Surface recombination velocity in Si wafers by photoinduced thermal emission

摘要

A contactless, all-optical, nondestructive approach is presented for the steady-state measuring of the surface recombination velocity in Si wafers at a low injection level and well above room temperature. The fundamentals and technique of this approach are based on the analysis of the below-band-gap (3-5 μm) nonequilibrium thermal emission versus the wavelength of the above-band-gap light pump ( < 1 μm) that generates excess free carriers. Experimental results for Si wafers (400 K< T < 600 K) which were submitted to different surface treatments are reported. Limitations to this technique are also discussed.