The Growth And Properties Of In₂O₃ Films Deposited By High Power Pulsed Reactive Magnetron Sputtering

With the development of the war,many countries begin to pay attention to the stealth capability of aircraft.Aircraft with stealth capability will greatly improve the survival probability of the battlefield and the completion probability of the target strike.The aircraft cockpit or optoelectronic pod with the function of searching,discovering,and tracking the target is an important part of it.An aircraft cockpit or photoelectric pod will produce a large radar cross-section due to its special cavity structure,which makes it easy to be detected by radar.Therefore,in the modern battlefield environment with complex electromagnetic interference,optoelectronic detection systems urgently need to have strong radar stealth to resist external electromagnetic detection.Indium oxide films can be used as a material for electromagnetic shielding on the optoelectronic windows surface of aircraft because of their high transmission properties in the visible to mid-infrared wavelengths and high electrical conductivity.In order to obtain the stealthy layer required for the optoelectronic window,the indium oxide films were deposited by high power pulsed reactive magnetron sputtering（Hi PIMS）technology in this dissertation.The dynamic process of target surface chemical state and ions bombardment during thin film deposition was investigated by tuning the hysteresis in the reactive sputtering process.The scientific problem of poor glow discharge stability caused by the changing of secondary electron yield were solved.Therefore,the problems of deposition stability and poor sample reproducibility in the transition mode was solved,resulting in indium oxide thin films and nitrogen-doped n-type and p-type indium oxide thin films show excellent crystalline quality and optoelectronic properties.The function of high infrared band transmittance and electromagnetic shielding were realized by modifing the lattice structure and carrier-photon interaction.Firstly,according to the poor stability of glow discharge in the transition mode,the dynamic reaction process between the reactive gas and target atoms was found,which eliminated the transition range and realized the precise control of the reaction by studying the physical process of hysteresis.The reaction of the target surface with the reaction gas will determine the three sputtering modes（metallic mode,transition mode,and poisoning mode）.In the power mode,high pumping rates have a wide hysteresis,while low pumping rates respond with a narrow hysteresis.In the voltage mode,the transition region is not obvious by manipulating the production of secondary electrons.Due to the formation of a double layer of electrons and positive ions in the plasma,the ionization zone was found to move along the-E×B direction,which had an opposite orientation of electrons that with a counterclockwise motion.Secondly,in order to solve the problem of the contradiction between high transmittance and high conductivity of indium oxide thin film,the deposition characteristics of the film under three deposition modes of hysteresis were used to reveal the growth mechanism of the high crystalline quality of indium oxide thin film.By tailoring the lattice structure and carrier-photon interaction,indium oxide thin films with high transmission and high conductivity are achieved.According to the hysteresis,in the metallic,transition,and poisoning mode,there was a significant decrease in the concentration of oxygen vacancies in the film,leading to a concomitant decrease in the conductivity of films.However,the decrease in free electrons led to an increase in the transmittance and plasma wavelength in the infrared band.High ionization rates and substrate temperatures allowed indium oxide films to have a columnar crystal structure with（222）crystal planes growth,which perpendicular to the substrate surface.Finally,the N element doped indium oxide thin films were studied in the transition mode and poisoning mode to grow n-and p-type transparent conductive thin films.The n-and p-type In₂O₃-N thin films with excellent optoelectronic properties were deposited by revealing the defects’type and formation mechanism.After N element doping,the films deposited in transition mode and poisoning mode had In-O,In-N,and O-N bonds at the same time.In transition mode,even though the In-N bonds and O-N bonds allowed the film to has a certain amount of holes,the concentration of holes was less than the concentration of free electrons,which presents the characteristics of an n-type film.The p-type films were deposited in the poisoning mode because the concentration of holes in the film was larger than the concentration of electrons after doping.The best figure of merit and electromagnetic shielding efficiency of In₂O₃ films were deposited at room temperature.The figure of merit and electromagnetic shielding efficiency of In₂O₃ films obtained at the substrate temperature of 400°C were the second best compared with other methods.