Raman spectra investigation of the defects of chemical vapor deposited multilayer graphene and modified by oxygen plasma treatment

2016 ◽  
Vol 99 ◽  
pp. 125-130 ◽  
Author(s):  
Zongyao Li ◽  
Yu Xu ◽  
Bing Cao ◽  
Lin Qi ◽  
Shunyu He ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Raman Spectra ◽  
Oxygen Plasma ◽  
Chemical Vapor ◽  
Oxygen Plasma Treatment ◽  
Multilayer Graphene ◽  
Chemical Vapor Deposited

High Breakdown Voltage GaN HEMT Device Fabricated on Self-Standing GaN Substrate

2013 ◽  
Vol 347-350 ◽  
pp. 1535-1539
Author(s):  
Jian Jun Zhou ◽  
Liang Li ◽  
Hai Yan Lu ◽  
Ceng Kong ◽  
Yue Chan Kong ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Breakdown Voltage ◽  
Oxygen Plasma ◽  
Cutoff Frequency ◽  
Chemical Vapor ◽  
Current Gain ◽  
Organic Chemical ◽  
Oxygen Plasma Treatment ◽  
Gan Hemt ◽  
High Breakdown Voltage

In this letter, a high breakdown voltage GaN HEMT device fabricated on semi-insulating self-standing GaN substrate is presented. High quality AlGaN/GaN epilayer was grown on self-standing GaN substrate by metal organic chemical vapor deposition. A 0.8μm gate length GaN HEMT device was fabricated with oxygen plasma treatment. By using oxygen plasma treatment, gate forward working voltage is increased, and a breakdown voltage of more than 170V is demonstrated. The measured maximum drain current of the device is larger than 700 mA/mm at 4V gate bias voltage. The maximum transconductance of the device is 162 mS/mm. In addition, high frequency performance of the GaN HEMT device is also obtained. The current gain cutoff frequency and power gain cutoff frequency are 19.7 GHz and 32.8 GHz, respectively. A high fT-LG product of 15.76 GHzμm indicating that homoepitaxy technology is helpful to improve the frequency performance of the device.

Enhanced Wettability of Nanocrystalline Diamond Films for Biocoating Applications

2012 ◽  
Vol 1395 ◽  
Author(s):  
Jason H. C. Yang ◽  
Kungen Teii
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Film Surface ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Polar Component ◽  
Oxygen Plasma Treatment

ABSTRACTNanocrystalline diamond (NCD) films are prepared from Ar-rich/N2/CH4 and Ar-rich/H2/CH4 mixtures by microwave plasma-enhanced chemical vapor deposition, and further treated by microwave hydrogen and oxygen plasma exposures separately to enhance the wetting property. The hydrogen plasma treatment has small effect on the surface roughness, while the oxygen plasma treatment forms fine protrusions on the film surface. Results show that the wettability of the hydrogen plasma treated NCD film is nearly constant or little improvement as the polar component of the apparent surface free energy is close to the as-deposit NCD film. In contrast, the wettability of the oxygen plasma treated NCD film is improved dramatically such that the contact angle is reduced from 92º and 4.7º to almost 0º for water and 1-bromonaphthalene, respectively, and the polar component increases significantly to 34 mJ/m2. The low contact angle suggests that the film is considerably a cell adhesive friendly surface, which is essential in maintaining multicellular structure, and thus making it a favorable wetting surface for biological and biomedical applications.

scholarly journals Influence of Oxygen–Plasma Treatment on In-Situ SiN/AlGaN/GaN MOSHEMT with PECVD SiO2 Gate Insulator

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3968
Author(s):  
Cho ◽  
Cha ◽  
Kim
Keyword(s):  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Surface Condition ◽  
Chemical Vapor ◽  
High Electron Mobility Transistor ◽  
Gate Insulator ◽  
Oxygen Plasma Treatment ◽  
High Electron ◽  
Threshold Voltage Shift

The influence of oxygen–plasma treatment on in situ SiN/AlGaN/GaN MOS high electron mobility transistor with SiO2 gate insulator was investigated. Oxygen–plasma treatment was performed on in situ SiN, before SiO2 gate insulator was deposited by plasma-enhanced chemical vapor deposition (PECVD). DC I-V characteristics were not changed by oxygen plasma treatment. However, pulsed I-V characteristics were improved, showing less dispersion compared to non-treated devices. During short-term gate bias stress, the threshold voltage shift was also smaller in a treated device than in an untreated one. X-ray photoemission spectroscopy also revealed that SiO2 on in situ SiN with oxygen–plasma treatment has an O/Si ratio close to the theoretical value. This suggests that the oxygen plasma treatment-modified surface condition of the SiN layer is favorable to SiO2 formation by PECVD.

Control of Threshold Voltage on the Excimer Laser Annealed Poly-Si Tfts by Oxygen Plasma Treatment on Poly-Si Surface

1995 ◽  
Vol 397 ◽  
Author(s):  
Jae-Ik Woo ◽  
Sang-Gul Lee ◽  
Dae-Gyu Moon ◽  
Chan-Hee Hong ◽  
Hoe-Sup Soh
Keyword(s):  
Plasma Treatment ◽  
Excimer Laser ◽  
Threshold Voltage ◽  
Oxygen Plasma ◽  
Treatment Time ◽  
Chemical Vapor ◽  
Gate Insulator ◽  
Oxygen Plasma Treatment ◽  
Oxide Deposition ◽  
Pressure Chemical

ABSTRACTOxygen plasma treatment was performed on the excimer laser annealed poly-Si surface, followed by gate oxide deposition with low pressure chemical vapor deposition (LPCVD) in order to control the threshold voltage of excimer laser annealed poly-Si thin film transistors (TFTs).Threshold voltages of n-channel TFTs increase from 0.4 to 2.8 V by varying the treatment time from 0 to 7 min. It is shown the effective charge density increased toward negative direction with increase of the treatment time.In addition to the increase of threshold voltage, the oxygen plasma treatment on the Si surface led to an increase in the deposition rate of LPCVD oxide films with an apparent reduction of carbon around the interface between gate insulator and poly-Si film after oxygen plasma treatment.

scholarly journals Hydrophobic modification of bacterial cellulose using oxygen plasma treatment and chemical vapor deposition

Cellulose ◽  
2020 ◽  
Vol 27 (18) ◽  
pp. 10733-10746 ◽  
Author(s):  
Salomé Leal ◽  
Cecília Cristelo ◽  
Sara Silvestre ◽  
Elvira Fortunato ◽  
Aureliana Sousa ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Plasma Treatment ◽  
Bacterial Cellulose ◽  
Vapor Deposition ◽  
Oxygen Plasma ◽  
Chemical Vapor ◽  
Oxygen Plasma Treatment ◽  
Hydrophobic Modification

scholarly journals The Amorphization of Monolayer MoS2 Induced by Strong Oxygen Plasma Treatment

2019 ◽  
Vol 26 (2) ◽  
pp. 143-146
Author(s):  
Jian-Ling MENG ◽  
Jian-Qi ZHU ◽  
Shun-Tian JIA ◽  
Xiao REN
Keyword(s):  
Visible Light ◽  
Plasma Treatment ◽  
Raman Spectra ◽  
Photoelectron Spectroscopy ◽  
Oxygen Plasma ◽  
Oxygen Plasma Treatment ◽  
Visible Light Photocatalysis ◽  
Monolayer Mos2 ◽  
X Ray ◽  
Raman Modes

By strong oxygen plasma treatment on monolayer MoS2, we observe the disappearance of the Raman modes of MoS2. We propose the hypothesis that the state of MoS2 translates from crystal to amorphous after strong oxygen plasma treatment. The evidences of no MoO3 formation shown by Raman spectra and the appearance of the Mo6+ peak and decreased O concentration shown by X-ray photoelectron spectroscopy support our hypothesis. The amorphization of monolayer MoS2 is further confirmed by the quenching of photoluminescence (PL) and the disappearance of two absorption peaks related to A, B exciton which demonstrates the disordered bandgap. Finally, we found that the amorphous MoS2 can improve the absorption fraction at the visible light (500~ 750 nm) which is potential for future visible light photocatalysis.

LDI-MS examination of oxygen plasma modified polymer for designing tailored implant biointerfaces

RSC Advances ◽  
2014 ◽  
Vol 4 (50) ◽  
pp. 26240-26243 ◽  
Author(s):  
M. Gołda-Cępa ◽  
N. Aminlashgari ◽  
M. Hakkarainen ◽  
K. Engvall ◽  
A. Kotarba
Keyword(s):  
Plasma Treatment ◽  
Oxygen Plasma ◽  
Oxygen Plasma Treatment ◽  
Parylene C ◽  
Modified Polymer

A versatile parylene C coating for biomaterials was fabricated by the mild oxygen plasma treatment and examined by the use of LDI-MS..

scholarly journals Influence of plasma treatment on SiO2/Si and Si3N4/Si substrates for large-scale transfer of graphene

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Lukose ◽  
M. Lisker ◽  
F. Akhtar ◽  
M. Fraschke ◽  
T. Grabolla ◽  
...  
Keyword(s):  
Large Scale ◽  
Oxygen Plasma ◽  
Chemical Vapor ◽  
Limiting Factors ◽  
Adhesion Properties ◽  
Si Substrates ◽  
Wetting Contact Angle ◽  
Angle Measurements ◽  
Chemical Vapor Deposited ◽  
Contact Angle Measurements

AbstractOne of the limiting factors of graphene integration into electronic, photonic, or sensing devices is the unavailability of large-scale graphene directly grown on the isolators. Therefore, it is necessary to transfer graphene from the donor growth wafers onto the isolating target wafers. In the present research, graphene was transferred from the chemical vapor deposited 200 mm Germanium/Silicon (Ge/Si) wafers onto isolating (SiO2/Si and Si3N4/Si) wafers by electrochemical delamination procedure, employing poly(methylmethacrylate) as an intermediate support layer. In order to influence the adhesion properties of graphene, the wettability properties of the target substrates were investigated in this study. To increase the adhesion of the graphene on the isolating surfaces, they were pre-treated with oxygen plasma prior the transfer process of graphene. The wetting contact angle measurements revealed the increase of the hydrophilicity after surface interaction with oxygen plasma, leading to improved adhesion of the graphene on 200 mm target wafers and possible proof-of-concept development of graphene-based devices in standard Si technologies.

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