Ultra thin films of atomic force microscopy grown SiO2 as gate oxide on MOS structures: conduction and breakdown behavior

Electrical conduction modes and breakdown of atomic force microscopy (AFM) grown SiO2 as gate oxide in metal–oxide–semiconductor (MOS) structures are studied, and the results are compared to those obtained from MOS capacitors with thermally grown SiO2. Gate current vs. gate voltage characteristics were obtained from standard electrical characterization techniques, i.e. wafer prober plus semiconductor parameter analyzer. To obtain suitable samples, AFM oxidation has been integrated in a CMOS microelectronic process. This characterization showed larger current levels and lower breakdown voltages for AFM grown gate oxides than for thermally grown gate oxides. On the other hand, I–V curves collected at a nanometric range by means of a conductive-AFM show a closer behavior for both kinds of oxides.