Patent · US Active

Etchant product analysis in alkaline etchant solutions

US9274079B2 · kind B2 · utility

1Cited by

1References

14Claims

0Family size

Assignee

ECI TECHNOLOGY, INC.

Inventors

Eugene Shalyt · Hackettstown, US
Guang Liang · Elmhurst, US
Peter Bratin · Great Neck, US

Key dates

Filing date	Jul 15, 2013
Grant date	Mar 1, 2016
Priority date	—
Expiry date	Jul 4, 2034

Classification

Technology area (CPC G)Physics
CPC primaryG01N27/4166
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

Silicon ions in an alkaline etchant solution are analyzed by acidifying a sample of the etchant solution, adding fluoride ions in excess of the concentration required to react with all of the silicon ions, and using a fluoride ion specific electrode (FISE) to detect free fluoride ions in the resulting test solution. Good sensitivity and precision are provided by using a relatively acidic test solution and only a slight excess of fluoride ions, and limiting the analysis range to the maximum expected silicon concentration in the etchant solution.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.