6H(n~+)/3C(n)/6H(p~+) - SiC Structures Grown by Sublimation Epitaxy

摘要

Investigation of the multilayer 6H(n~+)/3C(n)/6H(p~+)-SiC heterostructure grown by sublimation epitaxy show that the injection electroluminescence (IEL) in the green region (hν_(max)≈2.30-2.35eV) of spectrum is dominant. This band is close to the electroluminescence peak due to defects in 6H-SiC but also can be due to free exciton annihilation in a quantum well in 3C-SiC at the 6H/3C-SiC heterointerface. At high current the IEL peak at hν_(max)≈2.9 eV is found. This peak (and also two another peaks in blue part of spectra: hν_(max)≈2.6 eV and hν_(max)≈2.72 eV) can be attributed to recombination in 6H-SiC. The forward current-voltage characteristics for best structures are close to those for ideal 6H-SiC pn homostructure and characterized by abrupt breakdown. A lot of structures are characterized by barrier type excess current. Structure in the region of evident 3C-SiC inclusion is characterized by high forward and reverse excess currents.