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 (AVT) continuously scales down as technology advances. Furthermore, the AVTvalues 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 (TINV) , threshold voltage (VTH), 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 VTHmismatch 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 VTHvariability in the present HKMG technology.