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:
Nov. 15, 1994
Filed:
Dec. 21, 1990
Nicholas Bottka, Burke, VA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
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 sample's 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 sample's 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.