Electrochemical structuring of mechanically activated n‐InP(100) surfaces

Abstract

Localized pore formation on n-InP(100) surfaces under anodic polarization in 1M HCl were created and controlled by a two steps approach. First, scratches in the nanometer scale have been applied mechanically, using a Nano-Indenter. These scratches represent activated sites for pore growth due to their lowered electrochemical pore formation potential (U bd,activated ), which is significantly cathodic to the formation potential on intact surfaces U bd (U bd,intact ). Thus, a potential window can be defined between U bd,activated and U bd,intact , where anodic polarization in 1M HCl leads to selective pore formation follows, at a potential that is inside those window. Characterization by scanning electron microscopy shows that pore formation occurs only at the activated sites. Furthermore, both broadening and morphology of the pores depend strongly on the force load during the scratching process. Analysis of the scratched surface has been carried out before and after etching, using atomic force microscopy (AFM). The results clearly show that the porous region is significantly wider than the originally scratched region -this can be ascribed to dislocation formation in the vicinity of the scratch.