Lombardi's mobility model accounts for the effect of the transverse
electric on mobility in a MOSFET device. Lombardi's formulation adds
terms for surface acoustic phonon ( 
) and surface roughness
scattering ( 
) to the bulk mobility ( 
) using a
Matthiesen-like rule:
The bulk mobility ( ) can be from a variety of formulations,
typically the Arora model in Prophet. Lombardi gives the following
forms for and :
Table 3 summarizes the Prophet parameter names and
default values for the Lombardi mobility model.
Conventional usage expresses mobility in units of 
;
however, Prophet uses units of 
, so the numerical
values of the mobility parameters appear to be 
larger than
usual.
Table 3: Lombardi Mobility Model Parameters and
Default Values