Preparation And Characteristics Of Aluminum Nitride Thin Film

In today's era of rapid development of science and technology, the equipment what people use is gradually smaller, more powerful and full-featured, work efficiency has repeatedly improved. This increasingly high demand for electronic components, and thus the performance requirements of electronic materials is also increasing. As an important part of modern communication system, thin film SAW device design flexibility (according to their own needs to be the corresponding design), simulation,digital compatibility, frequency selectivity, low loss, anti-interference ability, reliable and stable, and the device is small. These advantages and modern communications required, high-frequency, high performance, reliable and portable and so coincide.Piezoelectric film is an important material for the preparation of SAW devices, and its preparation needs to be carried out under stringent process conditions. By continuously controlling and improving the process to improve device performance and reduce film defects, it also relies on the choice of thin film materials.In this paper, AlN was selected as the basic material for the preparation of piezoelectric films, and the factors influencing the crystallization and electrical properties of piezoelectric films were studied systematically and emphatically. The effects of four main process parameters on the crystal quality, surface morphology,electrical properties and deposition rate of AIN piezoelectric films were investigated by four experimental series. The intrinsic phenomena of each experimental phenomenon were studied. Mechanism analysis and system research, through a large number of experimental research and theoretical exploration, the best preparation of AIN piezoelectric film technology.The main contents and research methods of this paper are as follows:First, combined with the laboratory conditions, the sputtering parameters analysis,design system experiments. The effects of substrate temperature, sputtering power,target distance and nitrogen and argon ratio on the surface morphology, surface roughness and crystal orientation of AIN piezoelectric films were investigated by XRD,AFM, SEM and step meter. As well as the influence of deposition rate. The experimental and experimental results show that under the condition of magnetron sputtering, the changes of various technological conditions have significant influence on the crystal quality, surface morphology, deposition rate and surface roughness of AIN films. The intrinsic mechanism of AIN film was analyzed, and the regularity of the crystal morphology, surface morphology, deposition rate and surface roughness of AIN film with the change of process parameters were obtained.Secondly, the influence of sputtering power, target distance, substrate temperature and nitrogen and argon ratio on the resistivity and leakage current of AIN piezoelectric thin films were investigated by using the control variable method and the IV mode and CV mode of the impedance analyzer. The The results show that the insulation of the sample is closely related to the crystal quality. And the internal mechanism of the experimental results is analyzed, and the regular results are summarized.Finally, the piezoelectric coefficient d33 is tested by PFM. The results show that the piezoelectric coefficient d33 exhibits a significant trend with the increase of crystal quality and C - axis orientation. And on the basis of the previous two steps, find out the best experimental process parameters under the respective grouping. At the same time,AIN piezoelectric films with high c-axis orientation, high crystal quality, good grain uniformity, low surface roughness and low resistivity were prepared.