Oxidation of macroporous silicon for thick thermal insulation

Silicon Porosification: State of the Art

“…However, we have to note that in reality the number of components which could be included in the electrolyte for Si etching is much more than 3. For example, in several articles [381][382][383] it was proposed to use as an electrolyte hydrofluoric acid (HF) diluted with Dimethyl Sulphoxide (DMSO). The solvent DMSO was chosen because it yields a faster etch rate than the others, such as H 2 O, ethanol, or Dimethylformamide (DMF).…”

“…DMSO can also produce pores with a larger range of current density and form smaller pores in random (no mask patterning) samples. 381,383 Replacing C 2 H 5 OH by other alcohols has been the subject of a systematic study, aiming to decrease the roughness of pore walls in the case of n-macropores. 384 Making the electrolyte more viscous by adding glycol or glycerol has emerged more recently as a means to make not only better macropores (e.g., with smoother walls) but also mesopores.…”

“…110,[476][477][478] Many oxidation methods exist, such as aging in ambient, 479 exposure to water vapor, [480][481][482] anodic oxidation in a non-fluoride electrolyte, 142,179,[483][484][485] 479 and thermal oxidation in wet and dry O 2 fluxes, 189,381,[488][489][490][491] including rapid thermal oxidation. 477 A data review regarding a wide range of oxidation treatments (e.g., thermal treatments, electrochemical and chemical oxidation, pthotochemical oxidation, etc.)…”

Fabrication of DNA purification microchip integrated with mesoporous matrix based on MEMS technology

“…To improve the surface properties, the porous silicon required thermal oxidization for forming amounts of silanol groups which can interact with DNA. From the previous researches (Kan and Finstad 2005), porosity of 55% was the critical porosity for achieving complete oxidation. Furthermore the pore structure with a higher porosity would be too fragile for making a practical SiO 2 layer.…”

Porous silicon for electrical isolation in radio frequency devices: A review

“…48 From this point of view, macroporous silicon has also shown some interesting capabilities to produce high thickness silicon oxide isolation layers. 49 …”