Research On Large Scale Substrate Aluminum Nitride Film Based On Magnetron Sputtering Preparation Technology

Micro-Electro-Mechanical System(MEMS)refers to micro-devices or systems that can be manufactured in batches,integrating micro-mechanisms,micro-sensors,micro-actuators,and signal processing and control circuits,communications,and power are equal to one.Working principle is that the external environment physical,chemical and biological signals are input and converted into electrical signals by micro sensors.After signal processing(analog or digital signals),micro-actuators perform actions to achieve "interaction" with the external environment.Film Bulk Acoustic Wave Resonators(FBAR)have attracted wide attention with the development of MEMS technology due to their excellent performance such as small size,low loss,large power capacity,and integration.As one of the most commonly used piezoelectric thin film materials,aluminum nitride(AlN)film has a polycrystalline preferred orientation.The transmission speed of the crystal surface acoustic wave along the c-axis direction is the largest,it is the fastest piezoelectric material with the highest acoustic wave velocity among all known piezoelectric materials,and is often used to study FBAR.In this paper,by using reactive magnetron sputtering,AlN pressure is prepared on a large-size(8-inch)substrate by changing the film-forming conditions such as different power supply,substrate bias,nitrogen flow rate,the distance between the sputtering target and the substrate Conduct electrical film and conduct in-depth research on its performance.The experimental results show that the sputtering power affects the film thickness uniformity and c-axis orientation of the AlN film,and the deposition rate also has an important effect on the film uniformity;the effect of substrate bias on the film thickness uniformity is negligible;the nitrogen flow rate The uniformity of the film thickness of the AlN film also has an important effect;the distance between the target and the substrate affects the number of atom collisions and the deposition distribution during the deposition process,and the value of the film thickness uniformity decreases first as the distance between the target and the substrate increases Increased,and finally the optimal value of film thickness uniformity was 0.72%.The orientation of the AlN film was obtained by X-ray diffractometer(XRD),the surface grain growth morphology of the film was obtained by scanning electron microscope(SEM),the thickness of the film was obtained by the film thickness meter,the uniformity of film formation was good,the stress tester was The stress of the AlN film was analyzed.Using Degas and PreClean methods to further optimize the uniformity and denseness of AlN thin films and carry out two-step film formation,the final study found that the uniformity of the film has been significantly improved,and the uniformity value has been reduced to 0.55%,which has the future industrial production Significance.