Fast growth of amorphous silicon layers by amplitude modulation PECVD

2000 ◽  
Vol 609 ◽  
Author(s):  
A. C. W. Biebericher ◽  
J. Bezemer ◽  
W. F. van der Weg ◽  
W. J. Goedheer
Keyword(s):  
Amorphous Silicon ◽  
Deposition Rate ◽  
Fluid Model ◽  
Modulation Frequency ◽  
Chemical Vapor ◽  
Optical Emission ◽  
High Energy ◽  
High Energy Electrons ◽  
Large Production ◽  
Rf Signal

ABSTRACTHydrogenated amorphous silicon has been deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) with a square wave amplitude modulated rf signal of 50 MHz. We studied the dependence of the deposition rate on the modulation frequency, using optical emission spectroscopy and plasma modeling. We observed an enhancement in deposition rate by modulating the plasma. This behavior is explained by the characteristics of the electronenergy distribution during the periodical onset of the plasma. According to a one-dimensional fluid model, high-energy electrons cause a large production of radicals at the onset. The heating occurs over the whole plasma volume, leading to an increase of the homogeneity of the layers. The discharge structure is changed completely. A comparison is made between results obtained at 13.56 MHz and at 50 MHz deposition voltages.

Emission spectra study of plasma enhanced chemical vapor deposition of intrinsic, n+, and p+ amorphous silicon thin films

2013 ◽  
Vol 1536 ◽  
pp. 133-138
Author(s):  
I-Syuan Lee ◽  
Yue Kuo
Keyword(s):  
Deposition Rate ◽  
Gas Flow ◽  
Emission Spectra ◽  
Chemical Vapor ◽  
Critical Factor ◽  
Optical Emission ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Silicon Thin Films ◽  
Deposition Processes

ABSTRACTThe PECVD intrinsic, n+, and p+ a-Si:H thin film deposition processes have been studied by the optical emission spectroscope to monitor the plasma phase chemistry. Process parameters, such as the plasma power, pressure, and gas flow rate, were correlated to SiH*, Hα*, and Hβ* optical intensities. For all films, the deposition rate increases with the increase of the SiH* intensity. For the doped films, the Hα*/SiH* ratio is a critical factor affecting the resistivity. The existence of PH3 or B2H6 in the feed stream enhances the deposition rate. Changes of the free radicals intensities can be used to explain variation of film characteristics under different deposition conditions.

The Effect of Plasma Power on the Properties of Amorphous Silicon-Germanium Thin Films

2011 ◽  
Vol 317-319 ◽  
pp. 341-344
Author(s):  
Long Gu ◽  
Hui Dong Yang ◽  
Bo Huang
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Deposition Rate ◽  
Silicon Germanium ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
Plasma Power ◽  
Glass Substrates ◽  
Frequency Plasma ◽  
Amorphous Silicon Germanium

Amorphous Silicon-germanium films were prepared by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) on glass substrates. The structural characteristics, deposition rate, photosensitivity, and optical band gap of the silicon-germanium thin films were investigated with plasma power varying from 15W to 45W. The deposition rate increased within a certain range of plasma power. With the plasma power increasing, the photosensitivity of the thin films decreased. It is evident that varying the plasma power changes the deposition rate, photosensitivity, which was fundamentally crucial for the fabrication of a-Si/a-SiGe/a-SiGe stacked solar cells. For our deposition system, the most optimization value was 30-35W.

scholarly journals Multi-wavelength Behaviour of III Zw2

2002 ◽  
Vol 19 (1) ◽  
pp. 73-76
Author(s):  
Nikita Salvi ◽  
Mat J. Page ◽  
Jason A. Stevens ◽  
Keith O. Mason ◽  
Kinwah Wu
Keyword(s):  
Synchrotron Radiation ◽  
Optical Emission ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
High Energy Electrons ◽  
Photon Index ◽  
Multi Wavelength ◽  
Wavelength Light ◽  
Gaussian Line

AbstractIII Zw2 was observed with XMM-Newton in July 2000. Its X-ray spectrum can be described by a power law of photon index Γ≈1.7 with a Gaussian line at 6.7 KeV. There is no significant evidence of intrinsic absorption within the source or of a soft X-ray excess. Multi-wavelength light curves over a period of 25 years show related variations from the radio to X-rays. We interpret the radio to optical emission as synchrotron radiation, self-absorbed in the radio/millimetre region, and the X-rays as mainly due to Compton up-scattering of low energy photons by the population of high energy electrons that give rise to the synchrotron radiation.

Electron spin resonance studies of microcrystalline and amorphous silicon irradiated with high energy electrons

2006 ◽  
Vol 352 (9-20) ◽  
pp. 1020-1023 ◽  
Author(s):  
Oleksandr Astakhov ◽  
Friedhelm Finger ◽  
Reinhard Carius ◽  
Andreas Lambertz ◽  
Yuri Petrusenko ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Amorphous Silicon ◽  
Electron Spin ◽  
High Energy ◽  
High Energy Electrons ◽  
Spin Resonance

High Deposition Rate Amorphous Silicon Solar Cells and Thin Film Transistors Using the Pulsed Plasma Pecvd Technique

1998 ◽  
Vol 507 ◽  
Author(s):  
Scott Morrison ◽  
Jianping Xi ◽  
Arun Madan
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Deposition Rate ◽  
Continuous Wave ◽  
Modulation Frequency ◽  
Thin Film Transistor ◽  
High Deposition Rate ◽  
Pulsed Plasma ◽  
Active Matrix ◽  
Active Matrix Displays

ABSTRACTThe pulsed plasma technique has been shown to increase the deposition rate without an increase in the particulate count in the plasma which is an important factor determining the yield of commercial products such as active matrix displays. In this paper, we report the deposition of amorphous silicon at deposition rates of up to 15 Å/sec, using a modulation frequency in the range of 1-100kHz. These materials have been incorporated into a simple p/i/n solar cell and thin film transistor (TFT) configurations. We report on the effect of the conversion efficiency as a function of the modulation frequency, which in turn is related to the deposition rate. We also report on the TFT performance with modulation frequency and compare the results with devices made under the conventional continuous wave PECVD plasma at 13.56MHz.

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.

Influence of the Electrode Spacing on the Plasma Characteristics and Hydrogenated Amorphous Silicon Film Properties Grown in the DC Saddle Field PECVD System

2011 ◽  
Vol 1321 ◽  
Author(s):  
Keith R. Leong ◽  
Nazir P. Kherani ◽  
Stefan Zukotynski
Keyword(s):  
Amorphous Silicon ◽  
Plasma Deposition ◽  
Silicon Film ◽  
Chemical Vapor ◽  
High Energy ◽  
Electrode Spacing ◽  
Film Properties ◽  
Amorphous Silicon Film ◽  
Dc Saddle Field ◽  
Ion Species

ABSTRACTA new plasma deposition system was built with the capability of varying the electrode spacing in the DC Saddle Field plasma enhanced chemical vapor deposition system. An ion mass spectrometer was installed just below the substrate holder to sample the ion species travelling towards the substrate. Silane plasma and amorphous silicon film studies were conducted to shed light on the impinging ion species, ion energy distributions, and film properties with varying electrode spacing. The results indicate that decreasing the distance between the substrate and cathode leads to a reduction in the high energy ion bombardment.

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