257
Process Compact Modelling of Strain-Engineered MOSFETs
sensitivities, the variation of I on becomes larger during technology scaling,
even if the normalised process variation remains constant, e.g., –20% and
–12% for L eff and N ch variations, respectively (Figure 9.9). For future technology generations, L eff will continue to be the dominant factor affecting performance variation, because of its role in velocity overshoot and the DIBL effect.
5
4
3
2
1
0
10
100
CV/l (ps)
CV
dd
2
(fJ)
4
3
2
1
0
L eff (nm)
32 nm
45 nm
65 nm
90 nm
130 nm
180 nm
250 nm
FIGURE 9.8
Prediction of nominal CV/I and CV dd
2 from 250 nm to 32 nm nodes. (After Zhao, W., Predictive
Technology Modelling for Scaled CMOS, PhD thesis, Arizona State University, 2009.)
70%
60%
50%
40%
30%
20%
10%
0%
10
100
L eff (nm)
65 nm
45 nm
32 nm
90 nm
130 nm 180 nm
250 nm
L eff only
DIBL
Velocity overshoot
–20% L eff variation
–12% N ch variation
FIGURE 9.9
The impact of L eff variation on I on across technology generations. (After Zhao, W., Predictive
Technology Modelling for Scaled CMOS, PhD thesis, Arizona State University, 2009.)