Abstract: A probe station includes a fully guarded chuck assembly and connector mechanism for increasing sensitivity to low-level currents while reducing settling times. The chuck assembly includes a wafer-supporting first chuck element surrounded by a second chuck element having a lower component, skirting component and upper component each with a surface portion extending opposite the first element for guarding thereof. The connector mechanism is so connected to the second chuck element as to enable, during low-level current measurements, the potential on each component to follow that on the first chuck element as measured relative to an outer shielding enclosure surrounding each element. Leakage current from the first chuck element is thus reduced to virtually zero, hence enabling increased current sensitivity, and the reduced capacitance thus provided by the second chuck element decreases charging periods, hence reducing settling times.

Abstract: A wafer probe station is equipped with an integrated environment control enclosure substantially surrounding a supporting surface for holding a test device, such enclosure limiting fluid communication between the interior and exterior of the enclosure and preferably also providing EMI shielding and a dark environment. The limited communication between the interior and exterior of the enclosure is kept substantially constant despite positioning movement of either the supporting surface or probes. The positioning mechanisms for the supporting surface and probes each are located at least partially outside of the enclosure.

Abstract: A wafer probe station is equipped with an integrated environment control enclosure substantially surrounding a supporting surface for holding a test device, such enclosure limiting fluid communication between the interior and exterior of the enclosure and preferably also providing EMI shielding and a dark environment. The limited communication between the interior and exterior of the enclosure is kept substantially constant despite positioning movement of either the supporting surface or probe holders. The positioning mechanisms for the supporting surface and probe holders each have portions located at least partially outside of the enclosure for transferring movement mechanically to the surface or holders, respectively.

Abstract: A probe station includes a fully guarded chuck assembly and connector mechanism for increasing sensitivity to low-level currents while reducing settling times. The chuck assembly includes a wafer-supporting first chuck element surrounded by a second chuck element having a lower component, skirting component and upper component each with a surface portion extending opposite the first element for guarding thereof. The connector mechanism is so connected to the second chuck element as to enable, during low-level current measurements, the potential on each component to follow that on the first chuck element as measured relative to an outer shielding enclosure surrounding each element. Leakage current from the first chuck element is thus reduced to virtually zero, hence enabling increased current sensitivity, and the reduced capacitance thus provided by the second chuck element decreases charging periods, hence reducing settling times.

Abstract: A wafer probe station is equipped with an integrated environment control enclosure substantially surrounding a supporting surface for holding a test device, such enclosure limiting fluid communication between the interior and exterior of the enclosure and preferably also providing EMI shielding and a dark environment. The limited communication between the interior and exterior of the enclosure is kept substantially constant despite positioning movement of either the supporting surface or probe holders. The positioning mechanisms for the supporting surface and probe holders each have portions located at least partially outside of the enclosure for transferring movement mechanically to the surface or holders, respectively.

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.

Abstract: A low-current pogo probe card for measuring currents down to the femtoamp region includes a laminate board having a layer of conductive traces interposed between two dielectric layers. A plurality of probing devices, such as ceramic blades, are edge-mounted about a central opening so that the probing needles or needles included therein terminate below the opening in a pattern suitable for probing a test subject workpiece. A plurality of pogo pin receiving pad sets, each including a guard pad, occupy the periphery of the board. Each guard pad is electrically connected to a trace from the layer of conductive traces. The pad sets may be connected to the probing devices by low noise cables or traces. Air trenches separate the pad sets for reducing cross talk and signal settling times.

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 remain in constant spacing with a conductive member that laterally surrounds it so as to stabilize electromagnetic 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.

Abstract: A wafer probe station is equipped with an integrated environment control enclosure substantially surrounding a supporting surface for holding a test device, such enclosure limiting fluid communication between the interior and exterior of the enclosure and preferably also providing EMI shielding and a dark environment. The limited communication between the interior and exterior of the enclosure is kept substantially constant despite positioning movement of either the supporting surface or probe holders. The positioning mechanisms for the supporting surface and probe holders each have portions located at least partially outside of the enclosure for transferring movement mechanically to the surface or holders, respectively.

Abstract: A wafer probe station is equipped with an integrated environment control enclosure substantially surrounding a supporting surface for holding a test device, such enclosure limiting fluid communication between the interior and exterior of the enclosure and preferably also providing EMI shielding and a dark environment. The limited communication between the interior and exterior of the enclosure is kept substantially constant despite positioning movement of either the supporting surface or probe holders. The positioning mechanisms for the supporting surface and probe holders each have portions located at least partially outside of the enclosure for transferring movement mechanically to the surface or holders, respectively.

Abstract: A probe station includes a fully guarded chuck assembly and connector mechanism for increasing sensitivity to low-level currents while reducing settling times. The chuck assembly includes a wafer-supporting first chuck element surrounded by a second chuck element having a lower component, skirting component and upper component each with a surface portion extending opposite the first element for guarding thereof. The connector mechanism is so connected to the second chuck element as to enable, during low-level current measurements, the potential on each component to follow that on the first chuck element as measured relative to an outer shielding enclosure surrounding each element. Leakage current from the first chuck element is thus reduced to virtually zero, hence enabling increased current sensitivity, and the reduced capacitance thus provided by the second chuck element decreases charging periods, hence reducing settling times.

Abstract: A probe station is equipped with an integrated guarding system which facilitates the use of the station for low-current measurements, as well as integrated Kelvin connections to eliminate voltage losses caused by line resistances. The station has a chuck assembly which consists of at least three chuck assembly elements. A first element supports the test device, while an underlying second element acts as a guard to reduce leakage currents. These elements are electrically insulated from each other and from their underlying supporting structure, which is the third element. Ready-to-use, selectively detachable electrical connector assemblies provide for signal and guard connections to the first and second chuck assembly elements, respectively, as well as providing Kelvin connections thereto. The capacitance between the respective chuck assembly elements is extremely low due to the provision of air space as the primary electrical insulator.

Abstract: A probe station is equipped with an integrated guarding system which facilitates the use of the station for low-current measurements, as well as integrated Kelvin connections to eliminate voltage losses caused by line resistances. The station has a chuck assembly which consists of at least three chuck assembly elements. A first element supports the test device, while an underlying second element acts as a guard to reduce leakage currents. These elements are electrically insulated from each other and from their underlying supporting structure, which is the third element. Ready-to-use, selectively detachable electrical connector assemblies provide for signal and guard connections to the first and second chuck assembly elements, respectively, as well as providing Kelvin connections thereto. The capacitance between the respective chuck assembly elements is extremely low due to the provision of air space as the primary electrical insulator.

Abstract: A wafer probe station is equipped with a compact, integrated controlled-environment enclosure providing EMI shielding, substantially hermetic sealing for a dry purge gas for low-temperature testing, and a dark environment. The sealing isolation of the wafer chuck and test probe provided by the enclosure is maintained despite the fact that the probe and chuck positioning mechanisms extend partially outside the enclosure, with positioning members extending movably between the interior and exterior of the enclosure. Sealing is maintained by movable sealing members at the locations where the positioning members penetrate the enclosure.

Abstract: A wafer probe station has a wafer-supporting vacuum chuck, together with one or more substrate-supporting auxiliary vacuum chucks having independent vacuum controls for mounting contact substrates and calibration substrates simultaneously with the wafer. A detachable interconnection of the various chucks enables independent replacement of each chuck to accommodate various different chuck types, and also permits the elevations of the respective chuck surfaces to be adjusted relative to each other to compensate for differences in thicknesses between the wafer substrate and the calibration or contact substrates. The invention is especially useful in wafer probe stations equipped with enclosures for controlled-environment testing where a large variety of different wafer chucks must be readily interchangeable for testing under different conditions.