Etching method and etching apparatus
US6780277B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2002 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Mar 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31111
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An etching method and an etching apparatus are provided. Silicon (Si) from surfaces semiconductor wafers W dissolves into an etching liquid E stored in a process bath 10. On detection of the concentration of silicon by a concentration sensor 50, the etching liquid E in the process bath 10 is discharged while leaving a part of the etching liquid when the Si concentration in the etching liquid E reaches a designated concentration. After that, a new etching liquid of substantially equal to an amount of the discharged etching liquid E is supplied into the process bath 10 and added to the etching liquid remaining in the bath 10. Consequently, it is possible to restrict the etching rate just after the exchange of etching liquid from rising excessively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.