Characterizing the stress and electrical properties of superconducting molybdenum films

Abstract In the process of minimizing stress in sputtered Molybdenum (Mo) films for fabricating transition-edge sensor (TES) devices, we have investigated correlations between the stress and film deposition parameters. At a fixed sputtering power, the tensile stress of our film samples decreases toward both low and high ends of Ar pressure, suggestive of two physical mechanisms at work: an “atomic peening” effect at low Ar pressure and the development of voids at high Ar pressure. We have also carried out correlative studies of the stress and electrical properties (including superconducting critical temperature and residual resistivity) of the film samples, and found that the results are complex. We have made extensive comparisons with the published results, and attempted to explain the discrepancies in terms of film deposition techniques, sample preparation and treatment, and dynamical ranges of measurements. It is fairly clear that the microscopic properties, including porosity and disorder, of Mo films may have significant impact on the correlations.

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Tuning SPT-3G Transition-Edge-Sensor Electrical Properties with a Four-Layer Ti–Au–Ti–Au Thin-Film Stack

Journal of Low Temperature Physics ◽

10.1007/s10909-018-1910-7 ◽

2018 ◽

Vol 193 (5-6) ◽

pp. 695-702 ◽

Cited By ~ 9

Author(s):

F. W. Carter ◽

P. A. R. Ade ◽

Z. Ahmed ◽

A. J. Anderson ◽

J. E. Austermann ◽

...

Keyword(s):

Thin Film ◽

Electrical Properties ◽

Transition Edge Sensor ◽

Transition Edge ◽

Au Thin Film

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Electrical Behaviour of Langmuir Films: A Review, Part I

ElectroComponent Science and Technology ◽

10.1155/apec.2.1 ◽

1975 ◽

Vol 2 (1) ◽

pp. 1-31 ◽

Cited By ~ 29

Author(s):

V. K. Agarwal

Keyword(s):

Electrical Properties ◽

Electrical Breakdown ◽

Basic Research ◽

Film Deposition ◽

Langmuir Films ◽

Organic Films ◽

Electrical Behaviour ◽

Depth Of Knowledge ◽

Induced Changes ◽

Deposition Techniques

The electrical behaviour of thin films obtained by a variety of processes, e.g. thermal evaporation in vacuum, have been extensively studied. However, the study of organic mono- and multilayer films obtained by the Blodgett–Langmuir technique (commonly referred to as Langmuir films) has gained considerable momentum only during the past decades. Unlike evaporated films, the striking features of these organic films are their controllable thicknesses down to one monolayer (~ 25 Å) and the possibility of obtaining them free from holes and conducting imperfections. The aim of this paper is to describe the film deposition techniques, some of the properties of the films so obtained and to review their electrical behaviour. It is also intended to make this review a comprehensive and up-to-date source of information for those who are either already engaged in this field or are planning to make Langmuir films the subject for future investigations.In this survey, emphasis is put on problems worth further study to obtain greater insight into the basic properties of these films. Further, since they possess some interesting electrical properties, this paper may prove useful in the assessment of our depth of knowledge about them and in reducing the existing gap between basic research and technological applications. Thus their potential usefulness in the development of devices is also discussed.The survey is divided into two parts. Part I is concerned with deposition techniques, the physical properties of Langmuir films and certain electrical properties, namely dielectric behaviour and electrical conduction phenomena. Part II, which will appear in the next issue, will be concerned with electrical breakdown behaviour, voltage induced changes in electrical behaviour (forming) and ionic transport phenomena in the films and will finish with suggestions as to future trends in work with such films together with a summary of possible applications.To assist the reader, the two parts have been numbered consecutively with regard to sections of the text, figures and references.

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Electrical Behaviour of Langmuir Films: A Review, Part II

ElectroComponent Science and Technology ◽

10.1155/apec.2.75a ◽

1975 ◽

Vol 2 (2) ◽

pp. 75-107 ◽

Cited By ~ 14

Author(s):

V. K. Agarwal

Keyword(s):

Electrical Properties ◽

Electrical Breakdown ◽

Basic Research ◽

Film Deposition ◽

Langmuir Films ◽

Organic Films ◽

Electrical Behaviour ◽

Depth Of Knowledge ◽

Induced Changes ◽

Deposition Techniques

The electrical behaviour of thin films obtained by a variety of processes, e.g. thermal evaporation in vacuum, has been extensively studied. The study of organic mono- and multilayer films obtained by the Blodgett–Langmuir technique (commonly referred to as Langmuir films), however, has gained considerable momentum only during the past decades. Unlike evaporated films, the stiking features of these organic films are their controllable thicknesses down to one monolayer (~25 Å) and the possibility of obtaining them free from holes and conducting imperfections. The aim of this paper is to describe the film deposition techniques, some of the properties of the films so obtained and to review their electrical behaviour. It is also intended to make this review a comprehensive and up-to-date source of information for those who are either already engaged in this field or are planning to adopt Langmuir films for future investigations.In this survey, emphasis is put on the possible problems worth further study to get more insight into the basic properties of these films. Further, since the latter possess some interesting electrical properties, this paper may prove useful in the assessment of our depth of knowledge about them and in reducing the existing gap between basic research and technological applications. Their potential usefulness in developing devices is therefore also discussed.The survey has been divided into two parts. Part I was concerned with deposition techniques, the physical properties of Langmuir films and certain electrical properties, namely dielectric behaviour and electrical conduction phenomena. This second part is concerned with electrical breakdown behaviour, voltage induced changes in electrical behaviour (forming) and ionic transport phenomena in the films and finishes, with suggestions as to future trends in work with such films together with a summary of possible applications.To assist the reader, the two parts have been numbered consecutively with regard to sections of the text, figures and references. “Appropriate” references already cited in Part I are given again at the end of this part.

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Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089652 ◽

1991 ◽

Vol 49 ◽

pp. 1068-1069

Author(s):

M. Grant Norton ◽

C. Barry Carter

Keyword(s):

Thin Film ◽

Thin Films ◽

Laser Ablation ◽

Substrate Surface ◽

Pulsed Laser ◽

Pulsed Laser Ablation ◽

Thin Film Deposition ◽

Film Deposition ◽

Laser Ablation Process ◽

Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

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Excess Heat Capacity in Mo/Au Transition Edge Sensor Bolometric Detectors

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2021.3065922 ◽

2021 ◽

pp. 1-1

Author(s):

Ari David Brown ◽

Regis Brekosky ◽

Felipe Colazo-Petit ◽

Matthew Greenhouse ◽

James Hay-Wehle ◽

...

Keyword(s):

Heat Capacity ◽

Transition Edge Sensor ◽

Excess Heat Capacity ◽

Excess Heat ◽

Bolometric Detectors ◽

Transition Edge

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Germanium Nanowires as Sensing Devices: Modelization of Electrical Properties

Nanomaterials ◽

10.3390/nano11020507 ◽

2021 ◽

Vol 11 (2) ◽

pp. 507

Author(s):

Luca Seravalli ◽

Claudio Ferrari ◽

Matteo Bosi

Keyword(s):

Charge Transfer ◽

Electrical Properties ◽

Surface Charges ◽

Molecular Sensing ◽

Germanium Nanowires ◽

Physical Mechanisms ◽

Additional Doping ◽

Different Types ◽

N Doping ◽

Very High

In this paper, we model the electrical properties of germanium nanowires with a particular focus on physical mechanisms of electrical molecular sensing. We use the Tibercad software to solve the drift-diffusion equations in 3D and we validate the model against experimental data, considering a p-doped nanowire with surface traps. We simulate three different types of interactions: (1) Passivation of surface traps; (2) Additional surface charges; (3) Charge transfer from molecules to nanowires. By analyzing simulated I–V characteristics, we observe that: (i) the largest change in current occurs with negative charges on the surfaces; (ii) charge transfer provides relevant current changes only for very high values of additional doping; (iii) for certain values of additional n-doping ambipolar currents could be obtained. The results of these simulations highlight the complexity of the molecular sensing mechanism in nanowires, that depends not only on the NW parameters but also on the properties of the molecules. We expect that these findings will be valuable to extend the knowledge of molecular sensing by germanium nanowires, a fundamental step to develop novel sensors based on these nanostructures.

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Structural, Optical and Electrical Properties of Al+MoO3 and Au+MoO3 Thin Films Prepared by Magnetron Codeposition

Materials ◽

10.3390/ma14040766 ◽

2021 ◽

Vol 14 (4) ◽

pp. 766

Author(s):

Tihomir Car ◽

Ivan Jakovac ◽

Ivana Šarić ◽

Sigrid Bernstorff ◽

Maja Micetic

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Au Nanoparticle ◽

Content Increase ◽

Optical And Electrical Properties ◽

Volume Percentage ◽

Sputtering Deposition ◽

Nanoparticle Formation ◽

Al Content ◽

Sputtering Power

Structural, optical and electrical properties of Al+MoO3 and Au+MoO3 thin films prepared by simultaneous magnetron sputtering deposition were investigated. The influence of MoO3 sputtering power on the Al and Au nanoparticle formation and spatial distribution was explored. We demonstrated the formation of spatially arranged Au nanoparticles in the MoO3 matrix, while Al incorporates in the MoO3 matrix without nanoparticle formation. The dependence of the Au nanoparticle size and arrangement on the MoO3 sputtering power was established. The Al-based films show a decrease of overall absorption with an Al content increase, while the Au-based films have the opposite trend. The transport properties of the investigated films also are completely different. The resistivity of the Al-based films increases with the Al content, while it decreases with the Au content increase. The reason is a different transport mechanism that occurs in the films due to their different structural properties. The choice of the incorporated material (Al or Au) and its volume percentage in the MoO3 matrix enables the design of materials with desirable optical and electrical characteristics for a variety of applications.

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