Characterization of delta-doped GaAs grown by molecular beam epitaxy

The resolution of the capacitance-voltage (C-V) technique on single- and multi-/spl delta/-doped GaAs is shown to be given by the breadth of dopant distribution. The experimental C-V profiles demonstrate that impurities are spatially localized on the length scale of the lattice constant. We present a technique of sample profiling by Raman spectroscopy with no depth limitation. It is based on the evaluation of the ratio of intensities of transverse and longitudinal optical phonons along a semiconductor-bevelled surface. Furthermore, the sharp distribution of dopants is assessed by the secondary-ion mass spectroscopy. The obtained results, the /spl delta/-doped layer location and spatial extent of dopants, are in agreement even though the measurements are probing different aspects.