Accession Number:

ADD014950

Title:

Micro Photoreflectance Semiconductor Wafer Analyzer.

Descriptive Note:

Patent Application, Filed 21 Dec 90,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

Report Date:

1990-12-21

Pagination or Media Count:

22.0

Abstract:

An apparatus for measuring local carrier concentration in a preselected area of a semi-conductor is shown and described. An exciting light preferably a laser alters the samples band-gap by photo injecting electron hole pairs in the area being measured. Because of the Franz-Keldysh effect, the photo injected carriers alter the samples reflectivity. An optical fiber conducts a broad band source of probing light to the excited area on the sample. The sample reflects some of the broad band light back into a fiber that conducts the reflected light to an optical analyzer. The optical analyzer includes a dispersive element that disperses the reflected light onto a linear array of detectors. The analyzer thus simultaneously samples multiple wavelengths in the reflected spectrum. From the resulting samples, a computer deconvolutes the spectral line shape into a measurement of the local electric field and the local carrier concentration. Author

Subject Categories:

  • Solid State Physics
  • Test Facilities, Equipment and Methods
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE