Apparatus and method for suppressing electrification of sample in charged beam irradiation apparatus
US5466929A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1993 |
| Grant date | Nov 14, 1995 |
| Priority date | — |
| Expiry date | Feb 22, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3175
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
When a charged beam is irradiated on a sample, charge up of electric charge of the same polarity as that of the charged beam is built up on the sample surface. In order to neutralize the charge up electric charge, an apparatus for suppressing electrification of sample in charged beam irradiation apparatus is provided in which electric charge of opposite polarity to that of the charged beam is generated near the sample surface to neutralize the charged beam or charge up electric charge on the sample surface. The electric charge for neutralization is generated by admitting elecrtic charge from a plasma generation unit to the vicinity of the sample surface, ionizing gas generated from the sample surface by causing the charged beam to collide the gas or by irradiating electrons from an electron source on the sample surface. Especially when there is a possibility that impurities other than the electric charge for neutralization affect the sample adversely, an impurity generation source is blind folded with a cover so as not to be seen through from the sample and charged beam so that the impurities may be prevented from impinging upon the sample surface or intersecting the charged beam p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.