Characterization of probe contact noise for probes used in wafer-level testing

The characteristics of probe contact noise for tungsten probes used in wafer-level testing are presented. The effects of the biasing current and the probe contact resistance, R/sub c/, on the probe contact noise were investigated. This information is required for low-noise probe design as well as for reduction of the contact noise effects on sample noise measurements. The results show that the spectral density of the probe contact noise voltage has a 1/f frequency dependence and is proportional to V/sub c//sup 2/R/sub c//sup Gamma / where Gamma is a constant which has a value between -0.1 and 0.6 depending on the conditions of the contact interfaces.<
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