RT Journal Article T1 Structural characterization of 6H-and 4H-SiC polytypes by means of cathodoluminescence and x-ray topography A1 Rodríguez Fernández, José A1 Carcelen, V. A1 Hidalgo Alcalde, Pedro A1 Vijayan, N. A1 Piqueras De Noriega, Francisco Javier A1 Sochinskii, N. V. A1 Pérez, J. M. A1 Diéguez, E. AB The cathodoluminescence (CL) technique is used to analyse the radiative recombination properties of four distinct silicon carbide (SiC) samples: a 6H-SiC n^+ -type Lely wafer, two off-axis 4H-SiC epitaxial layers of n type and p type, and a (11 (2) over bar0)-oriented 4H-SiC n^+-type substrate. The CL spectra, recorded at various temperatures and at various excitation conditions, show strong differences between the polytypes, indicating a better homogeneous distribution of radiative centres inside the 6H polytype than in the 4H one, and also between the different orientations. For the (11 (2) over bar0)-oriented 4H sample, luminescence features decrease when the excitation intensity increases, probably due to a more significant indirect transition band. The CL spectra also vary for the same sample, due to the impurity and the microscopic defect density variations. Comparisons between two local spectra taken in two distinct areas of the (11 (2) over bar0)-oriented 4H sample, and with images obtained by x-ray topography in the same areas, allow us to establish that some structural defects are involved in luminescence centres. A deep centre involved in green luminescence (at 1.80 eV) is found to be associated with basal plane dislocations with the Burgers vector b = (1/3)(11 (2) over bar0). PB Institute of Physics SN 0953-8984 YR 2004 FD 2004-01-21 LK https://hdl.handle.net/20.500.14352/51064 UL https://hdl.handle.net/20.500.14352/51064 LA eng NO © 2004 IOP Publishing Ltd.International Workshop on Beam Injection Assessment of Microstructures in Semiconductors (7. 2003. Lille,Francia). DS Docta Complutense RD 5 jul 2025