Evolution of ripple morphology on Si(100) by 60-keV argon ions

Anomalous behavior in temporal evolution of ripple wavelength under medium energy Ar+-ion bombardment on Si: A case of initial wavelength selection

“…It is known that the threshold fluences, flux, and the critical angle for pattern evolution on silicon surfaces are not unique at both low and intermediate energies. 4,9,13,22,40 For instance, the results in the present study differ from the previous studies 13,22,36 which were obtained under nearly similar experimental conditions. Likewise, in the present case, we get to see ripple patterns on crystalline Si surface at the fluence 1 Â 10 18 ions cm À2 , 22,36 while there are reports 41 at comparable energies, where ripple patterns are observed at even lower fluences on pre-amorphized Si surfaces.…”

“…4,9,13,22,40 For instance, the results in the present study differ from the previous studies 13,22,36 which were obtained under nearly similar experimental conditions. Likewise, in the present case, we get to see ripple patterns on crystalline Si surface at the fluence 1 Â 10 18 ions cm À2 , 22,36 while there are reports 41 at comparable energies, where ripple patterns are observed at even lower fluences on pre-amorphized Si surfaces. In another work, Chini et al observed that the wavelength and amplitude of Si ripples, evolved under comparable experimental conditions, can vary depending upon the beam scan rate.…”

“…4,9,12,36 However, ripple wavelengths at intermediate energies have much higher values (in the range of 700-1000 nm) compared to those formed at low energies. 36,37 Such higher values of the ripple wavelength at intermediate energies should remove the inherent limitation of addressing small changes in low-energy ion-induced ripple wavelength at lower fluences (as discussed above), albeit determination of ripple wavelengths at lower energies using advanced characterization tools has been demonstrated efficiently. 16 Therefore, for a better understanding of pattern formation at an early stage, intermediate energy keV ions can be an attractive tool.…”

Self-organized nanopatterning of silicon surfaces by ion beam sputtering

“…However, some early studies proposed that the threshold angle should be below 45 for 10-40 keV Xe þ ions [48,46], and below 55 for 30 keV Ar þ ions [84]. Very recently, Garg et al [85] have also reported that the threshold angle for 60 keV Ar þ ions is larger than 30 and lower than 45 . These trends contradict in some way those observed for low-energy ions, where Xe þ has a larger u c than Ar þ [64], being closer to 45 in the latter case [37,38,58].…”

Tunable wettability of Si through surface energy engineering by nanopatterning

“…From the literature, 60 angle of incidence is found to be a more favorable one for creating ripple patterns using 60 keV Ar + -ion energy. [26][27][28] A sessile drop method is used to measure the contact angle of water droplets on the ion sputtered surfaces. To explore the ion-beam induced structural and compositional modications, we have employed micro-Raman spectroscopy, cross-sectional transmission electron microscopy, and Rutherford backscattering spectrometry.…”