Charged particle beam scanning type automatic inspecting apparatus
US6538248B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1999 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Sep 17, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2817
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In order that the deflection scanning position can be corrected at a time point within a period for fetching information from a subject to be inspected and improvements in accuracy of chip comparison inspection and an inspection near the wafer outer periphery where distortion is large can be assured by correcting the inspection position and biased distortion at a high speed with high accuracy, a digital deflection control scheme is employed in which the deflection scanning signal and correction are all calculated digitally in a deflection controller for deflecting and controlling a charged particle beam irradiated onto a subject to be inspected and the digital value is sequentially converted into an analog value by a time-series train of digital control signal to form a deflection scanning waveform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.