| In recent years,one-dimensional(1D)nanostructures have received widespread attention due to their characteristic physical and chemical properties,outstanding transmission characteristics,large specific surface area and good stability.1D metal oxide nanomaterials represented by In2O3 have been widely used as channel layer materials for field effect transistors(FET).At the same time,using a gate dielectric material with a high dielectric constant instead of Si O2 can not only improve the electrical performance of the FET device,but also reduce the driving voltage and power consumption of the FET device.In this thesis,indium-based nanofibers were prepared by a simple and effective electrospinning process and the high-k gate dielectric thin film was deposited by ALD process.The high-performance FET device with low voltage operation was successfully constructed.Besides,a load-type inverter was constructed based on the FET device and its static voltage characteristics and dynamic response behavior were investigated.The specific research content of this paper is divided into the following three parts:1.In2O3 nanofibers were fabricated by electrospinning technology,and their optical properties,microstructure,surface morphology and chemical composition were analyzed.By modulatingthe electrospinning time,In2O3/Si O2 FETs with different nanofiber density were constrcted and their properties were explored.The results show that when the spinning time is30s,the In2O3/Si O2FET exhibits excellent electrical properties,including a mobility of 9.1cm2 V-1 s-1 and a current-on-off ratio of 1.0×107.The high-k gate dielectric Al2O3 was deposited by ALD instead of traditional Si O2,and the operating voltage of the device was reduced from 30 V to 3 V.The built-up load inverter gain reached 9.8,which indicated the ALD-deirved Al2O3thin film had attractive application prospects in the fieil of low-voltage drives FET and inverter.2.Based on the Ca-doped In2O3 nanofibers fabricated by the electrospinning method,the effects of different concentrations of Ca on the optical properties,microstructure,surface morphology and chemical composition of the nanofibers were investigated.In Ca Ox/Si O2 FET device testing shows that when the Ca doping concentration is 5 mol%,the FET exhibits the best performance,including a mobility of 6.5 cm2 V-1 s-1 and a current-on-off ratio of 1.0×108.The voltage gain of the inverter constructed in series with In Ca Ox/Si O2 FET and load-type resistor reaches 7.2,which is sufficient for signal propagation in integrated circuits.3.The HfAlOx gate dielectric film was fabricated at low temperature based on ALD technology.The optical properties,surface morphology,chemical composition and dielectric properties of the films deposited with different Hf and Al precursor ratios were investigated,and In Ca Ox/HfAlOx FETs were constructed.The results show that when the precursor ratio of Hf to Al is 2:1,the device exhibits excellent performance,including a mobility of 17.3 cm2V-1 s-1 and a current on-off ratio of 1.2×107.In addition,the gain of the inverter constructed by connecting the device in series with the load resistance is as high as 13.4.It indicated that In Ca Ox/HfAlOx FET devices have potential applications in low-votage drives and logic circuits. |
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