Fractal model of a porous semiconductor

✍ Scribed by V.M Aroutiounian; M.Zh Ghoolinian; H Tributsch

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 174 KB
• Volume: 162-163
• Category: Article
• ISSN: 0169-4332
• DOI: 10.1016/s0169-4332(00)00180-x

✦ Synopsis

In the present paper, it is shown that a porous silicon can be presented as a set of clusters of silicon atoms surrounded by SiO , whereas the single crystalline silicon substrate can be considered as an infinite cluster. The formulae for the estimation x Ž of variable porosity of the material including the value of critical porosity -the percolation threshold, after which the . characteristic phenomena are expected in porous silicon and the forbidden bandgap value of clusters are suggested as functions of sizes of nanocrystallites.

A new fractal model of the pore creation on the surface of a material is also proposed. The cases of semi-spherical, Ž . Ž . conical V-groove dielectric isolation technology and cylindrical U-groove dielectric isolation technology are considered. Formulae for the formed surface area S, porosity p of the material as a function of the depth and fractal dimension are obtained.