Study On Deposition And Characteristic Of LiNbO₃/Diamond Multiple Films For High Frequency SAW Devices

Surface acoustic wave devices (SAWD) have perfect character of mini capacity, high reliability,mutiple function and have being used widely in the scope of radar ,electronic battle,sonar,wireless communication,optics communication,broadcast system. With the wireless frequency being more and more lack,it is more and more urgent to get a kind of SAWD with the character of high frequency and high power for mobile communication and optics communication. In the same time, study of SAWD become an important scope ,which be worried by more people.Common SAWD ,such as quartz,LiNbO₃, LiTaO₃ and ZnO/ and so on,are not competent for some scope. SAW frequency F=V/λ.V stands for velocity of sound in the material.Because V = (E/ρ)^1/2,so F = (E/ρ)^1/2 /λ.E,ρandλstand for material elasticity value,material density and sound wave length.λis decided by IDT finger width.λ=4d.It is very difficult to reduce d for technic and process limit.So the material with high elasticity value and low density become the best choice.Through simulating ,Japan Nakahata computer make clear that:the velocity of sound in the material of LiNbO₃/ diamond multiple films,which is 4-5 times higher than the velocity of sound in the other material,and K2 can reach 9% through theory calculating.But so far there is not report about success in build SAWD yet.So our team begin in as follow six factors:(1)Deposite diamond film on Si base film by MPCVD,learn how to use facilities and get high purity diamond film,analyse diamond film.(2)Deposite (001) LiNbO₃ film on diamond film by using RFCVD.(3)Study process of depositing (001) LiNbO₃ film.(4) Design and simulate SAWD of LiNbO₃/IDT/diamond/Si multiple films.(5)Build LiNbO₃/IDT/diamond/Si SAWF by using optics carve process.(6)Build SAWF test system,test SAWF feacture by using Agilent E5070B (300KHz-3GHz),compare with the result which be got from software simulation.These six parts are the same impotant and relate with each other.Because of different task of all project in our team,there is not (2),(3)part in my paper.You can find content about (2),(3) parts in my partner's paper.