The effect of different chemical treatments on the surface morphology of p-type Si(001) surfaces was studied by atomic force microscopy and scanning tunneling microscopy. The electrical parameters of Al/Si Schottky diodes fabricated on the etched surfaces were correlated with the morphological characteristics. The surface of NH4F-treated surfaces shows pore formation and anisotropic etching. Hydrogen bubbles formed on this surface act as microscopic masks during the NH4F etching, leading to preferential etching at mask borders. Smoother, passivated areas which are not attacked are observed on the surface. The etching proceeds sometimes beneath these passivated areas, eventually yielding suspended structures. A correlation between surface roughness and electrical "leakage spots'' is observed in the fabricated diodes. (C) 2004 The Electrochemical Society.