IN-SITU SPECTRAL ANALYSIS OF VERY HIGH  FREQUENCY GLOW DISCHARGE (VHF-GD)

The intensities of SiH*, [Formula: see text] and H* of VHF-GD for depositing μc-Si:H were much higher than those of RF-GD for depositing a-Si:H. The SiH* intensity of VHF-GD became higher than its Si* intensity as the hydrogen dilution ratio decreased. The influences of the hydrogen dilution ratio on the plasma optical emission spectra also depended on the reaction pressure, the excitation power as well as the excitation frequency.

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PREPARATION OF DIAMOND FILMS BY DC ARC DISCHARGE AND IN SITU MEASUREMENTS OF THE PLASMA BY OPTICAL EMISSION SPECTRA

Acta Physica Sinica ◽

10.7498/aps.39.1965 ◽

1990 ◽

Vol 39 (12) ◽

pp. 1965

Author(s):

ZHANG FANG-QING ◽

ZHANG YA-FEI ◽

YANG YING-HU ◽

LI JING-QI ◽

CHEN GUANG-HUA ◽

...

Keyword(s):

Arc Discharge ◽

Diamond Films ◽

Emission Spectra ◽

Optical Emission ◽

In Situ Measurements ◽

Dc Arc ◽

Optical Emission Spectra

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On the Etching Mechanism of Highly Hydrogenated SiN Films by CF4/D2 Plasma: Comparison with CF4/H2

Coatings ◽

10.3390/coatings11121535 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1535

Author(s):

Shih-Nan Hsiao ◽

Thi-Thuy-Nga Nguyen ◽

Takayoshi Tsutsumi ◽

Kenji Ishikawa ◽

Makoto Sekine ◽

...

Keyword(s):

Substrate Temperature ◽

Etch Rate ◽

Emission Spectra ◽

Optical Emission ◽

In Situ Monitoring ◽

Photoelectron Spectra ◽

Hydrogen Atoms ◽

Hydrogen Dissociation ◽

Optical Emission Spectra

With the increasing interest in dry etching of silicon nitride, utilization of hydrogen-contained fluorocarbon plasma has become one of the most important processes in manufacturing advanced semiconductor devices. The correlation between hydrogen-contained molecules from the plasmas and hydrogen atoms inside the SiN plays a crucial role in etching behavior. In this work, the influences of plasmas (CF4/D2 and CF4/H2) and substrate temperature (Ts, from −20 to 50 °C) on etch rates (ERs) of the PECVD SiN films were investigated. The etch rate performed by CF4/D2 plasma was higher than one obtained by CF4/H2 plasma at substrate temperature of 20 °C and higher. The optical emission spectra showed that the intensities of the fluorocarbon (FC), F, and Balmer emissions were stronger in the CF4/D2 plasma in comparison with CF4/H2. From X-ray photoelectron spectra, a thinner FC layer with a lower F/C ratio was found in the surface of the sample etched by the CF4/H2 plasma. The plasma density, gas phase concentration and FC thickness were not responsible for the higher etch rate in the CF4/D2 plasma. The abstraction of H inside the SiN films by deuterium and, in turn, hydrogen dissociation from Si or N molecules, supported by the results of in situ monitoring of surface structure using attenuated total reflectance-Fourier transform infrared spectroscopy, resulted in the enhanced ER in the CF4/D2 plasma case. The findings imply that the hydrogen dissociation plays an important role in the etching of PECVD-prepared SiN films when the hydrogen concentration of SiN is higher. For the films etched with the CF4/H2 at −20 °C, the increase in ER was attributed to a thinner FC layer and surface reactions. On the contrary, in the CF4/D2 case the dependence of ER on substrate temperature was the consequence of the factors which include the FC layer thickness (diffusion length) and the atomic mobility of the etchants (thermal activation reaction).

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Effects of Hydrogen Dilution Ratio on Properties of Hydrogenated Nanocrystalline Cubic Silicon Carbide Films Deposited by Very High-Frequency Plasma-Enhanced Chemical Vapor Deposition

Japanese Journal of Applied Physics ◽

10.1143/jjap.46.l693 ◽

2007 ◽

Vol 46 (No. 28) ◽

pp. L693-L695 ◽

Cited By ~ 17

Author(s):

Shinsuke Miyajima ◽

Makoto Sawamura ◽

Akira Yamada ◽

Makoto Konagai

Keyword(s):

Vapor Deposition ◽

High Frequency ◽

Chemical Vapor ◽

Dilution Ratio ◽

Very High Frequency ◽

Hydrogen Dilution ◽

High Frequency Plasma ◽

Frequency Plasma ◽

Cubic Silicon Carbide ◽

Very High

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

MRS Proceedings ◽

10.1557/proc-164-27 ◽

1989 ◽

Vol 164 ◽

Cited By ~ 26

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.

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High Rate Deposition of a-SiNxH by VHF PECVD

MRS Proceedings ◽

10.1557/proc-467-483 ◽

1997 ◽

Vol 467 ◽

Cited By ~ 4

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.

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In situ observation of nucleation by optical emission spectra in CVD diamond

Diamond and Related Materials ◽

10.1016/j.diamond.2009.10.009 ◽

2010 ◽

Vol 19 (1) ◽

pp. 15-20 ◽

Cited By ~ 3

Author(s):

G.C. Chen ◽

B. Li ◽

H. Li ◽

X.Q. Han ◽

L.F. Hei ◽

...

Keyword(s):

Emission Spectra ◽

Optical Emission ◽

Cvd Diamond ◽

In Situ Observation ◽

Optical Emission Spectra

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In-situ monitoring of optical emission spectra for microscopic pores in metal additive manufacturing Submitted for Publication

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4051532 ◽

2021 ◽

pp. 1-21

Author(s):

Wenbo Sun ◽

Zhenhao Zhang ◽

Wenjing Ren ◽

Jyoti Mazumder ◽

Jionghua (Judy) Jin

Keyword(s):

Additive Manufacturing ◽

Emission Spectra ◽

Optical Emission ◽

In Situ Monitoring ◽

Melt Pool ◽

Multiple Processes ◽

Melt Pool Temperature ◽

Optical Emission Spectra

Abstract Quality assurance techniques are increasingly demanded in additive manufacturing. Going beyond most of the existing research that focuses on the melt pool temperature monitoring, we develop a new method that monitors the in-situ optical emission spectra signals. Optical emission spectra signals have been showing a potential capability of detecting microscopic pores. The concept is to extract features from the optical emission spectra via deep auto-encoders, and then cluster the features into two quality groups to consider both unlabelled and labelled samples in a semi-supervised manner. The method is integrated with multitask learning to make it adaptable for the samples collected from multiple processes. Both a simulation example and a case study are performed to demonstrate the effectiveness of the proposed method.

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High sampling rate thermistor string observations at the slope of Great Meteor Seamount

Ocean Science ◽

10.5194/os-1-17-2005 ◽

2005 ◽

Vol 1 (1) ◽

pp. 17-28 ◽

Cited By ~ 16

Author(s):

H. van Haren ◽

R. Groenewegen ◽

M. Laan ◽

B. Koster

Keyword(s):

High Frequency ◽

North Atlantic Ocean ◽

Sampling Rate ◽

Very High Frequency ◽

High Sampling ◽

High Sampling Rate ◽

In Situ Calibration ◽

Great Meteor Seamount ◽

Very High

Abstract. A high sampling rate (1 Hz) thermistor string has been built to accommodate the scientific need to accurately monitor high-frequency and vigorous internal wave and overturning processes in the ocean. The thermistors and their custom designed electronics can register temperature at an estimated precision of about 0.001° C with a response time faster than 0.25 s down to depths of 6000 m. With a quick in situ calibration using SBE 911 CTD an absolute accuracy of 0.005° C is obtained. The present string holds 128 sensors at 0.5 m intervals, which are all read-out within 0.5 s. When sampling at 1 Hz, the batteries and the memory capacity of the recorder allow for deployments of up to 2 weeks. In this paper, the instrument is described in some detail. Its performance is illustrated with examples from the first moored observations, which show Kelvin-Helmholtz overturning and very high-frequency (Doppler-shifted) internal waves besides occasionally large turbulent bores moving up the sloping side of Great Meteor Seamount, Canary Basin, North-Atlantic Ocean.

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