Macropore formation in p-type silicon: toward the modeling of morphology.
The formation of macropores in silicon during electrochemical etching processes has attracted much interest. Experimental evidences indicate that charge transport in silicon and in the electrolyte should realistically be taken into account in order to be able to describe the macropore morphology. However, up to now, none of the existing models has the requested degree of sophistication to reach such a goal. Therefore, we have undertaken the development of a mathematical model (phase-field model) to describe the motion and shape of the silicon/electrolyte interface during anodic dissolution. It is formulated in terms of the fundamental expression for the electrochemical potential and contains terms which describe the process of silicon dissolution during electrochemical attack in a hydrofluoric acid (HF) solution. It should allow us to explore the influence of the physical parameters on the etching process and to obtain the spatial profiles across the interface of various quantities of interest, such as the hole concentration, the current density, or the electrostatic potential. As a first step, we find that this model correctly describes the space charge region formed at the silicon side of the interface.
Unité de recherche matériaux procédés et environnement (UR-MPE), Faculté des sciences de l'ingénieur, Université M'Hamed Bougara, Cité Frantz Fanon, 35000 Boumerdès, Algeria ; Département de physique, Faculté des sciences, Université M'Hamed Bougara, 1, Avenue de l'indépendance, 35000 Boumerdès, Algeria.
Amel
A
Slimani
Unité de recherche matériaux procédés et environnement (UR-MPE), Faculté des sciences de l'ingénieur, Université M'Hamed Bougara, Cité Frantz Fanon, 35000 Boumerdès, Algeria.
Aicha
A
Iratni
Physique de la Matière Condensée, École Polytechnique, CNRS, 91128 Palaiseau, France.
Hervé
H
Henry
Physique de la Matière Condensée, École Polytechnique, CNRS, 91128 Palaiseau, France.
Mathis
M
Plapp
Physique de la Matière Condensée, École Polytechnique, CNRS, 91128 Palaiseau, France.
Jean-Noël
JN
Chazalviel
Physique de la Matière Condensée, École Polytechnique, CNRS, 91128 Palaiseau, France.
François
F
Ozanam
CRTSE, 2 Bd Frantz Fanon, BP 140, Alger-7 Merveilles 16200, Algeria.
Noureddine
N
Gabouze
Anisotropic etching; Macropore morphology; Phase-field model; Porous silicon