Transistor Mismatch Properties in Deep-Submicrometer CMOS Technologies

Transistor mismatch data and analysis from poly/SiON and high-k/metal-gate (HKMG) bulk CMOS technologies are presented. It is found that the traditional mismatch figure of merit from the Pelgrom plot (A
_VT
) continuously scales down as technology advances. Furthermore, the A
_VT
values for both nFET and pFET in the HKMG technology are significantly reduced from poly/SiON technologies. By normalizing the mismatch data against electrical oxide thickness (T
_INV
) , threshold voltage (V
_TH
), and effective work function, a direct comparison of the mismatch data from various technologies is made. The differences in nFET and pFET mismatch behaviors in both poly/SiON and HKMG technologies are discussed in detail. Correlation between transistor V
_TH
mismatch and flicker noise variation is observed in both poly/SiON and HKMG technologies. Finally, it is quantitatively demonstrated that effective work function variation does not generate significant V
_TH
variability in the present HKMG technology.