Nanoscale structural defects in oblique Ar+ sputtered Si(111) surfaces

Abstract

The present endeavor investigates the controlled surface modifications and evolution of self-assembled nano-dimensional defects on oblique Ar+ sputtered Si(111) surfaces which are important substrates for surface reconstruction. The defect formation started at off-normal incidences of 50° and then deflates into defined defect zones with decrease in oblique incidence, depending strongly on angle of ion incidence. Interestingly, it is observed that mean size & height decreases while average density of these defects increases with decreasing oblique incidence. Non-linear response of roughness of irradiated Si(111) with respect to oblique incidence is observed. Crystalline (c-Si) to amorphous (a-Si) phase transition under oblique argon ion irradiation has been revealed by Raman spectroscopy. Our analysis, thus, shows that high dose argon ion irradiation generates of self-assembled nano-scale defects and surface vacancies & their possible clustering into extended defect zones. Explicitly, ion beam-stimulated mass transport inside the amorphous layers governs the observed defect evolution. This investigation of crystalline (c-Si) coupled with amorphous (a-Si) phases of nano-structured surfaces provides insight into the potential applications in the nano-electronic and optoelectronic devices thus, initiating a new era for fabricating multitude of novel structures.

The impact of fluence dependent 120 MeV Ag swift heavy ion irradiation on the changes in structural, electronic, and optical properties of AgInSe2 nano-crystalline thin films for optoelectronic applications

“…41,42 At low ion uences, where tracks do not overlap, these corrugations would be more due to random protrusion of materials from the track region 43 or even due to materials sputtered out of the point of impact of the ions on the surface. 44,45 As a consequence, the amplitude of the oscillation is reduced at the uence of 1 Â 10 12 ions cm À2 , where the surface will be highly roughened due to incomplete overlap of ion tracks, leading to the reduced amplitude of oscillations as observed (Fig. 5a).…”

Ripple pattern formation on silicon carbide surfaces by low-energy ion-beam erosion

“…SiC. Thus, for all argon ion fluence, sputtered SiC surfaces will be rich in carbon because of preferential erosion of Si atoms from the surface region [2,[10][11].…”

Nano-scale depth-varying recrystallization of oblique Ar+ sputtered Si(111) layers

“…6b,d,f), the spectra consists of a broad amorphous band (a-Si), being centered at (450 ± 3) cm −1 . This band is ascribed to the amorphous silicon (a-Si) having transverse optic TO mode [35][36][37][38][39] . The appearance of a-Si peak (Fig.…”

“…Besides recovery by annealing treatment, some stress still remains in the recrystallized Si(111) samples. This remnant stress has been signified by shifting of the Raman peak in these recrystallized specimens towards the lower wave numbers in comparison to un-irradiated c-Si, which is stress free 18,[35][36][37][38][39] . The magnitude of this stress has been estimated 39 using the relation:…”