Ultrafast laser surface irradiation of silicon: Effects of repetition rate in vacuum and air

Liquid‐Assisted Laser Nanotexturing of Silicon: Onset of Hydrodynamic Processes Regulated by Laser‐Induced Periodic Surface Structures

“…In fact, most of the studies on fs‐laser processing of Si was carried out under ambient environment revealing ability to create supra‐wavelength spiky morphologies (sometimes referred to as grooves) under accumulated exposure. These structure manifested themselves as a universal phenomenon being observed under diverse experimental conditions (such as visible and IR laser wavelengths, [ 35 ] angled excitation, [ 36 ] shaped beams, [ 54 ] GHz bursts, [ 38 ] vacuum conditions, [ 37 ] etc.) with their supra‐wavelength periodicity generally scaling with the incident wavelength.…”

“…[15][16][17] Monocrystalline Si (c-Si), a critically important semiconductor widely applied in variety of optoelectronic and nanophotonic devices, [18,19] was widely studied in the context of LIPSSs formation revealing the ability to produce on its surface both high spatial frequency LIPSSs [20][21][22][23][24][25][26][27][28][29][30] as well as quasi-regular suprawavelength patterns. [31][32][33][34][35][36][37][38] The latter type of the structures was generally explained by hydrodynamic processes, [39] yet their ordering along polarization direction and evident correlation between the characteristic periodicity and laser wavelength were established [34] reflecting the lack of complete understanding of the underlying physical processes driven morphology selforganization. In this respect, more systematic studies targeted at unveiling the role of hydrodynamic and electromagnetic processes in formation of supra-wavelength structures are required to achieve full-scale control over the surface morphology crucial for obtaining desired optical properties, as well as device performance optimization.…”

In-situ scanning tunneling microscopy of ultrafast laser damage on Si (100) surface in ultra-high vacuum

“…Prior work has shown that the native oxide on silicon can impact the ultrafast laser surface modification process. [5][6][7][8] For example, McDonald et al reported that oxidation increases the laser damage threshold of silicon, resulting in three distinct damage scenarios when considering the relationship between the thresholds for oxide and pure silicon. 5 The native oxide on Si is self-limiting to around 2nm in thickness after a couple of hours, 9 but can be readily removed using an HF acid etching process.…”

“…This enables comparative studies of in vacuo laser modification to identify the role of the native oxide. 5,7,10,11 Here, we report on the development of a system that allows for both laser damage and characterization in ultrahigh vacuum (UHV) (P < 10 −8 Torr). In particular, in situ characterization allows for atomic-scale imaging and spectroscopy by tools such as scanning tunneling microscopy (STM).…”

Heat accumulation effects in femtosecond laser-induced subwavelength periodic surface structures on silicon

“…Femtosecond laser-induced periodic surface structures (fs-LIPSSs) on various materials, such as metals, semiconductors [1][2][3][4][5][6] , and dielectrics [7] , have gained considerable attention and hold many potential applications in enhancing tungsten filament luminous efficiency [8] , enhancement of optical absorption and photocurrents [9] , metal colorization [10,11] , terahertz-emitting enhancement [12] , modulation of tribological property [13,14] , and superhydrophobic modification [15] . The mechanism responsible for fs-LIPSSs is still a matter of debate.…”