On the residual stress developed in the nanostructure of computer simulated thin films

Jalali-Jafari, Behdad; Savaloni, Hadi; Shahraki, Mehran Gholipour

doi:10.1002/pssb.200642199

Cited by 3 publications

(11 citation statements)

References 36 publications

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“…III-A). Furthermore, while we do indeed observe fairly significant changes in the film rate of deposition, McCaughey 37 and Jalali-Jafari 24 have both demonstrated through molecular dynamics simulations that decreasing film deposition rate is shown to have either no effect, or to actually increase the inherent void creation, and conclude (as we assert here) that it is ion impact effects causing the observed decline in void concentration with increasing deposition rate (which we capture in the isolated compressive stress component model). Finally, we have measured surface roughness by atomic force microscopy (AFM), which shows no correlation to deposition conditions, further assuring us that the surface evolution is not being substantially altered by changes to the process pressure.…”

Section: Void Collapse Effects On Stresssupporting

confidence: 47%

“…Intrinsic stress in amorphous silicon thin films can be viewed as a balance between two distinct but competing forces: the collapse of hydrogenated nanovoids after being formed on the depositing layer creating tensile stress, 24,25 and lattice expansion effects, which are responsible for the creation of compressive stresses in the film through the implantation of ions into the previously deposited layers 26 (often referred to as "ion peening"). While plasma ion momentum dictates both of these forces, it is their relative strength at any given momentum level that determines the net intrinsic stress state of the film.…”

Section: A Origins Of Stressmentioning

confidence: 99%

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Structural origins of intrinsic stress in amorphous silicon thin films

et al. 2012

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Hydrogenated amorphous silicon (a-Si:H) refers to a broad class of atomic configurations, sharing a lack of long-range order, but varying significantly in material properties including optical constants, porosity, hydrogen content, and intrinsic stress. It has long been known that deposition conditions affect microstructure, but much work remains to uncover the correlation between these parameters and their influence on electrical, mechanical, and optical properties critical for high-performance a-Si:H photovoltaic devices. We synthesize and augment several previous models of deposition phenomena and ion bombardment, developing a refined model correlating plasma enhanced chemical vapor deposition (PECVD) conditions (pressure and discharge power and frequency) to the development of intrinsic stress in thin films. As predicted by the model presented herein, we observe that film compressive stress varies nearly linearly with bombarding ion momentum and with a (-1/4) power dependence on deposition pressure, that tensile stress is proportional to a reduction in film porosity, and the net film intrinsic stress results from a balance between these two forces. We observe the hydrogen bonding configuration to evolve with increasing ion momentum, shifting from a voiddominated configuration to a silicon monohydride configuration. Through this enhanced understanding of the structure-property-process relation of a-Si:H films, improved tunability of optical, mechanical, structural, and electronic properties should be achievable.

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Section: Void Collapse Effects On Stresssupporting

confidence: 47%

Section: A Origins Of Stressmentioning

confidence: 99%

Structural origins of intrinsic stress in amorphous silicon thin films

et al. 2012

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“…Similar to Refs. [12,13], we roughly estimated the rate of photon-assisted tunneling in SSET irradiated under the conditions of the resonant peak and the gate tuned to the sensitive point, n g ≈ −0.25. The obtained value, Γ ph ∼ 10 4 s −1 , corresponds to an extremely low level of energy dissipation from the CPW into the detector, W D = Γ ph × hf J ∼ 0.7 aW ≈ -151 dBm.…”

Section: Process Shown By the Dashed Arrow Inmentioning

confidence: 99%

“…An important basic question is therefore whether cQED behavior can be observed at high microwave frequencies. However, the required measurement is technically challenging, and dedicated microwave detection techniques [9][10][11][12][13] are necessary for a mK-setup of the dilution fridge at frequencies beyond the standard scale, f r ∼ 10 GHz.…”

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confidence: 99%

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DC measurement of dressed states in a coupled 100 GHz resonator system using a single quasiparticle transistor as a sensitive microwave detector

Lotkhov

Dolata

Khabipov

2019

Applied Physics Letters

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We report on the on-chip detection of microwaves in the frequency range around 100 GHz. For the purpose of detection, we employ a discrete transport channel triggered in a superconducting single-electron transistor by photon-assisted tunneling of quasiparticles. The technique is successfully applied to observe the spectrum of the dressed states of a model cQED system consisting of a superconducting coplanar resonator coupled to a quantum Josephson oscillator. The dressed states appear as typical resonance anticrossing exhibiting, in our case, an expectedly wide frequency splitting corresponding to the Jaynes-Cummings coupling strength, g/π ∼ 10 GHz. Due to the high decay rate, γ ∼ 20÷40 GHz, in the very transparent Josephson junctions used, the strong coupling limit, g γ, which is required for qubit operation, is not achieved, and the photon population in the resonator is low, n < 1. Remarkably, the continuous readout of the low population states demonstrates the high microwave sensitivity of the detector.

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Photon-activated electron hopping in a single-electron trap enhanced by Josephson radiation

Lotkhov

Jalali-Jafari

Zorin

2016

Applied Physics Letters

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Using a Josephson junction interferometer (DC SQUID) as a microwave source for irradiating a single-electron trap, both devices fabricated on the same chip, we study the process of photonassisted tunneling as an effective mechanism of single photon detection. High sensitivity down to a very small oscillation amplitude v J $ 10 nV ( E act Շ hf J and down to low photon absorption rates C ph $ (1-50) Hz, as well as a clear threshold type of operation with an activation energy E act $ 400 leV, is demonstrated for the trap with respect to the microwave photons of frequency f J $ (100-200) GHz. Tunable generation is demonstrated with respect to the power and frequency of the microwave signal produced by the SQUID source biased within the subgap voltage range. A much weaker effect is observed at the higher junction voltages along the quasiparticle branch of the I-V curve; this response mostly appears due to the recombination phonons. Operation of single-electron tunneling (SET) circuits is known to be significantly influenced by microwave radiation coupled to tunnel junctions. 1 The related phenomena are regularly observed in experiments in the form of noise-induced charge tunneling, and so-called photon-assisted tunneling (PAT) 2 mechanisms have been extensively studied over the last two decades, both in the normal conducting 3,4 and in the superconducting 5-10 systems with tunnel junctions. A straightforward demonstration of PAT in an electron pump has been provided in Ref. 4, where an external source of the highfrequency signal was used. Recently, several studies have been performed which involve compact experimental arrangements combining on the same chip a tunnel-junction-based source of the microwaves with a strongly coupled (also tunnel-junction-based) photon detector. 10,11 On the other hand, a dramatic reduction in the background PAT rates has been achieved with the help of a double-shielded cryogenic sample holder 12 or on-chip line filtering 13 employed for the tunneling experiments.In this letter, we report on the direct observation of the photon activated tunneling of charge in a hybrid Josephson-SET circuit, integrating on the same chip a tunable microwave source and an SET-based single-photon detector coupled to this source via a superconducting coplanar waveguide. The experimental layout is shown in Fig. 1 and includes a DC-SQUID-based Josephson oscillator, a two-wire transmission line, and a two-junction charge trap read out by an SET electrometer. 9 We demonstrate a strong effect of controllable microwave irradiation on the switching statistics in the trap. A comparison of the experimental data with the PAT theory 1,2 clearly demonstrates the quantum nature of interaction between the weak electromagnetic wave and the electron tunneling system. In contrast to our previous experiment reported in Ref. 10, the detector is placed clearly apart from the source, so that the possible acoustic (phonon-mediated) component of the signal (see, e.g., Ref. 14) reaching our detector is deliberately reduced.The oscil...

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On the residual stress developed in the nanostructure of computer simulated thin films

Cited by 3 publications

References 36 publications

Structural origins of intrinsic stress in amorphous silicon thin films

Structural origins of intrinsic stress in amorphous silicon thin films

DC measurement of dressed states in a coupled 100 GHz resonator system using a single quasiparticle transistor as a sensitive microwave detector

Photon-activated electron hopping in a single-electron trap enhanced by Josephson radiation

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