Inspection apparatus incorporating digital electron detection
US4985628A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1988 |
| Grant date | Jan 15, 1991 |
| Priority date | — |
| Expiry date | Nov 29, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/305
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inspection apparatus which incorporates a digital electron detection device. In this apparatus, counting devices are used for the measurement of electrons emanating from an object after interaction with an incident radiation beam. Using these counters, detection is also possible even when the electron pulses have a small current content. By the addition of a DAC and possibly a sample-and-hold circuit, spectometric measurements are possible so that absolute potential values of a measuring point can be determined. For measurement of comparatively large currents, digital feedback can be used. Multi-sampling make possible much faster measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.