Ultrarapid anodic dissolution of silicon in HF-free solutions is reported. Although the etch rates are insignificant up to a potential of 25 V, when shifting the potential to higher values of 35-55 V the silicon etch rate reached a record value of more than 30 mu m/min. In addition, surface morphologies are notably affected by the applied potential, modifying the surface from a porous one to a partially polished one. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3358141] All rights reserved.