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:
Jul. 15, 2008
Filed:
Nov. 01, 2002
Andrew J. Perry, Fremont, CA (US);
Vijayakumar C. Venugopal, Berkeley, CA (US);
Andrew J. Perry, Fremont, CA (US);
Vijayakumar C. Venugopal, Berkeley, CA (US);
Lam Research Corporation, Fremont, CA (US);
Abstract
A method of controlling a recess etch process for a multilayered substrate having a trench therein and a column of material deposited in the trench includes determining a first dimension from a surface of the substrate to a reference point in the substrate by obtaining a measured net reflectance of at least a portion of the substrate including the trench, computing a modeled net reflectance of the portion of the substrate as a weighted incoherent sum of reflectances from n≧1 different regions constituting the portion of the substrate, determining a set of parameters that provides a close match between the measured net reflectance and the modeled net reflectance, and extracting the first dimension from the set of parameters; computing an endpoint of the process as a function of the first dimension and a desired recess depth measured from the reference point; and etching down from a surface of the column of material until the endpoint is reached.