Electrical probing of deep sub-micron ICs using scanning probes

Abstract

A contact electrical probe for imaging and real-time signal measurement of deep sub-micron integrated circuits is presented. Similar to wire probers, the probe operates on a standard probe-station, but utilizes a conductive atomic force microscope micromachined tip to rapidly measure surface topography and acquire real-time high-frequency signals. The probe scanning system enables imaging and placement on features as small as 0.18 micron and is able to control and maintain the contact force to less than 50 nanonewton, thus minimizing circuit damage. The probe tip incorporates active electronics near the tip enabling 300 MHz bandwidth measurements while presenting a high impedance load, less than 120 fF, to the device being measured. Measurements of 0.25 /spl mu/m interconnects and polished devices is presented.