Thin Coverage Research Articles

The source of the high heat and freshwater content of the upper ocean at the SHEBA site in the Beaufort Sea in 1997

Measurements of 7Be and oxygen isotope (18O/16O) ratios from the 1997–1998 SHEBA experiment were used to trace the source of the high heat and freshwater content of the upper ocean observed during the initial occupation of the SHEBA site in October 1997. The evidence suggests that the heating resulted from local input primarily through extended lead coverage in the late spring and summer of 1997 with no requirement of advective input. The freshening was derived from a large ice melt (1.2 m) that was consistent with the thin ice and extensive melt pond coverage (by then frozen) observed at the site. However, a significant contribution to the freshwater budget (0.8 m) included enhanced input from river runoff during the melt season. This obviates the requirement for an unrealistically large ice melt (∼2 m) to account for the freshwater content of the mixed layer, and would have increased the stratification stability of the upper ocean that in turn would have promoted local heating. The question then arises, however, as to the fate of the significant upper ocean heat at SHEBA in the fall 1997 which resulted from an active heating season. Similar evaluation of the fall 1998 SHEBA site indicate that the ice melt was comparable to that of 1997, but the riverine input and stored water column heat were less than in the previous year.

Microscopic study of ultra-thin gold layers on polyethyleneterephthalate

Continuous and discontinuous gold layers sputtered on polyethyleneterephthalate (PET) were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM) and by reflection of microwave radiation. The changes in the surface morphology of the continuous and discontinuous gold layers as a function of the sputtering time were clearly observed by AFM technique. SEM imaging of very thin gold layers was adversely affected by specimen charging. For medium sputtering times, when a continuous gold coverage is already formed, the SEM technique still show the presence of regions with very thin gold coverage which gradually disappear at longer sputtering times. Both, the AFM and SEM techniques confirmed that in the course of the gold deposition the initially small gold clusters grow and finally associate in a continuous layer. It was shown that the sub-microne metallic structures could be modeled by artificial, significantly larger structures prepared on PET by lithographic etching.

Effect of liner thickness on electromigration lifetime

Electromigration lifetime was measured as a function of liner thickness for Cu/SiO2 interconnect structures. A significant increase in mean lifetime was observed for structures in which the liner thickness at the base of the test via was less than approximately 6 nm, with a current density <5 mA/μm2 in the power line connected to the test via. This is attributed to the continuous flow of Cu across the thin and possibly discontinuous liner at the base of the via. For extremely thin liner coverage, <1.4 nm at the base of the via and 2.5 at the bottom of the test line, the mean lifetime was observed to decrease as a rapid diffusion path was created which partially offset the beneficial effects of continuous flow. Failure distributions appeared to be trimodal and this was confirmed through failure analysis. In the case of thin liner coverage (<6 nm), early fails, which are typically characterized by slitlike voids at the via/line interface, were not observed.

Low-temperature selective epitaxy of silicon with chlorinated chemistry by RTCVD

Low-temperature epitaxial depositions are greatly attractive in the way of device fabrication, in order to improve electrical performances of advanced complementary metal oxide semiconductor (CMOS) and BiCMOS technologies. They present, however, some important difficulties such as a very high sensitivity to temperature and complex loading effects. In this paper, we investigate the selective epitaxy of silicon based on the dichlorosilane (DCS)/HCl/H 2 chemistry using an industrial 200-mm single wafer chemical vapour deposition at reduced pressure (<40 Torr) and low temperature (700–900 °C). First, we use a new evaluation procedure of the selectivity of Si epitaxy processes on thin nitride and oxide blanket coverage wafers with very low nuclei density counted with a surfscan. We evaluate the effects of intrinsic parameters of deposition such as HCl partial pressure and a parameter rarely reported in the literature: the duration of processes. Then we present results about global loading effects of Si growth within the DCS/H 2 system and of Si etch within the HCl/H 2 system. This allows us to anticipate and to give a new interpretation of the DCS/HCl/H 2 system loading effects. Special attention has been taken in order to eliminate the thermal contribution of different substrates and only chemical loading effects are reported. These studies are relevant to the fabrication of elevated source and drain, which have been integrated in an industrial CMOS technology.

Medicare Prescription Coverage and Congressional Gridlock: Time for Compromise

Medicare Prescription Coverage and Congressional Gridlock: Time for Compromise

The Finno-Ugric Republic and the Russian State by Rein s&gt; Taagepera (review)

REVIEWS I85 period of I985-91 makes this part of the book somewhat galling for a reader looking for a concise overviewof perestroikain Ukraine. Although the concept of 'resurgence'featuresin the title, it is never defined. The use of the term seems to denote the willingnessof the oppressednation to rise to the challenges of dismantling imperial shackles and consolidating independence. The book restson the implicit,and yet contentious, premise of Ukrainians being a ready-made nation, which, despite being the largest in Europe, 'has been denied the right to self-determination'(p. xi) until i99i. This premise prevents the author from examining the complex interplay of social, culturaland political processes in Soviet Ukraine, which produced an array of motives, attitudes and views regarding 'national revival' and independence in the masses and elites and in differentregions both prior to and after the passage to independence. While tracing the manifestations of 'resurgence', Nahaylo focuses on the cultural intelligentsia, political eites, Western Ukraine and Kyiv but glosses over the patchy nature of mass mobilization;in particularthe Russophone regions of Ukraine are given thin coverage. Therefore, the book falls short of advancing the understandingof the intricate nature of the Soviet period in Ukraine's history, which, on the one hand, created the pre-conditions for Ukraine's independence, while, on the other,drainednationalismof itsvitality. Overall, the book contains an unmatched amount of factual information, which fully demonstrates the author's impressive knowledge of recent developments in Ukraine. But while the book offersmany intricatedetails in itsaccount of the sixyearsprecedingthe referendumon independence, it does not depart from the interpretationsprovided by an existing survey of the period by Taras Kuzio and Andrew Wilson Ukraine. Perestroika toIndependence (Macmillan, 1994 and I999). The all-encompassingscope of the book makes it appear attractive to a wide audience. However, the exhaustive, 340-page description of perestroika in Ukraine will appeal to an astute student of Ukrainianpoliticsratherthan a readerlookingfor a 'concise modern political history'of Ukraine. Centrefor Russian andEastEuropean Studies K. WOLCZUK University ofBirmingham Taagepera, Rein. TheFinno-Ugric Republics and theRussianState.Hurst and Company, London, I999. xiii ? 449pp. Figures. Tables. Appendix. Bibliography.Index. [39.50. WITH the United Nations declaring the years 1995-2004 the 'Decade of Indigenous Peoples', the threshold of the new millennium is an historically appropriate juncture to consider the past, present and future of the 'threatened'peoples of the planet. While some twenty-five million Russians resident outside the Russian Federationhave been generally recognized as a geopoliticallydestabilizing'unexpected diaspora'of unprecedentedscale, the presence of some twenty-five million non-Russians within the Russian Federation has with the sensational exception of the Chechens been accorded little but statutoryacknowledgement.A principalobjective of Rein i86 SEER, 79, I, 2001 Taagepera's near-comprehensive new handbook is to publicize the FinnoUgric diasporawhich constitutesrathermore than three million of the latter non-Russianpopulation. Claiming to be the firstpost-Soviet generalworkon the Finno-Ugric peoples within the Russian Federation,the book is intended as a double-update, both exposing the grim realities of the pre-iggi Soviet ordeal and chronicling the ambivalent developments of the early and mid I99Os. Although a dedicated early chapter considers the 'Western FinnoUgric Nations' of Hungary, Finland and Estonia, all the remaining chapters are concerned with the various geopolitically-defined 'Eastern Finno-Ugric Nations' constitutionallyrecognized by the Russian Federation.Each of these chapterstargetsan individualnationalrepublic,emphasizingtheirdifferences by the addition of intriguing sub-titles. For example, chapter six is entitled 'Mariel: Europe'sLastAnimists'and chapterseven 'Udmurtia:The Redheacl Children of the Sun'. Each chapter follows a common topical format, considering(intypicalorder)history,languageandculture,religion,literature, geography and economy, demography, education, current issues and future perspectives. By thereby facilitating cross-referencingcomparison between the individual nations and republics, and also supplying abundant textual maps and statistical tables together with an exhaustive bibliography and index, Taagepera provides an invaluable mini-encyclopedia of the FinnoUgric diasporain Russiaforthe new millennium. What prospectsthat new millenniummay hold for the easternFinno-Ugric family is the paramount issue which is implicit throughout the descriptive chaptersand explicitin the firstchapteron 'The Finno-UgricRepublicsin the World Context' and the final chapter on 'Finno-Ugric Republics and the Future of Russian Democracy'. Taagepera is surely right to draw parallels with other 'threatenedpeoples' in the widerworld...

The Ukrainian Resurgence by Bohdan s&gt; Nahaylo (review)

i84 SEER, 79, I, 2001 in most cases it is quite well informed, and the bibliographyitself is synoptic and well-presented. Department ofPolitical Science ELLENT. CoMIsso University ofCalifornia, SanDiego Nahaylo, Bohdan. The Ukrainian Resurgence. Hurst and Company, London, I999. xix + 554 pp. Bibliography. Index. Maps. Illustrations. ?450.o; ? I6.95. DESPITE a recent upsurge in the number of publications on contemporary Ukraine, books on the subject are still few and far between. Hence any new publication is a welcome addition. Written in a genre of journalism and contemporaryhistory,in the author'sown words TheUkrainian Resurgence aims to 'serveas a surrogateconcise politicalhistoryof modern Ukraine and offera tentativepictureof the new independent Ukrainianstate'(p. xvi). The firstchapter concisely sketchesout the firstten centuries of Ukraine's history. The scope of the second chapter is considerablynarrower;focusing on the post-Stalin years in Ukraine, it contains a detailed survey of national Communism, dissident movement and their suppression by Moscow and indigenous Communists. Of the remaining sixteen chapters, no fewer than eleven aredevoted to perestroika'seventfulyearsof I985-9 I, whereasthe last four chaptersoffera comprehensive, although succinct, overview of developments in post-Soviet Ukraine between I992-96. The brief postscriptbrings the narrativeupto I998. The bookoffersa self-containednarrative,something which is also reflected in the brevity of the bibliography. Nahaylo does not engage with existing literatureon Ukraine, nor does he attempt to place the trajectoryof Ukraine'sstate-buildinginto a widercomparativeperspective. The book meticulously chronicles the prolonged struggle for, at first, nationalrevivaland, then, independence and scrupulouslyrecordsmanifestations of the 'indomitable spirit of patriotism' in Ukraine. It abounds with insightful accounts of the activities of the dissidents and the cultural intelligentsia,aswell aspoliticalelites.Inparticular,interviewswithCommunist dignitariesin Soviet Ukraine shed some welcome light on the functioning of the highest echelon of the Ukrainian nomenklatura.Forexample, Volodymyr Shcherbytskyi, the first secretary of Ukraine between 1972-89, was portrayed by his contemporaries as a 'very capable politician and administrator ',who, despite his well known subservienceto Moscow and hostilityto national revival in Ukraine, promoted Ukraine's economic development (PP. 50-5I')The book provides a comprehensivesurveyof all developments which can be broadlyclassifiedas manifestationsof 'nationalresurgence',whetherthese manifestationswere in the cultural,religious,political or economic domains. This is by any standards an ambitious task. Such broad coverage is only achieved by putting a premium on factual description, and hence the balance between the descriptive and analytical is skewed in favour of the former. The chronological organization of the factual material works for the more succinct chapters, but the wealth of graphic details in the eleven chapters covering the REVIEWS I85 period of I985-91 makes this part of the book somewhat galling for a reader looking for a concise overviewof perestroikain Ukraine. Although the concept of 'resurgence'featuresin the title, it is never defined. The use of the term seems to denote the willingnessof the oppressednation to rise to the challenges of dismantling imperial shackles and consolidating independence. The book restson the implicit,and yet contentious, premise of Ukrainians being a ready-made nation, which, despite being the largest in Europe, 'has been denied the right to self-determination'(p. xi) until i99i. This premise prevents the author from examining the complex interplay of social, culturaland political processes in Soviet Ukraine, which produced an array of motives, attitudes and views regarding 'national revival' and independence in the masses and elites and in differentregions both prior to and after the passage to independence. While tracing the manifestations of 'resurgence', Nahaylo focuses on the cultural intelligentsia, political eites, Western Ukraine and Kyiv but glosses over the patchy nature of mass mobilization;in particularthe Russophone regions of Ukraine are given thin coverage. Therefore, the book falls short of advancing the understandingof the intricate nature of the Soviet period in Ukraine's history, which, on the one hand, created the pre-conditions for Ukraine's independence, while, on the other,drainednationalismof itsvitality. Overall, the book contains an unmatched amount of factual information, which fully demonstrates the author's impressive knowledge of recent developments in Ukraine. But while the book offersmany intricatedetails in itsaccount of the sixyearsprecedingthe referendumon independence, it does not depart from the interpretationsprovided by an existing survey of the period by Taras Kuzio and Andrew Wilson Ukraine. Perestroika toIndependence...

Exposure of high-density porous polyethylene (Medpor®) used for contour restoration and treatment

Porous high-density polyethylene (Medpor®) is a biocompatible large-pore, high-density polyethylene implant. It is well tolerated by surrounding tissue, and its porous structure is rapidly infiltrated by host tissue. It is a highly stable and somewhat flexible porous alloplast that has rapid tissue ingrowth into its pores. However, when the implant is placed under a thin cover of skin, there is a risk of exposure. A total of 52 Medpor implants were placed in 31 patients over a four-year period. The implants were used for the chin, malar area, nasal reconstruction, ear reconstruction, orbital reconstruction, and the correction of mandibular contour deformities. Many of these implants were placed in areas considered problematic, such as those with thin or atrophic soft-tissue coverage and extensive scarring. There were nine complications, including three patients in whom the implant was exposed; these are presented here.

Studies of full color field emission display core technologies with the electrical and structural analysis

Electron beam spreading and its relationship with layout of field emission display (FED) is simulated and discussed. The morphological optimization of microtips is introduced for the effect of field enhancement with the process condition. The structural effect of thin film step coverage which is formed during the fabrication of field emitter arrays (FEAs) is uniquely studied with the reliability of FED. The surface condition of phosphor and its relationship with the brightness enhancement are analyzed and studied with the specific aging step. A unique approach of gas aging for the image stabilization is introduced and fully analyzed.

Lunar meteorite Queen Alexandra Range 94281: Glass compositions and other evidence for launch pairing with Yamato 793274

Abstract— Lunar meteorite Queen Alexandra Range 94281 is remarkably similar to Yamato 793274. Pairing in the conventional Earth‐entry sense is difficult to reconcile with the 2500 km separation between the find locations for these two samples. Nonetheless, both of these regolith breccias are dominated by very‐low‐Ti (VLT) mare basalt, the pyroxenes of which feature exsolution lamellae on a remarkably coarse scale (typical lamella width = 0.5–1 μm) by mare standards. The pyroxenes also show similar compositional variations (e.g., Fe# vs. Ti# trends, which confirm parentage from VLT mare basalt). Plots using Al2O3 or FeO as a tracer of the highland component indicate indistinguishable internal mare‐highland geochemical mixing trends. The same two distinctive glass types dominate the mare glass populations of both breccias. Glass type YQ1 features 0.37–0.63 wt% TiO2, 10–17 wt% MgO, and 9–11 wt% Al2O3. Glass type YQ2 features higher TiO2 (0.99–1.22 wt%), which is inversely correlated with MgO (12.6–13.8 wt%), and nearly constant (8.8 wt%) Al2O3. All of these similarities suggest that Y‐793274 and QUE 94281 are a launch pair, which we designate YQ. Most of these similarities also extend to another mare‐breccia meteorite, Elephant Moraine 87521. However, the EET 87521 mare basalt is unusually V‐poor (∼88 μg/g), whereas the YQ mare component contains ∼166 μg/g. Queen Alexandra Range 94281 features a variety of textural domains. Discrete patches of dark matrix material appear to represent clods of mature regolith that have been mixed with a coarser, relatively immature material. Interior to a frothy fusion crust are areas of massive glass that probably formed as a splash coating on QUE 94281 when it was still on the Moon. The coarse YQ and EET 87521 pyroxene exsolution features imply relatively slow cooling in either a very shallow sill or an unusually thick (ponded) lava and/or later annealing within a cryptomare.Mare pyroclastic glasses, including the two YQ varieties, are systematically MgO‐rich compared to crystalline mare basalts. This disparity may be a consequence of limited survival of graphite—the main fuel for explosive volcanism—during formation of the mare source regions as magma ocean cumulates. Graphite (2.2 g/cm3) survived preferentially in regions that avoided extensive early melting and thus remained MgO‐rich. An apparent bimodality in the TiO2 contents of mare volcanics, especially the pyroclastic glasses, also seems a plausible consequence of petrogenesis by remelting of magma ocean cumulates. Cumulates deposited after the magma ocean evolved to ilmenite saturation had vastly higher TiO2 contents than cumulates deposited shortly before. The YQ regolith's subequal proportions of mare and highland matter are consistent with derivation from a terrain close to a mare‐highland boundary. However, a similar mixture might also develop through vertical mixing in a cryptomare or a region of thin mare coverage. Thus, unfortunately, the YQ bulk composition is not a very useful clue to the identity of the source crater.

Self-aggregated InAs quantum dots in GaAs

We present a detailed study, both structural and optical, of GaAs/InAs/GaAs heterostructures for InAs nominal coverages (L) ranging from 0.6 to 3 ML. Planar transmission electron microscopy (TEM) provides direct evidence of the presence of InAs quantum dots (QDs) for all values of L, with an increase in their density at high values of L. Transverse TEM shows also that those QDs have mostly small base angles. Accordingly, the evolution of the optical properties of InAs/GaAs is investigated by photoluminescence (PL) and PL excitation measurements (PLE). A broad PL band is observed in all samples, which is ascribed to the recombination of heavy-hole excitons in the InAs quantum dots, observed with TEM. For thin coverages (L⩽1.6ML), a narrow PL band is also observed, which is attributed to recombination of heavy-hole excitons in a two-dimensional (2D) InAs layer. The two bands shift to lower energy for increasing L. For L⩾1.6 ML, the QD band has a faster shift and exhibits a complex structure, while the exciton recombination in the 2D-InAs layer vanishes. Those features, as well as the PLE results, indicate that: (a) quantum dots are connected by a two-dimensional InAs layer, at least for thin InAs coverages, which allows an efficient carrier capture into the dots; (b) the dot size increases with L, the increase being faster for L⩾1.6 ML because above this thickness the growth becomes completely three dimensional. A simple model explains the PL data and results in a dot geometry in agreement with the TEM measurements.

Intraosseous Plating

Biodegradable miniplates and screws offer special possibilities for surgical techniques because the removal operation is avoided. In areas beneath thin skin, intraosseous plating could be preferable to avoid palpability and transient swelling during resorption. The tissue reaction to a 0.5-mm-thick self-reinforced poly-L-lactide (SR-PLLA) plate fixed with an SR-PLLA miniscrew was studied histologically and histomorphometrically after implantation into the calvarium of six young sheep. After follow-up periods of 6, 20, and 52 weeks, no signs of adverse tissue reaction such as clinically manifest foreign body reaction or histologically manifest osteolysis were noted. By 52 weeks the implants were largely in direct contact with remodeled, dense bone tissue. No signs of fragmentation or resorption were noted in the intraosseous parts of the implants, whereas the screw head had been fragmented and was undergoing resorption at 52 weeks. The screw head is unnecessary in this plating method and could have been removed with a hot wire loop. The excellent biocompatibility of the mechanically strong, resorbable SR-PLLA plate with miniscrew fixation provides a possibility for intraosseous plating in less loaded craniofacial areas, especially in areas with very thin soft-tissue coverage.

Surface Morphological Study of J-Aggregate Thin Films by Atomic Force Microscopy

Surface Morphological Study of J-Aggregate Thin Films by Atomic Force Microscopy

Water on Salt: An Infrared Study of Adsorbed H2O on NaCl(100) under Ambient Conditions

Using infrared spectroscopy, we were able to determine that water, under ambient conditions, adsorbs onto the surface of NaCl(100) into a liquidlike thin film. Photometric methods allowed coverages to be monitored from near ϑ = 0.1 (0.1 monolayer) to ϑ = 3. The shifting band center of the −OH stretching region suggests changing hydrogen-bonding environments with coverage. In the submonolayer region, water−surface bonds are favored over water−water hydrogen bonds. Thin film coverages near ϑ = 2 produce spectra essentially indistinguishable from that of a saturated salt solution suggesting a liquidlike hydrogen-bonded network. This thin film can be reversibly removed from the NaCl(100) surface. However, at coverages near ϑ = 3, dissolution begins and the salt surface becomes visibly damaged. Isotherms measured at 12 and 24 °C allowed the determination of the isosteric heat of adsorption. This heat of adsorption for coverages near ϑ = 2 is close to that of the heat of condensation of liquid water, again suggesting that the thin film is liquidlike. A model for thin film water growth on NaCl(100) under ambient and cryogenic conditions is proposed.

Evolution of the Optical Properties of InAs/GaAs Quantum Dots for Increasing InAs Coverages

The photoluminescence (PL) of InAs/GaAs heterostructures is investigated for InAs coverages, L, ranging from 0.6 to 3 monolayers (ML). For thin coverages (L ≤ 1.6 ML), we observe the recombination of heavy-hole excitons in InAs quantum dots (QDs) and in a 2D-InAs layer. The two PL bands shift toward low energy for increasing L. For L ≤ 1.6 ML, the QD band shifts faster, while the exciton recombination in the 2D-layer vanishes. These results, confirmed by PL excitation and photoreflectivity, indicate that: a) QDs are interconnected by a two-dimensional InAs layer which allows an efficient carrier capture into the dots; b) the dot size increases with L, faster for L ≤ 1.6 ML, at the expense of the 2D-layer. The peculiar temperature dependence of lineshape and peak energy of the QD band is explained in terms of exciton thermal escape and relaxation mechanisms.

Vapor Phase Self-Assembly of Fluorinated Monolayers on Silicon and Germanium Oxide

Molecular orientation in monomolecular thin organic films and surface coverage on Ge/Si oxide was measured by attenuated total reflectance Fourier transform infrared spectroscopy. A gas phase reactor allowed for precise control of surface hydration and reaction temperature during the deposition of monofunctional perfluorated alkylsilanes. It is therefore considered superior to solution-based silylation procedures commonly employed.

Island adipofascial flap for resurfacing of the Achilles tendon.

Satisfactory replacement of soft-tissue defects over the Achilles tendon remains a difficult challenge for plastic surgeons. Flap coverage is vital to preserve an exposed tendon as well as to supply a gliding surface. Ten patients were selected for this study who had sustained exposed Achilles tendons either after trauma or after excision of burn scar. The island adipofascial flap was used based on the most distal two to three septocutaneous perforators of the posterior tibial artery that are located 3.7 to 5.5 cm proximal to the tip of the medial malleolus, as confirmed by my anatomic study. The island adipofascial flap provides a durable and thin coverage for the Achilles tendon, as well as a good vascularized bed for skin grafting.

Consideration of a Thin Flap as an Entity and Clinical Applications of the Thin Anterolateral Thigh Flap

A defatted (thinned) anterolateral thigh flap was designed to reconstruct skin defects requiring thin flap coverage. We used this flap as a free flap for five cases of skin defects, and the outcomes of the reconstructions were all successful. The vascular pedicle of this flap, the cutaneous perforator of the lateral circumflex femoral artery, is about 8 cm long and 2 mm in diameter, and it is ideal for microvascular anastomosis. Thinning is performed in about 3 to 4 mm of thickness almost uniformly except for the vascular pedicle. It was ascertained as one of the useful donor sites of the free thin flap. The virtue of the thin anterolateral thigh flap is its uniform thinness compared with other thin flaps reported previously--the thin groin flap and the thin rectus abdominis musculocutaneous flap. We considered thin flaps as an entity, and they are classified into three types.

Cs5p and 4d photoelectron linewidths of [formula omitted]: implication for CsRu interaction at the interface

Photoelectron linewidths of Cs5p and 4d levels of Cs adsorbed on Ru(001) for a series of coverages varying from submonolayer to multilayer have been examined. It is found that linewidth broadening for Cs atoms in direct contact with Ru occurs for both levels when compared with that of bulk Cs atoms, and that while Cs4d levels broaden slightly but persistently over the entire range of coverage, the 5p linewidth exhibits a sharp change between Cs atoms that are in direct contact with the Ru substrate and those that are not; that is at submonolayer, monolayer and thin multilayer coverage, the Cs5p peak of the Cs atoms which are in direct contact with the Ru substrate broadens considerably in comparison with the Cs5p peak of the Cs atoms in the second overlayer and in Cs metal. The Cs5p linewidth broadening is attributed primarily to the relatively short lifetime of the core hole resulting from a fast Coster-Kronig/super Coster-Kronig decay channel facilitated by CsRu interaction at the interface. This channel, which is absent in the primary decay of the Cs4d core hole, has little effect on the 4d linewidth. This Cs5p linewidth broadening appears to be general for Cs in direct contact with any metal substrate and is discussed in terms of a s-d charge redistribution (rehybridization) model with the assistance of relativistic Dirac-Fock calculations. The less dramatic Cs4d broadening is attributed to a combined effect of interfacial phonon, chemical inhomogeneity and crystal filed broadening.

Plasma anodic oxidation of semiinsulating GaAs

A technique is presented for the plasma anodic oxidation of semiinsulating (SI) GaAs surfaces at elevated sample temperatures (up to 230°C) the anodization current being fed vertically across the semiconductor. Capacitance and resistance measurements were performed on corresponding MOS structures for the determination of the lowest temperature at which the oxide growth can proceed. The oxide/SI-GaAs interface properties were investigated by correlation of DLTS, photoluminescence and X-ray reflectivity methods with the aim to better clarify the oxidation kinetics. Moreover, it was determined that the interface region seems to be better formed, being thinner, when a thin aluminium coverage layer is deposited on the SI-GaAs surface before the oxidation process. On the basis of our experimental results, we presume that each anodic oxidation process can be characterized by a cross section of the reaction of the oxygen ions with the semiconductor atoms due to the different oxidation state of the latter which is determined by given oxidation conditions. Its value for SI-GaAs sample at 230°C has been calculated to be ∼ 3.0 × 10 −14cm 2.