Thin-film Inductor Design And Preparation

Along with the improvement in the level of advancement of technology and social information, wireless communication technologies are constantly in the direction of miniaturization of high frequency. All kinds of electronic systems become more and more integrated, their frequency also become higher and higher. As one of the three main passive elements, inductor has been widely used in many fields. Based on the introduction of magnetic film, the inductance could be enhanced and reduce the size, the high frequency characteristic could be improved for the film inductor, which will be the mainstream in the future. So in nowadays, study of the film inductor has become one of the hotspots.In this paper, status of the film inductor study is firstly summarized, analysis the film inductor’s basic theory, key performance indicators and loss mechanisms. We simulate the film inductor with ansoft HFSS, analysis of various parameters of the inductor and the properties of the materials parameters on the inductance value L and quality factor Q, as well as the impact of operating of frequency, and optimize these properties, finally, we have the basic structure parameters and material parameters of the inductor. The turns n is10, line width w is70μm, lines gap s is30μm, the conductor’s thickness t si2μm, lines of length d is600μm, and the substrate resistivity ρsi is more than10Ω·cm.Under the guidance of the simulation results, we select Fe-Co-SiO2film as a core material, with the condition of our laboratory, prepared thin film by magnetron sputtering, analyzed the film’s performance, get the optimization film parameters. The result show that the film has a certain degree of anisotropy and high saturation magnetization, the film’s coercivity of the easy axis and hard direction is5Oe and8Oe,The anisotropy field is about55Oe; Saturation magnetization is20.8KG, the natural resonance frequency of the film is about3GHz and the resistivity is1500W·cm.Finally, we combine film technology of lithography process, etching and electroplating process to producing thin film inductors, and test the inductors at high frequency. According to the results, when f is about2GHz, the inductance L and quality factor Q are enhanced by23%and27%, the integration improve the overall performance of the inductor. We get a high-performance thin film inductor from the experimental.