Regular papers

A fast inversion method for highly conductive submicron wires on a substrate

¹ Dept. of Process and Chemical Engineering, University of Bremen, Badgasteiner Str. 3, 28359 Bremen, Germany
² Danish Fundamental Metrology, Technical University of Denmark, Matematiktorvet 307, DK-2800 Kgs. Lyngby, Denmark

^a mirza@iwt.uni-bremen.de
^b peh@dfm.dtu.dk
^c thw@iwt.uni-bremen.de

Received: 24 February 2011

Abstract

A numerical method is presented for sizing of highly conductive penetrable and perfectly electrically conducting (PEC) submicron wires on substrates. For efficiency, the Method of Auxiliary Sources is used in the forward model of the inverse Kirsch-Kress Method. The radius of the circular cross section of PEC and silver wires positioned on a semi-infinite silicon substrate is estimated based on numerically simulated scattered far field. The illumination is monochromatic, transverse electric (TE) polarised, and with fixed angle of incidence. Average relative errors smaller than 1% and 5% are achieved for PEC and penetrable wires, respectively, in the dynamic ranges 0.2–1.3 and 0.8–1.3 times the operating free-space wavelength, respectively. In all cases, the inversion time is less than 1 sec.