Current interruption was used to measure silicon dioxide layer capacitance and Si oxidation activation energy at 20∼70°C.
A current interrupter was built using an electromagnetic relay and integrated circuits. When Si was anodized in an ethylene glycol solution, the current between the n-type Si wafer anode and Pt cathode was interrupted for 5ms on galvanostatic electrolysis, and the transient phenomena of voltage waveform, form which short term anodic oxidation kinetic parameters are obtained, were observed by a digital memory scope.
Oxide film capacitance increased rapidly beyond a current density of 1mA cm^-2. Oxide film capacitance increased with electrolyte temperature up to about 40°C, but decreased as temperature increased from 45°C to 50°C. Activation energy for silicon anodic oxidation was about 23.7kJ mol^-1 over 55°C and 122kJ mol^-1 at 20∼40°C.