The improved stability of hydrogenated amorphous silicon films grown by reactive magnetron sputtering at high substrate temperature

1994 ◽  
Vol 75 (7) ◽  
pp. 3704-3706 ◽  
Author(s):  
Y. H. Liang ◽  
N. Maley ◽  
J. R. Abelson
2012 ◽  
Vol 1426 ◽  
pp. 301-306
Author(s):  
Samuel J. Levang ◽  
James R. Doyle

ABSTRACTHydrogenated amorphous silicon-germanium alloy thin films (a-Si1-xGex:H) were deposited using reactive magnetron sputtering. Dual targets of silicon and germanium were sputtered in an argon + hydrogen atmosphere using rf excitation. Films with x = 0.4 were deposited as a function of substrate temperature and hydrogen partial pressure, and were evaluated by dark and photoconductivity, infrared absorption, and optical transmission. Photosensitivity reached a maximum value of about 5000 between 150 and 200 °C. Using the stretching modes in the region of 2000 cm-1, the hydrogen bonding was characterized in terms of the preferential attachment ratio (PA), which represents the ratio of H bonded to silicon to that bonded to germanium. The PA shows a systematic increase with increasing temperature, independent of hydrogen partial pressure. The interplay between thermodynamic and kinetics effects in determining PA and film quality will be discussed.


1993 ◽  
Vol 73 (11) ◽  
pp. 7435-7440 ◽  
Author(s):  
Ratnabali Banerjee ◽  
Sukriti Ghosh ◽  
S. Chattopadhyay ◽  
A. K. Bandyopadhyay ◽  
P. Chaudhuri ◽  
...  

1993 ◽  
Vol 297 ◽  
Author(s):  
Y. H. Liang ◽  
N. Maley ◽  
J. R. Abelson

We report the electronic properties, stability and microstructure of a-Si:H films grown at very high substrate temperature (Ts = 320∼425°C) by DC reactive magnetron sputtering (RMS). The partial pressures of Ar and H2 are fixed at 1.5 and 0.8 mT, respectively, during the deposition. The initial defect state density, determined by the constant photocurrent method (CPM), varies from 2∼5×l015 cm−3with H content changing from 15–10 at.% as Ts increases from 320–375°C. For 100 hrs white light exposure at lW/cm2, a heavily degraded state was obtained with mid–gap state density in the range 2-3×l016cm−3 over this Ts range. These are among the lowest values reported for intrinsic a–Si:H.


1996 ◽  
Vol 420 ◽  
Author(s):  
W. Futako ◽  
I. Shimizu ◽  
C. M. Fortmann

AbstractHydrogenated amorphous silicon (a-Si:H) with a gaps narrower than 1.7 eV were made by repeating the deposition of a thin layer (1–3 nm thick) and the treatment of growing surface with a mixture of H and Ar*. Crystallization induced by permeation of hydrogen into the subsurface at high substrate temperature (>200C) was efficiently prevented by treating with a mixture of H and Ar*. The activation of growing surface may arise from releasing a part of hydrogen on surface by treating with Ar*. High quality a-Si:H films containing hydrogen of 3 atom % with a gap of 1.6 eV were made by chemical annealing with a mixture of H and Ar*.


1992 ◽  
Vol 283 ◽  
Author(s):  
R. Carluccio ◽  
A. Pecora ◽  
G. Fortunato ◽  
J. Stoemenos ◽  
N. Economou

ABSTRACTExcimer laser crystallization of hydrogenated amorphous silicon has been investigated as a function of substrate temperature. At low substrate temperatures hydrogen out-diffusion strongly influences the film morphology, while at 420 °C homogeneous recrystallized films are obtained, as a result of the reduced solidification velocity. This process has been successfully tested by fabricating with the recrystalllized material thin-film transistors according to the bottom-gate configuration.


1992 ◽  
Vol 258 ◽  
Author(s):  
Gautam Ganguly ◽  
Akihisa Matsuda

ABSTRACTThe idea of surface mobility of growth precursors determined material quality has been exploited by raising the substrate temperature above the conventional 250°C and the ensuing thermal depletion of the surface hydrogen coverage compensated by increasing the precursor flux (deposition rate) to prepare ultra low defect density hydrogenated amorphous silicon.


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