High Q microwave inductors on silicon by surface tension self-assembly

A new technique is presented for the fabrication of three-dimensional metal structures by surface tension-induced folding of flat structures. This fully parallel. low temperature method is suitable for post-processing on integrated circuits, and in a first application is used to decouple inductors for radio- and microwave-frequency integrated circuits from their substrates, to reduce losses and parasitic capacitance. Meandered microwave inductors have been fabricated on a low resistivity silicon substrate, and a peak Q of 10 was measured, at 1GHz, for a 2nH inductor standing vertically, compared to a peak Q of 4 for the same structure before self assembly.