Above: This example shows a spiral inductor surrounded by ground straps.
A spiral inductor on silicon is investigated in detail using the free Sonnet Lite 3-D planar electromagnetic analysis. First, a baseline inductor is evaluated and the Sonnet Lite model is simplified for the fastest possible analysis while maintaining accuracy. Then various parameters of the inductor are modified in order to determine how they affect loss. Modified parameters include the dielectric constant and thickness of a thin insulating dielectric layer, line width and spacing. Quantitative evaluation of analysis error bounds is also provided.
In this paper, a baseline design is presented for a spiral inductor on lossy (20 S/m) silicon, with the spiral metal separated from the silicon by a thin (2 um) insulating material. A short study is presented on the physical factors that can be manipulated in order to influence the loss characteristic of the inductor design. Using Sonnet Lite, these spiral design changes can be quickly and accurately evaluated on the computer.
This article by Dr. James C. Rautio was published in the September 1999 issue of Microwaves & RF Magazine (p.165-172). Click on the
link below to view a PDF version of the paper. Click on the
link at the top of this page to download the Sonnet
project files, and analyze the examples presented by Dr. Rautio on your Sonnet Lite installation.
Please note the paper was written prior to release 8, but the content is still valid for release 8.
Download
