US 9,812,287 B2
Charged particle microscope with improved spectroscopic functionality
Cornelis Sander Kooijman, Veldhoven (NL); Thijs Thomas Withaar, Eindhoven (NL); and Gerard Nicolaas Anne van Veen, Waalre (NL)
Assigned to FEI Company, Hillsboro, OR (US)
Filed by FEI Company, Hillsboro, OR (US)
Filed on Dec. 29, 2015, as Appl. No. 14/983,038.
Claims priority of application No. 14200596 (EP), filed on Dec. 30, 2014.
Prior Publication US 2016/0189922 A1, Jun. 30, 2016
Int. Cl. H01J 37/244 (2006.01); H01J 37/285 (2006.01); G01N 23/223 (2006.01); G01N 23/225 (2006.01)
CPC H01J 37/244 (2013.01) [G01N 23/223 (2013.01); G01N 23/2252 (2013.01); G01N 23/2257 (2013.01); H01J 37/285 (2013.01); G01N 2223/501 (2013.01); H01J 2237/2445 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of examining a specimen using a spectroscopic apparatus, comprising the following steps:
providing the specimen on a specimen holder;
directing a focused input beam of radiation onto a location P on the specimen, thereby producing an interaction that causes a flux of X-rays to emanate from said location;
examining said flux using a detector arrangement, thus accruing a measured spectrum for said location;
choosing a set of different measurement directions d={dn} that originate from P, where n is a member of an integer sequence;
recording an output On of said detector arrangement for different values of dn, thus compiling a measurement set M={(On, dn)};
adopting a spectral model On′ for On that is a convoluted mix of terms B(dn) and Lp, where:
B(dn) is a substantially continuous spectral component associated with Bremsstrahlung;
LP is a substantially discrete spectral component associated with the composition of the specimen at location P;
automatically deconvolving the measurement set M on the basis of said spectral model On′ and distill Lp therefrom, wherein spectral model On′ is expressed in the form:
On′=A(dn)*R(dn)
R(dn)=[Lp+B(dn)]
in which A(dn) is an absorption function, accounting for the dependence of x-ray absorption as a function of the path length within the specimen, * is a mathematical convolution and R(dn) is a radiation function comprising the types of x-ray emitted from the specimen.