Middle Of Line Research Articles

ASAP7: A 7-nm finFET predictive process design kit

We describe a 7-nm predictive process design kit (PDK) called the ASAP7 PDK, developed in collaboration with ARM Ltd. for academic use. The PDK is realistic, based on current assumptions for the 7-nm technology node, but is not tied to any specific foundry. The initial version assumes EUV lithography for key layers, a decision based on its present near cost-effectiveness and resulting simpler layout rules. Non-EUV layers assume appropriate multiple patterning schemes, i.e., self-aligned quadruple patterning (SAQP), self-aligned double patterning (SADP) or litho-etch litho-etch (LELE), based on 193-nm optical immersion lithography. The specific design rule derivation is explained for key layers at the front end of line (FEOL), middle of line (MOL), and back end of line (BEOL) of the predictive process modeled. The MOL and BEOL DRC rules rely on estimation of time dependent dielectric breakdown requirements using layer alignments determined with projected machine to machine overlay assumptions, with significant guard-bands where possible. A high density, low-power standard cell architecture, developed using design/technology co-optimization (DTCO), as well as example SRAM cells are shown. The PDK transistor electrical assumptions are also explained, as are the FEOL design rules, and the models include basic design corners. The transistor models support four threshold voltage (Vth) levels for both NMOS and PMOS transistors. Cadence Virtuoso technology files and associated schematic and layout editing, as well as netlisting are supported. DRC, LVS, and full parasitic extraction is enabled through Mentor Calibre decks.

(Keynote) Challenges of 10 Nm and 7 Nm CMOS for Server and Mobile Applications

CMOS scaling has served the semiconductor industry and transformed the world exceedingly successfully over the past several decades. In recent times, the transition to hi-K dielectric interfaces enabled CMOS to shrink circuits to below the 32nm node. The advent of fully depleted devices (FDSOI, FINFETs) have enabled CMOS scaling to the limits of conventional 193nm optical immersion lithography. Over the past decade, CMOS scaling has transformed mobile technologies. The cell phone and smartphone have become ubiquitous as increased performance has been garnered to increase functionality on the form factor at constant power (Watt regime). The resulting boom in data has transformed industries and fueled the social network and the "app" world. 14nm FINFET technology is now available on cutting edge mobile devices. The 10nm node will see various incarnations across the major semiconductor fabricators. The pressure on density to reduce cost will result in the adoption of multiple patterning techniques for the FIN, Gate and various MIddle Of Line (MOL) and Back End Of Line (BEOL) wiring levels. The need to reduce doping in the FINFETs will result in Multi-Workfunction-Gates. Novel materials will be needed to reduce parasitic capacitance and resistance in the MOL and BEOL levels. Some incarnations of the 10nm node will be called "7nm", but the true "7nm" node circuit densities will require the next generation of lithography -- Extreme Ultra Violet (EUV) at 13.6nm wavelength. The key to adoption in the commodotized mobile space is thus the cost of the chip which is challenged by the need for novel cost intensive patterning techniques and new materials. While power and form factor are key to the mobile world, Server applications have required performance at much higher power (100+ Watt regime). CMOS scaling has served this market very well over the decades as improved transitors have always been utilized for increased performance (high end servers run > 5 GHz). The growth in the server market has migrated to large datacenters for cloud applications and away from standard transaction processing (which still remains important in many areas). Parasitic components on FINFETs are thus much more critical in this market and has thus driven early adoption of "next generation" materials and processes. The adoption of 10nm and 7nm nodes in this space will be determined less by cost than by ability to get better performance at constant chip power given the increased parasitics in the MOL and BEOL. This drives the need for introduction of new novel materials for improved performance and reliability.

Systematic framework for evaluating standard cell middle-of-line robustness for multiple patterning lithography

For robust standard cell design, designers need to improve the intercell compatibility for all combinations of cells and cell placements. Multiple patterning lithography colorability check breaks the locality of traditional rule check, and N-wise checks are strongly needed to verify the colorability for layout interactions across cell boundaries. A systematic framework is proposed to evaluate the library-level robustness over multiple patterning lithography from two perspectives, including complete checks on two-row combinations of cells and long-range interactions. With complete checks on two-row combinations of cells, the vertical and horizontal boundary checks are explored to predict illegal cell combinations. For long-range interactions, random benchmarks are generated by cell shifting and tested to evaluate the placement-level efforts needed to reduce the manufacturing complexity from quadruple patterning lithography to triple patterning lithography for the middle-of-line (MOL) layers. Our framework is tested on the MOL layers but can be easily adapted to other critical layers with multiple patterning lithography constraints.

Breakdown data generation and in-die deconvolution methodology to address BEOL and MOL dielectric breakdown challenges

Both middle-of-line (MOL) gate to contact spacer dielectric and back-end-of-line (BEOL) low-k dielectric breakdown data are commonly convoluted with multiple variables induced by process steps such as lithography, etch, chemical–mechanical polish (CMP), cleaning, and thin film deposition. The traditional method of stressing one device under test (DUT) per die or multiple DUTs per die, without careful data deconvolution, is incapable of addressing current complex MOL PC-CA and BEOL low-k dielectric breakdown modeling challenges. Generally, compound Weibull distributions in various unpredictable shapes induced by various die-to-die variations would be generated and such compound distributions could lead to a wrong low-percentile failure rate projection and a non-Poisson area scaling outcome. In this paper, a generation method plus an analytics procedure to analyze die-to-die variation is proposed to soundly evaluate both MOL and BEOL dielectric time-dependent-dielectric breakdown data. Relying on such die-to-die data generation and analytics, a diagnostic reliability concept is further proposed for comprehensive process diagnostics and more accurate reliability failure rate determination.

Optimizing Middle of Line (MoL) Contact Cleaning to Preserve Tungsten (W) Integrity in Advanced Technology Nodes

Advanced node (sub 2Xnm) chip manufacturing employs new fabrication techniques as well as materials. This work is focused on the Middle of Line (MoL) contact cleaning. An advanced cleaning process is developed based on the electrochemical compatibility and interactions between the chosen chemistry and exposed layers as well as contaminants to be removed. The cleaning efficacy in the trenches is verified by measuring contact resistance as well as particle/flake inspections. Tungsten integrity is verified with bright field microscopy and damage to inter layer dielectrics is monitored by measuring trench and contact critical dimensions. Other structural interactions were studied with TEM imaging. The new cleaning process yielded substantially higher number of functional die as compared to POR (Process of Record).

Optimizing Middle of Line (MoL) Contact Cleaning to Preserve Tungsten (W) Integrity in Advanced Technology Nodes

Most of the advanced technology node semiconductor device manufacturing has adopted the gate-last approach which utilizes a RMG (Replacement Metal-Gate) process. The gate last method prevents unnecessary thermal loading on the high-k gate material and the metal layers; typically induced due to high-temperature activation of the doping regions. In gate-last process, junctions are salicidized after RMG requiring a different patterning approach for the active regions, i.e. an additional TS (Trench Silicide) mask is used. Thus the contact to the active regions is split into two levels. First the TS is formed and filled with tungsten which is followed by conventional contact patterning. With the increased complexity of contact architecture, contact cleaning becomes more critical in preventing contact opens as well as in maintaining the structural integrity to eliminate risks of contact to gate shorts and trench fill (tungsten) erosion. In this work, an advanced cleaning process is developed based on the electrochemical compatibility and interactions between the chosen chemistry and exposed layers as well as contaminants to be removed. The cleaning efficacy in the trenches is verified by measuring contact resistance as well as particle/flake inspections. Tungsten integrity is verified with bright field microscopy and damage to inter layer dielectrics is monitored by measuring trench and contact critical dimensions. Other structural interactions were studied with TEM imaging. The new cleaning process yielded substantially higher number of functional die as compared to POR (Process of Record). This paper will detail and discuss the above mentioned mechanism and performance data.

番茄、玉米套种膜下滴灌条件下农田地温变化特征试验研究

PDF HTML阅读 XML下载 导出引用 引用提醒 番茄、玉米套种膜下滴灌条件下农田地温变化特征 DOI: 10.5846/stxb201303240506 作者: 作者单位: 内蒙古农业大学水利与土木建筑工程学院,内蒙古农业大学水利与土木建筑工程学院,内蒙古农业大学水利与土木建筑工程学院,水利部牧区水利科学研究所,内蒙古农业大学水利与土木建筑工程学院,内蒙古农业大学水利与土木建筑工程学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(51109105, 51349003); 国家科技支撑(2011BAD29B03); 内蒙古高等学校"青年科技英才支持计划"; 博士后基金(2011M500547, 2012T50250) The interplanting between tomato and maize of soil temperature dynamics under mulched drip irrigation Author: Affiliation: Water conservancy and civil engineering college of Inner Mongolia Agricultural University,Water conservancy and civil engineering college of Inner Mongolia Agricultural University,Water conservancy and civil engineering college of Inner Mongolia Agricultural University,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤水热状况是影响作物生长的重要因素,以膜下滴灌及套种双重效应为背景,针对番茄、玉米套种农田设置了高(番茄:180 mm,玉米:270 mm)、中(番茄:132 mm,玉米:202.5 mm)、低(番茄:84 mm,135 mm)3种不同的灌溉定额,采用定位监测法测定番茄带膜间裸地(A)、覆膜番茄行间(B)、番茄带与玉米带膜间裸地(C)、覆膜玉米行间(D)共4个位置的不同深度主根区含水率和地温动态变化,研究了地膜覆盖、土壤水分以及作物遮阴对套种农田不同行间,不同深度土壤温度的影响特征。结果表明:全生育期内,4个水平位置的地温大小顺序与土壤深度有关,10 cm以上的地温大小顺序为C > D > A > B,10 cm以下的地温大小顺序为D > B > A > C;从土壤温度场的分布情况来看,地温的最大变幅出现在C处,为8.10 ℃;最小变幅出现在B处,为4.71 ℃;含水率与地温的关系表现为:5 cm以上地温与含水率呈反比关系,20 cm以下地温与含水率呈正比关系。可见,套种覆膜滴灌农田合适的土壤水分状况将有利于根区良好水热的形成,从而更有利于作物的生长。研究结果将对西北地区滴灌农田管理有一定的参考价值。 Abstract:It is very significant for maintaining the optimal soil moisture and soil temperature in the crop field, because that is the important foundation of developing an optimal irrigation system. The environment of reasonable soil moisture and temperature in the field will not only enhance the water use efficiency but also benefit crop growth and increase crop yield, especially for interplanting field with complex crop environments. In the experiments, the interplanting of tomato and corn under mulched drip irrigation were tested in Hetao Irrigation District in 2012. We set up three treatments which are the high irrigation quota (tomato: 180 mm, corn: 270 mm), medium irrigation quota (tomato: 132 mm, corn: 202.5 mm) and low irrigation quota (tomato: 84 mm, corn: 135 mm). The moisture content and soil temperature of different depths of root zone were measured in the middle of bare soil between tomatoes belt (A), the middle of mulched tomato lines (B), the middle of bare soil between tomatoes and corn belt (C), the middle of mulched corn lines (D) and crop growth and yield were observed in different growing seasons. The effects of plastic film, soil moisture and crop shade on soil temperature at different rows and depths of inter-planting were studied by the experiment. The results showed that it had apparent effect of mulch on heat preservation under 15 cm soil depths, but the soil temperatures of whole root zone were influenced by crop shade and soil moisture; The soil temperatures of four horizontal positions were significant variation for different the soil depths (5 cm, 10 cm, 15 cm, 20 cm, 25 cm), and the proper sequence of average soil temperature above 10 cm soil depth in different positions was: C > D > A > B, the one under 10 cm soil depth was: D > B > A > C; The study on distribution of the soil temperature in the interplanting field showed that the maximum variational amplitude of soil temperature appeared at the C position, and it would reach 8.10 ℃; the minimum variational amplitude of soil temperature appeared in the B position, and it was only 4.71 ℃. There was definitely some inverse correlation between the soil temperature and soil moisture above 5 cm soil depth, however direct proportion was observed below 20 cm soil depth. The study also found that there was strong temperature effect in the middle of lines between high and low crops (such as C position) during daytime, and the temperature can influence the crop of two sides, so mulched cultivation has obvious effects for restraining the loss of heat. It is thus clear that the optimal soil water and soil temperature are beneficial to form better soil moisture and temperature environment and high crop yield in the intercropping field under mulched drip irrigation. The study will be very meaningful for drip irrigation farm management in the Northwest Region. 参考文献 相似文献 引证文献

Study on Very Fast Transient Overvoltage of Closing No-load China UHV Transmission Demonstration Project Jindongnan-Nanyang-Jingmen 1000 kV Transmission Lines

When the ultra high voltage (UHV) substation used the gas insulated switchgear (GIS) system to switch lines with capacitive current, the pre-breakdown and multiple reignition will occur between switching contacts. Because of discharge characteristics of SF6 and special structures of GIS system, the variations of the electromagnetic transient process and very fast transient overvoltage (VFTO) are very fast and extremely complex. The development process and characteristics of VFTO remain to be dealt with to seek effective suppression measures. The overvoltage of closing no-load long lines on GIS system is analyzed in detail. The simulation model of the very fast transient process of closing no-load long lines on UHV GIS system is established. The VFTO of closing no-load China UHV transmission demonstration project Jindongnan-Nanyang-Jingmen 1000 kV transmission lines is analyzed using electromagnetic transient simulation software ATP-EMTP. The VFTO of closing no-load long lines on UHV GIS system is simulated and calculated, when the system has no additional closing resistors and lightning arresters, additional single stage closing resistors, additional multistage closing resistors, lightning arresters in two terminals of lines, lightning arresters in two terminals and the middle of lines, and additional multistage closing resistors and lightning arresters in two terminals and the middle of lines. The simulation results show that the additional multistage closing resistors and lightning arresters in two terminals and the middle of lines can effectively restrain the VFTO of closing no-load long lines on UHV GIS system.

Optimal Location of Shunt Facts Devices For Power Flow Control

Power flow control, in an existing long transmission line, plays a vital role in Power System area. This paper employs the shunt connected compensation (STATCOM) based FACTS device for the control of voltage and the power flow in long distance transmission line. The proposed device is used in different locations such as sending end of the transmission line, middle and receiving end of the transmission line. The PWM control strategy is used to generate the firing pulses of the controller circuit. Simulations were carried out using MATLAB Simulink environment. The suitable location and the performance of the proposed model were examined. Based on a voltage-sourced converter, the STATCOM regulates system voltage by absorbing or generating reactive power. Contrary to a thyristor-based Static Var Compensator (SVC), STATCOM output current (inductive or capacitive) can be controlled independent of the AC system voltage. The simulation results reveals that the reactive power generated is better at the middle of the transmission line when compared with the other ends of the transmission line and also the voltage is controlled at the middle of the line. Henceforth the location of STATCOM is optimum when connected at the middle of the line.

When Scribes Won’t Write: Gaps in Middle English Books

When Scribes Won’t Write:Gaps in Middle English Books Daniel Wakelin “Ther lakketh no thyng to thyne <gap> eyen” Geoffrey spirleng, who copied the Canterbury Tales with his son in Norfolk in the 1470s, had a special concern with finishing. As he completed his copy, he wrote an elaborate colophon in a decorative handwriting modeled on textura, with a prayer ending “amen” and a proud description of himself and his son. Sadly he had stopped too soon. Because of problems in his exemplars, he had duplicated two tales and omitted two entirely. He noticed this omission and so crossed out his colophon with a note explaining that “the book of Canterbury is nat yet ended,” and added the missing tales after.1 The wording is telling. A scribe should not stop when the text “is nat yet ended”; a scribe should copy all of the text and only stop when it does. That makes it odd, then, that Spirleng does sometimes stop writing not at the end, nor even at the joins between Chaucer’s tales which gave many scribes pause, but in the middle of the text. He stops writing in the middle of lines before carrying on, leaving a gap or blank space: “Ther lakketh no thyng to thyne <gap> eyen,” he writes, for instance. The missing word is “outter.” He leaves a gap like this thirty-six times for passages shorter than [End Page 249] a line. Four other times he leaves a gap for a whole line.2 Spirleng is not alone among the copyists of English in leaving these little gaps of a line or less; lots do it. These are not, on inspection, erasures of words; the words were simply not written in the first place. What is going on when scribes won’t write? There are (as emerges below) two main causes for these gaps. The first sort of gap occurs when a scribe thinks that there is text missing from his exemplar and so leaves a space in order to slot in what’s missing later. As it happens, one of Spirleng’s exemplars survives, so we can see that there was one occasion when he left a whole line blank where his exemplar had skipped a line; he worked out that something was lost and so in his copy left room to supply it.3 There is a dislike of incompleteness here like that which made him retrieve two omitted tales after he had finished. The second sort of gap, though, occurs when a scribe does find the text in his exemplar but does not believe it is right or that he has read it rightly and so leaves a gap to solve the puzzle later. For instance, in nineteen other gaps for which Spirleng’s exemplar survives, the exemplar does have the word required but Spirleng leaves space for it. This second sort of gap is the main focus of this article. For leaving a gap deliberately seems odd, given his concern for completeness elsewhere. What were he and other scribes thinking when they refused to write the words they saw in their exemplars? Given the effort needed to let the pen jump forward, not writing thus looks like a conscious choice. As such, the gaps raise a larger question about how far scribes exercised agency in their work, and about the forms that agency might take in concentration, attention, precision, improvisation, intellection, invention. Did scribes think as they put pen to paper and, if so, what did they think about, how did they think? Matthew Fisher stresses that “writing is always intended. Whether that writing is composition or copying, medieval manuscripts did not come [End Page 250] into being by accident.”4 Yet the intention in copying can be invisible, especially when scribes do copy what is in front of them, in what Fisher calls “replicative” copying or Richard Beadle calls “verbatim copying.”5 Such copying entails following the exemplar from the beginning through to the end, in every word; it involves reproducing other people’s words and not one’s own; so the evidence for what the copyist thinks is sparse and implicit. In...

A robust 45 nm gate-length CMOSFET for 90 nm Hi-speed technology

We have developed a robust 45 nm gate-length CMOSFET for 90 nm node high performance application. Aggressive gate length and gate dielectric scaling along with optimized strain engineering enable high performance device similar to 65 nm node CMOSFET [Nakahara Y, et al. IEDM Tech Dig 2003;281] We have utilized oxy-nitride gate with post-nitridation anneal, high ramp rate spike anneal, low temperature spacer scheme and stress controlled SiN contact etch stop liner process in order to improve drive current as well as transistor short-channel roll-off. In particular, we will focus on the study of middle-of-line (MOL) process parameters, (i.e. MOL thermal expense and mechanical stress from contact etch stop liner) on transistor performance and reliability. Based on the study, we have obtained device exhibit drive-current of 900/485 μA/μm for NMOSFET and PMOSFET, respectively, at standard supply voltage of 1 V.

Optical and Structural Characterization of Silicon Microstructures Fabricated by Laser Interference Crystallization

ABSTRACTUniform gratings of sharply defined polycrystalline silicon lines with micrometer-sized periods were created by laser interference crystallization of amorphous silicon. Atomic force microscopy (AFM) reveals that lines fabricated with high pulse energies (380 mJ/cm2) contain large grains (dimensions up to 1.5 μm), growing in a direction perpendicular to the lines. We assign this strong lateral growth to the melting of the material in the center of the lines combined with the presence of small grains, which act as nuclei, at the interfaces with the amorphous regions. Spatially resolved Raman spectroscopy shows that size effects dominate the Raman line shape at the edge of the line, confirming the AFM results, while stress increases towards the center of the line. The spectra measured in the middle of lines created with high energies show doping effects caused by the diffusion of boron atoms from the substrate upon exposure.

Language adaptation Edited by Florian Coulmas (review)

BOOK NOTICES 393 Part 2, 'The ontological question', considers in more detail the ontological implications of the view discussed in Part 1 . One chapter contrasts Cs proposal with certain varieties of materialism , reductionism, and dualism, as well as token physicalism. Another chapter treats views that regard linguistic objects as social realities of some kind. The final chapter discusses, among other things, the Platonism of Jerrold Katz. Cs proposals are not convincing. As he notes (125-6), the sentence/utterance distinction is central to his view, reflecting a fundamental ontological divide. Yet, utterances must take their form from the 'intersubjective' entities he takes sentences to be. Thus, when fully elaborated, his framework must provide some realization of the sentence and other linguistic objects in individual psychology; it becomes unclear what is achieved by adopting Cs ontology. Linguistic research might adopt as its proper focus the psychological manifestations of his intersubjective realities. A further problem is that C nowhere explains why. if sentences are intersubjective realities, the prospect of intersubjective comparison or integration never comes up; his view is that rules exist only insofar as they express generalizations that are true of some group of individuals . How is it then that, even adopting Cs ontology, we would never be moved to ask whether some group of individuals actually agrees on the properties of a given sentence? Of course, if C were to agree that systematic (perhaps experimental) comparisons across individuals had some role to play in establishing the nature of the intersubjective realities he posits , then the methodological divide he sees between linguistics and more typical scientific enterprises would collapse, at least in principle. But it is exactly that divide that he sets out to explain. Cs book has a place among the readings in a graduate course in the philosophy of linguistics . The methodological contrast from which he begins has been a continuing source of confusion , and this work can help to focus discussion aimed at uncovering its sources and implications. [Wayne Cowart. University of Southern Maine.) Readings in translation theory. Ed. by Andrew Chesterman. Helsinki: Oy Finn Lectura Ab, 1989. Pp. 200. This book might have made a good textbook for a course in translation theory; unfortunately, it is not one. Only one point comes across clearly in this anthology, namely, that good translation is hard work. The unsatisfactoriness of this collection of papers cannot be attributed to the various authors, among whom are John Dryden on 'Metaphrase , paraphrase, and imitation' (7-12), Roman Jakobson with 'On linguistic aspects of translation' (53-60), J. C. Catford on 'Translation shifts' (70-9), and Eugene A. Nida on 'Science of translation' (81-98). The book's shortcomings are primarily due to the editing. Chesterman's selections are too brief to convey any well-reasoned point: the average length of the sixteen articles here is under twelve pages. (Actually, it is little more than ten, if one discounts the editor's introduction for each paper.) No depth of thought on the involved subject of translation can be developed in so little space. Worse still, a number of the selections were not written to stand independently as they do here; the editor lifted them out of the middle of longer works. Chesterman does provide just enough background to make these articles almost comprehensible on their own, but the reader still aches to understand the authors' full contexts. The psychological effect of reading through this book is that of walking into a university building and standing by the door of each classroom for only five minutes. Mechanical lapses in the editing mar the book as well: one finds throughout the use of the hyphen for the em-dash, noncompound words inexplicably hyphenated in the middle of lines, assorted typos, and a line dittography (9-10). The editor has translated a number of the articles from French and German for this allEnglish anthology. I cannot vouch for the translations , but they generally read smoothly and coherently. The editor intended this book to serve as an overall introduction to the field of translation theory (5); at best the reader will make an acquaintance with the names ofa handful of translation theorists. [Brian M. Sietsema, Meniam-Webster. Inc...

A Turkish-Khotanese Vocabulary

Among the unexpected discoveries from the treasure of Central Asian manusćripts found in Tun-huang is a manuscript now belonging to the Fonds Pelliot in the Bibliothèque Nationale, numbered P 2892. This manuscript contains 184 lines of text in the cursive Brahmi script usual in Khotanese manuscripts. In lines 1–165 (mid-line) is written an excerpt in Khotanese from the medical text Siddhasāra corresponding to 5 v 4—14 v 4 of the Siddhāsara published in facsimile in Codices Khotanenses (1938), of which a transliterated text has been in print since December, 1941, in Khotanese Texts I. From the middle of line 165, after an elaborate mark of punctuation, there follow 19 lines of text in a Turkish dialect. It contains a vocabulary of ninety-seven Turkish words concerned with archery and parts of the body. Some of the words are glossed in Khotanese, and for some of these words the Turkish supplies the meaning. The date of the vocabulary may be the ninth or tenth century A.D. It would appear to be written down by a Khotanese scribe who wanted to learn Turkish.

Doppler Effect of Nuclear Resonance Level

EXPERIMENTAL and theoretical work has shown the existence of remarkably narrow resonance levels for the absorption of slow neutrons in certain nuclei1–5. In the cases of rhodium, silver (group A) and gold, the natural half-value width can be estimated as 0·06 volt, 0·05 volt and 0·12 volt, respectively. These values, however, may include errors of the order of 100 per cent. It has been pointed out by Frisch5 that these widths are comparable with the Doppler width which such resonance must show in consequence of the thermal agitation of the capturing nuclei. According to Bethe and Placzek3, the Doppler width is Er being the resonance energy and M the mass of the nucleus. This leads to the following widths at room temperature: 0·07 volt for rhodium, 0·1 volt for silver, 0·12 volt for gold. In the case of silver, the Doppler width seems to be even greater than the natural width. In this case, heating a silver absorber should influence considerably the absorption in the middle of the resonance line. In consequence of the Doppler broadening, the absorption in the middle of the line should decrease with increasing temperature of the absorber. Therefore this effect should be observed with a thin detector, which is sensitive principally to the middle of the line.

On the Estimation of the Middle of Lines

On the Estimation of the Middle of Lines