New insights into Si electrochemistry and pore growth by transient measurements and impedance spectroscopy

Silicon electrochemistry has many applications, but still a number of unans wered questions. This paper reports on experimental results of current tran sient measurements and impedance spectroscopy along the I-U curve in the Si -HF system. The points of inflection of the I-U characteristics are found t o be interesting, signaling the onset of new mechanisms supporting or suppr essing current now which are mostly coupled to oxide formation and/or disso lution. The results are interpreted in terms of interactions of current hur sts in time and in space. Following this interpretation, in-situ monitoring of pore nucleation and growth with FFT impedance spectroscopy, allowed to identify several phases of macropore formation and optimal growth condition s. In-situ monitoring of macropore growth may therefore be used to control nucleation and growth of macropores.