Third harmonic generation as a structural diagnostic of ion-implanted amorphous and crystalline silicon

Abstract

We demonstrate the use of third harmonic generation as a probe of the bulk symmetry properties of semiconductors. Using 20 ns, 1.06 μm laser pulses we have applied this probe to structural diagnostics of (100) annealed and unannealed Si wafers implanted with boron and arsenic ions at dosages above and below the threshold for amorphization. The presence of free carriers with densities up to 1021 cm−3 is found to increase the intensity but not alter the symmetry characteristics of the third harmonic light; the enhancement in the light level is attributed to a change in the reflectivity.