Bipolar complementary metal-oxide-semiconductor (BiCMOS) processes can be considered as the most general solution for RF products, as they combine the mature manufacturing tools of CMOS with the speed and drive capabilities of silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). HBTs in turn are major contenders for partially filling the terahertz gap, which describes the range in which the frequencies generated by transistors and lasers do not overlap (approximately 0.3 THz to 30 THz). To evaluate the capabilities of such future devices, a reliable prediction methodology is desirable. Using a heterogeneous set of simulation tools and approaches allows to achieve this goal successively and is beneficial for troubleshooting. Various scientific fields are combined, such as technology computer-aided design (TCAD), compact modeling and parameter extraction. To create a foundation for the simulation environment and to ensure reproducibility, the used material models of the hydrodynamic and drift-diffusion approaches are introduced in the beginning of this thesis. The physical models are mainly based on literature data of Monte Carlo (MC) or deterministic simulations of the Boltzmann transport equation (BTE). However, the TCAD deck must be calibrated on measurement data too for a reliable performance prediction of HBTs. The corresponding calibration approach is based on measurements of an advanced SiGe HBT technology for which a technology-specific parameter set of the HICUM/L2 compact model is extracted for the high-speed, medium-voltage and high-voltage transistor versions. With the help of the results, one-dimensional transistor characteristics are generated that serve as reference for the doping profile and model calibration. By performing elaborate comparisons between measurement-based reference data and simulations, the thesis advances the state-of-the-art of TCAD-based predictions and proofs the feasibility of the approach. Finally, the performance of a future technology in 28 nm is predicted by applying the heterogeneous methodology. On the basis of the TCAD results, bottlenecks of the technology are identified.
The semiconductor industry is a fundamental building block of the new economy, there is no area of modern life untouched by the progress of nanoelectronics. The electronic chip is becoming an ever-increasing portion of system solutions, starting initially from less than 5% in the 1970 microcomputer era, to more than 60% of the final cost of a mobile telephone, 50% of the price of a personal computer (representing nearly 100% of the functionalities) and 30% of the price of a monitor in the early 2000's. Interest in utilizing the (sub-)mm-wave frequency spectrum for commercial and research applications has also been steadily increasing. Such applications, which constitute a diverse but sizeable future market, span a large variety of areas such as health, material science, mass transit, industrial automation, communications, and space exploration. Silicon-Germanium Heterojunction Bipolar Transistors for mm-Wave Systems Technology, Modeling and Circuit Applications provides an overview of results of the DOTSEVEN EU research project, and as such focusses on key material developments for mm-Wave Device Technology. It starts with the motivation at the beginning of the project and a summary of its major achievements. The subsequent chapters provide a detailed description of the obtained research results in the various areas of process development, device simulation, compact device modeling, experimental characterization, reliability, (sub-)mm-wave circuit design and systems.
The trend in modern electronics towards ever higher frequencies of operation and complexity as well as power efficiency requires a whole palette of different technologies to be available to circuit designers for various applications. While MOSFETs dominate the digital world, they have apparently reached their top analogue performance around the 65nm node. Emerging technologies such as CNTFETs offer excellent properties such as very high linearity and speed in theory, but have yet to deliver on those promises in practice. Heterojunction bipolar transistors (HBTs), on the other hand, offer a number of key advantages over competing technologies: A very high transconductance and therefore a relatively low impact of a load impedance on the transistor operation, a high transit frequency and maximum frequency of oscillation at a comparatively relaxed feature size and favorable noise characteristics. Like all semiconductor devices, HBTs can be fabricated in diferent semiconductor materials. The most common are SiGe HBTs, which even today reach values above (ft; fmax) = (300; 500) GHz and are projected to eventually reach the THz range. However, HBTs fabricated in III-V materials offer a versatile alternative. Depending on the materials that are used, III-V HBTs can be the fastest available bipolar transistors (competing only with HEMTs, also fabricated in III-V materials, for the title of fastest available transistors overall), offer very high breakdown voltages and therefore excellent power-handling capability, show good linearity or low noise figures at high frequencies. Typical applications for III-V HBTs include handset PAs, high-effciency and high-speed amplifiers as well as high-speed oscillators . Overall, III-V-based HBTs and especially InP HBTs are excellent candidates for future high-speed communication circuits. The goal of this work is to include important effects occurring in III-V materials in a compact model for circuit design in a physical, yet intuitive way in order to aid deployment of III-V HBTs in prototypes and products. Additionally, the parameter extraction procedure for the compact model is described and analyzed in detail so an accurate, physics-based parameter set can be obtained. Finally, the agreement of the model with measurements is demonstrated for three different III-V HBT processes.