A comparison of pad metallization in miniaturized microfabricated silicon microcantilever-based wafer probes for low contact force low skate on-wafer measurements

Abstract Miniaturized, microfabricated microelectromechanical systems-based wafer probes are used here to evaluate different contact pad metallization at low tip forces (<mN) and skate on the on-wafer pads. The target application is force RF for measurements which cause minimal damage both Low enables use of softer, more conductive metallisation. We have studied four thin film metals based their electrical resistivity micro-hardness: gold, nickel, molybdenum, chromium. pads sizes were micrometre (1.9 × 1.9 µ m 2 ) sub-micrometre (0.6 0.6 ). resistance Au–Au, Ni–Au, Mo–Au, Cr–Au was measured as a function deflection. (loading) contacts evaluated from deflection cantilever. It observed that an overtravel 300 nm resulting in ?400 N sufficient achieve <1 ? gold pad. Our results compared with analytical model loaded metal-metal contacts—a reasonable fit found. A larger other metals—but hardness may be advantageous when probing materials. Using combination rigid silicon cantilever (>1000 Nm ?1 small enabled us show it length (in surface) determines rather than total area.