Local protrusions formed on Si(111) surface by surface melting and solidification under applied tensile stress

Self Cite

Si protrusions were fabricated by surface melting and resolidifying of a Si(111) wafer covered with a 100 nm thick molybdenum (Mo) layer, in which a narrow region was generated using a microgrinder. This region results in a narrow current path and thus localized resistive heating, leading to specific melting of the Si in the path. The melted Si flowed away from the path to both sides, which were at temperatures lower than that of the path. Consequently, two Si protrusions ∼400 μm in height capped with Mo silicide precipitates were formed on each side of the burned-out path, as revealed by scanning electron microscopy with energy-dispersive X-ray spectroscopy. The formation mechanism was discussed in terms of the non-uniform temperature, surface tension, interdiffusion, and freezing-point depression of the surface. This study revealed the potential of fabricating an array of self-assembled Si protrusions by resistive heating of narrow paths.

Section: Introductionmentioning

confidence: 99%

Fabrication of Si protrusions by local melting of a narrow current path on a Si wafer via resistive heating

Nishimura¹,

Tomitori²

2021

Self Cite

“…In addition, when the Si piece was heated at 1300 °C as in our previous report, 7) the left and right sides of the Si piece melted and two protrusions were produced. However, in this study, only one protrusion was produced on the left side of the Si pieces, which was heated at 1250 °C.…”

Section: Resultsmentioning

confidence: 63%

“…This is probably because the cap was crosssectioned via milling with a high-voltage 40 kV FIB beam, resulting in the amorphous-like structure, without irradiation of a low-voltage 2 kV FIB beam in order to avoid the Concerning the formation mechanism of the Si protrusion with its top cap, the temperature distribution plays an important role, as discussed in our previous report. 7) The Joule heat energy resistively generated in the Si piece dominantly dissipated at the two electrodes contacted with both ends of the Si piece and at the plunger contacted with the rear center of the Si piece, as denoted by arrows A-C in Fig. 3(a).…”

Section: Resultsmentioning

confidence: 99%

“…In addition, the two-dimensional arrays of nanoscale holes were used to arrange the positions of the nanoparticles between the holes; the interfacial free energy of the edge around the holes to the nanoparticles was different from that of the flat substrate. 5,6) We also reported that the Si protrusions were produced on the Si substrates, to which a tensile stress of ∼1 GPa was locally applied; 7) on the Si surface melted via DC current resistive heating, Si atom flows were induced owing to electromigration toward the regions at lower temperatures, where the migration slowed, and the melted Si solidified into the form of a protrusion. As the tensile stress reduced the resistive heat of the Si substrate owing to the piezoresistive effect of Si, the temperature was lower in the lower stressed region.…”

Section: Introductionmentioning

confidence: 94%

See 1 more Smart Citation

Microanalysis of silicon protrusions with a titanium cap formed via surface melting and solidification under applied tensile stress

Nishimura

Tomitori

2019

Self Cite

Silicon (Si) protrusions with a peculiar-shaped cap at their top were microanalyzed using scanning electron microscopy (SEM) with electron backscatter diffraction (EBSD) and scanning Auger electron spectroscopy/microscopy. The Si protrusions were formed on a Si(111) substrate via the process of surface melting by DC resistive heating above 1000 °C and solidification under applied tensile stress. The protrusions were micro-sampled by the techniques with focused ion beam, and their cross-sectioned planes were examined by SEM with EBSD. The analysis revealed that the Si protrusions were epitaxially grown as a single crystal on the Si(111) substrate and deposition of titanium (Ti) resulted in formation of the cap as Ti precipitation with other minor impurities. The formation mechanism of the Si protrusion was discussed in terms of surface melting flow in the non-uniform temperature distribution under stress via electromigration, diffusion suppression due to stress-induced steps, and solidification including freezing point depression of the melted Si with the impurities.

“…To date, Si protrusions have been formed by local melting of Si wafers and characterized. [14][15][16][17] Therefore, the surface of the Si wafer was locally melted by resistive heating of a Si narrow path while passing a current through it, leading to the flow of the melted Si from the path toward lower temperature regions. This melting process produced single-crystal Si protrusions by liquid-phase epitaxy upon cooling.…”

Section: Introductionmentioning

confidence: 99%

In situ observation of formation of Si protrusions by local melting of a Si narrow current path using resistive heating together with electron beam irradiation

Nishimura¹,

Tomitori²

2022

Self Cite

Silicon (Si) protrusions were grown by local surface melting and resolidified on a Si(111) fragment with a narrow current path that was fabricated using a microgrinder at the center of the fragment. The narrow path was resistively heated by passing a current through it until it burned. The surface of the narrow path and fragment gradually melted with increasing current, and the melted Si started to flow from the narrow path to its sides owing to the surface tension of the melted Si. When the fragment surface near the path was locally irradiated with an electron-beam, melted Si accumulated in the irradiation region, resulting in Si protrusions of ~600 µm in height. The formation mechanism of the Si protrusion was discussed based on in-situ optical microscope observations up to the burn-out of the Si narrow path.