2.3.2 Modeling Concept

For all models in MINIMOS-NT the general approach is to employ universal models, i.e. the same functional form to be used for all materials, just with different parameter sets. In models for alloy materials the respective models for the two basic materials are employed first and then combined as a function of the material composition $x$. Additionally, full consistency between the alloy materials and the basic materials is obtained by having all the models for alloy materials inheriting their model parameters from the models for basic materials. Although it is arbitrary which of the two basic materials will correspond to a mole fraction $x=0$ and which to a mole fraction $x=1$, a choice has to be done, e.g. InGaAs is used for In$_x$Ga$_{1-x}$As and not for In$_{1-x}$Ga$_x$As. The alloy materials (A$_{1-x}$B$_x$) formed by the basic materials (A and B) are summarized in Table 2.5.

Table 2.5: Mole fraction $x$ in alloy materials

	A	B	A$_{1-x}$B$_x$
SiGe	Si	Ge	Si$_{1-x}$Ge$_x$
AlGaAs	GaAs	AlAs	Al$_x$Ga$_{1-x}$As
InGaAs	GaAs	InAs	In$_x$Ga$_{1-x}$As
InAlAs	AlAs	InAs	In$_x$Al$_{1-x}$As
InAsP	InP	InAs	InAs$_x$P$_{1-x}$
GaAsP	GaAs	GaP	GaAs$_{1-x}$P$_x$
InGaP	InP	GaP	Ga$_x$In$_{1-x}$P