The Lombardi Surface Mobility Model (S) subnode is available from the context menu (right-click the Semiconductor Material Model parent node) or from the Physics toolbar, Attributes menu. It changes an input mobility to account for surface effects, particularly surface roughness and scattering due to acoustic phonons. The ‘S’ in brackets indicates that the model includes surface effects only. The mobility model accepts input mobilities of type L, LI, or C as well as user-defined input mobilities.

The set of equations defining the Lombardi Surface mobility model is shown in the Equation section.

These settings are the same as for Fletcher Mobility Model (C).

The Electron input mobility μn,in (SI unit: m2/(V⋅s)) parameter is used to define an input mobility. The default is User defined for silicon at equilibrium, 1448 cm2/(V⋅s).

The Hole input mobility μp,in (SI unit: m2/(V⋅s)) defines an input mobility. The default is User defined for silicon at equilibrium 473 cm2/(V⋅s).

The default for each of the following is taken From material. For User defined enter a different value or expression in the text field.

The default for each of the following is taken From material. For User defined enter a different value or expression in the text field.

To display this section, click the Show More Options button () and select Advanced Physics Options. Enter a Current density activation threshold Jtol (SI unit: A/m2). The default is 1·106 A/m2.