Droplet formation during laser sputtering of silicon

UV N2 laser ablation of a Cu–Sn–Zn–Pb alloy: Microstructure and topography studied by focused ion beam

“…The non-uniform energy distribution of the laser beam caused several topographic changes on the irradiated surface. Similar effects were also observed during irradiation of other metals by the same laser [12]. Three zones could be defined after inspection of the irradiated surface:…”

“…Firstly, there were many redeposited products on the surface measuring around 50 nm, which is typical for particles caused by phase explosion. Secondly, in previous work [12] it was calculated that the temperature of silicon can attain 20,000 K when irradiated by an energy density of 1.1 J/cm 2 ; the observed plasma temperature was then 16,000 K. In our case the measured plasma electron temperature was ≈14,000 K. This is much higher than the copper boiling temperature (2833 K, [13]). According to this, it can be concluded Table 1 Melting point, boiling point, heat of fusion and heat of evaporation of chemical elements in the investigated Cu-Sn-Zn-Pb alloy [13] Melting point ( • C)…”

“…The total irradiated target surface was 75 mm 2 , however only the central part with the maximal energy density produced melting and crater on the target. The laser beam had very non-uniform energy distribution, which is typical for this type of laser [12]. Fig.…”

Target-plane deposition of diamond-like carbon in pulsed laser ablation of graphite

“…The tight ''plastering'' of individual nanograins may suggest that there is a possibility that the laser-ablated debris could be liquid droplets [20][21][22], as a result of subsurface melting for the laser ablation of graphite, silicon, and germanium. These may also be understood by the pulsed laser-induced phase explosion, which creates the super-critical heating and melting of the subsurface materials [23], although the subsurface boiling was disputed [24].…”

Induced hydrophobicity in micro‐ and nanostructured nickel thin films obtained by ultraviolet pulsed laser treatment

“…Surface features such as droplets and the use of a moderate fluence < 7 J/cm2 [37] point towards pressure-induced melt displacement being the main mechanism behind the generation of the surface morphology, with some melt instability that results in droplet ejection and recondensation on the surface [43]. In this context, 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 the observed craters could be the consequence of bubble entrapment during melt pool solidification [44][45][46], or bubble formation at the interface between redeposited ejected droplets and the solid substrate [47].…”