6H-SiC epilayers as nuclear particle detectors

Schottky diodes based on the n-n(+) 6H-SiC epilayers grown by sublimation epitaxy and also the layers produced by CREE company (USA) were used as detectors of alpha-particles of spontaneous decay. Since the thickness of n-layers was smaller than the range of the particles, geometrical parameters of the experiment differed from conventional ones; in the latter case, a particle is brought to rest in the region of electric field in the detector. The calculated and experimental data were compared to study the special features of transport of nonequilibrium charge under the conditions of complete and partial depletion of the structure. It is shown that characteristics of the material that govern the transport of charge carriers can be deduced from the analysis of the behavior of the signal amplitude and the shape of the pulse-height spectrum in relation to bias voltage applied to the Schottky diode. It follows from the results that the present-day sublimation-grown SiC layers are suitable for use as the basis for fabrication of nuclear particle detectors. (C) 2000 MAIK "Nauka/Interperiodica".