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:
Apr. 12, 1994
Filed:
Sep. 25, 1992
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
Spatial distribution of deep level concentration near the surface of a semiconductor wafer is evaluated quickly and accurately by a method which comprises at least a step of scanning the surface of the semiconductor wafer in the X and Y direction with a laser beam for carrier excitation from a laster beam source in accordance with the room-temperature photoluminescence (PL) process thereby measuring the wafer map (M.sub.D) of deep level PL intensity (I.sub.D) and wafer map (M.sub.B) of band edge PL intensity (I.sub.B) in the semiconductor wafer and a step of dividing the wafer map (M.sub.D) of PL intensity (I.sub.D) by the .nu.'th power of the wafer map (M.sub.B) of PL intensity (I.sub.B) {the magnitude of the .nu.'th power presenting the numerical value obtained by empirically confirming the dependence of the band edge PL intensity (I.sub.B) on the power of the excitation laster mean} thereby determining the spatial distribution (M.sub.N) of the relative value of deep level concentration (N.sub.D) and performing the evaluation of the distribution of relative deep level concentration on the basis of the spatial distribution (M.sub.N) of the relative deep level concentration (N.sub.D).