Effect Of TiO₂ Buffer Layer On Structure And Properties Of Bimetallic Film On Quartz Substrate

Thin film materials can greatly increase the size and integration of devices,so they are developing very rapidly.Among them,precious metal films have always been the focus of research due to their good electrical conductivity,thermal conductivity and corrosion resistance.Among them,Au film is the most typical and is also the hot spot of research.The composite structure formed by depositing pure Au on a non-metallic substrate and formed of a metal-insulator has a unique photoelectric property that is completely different from that of the bulk metal.The composite structure can have metal or insulating behavior,has a strong plasma effect and local electric field enhancement can be used as a nonlinear optical device,a plasma sensor,a photoelectric component,etc.,and has broad application prospects.The SiO₂ substrate has the best quality factor and is irreplaceable,but the thermal expansion coefficient between the SiO₂(5x10^-7/K)substrate and Au(14.2x10^-6/K)is very different,causing serious The thermal mismatch does not allow a direct deposition of an Au film on the SiO₂ substrate.It is necessary to construct an intermediate layer between the two layers.The thermal expansion coefficient of the intermediate layer is between the SiO₂ substrate and the Au film.There are two choices of the current intermediate layer.The first one is a metal layer,such as a Cr layer,but the intermediate layer of the metal film is greatly damped,which has a great influence on the quality factor of the SiO₂ substrate,and Cr and Au in the post-heat treatment process.Interdiffusion between them,which seriously affects the conductivity of Au.The second type is an oxide layer,such as TiO₂.The intermediate layer is less damped,affecting the quality factor of the SiO₂ substrate to a lesser extent and does not diffuse with the Au film during the heat treatment,thereby ensuring the Au film to some extent.Electrical conductivity.In this paper,a layer of TiO₂ film was deposited on the surface of SiO₂substrate by atomic layer deposition technique.By changing the ALD process parameters,such as substrate temperature,cycle number and Ti:O injection time ratio,TiO₂ films of different states were obtained and TiO₂ films were obtained.Heat treatment.The experimental results show that the TiO₂ film prepared by ALD has uniform thickness,flat surface and uniform deposition on SiO₂ substrate,but the change of heat treatment process and the increase of substrate temperature do not crystallize TiO₂ film.Subsequently,a layer of Au film was deposited by magnetron sputtering on the original and different heat treated TiO₂ films prepared above.The effect of magnetron sputtering on the crystallinity of Au film was studied,and different processes were studied.The effect of TiO₂ film on the bond strength and conductivity of Au film.The experimental results show that the addition of substrate temperature of 200°C during magnetron sputtering is beneficial to the crystallization of Au film,and the quality of Au film deposited by magnetron sputtering proces s parameters of 0.1 A-15 min is better.TiO₂ film can be used as the intermediate buffer layer between Au film and SiO₂ substrate.With the increase of the thickness of TiO₂ film or the heat treatment temperature of TiO₂ film,the bond strength of Au film film is gradually increased,the maximum can reach 0.3N,and the scratch is Only the detachment of the Au film,the SiO₂ film still exists on the SiO₂ substrate,and the polishing of the SiO₂ substrate has little effect on the bonding force of the film of the Au film,and the electrical conductivity.Since the bonding strength of the Au film film with TiO₂ film as the middle layer is still small,the performance of flashing Cr and Au film on TiO₂ film is explored.The results show that the magnetron sputtering Cr 3 s and Au film film base have significant binding force.Increase,reach 10 N,and the conductivity decreases with the increase of the heat treatment time,which means that the interdiffusion between Cr-Au does not occur during the heat treatment.