960 research outputs found
Technologies for 3D Heterogeneous Integration
3D-Integration is a promising technology towards higher interconnect
densities and shorter wiring lengths between multiple chip stacks, thus
achieving a very high performance level combined with low power consumption.
This technology also offers the possibility to build up systems with high
complexity just by combining devices of different technologies. For ultra thin
silicon is the base of this integration technology, the fundamental processing
steps will be described, as well as appropriate handling concepts. Three main
concepts for 3D integration have been developed at IZM. The approach with the
greatest flexibility called Inter Chip Via - Solid Liquid Interdiffusion
(ICV-SLID) is introduced. This is a chip-to-wafer stacking technology which
combines the advantages of the Inter Chip Via (ICV) process and the
solid-liquid-interdiffusion technique (SLID) of copper and tin. The fully
modular ICV-SLID concept allows the formation of multiple device stacks. A test
chip was designed and the total process sequence of the ICV-SLID technology for
the realization of a three-layer chip-to-wafer stack was demonstrated. The
proposed wafer-level 3D integration concept has the potential for low cost
fabrication of multi-layer high-performance 3D-SoCs and is well suited as a
replacement for embedded technologies based on monolithic integration. To
address yield issues a wafer-level chip-scale handling is presented as well, to
select known-good dies and work on them with wafer-level process sequences
before joining them to integrated stacks.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
Quantum and Classical Chaos in Kicked Coupled Jaynes-Cummings Cavities
We consider two Jaynes-Cummings cavities coupled periodically with a photon
hopping term. The semi-classical phase space is chaotic, with regions of
stability over some ranges of the parameters. The quantum case exhibits dynamic
localization and dynamic tunneling between classically forbidden regions. We
explore the correspondence between the classical and quantum phase space and
propose a scheme for implementing the system experimentally
Chaos assisted adiabatic passage
We study the exact dynamics underlying stimulated Raman adiabatic passage
(STIRAP) for a particle in a multi-level anharmonic system (the infinite
square-well) driven by two sequential laser pulses, each with constant carrier
frequency. In phase space regions where the laser pulses create chaos, the
particle can be transferred coherently into energy states different from those
predicted by traditional STIRAP. It appears that a transition to chaos can
provide a new tool to control the outcome of STIRAP
A new model-discriminant training algorithm for hybrid NN-HMM systems
This paper describes a hybrid system for continuous speech recognition consisting of a neural network (NN) and a hidden Markov model (HMM). The system is based on a multilayer perceptron, which approximates the a-posteriori probability of a sequence of states, derived from semi-continuous hidden Markov models. The classification is based on a total score for each hybrid model, attained from a Viterbi search on the state probabilities. Due to the unintended discrimination between the states in each model, a new training algorithm for the hybrid neural networks is presented. The utilized error function approximates the misclassification rate of the hybrid system. The discriminance between the correct and the incorrect models is optimized during the training by the "Generalized Probabilistic Descent Algorithm\u27;, resulting in a minimum classification error. No explicit target values for the neural net output nodes are used, as in the usual backpropagation algorithm with a quadratic error function. In basic experiments up to 56% recognition rate were achieved on a vowel classification task and up to 69 % on a consonant cluster classification task
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