Electron, charge particle or laser beam system e.g. for testing integrated circuit on large substrate - has deflection system for primary beam through aperture slot of extraction electrode, and detector for sensing fraction of secondary electrons generated from surface of test object

摘要

A substrate (SUB) mounted on a moving table (T) has measurement points (M) on its side remote from the table. The instrument consists of a deflection unit (A) provided for a primary beam (PE), an electrode (AE) with at least one slotted aperture (SP), and a detector (D) for the secondary electrons (SE) generated by the beam. The primary beam is directed by the deflection unit through the aperture and onto the measurement points on the substrate. Some of the secondary electrons released by the primary beam and passing through the aperture are detected by the detector. ADVANTAGE - Enables potential measurement with high positional and potential resolution even for large area substrates, achieving suppression of local disturbance fields.