bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrode Potential: A Tool for the Control of Materials and Processes in Electron Device Fabrication: II. EMF Studies of the Behavior of 36 Per Cent Nickel-Iron Alloy in Hydrogen Peroxide — Formic Acid Etchants
Authors: Feder D. O. , Howden W. E. , Huff D. R. , Richards J. W.
Published: September 2009

Mixtures of formic acid, hydrogen peroxide, and water have successfully been used to clean or etch a variety of metals for use in electron device fabrication. Although in most cases the rate of etching is easily controlled, for certain materials, such as the 36 per cent nickel-iron alloy studied, apparently minor variations in either the structure of the material or in the composition of the etchant appear to have a disproportionate effect on the etching rate.

This paper describes the use of electrode potential measurements in predicting the etching behavior of this nickel-iron alloy (invar) and in showing how the etching (and potential) behavior is related to variations in etchant composition and metallurgical state of the alloy.

The results indicate quite clearly the utility of emf techniques both for characterizing subtle changes in bulk metallurgical properties of the alloy and in studying the solution variables which control the etch-cleaning process. In addition, emf measurements are shown to provide a simple, sensitive technique for monitoring and controlling this type of cleaning process.
Gas-Phase Proportional Counting: A Radiotracer Technique for Examination of Electronic Components and Materials
Authors: Stern Herman A.
Published: September 2009

Gas-phase proportional counting, a new radiotracer technique for analysis of gaseous products, has many practical applications in the evaluation of electronic devices and materials. Gas evolution from materials in vacuum tubes can be easily studied, different sources of the same gas can be determined, and traces of organic substances can be detected by converting organics to radioactive gas. This paper discusses the application of this technique to two specific problems: the identification of the source of carbonaceous gases evolved from cathode nickel, and the efficiency of solder flux removal during the manufacture of modular electrical components.
Recommended Practices for Safe Handling of Beryllium Oxide Ceramics
Authors: Ferreira Laurence E.
Published: September 2009

Beryllium oxide ceramics are presently available for use by the electronics industry. The toxic history of beryllium and its compounds has caused great concern in the minds of persons desiring to use them; however the danger can be eliminated when adequate consideration is given to the major problem in the handling of beryllium-containing compounds—that of limiting the concentration of any beryllium compound in the air, measured as beryllium, below the limits prescribed by the Atomic Energy Commission. These limits are: In-Plant: The 8-hr average air beryllium concentration must be kept below 2 μg per cu m. At no time shall the beryllium air concentration be greater than 25 μg per cu m. Out-Plant: The 30-day average of out-plant breathing zone samples shall not exceed 0.01 μg per cu m.

These limits of air contamination can and are being maintained without great cost or difficulty in beryllia processing facilities.

The toxicity of beryllia ceramics is associated with fine particles of beryllia which can be inhaled. Clean, fired beryllia ceramics present no toxic problem.

To handle beryllia ceramics properly the following program is recommended: (1) Develop a medical program, the scope of which is dependent on the nature of the material being processed; (2) set up a clean separate area for handling beryllia that includes the proper protection equipment for processing beryllia ceramics; (3) monitor the air and surface contaminants in the area; and (4) keep a record of the operation.
Beryllium Oxide Dielectric Heat Sinks for Electronic Devices
Authors: Hessinger P. , Strott A. , Haura B.
Published: September 2009

Beryllium oxide is unique among precision ceramic products in that it has a high electrical resistivity and low dielectric loss combined with a thermal conductivity equal to that of aluminum. Because of this advantageous combination of properties, it has found increased use as a dielectric heat sink which can insulate electronic devices electrically, and at the same time remove substantial quantities of heat from them to a chassis heat sink.

High-purity beryllia insulators are produced by ceramic fabrication techniques such as cold-pressing, slip-casting, and extrusion, followed by sintering at temperatures above 1500 C. By the application of precision fabricating techniques, close dimensional tolerances and high surface smoothness can be obtained for maximum compatibility with metal components.

The application of a 0.030 in. beryllia dielectric heat sink beneath a power transistor has, for example, reduced the thermal resistance by a factor of 10 from that obtained when using a thin mica or anodized aluminum insulator. Tests conducted to date have indicated a potential increase of device power operating levels with little or no corresponding increase in junction temperature, or an increased life and reliability for the device by conductive cooling with beryllia.
A 24-Position Semiautomatic Vacuum Tube Exhaust Machine
Authors: Quaglia L. , Byrne J. , Reyling G.
Published: September 2009

As a general rule, it is not economically feasible to purchase complex automatic equipment for the production of vacuum tubes in job lot quantities. However, Varian Associates recently installed to good advantage an exhaust machine incorporating unique specialized features. Among these were the use of getter-ion pumps, a high-temperature (700°C) oven used during a major part of the cycle, and a high degree of electrical process automation. As a result, tube processing is more uniform, the production rate per month has increased significantly, production costs have decreased, and the cost of the equipment can be written off in five years.
Gas Composition During Pumping and in Sealed-off Power Tubes
Authors: Váradi P. F. , Langer H. A. , Saltzman M. N.
Published: September 2009

Gas residues in electron tubes may originate from the tube materials, from gas permeation, and also from vapor picked up from pump environment. A bakeable radiofrequency-type mass spectrometer tube of an ion-gage size was used for measuring the gas composition during the pumping of electron tubes, and also in sealed-off power tubes during their processing and life. It was found that the gas composition in a sealed-off cold tube is extremely different from gas compositions measured during operation of the same tube. These changes are usually reversible. Irreversible changes in the gas environment of the tube may take place during its processing, operation, and also in life. Sudden changes in the gas environment may occur due to changes in operating conditions with respect to filament temperature or electron current of the tube.
Mass Spectrometric Studies of Power Klystron Exhaust Processing
Authors: Noble Lowell , Waits Robert K.
Published: September 2009

The partial pressures of the residual gases present during vacuum processing and operation of power klystrons were measured using a bakeable Diatron-20 mass analyzer tube. The gases present during bakeout at 500 C were, in decreasing abundance, hydrogen, water, carbon monoxide, carbon dioxide, and methane. Carbon dioxide, methane, and carbon monoxide predominated during the conversion of both oxide and nickel-matrix cathodes. Carbon monoxide was evolved when the tube body was bombarded by the electron beam. After seal-off, the residual gas pressure in the klystron was about 5 x 10-7 Torr, consisting of carbon monoxide, methane, and hydrogen. One hundred hours of operation reduced the pressure to 4 x 10-9 Torr. The remaining gases were carbon monoxide and hydrogen.
Quality Control of Getters
Authors: Della Porta P. , Airoldi E.
Published: September 2009

The getter is probably the only part in an electron tube which in most cases is bought from specialized firms and not produced by the manufacturers of electron tubes. Often the tube manufacturers use the getter without checking its properties, and know very little about its behavior and characteristics. For this reason a description of the various problems involved in getter quality control may be of interest.
Influence of Sharp Notches on the Stress-Rupture Characteristics of Several Heat-Resisting Alloys
Authors: Brown W. F. , Jones M. H. , Newman D. P.
Published: September 2009

Stress-rupture tests were carried out on a number of low-alloy steels, ferritic stainless steels and austenitic alloys. Both unnotched and sharply notched bars were tested at various temperatures. The ductilities were determined for both the unnotched and notched specimens.

It was found that all alloys tested were subject to notch weakening. The time and temperature range of this weakening effect and its magnitude varied greatly with the alloy composition. Tests carried out at 900, 1000, 1100, and 1200 F on a low alloy chromium-molybdenum-vanadium steel indicated the notch sensitivity to be time-temperature dependent. The general trends of the data conform to the conception that a precipitation reaction is responsible for the notch sensitivity.

No definite conclusions regarding notch-rupture sensitivity can be made by an examination of the data for the unnotched bars except possibly when this quantity is extremely low. The notch apparently can reduce the ductility of an otherwise ductile metal to the point where there is insufficient plastic flow to eliminate the initial stress concentration.
Effect of a Notch and of Hardness on the Rupture Strength of “Discaloy”
Authors: Hull F. C. , Hann E. K. , Scott H.
Published: September 2009

Certain critical components of jet engines and gas turbines, such as the turbine rotor, require materials of low notch sensitivity at service temperatures around 1200 F. In an Fe-Ni-Cr-Mo-Ti austenitic alloy of attractive basic properties, the effects of hardness as varied by the hardener, titanium, have been related to the behavior of the material in the presence of a notch. Creep-rupture and notched bar rupture tests were conducted at 1000 and 1200 F. The plain bar rupture strength reached a maximum at a hardener content producing 2 per cent rupture strain, and the notched bar strength exceeded the plain bar strength in material in which the creep specimen had more than 5 per cent rupture strain.
Theory of Time-Dependent Rupture and Interpretation of Some Stress-Rupture Data
Authors: Frey D. N.
Published: September 2009

When considering the significance of several types of elevated temperature rupture test results, the theory of such rupture should be considered. This serves as a rationale for the interpretation of the test results and can lead to certain more general conclusions.
Effect of Sigma on Strength and Ductility of 25 Cr, 20 Ni Steel
Authors: Smith G. V. , Dulis E. J.
Published: September 2009

Sigma in 25 Cr, 20 Ni austenitic stainless steel causes moderate strengthening at room temperature, severe loss in toughness even at temperature as high as 500 F, and moderate loss of creep-rupture strength at 1300 F.
Resistance of Copper Alloys to Atmospheric Corrosion
Authors: Tracy A W
Published: September 2009

Resistance to corrosion by natural outdoor atmospheres is an important property of metals. The exposure tests conducted by A.S.T.M. Committee B-3 on Corrosion of Non-Ferrous Metals and Alloys, which have now reached the 10-yr. mark, have added a large amount of data to the existing literature on the atmospheric corrosion of non-ferrous metals. It is the purpose of the present paper to correlate and discuss the data on copper alloys obtained from the tests carried out by Subcommittee VI on Atmospheric Corrosion of Committee B-3.
The Resistance of Aluminum-Base Alloys to Atmospheric Exposure
Authors: Dix E H , Mears R B
Published: September 2009

This paper comprises a discussion of the aluminum-base alloy specimens exposed in the atmospheric corrosion tests conducted by the American Society for Testing Materials through Subcommittee VI on Atmospheric Corrosion, of Committee B-3 on Corrosion of Non-Ferrous Metals and Alloys. Also included are results of atmospheric exposure tests conducted by the Aluminum Research Laboratories with similar and additional aluminum alloys.
Field and Laboratory Tests for Durability and Permanence: Adhesives Belonging to The Rubber-Resins Systems
Authors: Anderson J F , Fiedler L F
Published: September 2009

This paper concerns itself with a limited group of adhesives which has come into use for such purposes as bonding friction materials to metals, such as brake bonding and bonding, metal to metal, such as secondary structures in automotive and aeronautical industries. These adhesives are discussed from their (a) relationship to other types of joining, (b) relationships to other adhesives, (c) laboratory tests for evaluation of the adhesives and of the bonds, and (d) field tests which indicate the utility and practicability of the adhesives as engineering materials.
The Correlation Between Fluorescent X-ray Intensity and Chemical Composition
Authors: Sherman J
Published: September 2009

This discussion on correlation of fluorescent X-ray intensity with concentration is based on data produced under the following experimental conditions. The X-ray tube was operated mainly at 50 peak kv (occasionally at 35) with the d-c tube current ranging from about 5 to 40 ma. The dispersing or diffracting element was a curved mica crystal and the receiver a “thyrode” or multiplechamber Geiger counter. The specimens were usually metallic, although oxide mixtures were used from time to time. The incident beam was directed vertically downward and the specimen held at an angle of 30 deg to the horizontal. Hence, the grazing angle was 60 deg for the incident beam and 30 deg for the fluorescent beam. The specimens were composed of chromium, iron, cobalt, nickel, copper, zinc, and molybdenum, either in the form of commercially pure metal or oxide or binary or ternary mixtures with the concentrations of an element varying from about 10 to 90 per cent. The method of measurement was to read the time, T, with a clock recording directly to 0.01 sec, for the counter to record a fixed number of counts, N, equal to 218 or 262,144. The true counting rates varied from about 50 to 10,000 counts per sec. If a measurement is expressed as a time, T, it will mean the time for the counter to record 218 counts. The intensity of an X-ray spectrum line may be given either as a time, T, or a rate—that is, N/T as counts per second.
Report of Subcommittee VI, of Committee B-3, on Atmospheric Corrosion
Authors: Copson H. R.
Published: September 2009

The 20-yr results on 24 non-ferrous metals and alloys which were exposed to the atmosphere at seven locations are tabulated in this report. The locations and actual exposure times are listed in Table I.
Effect of Natural Atmospheres on Copper Alloys: 20-Year Test
Authors: Tracy A. W.
Published: September 2009

This paper discusses the corrosion resistance of eleven copper alloys exposed to industrial, marine, and rural atmospheres over a period of 20 yr. The evaluation is based on weight-loss measurements and changes in mechanical properties of sheet specimens.
Atmospheric Galvanic Corrosion of Magnesium Coupled to Other Metals
Authors: Teeple H. O.
Published: September 2009

For many years ASTM has been interested in the corrosion behavior of dissimilar metal galvanic couples. Several tests have been set up with exposures to a variety of outdoor atmospheres. The results of some of this work have been reported and have been widely used by both the designer and user of metallic structures.
The Use of Lead and Tin Outdoors
Authors: Hiers G. O. , Minarcik E. J.
Published: September 2009

The present paper is a partial summary of the 20-yr atmospheric tests conducted by Subcommittee VI on Atmospheric Corrosion of ASTM Committee B-3 on Corrosion of Non-Ferrous Metals and Alloys.
Compilation of Chemical Compositions and Rupture Strengths of Super-Strength Alloys
Authors: Simmons Ward F. , Krivobok V. N.
Published: September 2009

This compilation lists the name, nominal chemical composition, characteristic rupture strengths for rupture in 100 and 1000 hr, and patentee for approximately 163 domestic and 75 foreign alloys. The compilation includes the ferritic (martensitic) alloys and age-hardening stainless steels. It does not include the conventional austenitic stainless steels.
The Microstructure of Bronze Sinterings
Authors: Lowe E. W. , Biehl H. R.
Published: September 2009

This is a study of the changes which occur in the microstructure of sintered bronze under various conditions with respect to selected sintering variables. The study is based on color photomicrographs of the structures developed. Visual and quantitative evaluations of the pictures are presented. The report is part of a broad study of the properties of sintered bronze which is being conducted by members of ASTM Committee B-9 on Metal Powders and Metal Powder Products. Other reports are expected to be prepared when sufficient data have been developed. Sintered bronze has been a major production item of the powder metallurgy industry for more than 35 years. During this period, various studies have been made of the changes that take place during the sintering of briquets made from a mixture of copper and tin powder. Colored photomicrographs taken by Hall show phase changes occurring during the sintering of a bronze containing 9 per cent tin and 6 per cent graphite at 1490 F. Studies of the formation of copper-tin alloys were made by Duwez on the basis of X-ray diffraction patterns and thermal expansion measurements. The process of homogenization of bronze during sintering has been studied by Rhines and his co-workers. A comprehensive review of the subject was made by Lenel in 1948. Since that time, considerable progress has been made toward standardization for metal powder products. This activity has led to the present study to obtain a better fundamental understanding of the microstructural changes which occur in a standard bronze material sintered according to conditions approximating commercial practices.
Phase Designations of Alloys Appearing in the Powder Diffraction Data File Sections 1 to 12
Authors: Wfissmann S.
Published: September 2009

This supplementary brochure lists the alloy phases of the X-Ray Powder Diffraction File of Sections 1 to 12 in accordance with the Method of Assigning Phase Designations in Metallic Systems (ASTM Designation: E 157–61 T) developed by ASTM Committee E-4 on Metallography. In order to facilitate the correlation of the list of alloy phases with the Index of the X-Ray Powder Diffraction File, the corresponding card number, name of the alloy, and three strongest lines are also listed. The alloy systems have been listed in alphabetical order and they include also alloys of the nonmetals where, in general, the nonmetal of small atomic radius may form interstitial solid solutions. Thus the hydrides, borides, carbides, nitrides, and oxides of the metals and alloys are included in this list. The new phase designation aims to eliminate the confusion which has been introduced in the literature by the indiscriminate assignment of Greek and Roman letters to various alloy phases. Such indiscriminate usage resulted frequently in the assignment of different letters to the same phase, or, conversely, to the assignment of one letter to different phases. To avoid this pitfall the ASTM scheme of phase designation is based on composition and crystal lattice.
Creep Damage in Metals
Authors: Freeman J. W. , Voorhees H. R.
Published: September 2009

The use of alloys under conditions where creep occurs results in continuous accumulation of “damage” to the mechanical properties. Design must therefore consider what amount of creep can be tolerated during the required service life. In some cases the allowable creep is considerably less than one percent plastic strain. In other applications the governing criterion is failure by rupture, which may or may not be accompanied by relatively large amounts of creep strain. Because creep is a continuing process leading to failure, it can be considered to introduce increasing amounts of “damage” with increasing time in service. The damage accompanying creep may result from: (1) the plastic flow of creep, (2) the structural changes, which are thermally or strain induced, (3) the loss of elements (for example, decarburization), or the introduction by reaction and diffusion of contaminants from the environment, or surface damage arising from corrosion. With extensive use of alloys under creep conditions, and especially with more and more applications accumulating prolonged service times approaching design life, the following questions are raised with increasing frequency and urgency: (1) What is the remaining creep-service life of the material? (2) What damage to other mechanical properties arises from creep service? (3) Can the service life be extended by re-heat treatment during creep service? This paper presents a survey of the literature on creep damage. It was designed to produce answers to these three questions and to cover other pertinent aspects of the problem. The effects of corrosion and other surface reactions were omitted in so far as possible because they are highly dependent on the specific conditions of service or testing. Also no attempt was made to analyze the data in the light of the extensive literature on the fundamental processes of creep in metals and alloys.
The Elevated-Temperature Properties of Stainless Steels
Authors: Simmons Ward F. , Cross Howard C.
Published: September 2009

This report is essentially a graphical summary of elevated-temperature data for the commercially produced stainless steels. Included are summary curves for tensile strength, 0.2 per cent offset yield strength, per cent elongation, per cent reduction of area, stresses for rupture in 100, 1000, 10,000, and 100,000 hr, and stress for creep rates 0.0001 and 0.00001 per cent per hr (1 per cent in 10,000 and 100,000 hr). An Appendix is included, which contains the primary data from which the summary curves were drawn. The data sheets in the Appendix also give the chemical composition, processing data, and other pertinent information about the steels included in this survey.
General Information
Authors: Dana A. W. , Friend W. Z.
Published: September 2009

A necessary adjunct to the ASTM-NACE questionnaire on the stress-corrosion cracking of stainless steels was the gathering of background or general information data. A series of questions was, therefore, devised to establish the extent of the problem and to learn what industry is doing to overcome the incidence of cracking. This portion of the report summarizes the situation as it now exists. For convenience, the questions are stated individually and the answers interpreted.
Steps Taken to Overcome Cracking
Authors: Bloom F. K.
Published: September 2009

In about three fourths of the case histories some comment was made on this question. As might be expected, in many-instances the investigator could not state whether the recommended change had been carried out or, if so, if it was effective. In the following summary of the replies it was felt best to list both the total number of suggestions for some particular change and the number of cases where such a change was recorded as being successful. The various steps recommended were broadly classified into the three catagories: (1) change in material, (2) change in corrosion environment, or (3) reduction of stress. Each category was then further broken down as seemed appropriate. The results of this classification are shown in Table I.
Evaluation of Compression Set of Vulcanized Elastomers—Standard versus Variable Deflection Methods
Authors: King William H. , Harding Robert E.
Published: September 2009

The standard method for measuring the compression set of vulcanized elastomers (ASTM Methods D 395 - 55) covers two test procedures using different types of load applications. The first, method A, uses a constant load. The second, method B, which uses a constant deflection, is the more popular method and the one under consideration in this paper. The device for measuring compression set in accordance with method B consists of two or more flat steel plates. It is between the parallel faces of these plates that the specimens are compressed. The four levels of compression set employed in method B are dependent on the hardness of the material being tested according to the following table: The compression set, C, expressed as a percentage of the original deflection is calculated as follows: C=to−tlto−ts×100 where: to = original thickness of the test specimen, tl = thickness of the test specimen 30 min after removal from the test fixture, and ts = thickness of the spacer bar.
Foreword
Authors: Harris Jay C.
Published: September 2009

The volume of publications concerned with metal cleaning continues at a level comparable with previous years, but the emphasis has gradually changed. New metals present new cleaning problems which are solved by advanced technics or combinations of older methods. Ultrasonic cleaning, in-place cleaning of equipment in plants or of pipe lines, and the cleaning of electronic components are receiving much consideration for the special problems involved. Over 100 references prior to 1958 have been found, those from 1958 to early 1960 totalling 114. As before, indices of subject, author, specification and patent numbers have been provided. While the references are numbered consecutively, additional references that fall within the dates previously covered have capital letters appended to the numbers to indicate their correct position, while still later references to be inserted where capital letters are already assigned have been given lower case letters (for example 72, 72A, 72Aa) to indicate reference priority. Covered are the fields of practical application, laboratory evaluation, theory, and references from other fields applicable to the subject.
Retrograde Intraflagellar Transport Mutants Identify Complex A Proteins With Multiple Genetic Interactions inChlamydomonas reinhardtii
Authors: Iomini Carlo , Li Linya , Esparza Jessica M , Dutcher Susan K
Published: September 2009

The intraflagellar transport machinery is required for the assembly of cilia. It has been investigated by biochemical, genetic, and computational methods that have identified at least 21 proteins that assemble into two subcomplexes. It has been hypothesized that complex A is required for retrograde transport. Temperature-sensitive mutations in FLA15 and FLA17 show defects in retrograde intraflagellar transport (IFT) in Chlamydomonas. We show that IFT144 and IFT139, two complex A proteins, are encoded by FLA15 and FLA17, respectively. The fla15 allele is a missense mutation in a conserved cysteine and the fla17 allele is an in-frame deletion of three exons. The flagellar assembly defect of each mutant is rescued by the respective transgenes. In fla15 and fla17 mutants, bulges form in the distal one-third of the flagella at the permissive temperature and this phenotype is also rescued by the transgenes. These bulges contain the complex B component IFT74/72, but not α-tubulin or p28, a component of an inner dynein arm, which suggests specificity with respect to the proteins that accumulate in these bulges. IFT144 and IFT139 are likely to interact with each other and other proteins on the basis of three distinct genetic tests: (1) Double mutants display synthetic flagellar assembly defects at the permissive temperature, (2) heterozygous diploid strains exhibit second-site noncomplemention, and (3) transgenes confer two-copy suppression. Since these tests show different levels of phenotypic sensitivity, we propose they illustrate different gradations of gene interaction between complex A proteins themselves and with a complex B protein (IFT172).
Quantitative Genetic Bases of Anthocyanin Variation in Grape (Vitis viniferaL. ssp.sativa) Berry: A Quantitative Trait Locus to Quantitative Trait Nucleotide Integrated Study
Authors: Fournier-Level Alexandre , Le Cunff Loïc , Gomez Camila , Doligez Agnès , Ageorges Agnès , Roux Catherine , Bertrand Yves , Souquet Jean-Marc , Cheynier Véronique , This Patrice
Published: September 2009

The combination of QTL mapping studies of synthetic lines and association mapping studies of natural diversity represents an opportunity to throw light on the genetically based variation of quantitative traits. With the positional information provided through quantitative trait locus (QTL) mapping, which often leads to wide intervals encompassing numerous genes, it is now feasible to directly target candidate genes that are likely to be responsible for the observed variation in completely sequenced genomes and to test their effects through association genetics. This approach was performed in grape, a newly sequenced genome, to decipher the genetic architecture of anthocyanin content. Grapes may be either white or colored, ranging from the lightest pink to the darkest purple tones according to the amount of anthocyanin accumulated in the berry skin, which is a crucial trait for both wine quality and human nutrition. Although the determinism of the white phenotype has been fully identified, the genetic bases of the quantitative variation of anthocyanin content in berry skin remain unclear. A single QTL responsible for up to 62% of the variation in the anthocyanin content was mapped on a Syrah × Grenache F1 pseudo-testcross. Among the 68 unigenes identified in the grape genome within the QTL interval, a cluster of four Myb-type genes was selected on the basis of physiological evidence (VvMybA1, VvMybA2, VvMybA3, and VvMybA4). From a core collection of natural resources (141 individuals), 32 polymorphisms revealed significant association, and extended linkage disequilibrium was observed. Using a multivariate regression method, we demonstrated that five polymorphisms in VvMybA genes except VvMybA4 (one retrotransposon, three single nucleotide polymorphisms and one 2-bp insertion/deletion) accounted for 84% of the observed variation. All these polymorphisms led to either structural changes in the MYB proteins or differences in the VvMybAs promoters. We concluded that the continuous variation in anthocyanin content in grape was explained mainly by a single gene cluster of three VvMybA genes. The use of natural diversity helped to reduce one QTL to a set of five quantitative trait nucleotides and gave a clear picture of how isogenes combined their effects to shape grape color. Such analysis also illustrates how isogenes combine their effect to shape a complex quantitative trait and enables the definition of markers directly targeted for upcoming breeding programs.
Dissection of Genetic Factors Modulating Fetal Growth in Cattle Indicates a Substantial Role of the Non-SMC Condensin I Complex, Subunit G (NCAPG) Gene
Authors: Eberlein Annett , Takasuga Akiko , Setoguchi Kouji , Pfuhl Ralf , Flisikowski Krzysztof , Fries Ruedi , Klopp Norman , Fürbass Rainer , Weikard Rosemarie , Kühn Christa
Published: September 2009

The increasing evidence of fetal developmental effects on postnatal life, the still unknown fetal growth mechanisms impairing offspring generated by somatic nuclear transfer techniques, and the impact on stillbirth and dystocia in conventional reproduction have generated increasing attention toward mammalian fetal growth. We identified a highly significant quantitative trait locus (QTL) affecting fetal growth on bovine chromosome 6 in a specific resource population, which was set up by consistent use of embryo transfer and foster mothers and, thus, enabled dissection of fetal-specific genetic components of fetal growth. Merging our data with results from other cattle populations differing in historical and geographical origin and with comparative data from human whole-genome association mapping suggests that a nonsynonymous polymorphism in the non-SMC condensin I complex, subunit G (NCAPG) gene, NCAPG c.1326T>G, is the potential cause of the identified QTL resulting in divergent bovine fetal growth. NCAPG gene expression data in fetal placentomes with different NCAPG c.1326T>G genotypes, which are in line with recent results about differential NCAPG expression in placentomes from studies on assisted reproduction techniques, indicate that the NCAPG locus may give valuable information on the specific mechanisms regulating fetal growth in mammals.
Cross-Species RNAi Rescue Platform in Drosophila melanogaster
Authors: Kondo Shu , Booker Matthew , Perrimon Norbert
Published: September 2009

RNAi-mediated gene knockdown in Drosophila melanogaster is a powerful method to analyze loss-of-function phenotypes both in cell culture and in vivo. However, it has also become clear that false positives caused by off-target effects are prevalent, requiring careful validation of RNAi-induced phenotypes. The most rigorous proof that an RNAi-induced phenotype is due to loss of its intended target is to rescue the phenotype by a transgene impervious to RNAi. For large-scale validations in the mouse and Caenorhabditis elegans, this has been accomplished by using bacterial artificial chromosomes (BACs) of related species. However, in Drosophila, this approach is not feasible because transformation of large BACs is inefficient. We have therefore developed a general RNAi rescue approach for Drosophila that employs Cre/loxP-mediated recombination to rapidly retrofit existing fosmid clones into rescue constructs. Retrofitted fosmid clones carry a selection marker and a phiC31 attB site, which facilitates the production of transgenic animals. Here, we describe our approach and demonstrate proof-of-principle experiments showing that D. pseudoobscura fosmids can successfully rescue RNAi-induced phenotypes in D. melanogaster, both in cell culture and in vivo. Altogether, the tools and method that we have developed provide a gold standard for validation of Drosophila RNAi experiments.
Infrared Ellipsometry Investigation of Hydrogenated Amorphous Silicon
Authors: Gaspari Franco , Shkrebtii Anatoli , Tiwald Tom E. , Fuchser Andrea , Ahmed Shafiq Muhammad , Kosteski Tome , Leong Keith , Kherani Nazir
Published: September 2009

Hydrogenated amorphous silicon (a-Si:H) has been extensively investigated experimentally in the infrared spectral region via techniques such as Fourier Transform Infrared (FTIR) and Raman spectroscopy. Although spectroscopic ellipsometry has been proven to be an important tool for the determination of several parameters of a-Si:H films, including dielectric constant, surface roughness, doping concentration and layer thickness, the spectral range used in these studies has rarely covered the infrared region below 0.6 eV, and never over the complete spectral region of interest (0.04 – 0.3 eV).
We have measured for the first time the dielectric function of a-Si:H films grown by the
saddle field glow discharge technique by spectroscopic ellipsometry in the energy range from 0.04 eV to 6.5 eV, thus extending the analysis into the far infrared region. The a-Si:H films were deposited on germanium substrates for the ellipsometry studies, and on crystalline silicon substrates for the comparative FTIR analysis. Preparation parameters were chosen to obtain films with different hydrogen content. In this paper, we present the results of the ellipsometry analysis, evaluate different fitting techniques, and compare the results with the corresponding FTIR spectra. The similarities and differences between the spectra are discussed in terms of the a-Si:H properties.
Effect Of Trapping On Dielectric Conduction Mechanisms Of ULK/Cu Interconnects
Authors: Verrière Virginie , Guedj Cyril , Roy David , Blonkowski Serge , Sylvestre Alain
Published: September 2009

Trapping in low-κ dielectric for interconnects was highlighted by voltage shift in IV current-voltage measurements. It is shown that effects of trapping can impact the extraction of conduction mechanisms. Capacitance measurements made on these materials reveal that trapping is at the origin in the increase of capacitance. The creation of dipoles because of this trapping explains this increase in the value of capacitance.
Dual Damascene Reactive Ion Etch Polymer Characterization through X-Ray Photoelectron Spectroscopy for 65 nm and 45nm Technology Nodes
Authors: Choi Samuel , Dziobkowski Chet , Tai Leo
Published: September 2009

At 65nm and beyond technology nodes, copper interconnect formation in dual damascene integration is continually challenged from a polymer management perspective. Highly polymeric plasma chemistry is required to reduce line edge roughness, shape physical profile, and control critical dimension across a 300mm wafer. But too much fluorocarbon deposition on a wafer results in poor defects yield.

In this paper, X-ray photoelectron spectroscopy (XPS) characterization technique is used to quantify and to optimize a metal line reactive ion etch process to increase electrical opens yield. A reduction of 2 at.% in carbon mass results in a Do (defects/cm2) improvement from > 2.0 to less than 1.0. This result is realized without a shift to the trench physical profile which is important for reliability performance. Moreover, with a shorter turnaround time of XPS characterization compared to electrical hardware splits, quicker yield learning cycle is realized for both RIE process and module integration.
Characterization of Plasma Damage in Low-k Films by TVS Measurements
Authors: Ciofi Ivan , Baklanov Mikhail R. , Calbo Giovanni , Tőkei Zsolt , Beyer Gerald
Published: September 2009

We evaluated Triangular Voltage Sweep (TVS) measurements as a technique to characterize plasma damage in low-k films. Blanket wafers with low-k films of different porosity and k value were prepared. Our samples included an SiOC:H material with 7% porosity and k value of 3.0, deposited on 200mm wafers, and two SiOC:H materials with 25% porosity and k value of 2.5, deposited on 300mm wafers. Before deposition, a thin layer of dry thermal oxide (2 – 5 nm) was grown on the n-type wafers to stabilize the silicon interface. After deposition, low-k films were exposed to N2/H2 plasma for different times in order to induce different degree of plasma damage. Untreated low-k films were always included as a reference. For electrical measurements, metal dots were deposited on pieces to fabricate Metal-Insulator-Semiconductor capacitors.

TVS measurements were performed at 190°C on the different samples. On samples exposed to N2/H2 plasma, we detected a current peak in the TVS trace, whose magnitude increased with exposure time to plasma. No peaks were detected on untreated films. This indicates that TVS measurements are sensitive to plasma damage. Furthermore, TVS results correlated well with FTIR spectra that showed increasing damage and H2O uptake with increasing exposure time to plasma. We conclude that TVS measurements are suitable for characterizing the degree of plasma damage in low-k films and complement well materials analysis, because with the help of TVS a link to leakage properties can be made. As an application, we used TVS measurements for evaluating restoration of plasma damaged low-k films by long N2-bake at high temperature. Wafer pieces from each sample were baked at 350°C for 4h30min in N2 atmosphere. A few pieces were measured immediately after baking. The remaining pieces were either left exposed to ambient for a few days or dipped in deionized H2O for a few hours to evaluate recovery of hydrophobic properties. The different treatments (N2-bake, exposure to ambient, H2O dipping) were always performed on blanket wafer pieces. Metal dots for electrical measurements were only deposited after the treatment. CV and FTIR measurements were performed before and after treatments to evaluate change in k-value and material structure, respectively. Our data show that long N2-bake at high temperature can partially restore damaged low-k films. The magnitude of the damage-related TVS peak was significantly reduced after heat treatment and remained stable even after H2O dipping. CV measurements performed on baked pieces after 6 days of exposure to ambient showed a reduced k-value. Consistently, FTIR spectra showed a significant reduction of H2O content soon after baking. The materials remained stable over several days and only minor reincorporation of H2O occurred after exposure to ambient or H2O dipping. Therefore, long N2-bake at high temperature can partially restore leakage (TVS), k-value (CV) and hydrophobic properties (FTIR) of damaged low-k films.
Coupled Finite Element–Potts Model Simulations of Grain Growth in Copper Interconnects
Authors: Radhakrishnan Bala , Sarma Gorti
Published: September 2009

The paper addresses grain growth in copper interconnects in the presence of thermal expansion mismatch stresses. The evolution of grain structure and texture in copper in the simultaneous presence of two driving forces, curvature and elastic stored energy difference, is modeled by using a hybrid Potts model simulation approach. The elastic stored energy is calculated by using the commercial finite element code ABAQUS, where the effect of elastic anisotropy on the thermal mismatch stress and strain distribution within a polycrystalline grain structure is modeled through a user material (UMAT) interface. Parametric studies on the effect of trench width and the height of the overburden were carried out. The results show that the grain structure and texture evolution are significantly altered by the presence of elastic strain energy.
Electronic Transport Properties of Cu/MnOx/SiO2/p-Si MOS Devices
Authors: Dixit Vijay Kumar , Neishi Koji , Koike Junichi
Published: September 2009

An ultrathin barrier layer of MnOx was grown using metal organic chemical vapor deposition (MOCVD) at an interface between Cu and SiO2 dielectric. The electronic transport properties of Cu/MnOx/SiO2/p-Si metal oxide semiconductor (MOS) devices showed leakage current density within the range of 10-8-10-7A/cm2 up to an electric field of 4MV/cm. The current density remained within the same range after bias temperature aging test at 3MV/cm for 6×103s at 550K. The capacitance-voltage curves of the MOS device having the MnOx layer grown at 473K do not show significant shift of flat band voltage after thermal annealing at 673K for 3.6×103s as well as after bias temperature aging test at 1MV/cm, 550K for 2.4×103 s. These results indicate that the ultrathin layer of MnOx is stable under the above conditions and prevents sufficiently Cu ion diffusion into the SiO2 dielectric.
A Novel X-ray Diffraction –based Technique for Complete Stress State Mapping of Packaged Silicon Dies
Authors: Raghothamachar Balaji , Sarkar Vishwanath , Noveski Vladimir , Dudley Michael , Sharan Sujit
Published: September 2009

Fundamental understanding of the silicon stresses and their changes with traditional wire-bonded and flip chip packages is critical to address the performance and reliability improvements in new technologies. Recently we have developed a novel technique for non-destructive measurements of complete strain state (and thereby the stress state) of the single crystal (bulk Si) by tracing the relative change in direction of an x-ray beam diffracted from a stressed crystal. This is based on the relationship between the stress state in a crystal and the local lattice plane orientation. Experimentally, this can be achieved by using a large area synchrotron white beam in conjunction with a precision grid of x-ray absorbing material placed in the path of the beam. The grid breaks the X-ray beam into an array of micro-beams that are diffracted by the single crystal sample to produce an integrated x-ray topograph on which the inverse grid image is distorted due to changes in the paths of diffracted microbeams i.e. an x-ray reticulograph is created. The distortions are a result of the variations in the diffracting lattice plane orientation produced by strain present in the crystal. By measuring this distortion on multiple topographs through the electronic package and applying the ray tracing principle, the entire strain state of the silicon can be calculated and mapped for the entire sample. We have carried out stress mapping of the silicon device in the package by applying this non-destructive and non-invasive technique.
Local Bonding Asymmetries in Ge-As-Se Glasses
Authors: Mammadov Eldar , Taylor Craig , Baker David , Bobela David , Reyes Arneyl , Kuhns Philip , Mehdiyeva Salima
Published: September 2009

High magnetic fields up to 22 T have been applied to determine the local bonding asymmetries in the Ge2As2Se7 and Ge2As2Se5 glasses by 75As NMR. The results are analyzed using computer simulations of the line-shape. The asymmetry parameter η of the electric field gradient at arsenic sites in Ge2As2Se7 is found to be about 0.2, indicating that the dominant arsenic structural units in the composition are nearly axially symmetric pyramids. In the Ge2As2Se5 glass, however, the 75As NMR spectrum exhibits no well-resolved structure, revealing the existence of highly asymmetric sites. The experimental data are fitted using the previously obtained distribution of quadrupole coupling constants from pulsed 75As NQR experiments. These NMR simulations assume a broad distribution of the asymmetry parameter. The results are in agreement with the NQR studies in the same compositions.
Two-Junction GaAs/Ge Cells With Three Terminals for PV and CPV Applications
Authors: Emziane Mahieddine
Published: September 2009

The present investigation deals with a two-junction device having GaAs as the top cell and Ge for the bottom cell on a Ge substrate. Compared with the conventional two-terminal device configuration, three terminals avoid the loss due to current mismatching between the cells, and the resistance loss originating from the tunnel junction between the cells. Device structures were investigated and optimized with regard to the thicknesses and doping levels of both top and bottom active junctions that lead to the highest device performance. Due to the split of the incident solar spectrum between GaAs and Ge cells, the latter only receives the light to which the former is transparent (mainly in the near infrared) and therefore behaves differently from a single-junction Ge cell. Optimal current-voltage and power-voltage characteristics were generated for individual cells together with the corresponding device PV parameters. The predictions show that an extended spectral coverage is achieved leading to an enhanced overall power output from the devices. The potential applications of these devices in conventional as well as concentrator PV were assessed and discussed as a function of the simulated concentration ratio of the incident light under AM1.5 illumination conditions. We have shown that a relatively thin double-junction GaAs/Ge device can achieve a remarkably high power output.
High Optical Absorption of Indium Sulfide Nanorod Arrays Formed by Glancing Angle Deposition
Authors: Cansizoglu Mehmet , Engelken Robert , Seo Hye-Won , Karabacak Tansel
Published: September 2009

Indium (III) sulfide has recently attracted much attention due to its potential in optical sensors as a photoconducting material and in photovoltaic applications as a wide direct bandgap material. On the other hand, optical absorption properties are key parameters in developing highly photosensitive photodetectors and high efficiency solar cells. We show that indium sulfide nanorod arrays produced by glancing angle deposition techniques have superior absorption and low reflectance properties compared to conventional flat thin film counterparts. We observed an optical absorption value of approximately 96% for nanorods, in contrast to 80% for conventional amorphous-to-polycrystalline thin films of indium sulfide. A photoconductivity response was also observed in the nanorod samples, whereas no measurable photoresponse was detected in conventional thin films. We give a preliminary description of the enhanced light absorption properties of the nanorods by using Shirley-George Model that predicts enhanced diffuse scattering and reduced reflection of light due the rough morphology.