scholarly journals Bonding States of Hydrogen in Plasma-Deposited Hydrocarbon Films

2020 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Wolfgang Jacob ◽  
Thomas Dürbeck ◽  
Thomas Schwarz-Selinger ◽  
Udo von Toussaint
Keyword(s):  
Hydrogen Content ◽  
Release Kinetics ◽  
Binding Energies ◽  
Hydrogen Release ◽  
Linear Temperature ◽  
Exponential Factor ◽  
Temperature Ramp ◽  
Temperature Ramps ◽  
Diffusive Effects ◽  
Temperature Programmed

We applied temperature-programmed desorption (TPD) spectroscopy to study the bonding of hydrogen in amorphous hydrogenated carbon (a–C:H) films. Typical hard plasma-deposited a–C:H films with an initial hydrogen content (H/(H+C)) of about 30% were used as samples. About 85% of the initial hydrogen content is released in the form of H2, the rest in the form of hydrocarbons. Using a temperature ramp of 15 K/min, release of hydrogen starts at about 600 K with a first peak at about 875 K and a broad shoulder around 1050 K. The peak positions depend on the temperature ramp. This fact was exploited to determine the pre-exponential factor for an analytic analysis of the release spectra. This analysis revealed a pre-exponential factor of ν = 1 × 10 16 1/s, which deviates significantly from the frequently assumed prefactor 1 × 10 13 1/s. This higher prefactor leads to a shift in the determined binding energies by about +0.5 eV. Standard TPD measurements with linear temperature ramps up to 1275 K were complemented by so-called “ramp and hold” experiments with linear ramps up to certain intermediate temperatures and holding the samples for different times at these temperatures. Such experiments provide valuable additional data for investigation of the thermal behavior of the investigated films. Our experiments prove that the width of the hydrogen release spectrum is determined by a distribution of binding energies rather than release kinetics or diffusive effects. This binding energy distribution has a peak at about 3.1 eV and a shoulder at higher energies extending from about 3.6 to 3.9 eV.

A Study of Non-Infrared-Active Hydrogen Bonding in a-Si:H Thin Film using combined Calibrated Temperature Desorption Spectroscopy and FTIR

2000 ◽  
Vol 609 ◽  
Author(s):  
DJ. Santjojo ◽  
J.C.L. Cornish ◽  
M.O.G. Talukder
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrogen Bonding ◽  
Hydrogenated Amorphous Silicon ◽  
Active Hydrogen ◽  
Linear Temperature ◽  
Silicon Thin Films ◽  
Temperature Ramp ◽  
Hydrogenated Amorphous ◽  
Hydrogen Effusion

ABSTRACTNon-infrared-active hydrogen bonding species were investigated by analyzing the infrared spectra and the calibrated temperature desorption spectroscopy (CTDS) spectra of hydrogen released during degassing of hydrogenated amorphous silicon thin films. Samples were degassed gradually using a linear temperature ramp (0.5°C/s). Each stage corresponds to a temperature at which the hydrogen effusion peaks can be found (~ 340°C, ~ 500°C and ~ 610°C). Differences in the amounts of hydrogen obtained from the FTIR spectra and the CTDS measurement correspond to the non-infrared-active, occluded hydrogen.

Moisture and Hydrogen Release in Optoelectronic Hermetic Packages

2013 ◽  
Vol 2013 (1) ◽  
pp. 000061-000066
Author(s):  
M. Albarghouti ◽  
N. El Dahdah ◽  
G. Perosevic ◽  
S. Jain ◽  
J-M Papillon ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Moisture Content ◽  
Hydrogen Content ◽  
Electroless Plating ◽  
Hydrogen Release ◽  
Surface Oxides ◽  
Sims Analysis ◽  
Electroless Ni

In this work we investigated the effect of Nickel (Ni) plating process on the Hydrogen (H) and moisture content of hermetic packages such as those used in optoelectronics. The work offers an explanation of moisture formation inside hermetic packages by showing that the problem arises from the electroless plating of Ni which is found to be inherently rich in H. The effects of the Ni plating process, baking, and Au thickness on the moisture and hydrogen content of hermetic packages were thoroughly explored. It was observed that baking the package components before sealing alleviates the problem of moisture formation inside the package but it doesn't fully eliminate it. It was only after changing the Ni plating process from electroless to electrolytic that the moisture problem actually disappeared. Our investigation showed that moisture formation inside hermetic packages is due to H evolution from the electroless Ni which eventually reacts with surface oxides to form H2O. SIMS analysis of electroless and electrolytic Ni showed that electroless Ni is around ten folds richer in H compared to its electrolytic counterpart. SIMS analysis also showed that H content in electroless Ni can be significantly reduced with heat treatment.

Moisture and Hydrogen Release in Optoelectronic Hermetic Packages

2014 ◽  
Vol 11 (2) ◽  
pp. 75-79 ◽  
Author(s):  
M. Albarghouti ◽  
N. El Dahdah ◽  
G. Perosevic ◽  
S. Jain ◽  
J.-M. Papillon ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Moisture Content ◽  
Hydrogen Content ◽  
Electroless Plating ◽  
Hydrogen Release ◽  
Surface Oxides ◽  
Sims Analysis ◽  
Electroless Ni

In this work the effect of nickel (Ni) plating process on the hydrogen (H) and moisture content of hermetic packages such as those used in optoelectronics was investigated. The work offers an explanation of moisture formation inside hermetic packages by showing that the problem arises from the electroless plating of Ni, which is found to be inherently rich in H. The effects of the Ni plating process, baking, and Au thickness on the moisture and hydrogen content of hermetic packages were thoroughly explored. It was observed that baking the package components before sealing alleviates the problem of moisture formation inside the package but does not fully eliminate it. It was only after changing the Ni plating process from electroless to electrolytic that the moisture problem actually disappeared. This investigation showed that moisture formation inside hermetic packages is due to H evolution from the electroless Ni which eventually reacts with surface oxides to form H2O. SIMS analysis of electroless and electrolytic Ni showed that electroless Ni is around 10-fold richer in H compared with its electrolytic counterpart. SIMS analysis also showed that H content in electroless Ni can be significantly reduced with heat treatment.

scholarly journals Thermal desorption of formamide and methylamine from graphite and amorphous water ice surfaces

2019 ◽  
Vol 15 (S350) ◽  
pp. 370-371
Author(s):  
Henda Chaabouni ◽  
Stephan Diana ◽  
Thanh Nguyen
Keyword(s):  
Energy Distribution ◽  
Thermal Desorption ◽  
Interstellar Dust ◽  
Binding Energies ◽  
Desorption Energy ◽  
Exponential Factor ◽  
Water Ice ◽  
Ice Surface ◽  
Crystalline Water ◽  
Best Fit

AbstractThermal desorption experiments of Formamide (NH2CHO) and methylamine (CH3NH2) were performed in LERMA-Cergy laboratory to determine the values of the desorption energies of formamide and methylamine from analogues of interstellar dust grain surfaces, and to understand their interaction with water ice. We found that more than 95 % of solid NH2CHO diffuses through the np-ASW ice surface towards the graphitic substrate, and is released into the gas phase with a desorption energy distribution Edes = (7460 – 9380) K, measured with the best-fit pre-exponential factor A=1018 s-1. Whereas, the desorption energy distribution of methylamine from the np-ASW ice surface (Edes =3850-8420 K) is measured with the best-fit pre-exponential factor A=1012s-1. A fraction of solid methylamine, of about 0.15 monolayer diffuses through the water ice surface towards the HOPG substrate, and desorbs later, with higher binding energies (5050-8420 K), which exceed that of the crystalline water ice (Edes =4930 K), calculated with the same pre-exponential factor A=1012 s-1.

scholarly journals Development of a Novel Method for the Fabrication of Nanostructured Zr(x)Ni(y) Catalyst to Enhance the Desorption Properties of MgH2

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 849
Author(s):  
Gracia Shokano ◽  
Zahir Dehouche ◽  
Basile Galey ◽  
Georgeta Postole
Keyword(s):  
Hydrogen Desorption ◽  
Milling Process ◽  
Hydrogen Release ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscope Analysis ◽  
Novel Method ◽  
Temperature Programmed ◽  
The Impact

The present work involves the development of a novel method for the fabrication of zirconium nickel (Zr(x)Ni(y)) alloy used as a nanocatalyst to improve the hydrogen storage properties of the Mg/MgH2 system. The catalyst was fabricated through the high-pressure reactor and activated under hydrogen prior to being mechanically milled with the MgH2 for 5 h under argon. The microstructure characterisation of the samples was determined via SEM-EDX (scanning electron microscope analysis–energy dispersive X-ray spectroscopy), XRD (X-ray diffraction) and FE-HRTEM (field emission high resolution transmission electron microscopy), and the desorption characteristic of the nanocomposite (10 wt.% Zr(x)Ni(y)–MgH2) was determined via TPD (temperature-programmed desorption). The nanostructured MgH2 powder milled with 10 wt.% of the activated Zr(x)Ni(y) based nanocatalyst resulted in a faster hydrogen release—5.9 H2-wt.% at onset temperature 210 °C/peak temperature 232 °C. The observed significant improvement in the hydrogen desorption properties was likely to be the result of the impact of the highly dispersed catalyst on the surface of the Mg/MgH2 system, the reduction in particle size during the ball milling process and/or the formation of Mg0.996Zr0.004 phase during the milling process.

Development of a linear temperature ramp-based automated system for furnace oxidation of semiconductor wafers

2015 ◽  
Vol 1 (4) ◽  
pp. 259
Author(s):  
Sk Abdul Kader Md Faruque ◽  
Debaleen Biswas ◽  
Shaibal Saha ◽  
Supratic Chakraborty
Keyword(s):  
Automated System ◽  
Linear Temperature ◽  
Temperature Ramp
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