Using Energy Dispersive Spectroscopy (EDS) to Determine the Resistance of FIB Jumpers for Circuit Edit

Abstract

Abstract A key capability of focused ion beam (FIB) tools is the ability to deposit conductive materials by introducing organometallic precursors such as tungsten hexacarbonyl [W(CO)6] or (methylcyclopentadienl) trimethyl platinum [C9H17Pt]. The FIB deposited metal is often used in applications such as the modification of integrated circuits (ICs) by creating new electrical connection on the device. The electrical properties of the FIB material are of particular concern to high speed digital and radio frequency (RF) circuit designers because the resistivity of the FIB deposited metal is orders of magnitude higher in value than the near bulk resistivity value of the metals used in IC manufacturing. In this paper, we developed a correlation between the chemical composition of the FIB deposited metal and the electrical resistivity using an effective media theory (EMT) model. Analysis shows that gallium from the ion beam is the dominant contributor to lowering the resistivity of the jumper. The results of this work and model allow us to understand the role the chemical elements play in the electrical resistance of the FIB electrical jumper and to estimate the FIB metal resistance from energy dispersive spectroscopy (EDS) analysis and the geometry.