Ion implantation beam monitor
US6646276B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2001 |
| Grant date | Nov 11, 2003 |
| Priority date | — |
| Expiry date | Aug 2, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31703
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
As a rotating spoked substrate wheel passes across a beam stop during a scan cycle, a series of pulses are generated by the beam stop. These pulses are analysed to determine characteristics about the ion bam in an implanter.A digital signal processor (DSP) samples the beam stop current at regular intervals. By comparing the magnitude of successive samples, a dose uniformity map may be generated, so that identification of particular substrates on the wheel which have been dosed incorrectly is possible.The time taken for the beam to move between two points during the scan can also be measured from the sampled beam stop current. This provides a measurement of ion beam width. Similarly, by measuring, from the sample beam stop current, the time taken for the ion beam to pass between the middle of two adjacent substrates, the beam height may be ascertained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.