Papers by Keyword: Microelectronics

Abstract: Multilayered electronic components, typically of heterogeneous materials, delaminate under thermal and mechanical loading. A phenomenological model focused on modeling the shape of such interface cracks close to corners in layered interconnect structures for calculating the critical stress for steady-state propagation has been developed. The crack propagation is investigated by estimating the fracture mechanics parameters that include the strain energy release rate, crack front profiles and the three-dimensional mode-mixity along the crack front. The developed numerical approach for the calculation of fracture mechanical properties has been validated with three-dimensional models for varying crack front shapes. A custom quantitative approach was formulated based on the finite element method with iterative adjustment of the crack front to estimate the critical delamination stress as a function of the fracture criterion and corner angles.

Abstract: Packaging high power radio frequency integrated circuits (RFICs) in low temperature cofired ceramic (LTCC) presents many challenges. Within the constraints of LTCC fabrication, the design must provide the usual electrical isolation and interconnections required to package the IC, with additional consideration given to RF isolation and thermal management. While iterative design and prototyping is an option for developing RFIC packaging, it would be expensive and most likely unsuccessful due to the complexity of the problem. To facilitate and optimize package design, thermal and mechanical simulations were used to understand and control the critical parameters in LTCC package design. The models were validated through comparisons to experimental results. This paper summarizes an experimentally-validated modeling approach to RFIC package design, and presents some results and key findings.

Abstract: Micro-electromechanical systems is called MEMS for short, it is the product of mutual integration for the micro-electronics and micro-mechanics, which covers mechanical, electrical, physical, biological and other modern technology. MEMS packaging is a key technology that has been developed based on electronic package technology. In order to strengthen the development of packaging process of MEMS, in particular, which are low cost, materials and packaging technology and has an ideal effect. The characteristics of MEMS packaging technology based on MEMS technologies are introduced, and the future development tendency and application of MEMS device packaging are previewed in this dissertation.

Abstract: Heterostructure device concepts promise several advantages in micro- and optoelectronics. From the material point of view, the main obstacle to be overcome is the large lattice mismatch of silicon based heterostructures. One of the best of them, silicon germanium (SiGe) is lattice mismatched to silicon by up to 4% depending on its Ge content. Basic investigations on strained layer growth, interface properties, and deviation from equilibrium are done with SiGe / Si heterostructures. Early results are discussed in context with our recent understanding. The application focus of this review is devoted to micro- and optoelectronic devices which could be fabricated after solving or understanding the basic interface problems. This includes devices already in production, and those in emerging fields for inclusion in the next generation of integrated circuits, as well as a selection of future device concepts with high merits to be proven in experiment.

Abstract: Microelectronics is a central area within information technology, which is still one of the most important global technologies. It will be shown that the development of integrated circuits is based on a long and fascinating history, which is unique in modern time. Yet, the fantastic growth in semiconductor electronics is due to a unique combination of basic conceptional advances, the perfection of new materials and the development of new device principles. A brief survey of the development of microelectronics is given by not only focusing on the history of microelectronics but also taking into account materials and market aspects. Since microelectronics is an extremely complex area, a few criteria and reference points for integrated circuits are given. Thereafter, some examples are presented indicating the rapidly changing state-of-the-art. It will be shown that the development of material science within the area of microelectronics is not always driven by scientific curiosity but often by arbitrary and not always obvious preferences. After a short discussion of the performance advantages and disadvantages of germanium, silicon and III-V compound semiconductors, the SiGe heterojunction bipolar transistor is taken as an example for demonstrating a few important differences in the performance of all-silicon devices with regard to silicon-based heterojunction devices in general. In conclusion, the impact of human enterprise and research policy on the development of microelectronics is briefly discussed.

Abstract: This paper reviews present day test structures and illustrates how they have evolved to a continuously changing technology. Structures for measuring resistivity, contact resistance, feature dimensions and overlay errors are presented as are MEMS (Micro-Electro-Mechanical Systems)/microsystems specific devices.

Abstract: An integrated sensor method is used to measure interfacial temperature profiles with an ultrasonic friction test process. The profiles are compared to numerical results obtained by a transient thermal 2D axisymmetric finite elements (FE) analysis. In the experiments, the 50 $m diameter gold balls used in wire bonding are deformed by the capillary tool during impacting on the flat surface of a silicon chip (contact zone). The deformed balls then are pressed onto the SiO2 layer on the chip and vibrated with various amplitudes of 128 kHz ultrasonics. The 52 $m diameter contact zone is surrounded in 14 $m distance by a 50
aluminum resistor which is used as a resistive temperature detector. Temperature increases of typically 0.18 K and up to 0.3 K are measured by the sensor close to the heat source at the contact zone, corresponding to 3.1 K and 5.2 K at the interface as suggested by the FE model. With typical bonding parameters, the contact zone friction power is determined to be 4.4 mW which is less than 2 % of the electrical energy delivered to the used ultrasonic transducer type.

Abstract: Self-formation concept as a generalization of the huge number of technologies in microelectronics was defined. Self-formation as irreversible evolution, causing self-increasing of an object complexity, is presented. Differential equation method allows description of evolution of any figures contour. Numerical model of self-formation in essence is a cellular automata of the second kind. Neither analytical nor numerical models did not involve causes of contour evolution. However causes of evolution are hidden in interactions of parameters which approximate an object and ambient materials. On the basis of above-mentioned factors, the right-dimensional topological space was created. It is the Cartesian product of the eight sets, including three Euclidean space axes, four parameter axes (defining parameters of the Euclidean points and interaction matrix) and time axis. Self-formation is a result of non-homogeneous mapping sequence in time. On the other hand non-homeomorpheous mapping indicates irreversibility of an evolution. Evolution is irreversible in time if only the object either contains the peculiar points or they arise under evolution. Therefore an interaction, defining the figure evolution out-side, does not return the object to initial state after its diversion inside and can implicate the complexity increasing. The new self-formation technologies for electron devices and integrated circuits manufacturing were carried out. Topological approach allows analysis and synthesis of real world structures, known in the areas of microelectronics, nanotechnology, photovoltaics and fuel cell technology, possibly in living world (genes, cells, organs, organism) as well. Problems remaining to be investigated are presented.