کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1805231 1024674 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A new generation of CMOS-compatible high frequency micro-inductors with ferromagnetic cores: Theory, fabrication and characterisation
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
A new generation of CMOS-compatible high frequency micro-inductors with ferromagnetic cores: Theory, fabrication and characterisation
چکیده انگلیسی

A new generation of CMOS-compatible micro-inductor prototypes with magnetic cores were realized, characterised as well as theoretically modelled in a frequency range up to 4 GHz, a frequency range where, e.g., mobile communication and global positioning systems (GPS) are operated. The micro-inductor's electrical magnitudes like inductance (L) and quality factor (Q) were theoretically described by means of an equivalent circuit model taking the frequency behaviour of the magnetic film core, expressed by the Landau-Lifschitz and Maxwell equations, into account. Six inch targets were used to deposit metallic layers (Al99Si0.5Cu0.5), diffusion barriers (Si3N4), insulating layers (SiO2) and magnetic films (Fe39Co30Ta8N23) by DC or reactive r.-f.-magnetron sputtering. All film materials were patterned by NUV-lithography (Near Ultra Violet), plasma beam milling and reactive ion etching to form the micro-inductors on 4-inch silicon wafers. The inductor windings are arranged in a way that they possess a low resistance and generate a quasi closed flux at the end of the cores to minimise eddy current losses in the silicon substrate. In order to diminish demagnetising effects in an efficient working core the magnetic films were patterned into micro squares with lateral dimensions of 20 and 100 μm with 100 nm in thickness. More magnetic volume and a higher micro-inductor cross-section was achieved by producing 100 nm magnetic double layers separated by a 800 nm thick Si3N4 inter-layer. To guarantee a sufficiently high cut-off frequency of the magnetic films, they were annealed in a static magnetic field at a temperature of 400 °C for uniaxial anisotropy induction. This represents a temperature treatment where aluminium CMOS processes take place. As a result of patterning, the magnetic film material exhibited a remarkable increase of the cut-off frequency from 2 GHz in laterally extended films up to 3.2 GHz which could be also observed in the measured frequency dependent inductance and quality factor. This was accompanied by an acceptable decrease of the initial permeability that still enabled initial inductances between 1 and 2 nH to be attained.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 302, Issue 2, July 2006, Pages 321–326
نویسندگان
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