Patent · US Expired

Apparatus and method for making surface photovoltage measurements of a semiconductor

US5087876A · kind A · utility

30Cited by
3References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 16, 1990
Grant dateFeb 11, 1992
Priority date—
Expiry dateJul 16, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/308
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An apparatus for making ac surface photovoltage (SPV) measurements of a specimen of semiconductor material under variable dc bias voltage conditions includes a light source whose output beam is intensity modulated, a reference electrode, a guard electrode, a back electrode, a first voltage for biasing the reference electrode with a variable dc voltage and a second voltage separate from the first voltage for biasing the guard electrode such that an accumulation layer is established in the area on the specimen controlled by the guard electrode to prevent flow of carriers between the area controlled by the reference electrode and the rest of the specimen.

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