Photoacoustic spectroscopy: investigation of sputter damage in Si surface by Ar plasma

Abstract

The effect of Ar plasma etching on the surface of Si was investigated by photoacoustic spectroscopy. The surface of Si sample (p-tip, 10 k/spl Omega/cm, 420 /spl mu/m) was treated with Ar plasma from 2 min to 80 min. Amplitude and phase PA spectra were measured in the energy range from 0.75 to 1.55 eV. The amplitude ratio and phase difference of photoacoustic signals of Si samples Ar plasma etched and incoming Si samples indicate existence of two surface energy states (the generation-recombination centers) at 0.31 and 0.99 eV.