Investigation of the Amorphous to Nanocrystalline Phase Transition at the Deposition of Silicon Films in an ECWR Plasma of Pure SiH4

1996 ◽  
Vol 420 ◽  
Author(s):  
M. Scheib ◽  
B. Schrcder ◽  
H. Oechsner
Keyword(s):  
Phase Transition ◽  
Chemical Vapour ◽  
Optical Emission ◽  
Nanocrystalline Silicon ◽  
Nanocrystalline Phase ◽  
Plasma Parameters ◽  
Deposition Rates ◽  
High Hydrogen ◽  
Hydrogen Dilution ◽  
Wave Resonance

AbstractA novel plasma based chemical vapour deposition (PECVD) technique employing electron cyclotron wave resonance (ECWR) for plasma excitation was applied to the deposition of hydrogenated nanocrystalline silicon (nc-Si:H) films. nc-Si:H films were produced at deposition rates up to 8Å/sec (TS = 200°C) with a pure SiH4 plasma in contrast to the conventional glow discharge technique where the high hydrogen dilution usually needed leads to considerable lower deposition rates. The amorphous-to-nanocrystalline phase transition was investigated in dependence of substrate temperature, the hf-power and magnetic field mandatory for ECWR, and SiH4-flow into the plasma. With the knowledge of the plasma parameters derived from single probe measurements, and the intensities of excited plasma species detected by means of optical emission spectroscopy we can qualitatively describe the silane-plasma dissociation behaviour. The nanocrystalline phase is found to be always deposited when the dissociation degree of the SiH4 plasma is almost saturated.

scholarly journals Correlation of Impedance Matching and Optical Emission Spectroscopy during Plasma-Enhanced Chemical Vapor Deposition of Nanocrystalline Silicon Thin Films

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 305 ◽  
Author(s):  
Li-Han Kau ◽  
Hung-Jui Huang ◽  
Hsueh-Er Chang ◽  
Yu-Lin Hsieh ◽  
Chien-Chieh Lee ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Impedance Matching ◽  
Chemical Vapor ◽  
Optical Emission ◽  
Nanocrystalline Silicon ◽  
Plasma Parameters ◽  
Hydrogen Dilution

In this paper, the correlation of impedance matching and optical emission spectroscopy during plasma-enhanced chemical vapor deposition (PECVD) was systematically investigated in SiH4 plasma diluted by various hydrogen dilution ratios. At the onset of nanocrystallinity in SiH4− depleted plasma condition, the SiH+ radical reached a threshold value as the dominant radical, such that a-Si to nc-Si transition was obtained. Furthermore, the experimental data of impedance analysis showed that matching behavior can be greatly influenced by variable plasma parameters due to the change of various hydrogen dilution ratios, which is consistent with the recorded optical emission spectra (OES) of Hα* radicals. Quadruple mass spectrometry (QMS) and transmission electron microscopy (TEM) were employed as associated diagnostic and characterization tools to confirm the phase transformation and existence of silicon nanocrystals.

scholarly journals Influence of Hydrogen Dilution of Silane on the Properties of nc-Si:H Films Grown by Layer-by-Layer Deposition Technique

2007 ◽  
Vol 31 ◽  
pp. 80-82 ◽  
Author(s):  
Goh Boon Tong ◽  
Siti Meriam Ab. Gani ◽  
Saadah Abdul Rahman
Keyword(s):  
Raman Scattering ◽  
Energy Gap ◽  
Nanocrystalline Silicon ◽  
Flow Rate Ratio ◽  
Layer By Layer ◽  
Deposition Technique ◽  
Crystal Silicon ◽  
High Hydrogen ◽  
Nanocrystallite Size ◽  
Hydrogen Dilution

Hydrogenated nanocrystalline silicon (nc-Si:H) films produced by layer-by-layer (LBL) deposition technique were studied. The films were grown at different hydrogen to silane flow-rate ratio on crystal silicon (111) substrate. The properties of films were investigated by X-ray diffraction (XRD), micro-Raman scattering spectroscopy, Fourier transform infrared (FTIR) spectroscopy, optical transmission spectroscopy, atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). These properties showed dependence on the hydrogen dilution of silane. Appearance of XRD peaks at diffraction angles of 28.4 o and 56.1 o which correspond to silicon orientation of (111) and (311) respectively, were observed in all films indicating evidence of crystallinity in the films. Raman scattering results indicated that crystallinity in the films was due to the presence of nanocrystallites embedded in an amorphous matrix. The energy gap of the films showed dependence on the hydrogen content in the films. Increase in nanocrystallite size resulted in increase in disorder at low hydrogen dilution films but films remain homogenous with increase in nanocrystallite size for the high hydrogen dilution films.

Nanostructured silicon films produced by PECVD

2001 ◽  
Vol 664 ◽  
Author(s):  
R. Martins ◽  
H. Águas ◽  
V. Silva ◽  
I. Ferreira ◽  
A. Cabrita ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Chemical Vapour ◽  
General Rule ◽  
Silicon Films ◽  
Process Conditions ◽  
Low Density ◽  
High Hydrogen ◽  
Hydrogen Dilution ◽  
Nanostructured Silicon ◽  
Powder Formation

ABSTRACTThis paper presents the process conditions that lead to the production of nanostructured silicon films grown by plasma enhanced chemical vapour deposition close to the so-called gamma regime (powder formation), highly dense and with low density of bulk states. Thus, the powder management is one important issue to be addressed in this paper. As a general rule we observed that high quality films (low density of states and high μτ products) are obtained when films are grown under low ion bombardment at high hydrogen dilution and deposition pressure conditions, to allow the proper surface passivation and surface activation.

Low Substrate Temperature Deposition of Crystalline SiC using HWCVD

2005 ◽  
Vol 862 ◽  
Author(s):  
S. Klein ◽  
R. Carius ◽  
L. Houben ◽  
F. Finger
Keyword(s):  
Band Gap ◽  
Crystalline Silicon ◽  
Chemical Vapour ◽  
Structural Disorder ◽  
Dark Conductivity ◽  
Band Gap Energy ◽  
Crystalline Material ◽  
High Hydrogen ◽  
Hydrogen Dilution ◽  
Columnar Grains

AbstractMicrocrystalline silicon carbide (μc-SiC) was prepared at substrate temperatures between 300°C and 450°C using Hot Wire Chemical Vapour Deposition (HWCVD). The SiC films were deposited from monomethylsilane (MMS) diluted in hydrogen on glass and crystalline silicon substrates. The influence of the hydrogen dilution on the deposition rate and the structural and the optoelectronic properties was investigated. Infrared and Raman spectroscopy and transmission electron microscopy (TEM) were applied to study the structural properties. Highly crystalline material with large columnar grains was obtained at high hydrogen dilutions. The optical absorption below the band gap is high and the dark conductivities are far above the values expected for intrinsic SiC. At lower hydrogen dilution, less crystalline or amorphous Si1-xCx is growing, showing broader IR- and Raman peaks, lower dark conductivity and higher absorption above the band gap energy. An extended nucleation zone with large structural disorder was observed even for highly crystalline material.

Injection Electroluminescence from Thin Film p-i-n Structures made from Nanocrystalline Hydrogenated Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
A. A. Andreev ◽  
B. Y. Averbouch ◽  
P. Mavlyanov ◽  
S. B. Aldabergenova ◽  
M. Albrecht ◽  
...  
Keyword(s):  
Amorphous Matrix ◽  
Volume Fraction ◽  
Interband Transition ◽  
Stokes Shift ◽  
Chemical Vapour ◽  
Nanocrystalline Silicon ◽  
Film Structure ◽  
High Hydrogen ◽  
Fast Kinetics ◽  
Deposition Parameter

AbstractNanocrystalline silicon films are prepared by plasma enhanced chemical vapour deposition of silane under the conditions of high hydrogen dilution (3:100). The film structure consists of nanoclusters 0.8 to 5 nm in size (volume fraction 30%) embedded in an amorphous matrix. The Taue gap of the amorphous matrix is 1.95 to 2.05 eV depending on deposition parameter. These films are characterized as regards photoluminescence (PL) and, prepared to p-i-n structures, electroluminescence (EL). The PL and EL agree in (i) luminescence peak at 1.9 eV, i.e. small Stokes shift, (ii) almost no temperature dependence between 77 K and 293 K, (iii) fast kinetics with time constant of a few 10−8 s. These data can be understood in terms of quantum confinement in Si nanocrystallites smaller than around 2 nm. The EL in addition exhibits a luminescence band extending up to 3 eV, which can be interpreted by interband transition due the hot carriers.

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