Investigations on the Si/SiO2 interface defects of silicon nanowires

Silicon nanowires have been fabricated by the metal-assisted chemical etching method. The etching rate of silicon can be adjusted by changing the concentration of titanium in the solution. Investigations by electron spin resonance of silicon nanowires show that Pb0 center is the prominent defect at the Si/SiO2 interfaces, and its density decreases as the etching rate decreases. The red-shift of the Raman peak with decrease of the etching rate indicates a progressive increase of tensile strain in Si at the interface, which induces the shortening of the length of the Si-O bond confirmed by the Fourier transform infrared spectrometer investigations.