bluuebunny/crossref_metadata_2025 huggingface dataset:
Defect and Microstructural Analyses in Ferromagnetic Material
Authors: Horton L. L.
Published: March 2011

Transmission electron microscopy (TEM) of ferromagnetic materials requires special and often time-consuming procedures to obtain good images. Tilting and high resolution experiments are particularly difficult. A survey of several investigations of microstructures in ferromagnetic materials ranging from pure iron to commercial magnet materials is presented. The topics of these investigations include determination of Burgers vectors and interstitial/vacancy character for dislocation loops, cavity shape analyses, magnetic domain/microstructure correlations, and characterization of structures resulting from isotropic spinodal decomposition. Problems encountered during these studies as they relate to magnetic materials and the modifications to standard microscope operating procedures required to overcome these problems are presented. This discussion includes specimen requirements, specimen loading and insertion, and alignment corrections required during specimen tilting.
Identification of Growth Induced Planar Defects in Silicon
Authors: Strunk H. P. , Kessler A. , Bauser E.
Published: March 2011

Planar defects have been detected by transmission electron microscopy in silicon epitaxial layers that have been grown from Ga solutions below 500 °C. According to fringe contrast analysis, this defect can be modelled by a plane of Ga atoms within the Si lattice. This plane forms during crystal growth due to local preferential incorporation of Ga atoms at crystallographically defined sites, that occur repetitively in the trains of monomolecular growth steps at the liquid/solid growth interface.
Microstructure of Rapidly Solidified Al-Si Exhibiting Enhanced Superconducting Properties
Authors: Noack M. A. , Drehman A. J. , Pelton A. R.
Published: March 2011

Tsuei and Johnson previously reported significantly enhanced superconducting transition temperatures for rapidly solidified Al-Si alloys. Here we report a microstructural study of melt spun Al80Si20ribbons to determine the mechanism responsible for this enhancement.

Results of this investigation revealed three distinct microstructures from the top surface to the more rapidly cooled bottom surface (which was in contact with the melt-spinning wheel). Near the top, the microstructure is of hypoeutectic morphology even though this is a hypereutectic alloy. The predominant microstructure is cellular. A 1 to 3Wmthick layer at the bottom of the ribbon was found to be responsible for the largest enhancement. This layer is composed of fine-grained supersaturated fcc Al containing densely distributed dc Si precipitates. Microdiffraction analysis revealed a cube/cube orientation relationship between the precipitates and the matrix. These results provide insight into the possible mechanism for the enhancement.
Materials in Sports a New Concept for the Teaching of Materials Science and Engineering
Authors: Ebert Lynn J. , Michal Gary M.
Published: March 2011

Most sports equipment in common use today represents highly developed engineering structures. Many of the equipment items have evolved empirically, but nonetheless can be used to illustrate basic principles of materials engineering, applied mechanics and kinetics. Using the most common items of sports equipment (footballs, tennis racquets, vaulting poles, etc.), a new course has been developed which introduces first year science and engineering students to materials science and engineering, as well as basic engineering, using a medium they can relate to personally—sports. Emphasis is placed upon the factors which make the equipment functional. These factors include both the basic materials from which the equipment is made and its fundamental design. Detailed treatment is given to the origin of the various species of materials. The processing used to produce the full spectrum of properties required of the various equipment items and the important structure-property relations in the equipment's use are presented. “Hands-on” experiments, guest lectures by world authorities in several fields of sporting activities and equipment use demonstrations compliment the lecture-recitations of the course.
The Undergraduate Educational Program for Ceramic Engineering and Glass Science at Alfred University
Authors: Rossington David R.
Published: March 2011

Alfred University is one of only eleven ABET accredited Universities in the U.S. offering Bachelor's degrees in Ceramic Engineering. The New York State College of Ceramics at Alfred University is one of the statutory colleges of the State University of New York system. Funding for the College comes from S.U.N.Y., but the College is an integral part of Alfred University and is administered by the Alfred President and Board of Trustees.
The Metals/Materials Dichtomy: Real or Apparent?
Authors: Bernstein I. M.
Published: March 2011

Some of the reasons for and the developing impact of the rapid broadening of the field of materials are presented and the impact of the concomitant shift away from the domination of metals on education and research is assesed. Both the opportunities presented by this view of the materials spectrum and the inherent dangers of over reaction and hyperbole are presented.
Plastics Engineering Education at the University of Lowell
Authors: Schott Nick R. , Deanin Rudolph D.
Published: March 2011

Uniqueness Of Plastics As Materials Starting with the Hyatt brothers' development of the plastic billiard ball in 1868, the plastics industry has grown exponentially during the present century, until it now occupies more than 5% of the industrial work force. The rapidly growing importance of plastic materials is a result of the many unique qualities they offer, which distinguish them from conventional structural materials such as metals, ceramics, wood, leather, textiles, and paper. Among these unique qualities are generally easy processability, light weight, wide range from rigidity to flexibility, toughness, wide range from adhesion to lubricity, abrasion resistance, wide useful temperature range, grades with high resistance to burning, electrical and thermal insulation, electrical conductivity when desired, wide range of color and appearance from highly transparent to completely opaque, weather resistance, chemical resistance to most inorganics and many organics, and often low to moderate cost.
Pedagogical Theories and Strategies in Education for Materials Research: A Hierarchical Approach
Authors: Roy Rustum
Published: March 2011

The topic of education optimized for materials research is treated In sequence at four hierarchical levels starting with the most general.

Materials Research is the earliest and best developed example within the physical sciences and engineering of an integrative field (discipline?). Yet very little thought and no research (including the relevant cognitive science) has addressed the subject of how best one can educate a cadre of materials researchers. The author will adduce Inductive and anecdotal data to point some fruitful directions in reorganizing the approach to education in integrative knowledge fields.

The first important thesis of this paper is that we have failed to analyze correctly the appropriate hierarchical relationships among individual scientific disciplines, engineering departments, and technological research groupings.

The second major point is that education for materials research is done is several departments (materials science, physics, electrical engineering, chemical engineering, etc.) and Indeed that some mix of disciplinary roots is desirable for the materials research cadre. Improvements will be proposed in four areas: (1) Optimum content of MSE curriculum, (2) the widespread introduction of MSE minors, (3) under-representation of electronic materials, pol ymers, ceramics.

The third aspect deals with the modularization of the content and teaching materials to allow adaptation to local needs in a field like materials research. The international materials community has done rather well by establishing the Materials Education Council and the Journal of Materials Education, for producing and disseminating print media. The status and usage of JME will be described.
Approaches to an Integrated Undergraduate Education in Materials Science and Engineering
Authors: Flemings Merton C. , Sadoway Donald R.
Published: March 2011

This is an era of great excitement and opportunity in the materials field, particularly for those of us in universities. Our field has expanded greatly in recent years. Materials scientists and engineers have joined forces with physicists, chemists, electrical engineers and others to pave the way for major technological advances. Remarkable strides in instrumentation have brought insights unimagined a decade ago. The realization is growing in so many other fields of research and education that further advances are limited largely by the capabilities of materials. There is no field of engineering that could not improve the efficiency or performance of its products, if better materials were available.
Ceramic Engineering Education
Authors: Readey D. W.
Published: March 2011

Ceramic Engineering or Ceramics has existed as a separate academic discipline in the United States for over ninety years having been founded to ensure the application of the principles of chemistry to the fabrication of ceramic products. With the maturation of the traditional ceramic industries, including refractories and glass, and the growth markets of high technology ceramics for electronic and structural applications, the requirements of a ceramic engineering education are undergoing rapid change. The current status of the ceramic industry and its impact on education and the ceramic education infrastructure are reviewed. Within this framework and the property and structure emphasis unique to ceramics, a model undergraduate degree curriculum is presented.
“University–Industry Interactions – Education For Entrepreneurship
Authors: Harwood J. J. , Baba M. L.
Published: March 2011

Two phenomena are converging on the American technological scene which offer challenging implications and opportunities to engineering education. The first relates to the impacts of the wave of small, entrepreneurial companies emerging on the American industrial scene. The second relates to recent developments in university structure and policy innovations to promote university/industry linkages and regional economic growth. Entrepreneurship is encroaching into academic life and policies and could well become a dynamic feature of the university world and its technology transfer activities.
Materials Science in the Electrical Engineering Curriculum
Authors: Cochran David R.
Published: March 2011

Materials properties are crucial to the operation of electron devices. Based on this fact, the inclusion of the study of material science as an integral part of an electrical engineering curriculum is examined. The trends in the curriculum over a period of time are considered with respect to the growth of technology. A nationwide sampling of the electrical engineering curriculum over ten year periods is cataloged. Tabulated results are presented. Based on these results, a view of future curriculum that incorporates material aspects is presented.
Electronics Materials and Devices
Authors: Wood John
Published: March 2011

The Open University was founded in 1969 with the aim of providing educational opportunities for adults who wish to study at home or work in their own time. Like all universities in the United Kingdom it is funded mainly from central government finance supplemented by student fees. It has the right to grant degrees at undergraduate and postgraduate level. In common with all other UK universities it employs external assessors and examiners from other higher learning institutions in order to maintian standards and to ensure equivalence of qualification throughout the country. In addition, the university offers a wide range of other educational material such as single courses at degree level, specialist short courses on scientific/technological updating, general community education etc. About 120,000 people are registered (1985) as students of which approximately two thirds are engaged in obtaining an undergraduate degree. The university is ‘Open’ in that it does not insist on any formal entry qualifications and accepts students on the basis of a ‘first come first served’ principle. Approximately 50,000 applications are received each year and the number finally accepted is about 18,000. This number is determined by the grant in aid from central government. Although the nature of the student body changes with time, there tends to be a 55:45 ratio of male to females.
Energy Distribution of Ions in Plasma Etching Reactors
Authors: Briaud P. , Turban G. , Grolleau B.
Published: March 2011

The energy distributions of the positive ions bombarding the ground electrode in a parallel plate plasma etcher have been measured by means of an electrostatic analyzer after extraction through a 50 μm orifice.Three gases were studied; Ar, CF4 and SF6, with pressures varying from 5 mtorr to 200 mtorr as a function of the discharge frequency.In the low frequency regime (25–125 kHz) the maximum energy of the ions is close to the applied potential (i.e., 500–600 eV).A secondary ion peak is observed and attributed to the secondary electron ionization.SF6 plasma exhibits a behaviour different to that of Ar and CF4 plasmas because of the high electron attachment of the molecule.
OES, LIF, and MS Studies of Silane, Disilane, and Chlorosilane Plasmas
Authors: Lee H. U. , Ross R. C. , De Neufville J. P.
Published: March 2011

Using optical emission spectroscopy (OES), mass spectrometry (MS), and laser-induced fluorescence (LIF), we are investigating a number of glow-discharge reactions as a function of RF power, flow rates, partial pressures, and H2 dilution under realistic thin-film deposition conditions.In this paper we report on the preliminary results of two studies:

1)

The formation of radical and polymeric species in SiH4 and Si2H6 plasmas, and

2)

The characterization of SiF4 + H2 plasmas and the detection of HSiCl and HSiF in the plasmas of SiH2Cl2 and SiH2F2, respectively.
A Mechanistic Study of CC12F2/02 RIE for Bipolar Trench Isolation
Authors: Danner David A. , Petrillo Edward J. , Polcari Michael R.
Published: March 2011

The etching of 1.25×3.5 micron trenches in silicon for use in bipolar device isolation using chemistries based on CC12F2 (freon-12) and 02 has been investigated.It was found that competitive reactions in the trench favor deposition of a Si02-like material on the sidewalls and promote lateral etching of the N+ subcollector under conditions necessary for high selectivity.In addition thermally activated processes were investigated by direct measurement of the sample surface temperature during etching.The temperature threshold for the initiation of subcollector undercut was determined to be 70C and the vertical etch rate exhibited an inverse activation indicating adsorption-limited etching.Results are discussed in the context of a qualitative model, based on the etchant-unsaturate model, which describes the contribution of several phenomena to the trench shape.These include sidewall passivation, species transport, deposition, N+ doping enhancement, Si loading, and ion scattering.
Amorphous Hydrogenated Semiconductors
Authors: Reimer Jeffrey A.
Published: March 2011

Semiconducting thin films are produced in plasma and CVD reactors and are commercially useful materials because of a ubiquitous presence of hydrogen, a low density of defects, and electro-optical properties which vary systematically with composition.However, little is known about how variations in fundamental growth parameters produce concomitant changes in film properties, particularly hydrogen incorporation.The reason for this gap in knowledge derives partly from the lack of adequate structural probes of disordered materials.In recent years nuclear magnetic resonance spectroscopy (NMR) has emerged as a powerful probe of the microstructure of amorphous semiconductors.I will discuss recent developments in the application of NMR to studies of amorphous hydrogenated semiconductors, and interpret these results in terms of the chemistry and physics of the growth process.
Optical and Electrical Properties of Hydrogenated Amorphous Silicon Nitride Films Deposited in Various PECVD systems
Authors: Voke Nancy , Kanicki Jerzy
Published: March 2011

Hydrogenated amorphous silicon nitride films, prepared in various commercially available plasma enhanced chemical vapor deposition systems, have been investigated in terms of different deposition conditions.The full characterization of these gate insulators has been carried out by different techniques.Experimental data and interesting findings obtained from this study are presented.Special attention has been devoted to the influence of hydrogen on optical and electrical properties.
Hydrogenated Amorphous Carbon(a-C:H), An Overview.
Authors: Meyerson Bernard S.
Published: March 2011

Over the past several years, numerous new materials have been prepared by the glow discharge decomposition of gaseous species.Among these, a material with extraordinary though as yet unfulfilled potential is hydrogenated amorphous carbon(a-C:H).As a metastable state between the two naturally occurring carbons, graphite and diamond, a-C:H can display a wide range of phyical characteristics.Film optical and electronic properties are a strong function of deposition parameters, where 2.l>Eopt >0.9eV.and 1016 >ρ>106Ω-cm., for films deposited between 75 and 375C.Occasionally referred to as “diamond-like”, such films can be extraordinarily hard and virtually impervious to chemical attack.The interrelation of film structure on the atomic level and macroscopic film properties will be discussed, with emphasis on the current controversy over whether such material is indeed diamond-like in its microscopic ordering.
Plasma Mode Trench Etching with Direct Hydrocarbon Injection
Authors: Leeke Steven D. , Liu David Kuan Yu , McVittie James P.
Published: March 2011

Planar plasma etching of silicon for fabrication of deep trenches has been studied using the method of factorial design.A highly anisotropic etching profile with a slight positive slope is obtained using SF6, C2C1F5, and CH4 in the low energy plasma etch mode.The anisotropy is attributed to the polymerization of CH4 molecules with the active species in the plasma.The polymer is removed preferentially in the vertical direction by energetic ions from the plasma, leaving the polymer layer on the side wall to inhibit lateral etching of silicon.Good uniformity across the wafer and smooth trench surfaces are obtained with this process.Trench depths of greater than 3μm with less than 0.24μm of undercut are observed.Etch rate measurements were made and found to be greater than 1000 angstroms/minute.Selectivity over the oxide mask is greater than 15:1.

By using factorial design to statistically characterize this process, the effects of interactions between various process parameters are studied.Optimal etching conditions are obtained from the interaction terms for the process parameters.The ability to etch deep trenches with smooth surfaces, low damage, low linewidth degredation, and high selectivity make this process useful for many applications in VLSI devices.
Optical and Compositional Properties of a-C:H and BN Films
Authors: Pouch John J. , Alterovitz Samuel A. , Warner Joseph D.
Published: March 2011

The amorphous dielectrics a-C:H and BN were deposited on III–V semiconductors.Optical band gaps as high as 3 eV were measured for a-C:H generated by C4 H10 plasmas; a comparison was made with bad gaps obtained from films prepared by CH4 glow discharges.The ion beam deposited BN films exhibited amorphous behavior with band gaps on the order of 5 eV.

Film compositions were studied by Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS).The optical properties were characterized by ellipsometry, UV/VIS absorptiofr, and IR reflection and transmission.Etching rates of a-C:H subjected to O2 discharges were determined.
Monte Carlo Modeling of Ion Transport Througe RF Glow Discharge Sheaths
Authors: Fisher Donald A. , Thompson Brian E. , Sawin Herbert H.
Published: March 2011

The transport of ions through a rf-plasma sheath was simulated using a Monte Carlo method to determine the distribution of ion bombardment energy and impingement angle.Several types of ion-molecule interactions were tested to determine their effect on the distributions: elastic hard-sphere scattering, elastic potential-field interactions (based upon reported literature values obtained by drift tube measures), and charge transfer.The type of elastic scattering does not significantly change the angular distributions; however, the scattering cross-sections changes as a function of ion energy (or sheath E/P) for the potential-field interactions.The fraction of collisions giving charge exchange makes a large difference in the simulated directionality as well as a factor of two difference in the average bombardment energy.
RIE Plasma and ETCH Mechanisms
Authors: Keller John H.
Published: March 2011

Three independent models are presented: One for determining the plasma density and target sheath voltage, one for silicon etching using CF4plus O2, and one for RIE etching of silicon dioxide.

In most dry etching techniques the target and plasma voltages play a large role.In this paper, the dc and rf mechanisms which determine the plasma density, and thus the target voltage, are presented.The mechanisms used are: 1) secondary electron ionization in the sheath, 2) secondary electron ionization in the plasma, 3) ionization by tertiary electrons, 4) I2R heating of the plasma electrons, and 5) sheath heating of plasma electrons.An equivalent circuit for an rf discharge is presented, and the relationship between the plasma voltage and target sheath voltage are discussed.

The mechanisms used to model silicon etching include chemical etching, ion enhanced etching and diffusion of reactive species.Laser induced fluorescence data from G.S.Selwyn will be discussed.These data show spatial resolution of a reactive species in an RIE plasma and show the diffusion effects.

The ion-enhanced etching effect for SiO2, shows a much stronger voltage dependence than that for Si, which is almost independent of voltage.Data from G.Fortuno show that the voltage dependence for SiO2 is similar to that of sputtering.The mechanisms used to model SiO2 etching include the work by G.Fortuno (1985) and that by B.N.Chapman and V.J.Minkiewicz (1978).
A Plasma Chemistry and Surface Model for the Deposition of a–Si:H from RF Glow Discharges: A Study of Hydrogen Content
Authors: Kushner Mark J.
Published: March 2011

An integrated electron kinetics, plasma chemistry, and surface deposition model has been developed to study the relationship between film characteristics and plasma parameters in the plasma enhanced chemical vapor deposition (PECVD) of amorphous hydrogenated silicon (a–Si:H) in low pressure parallel plate RF discharges.The integrated model consists of a Monte-Carlo simulation for the electron distribution function in the RF discharge, a time and spatially dependent plasma chemistry model, and a model for the surface deposition process.The surface model consists of an accounting of the surface density of adsorbed species, and the fractional distribution of various types of bonds (e.g.Si–Si, Si–H, Si–.) in the film.The calculated distribution of radicals in silane discharges will first be discussed.The computed hydrogen content and deposition rates of a-Si:H films from silane and disilane discharges are next discussed and compared to experiment.The dependence of hydrogen content on Rf power and substrate temperature is calculated and agrees well with experiment.Mechanisms are proposed to explain these dependencies.
Deposition of Dielectric Films by Remote Plasma Enhanced CVD
Authors: Lucovsky G. , Tsu D. V. , Markunas R. J.
Published: March 2011

We describe a plasma enhanced chemical vapor deposition process (PECVD) developed for the low temperature deposition of thin films of silicon oxides, nitrides and oxynitrides.The process, designated as remote PECVD (RPECVD), differs from conventional PECVD in two ways; (a) not all of the process gases are subjected to plasma excitation; and (b) the deposition is done outside of the plasma region.We include an empirical model of the deposition process chemistry and discuss the use of infrared spectroscopy (IR) and Auger electron spectroscopy (AES) to characterize the local atomic structure of the deposited films.
Deposition of Titanilum Nitride Thin Films by Plasma Enhanced CVD and Reactive Sputtering
Authors: Gleason E. F. , Hess D. W.
Published: March 2011

Titanium nitride films were deposited from TiCl4 /NH3 mixtures in a rf glow discharge.The deposition was carried o t at pressures between 0.1 and 0.7 Torr, RF powers of 0.1 to 1.1 watt/cm2, and temperatures between 400°C and 600°C.The films deposited at 600°C had low chlorine content and resistivities in the range of 100 to 200 μΩ-cm.Films deposited at temperatures below 500°C contained large amounts of chlorine (> 15 at %) and showed poor electrical properties.The films were further characterized by Rutherford Backscattering Spectroscopy (RBS), X-ray Photoelectron Spectroscopy (XPS), and Auger Electron Spectroscopy (AES).The effect of plasma parameters on the deposition rate and film properties is discussed.Comparisons to films prepared by reactive sputtering of titanium in a nitrogen atmosphere are presented.
Deposition of Aluminum Nitride Films Using RF Reactive Sputtering
Authors: Kumar N. , Pourrezaei K. , De Maria R. J. , Singh B.
Published: March 2011

RF reactive sputtering of aluminum in argon-nitrogen mixture has been used to deposit basal oriented aluminum nitride films at temperatures lower than 200°C.X-ray diffraction studies of films deposited in 40–60% nitrogen show very high degree of crystallinity.A characteristic step-like decrease in target induced dc bias and the deposition rate (at a constant rf power level) is observed when the nitrogen content is increased above about 20%.The plot of target bias vs.nitrogen content shows a typical hysteresis loop which decreases in size at higher power levels, thus indicating nitride formation at the target surface.Glow discharge mass spectrometry was used to monitor the ions arriving at the substrate.There is a dramatic decrease in Al+ ion current when the nitrogen percentage in the gas mixture is increased above 20%.
Etching and Surface Modification of Polyimide in O2 -SF6 Plasmas
Authors: Kogoma M. , Turban G.
Published: March 2011

Etch rates of Kapton H polyimide film in SF6 - O2 plasmas (0.25 torr) were studied as a function of the input gas mixture, the excitation frequency (25 kHz -450 kHz; 13.56 MHz) and the biasing mode.The treated surface was examined by X P S, SEM and contact angle measurement.

The ion and neutral species of the plasma were sampled and analyzed by mass spectrometry.A proposed kinetic analysis of the etching mechanism is in good agreement with the experimental data.
Quartz Crystal Microbalance Studies of the Plasma-Assisted Etching of Polyimide and Tungsten Thin Films
Authors: Fracassi F. , Coburn J. W.
Published: March 2011

The etching of polyimide thin films and tungsten thin films has been studied as a function of bias voltage using two quartz crystal microbalances (QCM) installed in a low pressure 13.56 MHz rf plasma system.One of the QCM's is biased (rf bias was used for the polyimide films; de bias was used for the tungsten films) and the other QCM is unbiased.In this way, the influence of energetic positive ion bombardment on etching can be studied.The etching of polyimide is studied in CF4-O2 glow discharges whereas CF4-H2 gas mixtures were used in the etching of tungsten.In the tungsten etching studies, the surfaces were vacuum-transferred to an Auger electron spectrometer for surface analysis.
Thermal and Ion-Assisted Reactions of Al0.3Ga0.7as with Molecular Chlorine
Authors: Balooch M. , Olander D. R. , Siekhaus W. J.
Published: March 2011

Reaction of Al0 3Ga0 7As with molecular chlorine was studied with and without simultaneous bombardment by energetic argon ions.The reaction products signals were measured as functions of surface temperature.For the purely thermal reactions, the main products below 600 K were AlCl3, AsCl3 and GaCl3.The etching rates were two orders of magnitude lower than those of pure GaAs.With simultaneous ion bombardment, the reaction product signal of AsCl3 at room temperature increased by almost a factor of four over the corresponding thermal reaction signal.The comparable enhancement factor for pure GaAs was ∼6.
Dynamics of Electron and Photon Stimulated Desorption
Authors: Walkup R. E. , Avouris Ph.
Published: March 2011

We discuss specific examples of desorption due to electron or photon bombardment of solids, in which the repulsive interactions that result in particle expulsion can be clearly identified.A particularly interesting example is the desorption of positive ions from alkali-halides.Classical trajectory calculations are used to provide a picture of the atomic-scale motion during desorption.The results show that dynamic distortions of the lattice play a crucial role in the desorption process.
The Interaction of CF3+ and CH4+ With SiO2 Surfaces
Authors: Thomson D. J. , Helms C. R.
Published: March 2011

In this paper we present experimental results and a theoretical model for the interaction of CF3+ and CH4+ with SiO2 surfaces.A comparision of the sputter rates for CF3+ and CH4+ with a molecular sputtering model shows that there is a chemical enhacment in the etch rate for CF3+ but not for CH4+.By comparing the Si (LVV) AES spectra for these two surfaces we have determined that the enhancement is due to the strong Si-F bond promoting the formation of volatile carbon containing compounds.
Magnetron Enhanced Reactive Ion Etching in a Hexode System
Authors: Bell Scott , Bril Thijs
Published: March 2011

A method of forming a uniform magnetic field in a modified hexode type etch system is described.Experimental results of etching Si, SiO2 and photoresist with NF3 are presented.The magnetic field effectively increases the ion flux and decreases the energy of the ions bombarding the cathode.It was found that adding a magnetic field increases the etchrate of Si for the conditions studied, but for SiO2 and photoresist, the decreased ion bombardment energy leads to lower etchrates under certain conditions.The resulting effect on selectivities is discussed.
Anisotropic Dry Etching of Aluminum Films Deposited on Topographic Steps
Authors: Maa Jer-Shen , Halon Bernard
Published: March 2011

During the etching of aluminum film, if the film is deposited on a surface which contains sharp topological steps, and if the etching proceeds mainly along the vertical direction, it becomes very difficult to remove the remaining residue.Experimental results are discussed in terms of effects of native oxide film and polymer film formation.A simple model is proposed to reveal the residue formation process and to explain the problem encountered during the removal of the etched residue.
Plasma Assisted Oxidation of Si at Temperatures below 800°C
Authors: Williams C. K. , Reismanu A.
Published: March 2011

A system for plasma assisted oxidation of Si at temperatures below 800°C is described.Oxides grown in this system have an unusual thickness versus time relationship.The first 110 nm of oxide exhibit a t1/2 dependence.Any additional growth shows a t1/3 dependence.Pressure, oxygen concentration, and rf power are all important parameters in determining the growth rate and uniformity of the oxide layers.Breakdown measurements on these oxide layers show that post oxidation annealing is necessary if these oxides are to compete with thermal oxides.The type of annealing is very important in determining the breakdown voltage.The results of various annealing procedures are described.The effects of heating the wafers independent of the heat generated by the plasma, and the frequency dependence of the growth are discussed.
RF and Microwave Plasma Deposition of Polymer Films: Effect of Frequency
Authors: Claude R. , Moisan M. , Wertheimer M. R.
Published: March 2011

The surface wave (SW) plasma technology is used to investigate possible frequency effects in the deposition kinetics of plasma polymers over the range 100–915 MHz.Hydrocarbon and fluorocarbon monomers are excited by a SW produced argon plasma, at a total pressure of 50 mTorr, under various monomer flows.Using Yasuda's normalization procedure, we have so far been unable to distinguish frequency dependent deposition in this high frequency (HF) regime.However, the present data indicate substantially (an order of magnitude) higher deposition rates than those reported by Gazicki and Yasuda for low frequencies.
Optical Diagnostic Studies in Plasmas and Plasma Processing
Authors: Donnelly V. M.
Published: March 2011

Optical diagnostic probes have greatly increased our understanding of low pressure discharges used in etching and deposition processes for microelectronics fabrication.Optical emission induced by energetic electron impact excitation provides a qualitative determination of concentrations of a number of important atoms and small radicals.Rare-gas actinometry, combined with high resolution line-shape measurements can convert emission data into quantitative relative number densities, and provide information on mechanism of excited state formation.Emission from products of etching reactions gives insights into mechanisms and serves as an end-point indicator for many commercial processes.Laser induced fluorescence is a sensitive probe which is most useful for small radicals.Quantitative, relative ground-state number densities, internal energy distributions, translational energies and electric fields can be determined by this technique.When optical emission or laser induced fluorescence measurements are performed with spatial resolution and in-phase with respect to the applied field, additional insights are obtained on the dynamics of the discharge processes.Finally, infrared and visible-ultraviolet absorption spectroscopy can be used to measure absolute number densities.This technique also can provide spatial and temporal resolution.

This paper reviews and compares the various optical techniques used in plasma diagnostics with particular emphasis on studies of low pressure radio frequency discharges used in etching and deposition of thin films.
Crystallization Behavior and Properties of Rapidly Solidified Ni-Mo-B Alloys
Authors: Wan C.C.
Published: March 2011

The crystallization phenomena of certain ternary glass Ni-Mo-B alloys and their consolidated bulk properties, including age hardening effects after proper heat treatment, are investigated. Within the composition range studied, the glassy alloys crystallize by a two-stage process - first by forming a metastable microcrystalline structure of Ni solid solution at temperature around 490–530°C followed by boride precipitation at temperatures around 700–770°C. The boride, which is identified by x-ray diffraction as Mo2NiB2 , grows to submicron size after the alloys have been thermally treated at 1000°C and above for certain periods of time. Microstructural analysis shows borides isolated and well dispersed in Ni-Mo alloy matrix. Age hardening is achieved by precipitating the Ni/Mo intermetallic compound(s) in Ni-Mo matrix at an intermediate temperature of previously solutionized samples. Another characteristic of this group of alloys is the relatively high eutectic temperature, i.e. 1230°C and above. This will allow the alloys to be hot consolidated to full density by certain commercially available processes, such as hot isostatic pressing (HIP), while still maintaining the unique microstructure inherited from rapid solidification process. Hardness, hot hardness and hot tensile properties of some consolidated alloys are discussed.
Microstructural and Chemical Components of Ceramic-Metal Interfacial Fracture Energies
Authors: Cannon R. M. , Jayaram V. , Dalgleish B. J. , Fisher R. M.
Published: March 2011

Failure of ceramic-metal interfaces induced by residual or applied stress is often brittle in nature although plastic strain in one or more bonding layers may add to the fracture energy for decohesion. Thus, the fracture toughness depends on chemical bonding across the interface, the plasticity and flow stress of the metal as well as other factors, arising from local internal stresses and the microstructure of the ceramic-metal couple, that cause crack tip branching, deflection, bridging, blunting or shielding. Electron microscopy and DCB testing of metal-glass systems provide insights into the relative importance of factors that determine the decohesion resistance.
Stresses in Adhesively Bonded Bi-Material Assemblies Used in Electronic Packaging
Authors: Suhir E.
Published: March 2011

The magnitude and the distribution of stresses in elongated adhesively bonded bi-material assemblies subjected to uniform heating or cooling are determined and discussed. The suggested approach enables one to evaluate the stresses in the assembly components themselves, as well as the shearing and normal (peeling) stresses in the interface, with consideration of the attachment compliance. The case of an epoxy bonded assembly is used to illustrate the developed theory.
Microstructural Observations and Mechanical Behavior of Pb-Sn Solder on Copper Plates
Authors: Frear Darrel , Grivas Dennis , Quan Lenora , Morris J. W.
Published: March 2011

The microstructure and mechanical properties of Pb-Sn solder joining Cu plates were studied. Yticrostructural observations were made on both the bulk Pb-Sn solder and on the interface between the solder and Cu plates. Pb-Sn solder has a two-phase microstructure in which the Pb-rich phase is the weaker. β-Sn precipitates in the Pb-rich phase were characterized in TEM. Intermetallic phases (Cu6Sn5and Cu3Sn) that form during the reaction of molten Pb-Sn solder with Cu were investigated. Solder joints were tested to fracture in both shear and tensile configurations. The mechanical properties and fracture surface characteristics are reported.
Impurities of Epoxy Novolac Resins and their Influence on the Reliability of Encapsulated Semiconductors.
Authors: Kanagawa Shuichi , Terada Yutaka
Published: March 2011

Impurities, especially chemically bonded impurities, of o-cresol novolac epoxy resins and their influence on the moisture resistance and other properties of the epoxy molding compounds have been investigated to clarify the influence of impurities of epoxy resins on the reliability of encapsulated semiconductor. As a result, the existence of hydrolyzable chlorine and hydroxyl group-containing impurities has been confirmed, and it was found that the impurity such as a hydrolyzable chlorine causes undesirable influence on both the moisture resistance and electrical properties at high temperatures. It was also found that the impurity such as a hydroxyl group causes undesirable influence on the moisture resistance, and that the lower hydroxyl content gives the higher heat resistance as a result of an increase in the epoxy content.
Solvent Induced Crack-Like Defects in Adhered Polyimide Films
Authors: Yang A. C. M. , Brown H. R.
Published: March 2011

When thin adhered films of a polyimide (Ciba-Geigy XU-293) on rigid substrates are immersed in xylene, defects, that look like cracks to the naked eye, are formed. These defects are caused by the presence of the combination of the equibiaxial tension in the film and the xylene. The stress comes from the solvent loss and the thermal expansion mismatch between the substrate and the film. The defects are found to be local deformation zones, showing considerable optical anisotropy and a microstructure strongly influenced by the adhesion condition to the substrate. Although they retain a smooth surface on the face in contact with the substrate in the bonded regions, the deformation zones release a significant amount of stress. The stress released is measured by a photoelastic technique and is found to be in excellent agreement with that calculated from the local thickness change assuming simple elasticity. These deformation zones grow at a speed that is independent of their length and initiation time but increase rapidly with film thickness from a threshold at a thickness of about 3 microns. The observed thickness effect can be explained by a fracture mechanics analysis of adhered films where, unlike the case in free films, the energy release rate, G, is independent of crack length but varies with film stress and linearly with film thickness.
Predictive Design of Multicomponent Polymers for Printed Circuit Boards
Authors: Beuhler A. J. , Wrezel J. A. , Maas J. L. , Sundahl R. C.
Published: March 2011

The most common structural and dielectric materials for printed wiring boards are polymer composites such as epoxy/fiberglass and polyimide/fiberglass. The light weight, low cost, processability, and low dielectric constant of these materials make them particularly suited for this application.
Fluorination of Polymeric Films by a Non Equilibrium Plasma at an Atmospheric Pressure
Authors: Rouzbehi F. , Amouroux J. , Goldman M.
Published: March 2011

The polymerization of I-I difluoroethylene has been realized by a non equilibrium plasma at an atmospheric pressure on polymeric substrates such as polypropylene (PP). The graft copolymerizat ion onto the PP film was carried out when activating the polymeric substrate in the presence of argon. The structure of the polymeric film obtained depends on the residual oxygen in the plasma reactor. The role of the radicals which interfere in the grafting mechanisms of monomers onto polypropylene films has been studied.
Laser Photoetching of Polymers
Authors: Cole H. S. , Liu Y. S. , Philipp H. R. , Guida R.
Published: March 2011

Laser photoetching of polymers has been shown to be a useful method of producing via holes or patterns and is of potential importance in microelectronics fabrication. The maskless, self-developing nature of the process also offers unique opportunities in the preparation of packaging assemblies. Etching of via holes at any discretionary site for multichip interconnect, for example, provides the circuit designer with additional design flexibility. The photoetching rate is dependent on the absorption coefficient of the polymer (at the laser wavelength) and the irradiating fluence. Further, there appears to be an optimum absorption coefficient to achieve the maximum photoetch rate for a given fluence level. To laser drill holes for interconnects, it is desirable to irradiate at the highest energy (increased rate) possible without damaging underlying metal contact pads.
Metal Atom Reactions with Polymer Films
Authors: Kovac Caroline A. , Jordan Jean L. , Pollak Roger A.
Published: March 2011

The chemical nature of the interface formed when an electropositive metal (chromium) is evaporated on the surface of oxygen-containing polymers has been investigated by synchrotron-radiation excited photoemission spectroscopy and by near-edge X-ray absorption fine stnrcture spectroscopy (NEXAFS). PMDA-ODA polyimide was studied along with two polymers intended to more simply model the complex chemical functionality of polyimide. Core-level spectra were resolved into distinct peaks, which were assigned to specific atoms in the polymer units, and changes in the spectra were monitored as chromium metal atoms were evaporated onto the surface. Similarly, NEXAFS spectra were taken as a function of chromium deposition. Results of these experiments show that chromium initially reacts very rapidly with surface carbonyl groups, but less strongly with ether oxygens or arene rings. In all polymers studied, formation of an electron-rich, carbide-like species was observed.
Interconnection Trends and Impact on Materials
Authors: Knausenberger W. H. , Pinnel M. R.
Published: March 2011

Rapid technological advances in electronic systems technologies are placing increasingly severe demands on interconnection media. One primary driving force is the evolutionary advance in the scale of integration in silicon with its inherent cost and performance advantages. A second key driving force is the revolutionary development of photonics which is rapidly integrating into most levels of the interconnection heirarchy. The performance of large scale electronic systems will be increasingly dominated and limited by their interconnection environment. To sustain the present rate of growth in the performance of future systems, new technology directions in interconnection will be necessary.

This paper will explore the traditional levels of interconnection from IC chip packages to the frame level. It will be shown how the various levels of interconnection interrelate and how all levels must be improved simultaneously to achieve the full performance and cost benefits offered by device advances and photonics. The first major step in this evolution is well underway with the rapid transition to surface mounting of devices. This places new demands on materials and assembly technologies which will be discussed. However, the demands of this first step may eventually appear to be minor compared to those yet to come if current trends continue. Several scenarios for this future will be considered and related to the challenges placed on interconnection technology hardware and materials in terms of performance characteristics such as density, speed and heat dissipation.
Metal-Metal Interactions of Importance to Electronic Packaging
Authors: Chang Chin-An
Published: March 2011

Metal-metal interactions have been of vital importance to various technologies, including packaging of electronic materials. Extensive interdiffusion and outdiffusion can lead to undesired alloy formation, and oxide formation on the surface which can hinder subsequent bonding processes. Furthermore, the interactions can be profoundly affected by the ambient gases used, either in the joining process or during subsequent storage and operation. One therefore needs a specially designed metallurgy, a diffusion barrier layer, or a proper ambient to deal with such concerns. The effects of ambient and diffusion barriers on the metal-metal interactions are described. Examples are illustrated where extensive interactions across the diffusion barrier are observed, and their impact on the packaging applications discussed.
Discussion of Wetting Phenomena Under Reducing Atmospheres Using a High Resolution Wetting Balancem
Authors: Jahnke B. , Reiss H.
Published: March 2011

In wetting phenomena surface and interfacial energies play an important part. Due to diffusion, precipitation and adsorption processes these energies are time and temperature dependently changing. The influence on wetting behaviour is investigated using a high resolution wetting balance and metallographic inspection.
Properties of E-Beam Interactive Oxide Films
Authors: Hollenbeck J. L. , Buchanan R. C.
Published: March 2011

Deposition of E-beam interactive films by rf sputtering and their behavior under high intensity irradiation was investigated. Both polycrystalline and amorphous films of SiO2, ZrO2, Al2O3, and Y2O3were deposited and their behavior under irradiation found to-be strongTy dependent on film structure. Using a modified STEM the formation of small holes (<10nm diam.) was achieved with exposure times in the millisecond range. Deposition parameters, film characteristics, drilling behavior, and a possible mechanism are discussed.
Advanced Packaging for High Integration and High Speed Applications
Authors: Hamano Y. , Terasawa M.
Published: March 2011

The rapidly advancing technology which has brought us higher integration and higher speed LSIs has also necessitated the continuous improvement of ceramic packages.