In-situ method for real time monitoring of chemical baths for transition metals with multi-channel electrodes
US6225135A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1999 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | May 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/26
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention provides an electrolytic cell for use in a process for real time monitoring of a chemical bath used in the fabrication of a semiconductor wafer and having different metal ions therein. In one embodiment, the electrolytic cell comprises a fluid chamber having an inlet, an outlet and chamber walls, and channel electrodes coupled to the chamber walls. The inlet and outlet permit a throughflow of at least of a portion of the chemical bath. Each of the channel electrodes corresponds to one of the different metal ions. Each channel electrode is energized to a detection potential selected to provide electrical conduction when the corresponding different metal ion reaches a prescribed concentration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.