The effect of both temperature and electrolyte concentration on the
formation of porous layers in InP is explored. Pore width, porous
layer thickness and porosity decrease with increasing temperature
and show a minimum at intermediate KOH concentrations,
increasing as concentration is either increased or decreased from
that value. The variations in pore width and layer thickness are
correlated: thinner pores appear to limit layer thickness,
presumably by influencing mass transport throughout the porous
network. A three step model of charge transfer at the
semiconductor/electrolyte interface is used to explain these
observations.