Ultraviolet (UV) raman characterization of ultra- shallow ion implanted silicon

Ion implant damage to the Si lattice was investigated using ultraviolet (UV) Raman spectroscopy under two UV excitation wavelengths (266.0 and 363.8 nm) with probing depths of ~2 and ~5nm into the surface. Ultra-shallow implantation of B⁺ and BF₂⁺ ions with and without Ge pre-amorphization implantation (PAI) into 300mm diameter n-type Si(100) wafers were prepared. Raman peak broadening and shape change, corresponding to the degree and depth of ion implantation damage to the Si lattice, were measured. Changes of reflectance spectra in the UV and visible wavelength region caused by the ultra-shallow ion implantation were measured and correlated with Si lattice damage evaluated by UV Raman spectroscopy, secondary ion mass spectroscopy (SIMS) and high resolution transmission electron microscopy (HRXTEM). UV Raman spectroscopy is a very promising non-contact Si lattice damage characterization technique for ultra-shallow ion implanted Si and can be used as an in-line damage and electrical activation monitoring technique.