Variation-free baseline with p-polarized Brewster incidence for infrared measurement of carbon impurities in silicon wafer

摘要

In our previous infrared transmission study, the baseline variation [H. Saito and H. Shirai, J. Electrochem. Soc. 147, 1210 (2000)] appeared near the carbon impurity band at 605cm(-1) in the normal incidence infrared spectra of silicon, This occurs because of the diminishing of multiple reflections due to the strong two-phonon absorption in the range of 610-630 cm(-1) and the difference in resistivity between the test and reference samples. To solve the problem of baseline variations, p-polarized Brewster incidence has been successfully applied to infrared measurements of carbon impurities in wafer-thick silicon samples. No baseline variations have appeared in this range, owing to the absence of multiple reflections. (C) 2018 The Japan Society of Applied Physics