The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 02, 1986
Filed:
Jan. 22, 1985
Applicant:
Inventors:
Lawrence K White, W. Windsor Township, Mercer County, NJ (US);
Jen-shen Maa, Plainsboro Township, Mercer County, NJ (US);
Assignee:
RCA Corporation, Princeton, NJ (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
2041 / ; 156626 ; 156643 ; 156662 ;
Abstract
A method of determining the presence of alkali metal ions in a substrate comprising silicon or silicon doped with a p-type conductivity modifier is provided. The substrate to be tested is etched in a tetrafluoromethane/oxygen plasma and the etch rate is compared against that of similar substrates containing known concentrations of alkali metal ions. The etch rate will increase with increasing alkali metal concentration. The subject method is particularly useful in determining the level of alkali metal ion contamination during multistep processing of the above-named substrates.