Measurement speed and resolution of surface voltage based non-visual defect inspection are examined. There is a tradeoff between high measurement speed in whole wafer inspection which requires a larger measurement probe and resolution of the method which requires a smaller measurement probe. In this paper we overcome this tradeoff by using different diameter Kelvin probes. Full wafer inspection is performed using a 2mm diameter Kelvin probe enabling high throughput. Only when a suspected failure is detected, an inspection of a localized smaller area is performed with a 10 μm diameter Kelvin probe.
