English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

concentration and lattice absorption in bulk and epitaxial silicon carbide determined using infrared ellipsometry" We have measured the dielectric function of bulk nitrogen-doped 4H and 6H SiC substrates from 700 to 4000 cm Ϫ1 using Fourier-transform infrared spectroscopic ellipsometry. Photon absorption by transverse optical phonons produces a strong reststrahlen band between 797 and 1000 cm Ϫ1 with the effects of phonon anisotropy being observed in the region of the longitudinal phonon energy ͑960 to 100 cm Ϫ1 ͒. The shape of this band is influenced by plasma oscillations of free electrons, which we describe with a classical Drude equation. For the 6H-SiC samples, we modify the Drude equation to account for the strong effective mass anisotropy. Detailed numerical regression analysis yields the free-electron concentrations, which range from 7ϫ10 17 to 10 19 cm Ϫ3 , in good agreement with electrical and secondary ion mass spectrometry measurements. Finally, we observe the Berreman effect near the longitudinal optical phonon energy in nϪ/nϩ homoepitaxial 4H SiC and hydrogen implanted samples, and we are able to determine the thickness of these surface layers.

Carrier concentration and lattice absorption in bulk and epitaxial silicon carbide determined using infrared ellipsometry