Preparation And Performance Control Of SnO_x Thin Film And Study On Its Device

With the development of display technology,transparent electronic circuits should have a certain ability to process basic information.However,the current research and application of transparent oxide semiconductors are mainly based on n-type oxide semiconductor circuits.In order to realize CMOS transparent circuits with low power consumption,high noise tolerance,and diverse functions,it is urgent to develop high-performance p-type oxide semiconductor materials.SnO is considered to be one of the most promising p-type oxide semiconductor materials due to its excellent electrical properties,safety,non-toxicity,and abundant natural reserves.Due to the metastability of SnO,the prepared films are often accompanied by metallic Sn or SnO₂,which seriously affects the performance of the film.In this paper,SnO_x film refers to a film whose main component is SnO and accompanied by metal Sn or SnO₂.The SnO_x film has been systematically studied,and the main research contents include the following aspects:First of all,this thesis conducts a systematic study on the preparation of SnO_x thin films by magnetron sputtering.Through laser confocal microscopy,XRD,Raman spectroscopy,?-PCD,UV-visible spectroscopy,and Hall tests,the effects of sputtering power,sputtering pressure,oxygen partial pressure,and annealing temperature on the optical and electrical properties of the film were explored.Studies have shown that during sputtering at lower power,higher pressure,higher oxygen partial pressure,and annealing at higher temperature,although SnO_x films are mainly composed of SnO,part of Sn²⁺is oxidized to Sn⁴⁺,even SnO₂ crystal grains appear,and the film at this situation exhibits n-type conductivity.The SnO_x film prepared at too high power,too low air pressure,too low oxygen partial pressure and too low annealing temperature contains a large amount of metal Sn.The metal Sn brings a lot of electrons,resulting in the electron concentration of 10²⁰?10²¹ cm^-3,the film still exhibits n-type conductivity at this time.The SnO_x film prepared only in a very narrow window of process parameters exhibits p-type conductivity.The composition of the film is mainly SnO crystal phase,accompanied by a small amount of metallic Sn.A small amount of metallic Sn can inhibit the interstitial interstitial in the SnO lattice The formation of oxygen defects is inconducive to the p-type conductivity of the film.The SnO_x film with the best p-type performance is prepared under the conditions of 120 W,5 m Torr,6%oxygen partial pressure,and 200°C.The carrier concentration of the film is 2.66×10¹⁷ cm^-3,and the Hall mobility It is 2.64 cm² V^-1 s^-1.Secondly,the n-type Si and the optimized p-type SnO_x film are used to prepare a p-n junction to verify the feasibility of the p-type SnO_x film for the device.The turn-on voltage of the p-n junction is 1.42 V,the rectification ratio is 6.93×10³,and the ideality factor is 4.02.The response of p-n junction to different light is explored,and the time stability of p-n junction is explored.Finally,a p-SnO_x TFT with excellent performance was successfully fabricated,with a device mobility of 2.96 cm² V^-1 s^-1,a switching ratio of 1.6×10³,a threshold voltage of 3.44 V,and a subthreshold swing of 14.5 V dec^-1.