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Über dieses Buch

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.

Inhaltsverzeichnis

Frontmatter

1. Introduction

Abstract
Communication and information systems are subject to rapid and highly sophisticated changes. Currently semiconductor heterostructure devices, such as Heterojunction Bipolar Transistors (HBTs) and High Electron Mobility Transistors (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 verysuitable for high efficiency power amplifiers at 900 MHz as well as for data rates higher than 100 Gbit/sfor long-range communication and thus cover abroad rangeof applications.
Vassil Palankovski, Rüdiger Quay

2. State-of-the-Art of Materials, Device Modeling, and RF Devices

Abstract
Based on their electrical properties, solids can be classified as conductors, insulators, or semiconductors. Amorphous solids have little or no regular geometric arrangement of their atoms in space and therefore cannot be easily studied. Crystalline solids have a perfect periodic arrangement of atoms, which allows them to be easily analyzed. Polycrystalline solids have atomic arrangements between these two extremes. Semiconductor materials are nearly perfect crystalline solids with a small amount of imperfections, such as impurity atoms, lattice vacancies, or dislocations, which can be intentionally introduced to alter their electrical characteristics[305].
Vassil Palankovski, Rüdiger Quay

3. Physical Models

Abstract
Transport of charged carriers in semiconductor devices can be described by the Boltzmann transport equation, which provides a semiclassical description. In this context, semiclassical means that the transport is described by the classical equations of motion, whereas the scattering events, which are assumed to happen instantaneously, are described by the laws of quantum mechanics. This formulation of carrier transport is generally considered to be valid for modern devices.
Vassil Palankovski, Rüdiger Quay

4. RF Parameter Extraction for HEMTs and HBTs

Abstract
This chapter addresses the extraction of RF quantities such as Y- and related parameters, derived quantities such as stability factors and cut-off frequencies, and, last but not least, small-signal equivalent circuit elements for various topologies. It further provides a view of the physical understanding of the bias dependence of small-signal equivalent circuit elements in HEMTs and HBTs in analytcial models and TCAD approaches.
Vassil Palankovski, Rüdiger Quay

5. Heterojunction Bipolar Transistors

Abstract
Heterojunction Bipolar Transistors (HBTs) are an advanced development of the Bipolar Junction Transistors (BJTs). The basic principles of operation of bipolar transistors are explained in detail elsewhere, e.g. in [305, 496, 570].
Vassil Palankovski, Rüdiger Quay

6. High Electron Mobility Transistors

Abstract
High Electron Mobility Transistors(HEMTs) [340] are an advanced modification of the simple bulk FET, such as the MEtal Semiconductors Field Effect Transistor (MESFET). Typically, a semiconductor material (barrier) with a comparably wider bandgap is grown on top of a semiconductor material with a higher mobility and comparably lower bandgap. If the bandgap alignment of the two materials is appropriately chosen, a channel forms due solely to the alignmentof the band edges and not, as for silicon MOSFETs or III-V MESFETs [460], due to an oxide/semiconductor interface or doping profiles. The channel material is not intentionally doped.
Vassil Palankovski, Rüdiger Quay

7. Novel Devices

Abstract
This chapter provides a glimpse of emerging approaches for new heterostructure high-speed and high-power devices.
Vassil Palankovski, Rüdiger Quay

Backmatter

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