Communication and information systems are subject to rapid and highly
so- phisticated changes. Currently semiconductor heterostructure
devices, such as Heterojunction Bipolar Transistors (HBTs) and High
Electron Mobility Transis- tors (HEMTs), are among the fastest and most
advanced high-frequency devices. They satisfy the requirements for low
power consumption, medium integration, low cost in large quantities, and
high-speed operation capabilities in circuits. In the very
high-frequency range, cut-off frequencies up to 500 GHz [557] have
been reported on the device level. HEMTs and HBTs are very suitable for
high- efficiency power amplifiers at 900 MHz as well as for data rates
higher than 100 Gbitfs for long-range communication and thus cover a
broad range of appli- cations. To cope with explosive development costs
and the competition of today's semicon- ductor industry, Technology
Computer-Aided Design (TCAD) methodologies are used extensively in
development and production. As of 2003, III-V semiconductor HEMT and HBT
micrometer and millimeter-wave integrated circuits (MICs and MMICs) are
available on six-inch GaAs wafers. SiGe HBT circuits, as part of the
CMOS technology on eight-inch wafers, are in volume production.
Simulation tools for technology, devices, and circuits reduce expensive
technological efforts. This book focuses on the application of
simulation software to heterostructure devices with respect to
industrial applications. In particular, a detailed discussion of
physical modeling for a great variety of materials is presented.