Controllable Fabrication and Mechanism of Macropores Formation on p-Type Silicon

Macropores were prepared by electrochemical etching on p -type silicon. The effects of resistivity, etching time and HF concentration on the porosities and morphologies of macropores were investigated. It was found that the porosity of p -type macropores increased exponentially at the beginning with the increase of etching time under any other etching parameters. In addition, we discovered that HF concentration had significant effect on the surface and cross-section morphologies of macropores. The dependence of the macropore formation mechanism was discussed, and the hydrogen escape mechanism as well as current-burst-model (CBM) was employed to interpret the underlying mechanism and the morphology control during macropore formation.