Macromodel View of a MOSFET: Definition of Parameters
Leff modeling
- Bias-independent, conceptual metallurgical channel length.
- Defined with the “Icrit@Vt0” definition.
- Extracted together with Vt.
Device/terminal inputs
Ldrawn - drawn gate length
Vgs, Vds, Vbs - terminal biases
Physical (average) parameters
tox - gate oxide thickness
xj - LDD junction depth
S - LDD spacer thickness
DCD - CD correction
Nss - oxide charge density
Physical (derived) parameters
Lg = Ldrawn - DCD
Lmet = Lg - 2sxj
Leff = Lmet = Ldrawn - DCD - 2sxj
Process (fitting) parameters
s - lateral LDD diffusion
fm - gate workfunction