Fabrication of Micro/Millimeter Wave Integrated Circuit by Novel Ferrite Plating Enhanced by Laser

本研究的目的是制作微/毫米波器件中的铁氧体薄膜非互易电路（即隔离器和环行器）制备的新型激光增强铁氧体电镀集成。铁氧体镀层的工艺温度低（<100 ℃），并且当用激光束增强时，沉积速率高，并且能够通过扫描进行选择性区域沉积。发现NiZn和MnZn尖晶石铁氧体的镀膜在微波频率下有很高的损耗。这是因为Ni和Mn的浓度较低，在尖晶石晶格中产生了Fe^<2+>离子。因此，我们开发了一种新的铁氧体电镀方法，利用螯合铁和其他金属离子的高碱性水溶液，通过该方法成功地提高了Ni和Mn的浓度。此外，我们已经制备了六角钡铁氧体薄膜的新型电铁氧体电镀利用交流电流。通过在室温下将NiZn和MnZn铁氧体的镀膜暴露在真空中，成功地降低了其介电损耗，而不损害其磁特性。遗憾的是，我们不能实现与非互易铁氧体器件集成的微波/毫米波器件，但是，我们已经展示了制造它们的潜在可行性。

The purpose of this study was to fabricate micro/millimeter wave devices in which ferrite-film nonreciprocal circuits (i.e.isolators and circulators) prepared by the novel laser-enhanced ferrite plating are integrated. The ferrite plating is low in process temperature (<100 C), and, when enhanced by laser beams, high in deposition rate and capable of selective area deposition by scanning. The plated films of NiZn and MnZn spinel ferrites were found to be highly lossy at microwave freguency. This was because concentration of Ni and Mn was low which gave rise Fe^<2+> ions in the spinel lattice. Therefore, we have developed a novel ferrite plating method utilizing highly alkaline aqueous solution of chelated Fe and other metal ions, by which the Ni and Mn concentration were successfully increased. Furthermore, we have fabricated films of hexagonal Ba-ferrite by novel electro-ferrite plating utilizing alternate electric current. The dielectric loss in the plated films of NiZn and MnZn ferrites were successfully reduced by exposing the films in vacuum at room temperature, without deteriorating their magnetic characteristics. We could not, unfortunately, realize the microwave/millimeter-wave devices integrated with the non-reciprocal ferrite devices, however, we have shown the potential feasibility to fabricate them.