Structure and Surface Modification of Porous Silicon

Abstract

We need to recognize that morphology control and structure reproducibility present great problems with porous Si, especially mesoporous and nanoporous silicon applied in gas sensors. It was established that there are too many factors which in fl uence PSi morphology. PSi porosity and morphology depend on electrolyte composition, current density, lighting, magnetic fi eld, ultrasonic agitation and etching time during anodization, pH and temperature of solution used, orientation and doping of wafer, surface patterning, etc. (Korotcenkov and Cho 2010a ) . Several examples of the indicated factors that in fl uence PSi porosity and pore size are shown in Fig. 26