Cyclotron Resonance in Space Charge Layers on Si

Abstract

Cyclotron resonance of electrons bound in quantized states in space charge layers on a (100) surface of Si has been observed. We have seen the electron resonance in both inversion and accumulation layers. For the case of inversion the cyclotron mass mc* is found to differ substantially from the bulk value 0.1905 m0 and to vary with the surface density of electrons (Qs). We find mc*=0.230 m0 for Qs≈0.2 ×1012 electrons/cm2, which decreases to mc*=0.230 m0 for Qs ≈2.0×1012 electrons/cm2. The relaxation time from cyclotron resonance exhibits a maximum near Qs≈0.8×1012 electrons/cm2 for the inversion layer. In recent work* we have discovered in addition to the fundamental resonance an approximately subharmonic sequence of peaks, which we attribute to cyclotron resonance perturbed by charged trap states at the Si–SiO2 interface. We also find cyclotron resonance of electrons in an accumulation layer on n-type (100) Si with mass mc* close to the bulk value.