Electron microscope and method of adjusting focus of electron microscope
US11670479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 2021 |
| Grant date | Jun 6, 2023 |
| Priority date | — |
| Expiry date | Nov 27, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/216
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
When focus adjustment is performed according to the height of the surface of a sample at each inspection point in order to continuously inspect a plurality of inspection points on a wafer by using an electron microscope, even when the focus adjustment by an electrostatic lens in which a variation of heights of inspection points is greater than a predetermined range, and that can perform adjustment at a high speed and adjustment by an electromagnetic lens with a low speed are required to be used together, a flow of focus adjustment in which the number of times of the adjustment by the electromagnetic lens is reduced by using a relation of changes of heights at inspection points, an inspection order, and a range in which an electrostatic focus can be performed is realized, so that inspection with high throughput is made possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.