GOALI: High Permeability Ferrite Cores for Micro-Inductors

磁性材料具有独特的特性，这推动了它们与微电子和微电子机械(MEM)设备的集成。各种微制造技术正被积极追求。在这项建议中，提出了一种新的技术，以沉积适用于微型磁性器件的氧化物磁性材料薄膜。所选择的磁性材料是初始磁导率在1,000-10,000之间的低矫顽力软铁氧体(锰锌铁氧体和镍锌铁氧体)。这种薄膜将在微电感、微型变压器和其他片上磁性器件中得到广泛的应用。这些薄膜将通过电泳法沉积，即从纳米到微米尺寸的铁氧体悬浮在溶液中的电沉积。铁氧体粉末将与铁氧体公司Ferronics和阿尔弗雷德大学先进陶瓷技术中心(CACT)合作，通过气流研磨技术制备。将开发一种电化学过程，以在硅片上均匀沉积磁性薄膜。将对薄膜的磁性、厚度均匀性和附着力进行表征。随后，将开发一种光刻技术来图案化铁氧体薄膜以形成微电感的铁芯。基础研究将通过模拟沉积过程来了解受限区域中的颗粒分布和电沉积对薄膜形貌的影响。这些薄膜和结构的磁性将被测量。这些薄膜结构将与半导体衬底上的铜微电感集成在一起。电感将使用电磁软件进行解析设计和建模。制造将利用罗切斯特理工学院(RIT)的IC制造设施进行。电感和Q因数等电气测量将使用网络分析仪和阻抗测量仪进行。优化后的结构将在硅片上制作电路。这将是一个介于微电子工程、电气工程、物理和电化学之间的多学科实验和理论研究计划。此外，还有来自行业和CACT中心的支持。该项目将使微电感和微磁器件的片上磁性元件的制造成为可能。所提出的工艺也可用于集成其他磁性材料，如硬质铁氧体和微波铁氧体。

Magnetic materials have unique properties that are driving their integration with microelectronic and micro-electro-mechanical (MEM) devices. Various microfabrication technologies are being pursued aggressively. In this proposal, it is proposed to develop a novel technique to deposit oxide magnetic material films applicable to micro magnetic devices. The magnetic materials chosen for the proposed study are low coercivity soft ferrites (manganese zinc and nickel zinc ferrites) with initial permeability ranging from 1,000-10,000. The films will find extensive applications in micro inductors, micro transformers and other on chip magnetic devices. These films will be deposited by electrophoresis i.e electrodeposition from nano to micron size ferrite particles suspended in a solution. The ferrite powders will be prepared by jet milling technique in conjunction with a ferrite company Ferronics and the Center for Advanced Ceramic Technology (CACT) at Alfred University.An electrochemical process will be developed to get uniform deposition of magnetic films on silicon wafers. The films will be characterized for their magnetic properties, thickness uniformity and adhesion. Subsequently, a lithographic technique will be developed to pattern ferrite films to form the cores of micro inductors. Fundamental investigations will be made to understand the effect of particle size distribution and electrodeposition in confined regions on the film morphology by modeling the deposition process. The magnetic properties will be measured on these films and structures. These film structures will be integrated with copper micro-inductors on semiconductor substrates. Inductors will be designed and modeled analytically and using an electromagnetic software. The fabrication will be carried out utilizing the IC fabrication facility at Rochester Institute of Technology (RIT). Electrical measurements such as inductance and Q-factor will be done using network analyzer and impedance meters. The optimized structures will then be fabricated with circuitry on silicon wafers.This will be a multidisciplinary experimental and theoretical research program between Microelectronic Engineering, Electrical Engineering, Physics and Electrochemistry. In addition, there is support from industry and the CACT center. The project will enable fabrication of on-chip magnetic components for micro-inductors and micro magnetics. The proposed process can also be utilized to integrate other magnetic materials such as hard ferrites and microwave ferrites.