Method of measuring negative ion density of plasma and plasma processing method and apparatus for carrying out the same
US6452400B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2000 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Dec 1, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/0081
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A probe (6) is brought into contact with a plasma produced by ionizing Ar gas, a saturation current (Ies2) at which current flowing through the probe is saturated when the potential of the probe is changed in a potential region where the potential of the probe is higher than a ground potential, and a saturation current (Iis2) at which current flowing through the probe is saturated when the potential of the probe is changed in a potential region where the potential of the probe is lower than the ground potential. Similarly, saturation currents (Ies2, Iis2) are measured by bringing the probe (6) into contact with a plasma produced by ionizing a mixed gas containing Ar gas and a process gas, such as C4F8 gas, and changing the potential of the probe (6). The negative ion density of the plasma produced by ionizing C4F8 gas is determined by using saturation current ratios (Iis1/Iis2, Ies1/Ies2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.