structure and properties of unidirectionally reinforced pan-resin based carbon-carbon composites

a study has been made of the structure and properties of in-house fabricated, unidirectionally reinforced polyacrylonitrile (pan) fibre-phenolic plus furfuryl alcohol matrix carbon/carbon (c/c) composites comprising surface-treated (st) as well as non-surface-treated (nst) carbon fibres. the composites are subjected to a final heat treatm..

fabrication of silicon nanostructures with a scanning tunneling microscope

a technique is presented for fabricating si nanostructures with a scanning tunneling microscope operated in air. the process involves the direct chemical modification of a h-passivated si(100) surface and a subsequent liquid etch. the chemically modified portions of the surface can withstand a deep (>100 nm) liquid etch of the unmodified ..

photo-excited dry cleaning for ulsi devices

the authors studied the reverse current in n/sup +/p junctions after photo-excited cleaning for samples fabricated by rie. silicon surfaces of a wafer contaminated during rie were etched by photo-excited dry cleaning using chlorine, after which the unexpectedly large junction leakage current often occurring after wet cleaning alone was co..

laser materials processing applications at lawrence livermore national laboratory

high power and high radiance laser technologies developed at lawrence livermore national laboratory (llnl) such as copper-vapor lasers, solid-state slab lasers, dye lasers, harmonic wavelength conversion of these lasers, and fiber optic delivery systems show great promise for material processing tasks. evaluation of models suggests signif..

surface treatment of a-axis euba/sub 2/cu/sub 3/o/sub 7-y/ thin films by an electron cyclotron resonance ion beam

an electron cyclotron resonance (ecr) ion beam has been utilized for a developing surface cleaning process of high-t/sub c/ superconducting thin films. by means of silver-contact resistivity measurements, and ex situ surface analysis using x-ray photoelectron spectroscopy (xps) and reflection high-energy electron diffraction (rheed), the ..

characterisation of cdte-based epitaxial solar cell structures fabricated by movpe

this work has principally been concerned with the fabrication and characterisation of a number of cdte-based p-n and p-i-n solar cells by movpe, namely' (i) the n-cds/p-cdte cell on (0001)cds, (ii) the n-cdte/p-znte cell on (100)cdte, (iii) the p-znte/i-cdte/n-cds cell on (0001)cds and (iv) the p-znte/i-cdte/n-gaas cell on (100)gaas. the ..

development of an optical-fibre sensor using a functional membrane

a new functional membrane which changes its reflectance spectra according to the ph of the test solution is described. a chloromethylstyrene (cms)/methylmethacrylate (mma) copolymer was chosen as the base for the immobilized reagent. a basic ion-exchanger was then added to the cms/mma copolymer. bromothymol blue (btb) was then immobilized..

dry surface cleaning of plasma-etched high electron mobility transistors

fabrication of submicron high electron mobility transistors (hemts) involves dry etch removal of gaas from an underlying algaas or ingaas stop layer. the etch selectivity is achieved by formation of alf/sub 3/ on algaas, or incl/sub 3/ and inf/sub 3/ on ingaas, which must be removed before processing can proceed. wet chemical cleaning has..

ulsi reliability through ultraclean processing

the importance of ultraclean processing in establishing advanced process technologies for deep submicron ulsi fabrication is discussed. the most essential requirement for the process technologies is the simultaneous fulfilment of the three principles of ultraclean technology' ultraclean wafer surface, ultraclean processing environment, an..

compression failure in reduced adhesion fiber laminates

the compressive strength of fiber composites is of key interest in many strength critical composite structures, due to the generally lower failure values relative to tension dominated stress states. the general understanding of the factors that control compression failure is quite rudimentary, and as a consequence strength controlled desi..