KR-20260066853-A - Method for Forming Amorphous Tellurium Oxide with Ultraviolet-Ozone Treatment, Amorphous Tellurium Oxide Formed Thereby and Field-Effect Transistor Comprising Same

Abstract

The present invention relates to a method for forming amorphous tellurium oxide through ultraviolet-ozone (UV- O3 ) treatment, an amorphous tellurium oxide formed using the same, and a field-effect transistor including the same. In the present invention, amorphous tellurium oxide (TeO x ) can be produced by ultraviolet-ozone treatment of crystalline tellurium (Te). According to the present invention, the limitations of crystalline tellurium with conventional metalloid properties can be overcome by a simple method, and a phase transition can be induced in tellurium to improve the band gap. By utilizing this, a stable high-performance field-effect transistor (FET) with high switching ratio and mobility can be manufactured.

Inventors

• 정문석
• 방승호
• 이채원
• 박대영

Assignees

• 한양대학교 산학협력단

Dates

Publication Date

20260512

Application Date

20241105

Claims (12)

1. A method for forming amorphous tellurium oxide, wherein the amorphous tellurium oxide is formed by inducing a phase transition through a UV- ozone (UV- O3 ) treatment step in which ultraviolet (UV) rays are irradiated onto a crystalline tellurium material to generate ozone (O3).
2. In Article 1, A method for forming amorphous tellurium oxide, wherein the above-mentioned ultraviolet-ozone treatment step is performed by irradiating with a light source including a wavelength range of 100 to 300 nm.
3. In Article 2, A method for forming amorphous tellurium oxide, wherein the light source comprises a wavelength range of 100 to 200 nm and a wavelength range of 220 to 300 nm.
4. In Article 1, The phase transition through the above UV-ozone treatment step, A step in which oxygen molecules ( O₂ ) are decomposed into oxygen atoms (O) by light source energy including a wavelength range of 100 to 200 nm; A step in which the above oxygen atom (O) combines with an oxygen molecule ( O2 ) to form ozone ( O3 ); A step in which the ozone ( O3 ) is decomposed into oxygen molecules ( O2 ) and oxygen radicals (O*) by light source energy including a wavelength range of 220 to 300 nm; and A step in which tellurium ionized by the above oxygen radical (O*) and light source reacts to form tellurium oxide. A method for forming amorphous tellurium oxide, performed through
5. In Article 1, The above UV-ozone treatment step, A method for forming amorphous tellurium oxide, performed using an ultraviolet ozone generator comprising a power supply, a low-pressure mercury vapor discharge lamp, a sample tray, and a sealed chamber.
6. In Article 1, A method for forming amorphous tellurium oxide, wherein the above-described UV-ozone treatment step is performed for 5 to 60 minutes.
7. In Article 1, A method for forming amorphous tellurium oxide in which the bandgap energy (E g ) of the formed amorphous tellurium oxide is 1 eV or more.
8. In Article 1, A method for forming amorphous tellurium oxide, wherein the mobility of the formed amorphous tellurium oxide is 100 cm² /V·s or higher.
9. Amorphous tellurium oxide formed by the method of any one of claims 1 to 8.
10. A field-effect transistor comprising the amorphous tellurium oxide of claim 9.
11. In Article 10, The above field-effect transistor, lower electrode, A gate insulating film formed on the lower electrode above, An amorphous tellurium oxide thin film formed on the gate insulating film, and Upper electrode formed on the above amorphous tellurium oxide thin film A field-effect transistor including
12. In Article 10, A field-effect transistor having an on/off ratio of 10³ or greater.

Description

Method for Forming Amorphous Tellurium Oxide with Ultraviolet-Ozone Treatment, Amorphous Tellurium Oxide Formed Thereby and Field-Effect Transistor Comprising Same The present invention relates to a method for forming amorphous tellurium oxide through ultraviolet-ozone (UV- O3 ) treatment, an amorphous tellurium oxide formed using the same, and a field-effect transistor including the same. More specifically, the invention relates to a method for forming amorphous tellurium oxide with excellent electrical properties in a simple manner by inducing a phase transition in two-dimensional tellurium through ultraviolet-ozone treatment, an amorphous tellurium oxide formed using the same, and a field-effect transistor including the same. A transistor is a device that uses semiconductors to amplify or switch electronic signals and power, and is widely used in various electronic devices such as displays and speakers. Conventional transistors generally used silicon-based semiconductors, but there were limitations such as the need for high-temperature heat treatment during manufacturing, difficulty in applying to 3D semiconductor technology, and low mobility. Oxide semiconductors have been proposed as one of the alternatives to silicon-based semiconductors, and oxide semiconductors have advantages in that they have high visible light transmittance, a wide bandgap, and high mobility. However, most oxide semiconductors have n-type characteristics, and p-type oxide semiconductors with a wide bandgap have limitations in that it is difficult to obtain uniform quality and electrical characteristics such as mobility and switching ratio are poor. In this regard, Korean Patent Publication No. 10-2015-0108168 describes a method for fabricating p-type oxide semiconductors by additionally combining Ga with CuS, SnO, ITO, IZTO, IGZO, IZO, etc., but there were limitations in actual process application because a heat treatment process at a high temperature of 300°C or higher is required to achieve high mobility. Meanwhile, two-dimensional (2D) semiconductors have the advantage of exhibiting excellent gate control characteristics at atomic layer thickness and improving p-type transistor performance, and research is being conducted using tellurium as a material for two-dimensional p-type semiconductors. Two-dimensional tellurium (2D-Te) has advantages in terms of high mobility and excellent stability, but it has disadvantages such as a narrow bandgap energy, a low on/off ratio, and semi-metallic characteristics. To overcome these drawbacks, reducing the thickness of 2D tellurium can expand the bandgap and improve the switching ratio, but this can lead to a decrease in mobility and has limitations such as demanding or complex process conditions. For example, the literature [Chunsong Zhao et al. , Nature Nanotechnology , volume 15, pages 53-58 (2020)] proposed a technique using thermal evaporation to deposit ultrathin tellurium films on various substrates, but this technique had the disadvantage of requiring an ultra-low temperature of -80°C. Therefore, there is a need for the development of technology that can fabricate high-performance p-type semiconductors by expanding the bandgap and improving the on/off ratio while maintaining the stability and mobility of tellurium through a simple process. FIG. 1 schematically illustrates the process of forming amorphous tellurium oxide according to one embodiment of the present invention. FIG. 2 schematically shows the structure of a device used for ultraviolet-ozone treatment in an amorphous tellurium oxide formation process according to one embodiment of the present invention. FIG. 3 schematically illustrates an ultraviolet-ozone treatment process according to one embodiment of the present invention. Figures 4a and 4b respectively show transmission electron microscope (TEM) images of crystalline tellurium (a) before UV-ozone treatment and amorphous tellurium oxide (b) after UV-ozone treatment according to one embodiment of the present invention. Figures 5a and 5b respectively show X-ray photoelectron spectroscopy (XPS) data of crystalline tellurium (a) before UV-ozone treatment and amorphous tellurium oxide (b) after UV-ozone treatment according to one embodiment of the present invention. Figure 6 shows optical microscope and atomic force microscope images of tellurium according to the UV-ozone treatment time in one embodiment of the present invention. Figure 7 shows the results of Raman spectroscopy of amorphous tellurium oxide after UV-ozone treatment in one embodiment of the present invention. FIGS. 8a and 8b show the results of measuring the field-effect mobility (μ eff ) at a temperature of 100 to 370 K for a FET device (a) using 2D Te and a FET device (b) using a- TeO3 according to one embodiment of the present invention, respectively. Figure 9 shows the SBH measurement results according to the gate voltage in an FET device using 2D Te or a- TeO3 according to one embodiment of the present