TcSUH EventS
Special Seminar
Studies of Growth for BST Ferroelectric Oxide Thin Films
by: Prof. Yanrong Li
Date: Friday April 15, 2005
Time: 4:00 pm – 5:00 pm
Location: Houston Science Center – Building 593 — Room 102
Overview
We have systematically investigated the epitaxial behavior, microstructures, and dielectric properties of ferroelectric (Ba,Sr)TiO3 thin films on various substrates grown by pulsed laser ablation and laser MBE. We have focused on the film growth mechanisms, low temperature crystallization, and buffer- layer-induced high oriented film growth as well as oxide superlattices. Microstructural studies from x-ray diffraction, rocking curve measurements, and electron microscopy reveal that the films have excellent epitaxial behavior with good single crystallinity and sharp interfacial structures and smooth surface morphology for the films grown on substrate surfaces.
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Special Seminar
Manufacturability at the Nanoscale
by: Dr. Christie Marrian
Date: Thursday April 07, 2005
Time: 12:00 pm – 1:00 pm
Location: Houston Science Center – Building 593 — Room 102
Overview
Using the 2005 IBM Global Technology Outlook, I will describe the roadmap for device technology and manufacturing in the semiconductor industry. Looking beyond these roadmaps, I will discuss moving beyond our current methods of fabrication of nanoscale devices and circuits. These almost always rely on heroic efforts of nanofabrication that are inappropriate for anything other than research. To achieve, at the nanoscale, any level of volume manufacturing requires more than extensions of the paradigms practiced today. We must look to Nanotechnology for help in overcoming this challenge as to fail to do so will consign nanostructure science and technology to be a mere intellectual curiosity.
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Special Seminar
Recent Issues in Data Storage
by: Prof. Erik Svedberg
Date: Thursday April 07, 2005
Time: 10:00 am – 11:00 am
Location: Houston Science Center – Building 593 — Room 102
Overview
The “trilemma” of data-storage is becoming more challenging as the packing density of information continues to increase on disc drives. We are today aiming to reach a density of 1Tbit/in2. The conflicting magnetic requirements while shrinking the bit size will be described in this presentation and I will visit some of the interesting challenges in materials science and measurement technology encountered during my last five years working in this area. The presentation will touch upon AFM/MFM measurements used for determination of signal-to-noise ratios and data aging. There is always a need to “see” what you have recorded, not only to receive a feedback signal from the system under study. Nano-particles versus grains in thin films and statistical size analysis will be included as it is an important aspect for future technologies. Today grain size distributions rely largely on SEM and TEM images that provide too little statistical material. Electroplated nano-junctions present the possibility of novel properties that are e.g. useful in sensors for reading stored information. As the bit size shrinks the magnetic signal is reduced and there is a search for more sensitive detectors. Combinatorial approaches to material science and x-ray diffraction (XRD) texture determination of important magnetic materials, such as FePt, will also be discussed. The complex factors determining the magnetic thin film properties can be initially screened and optimized in ways similar to advanced drug discovery.
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Special Seminar
Thin Film Hetero Structure Solid Oxide Fuel Cell
by: Prof. Alex Ignatiev
Date: Thursday March 24, 2005
Time: 12:00 pm – 1:00 pm
Location: Houston Science Center – Building 593 — Room 102
Overview
A thin film solid oxide fuel cell (TFSOFC) with significantly reduced operating temperature has been developed based on thin film deposition and photolithographic processing. The unique thin film SOFC design incorporates a thin film (<1 micron) oxide electrolyte, deposited on a nickel foil substrate by pulsed laser deposition and MOCVD, and deposition of a micro porous thin film conducting oxide La0.5Sr0.5COO3 (LSCO) cathode on top of the electrolyte thin film forming the fuel cell heterostructure. The nickel substrate is then made porous (and thus becomes the cell anode) by photolithographic patterning and etching. This thin film SOFC structure results in operating temperatures as low as 450°C, which now allows for the utilization of more standard cell support materials and also results in much reduced thermal stress and thermal degradation. The thin film SOFC has stably operated in a temperature range of 450-570°C, significantly lower than bulk SOFC's, and has yielded a maximum output power density of ~110mW/cm2 in that temperature range. The low operating temperatures coupled with the nickel anode also allow for the direct conversion of hydrocarbons, especially methane and methanol without the problem of coking, thus resulting in a true self-reforming SOFC. The thin film character of the thin film SOFC when integrated with thin film interconnects is expected to result in a high power to volume ratio (= 10 W/cm3), which will be important in a variety of power applications.
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Special Seminar
Computational Materials for CMOS Technology
by: Prof. Alex Demkov
Date: Thursday February 03, 2005
Time: 4:00 pm – 5:00 pm
Location: Houston Science Center – Building 593 — Room 102
Overview
In order to continuously improve the transistor performance the semiconductor industry is exploring a variety of novel structures and materials that only recently were considered only in long-range R&D labs. Such systems include SOI, strained Si on SiGe, and high-k dielectrics for the gate along with pure metal gates instead of poly-Si, low-k dielectrics for ILD etc. Along with these revolutionary technologies, industry pays close attention to squeezing every bit of performance from the existing platforms, strain engineering and effects of shallow trenches is one example. Traditional TCAD tools often lack physical models capable of describing all these new systems, and atomic level modeling is being considered as an important tool in the mainstream semiconductor development. Thus the intrusion of “exotic materials†and significant developments of the atomic scale modeling over the past decade made it possible to derive value from a fairly academic discipline. In this talk I will show how the CMOS roadmap brings about a strange marriage of quantum mechanics and transistor manufacturing.
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