Patent · US Expired

Mobile charge measurement using corona charge and ultraviolet light

US5834941A · kind A · utility

59Cited by
5References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 11, 1997
Grant dateNov 10, 1998
Priority date
Expiry dateAug 11, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L22/14
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Corona charge is applied to an oxide layer on a semiconductor wafer. Then ultraviolet light is used to erase a grid pattern of the corona charge. Opposite polarity corona charge is then applied to the layer, resulting in a grid of field-induced PN junctions. The surface photovoltage of the junctions is measured over time to provide a measure of the mobile charge in the oxide layer.

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