Inspection system and apparatus

Method for identifying a defect or contamination on the surface of the sample and system are provided. The system operates by detecting changes in the crossing through both the work function across the surface, and nvCPD vCPD. Ratio for imaging the work function trend throughout the sample-vibrating contact potential difference uses (nvCPD) sensor. The data is differential, this indicates a change in work function across the sample surface (or geometric shape, or surface voltage). vCPD probe is used to determine the absolute CPD data for a particular point on the surface of the sample. Vibrating CPD and the non-vibrating CPD measurement mode by combining, for rapid imaging of the entire sample becomes possible, it becomes possible to detect an absolute work function of at least one point.