Selective-area room temperature visible photoluminescence from SiC/Si heterostructures

SiC/Si heterostructures have been patterned by reactive ion etching with CHF3/O2 to produce SiC-covered and Si-exposed regions with lateral dimensions of 2.5 to ∼500 μm. The patterned samples were then anodized in HF/ethanol solutions. Short anodization times (<3 min) result in selective-area UV-induced visible photoluminescence (PL), with a peak located at 650 nm, being observed at 25 °C from only the SiC-covered regions. The emission is generated by porous Si (PoSi) selectively formed under the SiC cap and transmitted through the wide band-gap SiC layer. Longer etching times result in nonselective PL.