High Q-factor On-chip 3-D Inductor for Wireless applications

In current trend for portable wireless communication applications, we require high Q on-chip inductors. In this paper an on-chip 3-D spiral inductor is proposed. High quality factor is achieved by reducing oxide capacitance between substrate and conductor considering permittivity of a substrate. Losses in the structure are reduced by considering high conductivity material like copper or gold. In this paper, 3-D inductor model is designed based on multi turn inductor concept embedded using multilayer CMOS topology. The proposed inductor is rectangular in geometry having maximum quality factor nearly 270 with inductance of 132nH at 40MHz frequency. Realization of designed inductor is done by using IE3D EM filed solver with the help of basic lumped pi-model. Proposed inductor is compared with the basic on-chip planar inductor model. In comparison proposed inductor shows better results than basic model in terms of Quality factor and Inductance. The proposed on-chip 3-D inductor has (47-162) % in terms of Q-factor and an improvement of (18-28) % inductance value in the frequency range of (30-100) MHz w.r.t planar inductor. The proposed high Qinductor can be used in various wireless applications for RF and microwave subsystems. On-chip area of proposed inductor is 10×10mm.