Detection of Border Trap Density and Energy Distribution Along the Gate Dielectric Bulk of High-$\kappa$ Gated MOS Devices

A novel charge-pumping (CP) technique is demonstrated to extract border-trap distribution for high- kappa gated MOSFETs. The varying-frequency CP method is shown to be more effective than the varying-amplitude one for probing border traps and extending the tunneling depth. A linear relationship of the Q
_cp
versus ln(T
_r
T
_f
)
^1/2
plot can only be maintained at the CP frequency of 1 MHz, while not below 1 MHz, due to the influence of border traps near HfO
_x
N
_y
/Si interface. The proposed technique, which takes into consideration the effect of carrier tunneling in slow oxide traps, is used successfully to obtain the spatial and energy dependence of bulk trap density in high-kappa bulk