TABLE OF CONTENTS Modelling of advanced III V semiconductor devices appears to be a less rigorous approach than for silicon devices as the material properties for modelling of AlGaAs, InGaAs or even InAlAs, and InGaP are restricted to slight modifications of GaAs material properties. Also, the database for novel materials, such as GaN or GaSb, which have entered the III V material systems with impressive device results, is still relatively limited. Modelling of stress-induced changes of the physical properties of strained material layers and consideration of piezoelectric effects is a subject of ongoing research [36].
The two-dimensional device simulator MINIMOS-NT has been extended to deal with different complex materials and structures, such as binary and ternary semiconductor III-V alloys with arbitrary material composition profiles. It is well known that GaAs-HBTs with InGaP emitter material can be improved with respect to reliability if the emitter material covers the complete p-doped base layer forming outside the active emitter, the so-called InGaP ledge. Palankovski et al. [148] have reported the influence of the ledge thickness and of the surface charges on the device performance and its impact on reliability.
Palankovski et al. [149] have addressed these critical modelling issues for III V devices based on GaAs, AlAs, InAs, InP and GaP, their ternary alloys and non-ideal dielectrics in the 2D device simulator MINIMOS-NT [150]. Various important physical effects, such as BGN [151], surface recombination and self-heating, are taken into account. A new universal low field mobility model based on MC simulations, distinguishing...
