The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 03, 1995
Filed:
Jun. 17, 1992
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
An apparatus for non-destructively measuring resistivity of a semiconductor, such as InP, comprises light sources for illuminating a preselected portion of the semiconductor with first and second light beams, each of a preselected single wavelength, the first light beam operating to excite the semiconductor by photo injecting carriers, and the second light beam bombarding the local portion of the semiconductor with a preselected photon energy. The apparatus measures a fractional change in reflectance of the second light beam responsive to the first light beam, and records this fractional change in reflectance for various values of photon energy of the second light beam, to generate a photoreflectance line-shape. The photoreflectance line-shape is used to calculate a photoreflectance line-shape phase angle, which is used to determine the resistivity of the preselected portion of the semiconductor.