Patent · US Expired

Method of detecting a thin insulating film over a conductor

US4296370A · kind A · utility

3Cited by
1References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 11, 1979
Grant dateOct 20, 1981
Priority date
Expiry dateOct 11, 1999

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/316
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method of detecting the presence of a thin insulating film having a thickness less than about 500 angstroms disposed over a surface of a conductor comprises positioning a conductive grid adjacent the surface of the insulating film. Ions of one type polarity are deposited adjacent the insulating film through openings in the grid, the openings in the grid being sufficiently small to limit the surface charge voltage on the insulating film to less than about 50 volts. After immersing the insulating film in a suspension of charged particles having a polarity opposite to the one type, the deposition of charged particles adjacent the conductor surface then indicates the presence of the insulating film.

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