped device (corresponding to m being 0 and n being 0.05) has relatively high mobility, small subthreshold swing and relatively negative threshold voltage, but its photo-generated current characteristics are extremely strong, i.e. the device characteristics are changed very obviously under the condition of light irradiation (threshold voltage shifts negatively and subthreshold swing degradation is serious). However, the photoproduction current characteristic of the device is obviously inhibited after a certain amount of praseodymium oxide is doped. Of course, as the content of praseodymium oxide increases, the mobility and other characteristics of the device are further degraded, and the characteristics of the photo-generated current are further improved. When excess praseodymium oxide is doped (for example, m is 0.15, n is 0.05), the mobility of the device is obviously degraded, and although the photogenerated current characteristics of the device are extremely weak, the application field of the device is greatly limited. Therefore, in practical applications, the appropriate amount of the dopant should be selected by balancing the relationship between the two.

Corresponding photo-generated current characteristic tests are performed on the device prepared in the embodiment, as shown in fig. 4(b) and 4(c), corresponding m values are 0 and 0.05, respectively, when light irradiates on the device, the threshold voltage of the device without praseodymium oxide doping (corresponding to m being 0, n being 0.05) is obviously shifted in a negative direction, and the sub-threshold swing is seriously degraded; after a certain amount of praseodymium oxide is doped (corresponding to m being 0.05 and n being 0.05), the threshold voltage of the device is hardly changed; the light stability is excellent, namely the characteristics of weak light current generation in the table 1 are shown.

The test result of the embodiment shows that the invention can effectively control the carrier concentration of the material and improve the light stability by doping a certain amount of praseodymium oxide and europium oxide in the indium tin zinc oxide matrix material.

Example 14: thin film transistor

In order to test the influence of different ytterbium oxide contents on the device performance, the material of the channel layer 03 is the praseodymium oxide and ytterbium oxide co-doped indium zinc titanium oxide semiconductor material of embodiment 2, and the preparation of the thin film with different component ratios is realized by using three ceramic targets, namely indium zinc titanium oxide (InZnTiO), praseodymium oxide doped indium zinc titanium oxide (Pr: InZnTiO), and praseodymium oxide and ytterbium oxide co-doped indium zinc titanium oxide (Pr-Yb: InZnTiO), and by adopting a single target or a co-sputtering mode of two targets and adjusting the sputtering power of the two targets.

The material of the spacing layer 06 is silicon oxide (SiO) prepared by chemical vapor deposition₂) The thickness is 300nm, and the deposition temperature is 250 ℃.

Specific parameters and performance of the prepared thin film transistor device in the embodiment are shown in table 2, wherein the characterization mode of the photo-generated current characteristic is that a commercial white LED light source (light intensity is set to 10000nits) is adopted to irradiate a channel layer 03 of the thin film transistor device, and the intensity of the device is evaluated by evaluating the transfer characteristic of the device under the conditions of illumination and no illumination and extracting the variation conditions of the threshold voltage, the sub-threshold swing amplitude and the like of the device; the large variation amplitude of the threshold voltage indicates that the photo-generated current characteristic is strong, otherwise, the photo-generated current characteristic is weak.

TABLE 2

As can be seen from table 2, the incorporation of praseodymium oxide and ytterbium oxide had a very significant effect on device performance. First, as shown in test 1 of table 2, devices made of indium zinc titanium oxide undoped with praseodymium oxide (m ═ 0) and ytterbium oxide (n ═ 0) do not exhibit the "on-off" characteristics (on-state) of the thin film transistor, indicating that the carrier concentration in the thin film is excessively high. As shown in test 2 of table 2, the device still exhibited no "on-off" characteristics by incorporating a certain amount of praseodymium oxide (corresponding to m being 0.05 and n being 0); further, after a certain amount of ytterbium oxide is further doped (corresponding to m being 0.05 and n being 0.0001), the device shows "on-off" characteristics; the inhibition effect of praseodymium oxide on the carrier concentration in the film is shown to be less obvious than that of ytterbium oxide, and the corresponding film Hall data is shown in Table 2. In order to further study the effect of ytterbium oxide, as shown in tests 2 to 8 of table 2, a series of devices with different ytterbium contents can be prepared by adjusting the sputtering power of the target in the co-sputtering. Specifically, devices doped with a small amount of ytterbium oxide (corresponding to m 0.05 and n 0.0001) have relatively high mobility and relatively negative threshold voltages. With the increase of ytterbium oxide content, the threshold voltage of the device shifts forwards, and the mobility decreases progressively; the ytterbium oxide can effectively regulate and control the threshold voltage of the device, namely, the carrier concentration in the film, and can be further authenticated from Hall data in the table 2. Of course, after the excess ytterbium oxide is doped (for example, m is 0.05, n is 0.15), the mobility of the device is obviously degraded, which greatly limits the application field. Therefore, in practical applications, the appropriate amount of the dopant should be selected by balancing the relationship between the two.

Corresponding photo-generated current characteristic tests are performed on the device prepared in this embodiment, as shown in fig. 5(b) and 5(c), the corresponding m values are both 0.05, and the n values are 0.001 and 0.05, respectively, when light is irradiated on the device, the threshold voltage of the device doped with a small amount of ytterbium oxide (corresponding to m being 0.05, n being 0.001) does not significantly shift, and the subthreshold swing is slightly degraded; in addition, when a certain amount of ytterbium oxide was added (corresponding to m being 0.05 and n being 0.05), the threshold voltage of the device was almost unchanged, and excellent light stability, that is, corresponding to the weak light current generation characteristics in table 2, was exhibited. It should be noted that the photo-generated current characteristics of the devices with different ytterbium contents (m is 0.05, and n is 0-0.15) are weak, which indicates that the incorporation of praseodymium oxide can effectively improve the light stability of the devices.

The test result of the embodiment shows that the indium zinc oxide titanium matrix material doped with a certain amount of praseodymium oxide and ytterbium oxide can effectively control the carrier concentration of the material and improve the light stability.

Example 15: thin film transistor

A group of thin film transistors, which adopt a top gate self-aligned structure, and the schematic structural diagram of which is shown in fig. 2, is provided with: the semiconductor device comprises a substrate 01, a buffer layer 02, a channel layer 03, an insulating layer 04 and a gate 05 which are positioned on the channel layer 03, a spacer layer 06 covering the upper surfaces of the channel layer 03 and the gate, and a source electrode 07-1 and a drain electrode 07-2 which are positioned on the spacer layer 06 and are electrically connected with two ends of the channel layer 03.

The substrate 01 is a hard glass substrate.

The buffer layer 02 is silicon oxide prepared by plasma enhanced chemical vapor deposition.

The channel layer 03 is made of terbium oxide and europium oxide co-doped indium gallium zinc oxide semiconductor material in example 3, and has a thickness of 30 nm.

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

The spacer layer 06 is silicon oxide with a thickness of 300 nm.

The source electrode 07-1 and the drain electrode 07-2 are made of titanium/copper (Ti/Cu) laminated structures prepared in a magnetron sputtering mode, and the thickness of the laminated structures is 20/400 nm.

In order to test the influence of different europium contents on the device performance, the channel layer 03 is made of the terbium oxide/europium oxide-codoped indium gallium zinc oxide semiconductor material in example 3, and is prepared by using three ceramic target materials, namely indium gallium zinc oxide (InGaZnO), terbium oxide-doped indium gallium zinc oxide (Tb: InGaZnO), and terbium oxide/europium oxide-codoped indium gallium zinc oxide (Tb-Eu: InGaZnO), in a single target material or two target material co-sputtering manner and adjusting the sputtering power of the two target materials to realize the preparation of films with different component ratios.

The thin film transistor of the present embodiment may be a closed structure including only the substrate 01, the channel layer 03, the insulating layer 04, the gate 05, the spacer layer 06, the source electrode 07-1, and the drain electrode 07-2, may further include a passivation layer, a pixel defining layer, and the like, and may be integrated with other devices.

The patterning of the thin film is carried out by adopting photoetching and combining with a wet etching mode or a dry etching mode.

Specific parameters and performance of the prepared thin film transistor device in the embodiment are shown in table 3, wherein the characterization mode of the photo-generated current characteristic is that a commercial white LED light source is adopted to irradiate a channel layer of the thin film transistor device, and the intensity of the device is evaluated by characterizing the transfer characteristic of the device under different light intensity conditions and extracting the variation condition of the threshold voltage of the device; the large variation amplitude of the threshold voltage indicates that the photo-generated current characteristic is strong, otherwise, the threshold voltage is weak.

TABLE 3

From this table 3, it can be seen that the incorporation of terbium oxide and europium oxide has a very significant effect on the device performance. First, as shown in test 1 of table 3, devices made of indium gallium zinc oxide undoped with terbium oxide (m ═ 0) and europium oxide (n ═ 0) do not exhibit the "on-off" characteristics (on-state) of thin film transistors, indicating that the carrier concentration in the thin film is too high. As shown in test 2 of table 3, the device still showed no "on-off" behavior after a certain amount of terbium oxide (corresponding to m 0.05 and n 0) was incorporated; further, when a certain amount of europium oxide is further doped (corresponding to m being 0.05 and n being 0.0001), the device exhibits "switching" characteristics; the inhibition effect of terbium oxide on the carrier concentration in the film is not as obvious as that of europium oxide, and the corresponding film Hall data are shown in Table 3. In order to further study the influence of europium oxide, as shown in tests 2 to 8 in table 3, a series of devices with different europium contents can be prepared by adjusting the sputtering power of the target in the co-sputtering. Specifically, devices doped with a small amount of europium oxide (corresponding to m 0.05 and n 0.0001) have relatively high mobility and relatively negative threshold voltage. With the increase of the content of europium oxide, the threshold voltage of the device shifts in the positive direction, and the mobility decreases progressively; indicating that europium oxide can effectively regulate and control the threshold voltage of the device, that is, the carrier concentration in the film, and further authentication can be performed from Hall data in Table 3. Of course, after doping with excess europium oxide (e.g., m 0.05 and n 0.15), the mobility of the device is significantly degraded, which greatly limits the application fields. Therefore, in practical applications, the appropriate amount of the dopant should be selected by balancing the relationship between the two. Corresponding photo-generated current characteristic tests are carried out on the device prepared in the embodiment, as shown in fig. 6(b) and 6(c), corresponding m values are both 0.05, and n values are 0.001 and 0.05, respectively, when light irradiates on the device, the threshold voltage of the device doped with a small amount of europium oxide (corresponding to m being 0.05, n being 0.001) does not obviously shift, and the subthreshold swing is slightly degraded; in addition, when a certain amount of europium oxide was added (corresponding to m being 0.05 and n being 0.05), the threshold voltage of the device was almost unchanged, and excellent light stability, that is, weak light current characteristics in table 3 were exhibited. It should be noted that the photo-generated current characteristics of the devices with different europium contents (m is 0.05, and n is 0-0.15) are weak, which indicates that the incorporation of terbium oxide can effectively improve the light stability of the devices.

The test result of the embodiment shows that the invention can effectively control the carrier concentration of the material and improve the light stability by doping a certain amount of terbium oxide and europium oxide in the indium gallium zinc oxide matrix material.

Example 16: thin film transistor

The substrate 01 is a hard glass substrate.

The channel layer 03 is made of the terbium oxide and ytterbium oxide co-doped indium gallium zirconium oxide semiconductor material in example 4, and has a thickness of 30 nm.

The spacer layer 06 is silicon oxide with a thickness of 300 nm.

In order to test the influence of different terbium contents on the device performance, the channel layer 03 is made of the terbium oxide/ytterbium oxide co-doped indium gallium zirconium oxide semiconductor material in example 4, and is prepared by using three ceramic targets, namely indium gallium zirconium oxide (InGaZrO), terbium oxide-doped indium gallium zirconium oxide (Tb: InGaZrO), and terbium oxide/ytterbium oxide co-doped indium gallium zirconium oxide (Tb-Yb: InGaZrO), and adjusting the sputtering powers of the two targets by adopting a single target or two targets co-sputtering mode.

Specific parameters and performance of the prepared thin film transistor device in the embodiment are shown in table 4, wherein the characterization mode of the photo-generated current characteristic is that a commercial white LED light source is adopted to irradiate a channel layer 03 of the thin film transistor device, and the intensity of the device is evaluated by characterizing the transfer characteristic of the device under different light intensity conditions and extracting the change condition of the threshold voltage of the device; the large variation amplitude of the threshold voltage indicates that the photo-generated current characteristic is strong, otherwise, the threshold voltage is weak.

TABLE 4

From this table 4, it can be seen that the incorporation of terbium oxide and ytterbium oxide has a very significant effect on the device performance. First, as shown in test 1 of table 4, devices made of indium gallium zirconium oxide undoped with terbium oxide (m ═ 0) and ytterbium oxide (n ═ 0) do not exhibit the "on-off" characteristics (on-state) of thin film transistors, indicating that the carrier concentration in the thin film is too high. As shown in test 2 of table 4, the device exhibited "on-off" characteristics after a certain amount of ytterbium oxide (corresponding to m being 0 and n being 0.05) was incorporated, as shown in fig. 7(a), indicating that the incorporation of ytterbium oxide was effective in suppressing the carrier concentration in the film, and the corresponding film Hall data are shown in table 4. Further, as shown in tests 2 to 8 of table 4, a series of devices with different terbium contents can be prepared 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 being 0 and n being 0.05) has relatively high mobility, small subthreshold swing and relatively negative threshold voltage, but its photo-generated current characteristics are extremely strong, i.e. the device characteristics are changed very obviously under the condition of light irradiation (threshold voltage is shifted negatively, subthreshold swing is degraded severely). However, the photoproduction current characteristic of the device is obviously inhibited after a certain amount of terbium oxide is doped. Of course, as the content of terbium oxide increases, the mobility and other characteristics of the device are further degraded, and the light-generated current characteristics are further improved. When an excessive amount of terbium oxide is doped (for example, m is 0.15, n is 0.05), the mobility of the device is obviously degraded, and although the photoproduction current characteristics of the device are extremely weak, the application field of the device is greatly limited. Therefore, in practical applications, the appropriate amount of the dopant should be selected by balancing the relationship between the two.

Corresponding photo-generated current characteristic tests are performed on the device prepared in this embodiment, as shown in fig. 7(b) and 7(c), corresponding n values are both 0.05, and m values are 0 and 0.05, respectively, when light irradiates on the device, the threshold voltage of the device without terbium oxide doping (corresponding to m being 0, n being 0.05) is significantly negatively shifted, and the sub-threshold swing is severely degraded; after a certain amount of terbium oxide is doped (corresponding to m being 0.05 and n being 0.05), the threshold voltage of the device is hardly changed; the light stability is excellent, namely the characteristics of weak light current generation in the table 4 are shown.

The test result of the embodiment shows that a certain amount of terbium oxide and ytterbium oxide are doped into the indium gallium zirconium oxide matrix material, so that the carrier concentration of the material can be effectively controlled, and the light stability is improved.

Example 17: thin film transistor

A set of thin film transistors, which adopts a self-aligned structure, and the schematic structural diagram of which is shown in fig. 2, is provided with: the semiconductor device comprises a substrate 01, a buffer layer 02, a channel layer 03, an insulating layer 04 and a gate 05 which are positioned on the channel layer 03, a spacer layer 06 covering the upper surfaces of the channel layer 03 and the gate 05, and a source electrode 07-1 and a drain electrode 07-2 which are positioned on the spacer layer 06 and are electrically connected with two ends of the channel layer 03.

The substrate 01 is a hard glass substrate.

The channel layer 03 is made of the cerium oxide and europium oxide co-doped indium zinc oxide semiconductor material of example 5 and has a thickness of 20 nm.

The insulating layer 04 is made of silicon oxide and has the thickness of 300 nm; the gate 05 is a molybdenum/copper/molybdenum (Mo/Cu/Mo) laminated structure prepared by a magnetron sputtering method, and the thickness is 20/400/50 nm.

The spacing layer 06 is a silicon oxide film prepared by plasma enhanced chemical vapor deposition, and the thickness is 300 nm.

The source electrode 07-1 and the drain electrode 07-2 are made of a molybdenum/copper/molybdenum (Mo/Cu/Mo) laminated structure prepared in a magnetron sputtering mode, and the thickness is 20/400/50 nm.

Specific parameters and performance of the prepared thin film transistor device in the embodiment are shown in table 5, wherein the characterization mode of the photo-generated current characteristic is that a commercial white LED light source is adopted to irradiate a channel layer 03 of the thin film transistor device, and the intensity of the device is evaluated by representing the transfer characteristic of the device under different light intensity conditions and extracting the change condition of the threshold voltage of the device; the large variation amplitude of the threshold voltage indicates that the photo-generated current characteristic is strong, otherwise, the threshold voltage is weak.

TABLE 5

From this table 5, it can be seen that the incorporation of cerium oxide and europium oxide has a very significant effect on the device performance. First, as shown in test 1 of table 5, devices made of indium zinc oxide undoped with cerium oxide (m ═ 0) and europium oxide (n ═ 0) do not exhibit the "on-off" characteristics (on-state) of thin film transistors, indicating that the carrier concentration in the thin film is too high. As shown in test 2 of table 5, the device exhibited "on-off" characteristics after a certain amount of europium oxide was incorporated (corresponding to m being 0 and n being 0.05), as shown in fig. 8(a), indicating that the europium oxide incorporation was effective in suppressing the carrier concentration in the film and the corresponding film Hall data are shown in table 5. Further, as shown in tests 2 to 8 of table 5, a series of devices with different cerium contents can be prepared by adjusting the components in the prepared solution. It should be noted that the device without doped ceria (corresponding to m being 0 and n being 0.05) has relatively high mobility, small subthreshold swing and relatively negative threshold voltage, but its photo-generated current characteristics are extremely strong, i.e. the device characteristics are changed very obviously under the condition of light irradiation (threshold voltage is shifted negatively, subthreshold swing is degraded severely). However, the photogenerated current characteristics of the device are obviously inhibited after a certain amount of cerium oxide is doped. Of course, as the content of cerium oxide increases, the mobility and other characteristics of the device are further degraded, and the photogeneration current characteristics are further improved. When an excessive amount of cerium oxide is doped (for example, m is 0.15, n is 0.05), the mobility of the device is significantly degraded, and although the photogenerated current characteristics of the device are extremely weak, the application field is greatly limited. Therefore, in practical applications, the appropriate amount of the dopant should be selected by balancing the relationship between the two.

Corresponding photo-generated current characteristic tests are performed on the device prepared in this embodiment, as shown in fig. 8(b) and 8(c), corresponding n values are both 0.05, m values are 0 and 0.05, respectively, when light is irradiated on the device, the threshold voltage of the device without doped cerium oxide (corresponding to m being 0, n being 0.05) is significantly negatively shifted, and the sub-threshold swing is severely degraded; after a certain amount of cerium oxide is doped (corresponding to m being 0.05 and n being 0.05), the threshold voltage of the device is hardly changed; the light stability is excellent, namely the characteristics of weak light current generation in the table 5 are shown.

The test results of this example show that the doping of a certain amount of cerium oxide and europium oxide in the indium zinc oxide matrix material of the present invention can effectively control the carrier concentration of the material and improve the light stability.

Example 18: thin film transistor

A group of thin film transistors adopt an etching barrier type structure, the structural schematic diagram of which is shown in figure 3, and the thin film transistors are provided with: the semiconductor device comprises a substrate 01, a grid 05 positioned on the substrate 01, an insulating layer 04 positioned on the substrate 01 and the grid 05, a channel layer 03 covering the upper surface of the insulating layer 04 and corresponding to the grid 05, an etching barrier layer 08, a source electrode 07-1 and a drain electrode 07-2 which are mutually spaced and electrically connected with two ends of the channel layer 03, and a spacing layer 06.

The substrate 01 is a glass substrate, and a buffer layer 02 of silicon oxide is covered on the substrate.

The gate 05 is made of a molybdenum-aluminum-molybdenum (Mo/Al/Mo) metal laminated structure prepared in a magnetron sputtering mode, and the thickness of the gate is 50/300/50 nm.

The insulating layer 04 is made of silicon nitride (Si) prepared by chemical vapor deposition₃N₄) And silicon oxide (SiO)₂) 250/50nm in thickness; wherein silicon nitride contacts the gate electrode 05 at the lower layer and silicon oxide contacts the channel layer 03 at the upper layer.

In order to test the influence of different dysprosium oxide contents on the device performance, the channel layer 03 is made of the dysprosium oxide and ytterbium oxide co-doped indium zinc tantalum oxide semiconductor material of example 6, and is prepared by using three ceramic targets, namely indium zinc tantalum oxide (inZnTaO), ytterbium oxide doped indium zinc tantalum oxide (Yb: inZnTaO) and dysprosium oxide and ytterbium oxide co-doped indium zinc tantalum oxide (Dy-Yb: inZnTaO), and adjusting the sputtering power of the two targets by adopting a single target or two co-sputtering modes to prepare films with different component ratios.

The material of the etching barrier layer 08 and the spacing layer 06 is silicon oxide (SiO) prepared by a chemical vapor deposition mode₂) The thickness of the film is 300nm, and the deposition temperature is 300 ℃.

The source electrode 07-1 and the drain electrode 07-2 are made of metal molybdenum aluminum molybdenum (Mo/Al/Mo) laminated structures and have the thickness of 50/300/50 nm.

In addition, the thin film transistor of the present embodiment may have a closed structure including only the substrate 01, the gate electrode 05, the insulating layer 04, the channel layer 03, the etch stopper layer 08, the source electrode 07-1, the drain electrode 07-2, and the passivation layer, may further include a planarization layer, a reflective electrode, a pixel defining layer, and the like, and may be integrated with other devices.

Specific parameters and performance of the prepared thin film transistor device in the embodiment are shown in table 6, wherein the characterization mode of the photo-generated current characteristic is that a commercial white LED light source is adopted to irradiate a channel layer 03 of the thin film transistor device, and the intensity of the device is evaluated by evaluating the transfer characteristic of the device under the conditions of illumination and no illumination and extracting the change condition of the threshold voltage of the device; the large variation amplitude of the threshold voltage indicates that the photo-generated current characteristic is strong, otherwise, the photo-generated current characteristic is weak.

TABLE 6

From this table 6, it is understood that the incorporation of dysprosium oxide and ytterbium oxide has a very significant effect on device performance. First, as shown in test 1 of table 6, devices made of indium zinc tantalum oxide not doped with dysprosium oxide (m ═ 0) and ytterbium oxide (n ═ 0) do not exhibit the "on-off" characteristics (on-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, the device exhibited "on-off" characteristics after a certain amount of ytterbium oxide (corresponding to m being 0 and n being 0.05) was incorporated, as shown in fig. 9(a), indicating that the incorporation of ytterbium oxide was effective in suppressing the carrier concentration in the film, and the corresponding film Hall data is shown in table 6. Further, as shown in experiments 2 to 8 of table 6, a series of devices with different dysprosium contents can be prepared by adjusting the sputtering power of the corresponding target. It should be noted that the device without doped dysprosium oxide (corresponding to m being 0 and n being 0.05) has relatively high mobility, small subthreshold swing and relatively negative threshold voltage, but its photogenerated current characteristics are extremely strong, i.e. the device characteristics are changed very obviously under the condition of light irradiation (threshold voltage shifts negatively and subthreshold swing degradation is serious). However, the photoproduction current characteristic of the device is obviously inhibited after a certain amount of dysprosium oxide is doped. Of course, as the content of dysprosium oxide increases, the mobility and other characteristics of the device are further degraded, and the photogeneration current characteristics are further improved. When an excessive amount of dysprosium oxide is doped (for example, m is 0.15, n is 0.05), the mobility of the device is obviously degraded, and although the photogenerated current characteristics of the device are extremely weak, the application field of the device is greatly limited. Therefore, in practical applications, the appropriate amount of the dopant should be selected by balancing the relationship between the two.

Corresponding photo-generated current characteristic tests are performed on the device prepared in this embodiment, as shown in fig. 9(b) and 9(c), corresponding n values are both 0.05, m values are 0 and 0.05, respectively, when light irradiates on the device, the threshold voltage of the device without doped dysprosium oxide (corresponding to m being 0, n being 0.05) is obviously shifted in the negative direction, and the sub-threshold swing is seriously degraded; after a certain amount of dysprosium oxide is doped (corresponding to m being 0.05 and n being 0.05), the threshold voltage of the device is hardly changed; the light stability is excellent, namely the characteristics of weak light current generation in the corresponding table 6 are shown.

The test results of the embodiment show that the indium zinc tantalum oxide base material doped with a certain amount of dysprosium oxide and ytterbium oxide can effectively control the carrier concentration of the material and improve the light stability.

Example 19: display panel

A display panel comprising the thin film transistors in embodiments 13 to 18 described above, the thin film transistors being used to drive display cells in the display panel.

Example 20: detector

A sensor comprising the thin film transistors of the above embodiments 13 to 18, the thin film transistors being used to drive the sensing units of the sensor.

Next, each functional layer of the thin film transistor according to the present invention will be described further.

The substrate in the present invention is not particularly limited, and a substrate 01 known in the art may be used. Such as: hard alkali glass, alkali-free glass, quartz glass, silicon substrate, and the like; the flexible Polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), Polyethylene (PE), polypropylene (PP), Polystyrene (PS), Polyaluminium Ether (PEs), or metal foil may be used.

The material of the gate electrode 05 in the present invention is not particularly limited, and may be arbitrarily selected from materials 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 alloys thereof, and composite conductive films formed by stacking metals and oxides (ITO/Ag/ITO, IZO/Ag/IZO, etc.), metals and metals (Mo/Al/Mo, Ti/Al/Ti, etc.).

The method for preparing the gate 05 film may be a sputtering method, electroplating, thermal evaporation, or other deposition method, and a sputtering deposition method is preferable because the film prepared by the method has good adhesion to the substrate 01, excellent uniformity, and can be prepared in a large area.

The specific structure of the gate electrode is determined according to the required technical parameters, for example, a transparent electrode is required in the transparent display, and a single layer of ITO or ITO/Ag/ITO can be used as the gate electrode. In addition, high temperature processes are required for specific applications, and the gate electrode may be selected from metal alloy films that can withstand high temperatures.

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

It is to be noted that the composition of these insulating films may not be in accordance with the theoretical stoichiometric ratio. In addition, the insulating layer 04 may be formed by stacking a plurality of insulating films, which may improve the insulating property and the interface property between the channel layer 03 and the insulating layer 04. Moreover, the insulating layer 04 can be prepared in various ways, such as physical vapor deposition, chemical vapor deposition, atomic layer deposition, laser deposition, anodic oxidation, or solution method.

The etching liquid adopted by the wet etching comprises: a mixed solution of phosphoric acid, nitric acid and glacial acetic acid or a mixed solution based on hydrogen peroxide. The etching rate of the metal oxide semiconductor material in the hydrogen peroxide water-based etching liquid is less than 1 nm/min. Dry etching illustratively, a plasma etching process may be selected, the etching gas comprising a chlorine-based or fluorine-based gas.

In the process of adopting the vacuum magnetron sputtering technology for the metal oxide semiconductor material, single-target sputtering or multi-target co-sputtering can be selected, and single-target sputtering is preferred.

Because single target sputtering can provide a film with better repeatability and more stability, and the microstructure of the film is easier to control; so as not to interfere with the recombination process of the sputtered particles by more factors like in the co-sputtered film.

In the vacuum sputtering deposition process, the power source can be selected from Radio Frequency (RF) sputtering, Direct Current (DC) sputtering or Alternating Current (AC) sputtering, and alternating current sputtering is preferred.

In the sputtering deposition process, the sputtering pressure is 0.1 Pa-10 Pa, preferably 0.3 Pa-0.7 Pa.

When the sputtering pressure is too low, stable glow sputtering cannot be maintained; when the sputtering pressure is too high, scattering of sputtered particles in the process of depositing the sputtered particles on the substrate 01 is obviously increased, energy loss is increased, kinetic energy is reduced after the sputtered particles reach the substrate 01, and defects of a formed film are increased, so that the performance of a device is seriously influenced.

In the sputtering deposition process, the oxygen partial pressure is 0-1 Pa, preferably 0.001-0.5 Pa, and more preferably 0.01-0.1 Pa.

Generally, in the process of preparing an oxide semiconductor by sputtering, the oxygen partial pressure has a direct influence on the carrier concentration of a thin film and some oxygen vacancy related defects are introduced. Too low oxygen content may cause severe oxygen mismatch in the film and increase carrier concentration; too high oxygen vacancies, in turn, can cause more weak bonding bonds, reducing the reliability of the device.

In the sputtering deposition process, the substrate temperature is preferably 200-300 ℃.

In the process of channel layer film deposition, the combination mode of sputtered particles after reaching the substrate 01 can be effectively improved at a certain substrate temperature, the existence probability of weak combination bonds is reduced, and the stability of the device is improved. Of course, the same effect can be achieved by subsequent annealing processes.

The thickness of the channel layer 03 is 2-100 nm, preferably 5-50 nm, and more preferably 20-40 nm.

The source and drain electrode material in the present invention is not particularly limited, and may be arbitrarily selected from materials known in the art without affecting the realization of various devices having desired structures. Such as: transparent conductive oxides (ITO, AZO, GZO, IZO, ITZO, FTO, etc.), metals (Mo, Al, Cu, Ag, Ti, Au, Ta, Cr, Ni, etc.) and alloys thereof, and composite conductive films formed by stacking metals and oxides (ITO/Ag/ITO, IZO/Ag/IZO, etc.), metals and metals (Mo/Al/Mo, Ti/Al/Ti, etc.).

The preparation method of the source and drain electrode film can be a sputtering method, thermal evaporation and other deposition modes, and a sputtering deposition mode is preferred because the film prepared by the method has good adhesion with the substrate 01, excellent uniformity and large-area preparation.

Here, it should be particularly noted that, in the preparation of a device with a back channel etching type structure, the source-drain electrode and the channel layer 03 need to have a proper etching selection ratio, otherwise, the preparation of the device cannot be realized. The etching solution for wet etching in the embodiment of the invention is based on the etching solution (such as hydrogen peroxide water-based etching solution) of the conventional metal in the industry, mainly because the metal oxide semiconductor material can effectively resist the etching of the hydrogen peroxide water-based etching solution in the wet method, the metal oxide semiconductor material and the metal (such as molybdenum, molybdenum alloy, molybdenum/aluminum/molybdenum and the like) have high etching selection ratio, the metal oxide semiconductor layer is basically not influenced by the etching solution, and the prepared device has excellent performance and good stability. In addition, the dry etching in the embodiment of the present invention is based on etching gases (such as chlorine-based gas, fluorine-based gas, and the like) which are conventional in the industry, and has little influence on the oxide semiconductor layer of the present invention, and the prepared device has excellent performance and good stability.

The material of the passivation layer in the present invention is not particularly limited, and may be arbitrarily selected from materials known in the art. Such as: silicon oxide, silicon nitride, aluminum oxide, tantalum oxide, hafnium oxide, yttrium oxide, and a polymer organic film layer.

It is to be noted that the composition of these insulating films may not be in accordance with the theoretical stoichiometric ratio. In addition, the insulating layer 04 may be formed by stacking a plurality of insulating films, which may improve the insulating property and the interface property between the channel layer 03 and the passivation layer. Moreover, the passivation layer can be prepared in various ways, such as physical vapor deposition, chemical vapor deposition, atomic layer deposition, laser deposition or solution method.

Next, a processing process in the thin film transistor manufacturing process according to the embodiment of the present invention will be further described.

In contrast, the speed of the deposited film is generally higher due to the participation of high-energy plasma in the film prepared by sputtering; the film does not have enough time to undergo a relaxation process during deposition, which can cause a proportion of dislocations and stresses to remain in the film. This requires a post heat anneal process to continue to achieve the desired relatively steady state, improving the film properties.

In the practice of the present invention, the anneal process is mostly provided after the deposition of the channel layer 03, and after the deposition of the passivation layer. On one hand, annealing treatment is carried out after the channel layer 03 is deposited, so that in-situ defects in the channel layer 03 can be effectively improved, and the capability of the channel layer 03 in resisting possible damage in the subsequent process is improved. On the other hand, during the subsequent deposition of the passivation layer, due to the participation of plasma and the modification of active groups, this may require an "activation" process to further eliminate the effects of interface states and some donor doping.

Additionally, in the practice of the present invention, the treatment may be performed in a manner other than just a heat treatment, and may include plasma treatment of the interface (e.g., insulating layer 04/semiconductor interface, channel layer 03/passivation layer interface, etc.).

The performance of the device can be effectively improved and the stability of the device can be improved through the treatment process.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A metal oxide semiconductor is characterized in that the metal oxide semiconductor is as follows: in a metal oxide MO-In containing indium₂O₃In is formed by doping at least two kinds of rare earth element R oxide and rare earth element R' oxide, respectively_xM_yR_nR’_mO_zThe semiconductor material is characterized in that x + y + m + n is 1, x is more than or equal to 0.4 and less than 0.9999, y is more than or equal to 0 and less than 0.5, m is more than or equal to 0.0001 and less than or equal to 0.2, n is more than 0, and z is more than 0.

2. The metal oxide semiconductor according to claim 1, wherein the oxide of the rare earth element R is a carrier concentration control agent.

3. The metal oxide semiconductor according to claim 1, wherein the oxide of the rare earth element R is one or a combination of two materials selected from ytterbium oxide and europium oxide.

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

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

6. The metal oxide semiconductor according to claim 1, wherein 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.

7. The metal oxide semiconductor according to any one of claims 1 to 6, wherein the metal oxide semiconductor is formed into a film 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 process.

8. A thin film transistor comprising a gate electrode, an active layer, an insulating layer 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 any one of claims 1 to 6.

9. The thin film transistor of claim 8, wherein the spacer layer is one of a silicon oxide, a silicon nitride, and a silicon oxynitride film formed by plasma enhanced chemical vapor deposition, or a stacked structure of any two or more of the above.

10. Use of the thin film transistor of claim 8 in a display panel or a detector.