Absolute rates of vacuum-ultraviolet photochemical deposition of organic films

Stewart, Thomas B.; Arnold, Graham S.; Hall, D. F.; Marten, H. D.

doi:10.1021/j100343a037

Cited by 44 publications

(12 citation statements)

References 2 publications

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“…The activation energy for desorption can be determined from FEBIP experiments by measuring the deposition rate as a function of substrate temperature and constructing an Arrhenius plot. Christy measured E des in a FEBIP experiment for a siloxane (tetramethyl tetraphenyl trisiloxane, DC-704 pump oil) and found that the value found from the FEBIP experiment underestimates the desorption energy by a factor of two to three compared to reference values [14–15]. Li et al have performed the same measurement for WF 6 [16] and found a desorption energy that was three to five times lower than expected.…”

Section: Introductionmentioning

confidence: 99%

The role of electron-stimulated desorption in focused electron beam induced deposition

Dorp¹,

Hansen²,

Wagner³

et al. 2013

Beilstein J. Nanotechnol.

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SummaryWe present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growth rate is lower at higher substrate temperatures. From Arrhenius plots we calculated the activation energy for desorption, E des, of W(CO)6. We found an average value for E des of 20.3 kJ or 0.21 eV, which is 2.5–3.0 times lower than literature values. This difference between estimates for E des from FEBIP experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption.

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Section: Introductionmentioning

confidence: 99%

The role of electron-stimulated desorption in focused electron beam induced deposition

Dorp¹,

Hansen²,

Wagner³

et al. 2013

Beilstein J. Nanotechnol.

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“…Besides affecting light transmission loss, the aromatic groups in DC704 also impact photodeposition, fixing, and darkening. The rates of those photochemical processes are a function of many parameters including the contaminant concentration at the surface and their ability to absorb photons 11 . Once photons are absorbed, presumably leading to radical formation, the stability of those reactive species will be determined by the functional groups of the contaminant.…”

Section: Light Absorptionmentioning

confidence: 99%

Chemical analysis of silicone outgassing

Villahermosa

Ostrowski

2008

Optical System Contamination: Effects, Measurements, and Control 2008

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Silicone materials pose a contamination control challenge because of their ubiquity in satellite hardware, the tendency of the material and its outgassed contaminants to migrate along surfaces, and the difficulty in cleaning away the residue. To devise effective mitigation strategies, accurate knowledge of the chemical identity and properties of the outgassed species is needed. This information is critical for modeling silicone outgassing deposition processes and for developing effective cleaning methods. To this end, a chemical analysis study of several common silicone materials was conducted to identify and characterize the outgassed contaminants. Gas Chromatography-Mass Spectrometry (GC-MS) and other laboratory techniques were used to identify and characterize the outgassed species. In this report, the results of this study will be discussed with a particular emphasis on comparing the outgassing properties of the species collected from these materials to DC704, which is typically used to model silicone outgassing.

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“…[1][2][3][4][5] In view of this a great deal of work has been done in measuring photofixing rates for a variety of materials as a function of illumination wavelength and substrate temperature. Some in-situ measurements of the reflection /transmission changes of the substrate-film as a function of film deposition have also been performed.…”

Section: Introductionmentioning

confidence: 99%

Volatile contaminant materials: relationship between condensate, effluent and bulk composition

Ianno

Zhou

2012

SPIE Proceedings

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DC-93-500, SCV-2590 and SCV-2590-2 silicone/siloxane based co-polymers serve as adhesive components of satellites and other spacecraft. It is well known that out gassing of these materials is a major source of contamination. For the past several years we have been optically characterizing the condensates and their photofixed films via in-situ ellipsometry and quartz crystal microbalance (QCM) measurements. We have identified several common outgassed components in each of these materials via FTIR, including polydimethylsiloxane (PDMS), and Tetra-n-propylsilicate (NPS). We have studied the optical properties of the photofixed films produced at various wavelengths of incident light , as well as when mixtures of these films are employed as the outgassing source via variable angle spectroscopy ellipsometry. We can relate the photofixed material optical properties to the bulk liquids and to the films produced by the outgassssing of the actual co-polymers mentioned above. This work may lead to the evaluation of the optical properties of the photofixed effluents of actual adhesives by evaluating a few basic components

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Absolute rates of vacuum-ultraviolet photochemical deposition of organic films

Cited by 44 publications

References 2 publications

The role of electron-stimulated desorption in focused electron beam induced deposition

The role of electron-stimulated desorption in focused electron beam induced deposition

Chemical analysis of silicone outgassing

Volatile contaminant materials: relationship between condensate, effluent and bulk composition

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