Effect of annealing on focused ion beam induced surface damages in silicon analyzed by micro-Raman spectroscopy

In this paper, we describe Raman spectroscopic study for evaluating the influence of vacuum annealing on the surface modification of the focused ion beam (FIB) induced damaged layer on a single crystalline Si (c-Si) substrate. The damaged layer consisting of amorphous silicon (a-Si) with implanted Ga ions is formed after irradiating FIB onto the c-Si surface. After vacuum annealing at 700 degrees C for 10 s, the Raman spectrum peak of poly crystalline Si (p-Si) appears. With increasing annealing time, the spectral parameters, peak shift, peak intensity, and full width at half maximum (FWHM), for p-Si and c-Si change. Through the comparison between the phase fraction of a-Si, p-Si, and c-Si in the FIB damaged layer and the mechanical properties of the FIB-processed Si nanowires obtained in the quasistatic tensile testing, a recovery of the damaged layer by annealing is discussed.