Chromatic Change in Copper Oxide Layers Irradiated with Low Energy Ions

The color of a thin copper oxide layer formed on a copper plate was transformed from reddish-brown into blue-purple by irradiation with 5 keV Ar+ ions to a fluence as low as 1 1015 Ar+ cm–2. In the unirradiated copper oxide layer, the copper valence state of Cu2+ as well as Cu+ and/or Cu0 was included as indicated by the presence of a shake-up satellite line in a photoemission spectrum. While for the irradiated one, the satellite line decreased in intensity, indicating that irradiation resulted in the reduction from Cu2+ to Cu+ and/or Cu0. Furthermore, nuclear reaction analysis using a 16O(d, p)17O reaction with 0.85 MeV deuterons revealed a significant loss of oxygen (51015 O atoms cm–2) in the irradiated layer. Thus, the chromatic change observed in the present work originated in the irradiation-induced reduction of a copper oxide.

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Chromatic Change in Copper Oxide Layers Irradiated with Low Energy Ions

Quantum Beam Science ◽

10.3390/qubs5010007 ◽

2021 ◽

Vol 5 (1) ◽

pp. 7

Author(s):

Takuya Kobayashi ◽

Fumitaka Nishiyama ◽

Katsumi Takahiro

Keyword(s):

Copper Oxide ◽

Oxide Layer ◽

Significant Loss ◽

Copper Plate ◽

Nuclear Reaction Analysis ◽

Photoemission Spectrum ◽

Satellite Line ◽

Copper Valence ◽

Low Energy Ions ◽

Dark Blue

The color of a thin copper oxide layer formed on a copper plate was transformed from reddish-brown into dark blue-purple by irradiation with 5 keV Ar+ ions to a fluence as low as 1 × 1015 Ar+ cm−2. In the unirradiated copper oxide layer, the copper valence state of Cu2+ and Cu+ and/or Cu0 was included as indicated by the presence of a shake-up satellite line in a photoemission spectrum. While for the irradiated one, the satellite line decreased in intensity, indicating that irradiation resulted in the reduction from Cu2+ to Cu+ and/or Cu0. Furthermore, nuclear reaction analysis using a 16O(d, p)17O reaction with 0.85 MeV deuterons revealed a significant loss of oxygen (5 × 1015 O atoms cm−2) in the irradiated layer. Thus, the chromatic change observed in the present work originated in the irradiation-induced reduction of a copper oxide.

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Investigations on the Photoprotection Ability of TiO2 Coated on Copper

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.297 ◽

2005 ◽

Vol 475-479 ◽

pp. 297-300

Author(s):

Raghavan Subasri ◽

Tadashi Shinohara

Keyword(s):

Copper Oxide ◽

Oxide Layer ◽

Electrode Potential ◽

Prolonged Exposure ◽

Electrolyte Solutions ◽

Copper Plate ◽

Tio2 Coating ◽

Uv Illumination ◽

Photogenerated Electrons ◽

Ito Glass

A TiO2 coating when directly applied on copper plate showed an instantaneous ptype behavior, i.e. ennoblement of electrode potential on ultraviolet (UV) illumination though a copper plate when galvanically coupled to an ITO glass coated with TiO2 showed immediate lowering of electrode potential (‘n’-type effect) on illumination under deaerated conditions. The instantaneous p-type effect in the former case was attributed to the presence of a copper oxide layer present between the copper plate and the TiO2 coating. However, a prolonged exposure of the TiO2 coated copper plate showed an n-type effect under illumination after nearly 24 h, following which the electrode potential appeared stable and highly negative. This observation indicated that the photogenerated electrons in TiO2 are capable of reducing the copper oxide layer to ultimately realize the n-type effect of TiO2. The n-type effect could not be observed in aerated electrolyte solutions. The effect of different conditions in the ambience on the photoeffect of copper coated TiO2 will be discussed.

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The theory of crystal rectifiers

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1939.0051 ◽

1939 ◽

Vol 171 (944) ◽

pp. 27-38 ◽

Cited By ~ 321

Keyword(s):

Copper Oxide ◽

Oxide Layer ◽

Cuprous Oxide ◽

Copper Plate ◽

Significant Part ◽

Lead Plate

It has long been known that the contact between a metal and a semiconductor has a resistance which varies, in many cases considerably, with the direction of the current. A well-known example is the copper-cuprous oxide rectifier, which consists of a copper plate on which a layer of cuprous oxide has been formed, the oxide being in contact with a lead plate. It is the purpose of this paper to criticize existing theories of this effect and to suggest a new one. In any crystal rectifier we have two contacts to consider; for instance, in the copper-oxide rectifier there is the contact between the copper and the oxide, and that between the oxide and the lead. We may say at once that a condition for rectification is that at least one of these contacts shall have a resistance which is not small compared with the resistance of the oxide layer; for any theory will give, in the limit of small voltages across the contact, equal resistances in both directions; it is necessary that a significant part of the fall in potential in the rectifier should occur at the contact.

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An Effective SIMS Methodology for GOI Contamination Analysis

ISTFA 2013: Conference Proceedings from the 39th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2013p0427 ◽

2013 ◽

Author(s):

Yanhua Huang ◽

Lei Zhu ◽

Kenny Ong ◽

Hanwei Teo ◽

Younan Hua

Keyword(s):

Oxide Layer ◽

Secondary Ion Mass Spectrometry ◽

Gate Oxide ◽

Sample Surface ◽

Low Energy ◽

Cross Contamination ◽

Common Effect ◽

Sims Analysis ◽

Secondary Ion ◽

Lower Background

Abstract Contamination in the gate oxide layer is the most common effect which cause the gate oxide integrate (GOI) issue. Dynamic Secondary Ion Mass Spectrometry (SIMS) is a mature tool for GOI contamination analysis. During the sample preparation, all metal and IDL layers above poly should be removed because the presence of these layers added complexity for the subsequent SIMS analysis. The normal delayering process is simply carried out by soaking the sample in the HF solution. However, the poly surface is inevitably contaminated by surroundings even though it is already a practice to clean with DI rinse and tape. In this article, TOFSIMS with low energy sputter gun is used to clean the sample surface after the normal delayering process. The residue signals also can be monitored by TOF SIMS during sputtering to confirm the cross contamination is cleared. After that, a much lower background desirable by dynamic SIMS. Thus an accurate depth profile in gate oxide layer can be achieved without the interference from surface.

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Analysis of Experimental Data for Neutralization of Low-Energy Ions at a Solid Surface.

10.21236/ada163205 ◽

1986 ◽

Author(s):

Hai-Woong Lee ◽

Thomas F. George

Keyword(s):

Experimental Data ◽

Solid Surface ◽

Low Energy ◽

Low Energy Ions

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Ion-Assisted Surface Processing of Electronic Materials

MRS Bulletin ◽

10.1557/s0883769400041476 ◽

1992 ◽

Vol 17 (6) ◽

pp. 52-57 ◽

Cited By ~ 6

Author(s):

S.T. Picraux ◽

E. Chason ◽

T.M. Mayer

Keyword(s):

Plasma Etching ◽

Electronic Materials ◽

Low Energy ◽

Surface Processing ◽

Wave Guides ◽

Side Walls ◽

Wet Chemical ◽

Low Energy Ions ◽

Metal Layers ◽

Defect Densities

Why are low-energy ions relevant to the surface processing of electronic materials? The answer lies in the overriding trend of miniaturization in microelectronics. The achievement of these feats in ultrasmall architecture has required surface processing capabilities that allow layer addition and removal with incredible precision. The resulting benefits of greater capacity and speed at a plummeting cost per function are near legendary.The ability of low-energy ions to enhance the precision of surface etching, cleaning, and deposition/growth processes (Figure 1) provides one basis for the interest in ion-assisted processes. Low-energy ions are used, for example, to enhance the sharpness of side walls in plasma etching and to improve step coverage by metal layers in sputter deposition. Emerging optoelectronic applications such as forming ridges for wave-guides and ultrasmooth vertical surfaces for lasers further extend piesent requirements, and low-energy ions again provide one tool to help in this area of ultraprecise materials control. Trends associated with the decreased feature size include the movement from wet chemical processing to dry processing, the continuing need for reductions in defect densities, and the drive toward reduced temperatures and times in process steps.How do the above trends focus interest on studies of low-energy ion-assisted processes? In current applications, these trends are driving the need for increased atomic-level understanding of the ion-enhancement mechanisms, for example, in reactive ion etching to minimize defect production and enhance surface chemical reactions.

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Modelling Interaction Cross Sections for Intermediate and Low Energy Ions

Radiation Protection Dosimetry ◽

10.1093/oxfordjournals.rpd.a006837 ◽

2002 ◽

Vol 99 (1) ◽

pp. 49-51 ◽

Cited By ~ 1

Author(s):

L. H. Toburen ◽

J. L. Shinpaugh ◽

E. L. B. Justiniano

Keyword(s):

Cross Sections ◽

Low Energy ◽

Low Energy Ions ◽

Interaction Cross Sections

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Epitaxy and Chemical Reactions During Thin Film Formation from Low Energy Ions New Kinetic Pathways, New Phases and New Properties

MRS Proceedings ◽

10.1557/proc-236-287 ◽

1991 ◽

Vol 236 ◽

Cited By ~ 1

Author(s):

Nicole Herbots ◽

O.C. Hellman ◽

O. Vancauwenberghe

Keyword(s):

Thin Film ◽

Chemical Reactions ◽

Degrees Of Freedom ◽

Film Growth ◽

Film Formation ◽

Chemical Reactivity ◽

Ion Beam ◽

Low Energy ◽

Low Energy Ions ◽

Beam Deposition

AbstractThree important effects of low energy direct Ion Beam Deposition (IBD) are the athermal incorporation of material into a substrate, the enhancement of atomic mobility in the subsurface, and the modification of growth kinetics it creates. All lead to a significant lowering of the temperature necessary to induce epitaxial growth and chemical reactions. The fundamental understanding and new applications of low temperature kinetics induced by low energy ions in thin film growth and surface processing of semiconductors are reviewed. It is shown that the mechanism of IBD growth can be understood and computed quantitatively using a simple model including ion induced defect generation and sputtering, elastic recombination, thermal diffusion, chemical reactivity, and desorption The energy, temperature and dose dependence of growth rate, epitaxy, and chemical reaction during IBD is found to be controlled by the net recombination rate of interstitials at the surface in the case of epitaxy and unreacted films, and by the balance between ion beam decomposition and phase formation induced by ion beam generated defects in the case of compound thin films. Recent systematic experiments on the formation of oxides and nitrides on Si, Ge/Si(100), heteroepitaxial SixGe1−x/Si(100) and GaAs(100) illustrate applications of this mechanism using IBD in the form of Ion Beam Nitridation (IBN), Ion Beam Oxidation (IBO) and Combined Ion and Molecular beam Deposition (CIMD). It is shown that these techniques enable (1) the formation of conventional phases in conditions never used before, (2) the control and creation of properties via new degrees of freedom such as ion energy and lowered substrate temperatures, and (3) the formation of new metastable heterostructures that cannot be grown by pure thermal means.

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