On-Chip Inductors with Self-Rolled-Up SiNx Nanomembrane Tubes: A Novel Design Platform for Extreme Miniaturization

Wen Huang †‡, Xin Yu †, Paul Froeter †, Ruimin Xu ‡,Placid Ferreira §, and Xiuling Li *†

^† Department of Electrical and Computer Engineering, Micro and Nanotechnology Laboratory, University of Illinois, Urbana, Illinois 61801, United States

^‡ EHF Key Laboratory of Fundamental Science, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China

^§ Department of Mechanical Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States

Nano Lett., Article ASAP

DOI: 10.1021/nl303395d

Publication Date (Web): November 21, 2012

Copyright © 2012 American Chemical Society

nductors are essential components of radio frequency integrated circuits (RFICs). While the active devices in RF systems downscale steadily, inductors have not been able to keep up with the pace of continual miniaturization because of the trade-off between size and performance as well as fabrication complexity. Strain-induced self-rolled-up nanotechnology allows the formation of three-dimensional (3D) architectures, such as multiple-turn spiral tubes, through planar processing. Here, we report on using 3D SiN_x tubular structures with accompanying prepatterned metal layers, as a novel on-chip tube inductor design platform. We found, by an equivalent lumped circuit and electromagnetic modeling, that the 3D metal spiral structure has the ability to significantly better confine magnetic field compared to conventional planar spiral on-chip inductors. More than 100× reduction in footprint can be realized using this platform while achieving excellent electrical performance, including large inductance, high quality (Q) factor, and high self-resonance frequency (f₀).