Study On Depositing ZnO/diamond Multi-film Suitable For SAW Device

As the processing information amount of modern electronics increases rapidly ,the carrier wave in communication must move to higher frequency band . Surface acoustic wave devices(SAWD) is one of the key elements in modern communication system.The central operating frequency of SAWD'F'is defined as F=V/L,among which V means the SAW speed of the used material ,and L is the period of IDT.At present ,it is difficult for SAW devices operating under GHz frequency because of the limitation of materials and fabrication technology. Diamond has a highest acoustic speed (11000ms-1),but it is not piezoelectric material.It cannot change the energy of electromagnetic wave into the energy of surface acoustic wave.We can deposit an oriented piezoelectric film on diamond film for studying multi-film SAW devices. It is of great importance to analyze the processing of CVD diamond film.We have deposited diamond films by DC arc plasma jet CVD and we have studied producing ZnO/diamond multi-films which are suitable for the fabrication of surface acoustic wave device. The diamond films and ZnO films are structurally analyzed using techniques such as X-ray diffraction,scanning electron microscopy,Roman to determine their crystal structure ,surface morphology and composition distribution .Firstly , we have deposited diamond films by DC arc plasma jet CVD,and investigated the effects of dealed Mo substrate,the base of temperature,the proportion of CH4 for performance of diamond films.We have analysed the results of test,too.Finally,under the optimized condition highly property diamond films are fabricated which are suitable for the fabrication of surface acoustic wave device and which are lower granulation after polishing,and approximately one millimeter thickness,its size parameter is 60mm×1.4mm. From its X-ray diffraction,scanning electron microscopy,the diamond film is of higher quality.Secondly,Using RF magnetron sputtering method ,we deposited ZnO on polishing diamond film.Through the result we can see when the temperature of diamond substrate is 250℃, ZnO film is very polishing. The films were analyzed by XRD, SEM and other means. Get the result that when argon oxygen ratio is 4:4 and the pressure is 1Pa , the optimal temperature of Si substrate is 250℃. We prepared high degree of c-axis orientation of the ZnO films on the substrate of polished diamond.From that we can come to a conclusion,the quality,the C-axis orientation and polishing of fabricated ZnO/diamond multi-films are suitable for SAW device.It can be used in SAW device of higher frequency.