High-field cyclotron resonance and impurity transition inn-type andp-type 3C-SiC at magnetic fields up to 175 T

Abstract

Magnetotransmission experiments have been carried out on 3C-SiC thin films grown on Si(100) substrates, using the combination of pulsed high magnetic fields up to 175 T generated by the single-turn coil technique and pulsed far-infrared radiations from a ${\mathrm{H}}_2$O (${\mathrm{D}}_2$O) laser at photon energies up to 73.2 meV. In n-type 3C-SiC, two cyclotron-resonance (CR) peaks have been observed for B∥k∥〈100〉 over a wide range of photon energy 10.4–53.8 meV, corresponding to the light- and heavy-mass valleys at the X points, i.e., ${\mathit{m}}_{\mathit{t}}^{\mathrm{*}}$=(0.25±0.01)${\mathit{m}}_0$ and (${\mathit{m}}_{\mathit{t}}^{\mathrm{*}}$ ${\mathit{m}}_{\mathit{l}}^{\mathrm{*}}$ ${)}^{1/2}$=(0.41±0.01)${\mathit{m}}_0$. These values are in agreement with those of Kaplan et al. obtained from CR at low fields. This leads to the conclusion that the conduction band in 3C-SiC is very parabolic up to 53.8 meV, and that unlike GaP the effect of camel’s-back structure is unobservable. A number of impurity transitions were observed at temperatures below 100 K with photon energies ranging from 34.4 to 73.2 meV. It was found that the observed lines originate from three different donor states which have different binding energies, ${\mathit{E}}_{\mathit{d}}$=19, 35, and 53 meV. The observation of hole CR was also made in p-type 3C-SiC. A broad but prominent peak was observed with an effective mass of 0.45${\mathit{m}}_0$, at temperatures around 210 K and at a wavelength of 119 μm.