Effect Of Nitrogen Passivation On The Performance Of Mim Capacitors With A Crystalline-Tio2/Sio2 Stacked Insulator

TiO2/SiO2 stacked dielectric-based metal-insulator-metal capacitors with different thermal and nitrogen plasma treatments (NPTs) were explored in this letter. As the TiO2 dielectric crystallizes from amorphous phase after a thermal treatment, capacitance density increasing from 7.7 to 11.9 fF/mu m(2) was obtained at the price of aggravating leakage current and wider distribution in device characteristics. With NPT to well passivate grain-boundary-related defects in the crystalline TiO2 film, devices still keep a satisfactory capacitance level of 11.2 fF/mu m(2) while exhibiting suppressed leakage current by a factor of 53, a lower quadratic voltage coefficient of capacitance (VCC-alpha) of 30 ppm/V-2, near frequency dispersion-free capacitance, a better temperature coefficient of capacitance of 82 ppm/degrees C, and more controllable device uniformity. The mechanism for the improved electrical characteristics was further confirmed by atomic force microscope. These results suggest that NPT paves a new avenue to further advance the performance of crystalline dielectric-based devices.