Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

scholarly journals Principles and Characteristics of Different EDM Processes in Machining Tool and Die Steels

2020 ◽  
Vol 10 (6) ◽  
pp. 2082 ◽  
Author(s):  
Jaber E. Abu Qudeiri ◽  
Aiman Zaiout ◽  
Abdel-Hamid I. Mourad ◽  
Mustufa Haider Abidi ◽  
Ahmed Elkaseer
Keyword(s):  
Large Scale ◽  
Removal Rate ◽  
Surface Characteristics ◽  
Future Research ◽  
Process Conditions ◽  
Process Performance ◽  
Die Steels ◽  
Wide Range ◽  
Complex Shapes ◽  
Manufacturing Technologies

Electric discharge machining (EDM) is one of the most efficient manufacturing technologies used in highly accurate processing of all electrically conductive materials irrespective of their mechanical properties. It is a non-contact thermal energy process applied to a wide range of applications, such as in the aerospace, automotive, tools, molds and dies, and surgical implements, especially for the hard-to-cut materials with simple or complex shapes and geometries. Applications to molds, tools, and dies are among the large-scale initial applications of this process. Machining these items is especially difficult as they are made of hard-to-machine materials, they have very complex shapes of high accuracy, and their surface characteristics are sensitive to machining conditions. The review of this kind with an emphasis on tool and die materials is extremely useful to relevant professions, practitioners, and researchers. This review provides an overview of the studies related to EDM with regard to selection of the process, material, and operating parameters, the effect on responses, various process variants, and new techniques adopted to enhance process performance. This paper reviews research studies on the EDM of different grades of tool steel materials. This article (i) pans out the reported literature in a modular manner with a focus on experimental and theoretical studies aimed at improving process performance, including material removal rate, surface quality, and tool wear rate, among others, (ii) examines evaluation models and techniques used to determine process conditions, and (iii) discusses the developments in EDM and outlines the trends for future research. The conclusion section of the article carves out precise highlights and gaps from each section, thus making the article easy to navigate and extremely useful to the related research community.

scholarly journals Transmission electron microscopy study of very low-grade metamorphic evolution in Neoproterozoic pelites of the Puncoviscana formation (Cordillera Oriental, NW Argentina)

Clay Minerals ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 459-481 ◽  
Author(s):  
M. Do Campo ◽  
F. Nieto
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Long Range ◽  
Regional Metamorphism ◽  
Analytical Electron Microscopy ◽  
Crystallinity Index ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Low Grade ◽  
Wide Range

AbstractThe Puncoviscana Formation, largely cropping out in NW Argentina, is mainly composed of a pelite-greywacke turbidite sequence affected by incipient regional metamorphism and polyphase deformation. Metapelites, composed mainly of quartz, albite, dioctahedral mica and chlorite, were sampled in the Lules-Puncoviscana and Choromoro belts. Lattice-fringe images, selected area electron diffraction and analytical electron microscopy analyses, coupled with previous data from white mica crystallinity index, indicate a state of reaction progress for Puncoviscana slates consistent with medium anchizone- to epizone-grade metamorphism. The 2Mpolytype prevails in dioctahedral micas, coexisting in a few cases with the 1Mdpolytype as a consequence of lack of equilibrium. The 2Mpolytype coexists with 3Tin two slates and long-range four-layer and ten-layer stacking sequences were identified in another sample. Samples with 3Tand long-range stacking sequences presentbvalues characteristic of intermediate–high pressure metamorphism and ordered chlorites (1L, 2L, 3Land 7L) prevail.Based on the Si contents of dioctahedral micas and considering peak temperatures of ∼350 –400ºC, pressures from 5 kbar and 5 –7 kbar were derived for metapelites from the Lules- Puncoviscana and Choromoro belts, respectively. These values agree with facies series derived from thebvalues. Micas with a wide range of phengitic substitution, as evidenced by Fe + Mg and Si contents, coexist. These variations could not arise from the disturbing effect of detrital white K-mica because TEM evidence indicates that they are absent or represent <10% of the mica population. Thus, compositional variations suggest that dioctahedral micas of individual slates crystallized at different pressure conditions in response to theP-Tpath of the metamorphism. Moreover, in several biotite-free slates the illite crystallinity (IC) values lead to an underestimation of the metamorphic grade attained in these rocks.The coexistence of IC corresponding to anchizone and the occurrence of biotite in some slates and felsic metavolcanic rocks intercalated in the Puncoviscana metasediments are interpreted to be the result of a metamorphic path including a relatively high-pressure/ low-temperature (HP/LT) event, followed by a lower-pressure overprint possibly at higher temperatures than the HP/LTevent. Small micas formed during the high-pressure stage would prevail in the <2 mm fraction, producing anchizone IC.

Floral morphology and pollination system in the native Australian perennial pasture legume Cullen australasicum (syn. Psoralea australasica)

2010 ◽  
Vol 61 (12) ◽  
pp. 1001 ◽  
Author(s):  
Yan-Jing Wang ◽  
Ramakrishnan M. Nair ◽  
Chun-Sheng Mu ◽  
Ian S. Dundas
Keyword(s):  
Floral Morphology ◽  
South Australia ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Stigma Receptivity ◽  
Wide Range ◽  
Electron Microscopes ◽  
Perennial Legume ◽  
Stigma Morphology ◽  
Scanning Electron

Cullen australasicum (syn. Psoralea australasica) is a native perennial legume with potential in the low-rainfall wheatbelt of southern Australia. The objective of this study was to investigate the reproductive biology of C. australasicum utilising five accessions. Glasshouse and field pollination experiments were conducted in Adelaide, South Australia. Floral morphology, stigma receptivity and pollen : ovule ratios were determined. Pollen tube growth and stigma morphology were examined using fluorescence and scanning electron microscopes. Glasshouse pollination studies indicated that four of the accessions showed the need for an external tripping agent to bring about pollination and that hand-tripping was the most efficient method. A scanning electron microscopy study revealed there are two types of stigmas in this species. Stigma receptivity was significantly lower at the early bud stage before anther dehiscence. The results show that C. australasicum is a self-compatible species comprising accessions with a wide range of outcrossing potential.

scholarly journals Micromechanical Process Integration and Material Optimization for High Performance Silicon-Germanium Bolometers

2012 ◽  
Vol 1437 ◽  
Author(s):  
Gunnar B. Malm ◽  
Mohammadreza Kolahdouz ◽  
Fredrik Forsberg ◽  
Niclas Roxhed ◽  
Frank Niklaus
Keyword(s):  
Integrated Circuits ◽  
Silicon Germanium ◽  
High Performance ◽  
Large Scale ◽  
Process Integration ◽  
Low Frequency ◽  
Single Layer ◽  
Sige Layer ◽  
Frequency Noise ◽  
Wide Range

ABSTRACTSemiconductor-based thermistors are very attractive sensor materials for uncooled thermal infrared (IR) bolometers. Very large scale heterogeneous integration of MEMS is an emerging technology that allows the integration of epitaxially grown, high-performance IR bolometer thermistor materials with pre-processed CMOS-based integrated circuits for the sensor read-out. Thermistor materials based on alternating silicon (Si) and silicon-germanium (SiGe) epitaxial layers have been demonstrated and their performance is continuously increasing. Compared to a single layer of silicon or SiGe, the temperature coefficient of resistance (TCR) can be strongly enhanced to about 3 %/K, by using thin alternating layers. In this paper we report on the optimization of alternating Si/SiGe layers by advanced physically based simulations, including quantum mechanical corrections. Our simulation framework provides reliable predictions for a wide range of SiGe layer compositions, including concentration gradients. Finally, our SiGe thermistor layers have been evaluated in terms of low-frequency noise performance, in order to optimize the bolometer detectivity.

Shallow Junction Formation by the Redistribution of Species Implanted into Cobalt Silicide

1987 ◽  
Vol 92 ◽  
Author(s):  
Brian M. Ditchek ◽  
Marvin Tabasky Marvin Tabasky ◽  
Emel S. Bulat
Keyword(s):  
Integrated Circuits ◽  
Sheet Resistance ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Large Scale ◽  
Lateral Diffusion ◽  
Rapid Thermal Anneal ◽  
Alignment Process ◽  
Circuits Vlsi ◽  
Recent Demonstration

Interest in CoSi2 as a metallization for very large scale integrated circuits (VLSI) has grown rapidly since the recent demonstration of a simple self-aligned process performed by rapid thermal annealing.1-4 Using a rapid thermal anneal (RTA) to directly silicide Co on Si yields smooth low-sheet-resistance films with little or no lateral diffusion and low contact resistance. In addition, it has been shown that rapid thermal annealing can result in reasonable quality epitaxial CoSi2 on (111) Si wafers.5 An important advantage of CoSi2 over the more commonly used TiSi2 metallization is the relative simplicity of its self-aligned silicidation process. Due to the low reactivity of Co with SiO2, a simple two-step self-alignment process is possible instead of the three-step process necessary with TiSi2.6 The primary disadvantage of CoSi2 is the amount of Si consumed for equal silicide sheet resistance. For example, to yield a silicide sheet resistance of 1.5 1/LD, Van den Hove 4 finds that compared to the TiSi, process, the CoSi, process would consume an additional 24 nm of Si. (This disadvantage can be minimized if very shallow junctions can be formed under the CoSi2.)

A Green Route to Hexagonal and Monoclinic BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) Nanocrystallites for Tailoring Luminescent Performance

2016 ◽  
Vol 16 (4) ◽  
pp. 3547-3556 ◽  
Author(s):  
Errui Yang ◽  
Guangshe Li ◽  
Yunlong Zheng ◽  
Liping Li
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Monoclinic Phase ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
Formation Mechanisms ◽  
Optical Integrated Circuits ◽  
Green Route ◽  
Potential Applications ◽  
Co Precipitation

Selective synthesis of specific phased nanomaterials via a green route is a promising yet challenging task. In the present work, the hexagonal and monoclinic phases of BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) were prepared via room temperature co-precipitation method. For adjusting the phase of the products, the prepared mediums selected were the most common solvents, i.e., water and ethanol. It was very important that the prepared mediums could be easily recycled and reused by evaporating the filtrate. The formation mechanisms of hexagonal in water and monoclinic in ethanol were investigated. Interestingly, the growth behaviors of these phases were quite distinct and thus gave rise to distinct morphology and particle size. The hexagonal phase possesses a rod-like morphology with diameters of 50–160 nm and lengths of 65–400 nm while the monoclinic phase consists of almost entirely irregular nanoparticles. Also, it was found that the bending and stretching vibrations of O–H and PO4 tetrahedra were quite different for the products prepared in water and ethanol. Moreover, it was found that the luminescence properties, including emission intensity, lifetime, quantum efficiency, and color, could be readily tailored through controlling the phase structures and microstructures. The results showed that the monoclinic phase exhibited superior luminescent performance to the hexagonal phase. The methodologies reported in this work were fundamentally important, which could be easily extended to large-scale synthesis of other phased nanomaterials for potential applications as electroluminescent devices, optical integrated circuits, or biomarkers.

scholarly journals Impact of Variation of Device Parameters on the Electrical Characteristics of Double-Gate Mosfets

2020 ◽  
Vol 9 (3) ◽  
pp. 3658-3661
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Field Effect Transistors ◽  
Oxide Semiconductor ◽  
Double Gate ◽  
Electrical Characteristics ◽  
Short Channel ◽  
Channel Effects ◽  
Circuits Vlsi ◽  
Logical Functions

Very large scale integrated circuits (VLSI) have been possible owing to the shrinking of metal-oxide semiconductor field-effect transistors (MOSFETs). By reducing the dimensions of the device it is possible to have high density on the chip. This increases the number of logical functions that can be implemented on a given dimension of the chip. Along with the advantages associated with the shrinking of the devices, it also has certain drawbacks commonly known as short-channel effects. Due to these effects, device characteristics deviate from its expected values. There are many techniques through which these deviations can be minimized. One of the promising and highly researched techniques these days is the use of Multi-gate (MG) transistors in VLSI. Double-gate (DG) transistor is one among MG transistors. In DG MOSFET, substrate is surrounded by gates from two opposite sides. This leads to more control over the channel electrons by the gate terminals. In this paper, the consequence of change of various device constraints on the electrical characteristics of the DG MOSFETs will be investigated. Through the results, one can know to what extent the electrical properties changes when the dimensions and/or material properties are changed. This will be very helpful in determining the maximum current associated with those dimensions of DG MOSFETs.

High Resolution Transmission Electron Microscopy Study of Thermal Oxidation of Single Crystalline Aluminum Nitride

2006 ◽  
Vol 955 ◽  
Author(s):  
Jharna Chaudhuri ◽  
Rac Gyu Lee ◽  
Luke Owuor Nyakiti ◽  
Zheng Gu ◽  
James H Edgar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Amorphous Oxide ◽  
Oxide Layers ◽  
Transmission Electron ◽  
The Impact

ABSTRACTThe impact of process conditions and crystal properties on the structure of thermal oxides formed on AlN were determined by high resolution transmission electron microscopy (HRTEM). Oxidation for 2 hours at both 800 ° and 1000 °C produced mostly amorphous oxide layers whereas oxidation for 4 and 6 hours at 1000 °C produced partly crystalline and epitaxial oxide layers. The crystalline oxide was mostly single phase á-Al2O3 except at the surface where it was a mixture of γ-Al2O3 and á-Al2O3. The amorphous oxide layer first transformed to γ-Al2O3 and then to the stable á-Al2O3 as evidenced by the non-uniform thickness of the oxide and the existence of the γ-Al2O3 at the surface. The AlN crystal contained a high density of defects at the interface at 800 °C but it was nearly defect- and oxygen-free at 1000 °C. This could be due to the rapid diffusion of the nitrogen and aluminum interstitials at high temperatures leading to a point defect equilibrium throughout the nitride. A faceted interface between Al2O3 and AlN could be attributed to non-uniform out diffusion of aluminum.

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