Global Patent Index - EP 2792788 B8

EP 2792788 B8 20160921 - Process for extracting dominant spectral components from a power spectrum of noisy measurements

Title (en)

Process for extracting dominant spectral components from a power spectrum of noisy measurements

Title (de)

Verfahren zum Gewinnen dominanter Spektralanteile aus einem Lesitungspektrum von Rauschmessungen

Title (fr)

Procédé pour l'extraction des composante spectrales dominantes d'un spectre de puissance de mesures bruyantes.

Publication

EP 2792788 B8 20160921 (EN)

Application

EP 14171182 A 20120427

Priority

  • US 201161480249 P 20110428
  • EP 12723551 A 20120427

Abstract (en)

[origin: US2012278032A1] CD variations and/or MD variations in scan measurements are determined from spectral components of power spectra of scan measurements taken using two or more scanning speeds. Dominant spectral components having the same spatial frequencies identify CD variations and dominant spectral components having the same temporal frequencies identify MD variations. Dominant spectral components are extracted from a noisy power spectrum (PS) by sorting all spectral components into an ordered PS. A first polynomial representing background noise of the ordered PS is used to set a first threshold. Spectral components of the ordered PS that exceed the first threshold are removed to form a noise PS. A second polynomial representing the noise PS is used to set a second threshold. Spectral components of the PS that exceed the second threshold are identified as dominant spectral components of the PS.

IPC 8 full level

D21G 9/00 (2006.01); G01N 21/86 (2006.01); G01N 21/89 (2006.01); G01N 33/18 (2006.01); G01N 33/34 (2006.01)

CPC (source: CN EP US)

D21G 9/0009 (2013.01 - CN EP US); G01N 21/86 (2013.01 - CN EP US); G01N 33/346 (2013.01 - CN EP US); G01N 21/8901 (2013.01 - CN EP US)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DOCDB simple family (publication)

US 2012278032 A1 20121101; US 9783929 B2 20171010; CN 103620113 A 20140305; CN 103620113 B 20151223; CN 104878643 A 20150902; CN 104878643 B 20170412; EP 2702204 A2 20140305; EP 2702204 B1 20160720; EP 2702204 B8 20160921; EP 2792788 A2 20141022; EP 2792788 A3 20141105; EP 2792788 B1 20160727; EP 2792788 B8 20160921; US 2018073196 A1 20180315; WO 2012149269 A2 20121101; WO 2012149269 A3 20121220

DOCDB simple family (application)

US 201213457870 A 20120427; CN 201280028248 A 20120427; CN 201510272476 A 20120427; EP 12723551 A 20120427; EP 14171182 A 20120427; US 2012035385 W 20120427; US 201715718529 A 20170928