A flexible transparent oxide thin film transistor and a method of manufacturing the same

Abstract

The application discloses a flexible transparent oxide thin film transistor and a preparation method thereof. The flexible transparent oxide thin film transistor is composed of a flexible substrate, a gate electrode, a gate dielectric layer, a channel layer and a source electrode and a drain electrode which are sequentially stacked, the channel layer is a homogenous double-channel structure with high carrier concentration and low carrier concentration, the high carrier concentration channel layer is located on one side of the gate dielectric layer, and the low carrier concentration channel layer is located on one side of the source electrode and the drain electrode; the gate electrode, the gate dielectric layer, the channel layer, the source electrode and the drain electrode are prepared by using an atomic layer deposition technology, and do not need annealing treatment, so that the interface state quality can be improved, and the flexible transparent oxide thin film transistor with high performance can be prepared.

Description

Technical Field

[0001] This invention belongs to the field of thin-film transistor technology, specifically relating to a flexible transparent oxide thin-film transistor and its fabrication method. Background Technology

[0002] In recent years, flexible electronics technology has attracted widespread attention due to its excellent flexibility, portability, low processing cost, and large-area manufacturing capabilities, showing great application potential in information fields such as flexible displays, smart wearables, and medical electronics. The key to this technology lies in how to directly fabricate thin-film transistors onto flexible substrates. This requires minimizing the fabrication temperature during the preparation of thin-film transistor devices. The main technical challenge lies in how to reduce interface state defects and improve interface quality under low-temperature conditions. Summary of the Invention

[0003] This invention is made to solve the above-mentioned problems and aims to provide a low-temperature fabrication process for high-performance oxide thin-film transistors. The entire thin-film fabrication process adopts atomic layer deposition technology. By setting a homogeneous dual-channel structure, no subsequent annealing treatment is required. It has low interface state defects and high interface quality, which can meet the fabrication process requirements of flexible and biocompatible thin-film transistors and has great application value in the field of flexible displays.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A flexible transparent oxide thin-film transistor comprises a flexible substrate, a gate, a gate dielectric layer, a channel layer, a source, and a drain, which are stacked sequentially. The channel layer is a homogeneous dual-channel structure with high carrier concentration and low carrier concentration, wherein the high carrier concentration channel layer is located on the gate dielectric layer side, and the low carrier concentration channel layer is located on the source and drain side. The gate, gate dielectric layer, channel layer, source, and drain are all fabricated using atomic layer deposition technology, and no annealing process is required throughout the process.

[0006] Furthermore, the gate material is any one of AZO, IZO, GZO, and ITO.

[0007] Furthermore, the material of the gate dielectric layer is one or a mixture of at least two of SiO2, Al2O3, HfO2, ZrO2, and TiO2.

[0008] Furthermore, the channel layer is made of Ga2O3-based metal oxide and is not doped with Zn.

[0009] Furthermore, the carrier concentration of the channel layer can be changed by doping with In or Sn elements and adjusting the In or Sn doping ratio.

[0010] Furthermore, the high carrier concentration channel layer is doped with a high proportion of In or Sn, and the low carrier concentration channel layer is doped with a low proportion of In or Sn.

[0011] Furthermore, the source and drain are any one of AZO, IZO, GZO, and ITO.

[0012] The method for fabricating the above-mentioned flexible transparent oxide thin-film transistor includes the following steps:

[0013] Step 1. First, spin-coat a layer of organic solution onto the rigid substrate, and then attach the flexible substrate onto the rigid substrate;

[0014] Step 2. Then, the gate is fabricated on the flexible substrate using atomic layer deposition technology;

[0015] Step 3. The gate dielectric layer and the channel layer are prepared sequentially by atomic layer deposition. The channel layer is a homogeneous dual-channel structure with high carrier concentration and low carrier concentration. First, the high carrier concentration channel layer is deposited, and then the low carrier concentration channel layer is deposited.

[0016] Step 4. Finally, the source and drain electrodes are fabricated using atomic layer deposition (ALD) technology. After peeling off the hard substrate, a flexible transparent oxide thin-film transistor is obtained.

[0017] Compared with the prior art, the thin-film transistor of the present invention has the following beneficial technical effects:

[0018] This invention provides a method that uses atomic layer deposition technology throughout the entire process. By setting up a homogeneous dual-channel structure, it eliminates the need for subsequent annealing, improves the interface state quality, enhances the performance of thin-film transistors, and solves the problem of high-temperature annealing damaging flexible substrates. This method can be fully transferred to flexible display applications.

[0019] This invention enables the fabrication of high-performance flexible transparent thin-film transistors at low temperatures. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the structure of the oxide thin-film transistor before the hard substrate is removed in this invention.

[0021] Figure 2 is a schematic diagram of the structure of the flexible transparent oxide thin film transistor prepared after the hard substrate is peeled off according to the present invention.

[0022] 1: Rigid substrate; 2: Flexible substrate; 3: Gate; 4: Gate dielectric layer; 5: High carrier concentration channel layer; 6: Low carrier concentration channel layer; 7: Channel layer; 8: Source; 9: Drain. Detailed Implementation

[0023] The following detailed description, in conjunction with the accompanying drawings, illustrates a specific embodiment of a flexible transparent oxide thin-film transistor and its fabrication method, which are based on the present invention. Example

[0024] A flexible transparent oxide thin-film transistor according to this embodiment has the following structural schematic diagram. Figure 2 As shown, the structure comprises a flexible substrate 2, a gate 3, a gate dielectric layer 4, a high carrier concentration channel layer 5, a low carrier concentration channel layer 6, a source 8, and a drain 9, stacked sequentially. The gate 3 is made of any one of AZO, IZO, GZO, and ITO. The gate dielectric layer 4 is made of one or more of SiO2, Al2O3, HfO2, ZrO2, and TiO2. The channel layer 7 is made of Ga2O3-based metal oxide. The carrier concentration of the channel layer 7 is changed by doping with In or Sn elements and adjusting the In or Sn doping ratio. The high carrier concentration channel layer 5 uses a high proportion of In or Sn doping, while the low carrier concentration channel layer 6 uses a low proportion of In or Sn doping. Typically, the channel layer of an oxide thin-film transistor is made of InGaZnO (IGZO), where Zn acts as an amorphous phase stabilizer. However, the channel layer 7 of this invention does not introduce Zn, which can lower the crystallization temperature of the thin film and is suitable for the fabrication of flexible electronic devices. Source 8 and drain 9 can be any one of AZO, IZO, GZO, or ITO.

[0025] The gate electrode 3, gate dielectric layer 4, high carrier concentration channel layer 5, low carrier concentration channel layer 6, source electrode 8, and drain electrode 9 are all fabricated using atomic layer deposition (ALD) technology, and no annealing is required throughout the process. The device is fabricated on a flexible substrate, and the specific steps are as follows: Figure 1 , 2 As shown, the flexible transparent oxide thin-film transistor of this embodiment is prepared by the following method:

[0026] Step 1. First, spin-coat a layer of organic solution onto the rigid substrate 1, and then attach the flexible substrate 2 onto the rigid substrate 1;

[0027] Step 2. Then, the gate electrode 3 is fabricated on the flexible substrate 2 using atomic layer deposition technology;

[0028] Step 3. Prepare the gate dielectric layer 4 by atomic layer deposition, and then deposit the channel layer 7. The channel layer is a homogeneous dual-channel structure with high carrier concentration and low carrier concentration. First deposit the high carrier concentration channel layer 5, and then deposit the low carrier concentration channel layer 6.

[0029] Step 4. Source 8 and drain 9 are prepared by atomic layer deposition. After peeling off the hard substrate 1, a flexible transparent oxide thin film transistor is obtained.

[0030] The above embodiments are merely illustrative examples of the technical solutions of the present invention. The flexible transparent oxide thin-film transistor and its fabrication method involved in the present invention are not limited to the contents described in the above embodiments, but are subject to the scope defined by the claims. Any modifications, additions, or equivalent substitutions made by those skilled in the art based on these embodiments are within the scope of protection claimed by the claims of the present invention.

Claims

1. A flexible transparent oxide thin-film transistor, comprising a flexible substrate, a gate, a gate dielectric layer, a channel layer, and a source and a drain layer stacked sequentially, characterized in that: The channel layer is a homogeneous dual-channel structure with high carrier concentration and low carrier concentration. The high carrier concentration channel layer is located on the gate dielectric layer side, and the low carrier concentration channel layer is located on the source and drain side. The gate, gate dielectric layer, channel layer, source and drain are all fabricated using atomic layer deposition technology, and no annealing is required throughout the process.

2. The flexible transparent oxide thin-film transistor according to claim 1, characterized in that: The gate material is any one of AZO, IZO, GZO, and ITO.

3. The flexible transparent oxide thin-film transistor according to claim 2, characterized in that: The material of the gate dielectric layer is one or more of SiO2, Al2O3, HfO2, ZrO2, and TiO2.

4. The flexible transparent oxide thin-film transistor according to claim 1, characterized in that: The channel layer is made of Ga2O3-based metal oxide and is not doped with Zn.

5. The flexible transparent oxide thin-film transistor according to claim 4, characterized in that: The carrier concentration of the channel layer can be changed by doping it with In or Sn elements and adjusting the In or Sn doping ratio.

6. The flexible transparent oxide thin-film transistor according to claim 5, characterized in that: The high carrier concentration channel layer is doped with a high proportion of In or Sn, and the low carrier concentration channel layer is doped with a low proportion of In or Sn.

7. The flexible transparent oxide thin-film transistor according to claim 6, characterized in that: The source and drain are any one of AZO, IZO, GZO, and ITO.

8. The method for fabricating the flexible transparent oxide thin-film transistor according to any one of claims 1-7, characterized in that: Step 1. First, spin-coat a layer of organic solution onto the rigid substrate, and then attach the flexible substrate onto the rigid substrate; Step 2. Then, the gate is fabricated on the flexible substrate using atomic layer deposition technology; Step 3. The gate dielectric layer and the channel layer are prepared sequentially by atomic layer deposition. The channel layer is a homogeneous dual-channel structure with high carrier concentration and low carrier concentration. First, the high carrier concentration channel layer is deposited, and then the low carrier concentration channel layer is deposited. Step 4. Finally, the source and drain electrodes are fabricated using atomic layer deposition technology, and the flexible transparent oxide thin film transistor is obtained after peeling off the hard substrate.

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