Importance

Loading Importance Indicators...

Abstract

A wafer probe station adapted for low-current measurements provides electrically active upper and lower chuck assembly elements where air gaps are provided between a major portion of either a lower or nonlower surface on the upper chuck assembly element and a corresponding conductive surface on or connected to the lower chuck assembly element thereby minimizing leakage currents therebetween. The chuck assembly elements are preferably enclosed by an environment control enclosure having a sidewall portion relative to which the upper chuck assembly element can move laterally. During such movement, the upper chuck assembly remains in constant spacing with a conductive member that laterally surrounds it so as to stabilize electro-magnetic conditions. Concurrently, the sidewall portion is kept motionless relative to the probe holder which keeps contaminants away from the region immediate to the upper chuck assembly element, including any moisture droplets that have condensed during low-temperature testing. Modularity of the chuck assembly elements is preferably facilitated by detachable electrical connections. Preferably, the lower chuck assembly element, the conductive member and an upper guard plate surround the upper chuck assembly element for guarding thereof so as to further minimize leakage currents and reduce settling times.

Loading the Abstract Image...

First Claim