Influence of Illumination on Porous Silicon Formed by Photo-Assisted Etching of p-Type Si with a Different Doping Level

Abstract

The influence of illumination intensity and p-type silicon doping level on the dissolution rate of Si and total current by photo-assisted etching was studied. The impact of etching duration, illumination intensity, and wafer doping level on the etching process was investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), and Ultraviolet-Visible Spectroscopy (UV-Vis-NIR). The silicon dissolution rate was found to be directly proportional to the illumination intensity and inversely proportional to the wafer resistivity. High light intensity during etching treatment led to increased total current on the Si surface. It was shown that porous silicon of different thicknesses, pore diameters, and porosities can be effectively fabricated by photo-assisted etching on a Si surface without external bias or metals.

Laser Photochemical Nanostructuring of Silicon for Surface Enhanced Raman Spectroscopy

“…The resulting nanoholes are shown in the SEM image in Figure 9a. The overall reaction occurs as follows [11,31] Si 2H O 6HF H SiF 4H O…”

“…The resulting nanoholes are shown in the SEM image in Figure a. The overall reaction occurs as follows [ 11,31 ] $$\[{\rm{Si}} + 2{{\rm{H}}_2}{{\rm{O}}_2} + 6{\rm{HF}} \to {{\rm{H}}_2}{\rm{Si}}{{\rm{F}}_6} + 4{{\rm{H}}_2}{\rm{O}}\]$$…”

“…Although basic scientific studies of photochemically nanostructured Si have used in several applications like sensing, anti-reflection coatings in photo voltaics, SERS substrates, and so on. [11] Crystalline Si surface can be structured in many ways; directly by pulsed laser, plasma, and wet etching. These periodic, [12,13] porous, [14][15][16] or black Si structures are also structured with synthesized plasmonic nanoparticles, [17] however; those substrates may suffer from the non-uniformity of the localized surface plasmon resonance (LSPR) along the surface.…”

Editorial for the Special Issue on 2D Nanomaterials Processing and Integration in Miniaturized Devices

“…Such a plethora of material/application combinations, in addition to the obvious technical requirements related to the synthesis of materials and the optimization of purity, composition, morphology and yield, also presents significant technological challenges for the corresponding processing, patterning and above all integration into systems and devices of higher dimensionality for the real exploitation of their unique properties. The present Special Issue is then focused on such last topics, collecting eight research papers and one review article dealing with MoS 2 [ 1 ], graphene [ 2 , 3 , 4 ] and other 2D nanomaterials integrated onto several kinds of materials and structures (nanogap [ 1 ], porous silicon [ 5 ], silicon carbide [ 6 ]) and for different applications (photoluminescence [ 1 ], ink-jet printing [ 7 ], optics and plasmonics [ 2 , 8 ], lubrication [ 3 ], innovative patterning [ 4 ], biomedicine [ 9 ]).…”

“…Volovlikova et al [ 5 ] analyzed the effect of illumination intensity and p-dopant concentration on the dissolution properties of silicon for its photo-assisted etching with no external bias or metals to produce porous silicon. A thorough characterization was performed, providing valuable data for the control of porous silicon thickness and porosity.…”