Silicon surface

The silicon—silicon-dioxide system is of utmost importance to all silicon devices both unipolar and bipolar. A metal-oxide—silicon diode presents an excellent tool for the study and understanding of the behaviour of the silicon surface under various conditions. With the help of the capacitance—voltage characteristic of such a diode it was possible to shed light on the nature of the depletion, accumulation, and inversion layers at the silicon surface. Extensive studies of the Si-SiO2 system using C-V plot and, of course, other techniques revealed the nature of the various existing surface states and charges. The presence of the interface states and mobile and fixed charges modify profoundly the electrical properties of the silicon surface affecting seriously such bipolar device parameters as electric breakdown or leakage currents.