FAST, RELIABLE MECHANICAL PROBING OF SUBMICRON FEATURES A NEW TOOL THAT COMBINES GAS-ASSISTED FIB AND MECHANICAL PROBING

Progress in electron-beam prober technology [1] has not eliminated the need for mechanical probing of ICs. Analog circuits, recent advanceme nt of mixed signal and low voltage digital designs all often require h igh accuracy, low noise signal acquisition. While not providing the ca pabilities of an e-beam, mechanical probes offer some significant adva ntages over non-contact measurement techniques: DC accuracy, small sig nal AC accuracy, single-shot measurements, low noise and high voltage (V>+/-10V) as well as the ability to inject a known signal into a spec ific circuit element. Mechanical probes have, however, been plagued by several drawbacks. These difficulties are primarily associated with t he limitations of optical microscopy - relatively low magnification (c ompared to charged particle Seam microscopes), poor spatial resolution and, above all else, small depth-of-focus. This paper describes a new tool which combines the capabilities of FIB, as a large depth-of-focu s, high resolution microscope, and a piezoelectric stage technology fo r sub-micron mechanical probe positioning in the vacuum chamber (MPC). Several novel applications are presented.