Luminescence from color centres induced by oxidation and ion irradiation in 4H–SiC.

We report on the generation of radiative defects, the so-called color centres, in 25 keV He irradiated and thermally oxidized 4H–SiC < 0001 > surface investigated by photoluminescence spectroscopy utilizing 266 nm deep-UV excitation. Ion irradiation showed the generation of photoluminescent peaks ascribed to silicon vacancies (V Si) and unknown defect-related bands (UD 3 and UD 4). Thermal treatment (200–800 C) resulted in a significant increase of luminescence at an optimal temperature, depending on the initial density of emitters. While thermal oxidation resulted in several other high-brightness color centres, emitting photons even at room temperature. In addition to the defects in the crystalline 4H–SiC lattice, the difference in photoluminescence after oxidation indicates the presence of various other complex surface and interfacial defects. [Display omitted] • Generation of radiative defects: • Generation of silicon vacancies (V Si) and unknown defect-related bands (UD 3 and UD 4) in 4H–SiC after ion irradiation. • Thermal oxidation induced high-brightness room-temperature color centres. (including surface emitters from the oxide layer and oxide-bulk interface) • Role of ion fluence (He/cm2) on the emission intensities from the color centres. • Isochronal thermal annealing (200–800C) study of the color centres generated in ion irradiated 4H–SiC. • Temperature-dependent photoluminescence (77–300K): The effect of temperature in luminescence from the oxidation-induced color centres. [ABSTRACT FROM AUTHOR]