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:
Mar. 06, 2001
Filed:
Jul. 01, 1998
Maria Luisa Polignano, Cambiago, IT;
Marzio Brambilla, Robbiate, IT;
Francesco Cazzaniga, Seveso, IT;
Giuseppe Pavia, Brescia, IT;
Federica Zanderigo, Padua, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
The depth of a denuded layer with respect to a relatively defective bulk region of a monocrystalline semiconductor wafer is estimated in a nondestructive way. The depth is determined by measuring the lifetime or diffusion length of injected excess minority charge carriers on a surface of the wafer having such a denuded layer and on a different portion of the surface of the wafer from where the denuded layer has been previously stripped-off by lapping and/or etching. The depth is calculated through a best-fit procedure or through numerical processing of the measurement results on the basis of the diffusion equations of excess minority carriers.