Preparation And Performance Study Of Tin-based Metal Oxide Field Effect Transistor

In recent years,with the rapid development of the electronic field,traditional silicon-based and organic semiconductor materials are limited by mechanical flexibility and electrical stability,and there is an urgent need to develop new semiconductor materials.The metal oxide thin film transistor（Thin-Film Transitor,TFT）has high mobility,high optical transmittance,large area uniformity and good electrical stability,and has been widely developed and applied in the field of flat panel display.Among the investigated metal oxides,indium-based oxides have been used as the electronic channel layer of high-performance TFTs.However,indium is a rare precious metal with low reserves in the earth,and it is also difficult to recover from constant dissipation and storage in transparent electrodes.Therefore,finding alternative elements is necessary.Tin oxide（SnO₂）has high intrinsic Hall mobility and large optical bandgap,its Sn⁴⁺and In³⁺have the same electronic configuration[Kr]（4d）¹⁰（5s）⁰,and have a large s-state spatial overlap,which is conducive to the transport of electrons.Meanwhile,Snis abundant and much cheaper than In,so Sn-based TFT is a promising alternative.This paper mainly studies the performance improvement and application of tin-based oxide field effect transistors,which are mainly divided into three parts.1.SnO₂thin film was prepared by sol-gel method and integrated into thin film transistor as channel layer.In order to optimize the electrical properties of SnO₂-based TFTs,the effect of oxygen plasma treatment（different plasma power and treatment time）on the semiconductor layer after thermal annealing was investigated,and it was found that oxygen vacancies were significantly reduced after oxygen plasma treatment.The current modulation capability of the TFT can be adjusted by changing the plasma power and processing time.SnO₂-based TFTs exhibited smaller V_THand larger I_on/I_offunder oxygen plasma treatment at 40 W for 90 s.It is shown that oxygen plasma treatment can significantly improve the electrical properties of field effect transistors.In order to achieve low operating voltage and improve mobility,20 nm aluminum oxide（Al₂O₃）was deposited by atomic layer deposition（ALD）as a high-κdielectric layer,which showed better performance.With a large switching ratio of about 10⁷,an operating voltage as low as 0.14 V,and a small subthreshold swing of 570 m V/dec,its mobility can reach5.57 cm²V^-1s^-1.It shows great application potential in the field of transparent flexible electronic devices.2.SnZrO nanofibers with different zirconium（Zr）doping concentrations were prepared by electrospinning process and integrated with Field Effect Transistor（FETs）.The carrier concentration decreased significantly and the on-off ratio increased significantly.Therefore,doping the carrier inhibitor Zrcan reduce oxygen vacancies and improve the electrical performance of the device.Using spin-coated highκ-ZrOx as the dielectric layer of SnZr_8%O nanofiber FETs,it was found that the carrier mobility was increased to 2.35 cm²V^-1s^-1and the threshold voltage was reduced to 0.12 V,with a large switching ratio of 1×10⁷and the smaller subthreshold swing of 120 m V/decade.This is suitable for low power consumption and low drive voltage device applications.3.The application of SnZrO nanofibers was further explored.Using H+/PVA polymer electrolyte as the dielectric layer and SnZrO nanofiber as the active layer,a synaptic electric double-layer transistor was fabricated,and the short-range plasticity under single pulse response was studied.This has great significance for the exploration of neuromorphic chips.