Study of charge collection efficiency in 4H-SiC Schottky diodes with~(12)C ions~*

摘要

The Charge Collection Efficiency (CCE) in 4H-SiC epitaxial Schottky diodes is studied as a function of theapplied reverse bias. Three SiC types, with different doping concentrations, were used to detect ~(12)Cionsat 14.2, 28A and 37.6 MeV. In two SiC types we observe minority charge carriers, generated by theincoming ion in the neutral region, which diffuse to the depleted layer and are finally collected. Theminority carriers contribution to the CCE is well reproduced by an analytical equation which representsthe contribution from the charge carriers diffusing to the depletion region from the semiconductorsubstrate. From a best fit procedure, the minority carriers diffusion length is extracted and the minoritycarriers lifetime is calculated. Finally, the dependence of the lifetime on the doping concentration isinvestigated.