Photoacoustic evaluation of defects and thermal conductivity in the surface layer of ion implanted semiconductors

The photoacoustic (PA) method is a potentially suitable measurement technique for the evaluation of the local thermal conductivity in the vertical-depth direction of semiconductors. We measured the annealing behavior of the thermal conductivity and paramagnetic defects in the surface layer of ion implanted silicon by using the PA and electron spin resonance (ESR) methods. The thermal conductivity increases at annealing temperatures above 600 °C and reaches a value as high as 168 W m−1 K−1, which is the value of Si at 750 °C. The coefficient of correlation between thermal conductivity and ESR signal intensity was −0.98, i.e. the correlation was very good. The density of defects was evaluated through the annealing behavior of the thermal conductivity.