DETERMINATION OF THE ELECTRON EFFECTIVE-MASS TENSOR IN 4H SIC

Experimental and theoretical results from studies of electron effectiv e masses in 4H SiC are presented. Three principal values of the mass t ensor are experimentally resolved by optical detection of cyclotron re sonance, and are determined as m (ML) = 0.33 +/- 0.01m(0), m(MT) = 0.5 8 +/- 0.01m(0), and m (MK) = 0.31 +/- 0.01m(0). These values are in go od agreement with m (ML) = 0.31 m(0), m (MT) = 0.57m(0), and m (MK) = 0.28m(0), obtained from band-structure calculations based on the local density approximation to the density-functional theory using the line arized augmented plane-wave method. The conduction-band minimum is fou nd to be at the M point of the Brillouin zone.