Large Grain Size and High Deposition Rate for Microcrystalline Silicon Prepared by VHF-GD

1994 ◽  
Vol 358 ◽  
Author(s):  
P. Hapke ◽  
F. Finger ◽  
M. Luysberg ◽  
R. Carius ◽  
H. Wagner
Keyword(s):  
Grain Size ◽  
Deposition Rate ◽  
High Frequency ◽  
Excitation Frequency ◽  
Chemical Vapour ◽  
High Deposition Rate ◽  
Very High Frequency ◽  
Deposition Parameters ◽  
Plasma Excitation ◽  
Very High

ABSTRACTThe growth mechanism and material properties of -type µc-Si:H prepared with plasma enhanced chemical vapour deposition in the very high frequency range is investigated. By increasing the plasma excitation frequency the grain size, deposition rate and Hall mobility can be simultaneously increased without having to adjust other deposition parameters in particular the temperature. This effect is explained by an enhanced selective etching of amorphous tissue and grain boundary regions together with a sufficient supply of growth species at high frequency plasmas.

Development of p-type microcrystalline silicon carbon alloy films by the very high frequency plasma-enhanced chemical vapor deposition technique

2001 ◽  
Vol 16 (7) ◽  
pp. 2130-2135
Author(s):  
Tapati Jana ◽  
Arup Dasgupta ◽  
Swati Ray
Keyword(s):  
Substrate Temperature ◽  
High Frequency ◽  
Excitation Frequency ◽  
Deposition Technique ◽  
Very High Frequency ◽  
Silicon Carbon ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
Plasma Excitation ◽  
Very High

We developed p-type μc-silicon carbon alloy thin films by the very high frequency plasma-enhanced chemical vapour deposition technique using a SiH4, H2, CH4, and B2H6 gas mixture at low power (55 mW/cm2) and low substrate temperatures (150–250 °C). Effects of substrate temperature and plasma excitation frequency on the optoelectronic and structural properties of the films were studied. A film with conductivity 5.75 Scm−1 and 1.93 eV optical gap (E04) was obtained at a low substrate temperature of 200 °C using 63.75 MHz plasma frequency. The crystalline volume fractions of the films were estimated from the Raman spectra. We observed that crystallinity in silicon carbon alloy films depends critically on plasma excitation frequency. When higher power (117 mW/cm2) at 180 °C with 66 MHz frequency was applied, the deposition rate of the film increased to 50.7 Å/min without any significant change in optoelectronic properties.

Preparation and Characterization of Highly Conductive (100 S/cm) Phosphorus Doped νc-Si:H Films Deposited Using the VHF-GD Technique

1989 ◽  
Vol 164 ◽  
Author(s):  
Kshem Prasad ◽  
F. Finger ◽  
H. Curtins ◽  
A. Shah ◽  
J. Bauman
Keyword(s):  
Excitation Frequency ◽  
Very High Frequency ◽  
Hydrogen Dilution ◽  
Deposition Parameters ◽  
Plasma Excitation ◽  
Phosphorus Doped ◽  
Power Densities ◽  
Very High ◽  
Doping Ratio

AbstractWe report on the preparation and characterization of phosphorus doped gc-Si:H films produced by the very high frequency glow discharge (VHF-GD) at a plasma excitation frequency of 70 MHz. We present a systematic study of the deposition parameters i.e. hydrogen dilution of silane, VHF power density, gas phase doping ratio and deposition temperature and their influences on the electrical and structural properties of the material. In contrast to 13.56 MHz GD the VHF plasma conditions favour microcrystalline formation at low power densities; the resulting conductivities are significantly higher than those obtained at 13.56 MHz.

High Rate Deposition of a-SiNxH by VHF PECVD

1997 ◽  
Vol 467 ◽  
Author(s):  
T. Takagi ◽  
Y. Nakagawa ◽  
Y. Watabe ◽  
K. Takechi ◽  
S. Nishida
Keyword(s):  
Amorphous Silicon ◽  
Deposition Rate ◽  
Excitation Frequency ◽  
Chemical Vapour ◽  
Optical Emission ◽  
High Rate ◽  
Very High Frequency ◽  
Silicon Nitride Films ◽  
Very High

ABSTRACTVery High Frequency (VHF) has been applied to the plasma enhanced chemical vapour deposition (PECVD) of hydrogenated amorphous silicon nitride films (a-SiNx:H) to fabricate amorphous silicon (a-Si:H) thin film transistors (TFTs). Especially, the effect of the excitation frequency on the deposition rate and the film quality of a-SiNx.H deposited in a SiH4/NH3/N2 plasma has been investigated. The films were prepared by VHF (40 MHz and 60 MHz) and HF (13.56 MHz) plasma enhanced CVD.The optical bandgap, the hydrogen content, the Si-H/N-H ratio and TFT mobility for films deposited in VHF plasma did not change significantly with the increase in deposition rate up to 300 nm/min. Internal stress could be constrained to acceptable levels at very high deposition rates. In contrast, the film quality deteriorated with an increase of the deposition rate in HF plasma. There seems to be a parallel relation between the optical emission intensity and the deposition rate which depends on the excitation frequency.

Preparation of a-Si:H and a-SiGe:H I-Layers for Nip Solar Cells at High Deposition Rates Using a Very High Frequency Technique

1998 ◽  
Vol 507 ◽  
Author(s):  
S.J. Jones ◽  
X. Deng ◽  
T. Liu ◽  
M. Izu
Keyword(s):  
Solar Cells ◽  
Deposition Rate ◽  
High Frequency ◽  
High Efficiency ◽  
High Deposition Rate ◽  
Very High Frequency ◽  
Deposition Rates ◽  
Single Junction ◽  
Layer Deposition ◽  
Very High

ABSTRACTThe 70 MHz Plasma Enhance Chemical Vapor Deposition (PECVD) technique has been tested as a high deposition rate (10 A/s) process for the fabrication of a-Si:H and a-SiGe:H alloy ilayers for high efficiency nip solar cells. As a prelude to multi-junction cell fabrication, the deposition conditions used to make single-junction a-Si:H and a-SiGe:H cells using this Very High Frequency (VHF) method have been varied to optimize the material quality and the cell efficiencies. It was found that the efficiencies and the light stability for a-Si:H single-junction cells can be made to remain relatively constant as the i-layer deposition rate is varied from 1 to 10 Å/s. Also these stable efficiencies are similar to those for cells made at low deposition rates (1 Å/s) using the standard 13.56 MHz PECVD technique. For the a-SiGe:H cells of the same i-layer thickness, use of the VHF technique leads to cells with higher currents and an ability to more easily current match triple-junction cells prepared at high deposition rates which should lead to higher multi-junction efficiencies. Thus, use of this VHF method in the production of large area a- Si:H based multi-junction solar modules will allow for higher i-layer deposition rates, higher manufacturing throughput and reduced module cost.

Improvement of grain size and deposition rate of microcrystalline silicon by use of very high frequency glow discharge

1994 ◽  
Vol 65 (20) ◽  
pp. 2588-2590 ◽  
Author(s):  
F. Finger ◽  
P. Hapke ◽  
M. Luysberg ◽  
R. Carius ◽  
H. Wagner ◽  
...  
Keyword(s):  
Grain Size ◽  
Glow Discharge ◽  
Deposition Rate ◽  
High Frequency ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Very High

Deposition‐rate reduction through improper substrate‐to‐electrode attachment in very‐high‐frequency deposition ofa‐Si:H

1996 ◽  
Vol 80 (6) ◽  
pp. 3546-3551 ◽  
Author(s):  
H. Meiling ◽  
W. G. J. H. M. van Sark ◽  
J. Bezemer ◽  
W. F. van der Weg
Keyword(s):  
Deposition Rate ◽  
High Frequency ◽  
Rate Reduction ◽  
Very High Frequency ◽  
Very High

Silicon Carbon Alloys Produced by VHF and Conventional PECVD. A Comparison of their Properties.

1994 ◽  
Vol 336 ◽  
Author(s):  
G. Crovini ◽  
F. Demichelis ◽  
C.F. Pirri ◽  
E. Tresso ◽  
J. Meier ◽  
...  
Keyword(s):  
High Frequency ◽  
Urbach Energy ◽  
Energy Gap ◽  
Very High Frequency ◽  
Hydrogen Dilution ◽  
Deposition Parameters ◽  
Silicon Carbon ◽  
Defect Densities ◽  
Very High

ABSTRACTThe Very High Frequency (70 MHz) PECVD has recently proven its ability to produce Amorphous silicon with high deposition rates (10 Å/s) without affecting the quality of the Material. A comparative study of the optoelectronic properties of undoped silicon carbon alloys produced by Very High Frequency and by conventional RF (13.56 MHz) is carried out. Conductivity, infrared absorption, optical transmission and deep defect densities via PDS and ESR have been Measured. Deposition parameters under study aie methane fraction and hydrogen dilution. In contrast to conventional PECVD, we observe for VHF depositions an increase of the deposition rate with the addition of Methane. Larger energy gap and smaller Urbach energy values seem to indicate a better incorporation of carbon in the VHF case. A study of the degradation induced by light is also presented.

Effect of deposition rate on the growth mechanism of microcrystalline silicon thin films using very high frequency PECVD

Optik ◽  
2019 ◽  
Vol 180 ◽  
pp. 104-112 ◽  
Author(s):  
Xinli Li ◽  
Ruimin Jin ◽  
Lihua Li ◽  
Jingxiao Lu ◽  
Yongjun Gu ◽  
...  
Keyword(s):  
Thin Films ◽  
Deposition Rate ◽  
Growth Mechanism ◽  
High Frequency ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Silicon Thin Films ◽  
Very High

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.

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