Nanostructured Inductors for Millimetre-Wave Applications

Abstract

Modern integrated and system-on-chip electronics require high-quality on-chip passive components. Existing inductor designs for microwave and millimetre-wave applications are typically prohibitively large and have low quality factors, requiring circuit designers to avoid integrating them or to use less desirable alternatives. This research studied vertical on-chip inductor structures through electromagnetic simulations and measurements on two materials. Simulations demonstrated that magnetic anisotropic materials produce useful inductances and quality factors at microwave frequencies. Thin magnetic films deposited using glancing angle deposition were fabricated as inductors and measured up to 70 GHz, producing inductances as high as 1 nH/um^2, which is significantly higher than other CMOS compatible technologies reported to date. The highest quality factor measured for the films was 3, with the measurements suggesting that the quality factor continues to increase at higher frequencies. Carbon nanotube inductors were also fabricated and measured, however, the contact resistance was found to be prohibitively high.