Aligned, coexisting liquid and solid regions in laser-annealed Si

Aligned liquid and solid stripes are observed under continuous-wave laser illumination of Si films. For normally incident light, the stripes have a periodicity equal to the laser wavelength and are aligned perpendicular to the laser polarization. The dependence of the stripe spacing versus incident angle is also probed. Examination of the surface after cooling shows the presence of surface ripples with the same wavelength. Thus it is proposed that the liquid and solid Si stripes are the precursors of the ripples. It is suggested that aligned liquid-solid regions are obtainable for certain conditions for pulsed laser annealing of silicon.