MORPHOLOGICAL STUDIES OF FOROUS SILIOCN FABRICATED BY GALVANOSTATIC ELECTROCHEMICAL ETCHING METHOD

With the orthogonal experiment, porous silicon (PS) was fabricated by galvanostatic electrochemical etching method. Surface morphology of PS was observed by Atomic Force Microscopy (AFM), and the effect of the electrochemical etching parameters on the surface morphology was studied systematically. The increased CHF concentration makes the critical current density (JPS) higher, which enhances the formation of PS. The current density is the main factor affecting the radius of the etched holes and the remaining silicon columns and the porosity. The higher current density makes the porosity and the radius of the etched holes and larger and the left silicon columns smaller. The anodization duration mainly affects the radius and thickness of the etched holes. The longer the anodization duration is, the thicker the PS layer and the larger of the radius of the etched holes will be.