Diagnostics of VHF Plasma Deposition

1992 ◽  
Vol 258 ◽  
Author(s):  
J. Kuske ◽  
U. Stephan ◽  
K. Schade ◽  
W. Fuhs
Keyword(s):  
High Frequency ◽  
Plasma Deposition ◽  
Deposition Process ◽  
Electrical Network ◽  
Very High Frequency ◽  
Electrical Connection ◽  
Reactor Construction ◽  
Parallel Plate Reactor ◽  
Very High ◽  
Deposition Conditions

ABSTRACTThe use of Very High Frequency (VHF) glow discharge for the deposition of amorphous silicon films is one approach to influencing the deposition conditions.For the experiments a capacitatively-coupled parallel plate reactor with two aluminium electrodes of 125 mm in diameter is used. The VHF is generated by means of an all-solid state amplifier which has a frequency response ranging from 250 kHz to 150 MHz. Experiments with an nitrogen discharge within the range from 5 to 150 MHz are an principle in agreement with the results in the literature. The results show, that the frequency dependence of the discharge strongly depends on the design and the external electrical connection of the VHF-reactor. In the examined range of frequency resonances appear, which are probably responsible for the maximum of the deposition rate. These resonances are not essentially resultant from changes in the physics of the discharge but a result of the reactor construction and the external electrical connection. Possibilities which influence this frequencies of resonance will be discussed.Results for an electrical network model will be discussed in the comparison with different reactors and the optimization of the behaviour of the deposition process.

Versatile High Rate Plasma Deposition and Processing with very high Frequency Excitation

1997 ◽  
Vol 467 ◽  
Author(s):  
M. Heintze
Keyword(s):  
Growth Rates ◽  
High Frequency ◽  
Plasma Deposition ◽  
Excitation Frequency ◽  
High Growth ◽  
Surface Reactivity ◽  
High Rate ◽  
Plasma Diagnostic ◽  
Very High Frequency ◽  
Very High

ABSTRACTThe interest in plasma deposition using very high frequency (VHF) excitation arose after the preparation of a-Si:H at high growth rates was demonstrated. Subsequently the improved process flexibility and the control of material properties offered by the variation of the plasma excitation frequency was recognized. The preparation of amorphous and microcrystalline thin films in a VHF-plasma is described. The increased growth rates have been attributed to an enhancement of film precursor formation at VHF, to the decreased sheath thickness as well as to an enhancement of the surface reactivity by positive ions. Plasma diagnostic investigations show that the parameters mainly affected by the excitation frequency are the ion flux to the electrodes as well as the sheaths potentials and widths, rather than the plasma density.

Size Reduction and Phosphorus Doping of Silicon Nanocrystals Prepared by a Very High Frequency Plasma Deposition System

2011 ◽  
Vol 50 (2R) ◽  
pp. 025002 ◽  
Author(s):  
Yoshifumi Nakamine ◽  
Naoki Inaba ◽  
Tetsuo Kodera ◽  
Ken Uchida ◽  
Rui N. Pereira ◽  
...  
Keyword(s):  
High Frequency ◽  
Silicon Nanocrystals ◽  
Plasma Deposition ◽  
Size Reduction ◽  
Very High Frequency ◽  
Phosphorus Doping ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
Very High

An Approach to High Quality a-Ge:H by VHF Deposition

1993 ◽  
Vol 297 ◽  
Author(s):  
Ralf Zedlitz ◽  
Moritz Heintze ◽  
Gottfried H. Bauer
Keyword(s):  
High Frequency ◽  
Parallel Plate ◽  
Charge Carriers ◽  
Substrate Plane ◽  
Very High Frequency ◽  
High Quality ◽  
Ion Energy ◽  
Preparation Conditions ◽  
Parallel Plate Reactor ◽  
Very High

Amorphous hydrogenated germanium a-Ge:H was deposited by very high frequency glow discharge (VHF-GD) at frequencies between 25 and 220MHz, low pressure (2.5Pa) and high deposition rates (≤4Á /s) on both electrodes of a parallel plate reactor. The films are comparable to material deposited on the powered electrode of a conventional RF-GD. Mobility-lifetime products ηµτ for photogenerated charge carriers around 10-7cm2/V and a Fermi level position at EC-EF≈400meV indicate good opto-electronic properties. The IR spectra show that the samples are free of oxydization and incorporate slightly more voids than the RF material. Measurements of ion energy Ei and flux Фi in the substrate plane show that “hard&” preparation conditions are obtained comparable to the deposition on the powered electrode of an RF-GD.

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