Download - Curve Fitting results 1110
Curve Fitting Results
Ray
Log(Id)
VGS
Sqrt(Id)
VGS
Weak-Inversion Fitting
Chip #1
Chip #2
Weak-Inversion Fitting Temperature Effect
Chip #1
T = 65F
T = 80F
T = 90F
Sqrt(Id)
VGS
Curve Fittings from Square Root of Drain Current
Threshold voltage
Slope1
Slope2
slope drops due to the degradation of mobility
Depletion region charge
Threshold Voltage Fitting results
Chip #1T = 65FT = 80FT = 90F
Chip #2
T = 69F
Leakage when Vgs = 0V
VDS
Punch-through
GIDL
DIBL
Mobility Ratio Fitting results
Chip #1T = 65FT = 80FT = 90F
Chip #2
T = 69F
Slope1 Slope2 K3
For chip#1, mobility will drop fourfold while it drops 2.5 times for chip #2
Velocity Saturation
Chip #1
T = 65F
T = 80F
T = 90FChip #2T = 69F
further to velocity saturation
closer to velocity saturation
Mobility ratio Fitting Velocity Saturation Dominant Case
Chip #1
Chip #2Mobility only drops 1.1 times!
Mobility only drops 1.04 times!
Problems So Far
• In mobility ratio fitting results, the difference in two slopes lying only in the assumption of mobility difference under standard square law equation.
• However, as the previous slide show, if velocity saturation kicks in, square law doesn't hold and the index can also be an coefficient. Thus, the mobility degradation effect will be reduced.
• Nevertheless, the temperature effect is not affected.
We need to understand the physics here to choose which phenomenon is here presented.