Optical Constants of Epitaxial Silicon in the Region 1–3.3 eV

The optical constants of epitaxial silicon have been obtained in the region 1–3.3 eV (to 3.1 eV for n ) by means of optical transmission and photoconductivity measurements. The silicon layers are 0.1–3 μm thick and therefore give interference spectra in both measuring modes. The values of n obtained here fit well with those obtained from reflectance and ellipsometric measurements on bulk silicon. The absorption coefficient α is calculated from the quotient I Tu / I T1 , where I Tu(1) is the upper (lower) envelope of the transmitted intensity interference curve. The values obtained here are greater by a factor of 2 than those of Dash & Newman (1955). Literature values obtained from ellipsometric measurements at λ = 5 461 Å show a substantial spread with the values of Dash & Newman as a lower limit.