Nanostructurale nature of the porous GaAs layer formed on p+-GaAs substrate by electrochemical anodization
A porous GaAs layer has been formed by electrochemical anodization in HF based solution on extremely doped p-type GaAs substrate. Porous nature of the elaborated sample has been evidenced by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Nanostructurale nature of the porous layer has been demonstrated by X-ray diffraction analysis (XRD) and confirmed by photoluminescence spectroscopy (PL).
Pores in III–V Semiconductors
The paper reviews electrochemically etched pores in III–V compound semiconductors (GaP, InP, GaAs) with emphasis on nucleation and formation mechanisms, pore geometries and morphologies, and to several instances of self‐organization. Self‐ organization issues include the formation of single‐crystalline two‐dimensional hexagonal arrays of pores with lattice constants as small as 100 nm found in InP, synchronized and unsynchronized diameter oscillations coupled to current and voltage oscillations, and pore domain formation. The findings are discussed in relation to pores observed in silicon. Some novel properties of the porous layers obtained in III–V compounds are briefly described.
Porous GaP multilayers formed by electrochemical etching
The properties of porous GaP, formed by anodic etching in H 2 SO 4 , are described. Pore size, pore density, and the interpore distance depend on the dopant density and the potential at which the sample is etched. In addition, it is shown that at high potential, the GaP passivates as a result of the formation of an oxide layer. These features allow us to grow multilayer structures of GaP with modulated porosity and/or oxide layers. The dissolution of oxide at the base of a porous layer can be used to produce freestanding porous membranes.