APPLICATION OF IR VARIABLE-ANGLE SPECTROSCOPIC ELLIPSOMETRY TO THE DETERMINATION OF FREE-CARRIER CONCENTRATION DEPTH PROFILES

Free carrier concentration profiles were determined by Fourier Transfo rm Infrared (FTIR) variable angle spectroscopic ellipsometry. The tech nique exploits carrier absorption in the mid-infrared spectral range a nd combines the sensitivity of ellipsometry with a simple Drude free c arrier absorption model to determine the carrier profile. In this stud y, the carrier profiles were modeled as graded multilayers that were c onstrained to a specific functional form (e.g. Gaussian. complementary error function) when appropriate. Carrier profiles from boron and ars enic ion-implanted that had been subjected to furnace or Rapid Thermal Annealing (RTA) annealed silicon wafers were compared to Spreading Re sistance Probe and Secondary Ion Mass Spectrometry profiles. p - p + d oped epitaxial silicon samples (before and after annealing) were also measured and the results were compared to theory. (C) 1998 Elsevier Sc ience S.A.