Patent · US Expired

Apparatus for measuring the life time of minority carriers of a semiconductor wafer

US5438276A · kind A · utility

5Cited by
5References
13Claims
0Family size

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Key dates

Filing dateMay 12, 1993
Grant dateAug 1, 1995
Priority date
Expiry dateMay 12, 2013

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/2656
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An apparatus for measuring the life time of minority carriers includes a light source for irradiating a first region of a semiconductor wafer, a microwave generator for generating microwaves, a transmission line for transmitting a first part of the generated mark raised to the region of the semiconductor wafer that is radiated by the excitation light and a second portion of the generated microwave to a region of the semiconductor wafer that is not radiated by the excitation light. The intensity of the microwave signals reflected from the semiconductor wafer are detected and the life time of the minority carriers is calculated based upon the detected intensities.

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