Patent · US Expired

Contactless total charge measurement with corona

US6448804B2 · kind B2 · utility

2Cited by
9References
2Claims
0Family size

Inventors

Key dates

Filing dateSep 27, 2001
Grant dateSep 10, 2002
Priority date
Expiry dateSep 27, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/2831
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method of measuring total charge of an insulating layer on a semiconductor substrate includes applying corona charges to the insulating layer, and measuring a surface photovoltage of the insulating layer after applying each of the corona charges. The charge density of each of the corona charges is measured with a coulombmeter. A total corona charge required to obtain a surface photovoltage of a predetermined fixed value is determined and used to calculate the total charge of the insulating layer. The fixed value corresponds to either a flatband or midband condition.

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