High brightness liquid droplet X-ray source for semiconductor metrology
US9693439B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2014 |
| Grant date | Jun 27, 2017 |
| Priority date | — |
| Expiry date | Dec 26, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2235/082
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and systems for realizing a high brightness liquid metal droplet based x-ray source suitable for high throughput x-ray metrology are presented herein. A high power laser bombards a solid target material to generate liquid metal droplets. The laser generated liquid metal droplets are excited with a focused, high power excitation beam such as an electron or laser beam. The excitation beam is synchronized with the stream of liquid metal droplets stimulated by the high power laser to achieve a stable x-ray emission generated by the excited liquid metal droplets. In some embodiments, x-ray optics are designed to efficiently collect and focus radiation within a desired emission band onto a measurement target. Reliability is improved by shielding the excitation source and the x-ray optics from the region of interaction between the excitation beam and the liquid metal droplet anode by a localized curtain of shielding gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.