Focused ion beam (FIB) tools are used to perform "circuit edit," (CE), in which existing integrated circuit devices are modified to create prototype devices that simulate potential mask changes. Although ion milling at low keV is common in TEM sample preparation, the technique has not become commonplace for CE applications. This is because most commercial FIB systems are optimized for either 30 or 50 keV. Recent work in the laboratories of FEI and Intel have attempted to apply low keV FIB processing to cutting small copper lines on advanced IC devices. The majority of this paper focuses on water-assisted, low keV copper etching. Secondary objectives of this work are to raise general awareness among FIB users of the potential benefits of low keV processing, to speculate on the physical mechanisms involved, and to discuss some of the technical difficulties associated with low keV FIB operation.