73 research outputs found
Architectural Theory at Two Speeds
No full textThe article is a presentation of the ethnographic method applied to architecture. The author explains how “slow ethnographers” work when they deal with a building, by focusing on the case of namBa HIPS building by Shin Takamatsu, in Osaka. “Slow” ethnography offers an alternative to “quick theory” intended as a critical theory of architecture that is based on the observation and interpretation of a static object as related to the consolidated spheres of theory and history. Yaneva’s proposal is to start back from the experience of space and objects as built over time: architecture is a process made of cumulative interactions, that unfolds from the design phase to the experience of those who inhabit it, through a continuous intertwinement of human and non-human entities. The study offers itself as a diachronic operation framing the very project as an anticipation of the many velocities to which the project’s transactions are submitted, just as the uses of built space will be: «While working with the speeds, [the architect] does not express or symbolize anything; he simply immerses into the tempo of design and adjusts its different rhythms with engineers, contractors and investors
The Making of a Building : a pragmatist approach to architecture
No full textHow do architects learn about a building-to-be? How does a building emerge and gain reality in the model shop, in scaling, in option making, in architects' - and engineers' - discussions, in public presentations? What does it mean to design? What does it mean to add a building to the city? Drawing on rare ethnographical material of architects at work at the Office for Metropolitan Architecture (OMA) of Rem Koolhaas in Rotterdam in the period 2001-4, this book offers a novel account of the social and cognitive complexity of architecture in the making. The author dismisses both stylistic periodization and socio-political constructivist methods as being inadequate to the task of understanding the dynamic process of how architects generate design through space and materiality, instead showcasing the potentials of the pragmatist approach as a research tool in the field of architecture. Offering a new way of understanding architecture as practice that takes place within the interactive networks of human and non-human actors, the book also tells the intriguing story of the extensions of the Whitney Museum of American Art in New York
Challenges to Optimize Charge Trapping Non-Volatile Flash Memory Cells: A Case Study of HfO2/Al2O3 Nanolaminated Stacks
No full textThe requirements for ever-increasing volumes of data storage have urged intensive studies to find feasible means to satisfy them. In the long run, new device concepts and technologies that overcome the limitations of traditional CMOS-based memory cells will be needed and adopted. In the meantime, there are still innovations within the current CMOS technology, which could be implemented to improve the data storage ability of memory cells—e.g., replacement of the current dominant floating gate non-volatile memory (NVM) by a charge trapping memory. The latter offers better operation characteristics, e.g., improved retention and endurance, lower power consumption, higher program/erase (P/E) speed and allows vertical stacking. This work provides an overview of our systematic studies of charge-trapping memory cells with a HfO2/Al2O3-based charge-trapping layer prepared by atomic layer deposition (ALD). The possibility to tailor density, energy, and spatial distributions of charge storage traps by the introduction of Al in HfO2 is demonstrated. The impact of the charge trapping layer composition, annealing process, material and thickness of tunneling oxide on the memory windows, and retention and endurance characteristics of the structures are considered. Challenges to optimizing the composition and technology of charge-trapping memory cells toward meeting the requirements for high density of trapped charge and reliable storage with a negligible loss of charges in the CTF memory cell are discussed. We also outline the perspectives and opportunities for further research and innovations enabled by charge-trapping HfO2/Al2O3-based stacks
Investigation of high-k dielectric stacks by C-AFM: Advantages, limitations, and possible applications
No full textS.79-118This chapter demonstrates the capability and the accuracy of tunneling atomic force microscopy (TUNA) and conductive atomic force microscopy (C-AFM) by comparing measurement results with data from conventional macroscopic current-voltage (I-V) methods. C-AFM/TUNA characterization complements conventional I-V measurements on metal-insulator-semiconductor (MIS) structures by accessing higher current densities. The chapter also addresses several limitations (e.g., parasitic capacitances in the pF range resulting from the cantilever of the probe and the probe holder and displacement current) which influence sensitivity and may be a possible obstacle for correct analysis of experimental data. The feasibility of these techniques and their ability to study phenomena at nanoscale is then demonstrated by several applications. The chapter further shows the great potential of C-AFM/TUNA technique to investigate changes in high-k film morphology. It presents an approach to evaluate the thickness of the thin interfacial SiO2 layer in high-k stacks and its change with the processing conditions
Investigation of High-<i>k</i> Dielectric Stacks by C-AFM: Advantages, Limitations, and Possible Applications
No full text
CONSIDERATION OF CONDUCTION MECHANISMS IN HIGH-K DIELECTRIC STACKS AS A TOOL TO STUDY ELECTRICALLY ACTIVE DEFECTS
No full textIn this paper conduction mechanisms which could govern the electron transport through high-k dielectrics are summarized. The influence of various factors – the type of high-k dielectric and its thickness; the doping with a certain element; the type of metal electrode as well as the measurement conditions (bias, polarity and temperature), on the leakage currents and dominant conduction mechanisms have been considered. Practical hints how to consider different conduction mechanisms and to differentiate between them are given. The paper presents an approach to assess important trap parameters from investigation of dominant conduction mechanisms
HYSTERESIS-LIKE FLATBAND VOLTAGE INSTABILITIES IN Al/Ta2O5-SiO2/Si STRUCTURES AND THEIR CONNECTION WITH J-V CHARACTERISTICS
No full textFlatband and current-voltage instabilities in unstressed Al/Ta2O5-SiO2/Si structures were studied in details. It has been found that, after an initial run left on fresh samples, both C-V and J-V characteristics exhibit repeatable patterns. Precisely repeatable counterclockwise hysteresis-like loop in C-V characteristics occurs, while no significant hysteretic behaviour is observed in static J-V characteristics. The reduced instability in J-V characteristics is explained by mutual compensation of two opposite effects owing to the presence of trapped positive charges on slow traps in the interfacial SiO2-like layer: (i) flatband voltage shift and (ii) lowering of Fowler-Nordheim tunnelling barrier for holes injected from the Si substrate. Correct determination of equivalent oxide thickness and fast interface state densities requires using the C-V curves obtained during the runs right, because progressive trapping on slow states occurs during the runs left. Value of the oxide charge is to be determined using the value of the flatband voltage obtained from the run left (after an initial run right), since it corresponds to the state of empty slow traps.</jats:p
Consideration of conduction mechanisms in high-k dielectric stacks as a tool to study electrically active defects
No full textIn this paper conduction mechanisms which could govern the electron transport
through high-k dielectrics are summarized. The influence of various factors -
the type of high-k dielectric and its thickness; the doping with a certain
element; the type of metal electrode as well as the measurement conditions
(bias, polarity and temperature), on the leakage currents and dominant
conduction mechanisms have been considered. Practical hints how to consider
different conduction mechanisms and to differentiate between them are given.
The paper presents an approach to assess important trap parameters from
investigation of dominant conduction mechanisms.</jats:p
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