THE POTENTIAL DISTRIBUTION AT THE SILICON ELECTROLYTE INTERFACE IN HF SOLUTIONS

The potential distribution at the silicon/electrolyte interface was studied in HF solutions using capacitance measurements in conjunction with impedance measurements over a wide frequency range. The electrode impedance was sensitive to the reactions occurring during anodic polarization. The n silicon exhibited a characteristic response of a deep depletion layer up to potentials of several volts. For p-silicon, the impedance was related to the potential drop across the space charge layer and the Helmholtz layer. At more positive potentials, the potential drop across the Helmholtz layer became dominant.