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:
Sep. 15, 2009
Filed:
Sep. 27, 2006
Arun Ananth Aiyer, Lewisville, TX (US);
Mark A. Meloni, Longmont, CO (US);
Arun Ananth Aiyer, Lewisville, TX (US);
Mark A. Meloni, Longmont, CO (US);
Verity Instruments, Inc., Carrollton, TX (US);
Abstract
A self referencing heterodyne reflectometer is disclosed which rapidly alternates between a heterodyne reflectometry (HR) mode, in which an HR beam comprised of s- and p-polarized beam components at split angular frequencies of ω and ω+Δω is employed, and a self referencing (SR) mode, in which an SR beam comprised of p-polarized beam components at split angular frequencies of ω and ω+Δω is employed. Alternatively, in SR operating mode the SR beam is replaced by a p-polarized amplitude modulated (AM) beam, operating at two modulated amplitudes of α and α+Δα at a single frequency, ω'. When the two measurements are made in rapid succession, using an optical chopper switcher, temperature induced noise in the detector is be assumed to be equivalent. Film phase shift information is derived from the measured phase shift δ, generated from the HR beam, and the reference phase shift δ, generated from the SR/AM beam, which are used for calculating film thickness.