A system for in situ studies of plasma–surface interactions using x‐ray photoelectron spectroscopy

1983 ◽  
Vol 1 (3) ◽  
pp. 1452-1455 ◽  
Author(s):  
J. L. Vossen ◽  
J. H. Thomas ◽  
J.‐S. Maa ◽  
O. R. Mesker ◽  
G. O. Fowler
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Interactions ◽  
Plasma Surface ◽  
X Ray ◽  
In Situ Studies ◽  
Plasma Surface Interactions

Plasma Surface Interaction During the Growth of Semiconductor Thin Films Studied byin Situ Infrared Ellipsometry

1991 ◽  
Vol 237 ◽  
Author(s):  
N. Blayo ◽  
B. Drevillon
Keyword(s):  
Film Surface ◽  
Surface Interactions ◽  
Microcrystalline Silicon ◽  
Hydrogen Etching ◽  
Plasma Surface ◽  
Plasma Surface Interactions ◽  
Glass Substrates ◽  
Infrared Ellipsometry ◽  
Semiconductor Thin Films

ABSTRACTThe early stages of the growth of plasma deposited amorphous silicon (a-Si:H) and microcrystalline silicon (μc-Si) on glass substrates are investigated by in situ infrared phase modulated ellipsometry (IRPME) in the silicon-hydrogen stretching mode region. μc-Si are prepared by alternating SiH4 and H2 plasmas. New insights on the plasma-surface interactions during the growth of these films are given. During the deposition of the first 20 Å of a-Si:H, the hydrogen is incorporated as SiH2. During the further growth of a-Si:H the SiH2 bonds are located at the film surface inside a very thin hydrogen rich overlayer. During the deposition of the first 10–20 Å of μc-Si, the SiH2 bonds are predominantly removed by the H2 plasma, the material being amorphous. After this selective removal of the SiH2 groups, a transition from amorphous to microcrystalline growm is observed. A systematic hydrogen etching during the further growth of μc-Si is observed.

scholarly journals In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Marc Benjamin Hahn ◽  
Paul M. Dietrich ◽  
Jörg Radnik
Keyword(s):  
Dna Damage ◽  
Radiation Damage ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
In Situ Monitoring ◽  
Strong Increase ◽  
Oh Radicals ◽  
Strand Breaks ◽  
X Ray

AbstractIonizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.

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